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PUBLISHED BY THE AMERICAN WELDING SOCIETY TO ADVANCE THE SCIENCE, TECHNOLOGY AND APPLICATION OF WELDING

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w w w . o e r l i k o n w e l d . c o r n Circ le No. 27 on R e a d e r I n f o - C a r d

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THE WELDING SOLUTIONS PEOPLE STRIP CLADDING SYSTEMS

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T h e r m a l cttlliH~ processes, f r o m the very mob i l e m a n u a l torch to the h igh ly a u t o m a t e d laser, are essent ia l to m e t a l fabr ica t ion .

Feature Ar t i c les Weld Shop Keeps U.S. Coast Guard Always Ready The timely repair and maintenance of Coast Guard vessels ensures their readiness for law enforcement duties along the coast of Florida/31

Inverter-Based GTA Welding Machines Improve Fabrication M. Sammons An update on gas tungsten arc power sources explains the major advances in arc control and reliability made by these machines/35

Steel Center Consolidates Cutting Operations to Cut Costs A plate processing company installs a plasma arc cutting system with multiple capabilities, including cutting 6-in.-thick stainless steel/41

Repairing an Offshore Jacket Structure Proves Cost Effective J. R. Still and V. Blackwood Damage to an offshore structure required immediate weld repair and a whole lot of cooperation from the weather/43

Welding Research S u p p l e m e n t

Partially Melted Zone in Aluminum Welds m Liquation Mechanism and Directional Soldification C. Huang and S. Kou An in-depth study of grain boundary liquation during gas metal arc welding aluminum offers insight into the prevention of hot cracking/113-s

Finite Element Analysis of Heat Flow in Single-Pass Arc Welds E. A. Bonifaz A finite element model is developed to predict melting efficiency as it relates to process variables/121-s

Visualization of Marangoni Convection in Simulated Weld Pools C. Limmaneevichitr and S. Kou A way of evaluating Marangoni convection in a weld pool was devised by substituting the arc with a laser beam defocused to the size of an arc/126-s

AWS Web site: http://www.aws.org

M o n t h l y C o l u m n s ~

Press-Time News . . . . . . . . . . . . . . 9

Washington Watchword . . . . . . . . 11

Editorial . . . . . . . . . . . . . . . . . . . . 12

Commentary . . . . . . . . . . . . . . . . . 14

CyberNotes . . . . . . . . . . . . . . . . . . 16

Conferences . . . . . . . . . . . . . . . . . 18

News of the Industry . . . . . . . . . . . 20

New Products . . . . . . . . . . . . . . . . 26

Welding W o r k b o o k . . . . . . . . . . . 49

Coming Events . . . . . . . . . . . . . . . 51

Society News . . . . . . . . . . . . . . . . . 55

Guide to AWS Services . . . . . . . . . 72

New Literature . . . . . . . . . . . . . . . 74

Brazing Q&A . . . . . . . . . . . . . . . . . 77

Stainless Q&A . . . . . . . . . . . . . . . . 78

Navy Joining Center . . . . . . . . . . . 80

Personne l . . . . . . . . . . . . . . . . . . . 81

Advertiser Index . . . . . . . . . . . . . . 82

Classifieds . . . . . . . . . . . . . . . . . . 83

Welding Journal (ISSN 0043-2296) is the official monthly publication of the American Welding So- ciety. Editorial and advertising offices are located at 550 N.W. LeJeune Rd., Miami, FL 33126; telephone (305) 443-9353. Printed by R. R. Donnelley & Sons Co., Senatobia, Miss. Subscriptions: $90.00 per year in the United States and possessions, foreign countries $130.00. Single copies: members $6.00, nonmembers $8.00. Periodicals postage paid at Miami, Fla., and additional mailing offices. POSTMASTER: Send address corrections to Welding Journal, 550 N.W. LeJeune Rd., Miami, FL 33126. Starred (*) items excluded from copyright. Readers of the Welding Journal may make copies of articles for personal, archival, educational or research purposes, and which are not for sale or resale. Permission is granted to quote from articles, provided customary acknowledgment of authors and sources is made.

W E L D I N G J O U R N A L I 5

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P r e s s - T i m e N e w s

Progress Rail Services to Operate CPR Maintenance Shops

Progress Rail Services Corp., Albertville, Ala., and Canadian Pacific Railway (CPR), Calgary, Alberta, Canada, recently reached an agreement for Progress Rail to acquire and operate a major portion of CPR's maintenance and repair services at its Weston facilities in Winnipeg. Progress Rail will lease and operate CPR's metal fabrication, track work and wheel shops in Winnipeg, along with associated material handling and warehousing.

The agreement does not involve locomotive repair and maintenance facilities, the running car repair shop and the signal and communications equipment warehouse at the Weston facility.

The 45 supervisory staff members at the facility have become employees of Progress Rail. The 345 unionized shop workers will remain employees of CPR, but will be managed by Progress Rail.

Progress Rail is one of North America's leading suppliers of railroad and transit materials and services, including track work components, rail and rail welding, new and reconditioned freight car and locomotive parts, railcar and locomotive repair and leasing, track maintenance equipment and signal devices. It has facilities in 22 states, Mexico and Canada.

CPR provides rail and intermodal freight transportation services over a 14,400-mile-long network from Montr6al to Vancouver and throughout the U.S. Midwest and Northeast.

BOC Wins Contract to Manage Gas Supply at Detyens Shipyard

BOC Gases, Murray Hill, N.J., was recently awarded a seven-year contract to supply bulk and cylinder gases and manage the storeroom operations at Detyens Shipyard in North Charleston, S.C. The contract is valued at about $1 million annually.

BOC will manage a storeroom for welding, welding safety, abrasives and small tools. "We're looking to BOC to streamline what has tradition- ally been a cumbersome procurement and storeroom system that often did not have products available when we needed them, as well as improve our efficiencies in the structural and pipe divisions," Richard Stokes, Detyens' vice president of Operations, said.

International Forum on Construction Safety Scheduled

The International Division of the American Society of Safety Engineers (ASSE) and the British Institution of Occupational Safety and Health have scheduled their first-ever joint international safety forum for October 12 in London. The forum will focus on contractor/construction safety.

"As construction is on the rise throughout the world, contractor safety is a major international concern for safety and health professionals in the global manufacturing, service and construction sectors," said Kathy Seabrook, ASSE vice president of practices and standards.

The forum, which is sponsored by the global construction firm Black and Veatch, will be held at its U.K. Isleworth offices in London. The maximum attendance is 75. Reservations can be faxed to Laura Andujar at ASSE at (847) 296-3769 or by e-mail to [email protected].

Newport News Shipbuilding Appoints Board Member

Newport News Shipbuilding, Newport News, Va., recently announced Dr. Shirley Ann Jackson will join its board of directors beginning July 1. Jackson is the president of Rensselaer Polytechnic Institute in Tro3~ N.Y. She served as chairman of the U.S. Nuclear Regulatory Commission from 1995 to 1999. Prior to that, she was professor of physics at Rutgers University in New Brunswick, N.J., while also serving as a consultant in semiconductor theory to AT&T Bell Laboratories.

Newport News Shipbuilding designs and con- structs nuclear-powered aircraft carriers and submarines for the U.S. Navy and provides life- cycle services for ships in the Navy fleet.

Profax/Lenco Purchases Electrode Holder Manufacturer

Profax/NLC Lenco has purchased the assets of Duro Engineering Co., a manufacturer of electrode holders and replacement parts. The company has been moved from East Hamden, Conn., to Lenco's manufacturing plant in Jackson, Mo.

Products are now ready for shipping and will be marketed through welding supply distributors.

WELDING JOURNAL 19

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W A S H I N G T O N W A T C H W O R D BY HUGH K. WEBSTER ~ _

AWS Washington Government Affairs Office

Hearings Held on Voluntary Consensus Standards

The Technology Subcommittee of the House Commit- tee on Science held hearings in March regarding compliance of federal agencies with the National Technology Transfer and Advancement Act of 1996. This legislation was designed to encourage federal agencies to adopt technical and product standards as developed by private consensus bodies, replacing government-developed standards. Wit- nesses from the Department of Defense (DOD), Department of Energy, the General Accounting Office and the National Institute of Standards and Technology testified.

It was clear compliance by federal agencies with this legislation has been inconsistent at best. In addition, the participation of federal employees in the voluntary consensus standard process, which the legislation was also designed to encourage, has actually decreased. For example, according to testimony, in 1994 approximately 2200 De- partment of Defense personnel participated on voluntary standards committees. Today, that number has dropped to just over 400 people. This decrease has been attributed to a variety of causes, including downsizing of technical personnel at DOD, reduced budgets and the fact money for attending committee meetings is one of the early and easy targets of budget cuts.

Pipeline Safety Legislation Introduced

Companion bills have been introduced in both houses of Congress to enhance pipeline safety. The legislation could significantly increase inspection requirements for pipelines, in particular those with a history of leaks. It would also require pipeline operators to be certified by the Department of Transportation and tested on a regular basis with respect to qualifications. Further, the results of pipeline tests and inspections would be made available to the public, and a nationwide map of all pipeline locations would be placed on the Internet. Finally, the legislation would mandate a number of studies on various technologies that may improve safety, such as external leak detection systems and double-walled pipelines.

Both bills are partially a result of a pipeline accident last year in Washington State in which three persons were killed. The entire Congressional delegation from Washington has signed on as cosponsors.

Electronic Commerce Commission to Provide Final Report

A "day of reckoning" may be close at hand for the Fed- eral Advisory Commission on Electronic Commerce. Congress established this Commission to develop strategies for addressing the controversial issue of Internet taxes. The Commission is supposed to provide its final report to

Congress sometime this spring. There is speculation the Commission may endorse an extension of the current mora- torium on Internet taxes, but also offer means of allowing states to collect sales and use taxes in the future.

Ergonomics Hearings Begin

The Occupational Safety and Health Administration (OSHA) has begun hearings on its controversial ergonomics standard. These are the first in a series of hearings OSHA plans to sponsor over a nine-week period. Those testifying will represent most of the affected interest groups, particularly industry and labor. Witnesses and OSHA representatives will address issues such as economic feasibility of the proposed standard and the challenges of compliance. Over- all, OSHA is expected to hear from 650 witnesses. The agency has already received more than 7000 written com- ments.

The hearings are intended to elicit information to assist OSHA in finalizing the rule. Whether or not particular witnesses think there should be a rule at all is not relevant to OSHA. Its decision to issue a rule is already final.

Skilled Foreign Workers Legislation Progresses

Legislation continues to progress in Congress that would sharply boost the number of highly skilled foreign workers allowed into the United States. Specifically, the legislation would allow 195,000 H-1B visas to be issued each year for the next three years. Just two years ago, Congress raised the annual ceiling on these visas from 65,000 to 115,000, which is the current maximum. This is scheduled to decrease to 107,500 in 2001, then 65,000 subsequently. Many businesses, however, particularly in the technology area, have complained the current allotment of H-1B visas is insuffi- cient. And, in fact, all available visas over the past several years were issued before the end of each fiscal year.

Exporter Database Created

The U.S. Small Business Administration has created a new service, Trade Mission Online. This is a database of U.S. small businesses that seek to export their products. TM Online is also a search engine for foreign firms and U.S. businesses seeking a U.S. business partner or supplier, through such means as direct product sales, licensing or franchising agreements. TM Online can be accessed at www.sba.gov/tmonline.

Contact the AW$ Washington Government Affairs Office at 1747 Pennsylvania Ave. N.W., Washington, DC 20006; telephone (202) 466-2976; FAX (202) 835-0243.

WELDING JOURNAL I 11

E D I T O R I A L

Our Common Coal: A Sk, lled Labor Force

Global economy. One marketplace. Wor ldwide shortage of skilled labor. These phrases have become the mantras of today's business world and, regardless of borders and languages, they represent issues that are being felt the world over. And while it's true the economy has been booming, it's not always pre- dictable. We've witnessed the stock market take some wild rides, undulating in reaction to trend indicators affected by many factors. We all must learn to adapt to today's constantly changing business culture. The companies that do are adding great value to their operations and enhancing their ability to succeed.

The welding industry- - both the companies that manufacture welding equipment and consumables and those that use those products to manufacture other goods - - is not isolated from the changes taking place in business today. Our industry has already experienced a number of consolidations between competitors both large and small. We are just starting to experience the Internet's ability to make "shopping" a simple click away - - making direct customer contact a pre- cious commodity. And every research report indicates skilled labor is in high demand but availability of those skilled workers is scarce.

I've had a unique opportunity this past year to gain insight into the needs of the welding industry both in the United States and abroad. As this year's AWS President, I've had the privilege of representing the members of the American Welding Society during my travels to various countries, as well as to a large number of domestic Sections. My goal has been to continually spread the word on the importance of education and training. Every stop I've made during the past twelve months has resulted in the same conclusion: the need for a worldwide education and training program for welders, engineers and inspectors that is AWS endorsed.

But AWS isn't just talking about what needs to be done, it's working at every opportunity to meet the needs of its constituency. AWS has more than 50,000 members, of whom approximately 20,000 are certified personnel. Domestically, AWS is working very hard to meet the needs of the fabrication and construction industries, where welding is absolutely essential. The Society's launched new programs tai Iored specffical ly for Certified Welding Inspectors and offered more training opportunities in more cities (as well as in cyberspace). AWS volunteers and staff have also continued working toward having all 50 states adopt the S.E.N.S.E. curricula, which encompasses the Entry Level, Advanced Level and Expert Level Welder programs. Internationally, we are working with many counterpart orga- nizations and their governments in an attempt to have AWS's education and training programs recognized in those countries. This is not an easy undertaking, especially in the area of translation of training materials.

The good news is that everyone is working toward the same goal: a skilled labor force. This is the common thread that ties everyone in the international welding industry together. AWS is playing an enormous role in reaching this goal. You can be assured that our Society, and its highly respected programs, are attaining global acceptance. We are reaching all corners of the world.

This past year as President has been rewarding and educational. I have obtained unique insights that wil l aid me in my continuing role as chair of the AWS Education Committee. I am confident AWS will meet the challenges of our industry. I would like to thank the Society for supporting my presidency and giving me the opportunities that have allowed me to gain these valuable insights.

Robert J. Teuscher A WS President

AMERICAN WELDING SOCIETY

O f f i c e r s

President-- R. J. Teuscher Airgas, Inc.

Vice President - - L. W. Myers Dresser-Rend. Inc., Olean Operations

Vice President - - R. L Arn Glunt Industries

Vice President - - E. D. Levert Lockheed Martin Missiles and Fire Conbot

Treasurer- A. O. Winsand consultant

Executive Director - - F. G. DeLaurier, CAE

D i r e c t o r s

J. M. Appledorn (Dist. 18), The Linco~ Elect,c Co. B. J, Bastian (At Large), Benmar Assoc~es H. J. Bax (Dist. 14), tee Kay Sup~j M. D. Bell (Dist. 221, Preven~ve Metal~rgy H. E. Bennett (Dist. 8), Bennett ~es Co. B. A. Bernstein (Dist. 5), Techn~Veld Lab S. W. Bollinger (Past President), ES~ WeU~g&Cut~ngPn D. F. Bovie (At Large), ESAB WeU~¢ & Cut~g Products C. F. Burg (Dist. 16), Ames Laboratory S. C. Chapple (Dist. 11), Midway Products Group G. R. Crawmer (Dist. 6), GE Power Generation Eng~eer~ A. F. Fleury (Dist. 2), ~ F. Reury & Assoc~es J. R. Franklin (At Large), Sen~om Mfg Co. L. C. Heckendorn (Dist. 7), ~tech R&D, USA J. D. Heikkinen (Dist. 15), S~rtan sauna Heaters, ~c. J. L. Hunter (Dist. 13), M~su~ Motor Mfg. of America, Jnc C. B. Kaufman (Dist. 3), Dresset Welding Supply R. D. Kelium (Dist. 19), Wi, amette Wading Sup~ Co. M. D. Kersey (Dist. 12), The Linco~ Elec~c Co. N. R. Kirsch (Dist. 20), St~ng correctional Facility D. J. Kotecki (At Large), The Unco~ E~ctr~ Co. R. C. Lanier (Dist. 4), Pitt community Co~ge V. Y. Matt~ews (Dist. 10), The L~co~ Bectric Co. T. M. Mustateski (At Large), Lockheed MarUn Energy Syst~ R. C. Pierce (Past President), w e ~ Engineering Supply G. H. Putnam (Dist. 1), Thermal Dyna~cs O. P. Reich (Dist. 17), Texas State Techr~al Co~ge atWac F. R. Schneider (Dist. 21), Bob Schne~er Consu~ng Servk

T. A. Siewert (At Large), NIST O. J. Templet(Dist. 9), Tem~etNTemp~t We~ngSuppb

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Joining the Digital Revolution When I started in the magazine publishing business, more than 30 years ago,

I thought the existing printing technology was pretty slick. I worked for Welding Engineer magazine then, and the first time I visited our printer in central Illinois, the clattering Linotype typesetters and the huge sheet-fed presses made a lasting impression. I left feeling a little dazed by the acrid odors of ink and molten type, and by the strange printer's jargon that had permeated our conversation. This was in the heyday of letterpress printing, which involved such rudimentary press elements as standing type and etched copper halftones mounted on cherrywood blocks. What seemed high-tech to me at the time was, by today's standards, like something out of a Flintstones cartoon.

Over the years, magazine production technology evolved into something that really was pretty sophisticated. Four-color web offset printing replaced letterpress, and print plates produced from film negatives delivered type and images that were much sharper and truer on the page.

Then, just about ten years ago, desktop publishing began to revolutionize the editorial and design aspects of magazine production. With desktop, you could manipulate illustrations and type with ease, and add jazzy graphic elements such as gradient color screens, three-dimensional shadowing and enhanced photos. Plus, you could throw those blue editor's pencils and jars of rubber cement out the window since every task was accomplished directly on your computer screen. Using desktop technology, all kinds of magazines took on a more colorful and generally more professional appearance. The Welding Journal certainly did, and by 1993 it was a far more graphically complex and attractive magazine than ever before.

Well, now we have the opportunity to experience another major revolution in printing. Called computer-to-plate (CTP) printing, this new process places magazine pages in digital format and eliminates the use of film entirely. The American Welder supplement mailed with this issue of the Welding Journal is our first foray into filmless printing. In June, the Welding Journal itself wil l go digital, and our other magazine, Inspection Trends, will take the same route in July.

What wil l CTP printing offer to you, the reader? You should notice that type and drawings in the magazine are sharper, for one thing, and the color photog- raphy brighter and richer. In addition, eliminating our normal film production step saves time, both at our end and at the printer. This means we have a better chance of squeezing last-minute news items into the current issue instead of having to wait until the next issue to publish them. It's a good deal, all around.

I'll admit I tend to be a little obdurate when faced with big-time changes in my routine, but not this time. Digital printing is clearly the wave of the future and, if it means bringing you a better product, we'l l go for it without hesita- tion. Good reading.

Jeff Weber Publisher, Welding Journal

14 [ MAY 2000

WELDING JOURNAL Editorial Staff Publisher

Jeff Weber Editor

Andrew Cullison Features Editor

Mary Ruth Johnsen Managing Editor

Christine Tarafa Assistant Editors

Susan Campbell Tim Heston

Production Coordinator Zaida Chavez

Peer Review Coordinator Doreen Kubish

Contributing Editor Bob Irving

Publications, Expositions, Marketing Committee G. D. Uttrachi T.C. Myers Committee Chairman Do~Tech Ltd. ESAB Welding & Cut~ng

G. M. Naay G. O. Wilcox Consultant Vice Chairman Thermedyne Industries

N. Zapata Secretary American Welding Society P. Albert Krautkramer Branson

R. L. Arn Glunt indust~ T. A. Barry Miller Elecbic Mfg. Co. C. E. Boyer AB8 Robotics

T. C. Conard ABICOR Bmzel

D. L. Doench Hobart Brothers Co.

J. R. Franklin Sellsb'om Mfg. Co.

N. R. HeRon Pandjiris, Inc.

V. Y. Matthews The Uncoin Electric Co,

Advertising Director of Sales

Rob Saltzstein Advertising Sales Representatives

Blake and Michelle Holton 1-800644-5563

Advertising ProducUon Manager Colleen Beem

Subscriptions Nancy Batista

American Weldinlt Society 550 N.W. LeJeuneRd., Miami, FL 33126 (800) 443-9353 Colpyright @ 2000 by .4met'l¢~ Weklb~ Soch~. "t~e Sed- ety is not responsible for any statement made or op~on e~- pressed herein. Data and informalion developed by b~e aulhers of specific articles are for informational purposes anly a~l am ont intended for use without independent, substan'da~ng inves~atiae on the part of poton~al users.

R.G. Pali J, P. Nissen Co.

S. Roberts Whibtey Punch Press J. F. Seenger, Jr. Edison Welding

R.D. Smith 1tle Lincdin Elecbic Co. P. D. W'mslow, Ex Off. Hyper~em E. D. LeverL Ex Off. Lockheed Martin Missiles and Fire Cobol

L. G. Kvidahl, Ex Off. inpgs Shipbuilding

A. O. V~nsand, Ex Off. Consultant

R. J. Teuscher, Ex Off. /~rgas

F. G. DeLaurier, CAE, Ex Off. Amedc~ W ~ Sock~y

Ho flakes! Copper coating on weld wire

can flake and clog gun liners and tips. Flakes cause reduced arc time

due to feedability problems that increase cleaning and repairs, elevate consumables costs and

reduce tip and liner life.

N-S CopperFree" wire runs better - no flakes.

N-S CopperFree" carbon steel

wire has no copper coating (and no flakes) so you get more productive

welding time. A unique lubricant

coating reduces N-S CopperFree" wire's feed force by up to 75% compared to copper-coated wire. That superior feedability increases arc time and operator control. You get more welds, and more consistent

welds. And no flakes.

N-S CopperFree" wire resists rust and oxidation as well as

copper-coated wires, but having no copper coating it minimizes toxic

copper fumes.

._QS-aOOO.

See for yourself. Get a FREE spool of N-S CopperFree wire.

Try N-S CopperFree ° carbon steel wire to see its great feedability, without copper flaking. Call your National Standard Distributor to arrange a free, no obligation

demonstration on your own equipment. You have nothing to

lose but your flakes.

Welding wire to robotic standards

© National-Standard W e l d i n g P r o d u c t s D i v i s i o n

Niles, Michigan Ph. 800-777-1618 Fax: 616-683-9276

www.nationalstandard.com

Circle No. 26 on Reader Info-Card

CyberNotes A col lect ion o f indust ry n e w s f rom the In ternet

BY MARY RUTH JOHNSEN, Features Editor

On-Line Robotics Information

Robotics Industries Association. This site offers plenty of information regarding the Robotics Industries Association (RIA), a robotics trade association based in Ann Arbor, Mich., and its member companies. The site offers an industry directory, membership information, a book store offering the association's standards, and a calendar of events that includes the organization's trade shows, workshops and conferences. Visitors interested in working in the robotics industry can check out the Jobs section, which posts openings from a variety of companies.

The site also features a lengthy offering of case studies, which are listed by application and by industry. Some of the industries listed are automotive, fabricated metals, off-road/ heavy equipment, electronics and consumer goods/appliances. Indus- try statistics and other articles are also included.

In an article titled The Robotics Industry: Leading the Change to a Productive 21st Century, RIA Execu- tive Vice President Donald A. Vincent details the history of robotics in North America. According to the article, "From 1992-1997, North American robotics companies posted gains in new orders of 131%. A total of 12,149 robots valued at over $1.1 billion were ordered in 1997, a new record. Shipments also topped $1 billion for the first time, making 1997 the industry's biggest year ever. While orders grew just 1% in 1997, the industry capped a string of great years, having grown 31% in 1992, 29% in 1993, 19% in 1994, 18% in 1995 and 25% in 1996. In 1998, the industry again topped $1 billion, although orders were down 10% over 1997. Due to the Asian crisis and global financial turmoil, many manufacturing companies either cut back on or postponed their robotics in- vestments."

http://www.robotics.org

Site Adds New Features

The Lincoln Electric Co. The welding equipment company recently revamped its site by adding new features such as a site-wide search engine and an updated distributor Iocator and making it easier to navigate.

New product information can be accessed directly from the home page. The home page also contains a calendar of events and a Latest News section that includes a brief synopsis of articles and other items. Browsers click on a link to

access the full text; they can also request the company's on-line newsletter be e-mailed to them. A recent offering was How to Strike and Establish an Arc, which offered tips on the scratching and tapping methods of striking an arc for shielded metal arc welding. According to the article, "The principle difficulty encountered in striking the arc is 'freezing,' or when the electrode sticks or fuses to the work. This is caused by the current melting the electrode tip and stick- ing it to the cold base metal before it is withdrawn from contact. The extra high current drawn by the 'short circuit' will soon overheat an electrode and melt it or the flux, unless the circuit is broken. Giving the electrode holder a quick snap backward from the direction of travel will generally free the electrode. If it does not, it will be necessary to open the circuit by releasing the electrode from the holder."

The Products section includes a Products

Navigation Guide by product category and a Tech Topics Library of technical information. Visitors to the site use scroll-down menus to access articles in a variety of categories, including welding/cutting processes and theory, application stories and how-to welding tips.

http://www.lincolnelectric.com

Metal Fabrication News

Nooter Corp. This site offers information on each of the 13 companies that

make up the corporation, which is based in St. Louis, Mo., and the services they provide. These services include fabrication, field construction, heat recovery and thermal spray.

The ASME Guide- lines section illustrates some of the types of pressure vessel construction provided under Section VIII, Di- vision 1 of the ASME Boiler and Pressure Ves- sel Code and gives references to the applicable rule in the Code. There is an on-line version of the guide that can also be down- loaded. The same holds

true for Nooter Units, a software program designed to aid engineers in converting metric units to Imperial units. The program allows users to convert any dimen- sion or thermal measurement into a compatible u n it of measurement. Step-by-step instructions are provided for visitors who decide to download the software.

http://www.nooter.com

Steel Rule Dies and Bending Equipment

J. A. Richards Co. The site for this Kala- mazoo, Mich.-based company offers product information about the company's line of steel rule dies, steel rule diemak- ing equipment, steel rule stamping dies and rotary, utility and ram benders.

http://www.jarichards.com

1 6 1 M A Y 2000

lEO 9001 CERTIF IED • UL LISTED PRODUCTS

DUR MAIN EMPHASIS IS ON VALUE

HE BEST WARRANTY IN THE BUSINESS

BROAD PRODUCT SELECTION

Ii

GENERICO products are produced, assembled, and tested by an exper ienced and dedicated work force that is commi t ted to the highest standards of product integrity and excel lence consistent wi th our ISO 9001 cert i f ication and UL l isted products.

THE HIGHEST QUALITY AT THE LOW PRICES! Quality and pdce must speak for themselves, so we encourage your inquiry. See for yourself why - the wor ld over - more and more professionals are using G£NERICO products.

TWO YEAR "OVER THE COUNTER REPLACEMENT" WARRANTY All GENERICO manufactured welding apparatus and equipment is warranted to be free from defect ive material and workmanship for a per iod of t w o years from the date of purchase.

Regulators • Single Stage • Two-Stage • Station • Line • Manifold • Flowmeter & Flow Gauge • Piston • Balloon

Welding Apparatus • Torch Handles • Cutting Attachments • Cutting Torches • Machine Torches • Air Torches • Welding & Heating Nozzles • Cutting Tips • Flashback Arrestors • Check Valves

Welding Accessories • Electrode Holders • Ground Clamps • Cable Connectors,

Lugs & Splicers • Chipping Hammers • Magnetic Holders • Tip Cleaners & Ddlls • Spark Lighter • Welding Goggles

G E N S T A R T E C H N O L O G I E S CO. , INC . PRODUCTS ALSO AVAILABLE FROM 4525 Edison Ave • Chino, CA 91710 THE FOLLOWING WHOLESALERS: Tel: (909) 606-2726 • Fax: (909) 606-6485 . United American Sales, lnc.(U.A.S.)Wilmington, OH 800-421-7081

• Westgate Sales Corp., Oakland, NJ 201-337-0024 Websi te : www.gens ta r t ech . com . Doyle's Supply, Inc., Decatur. AL 800633-3959

~ Circle No. 16 on Reader Info-Clrd

"'Pros W h o K n o w . . . Go G £ N £ R I C O "'

A WS Conferences & Seminars

AWS D1.1 CODE WEEK

The #1 selling welding code now comes alive in a five-day seminar that begins with a roadmap of DI. 1:2000, Structural Welding Code - 5reel. This is your opportunity to learn from an expert AWS instructor and ask your toughest questions about D1.1.

Code week continues with corresponding subjects geared to engineers, supervisors, planners, welding inspectors and welding technicians. Since your work is based on a reputation for reliability and safety, you want the latest industry consensus on prequalification. If you want to improve your competitive position by referencing the latest workmanship standards, inspection procedures and acceptance criteria, you won't want to miss this seminar! Each day will be in depth and intense.

(Day 1, Monday) DI.1 Road Map Las Vegas, Nev. - - May 22 Chicago, III. - - June 5 Philadelphia, Pa.--July 10 Detroit, Mich.-- August 21

(Day 2, Tuesday) Design of Welded Connections Las Vegas, Nev. - - May 23 Chicago, IlL - - June 6 Philadelphia, Pa.--July 11 Detroit, Mich.--August 22

(Day 3, Wednesday) Qualifications Las Vegas, Nev. ~ May 24 Chicago, III. - - June 7 Philadelphia, Pa. m July 12 Detroit, Mich. - - August 23

2000 SCHEDULE

(Day 4,Thursday) Fabrication Las Vegas, Nev. -- May 25 Chicago, III. - - June 8 Philadelphia, Pa. - - July 13 Detroit, Mich.-- August 24

(Day 5, Friday) Inspection Las Vegas, Nev. -- May 26 Philadelphia, Pa. -- July 14

Chicago, III. - - June 9 Detroit, Mich. m August 25

Prices Member Nonmember

(One-day seminar) $345 $420 (Entire Week) $795 $870

U P C O M I N G C O N F E R E N C E S

B A S I C C R A C K I N G P R O B L E M S A N D

S O L U T I O N S C O N F E R E N C E

July 20±21 m Milwaukee, Wis. Hydrogen-induced cracking isn't the only culprit that engineers and QC professionals need to be on the alert against. AWS experts will identify other, often unknown or overlooked, cracking scenarios, along with the best use of counteroffensives, including preheat and peening, and the best use of ultrasonics and Charpy, plus the lowdown on new test options. This intense day-and-a-half program covers cracking in steels, aluminum, stainless steels and titanium.

A W S / D V S C O N F E R E N C E A N D E X H I B I T I O N

O N P L A S T I C W E L D I N G

October 24-25 - - Orlando, Fla. This two-day event will feature presentations within each of the five scheduled sessions listed below: • Welding Methods, Welding Machines and Equipment • Testing of Welded Joints, Design Calculations for Containers

and Apparatus, Characteristic Values • Welding of Thermoplastics in Manufacturing • Education and Qualification of Welders elnvestigations into the Latest Research in Pipe Welding

H O W T O C O M P E T I T I V E L Y W E L D T H E

21st C E N T U R Y S H I P

November 8 - 1 0 m N o r f o l k , Va. This three-day event will feature presentations on one-sided, single-pass, multiwire SAW, two-wire GMAW and plate cutting technologies; plasma vs. laser vs. water jet; robotic welding; panel line fitting; and welding automation; laser butt-joint welding; weldable primers; line heating technology; laser mapping for accuracy control; low-carbon bainitic electrodes; carbon equivalent; double-sided arc welding; and more.

I C A W T 2 0 0 0 (GAS M E T A L A R C W E L D I N G

FOR THE 21ST C E N T U R Y

December 6-8 m Orlando, Fla. This is a landmark conference on the gas metal arc welding (GMAW) process and the related flux cored arc welding (FCAW) process, celebrating 50 years of GMAW and evaluating ways in which the application of the latest developments in GMAW technology can assist users in increasing productivity and quality. International experts will give keynote papers, and the latest process developments will be discussed in five sessions over three days.

Contact the AWS Conference Department for additional information at (800) 443-9353 ext. 223 or (305) 443-9353, I ext. 223. I 18 I MAY 2000

0

1. Superior Surface Tension TransfeF"and pulsed MIG welding performance.

2. Synergic single knob control.

Power Wave 455/STT

F

3 . Trouble-free Ioadin~j and feeding from the sprit wire guide.

4 . Set-up flexibility with one control cable to connect all pieces.

5 • Modular design that changes easily from bench to boom.

L coln Electric: 7

6 . Easy upgrade from simple to sophisticated control.

7. 3-year warranty and the unmatched support of Lincoln Electric.

The Lincoln Electric Company, Cleveland, Ohio U.S.A.

O0~4AR

The Power Wave ® 455/STT ~ welder combines Lincoln Electric's exclusive Power Wave and STT technologies in an easy-to-operate unit that can change to nearly any kind of MIG welding with just the flip of a switch. Ask your Lincoln distributor for a demonstration.

LINCOLNB B ELECTRIC

888/355-3213 www.lincolnelectric.com The Welding Experts

Circle No. 2 3 on Reader Info-Card

News of the Industry'

Miller Starts Two-Year Street Rod Project

The Miller Electric Mfg. Co., Appleton, Wis., will kick off a two-year-long project that wil l culminate in the construction of a fully refurbished 1931 Ford coup~ street rod at the Street Rod National South show in Knoxville, Tenn., from May 5-7.

The street rod project wil l travel to five shows this year and five more in 2001. During the project, the company wil l conduct a series of hands-on seminars and demonstrations that wil l give attendees a step-by-step look at the processes involved in the car's construction. Topics wil l include frame building, patch panel installation and engine construction.

During the first show in Knoxville, Miller district managers

Wayne Reece and Jim Nye wil l offer two seminars each day at 10 a.m. and 2 p.m. The two-hour-long sessions wil l include demonstrations of plasma arc cutting machines and gas metal arc welding power sources. Frame building wil l be the topic covered.

The frame wil l be completed and installation of the patch panels wil l begin at the next scheduled stop, which is the Street Rod Nationals in Louisville, Ky., on August 3-6. Future stops for this year are tentatively slated for the Good Guys 12th Hot Rod Nationals, Indianapolis, Ind., June 9-12; the Frog Follies, Evansville, Ind., August 25-27; and the Good Guys 7th South- eastern PPG Nationals, Charlotte, N.C., October 20-22. For more information about the Street Rod Project, contact Wayne Reece at (502) 239-4488.

At the Street Rod National South show, Mil ler district managers Wayne Reece and Jim Nye wi l l start building the frame to re- furbish a 1931 Ford coup~ street rod. Here, Reece welds on the rear-end housing to install a four-bar system.

Materials Science's Steel Composite To Be Used in Automotive Body Panels

The Ford Motor Co. recently chose the Quiet Steel® composite material from Materials Science Corp. (MSC), Elk Grove Village, II1., for use on the dash panel for the 2001 Explorer Sport Trac sport utility vehicle. The material was designed to reduce noise and vibration.

Quiet Steel is a 0.001-in.-thick polymeric coating sand- wiched between two metal skins. The metal skins can be customized to design engineers' specifications for type and thickness, and the polymeric coating can be tailored to meet specific noise reduction needs. The material is 100% recyclable and is manufactured in a high-speed continuous coil. It can be delivered in sizes up to 72 in. wide and weights up to 50,000 lb. It can be processed in standard transfer press equipment. It is available through the company's MSC Laminates and Compos- ites subsidiary.

Industry Notes

• PRC LASER recently added welding capabilities to its laser applications laboratory and demonstration facility at its headquarters in Landing, N.J. The facility houses a range of the company's CO2 lasers ranging from 1 to 6 kW, as well as products currently in research and development stages. The addition to the lab is designed to support end users in inte- grating lasers into their manufacturing processes.

• Houghton International Inc., Valley Forge, Pa., has split its Metalworking Products and Chemical Management Ser- vices into two separate divisions led by their own presidents and also acquired Bencyn, Inc., Lafayette, Ind., which spe- cializes in the management of metalworking and specialty chemical fluid processes. William J. Pearcy, now president of Houghton Metalworking, will focus efforts on developing and marketing the company's chemical products for metalworking processes, as well as expanding its product line. The company produces a line of specialty chemicals, oils and lubricants for industrial processing, including heat treating, die casting, cutting and grinding and offshore oil exploration and production. John Brenan, now president of Houghton FLUIDCARE®, wil l develop programs to enhance production processes and improve the successful control of fluids impacting production.

• Hypertherm, Inc., Hanover, N.H., recently changed the name of Centricut Automation to Hypertherm Automation. Hypertherm purchased Centricut LLC, Lebanon, N.H., a maker of PC-based CNC controls for thermal cutting machines, in the fall of 1999.

• The Edison Welding Institute (EWl) and The Ohio State University recently signed a new intellectual property agreement that defines ownership and licensing rights between the two organ izations, thereby allowing for greater collaboration in the field of materials joining as well as related academic disciplines at Ohio State. Currently, EWl spends approximately $3 mill ion a year in materials joining research, of which about $750,000 is spent with Ohio State. Intellectual property developed at Ohio State with EWl support wil l be marketed to EWI's 400 customers.

• Construction crews recently erected a symmetrically adorned, two-story casino in the U.S. Virgin Islands with structural steel designed and fabricated by Steel Fabricators L.L.C., Ft. Lauderdale, Fla. More than 540,000 Ib of steel, including 110,000 Ib of reinforced steel, were used in the casino. The 75,000-sq-ft casino is part of the Divi Carina Bay Resort on the east end of St. Croix. The $15 million hotel has 126 rooms and 20 villas. The casino features a raised glass ro- tunda with a brass skin over rolled tube steel, with column

20 I MAY 2000

Engineers from MSC and Ford closely collaborated to develop a dash system that met the goals necessary to the vehicle's overall development: noise reduction, weight reduction and cost savings. Previously, the dash was made of four components with an overall weight of 27 Ib: a dash insulator, steel dash doubler, mastic deadener and steel dash panel and engine side fiberglass dash insulator. The new system weighs 20 Ib and consists of a Quiet Steel dash panel and fiberglass dash insulators.

Piranha Completes First Phase of Building Expansion

Piranha, Hutchinson, Kan., recently completed the first phase of a planned three-phase plant expansion. Phase one includes a 72,000-sq-ft facility that houses a new paint system and a 100,000-1b overhead crane lifting capacity. Most of the company's line of press brakes and shears are manufactured at the new facility.

Piranha, a division of Mega Manufacturing, recently opened a 72,000-sq-ft expansion of its facility in Hutchinson, Kan.

covers designed to resemble granite. The steel framework for the structure is exposed and visible from inside and outside the casino.

Jetline Engineering, Inc., Irvine, Calif., and AMET Inc., Rexburg, Idaho, recently announced the formation of a technological alliance. Jetline with provide hard automation fixturing and controls and AMET will provide computer controls and software. Working together, Jetline and AMET engineers will provide fully compatible systems with coor- dinated support facilities.

41) Arcos Alloys, Mt. Carmel, Pa., recently became Arcos Alloys Corp., a subsidiary of Armada Corp., Detroit, Mich. Since 1983, the company had been operating as a division of Hoskins Manufacturing Co., Detroit. Armada is the par- ent company of both Arcos and Hoskins. According to Ar- mada President Jerry Reinke, the purpose of the change was to give more recognition and independence to the Arcos Alloys business unit. Arcos is a supplier of welding electrodes and wire. James Breen has been named president of Arcos Alloys Corp. Since 1986, he had served as managing director of Hoskins Alloys Ireland, Ltd. Rick Laubach has been named vice president. He has served in a number of capacities at Arcos, most recently as marketing manager.

Powerful Solutions ForWelding And Cutting Automation

Precision Cutting Automation

Bug-O Systems has been showing manufacturers how to automate their welding applications for more than 50 years. We would be happy to discuss any applications you have in mind.

If you have any questions or applications you'd like to discuss, call 1-800-245-3186 ext. 55.

0 Bug-O Systems

3001 West Carson Street Pittsburgh, PA USA15204-1899 Phone: 1-412-331-1776 Fax: 1-412-331-0383

http://www.bugo.com <~< ( E

Circle No, 6 on Reader Info-Card

manent markson metal, w~ood, plastic, glass, cardboard, etc. They write on any surface: rough or smooth, wet or oily; even marks underwater.

The plastic case prevents the paint from drying out so it always writes easily and smoothly. The case also allows you to use the entire stick without needing a separate holder.

The markers are available in two sizes: Standard and ]umbo and four fast-dDing, lead-free colors: white, vellov,', red and black.



DOES YOUR WELDING TRAINING

MEASURE UP TO INDUSTRY STANDARDS?

it, " "Ix ~ '~ '"

Put 70 years of world-class welding training experience from the Hobart Institute of Welding Technology ® to work for you.

• Complete curriculum materials on all major processes.

• Modular design.

• Close-up shots of the welding arc highlighting proper technique.

• Easy-to-foUow "how-to" student workbook design.

• Comprehensive instructor guides.

• Based on AWS S.E.N.S.E. objectives, with standard AWS terms and definitions used throughout.

• Welding software (Weld_IT °) for compelling presentations, custom handouts, procedure specifications, and more.

For more information call 800-332-9448, Ext. 5433

or visit www.welding,_o_~g

HOBART INSTITUT]~ OFWI~DINGTEOt~LOGY

World-Class Training from a World.Class Institution 0 ~ Hob~ ln~tutv Of Welding Technology

Circle No. 17 on Reader Info

22 I MAY 2000

The second phase wil l include a 32,000-sq-ft addition to the phase-one building. It wil l house CNC cutting and grinding equipment. It is expected to be completed by spring 2001. The third phase, a 56,000-sq-ft addition with overhead cranes and additional paint capacity, wil l house some of the machining and all of the assembly operations for the ironworker line of products. Projected completion is spring 2002.

Genesis Systems Group Wins Contract from American Axle

Genesis Systems Group, Davenport, Iowa, recently received a $15 million contract from American Axle Manufacturing to provide robotic welding systems for its manufacturing plants in Detroit and Hamtramck, Mich., Buffalo, N.Y., and Silao, Mexico.

The Versa-System 4M robotic welding and cutting work cells wil l be used to weld brackets to salisbury axles for sport utility vehicles and pickup trucks for General Motors. As many as five brackets are welded to a 30-in.-Iong, 4-in.-diameter steel tube. The weld cycle for a completed set of two tubes is 1 min.

American Axle manufactures, engineers and designs drive- line systems and forged products for trucks, buses, sport utility vehicles and passenger cars.

These Genesis Versa-System 4Ms will be used to weld brackets to axles for a variety of General Motors sports utility vehicles and pickup trucks.

Hudson Tool and Die Opens Technology Center

Hudson Tool and Die Co., Ormond Beach, Fla., recently opened a $1.2 million center designed to cut lead times for new tooling. The center houses new CNC machines, manual machines and other

Hudson Tool and Die's new technology center is now fully op- erational.

equipment to produce simple and complex tooling. Hudson manufactures precision deep-drawn enclosures

and high-speed precision stampings and assemblies. It designs and manufactures precision metal components for the automobile, medical, electrical and other industries.

Air Liquide Donates Equipment to College in British Columbia

Air Liquide Canada, Inc., recently donated two welding units worth $26,000 to the University College of the Fraser Val- ley (UCFV) in Abbotsford, British Columbia, Canada. The company will also provide supplies and maintenance for the equipment and upgrades as newer equipment becomes available.

Carl Heinrich, welding technical manager for Air Liquide,

ARONSON POSITIONERS

POSITIONING Made Easy

UCFV President Skip Bassford (left) presents Carl Heinrich and Stu Younger (right) of Air Liquide with a plaque honoring the company for its donation of $26,000 worthof equipment to the UCFV Welding Department.

said one of the company's goals is to increase the growth of manufacturing in British Columbia, and training welding students in the area on the newest equipment available is one way to do that. "We are working with industry and training institu- tions to make sure they get what they need. Industry tells us they want students who can go right to work when they graduate, and that's what we're endeavoring to provide," Heinrich said. "By training on the latest equipment, UCFV students will hit the road running when they graduate."

Cypress CB-1P Plasma Circle Burner Cypress Welding has been saving manufacturers time and money by making equipment that burns accurate holes for more than 25 years,

• CYPRESS WELDING EQUIPMENT, INC. P.O. BOX 690168 • HOUSTON, TEXAS 77269 PHONE: 1-261-469-0746 • FAX: 1-281-469-9354 www.cyypressweld.com (~


Now you can get Aronson positioning quality at a popular price. Koike Aronson engineered in the accuracy, safety and reliability you've come to expect, but at a lower cost. MD (met ric designed) two-a> positioners provide ~/ with full continuous bi-directional rotatio and 135 ° tilt from horizontal. And, they're rated for full-load, non-stop u,,

• 4 models to choo'~ . . . . . . . • 1000 to 5000 kg capacities • solid state variable speed rotation; dynamic braking • anti-friction bearings for greater life and efficiency

Your Koike Aronson distributor has all the details.

- ~ KOIKE ARONSON 635 West Main Street Arcade, NY 14009


WELDING JOURNAL 123

Howard E. Adkins Memorial Scholarship Rick L. Sheridan Rick demonstrated his aptitude and enthusiasm for welding early, by being selected for his high school welding team as a sophomore, an honor usually

reserved for juniors and seniors. His team won the Wyoming Welding Championship three years running. During his high school career, he was also accepted as a member of the National Honor Society.

However, Ricks greatest passion was for welding. Upon completing high school, he attended Eastern Wyoming College for its academic reputation and because it is an AWS Accredited Test Facih'ty. Within a year, he became a certted welder. Concurrently, he started working in the field. His professional efforts solidified his interest in becoming a welding engineer. To complete his education, he enrolled at Montana Tech, where he will complete his studies in May 2002.

Rick has been an AWS Member since 1997.

Airgas - Terry Jarvis Memorial Scholarship Brian K Muenohau Brian began his welding education as a freshman in high school in his native

,,.- ~ - Illinois. He began competing in ~ " q l ~ ~ AWS/VI~ welding competitions as a

junior in high school, where he took eighth place at the state level. In 1995, his senior year of high school, Brian won the gold medal in the Illinois championship, which qualified him to compete nationally. Upon receiving the gold in Nashville, he became eligible to compete in the Weld Trials held during the AWS Expo in Cleveland. He won a runner-up berth behind Brandon Muelbrandt who went on to compete at the international competition in Lyons, France. The following competition cycle, he again won the rmmer-up's position behind the international competitor. For the next competition, Brian was instrumental in preparing Ray Connofiy, the competitor for the World Competition, who won the gold for the U.S. In the midst of preparing for these competitions and earning his keep as a welder, Brian enrolled at ndleville Area College and completed his associate's degree in App~ed Science of Welding Technology. He is currently enrolled at Ferris State University in the Welding Engineering Technology program where he eapects to enrn his degree in May 2001.

!i I

Roman E and Lillian F. Arnoldy Scholarship Darn C. Nielsen Darin is a junior at Utah State University worldng toward a bachelor's degree in Welding Engineering Technology to be awarded in 2002. He has a thorough

background in welding beginning at the age of ten and working at his father's side by age twelve. Professionally, he has more than 20 years experience welding structural steel, using GMAW processes, and performing precision welding requiring exacting detail. He is an AWS Certified Welder in various processes. An avid snowmobiler, he owns and operates a snowmobile parts and repair shop where he spedalizes in customizing tube chassis for competitions. He was also a dedicated scout who attained his Eagle Scout award at age thirteen.

Edward J. Brady Scholarship Jonathan M. Stewart After completing a tour of duty in the U.S. Army in 1995, Jonathan was looking for a new direction in life. At the recommendation of his wife, he took a course in metal sculpting to fulfil a

humanities credit at Salt Lake Community College. It took one assignment manipulating a pool of molten steel to get him hooked on the "magic" in the science of welding. This resulted in his enrollment in a dedicated welding technology program, which he aced with honors. This interest also led to his employment as a welder and fabricator over the past three rears. Jonathan is currently enrolled as a junior at Utah State University. He is working toward a bachelor's degree in welding engineering technology.

John C. Lincoln Scholarship Joshua A. Dudley Joshua was inspired early by his family's machine shop. He watched as his father and undes simply made whatever items they needed instead of going out and buying them. He has applied this orientation to his work and studies with a high- tech spin. For the past three summers he has been working as a welding engineer at the Spring Hill Saturn plant where he has been designing and testing robotic welding cells for implementation into automobile production. He has used a variety of computer, electronics, welding and other skills to solve problems for his employers and in his active extracurricular interests including motocross racing, the Engineers Coundl, drag racing and computer programming. A senior at The Ohio State University, Joshua will complete his bachelor's degree in Welding Engineering in spring 2001.

Donald F. Hastings Scholarship Joshua D. Relding Joshua has already distinguished himself as a student working toward his bachelor of sdence degree in welding engineering at The Ohio State University. Currently maintaining a 3.9 cumulative

grade point average, he has been accepted to the dean's list and has achieved a number of academic honors scholarships. He completed his associate of science degree in Welding Engineering Technology with honors at Ricks College in 1999. There he distinguished himself in math, sciences, welding and engineering. A Certified Welder in four processes, Joshua has worked in several capacities since 1998. These included a freelance welding business, a fabricating company supervisor and a welding engineering internship. He is concurrently working as a welding engineering consultant and a robotics lab instructor at The Ohio State University.

Praxair Intemational Scholarship Wesley W. Donath A high school National Honor student, Wesley is descended from two generations of welding practitioners. However, it took a few years of education

in another field before he awoke to his true calling. Since he enrolled in Ferris State University's Welding Engineering Technology program, he has exerted himself in maldng a difference. He is currently the secretary of the AWS Student Chapter in the school, a capacity in which he has served for the past two years. In his first year at FSIJ, he was the student representative. While working toward his degree, he is concurrently pursuing an associate's degree in iecbanical Engineering Technology and working toward a quality technology certtcate.

4> Foundation,Inc. A Foundation of the American Welding Society

550 NW LeJeune Road, Miami, FI 33126 (800) 443-9353, ext. 293 or (305) 445-6628 FAX: (305) 443-7559 • e-mail: [email protected] www.aws.org/foundationfmdex.html

ILL-MO Products Breaks Ground for New Plant

ILL-MO Products Co., Jacksonville, II1., recently broke ground for a 40,000-sq-ft facility that wil l house all of the company's operations under one roof. The facility wil l house its headquarters, warehouse, service center and cylinder fill operations. The company, a supplier of industrial and medical gases and welding andcut t ing equipment, currently occupies 17,000 sq ft in two buildings.

EWI Receives Award The Edison Welding Institute (EWl), Columbus, Ohio, re-

cently was among five recipients of the first-ever Technology Partnerships Alliance Awards from The Ohio State University. EWl was recognized for its role as an intermediary organization to the university and to industry. EWl and Ohio State have collaborated for more than 15 years in advancing materials joining technology.

Carpenter Opens Large Service Center

Skip Reinert (left) and Phil Bugler (second from right), both marketing managers, U.K., for Carpenter Technology Corp., along with members of the property management firm, celebrate the opening of the company's new steel service center with a sym- bolic key exchange. The 13,000-sq-ft building in Redditch, Worcestershire, U.K., is twice the size of the company's original facility, which was located three miles away. The center wil l serve customers in the U.K., the Republic of Ireland, Africa and the Mideast. Headquartered in Reading, Pa., Carpenter produces more than 450 specialty alloys.

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Bug-O Systems has been showing manufacturers how to automate their welding applications for more than 50 years. We would be happy to discuss any applications you have in mind.

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O Bug-O Systems

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WELDING JOURNAL[ 25

N e w P r o d u c t s For more information, circle number on Reader Information Card.

Highlighting Cutting Equipment and GTAW

used in the structural building, heavy equipment, truck trailer and shipbuilding industries. The laser can process special alloys, such as titanium, Inconel® and Hastelloy. Enhanced pulsing capabilities allow for peak pulses of up to 12 kW.

PRC Corp. 101 N. Frontage Rd., Landing, NJ 07850

Tungsten Grinding Machine Helps GTAW Ignition

The Kaindl WIG 4 electrode sharp- ener longitudinally grinds the point on the rod. For gas tungsten arc welding, it helps produce good ignition, a stable arc, long electrode life and less amperage draw. Operators can set angles of 15, 30, 45, 75 and 90 deg.

TM & HGD Inc. 102 2460 N. Powers Blvd., Ste. L, Colorado Springs, CO 80915

GTAW Power Supply Offers High Amperage

The 400-A Model 415 welding automation control and power supply system can be used to weld all alloys weldable with GTAW using direct current electrode negative. Basic features include water cooling and gas control, which are necessary to operate all of the company's orbital weld heads for in-place field welding tasks ranging from small-diameter tube welds to heavy-duty piping and vessels. According to the company, almost all function ranges and modes can be defined by the user to match the welding head or fixture being used. These include adding up to four optional closed-loop motor servos and eight optional open-loop motor manipulator controls.

Arc Machines, Inc. 100 ,, Pacoirna, CA 91331

Machine Simultaneously Deburrs Top and Bottom Edges

The BRM 2266 production deburring machine simultaneously deburrs top and bottom edges of cut rounds. The machine can process ferrous and nonferrous metals, as well as plastic solids and cylinders from 2 to 6 in. in diameter and 2 to 6 in. in cut length, at rates up to 6000 parts/h. Stock is placed on an in- feed table and moved by a drive belt past the top and bottom nylon mesh, abrasive belts that deburr outside edges. The belts are canted to utilize their full width.

DoALL Co. 103 254 N. Laurel Ave., Des Plaines, IL 60016

Dry Plasma Cutting System Features High Amperage

The HySpeed HT4400 400-A dry plasma arc cutting system is designed to cut Y2-in. mild steel at 160 in./min and

Laser Features High Cutting Power

The FH 6000, a fast-flow CO 2 6000- W laser, provides high power for cutting, welding and cladding. The added power makes possible high-speed cutting of thin materials and increases the capability for processing thick mild steel, stainless and aluminum. The laser can

process carbon steel up to 11,~ in., stainless up to 1Y~ in. and aluminum up to Y~ in. The laser allows for deeper weld penetration and increased welding speeds. Cladding productivity is improved because higher power maximizes powder deposition and buildup per pass. The laser can cut and weld a variety of "primer" treated thick plate commonly

26 I MAY 2000

1-in. mild steel at 65 in./min. Micropro- cessor controlled, the system features a single-source power supply. It is designed for high-volume metal cutting operations to complement laser systems, where increased productivity and thickness capability are required. The torch makes straight or bevel cuts.

Hypertherm, Inc. 104 P.O. Box 5010, Hanover, NH 03755

Semiautomated GTAW Systems Provide Good Productivity

The company's systems, which inte- grate GTAW power supplies with weld programming software and lathes, offer improved control of welding and positioning for assembly. The systems offer storage and retrieval of specific weld programs. The semiautomated systems

may be configured in low amperage ranges down to 2.0 A and high amperages up to 300 A. Applications encom- pass fabrication of medical instruments, repair of aircraft parts and joining of automotive components.

Process Welding Systems, Inc. 601 Swan Dr., Smyrna, TN 37167

105

Control for Cutting Systems Is User Friendly

The Vision PC CNC cutting machine controller incorporates the Windows® 98 operating system and is designed to be user friendly. The controller is available on the company's plasma, oxyfuel, laser and water jet cutting equipment,

and may be retrofitted to older machines. Station and process control are integrated into an operator's panel. Pro- grammable station selection turns on cutting or marking stations via the part program. Selection of correct cutting speed, torch height, kerf, gas pressures and other cutting parameters is automated. The controller combines an industrial-based CPU, a 10.4-in. color LCD, a four-gigabyte hard disk drive and a 3.5-in. diskette drive. Other features include an eight-position joystick, hand wheel and speed potentiometer. A

plasma pre-stop improves consumable life by shutting offthe plasma arc slightly before reaching the end of the cut.

ESAB Cutting Systems 411 S. Ebenezer Rd., Florence, SC 29501

106

Plasma Arc Cutting Machine Offers Portability

The 40-1b AirForce TM 250A plasma arc cutting machine can be used in HVAC, farm, auto body/repair, do-it- yourself and maintenance and repair ap-

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W H Y USE A D E D I C A T E D T U N G S T E N G R I N D E R ? SAFETY Enclosed grinding area captures Tungsten dust for easy disposal.

WELD Q U A U T Y 20 Ra surface finish improves Tungsten life, arc starting, arc stability and produces consistent weld penetration.

PRODUCTIVITY Correctly and consistently Diamond grind your Tungsten Electrode longitudinally, in less than 30 seconds.

VAI.I/E The PIRANHA II Diamond grinds, flats and notches your Tungsten economically.

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Phone (805) 498-3837 • FAX (80.5) 498-93,t7 Email: sa [email protected] • Website: www.diamondground.com



plications. With a built- in, piston-driven air compressor, the operator can plug it into a 115-V household outlet and begin cutt ing. The uni t cuts e lec t r ica l ly conduc t ive metal, i nc lud ing steel, a lu- m inum, stainless steel, brass and copper, in thicknesses of up to 1/, in. It comes with an ICE-12C torch, a 15-ft torch and workp iece c lamp cable, electrodes and extra tips. The unit 's pos t f low coo l i ng

Designed by Sciaky & Manufactured for the Millennium

I "" J' ,~. "~1

For the past 60 years, we have built a reputation as a leading manufacturer of welding equipment at the forefront of technology. Today, our market includes automotive, aerospace, consumer products, etc. We offer total system design, manufacture, installation and service. Let us design and build your next welding system.

Advanced Arc Welding Machines Sciaky designs and manufactures standard AcuWelcP systems and specialty arc welding systems for a variety of applications. Our capabilities include, GTAW, PAW, VPGTAW, VPPAW, GMAW and MPAW.

Electron Beam Welding Machines Our electron beam technology provides clean, precision joining of hard-to-weld materials from foils to heavy sections. Producing very little distortion, EB welding systems are capable of great speed and accuracy and are suitable for the fabrication of high-precision assemblies or performance welding, and surface heat treating. Resistance Welding Machines Sciaky's resistance welding equipment has set the standard of excellence for joining steel, aluminum, nickel-based alloys and other hard-to-weld materials. Try our new Sigma Six ~ SPC resistance weld control with complete data acquisition capabilities.

CD (capacitor discharge) Welding Machines These high-energy welding machines offer extremely short welding time. The high reproducibility makes this a favorite among automotive, home appliance and building industries. Machines range in power from 800W to 60,000W and come in three sizes: Table, C-frame and Press-frame. Contract Welding Services We offer a contract welding bay that is more than 10,000 square feet that house four EEB welding machines, plus a complete testing and evaluation laboratory. We have part welding capabilities up to 22 feet in length.

Upgrades & Retrofits If you have changed a production parameter, are in need of additional output, or would like to add new capabilities to existing equipment, contact us to start the project rolling.

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28 I MAY 2000

ci rcu i t is designed to extend the l i fe of the torch and tips by coo l ing them with air after the trigger is released. The pi lot arc a l lows the mach ine to switch between a cutting arc and a pi lot arc wi th- out pu l l i ng the trigger. The cut t ing arc switches to a p i lo t arc when there is a break in the mater ia l be ing cut, then switches back to a cutt ing arc when the next piece is ready.

Hobar t Brothers 107 600 W. Main St., Troy, OH 45373

H o l e - C u t t i n g D e v i c e A t t a c h e s to S t a n d a r d P l a s m a A r c T o r c h

The Plasma-Pal motor ized hole-cut- t ing device attaches to a standard hand- held plasma arc torch, enabl ing the op-

,

erator to cut accurate holes. Plasma arcs cut clean holes in steel or a luminum up to 1 '/2 in. thick. Hole sizes are adjustable from Y2 to 8 in., and centers are found with a cross-hair sight gauge.

Heck Industries, Inc. 1480 Old U.S. 23 S., Hartland, MI 48353

108

A i r - D r y i n g System I m p r o v e s P l a s m a A r c C u t t i n g

The M-26 and M-60 sub-mic ron ic compressed air filters remove contamination from the plasma arc. The M-900 is designed for areas wi th ex t reme hu-

~! ~Z ! ! ¸:!c Z ¸

midity, where water vapors persist in the air. The system scrubs the air of mois- ture, o i l and par t icu la te down to 0.01

micron, then uses a desiccant dryer module to absorb all uncondensed water vapor, producing a -40°F dewpoint.

Motor Guard Corp. 580 Carnegie St., Manteca, CA 95337

109

Welding Lathe Provides Accurate Rotation

This welding lathe is designed for gas tungsten arc, plasma arc or laser beam welding. The headstock is designed to

specialty studs are custom manufactured up to Y~ in. The studs can be rapidly welded into place by inserting the stud into a welding gun and positioning it against the desired work surface. The hammer mode control cycle then uses the stud to peck through the mill scale. The control repeats this pecking method until it finds ground and welds the stud onto the clean surface.

Image Industries Inc. 382 Balm Ct., Woods Dale, IL 60191

111

Helmet Is Solar Powered

The FOCUS GFM-S solar-powered autodarkening welding helmet is con- structed with light-absorbing glass that does not cause interference problems from sunlight and area lighting. It has two sensors to monitor welding to ensure the filter remains in the dark state while welding. It is 120 x 90 x 12 mm with a 98 x 45-mm viewing window.

Nassau International, Inc. 24 S. Lafayette Ave., Morrisville, PA 19067

112

provide accurate rotation. The tailstock has an air advance/retract feature. The torch tower also retracts for part load- ing and unloading. The lathe may be tilted for horizontal or vertical welding.

Pro-Fusion Technologies 110 1090 Lawrence Dr., #104, Newbury Park, CA 91320

Hammer Stud Welds Penetrate Rusty, Scaly or Painted Surfaces

These hammer stud welds will penetrate rusty, scaly or painted surfaces. The studs provide a durable and efficient alternative to traditional welding methods because they eliminate the need for grinding the surface before welding. Available in steel or stainless steel, the



IliUm i nat ions of an AC TIG weld bead, you control

profitability. The perfect bead takes less time to weld and looks great without grinding or polishing. This aluminations explains how balance control and output frequency affect penetration depth, bead width, etched zones - - and your bottom line.

Shedding light on aluminum welding

questions ANSWERS

Q: How can I weld thinner materials or small parts without burning through? A, Using an inverter, select a pointed tungsten and weld with an output frequency of 80 to 120 Hz. This narrows the arc cone so you can direct the arc right where you want it. You can establish the weld puddle faster and precisely place the filler wire. This helps prevent the burn-through and~or warping that you might experience with a conventional TIG welder and a balled tungsten.

Q: How can I tell if I'm over-welding? A. Excessive bead width can be one indication. For example, a fillet weld has a triangular shape. Assuming good penetration, the longest "leg" should be no longer than the thinnest plate. When joining 1/8 in. to 1/4 in. plate, you only need a 1/8 in. bead. Any wider and you lose travel speed and waste filler wire and gas; the bead may also require post-weld grinding.

Q: Experience tells me that I need to over- weld for good penetration. How can I ensure penetration with a narrow bead? A. I f you~e only used a conventional AC TIG machine, the need to over-weld is understandable. You have very limited control over bead shape. For precisely tailoring bead width and penetration ratios, use a TIG inverter like the Dynasty ~ 300 DX. It permits increasing ou~out frequency and extending balance A 200 Hz output control which, created this narrow, respectively, narrows the yet deep, weld head.

bead and directs more heat into the ~'eldment for deeper penetration.

Mike Sammons TIG Product Manager Miller Bectrlc Mfg. Co.

An AC/DC TIG inverter fine tunes the weld bead profile by controlling arc cone shape and arc force. Think of an inverter like adding a nozzle to a fire hose; it lets you

~.e~ change the shape and force of the "water" (welding current) from a wide fan to a more focused stream. But instead of tuming a nozzle, you adjust balance control and output frequency.

Balance control adjusts the ratio of electrode positive (EP) to electrode negative (EN). During EN, the welding currant travels from the tungsten to the work. Increasing EN duration better defines arc cone and directs more heat into the work. This creates deeper penetration, a smaller bead and pulls the etched zone closer to the weld bead. Compared to conventional Extending the Dynasty's machines, balance control to 90% EN

narrowed the etched zone. inverters let you add about 25% more heat into the work in the same amount of time. This increases penetration per amp of welding power.

EP does not create a well-defined arc cone because the electricity wanders slightly while it searches for the path to the tungsten. Addingmore EP provides shallower penetration, a wider bead, more cleaning and a bigger etched zone.

Frequency and Fillet Welds

Frequency, or Hz, is the number of times the arc switches between EP and EN in one second. The Dynasty permits adjusting output frequency from 20 to 250 Hz. Conventional TIG machines have a frequency fixed to that of the primary power (e.g., 60 Hz). Frequencies below 60 Hz transfer more energy into the work and create a wider bead with decent penetration - - an ideal combination for build-up work or to catch both edges of an outside comer while maintaining travel speed.

Increasing the frequency ("constricting the nozzle") narrows the shape of the arc cone and increases the arc force. This stabilizes the arc, reduces arc wandering and provides excellent directional control over the arc (in fact, it might remind you of the DC arc used on steel). On lap and T-joints, using a higher frequency lets you establish the weld puddle exactly at the root. This can ensure good penetration, control bead width and minimize the etched zone. With a 60 Hz output on fillet welds, the wider arc dances from plate to plate. The puddle starts at the toes of the weld and flows toward the center; on some joints, you're almost compelled to over-weld to ensure penetration at the root.

For a free technical article on how TIG inverter technology helps solve welding challenges, call 1-800-4-A-MILLER (1-800-426-4553) or visit www.MillerWelds.com/ACTIG to view a live arc shaping video.

This high-speed photograph shows how a 200 Hz output eliminates arc wandering.

Weld Shop Keeps U.S. Coast Guard Always Ready

The Integrated Support

Command's welders

utilize portability and

maneuverability when

repairing boa ts

W ith a history going back to the late 18th Century, the U.S.

Coast Guard stands always ready to re- spond to public needs in a wide variety of maritime activities. This includes maintaining safe and secure ports, pro- tecting the marine environment, ren- dering aid to people in distress, managing the waterways to ensure safe traffic a n d - especially in M i a m i - enforcing the law.

The Integrated Support Command (ISC) industrial weld shop for the U.S. Coast Guard in Miami stands ready, too, with its reputation as a premier station for ship alterations and repair, using plasma arc cutting machines and inverter gas tungsten arc (GTA) and gas metal arc (GMA) welding machines, which are portable and have multiple- metal flexibility.

Ship Alterations One of the primary vessels for law

enforcement, mainly drug and illegal alien interdiction duties, is the 110-ft (33-m) Island-class patrol boat (WPB)

- - Fig. 1. These vessels are also involved in port security, search and res- cue and defense readiness operations. With excellent range and seakeeping capabilities, an Island-class patrol boat displaces 154 tons of water, has a max-

Based on a story from Miller Electric Mfg. Co., Appleton, Wis.

Fig. 1 - - A I l O-ft U.S. Coast Guard pat ro l boat.

imum speed of more than 26 knots and an armament of one 25-mm and two .50-caliber machine guns. Built in the late 1980s, the boat is equipped with advanced electronics and navigation equipment.

When vessels need retrofitting, modification and r e p a i r - ship alterations, or "ship alts" in shop language - - they spend three weeks dockside at ISC. Ship alts may include a total engine overhaul, reconfiguring the fuel tank, installing new piping for drains and sewer tanks, replacing fin stabilizers, mess hall work (Fig. 2), reconfiguring deck lights, replacing the hydraulic lines for steering, installing new throttle cable assemblies, hull refitting (from filling in small indentations to replacing whole sections) and resurfacing of the propeller, the propeller shaft and rudder.

The Miami ISC, because of its reputation, usually has ship alts scheduled seven months in advance. In addition to working on the 110-ft cutters, ISC is currently performing a complete overhaul on several 41-ft (12.3-m) utility boats (all vessels under 65 ft [19.5 m] in length are classified as boats; a "cutter" is basically any vessel 65 ft in length or greater).

On Location Ship alts often involve cutting out

sections of worn, outdated or damaged metal parts. Metals commonly encountered include marine grade (5086) aluminum for the hull, radar arch, railings and cleats; British steel (HY 80), also for hulls; steel and aluminum for the mess deck; and copper-nickel alloys for the plumbing. Because of the variety of metals encountered, and the need to work quickly, ISC uses the plasma arc cutting process for most metal removal.

"If the metal can conduct electricity, we believe it's a job for a plasma cutting machine," Nathiel Roper, a welder at ISC's industrial weld shop, said. Plasma arc cutting is a process where an arc is constricted by passing it through a small nozzle from the electrode to the workpiece.

Plasma arc cutting provides numerous advantages over other cutting methods. It's faster than a saw. It cuts any electrically conductive metal, where as oxyfuel cannot cut stainless steel or aluminum. Plasma cuts faster than oxyfuel. A preheat cycle is not required. The kerf width (the width of the cut) is small and more precise. Its smaller heat-affected


Fig. 3 - - A section of a util ity boat's hull with pitting. A worn section (circular shape) with especially deep pitting has been removed with plasma arc cutting and a new section has been GTA welded in its place.

Fig. 2 - - Stainless steel silverware holders for the mess hall on a cutter. A plasma arc cutting machine cut the holes, while the tubes were gas tungsten arc welded in place.

zone prevents warping or damaging paint in the surrounding areas. In addition, it is cleaner, less expensive, safer and more convenient because it uses or- dinary compressed air for "fuel" instead of potentially harmful gases, a real concern when working in a ship's hull.

Conventional plasma arc cutting was introduced in 1957. For decades, the technology was restricted to the shop floor of traditional metalworking industries because transformers within the machines made them heavy, bulky and not very portable. In recent years, however, advanced inverter technology has reduced the size and weight of the machines and freed them from the shop floor.

David Hall, who was ISC's industrial weld shop leader prior to a promotion, said his plasma arc cutting machine is one-eighth the size of the shop's older machines. The small machine can cut approximately 20 in./min on 3/8-in. (9.53-mm) aluminum.

Vic Miller, a welder at ISC, used the plasma arc machine to cut away a large section of a utility boat's hull where the 5/~6-in. (7.94-mm) thick aluminum hull plating had eroded to less than 75% of

its original thickness. Other than a brief pass with a disc sander, no additional finishing was required before fitting the new hull plating in place. The new sections of plating will also be cut with an inverter plasma arc machine, shaped on ISC's press brakes and gas metal arc welded with the Miller XMT 304 inverter-based welding machine and XR- A push-pull wire feeder

running 0.035-in. (0.889-mm) diameter 5356 wire. The whole setup is portable.

Roper added the shop uses the plasma arc machine for cutting expanded metal for servicing the platform on light buoys. Workers flip a switch to keep the pilot arc in a continuous mode, which keeps the arc from going out.

The shop uses the plasma arc to cut steel up to 1 '/~ in. (2.86 cm) thick. "1 slow down my speed and listen for the arc coming out the bottom of the plate," Roper said, "and that ensures that I've got a clean cut."

For gas tungsten arc welding, Roper gets into tight, confined spaces, such as in the battery room, the aft steering space or near the fuel cells. He especially uses the GTAW machine for pipe fitting, tack- ing the pipe for fit and positioning while inside the cutter, then taking it back to the weld shop for finishing.

Repairing Hulls The GTAW machine's AC frequency

can be adjusted, allowing more heat into the work, higher penetration and more cleaning. Miller said frequency

adjustment helps when repairing the hulls and other aluminum structures on older vessels.

"See the pitting on the hull (Fig. 3) where electrolysis has set in? Over the years," Miller said, "salt works its way into the metal, plus the aluminum oxides get in really deep. We need a more penetrating arc to penetrate down into the material. Then, when the aluminum melts, the impurities get raised to the surface of the molten metal. Then I can start adding filler rod."

Before welding, Miller uses a small die grinder to grind out the bad metal in small pits on the hull that sandblasting can't remove. For especially deep pitting, he'll cutout a small portion (a 3- or 5-in. [7.62- or 12.7-cm] diameter circle) with the plasma arc machine and weld new plate in its place - - Fig. 3. Using a 2%-thoriated tungsten electrode, Miller boosts the frequency beyond 60 Hz and starts welding. This is possible on an inverter-based machine, which allows operators to adjust welding output frequency from 20 to 250 Hz.

Increasing frequency produces a tight, focused arc cone, which narrows the weld bead and creates a penetrating arc. It also allows operators to direct the arc at the joint to avoid having the arc dance from plate to plate.

Roper uses increased frequency and an AC balance control when rebuilding a stuffing tube, which is Schedule 120 aluminum pipe that goes through the hull and holds the propeller shaft. Good welds are mandatory because the weld seals the stuffing tube against water en- tering the hull.

Yet, the welding is difficult. First, it involves joining new metal to old metal subjected to oil and salt. Second, since he can't weld from the inside of the pipe,

32 I MAY 2000

Roper relies on arc force and good joint preparation for complete penetration. He also allows about 2 in. (5.08 cm) of clearance between the bottom of the stuffing tube and the hull.

"You have to be a contortionist to weld a stuffing tube. I use a mirror to see where I'm welding," Roper said. For welding the top of the tube, he sets the frequency control to about 110 Hz and extends the balance control to nearly the maximum penetration setting.

"When working on top and on relatively clean metal, I can boost both the frequency and the penetration because the weld pool falls right into the joint," Roper said. "For dirtier metal, I set the balance control for more cleaning. The same thing holds true for the bottom of the weld. There, I must use a lower setting so that gravity doesn't suck the weld pool out of the joint. However, I keep the frequency high. This gives me a tight arc cone for working in that small space, and it gives me good penetration." •

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WELDING JOURNAL I 3g

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Code Week continues with correspondi~ subjects geared to engineers, supervisors, planners, welding inspectors, and welding technicians. Since your work is based on a reputation for reliability and safety, y o u want the latest industry consensus o n prequalification and qualification. If you want to improve your competitive position b y referencing the latest workmanship standarclsi inspection procedures and acceptance criteria - - you won't want to miss this seminad Each day will be in-depth, intense, and more than

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Code/Location Date

D1WIOI: Houston, TX Mar 6, 2000 DIWI04: Atlanta, GA Aprtl 3, 2000 D1Wl02: LOs Angeles, CA May 8, 2000 DIW105: Las Vegas, NV May 22, 2000 DIW103: Chicago, IL Jun 5, 2000 nlWl06: Phildelphia, PA July 10, 2000 D1W107: Detroit, i l August 21, 2000

(Day 2-Tuesday) Design of Welded Connections Member ~345 Non-Member $420

(Day 3-Wednesday) Qualifications Member $345 Non-Member $420

D1W201: Houston, TX Mar 7, 2000 D1W204: Atlanta, GA April 4, 2000 DIW202: Los Angeles, CA May 9, 2000 DIW205: Las Vegas, NV May 23, 2000 DIW203: Chicago, IL Jan 6, 2000 31W206: ehildelphia, PA July 11, 2000 31W207: Detroit, i I August 22, 2000

D1W301: Houston, TX Mar 8, 2000 D1W304: Atlanta, GA April 5, 2000 D1W302: Los Angeles, CA May 10, 2000 D1W305: Las Vegas, MY May 24, 2000 D1W303: Chicago, g Jun 7, 2000 DlW306: Phildelphia, PA July 12, 2000 D1W307: Detroit, i l August 23, 2000

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Inverter-Based GTA Welding Machines Improve

Fabrication Advances in power source technology have made gas tungsten arc welding a more

reliable, efficient and productive process for metal fabricators

BY MIKE SAMMONS

W rhile known as a precision process, many fabricators using the gas tungsten arc welding (GTAW) process fight

several common problems that hinder quality, slow production, frustrate the operator and otherwise prevent the process from achieving its full potential. These include a limited ability to tailor the weld bead profile, poor control of the arc direction and arc wandering, poor arc starting, unstable or inconsistent arcs in the AC mode, high-frequency interference with electronics and tungsten contamination.

Fortunately, new GTA welding technology - - made possible by advances with inverter-based power sources and microprocessor controls - - can eliminate common productivity gremlins. Further, new AC/DC inverter-based GTA power sources provide advanced arc shaping capabilities. As a result, many fabricators adopting this new technology have experienced phenomenal production increases, taken on new types of projects and reduced costs. Most importantly, the operators enjoy welding more.

Advanced Square-Wave Performance Since the mid-1970s, the standard for AC/DC GTAW tech-

nology has been square-wave AC output technology - - Fig. 1. This technology minimized the problems inherent with AC welding: arc rectification and arc stumbling, wandering and outages.

These symptoms were usually exhibited by nonsquare-wave machines during the electrode negative (EN) to electrode positive (EP) transition of the AC sine wave. Sometimes, these older units did not have enough "push" to drive the arc through the zero crossing and then reestablish the arc in the opposite polarity.

If five or six EN-to-EP cycles failed in a row, it created another problem: the welding output began to resemble DC. If this occurs, a GTAW machine reaches for open-circuit voltage in an attempt to get enough voltage to reestablish AC welding output. Unfortunately, the excess voltage can cause current over- shoots. This may produce tungsten spitting, which degrades weld quality.

Square-wave technology shortened the switching time between EN and EP, so it created a more desirable arc. So desirable, in fact, that all high-end AC GTAW machines now feature this technology. Today, the advanced square-wave technology (Fig. 2) employed in an inverter-based GTA machine takes EN to EP switching time a quantum leap forward.

MIKE 5AMMONS is Product Manager and Welding Engineer, Miller Electric Mfg. Co., Appleton, Wis.

Inverters use advanced power switching semiconductors (you might hear them called IGBTs) and microprocessor con- trois that operate thousands of times faster than "conventional" power switching devices and controls. As a result, inverters push the arc through the zero crossing very quickly. This very quick transition improves weld quality and consistency.

To further speed transition, at least one inverter uses a full bridge rectifier, as opposed to a half-bridge rectifier. Machines with a full bridge rectifier can use a smaller stabilizer. A stabilizer is the "electricity sponge" that maintains the arc when it transitions through zero. The smaller the sponge, the faster the transition. Thus, machines with a full bridge rectifier produce the truest square-wave output and have the smoothest, most consistent AC arc.

Extended Balance Control Using AC to GTA weld aluminum evolved from the need to

remove the oxide layer that forms on its surface. The EP portion of the AC cycle, in which electricity flows from the work to the tungsten, "blasts" off surface oxides. The EN portion of the cycle does the actual welding, directing heat from the tungsten electrode into the metal.

When square-wave AC output was invented 1, it was discovered that an unbalanced AC wave form works best for many applications. Lighter-duty machines feature a fixed balance control set for more penetration than cleaning. Industrial square-wave machines feature adjustable balance control. This feature permits tailoring the EN-to-EP ratio to match an application, typically adjusting EN values from 45 to 68% (55 to 32% for EP).

Inverters, because of their power switching capabilities, provide extended balance control. They allow the operator to fine tune the duration of the EN portion of the cycle from 50 to 90% (50% for EP; adjusting the EP portion of the cycle beyond 50% provides no further benefits).

Increasing time in the EP portion of the cycle removes more oxide and creates a shallower, wider bead. On aluminum, increasing the cleaning action improves quality by minimizing the chance of foreign particles becoming included in the weld.

Greater amounts of EN create a deeper, narrower weld bead, better joint penetration and a smaller etched zone-- Fig. 3. This helps when welding on thick material or when appearance (i.e., a minimal etched zone) is important. Setting an inverter's EN duration to the maximum level creates the potential to deliver

1. Miller Electric Mfg. Co. held the original patents for this technology. Those patents expired in the mid-1990s.


Square-Wave Output Inl~ut A

4 0 . 0 _ i i ] i w I ] i ! i i i i ~ ; i i z t i . .

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-30.0 - . 4 0 . 0 , ~ 1 ~ J ~ j ~ ~ ~ ~ ~ ~ z , f "

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22% more heat to the work compared to a conventional GTAW machine. Adding more heat in the same amount of time permits faster travel speeds. This means fabricators using extended balance control technology can often produce more parts per hour.

No hard rules exist for setting balance control. The typical error involves overbalancing the cycle. Too much EP creates a large ball on the end of the tungsten. Consequently, the arc loses stability and then you can't control arc direction or the weld pool; arc starts also degrade. Too little EP results in a "scummy" weld pool. Add more cleaning action if the pool looks like it has black pepper flakes floating on its surface.

Welding Frequency Control Advanced inverter-based welding machines give operators

another option that dramatically enhances shaping of the bead profile: frequency control. Conventional AC GTAW machines have a fixed output of 50 or 60 Hz, but some inverters let the operator adjust the welding output frequency, such as from 20 to 250 Hz.

Decreasing frequency produces a broader arc cone, which

widens the weld bead profile and better removes impurities from the surface of the metal - - Fig. 4. It also transfers the maximum amount of energy to the workpiece, which speeds up applications requiring heavy metal deposition (such as building up a worn part or making a fill pass).

Increasing frequency produces a tight, focused arc cone. This creates deeper penetration and narrows the weld bead (Fig. 5), which helps when welding in corners, on root passes and fillet welds. It lets operators direct the arc precisely at the joint and not have the arc dance from plate to plate.

Best of all, increasing the frequency, combined with increasing EN duration and using a pointed tungsten, can dramatically increase travel speed and reduce production time. When applied to the right application, improvements from 10 up to 40% are frequently reported.

A good starting point for general welding would be 80 to 120 Hz. These frequencies will be comfortable to work with, increase control of the arc direction and boost travel speed. For a fillet weld application with full penetration in the weld without putting too much amperage in the metal, increase the frequency to 225 to 250 Hz. For buildup work, start at 60 Hz and adjust lower from there.

36 I MAY 2000

Advanced Square-Wave Output

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I Fig. 2 - - Examples of the more constricted arc and smoother weld bead achieved with the advanced square-wave output. Advanced square-wave technology has improved weld quality and arc control.

Extended Balance Control m EN (Work)

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Fig. 3 - - An example of extended balance control. Increasing the electrode negative (EN) cycle ~roduces a narrower bead, deeper penetration and a smaller etched area.

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38 1 MAY 2000

Recommendations for Pointing Tungsten Electrodes Historically, preparing to AC weld required selecting a pure tungsten electrode and forming a ball at the end of the electrode.

Bailing, until now a necessary evil (pure tungsten tends to form a ball), promotes arc wandering, less arc focus and poorer arc starts because electricity likes to come off a point. With a ball, the current can dance around the entire surface. That's why Miller now recommends that, for AC welding, operators should sharpen the tungsten as if they were welding in the DC mode. This is true for all advanced GTAW machines, especially for inverters because it optimizes performance.

Guidelines for preparing a tungsten for AC GTA welding include the following: • Select a tungsten with 2% cerium (2% thorium as your second choice). • Grind the electrode to a point (grind in the long direction, and make the point roughly two times as long as the diameter). • Put a 0.010 to 0.030 in. flat (land) on the end to prevent bailing and to prevent tungsten from being transferred across the arc. • For welding thin metals, use a 3/32-in.-diameter tungsten. Compared to a balled tungsten, a pointed electrode provides greater arc control and lets you direct the amperage precisely at the

joint, minimizing distortion. With a pointed electrode, a skilled operator can place a 1/8-in. bead on a fillet weld made from '/8-in. aluminum plates. Without using this method, the ball on the end of the electrode would have forced the operator to make a larger weld bead, then grind the bead down to final size. Thus, when fitting welded parts together, a pointed electrode can save time. •

Banishing the Arc-Starting Gremlins Conventional GTAW power sources may experience arc

starting problems for a variety of reasons, but they are all linked to getting the weld current flowing between the tungsten and the workpiece. An explanation of what the welding current is trying to do will help.

Whether welding in the DCEN mode (the normal mode for work on ferrous metal) or the AC mode, the current must flow from the tungsten to the workpiece. Starts cause problems because the current must overcome the resistance of the tungsten. That is, the current must heat the tungsten so it becomes a better emitter of electrons; at that point, the arc can jump from the tungsten to the workpiece.

One traditional option for "solving" DC arc starting problems, and the standard method for improving AC arc starts, involves superimposing a high-frequency (HF) current over the welding current. Basically, the HF current forms a path for the welding current to follow and establish the arc. Unfortunately, HF interferes with CNC machines, computers and other electronic equipment because its frequency is similar to a radio's and can be "broadcasted." (One user of continuous HF reported that it affected the accounting computer - - and was changing invoice figures!)

The circuitry in one inverter provides a unique solution that eliminates this concern while delivering much more consistent arc starts. This technology works by starting the weld current in the DCEP mode for a brief time no matter which welding process is chosen. With heat flowing from the work into the tungsten, the electrode quickly becomes a better emitter and the arc starts positively time after time.

Through the machine's front panel, operators can tailor the duration of DCEP starting current from 1 to 200 ms and the "force" of the current from 1 to 200 A. Adjusting these parameters is usually not necessary, as the factory default provides very good starts for most applications. Operators should not have any concerns about starting in this mode.

Advanced inverter-based GTAW machines offer operators several starting methods, but two are superior. The first involves minimizing high frequency for applications that benefit from HF arc starts. In these instances, inverters offer an "HF start only" feature that provides a brief burst of HF at the start of the weld. Once the machine senses the arc has been established, it shuts off the HF to minimize any potential interference with electronic equipment.

Inverters starting in the DCEP mode takes this one step fur-

ther - - they only need HF for 10 ms to establish the arc. Oper- ators using this method report very positive arc starts even at low amperages, and they appreciate the absence of HF wandering and buzzing on the weldment. They also report longer times between tungsten sharpenings-- because less HF is available to cause erosion.

Note that conventional machines not only use HF to improve arc starts, but also usually require continuous HF for AC welding. High frequency helps ensure the arc doesn't stumble as it transitions through the zero crossing. Inverter-based machines do not experience as much difficulty with arc starts or arc stumbling because the machine's microprocessor control and IGBTs operate so quickly. In fact, all good inverters eliminate the need for continuous HF when AC welding on aluminum and other nonferrous metals.

The second superior starting method is with technology that allows lift starting, an alternative to scratch starts. Scratch starts may contaminate the weld with tungsten, but welds made with the lift starting method can consistently pass X-ray or ultrasonic tests. This technology enables the operator to touch the tungsten to the workpiece, lift it off and then have full welding current begin flowing. With the scratch start method, the electrode is hot the instant it touches metal. The lift technology can work in the DC and AC welding modes.

Simplified Layout Even though today's inverter-based GTAW machines have

more features available, manufacturers try to make the control panel as simple and logical as possible. Rather than knobs and switches, some of the newer machines use digital displays and switch pads similar to those on a microwave oven.

At first glance, the control panel may appear intimidating. But, at second look, switch pad control panels are very logical. For example, many of the buttons simply follow the actions that occur on every weld sequence, whether the operator controls them through the machine's front panel or the foot pedal. If an operator wishes to control the weld sequence through the "se- quencer panel" (usually a group of switch pads centered on the control panel), values for following functions need to be set:

• Gas preflow time • Initial current * Initial slope • Main/peak welding amperage • Final slope • Final current • Gas postflow time.


Through the digital display, operators can easily see (and return to) the exact values they set. With rheostats, settings can be approximations. The digital displays may also provide "help messages" to the operator about the status of the machine.

The digital display, coupled with the microprocessor control, provides some inverters with a memory function, let- ting operators store weld se- quences for AC/DC gas tungsten arc and shielded metal arc welding processes. If a shop routinely fabricates certain products or consistently welds three or four types of joints or metals, the memory function speeds changing between projects. A lock-out feature prevents tampering with these pre- programmed settings.

Pulsed GTA Welding b extremely beneficial when welding thin-guage steel and stainless steel.

light weight (around 90 Ib) makes it easily portable, eliminating this old dilemma.

Conventional GTAW machines transform power with a large iron core wrapped with copper and/or aluminum wire. This

makes them heavy. To handle the current used to weld thicker sections of metal, a conventional GTAW machine's transformer must weigh 200 to 400 Ib or more.

Inverters operate on the principle that increasing the current frequency permits re-

ducing the core size and number of wire turns. Before the current reaches the transformer, an inverter boosts the line frequency to 20 to 100 thousand cycles per second. Thus, the transformer on an inverter weighs about 5 lb.

Pulsing All advanced GTAW inverters incorporate pulsed welding

capabilities. Pulsed GTA welding is extremely beneficial when welding thin-gauge steel and stainless steel. It allows the operator to tailor the amount of heat to the application, decreasing distortion and heat input. Pulsing can also help teach beginning welders because it provides a rhythm for adding the filler rod (i.e., adding the filler rod during the peak amperage pulse).

Pulsing controls let the operator tailor the arc by setting background amperage range, pulse frequency (pulses per second) and peak time adjustment (duration of peak amperage). A series of switch pads lets the operator set parameter values.

Location, Location, Location Is work light enough to bring it to the welding machine, or

do you need to move the machine to the job site? An inverter's

Reliability Although inverters have been available since the late 1980s,

many people hesitated to purchase them because of reliability issues. Fortunately, improvements made in the last few years give some inverters a reliability level that approaches that of conventional welding machines.

In fact, one mechanical contractor who wanted program- mable pulsing controls switched from conventional GTA machines to inverters because of the inverter's Wind Tunnel Tech- nology TM. This technology shields the electronic components from potentially damaging airborne particles. The contractor anticipates the dust from grinding stainless steel, which caused constant circuit board failures on conventional machines, will no longer be an issue. •

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Steel Center Consolidates Cutting

Operations to Cut Costs Centralized plate processing facility features plasma equipment capable

of cutting 6-in.-thick stainless steel

E MJ, the largest privately held metal distributor in North America, offers

an impressive array of products and services. Operating from 24 facilities in the United States and two in Canada, products include more than 40,000 sizes, shapes and grades of bar, sheet, plate, structurals, expanded metals, tubing and pipe in carbon, alloy steel, stainless and specialty aluminum and steel.

The company eliminated costly du- plication of equipment and services at each of its locations by regionalizing all of its plate and sheet processing. In 1993, the company's plate processing center in Lynwood, Calif., assumed all the plate and sheet processing of materials sold through the company's western branch locations. Concerned that the increased demand this consolida- tion placed upon the company's existing plasma shape-cutting machine was greater than the equipment could handle, a search was begun for a replacement system in 1997.

Tough Job Cutting Stainless Steel Typical orders require cutting large

blanks from stainless steel plate up to 6 in.(15.24 cm) thick. Customers machine these blanks into parts such as gears or drive train components. In addition to cutting thick plate, the replacement equipment needed the capability of cutting stainless steel plate on an 18-ft- wide and 65-ft-long (5.4 x 19.5-m) table. STEALTH, a large gantry shape- cutting system from ESA8 Cutting Sys- tems of Florence, S.C., was chosen. This system can accommodate up to 12 oxyfuel cutting stations or a maximum of 4 plasma cutting torches. This particular setup was equipped with two 1000-A plasma torches - - Fig. 1. EMJ develops

is cut with 1000-A plasma torches.

part programs off-line and downloads them to the vision controller.

Initially, the equipment manufacturer indicated cutting 6-in. stainless steel was beyond the capacity of this machine. The first attempts to cut 6-in. material proved unsuccessful, as heat generated during plasma arc cutting melted the torch. To overcome this problem, the manufacturer worked two months in its laboratory designing a special brass nozzle to reflect the generated heat away from the torch. The effort proved successful.

In addition to cutting large circular and rectangular blanks from 6-in. stainless steel plate, the company cuts more intricate work linked to manufacturers

Fig. 1 - - Stainless steel up to 6 in. thick

of computer chips in California's Silicon Valley. These chips are produced inside stainless steel vacuum chambers, and the components for the vacuum chambers are cut from 0.190-in. (4.83-mm) stainless steel sheet up through lYe-in. (28.58-mm) stainless steel plate. These parts are approximately 20-22 in. (50.8-55.88 cm) square and have ta- pered edges for welding. All required cuts, including the tapers, are accomplished on the cutting system.

Increasing Cutting Capacity Two more cutting machines were

purchased in 1998, and they cut carbon steel plate up to 12 in. (30.48 cm) thick.

Based on a story from ESAB Welding and Cutting Products, Florence, S.C.


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Repairing an Offshore Jacket Structure Proves Cost Effective

With experienced welders and ideal weather, an offshore repair runs smoothly

BY J. R. STILL AND V. BLACKWOOD

D uring the last 30 years, several jacket structures in the North Sea have sustained damage due to impact by supply or

standby vessels. In most instances, damage has not been significant; however, in the case described here, damage was substantial.

The structural integrity of an offshore structure can be severely impaired by impact damage, so it is essential to verify that the structure's integrity and safety can be maintained until repairs can be performed; in the North Sea, this usually means during the summer, when weather cooperates. Structural damage should be evaluated in accordance with the original design to determine whether repairs need to be completed immediately or if they can wait and be scheduled with other planned underdeck works.

Inc ident

During inclement weather in the southern North Sea, an offshore supply boat collided with a 25-year-old gas production platform. The impact occurred just over 2 m (5.56 ft) from the lowest annual tide and was sufficient to buckle, then shear, one end of a horizontal bracing from the jacket leg and to cause further damage at a node joint.

Examination Inspection personnel performed an initial examination of

the damage to the eight-leg jacket structure using rope access techniques (abseiling), which offered substantial cost savings over erecting scaffolding. The areas affected are shown in Fig. 1, and the damage sustained is in Fig. 2. Damage occurred at the +7.5-ft (+2.25-m) level to one end of the 355.6-ram-diameter x 14-mm-thick (14.2 x 0.56-in.) A2-A3 bracing from the 1016-mm-diameter x 25-mm-thick (40.64 x 1 in.) jacket leg A3 - - Fig. 3. Damage also occurred to the node stubs on leg A2 at the +7.5-ft level, where weld metal cracks were detected between the overlapping horizontal saddle node and bracing tubular on the K node. Shearing of the bracing removed an oval- shaped area 390 x 605 mm (15.6 x 24.2 in.) from the A3 leg - - Fig. 4. It was considered prudent to remove potential fracture initiation sites by dressing the opening smooth. A band 60 mm (2.4 in.) wide around the periphery was examined using magnetic particle inspection, and no surface defects were found. An ultrasonic lamination check performed on an area approximately

J. R. STILL and V. BLACKWOOD are welding engineers in Aberdeen- shire, Scotland.

300 mm (12 in.) around the opening did, however, detect a significant number of inclusions - - Fig. 5A.

A structural analysis confirmed the jacket's integrity was not impaired and loss of the horizontal bracing would not significantly affect the structure. The analysis also confirmed repair of the node weld cracks and of the sheared area on the leg should be performed as soon as practical.

Concurrent with the initial examination, a section that included material from leg A3 was removed from the damaged bracing and was sent for metallurgical investigation.

Metallurgical Investigation A chemical analysis (Table 1 ) of samples removed from the

A3 leg and horizontal bracing confirmed the material was a carbon manganese steel (BS 4360 43A) (Ref. 1). However, sulfur levels for leg A3, 0.026%, and the horizontal bracing, 0.022%, were considered high. Because materials with high sulfur levels have poor through-thickness properties (Ref. 2), it was considered probable the leg A2 material would have similar characteristics. Metallography performed on the leg A3 material

A4 A3 A2 , ~ ~ ~ +50 ff

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Sea Bed

Fig. I - - D a m a g e to j a c k e t s t ructure.


Fig. 2 - - Damage sustained during impact by a supply vessel. Fig. 3 - - Close-up of damage to node section and bracing.

confirmed it had a high volume fraction of Type 2 manganese sulfides. Mechanical properties for the materials of both leg A3 and the horizontal bracing are listed in Table 2. Ultimate tensile and yield strengths satisfied the original design specification, and Charpy impact properties from both materials achieved the nominal requirement of 27 J at 0°C (32°F).

Repair Technique Repairing a jacket structure close to the waterline needs the

weather to cooperate. So, owing to the nature of the damage, it was considered prudent to execute the repair work at the first opportunity. The repairs (Fig. 6) involved the following:

• A 25-mm-thick patch plate (BS 4360 50D) (Ref. 1 ) located over the damaged area and welded to leg A3 with 12-mm (0.48- in.) fillet welds. To minimize the possibility of lamellar tearing, the positions of the inclusions found during ultrasonic scanning around the opening were considered when deciding on the final dimensions of the patch plate - - Fig. 5B.

• Removal and repair of the cracked areas within the saddle node on leg A2.

Weld Procedure

With the damage so close to sea level, there were obvious problems associated with preheating the weld area and the possibility of hydrogen cracking. It was decided to shielded metal arc weld (SMAW) the patch plate using austenitic welding electrodes, which diffuse hydrogen slower and have solubility 30

times higher than ferritic steels (Ref. 3). To ensure hydrogen levels were maintained at the lowest possible level, all electrodes were baked at 300-350°C (572-662°F), then transferred to a heated quiver at 150°C (302°F) in which they were transported to the weld site.

The welding consumable selected was the Avesta P5, AWS A5.4 E309MoL-15 (Ref. 4), a fully positional electrode with good handling characteristics. To qualify the welding consumable, a butt-joint weld, using the same material as the patch plate, was welded in the 3G position. Fillet weld procedure test plates (Fig. 7) in the 3F (vertical) and 4F (overhead) were also performed to ensure the technique was feasible and practical; the details are listed in Table 3. Because using large-diameter austenitic electrodes in position is difficult, the electrode diameter was restricted to 3.25 mm (1/8 in.).

Mechanical properties achieved from the test plates are outlined on Table 4. Charpy impact tests selected from the weld interface and weld interface +2 mm (+0.08 in.) recorded tough- ness values in excess of 94 J at-20°C (-4°F). Heat-affected zone (HAZ) hardness levels measured 173-230 HV 10. These values were considered acceptable, and, with the use of austenitic electrodes with low hydrogen levels, the possibility of hydrogen cracking was considered remote.

Executing the Repair

All repairs were carried out by fully qualified personnel experienced in rope-access techniques. The repair on leg A3 (Fig. 5A) not only involved sealing the opening in the leg with the patch plate, but also the removal of the horizontal bracing between legs A2 and A3. The predetermined welding sequence, outlined in Fig. 8, ensured the deposited weld metal was evenly

Table 1 - - Chemical Analysis of Damaged and Repair Materials

C Si S P

Leg A3 0.20 0.28 0.026 0.02 Horizontal 0.25 0.16 0.022 0.008 Bracing BS 4360 0.25 0.50 0.05 0.05 43A max. max. max. max. Patch Plate 0.17 0.40 0.002 0.012 BS 4360 0.18 0.10/ 0.040 0.04 50D max. 0.50 max. max.

(a) Not determined.

Mn Ni Cr Mo Cu

1.39 0.08 0.06 0.01 0.20 0.95 0.09 0.05 0.02 0.25

1.60 max. 1.48 0.25 0.03 0.02 0.02 1.50 m a x .

Nb AI sol

(a) (a) (a) (a)

0.03 0.035 0.003/ 0.10

44 I MAY 2000

Table 2 - - Mechanical Properties of Damaged Material

Location UTS 0.2% Proof (N/mmJ Stress (N/mmJ

A3 leg 491 296

Horizontal Bracing 572 382

BS 4360 43A 430/580 265 Minimum

Charpy Impacts at 0~C (Joules)

57-44-52 Average 51 92-86-88

Average 89 Not Req u i red

distributed around the patched area, l imiting the development of residual stresses.

The locations of the repairs made it difficult to maintain the required preheat temperature of 150°C. Because conventional preheating using electric induction heating was impossible, preheating was successfully performed using oxypropane heating equipment. The maximum leg length of a fil let weld deposited was 12 mm. Figure 9 illustrates the completed patch to the jacket structure.

To remove the cracks on the node section of leg A2, personnel first dressed each to a depth of 2 mm (0.08 in.); if the crack was still visible, 2 mm more were removed by dressing. This process was repeated until the crack was removed.

Table 3 - - Fillet Weld Procedures

Vertical 3F

Run No.

1 2to3 4 to6

AWS Classification Trade Name

A Number

Diameter Amps Volts Polarity Travel Speed Heat Input mm/s kJ/mm

3.25 105 27 DCFP 1.666 1.7 3.25 105 26 DCEP 1.595 1.71 3.25 105 27 DCEP 1.382 2.0

A5.4 Preheat 150 E309MoL-15 Temperature 8 C

Avesta P5 Interpass 250 Temperature 8 C

A8 F Number F5

Overhead 3F

Run No.

1 2 to3 4 to6

AWS Classification Trade Name

A Number

Diameter Amps Volts Polarity

3.25 105 24 3.25 105 24 3.25 100 24

A5.4 E309MoL-15

Avesta P5

A8

DCEP DCEP DCEP

Preheat Temperature 8C

Interpass Temperature 8 C

F Number

Travel Speed mm/s

1.018 1.093 1.022

150

250

F5

Heat Input k J/ram

2.47 2.3 2.34


Fig. 4 - - Removal of a segment of plate from leg A2.

All dressed areas were examined by dye penetrant inspection to determine defect removal was complete. In most cases, cracks were considered superficial, requiring only light dressing, so only five cracks were removed. Two exceeded 4 mm (0.16 in.), and one even reached a maximum depth of 12 mm. All areas where depth exceeded 4 mm were subsequently repaired using the weld procedure qualified for the patch repair. After completing the welds, all were ground to a smooth profile.

Removal of the A2-to-A3 bracing was completed by oxygen cutting to within 6 mm (0.24 in.) of the surface of leg A2, and then grinding the remainder flush.

Nondestructive Examination

On completion of the work, the bracing removal area and the weld areas were inspected using dye penetrant inspection. Weather conditions had been ideal during the repair work, and, because ideal conditions continued, a second inspection was made after 48 hours to alleviate any fears of delayed hy-

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Fig. 5 - - Location of inclusions detected with ultrasonic examination and dimensions of patch plate. A - - Location of inclusions; B - - location of inclusions and patch plate.

Table 4 - - Weld Procedure Mechanical Test Results and Fillet Weld Procedure Test Hardness Values

Charpy V-Notch (-20~C) Position Joint Tensile N/mmz Test Location Test Results Joules Average Joules

3G (vertical uphill) 515 Weld Interface 98-146-94 113 Weld Interface +2 mm 205-195-180 194

Hardness Test HV 10 (Location 2 mm from top surface)

Base Material HAZ Weld Metal HAZ Base Material

153 199-218 199-203 201-213 160

Location of Hardness Values Base Material - - 2 mm from Surface Weld Metal - - Weld Centerline HAZ - - Profile of HAZ

Fillet Weld Hardness Test HV 10

i!i !!lilting,,:, ..... i! iiiiiiiiiili ....

Position Base Material HAZ Weld Metal HAZ Base Material

3F 166 197-230 202-217 195-224 212 4F 145 173-222 210-299 190-213 164

46 I MAY 2000

A Leg A3 Node Configuration

B Damaged Area

C Location of Patch Plata

A Section A - A'

~ Patch Plate

IDA'

Fig. 9 - - Completed repair to jacket leg.

Fig. 6 - - Repair to damaged leg.

Fig. 7 - - Mac ropho tog raphs o f f i l le t we ld p rocedure (X4): A - - Vertical; B - - overhead.

L'lEICl

lc ' l E' IA'I

Weld sequence

Tack welds A' to D, B to C and root run A to D', B' to C'

Remaining root runs Section A and A' C and C' E and E'

B and D' B' and D F' and F

Completion of weld in accordance with the above sequence

Fig. 8 - - Weld repair sequence.

drogen-induced cracking. After all testing, no defects were encountered.

In addition, ultrasonic inspection using compression and angle probes was used to ensure that no defects, such as lamellar tearing, had occurred.

S u c c e s s

In the end, the repair went smoothly. The repair area was above the waterline, and the weather cooperated perfectly. The repairs were done using rope access techniques, and using austenitic electrodes reduced the possibility of HAZ hydrogen cracking.

Nondestruct ive examinat ion confirmed no cracking had been experienced and no other defects existed. Indeed, this methodology is considered extremely practical, cost effective and ideal for use on offshore structures - - w i th damage close to the waterl ine, and wi th the need to execute immediate repairs. •

References

1. BS 4360, Specification for Weldable Structure Steel. 1990. British Standard Institution, London, U.K.

2. Still, J. R. 1995. Lamellar tearing: a ghost from the past. Welding and Metal Fabrication 63(10): 445448.

3. Jargelius, R. F. A., and Cun-Gan, F. The influence of hydrogen on the mechanical properties and microstructure of stainless steel. Chiba 91, ISJL.

4. AWS A5.4-92, Stainless Steel Electrodes for Shielded Metal Arc Welding. 1992. American Welding Society, Miami, Fla.

W E L D I N G JOURNAL I 47

Call (800) 334-9353 or use the secured server at aws.org to order these ANSI-approved standards Recommended Practices for Gas Tungsten Arc Welding 46 pages on the equipment, filler materials, safety, applications, welding procedures, and qualifications of this highly versatile process. Use order code C5.5-80R. $33 for AWS members, $44 for others.

Recommended Practices for Gas Tungsten Arc Welding of Titanium Piping and Tubing Latest edition of a popular standard than began as a committee report in 1959. 20 pages, 7 tables, 4 figures. Use order code DI0.6/D10.6M:2000. $33 for AWS members, $44 for others.

Site licensed Welding Procedure Specifications on Gas Tungsten Arc Welding of:

Carbon Steel (M-l/P-I, Group 1 or 2) Primarily Pipe Applications, 1/8 through 1-1;2 inch Thick, ER70S-2, As- Welded or PWHT Condition. Use order code B2.1-1-207-96; for 1/8 through 1-1/2 inch Thick, INms-1 and ER70S-2, As- Welded or PWHT Condition - Gas Tungsten Arc Welding with Consumable inserts, use order code B2.1-1-210-96.

For 1/8 through 1-1/2 inch Thick, ER70S-2 and E7018, As- Welded or PWHT Condition- Combination GTAW and SiAW- use order code B2.1-1-209-96.

Aastenitic Stainless Steel Primarily Pipe Applications, 1/8 through 1-1/2 Inch Thick E3Xg-XX, As-Welded Condition. Use order code B2.1-8-212-97; for 1/8 through 1-1/2 inch Thick ER3XX, E3~-XX, As-Welded Condition, use order code B2.1-8-214-97.

Chromium Molybdenum Steels Primarily Pipe Applications (M-4/P-4, Group 1 or 2), 1/8 Through 1/2 in. Thick, As-Welded Condition, OR 1/8 Through 3/4 in. Thick, PWHT Condition. Use order code B2.1-4-217:1999. For 1/8 through 1/2 in. Thick, As-Welded Condition, OR 1/8 through 1-1/2 in. Thick, PWHT Condition ER80S-B2, ESO18- B2- Gas Tungsten Arc Welding followed by Shielded Metal Arc Welding- use order code B2.1-4-219:1999.

Chromium Molybdenum Steels Primarily Pipe Applications (M-5A/P-5A, Group 1 or 2), 1/2 in. Thick, As-Welded Condition, OR 1/8 through 3/4 in. Thick, PWHT Condition. Use order code B2.1-5A-222:1999.

AleS site licenses are for unlimited intra company use. Save time and money conveying procedures to the shop floor- avoid costly mistakes from improp~,, incomplete or inept WPSs. $99 each for AIPS members, $132 each for others. Don't see your application? Call (800) 334-9353 for a complete list of qualified WPSs.

This growing series of standards is noted for its concise explanations of successful fundamentals. Recommended Practices for Laser Beam Welding, Cutting and Drilling All new 108-page standard spells out an industry consensus, balancing process performance, safety, and cost. Sections include process control and monitoring, inspection and testing, equipment maintenance, and safety. Use order code C7.2:1999. $39 for AWS members, $52 for others.

Recommended Practices for Plasma Arc Cutting Reliable favorite. 13 pages. Use order code C5.283R. $18 for AWS members, $24 for others.

Recommended Practices for Air Carbon Arc Gouging and Cutting Hard-to-find information in a succinct 19-page package. Use order number C5.3-91. $18 for AWS members, $24 for others.

Recommended Practices for Shielding Gases for Welding and Plasma Arc Cutting Covers argon, carbon dioxide, helium, hydrogen, and oxygen. 46 pages, 24 tables, 22 figures. Use order code C5.10-94. $33 for AWS members, $44 for others.

Operator's Manual for Oxyfuel Gas Cutting Popular how-to guide. 28 pages. Use order code C4.2-90. $18 for AWS members, $24 for others.

Recommended Safe Practices for Preparation for Welding and Cutting of Containers and Piping Covers various cleaning methods', water, steam, hot chemical, and mechanical. Explains inerting. 12 pages. Use order code F4.1:1999. $24 for AWS members, $32 for others.

Safety in Welding, Cutting and Allied Processes This is the latest edition of "the finest publication of welding safety in the world." Provides major coverage on cutting safely. Use order code Z49.1:1999. $48 for AWS members, $64 for others.

American Welding Society 550 NW LeJeune Rd., Miami, FL 33126 http://www.aws.org

W E L D I N G W O R K B O O K Datasheet 241a

Practical information for welders and others involved in welding and its allied processes.

Oxygen Cutting The chemical reaction between oxygen and an oxidiz-

ing metal heated to a high temperature initiates the sever- ing action of the oxygen cutting (OC) process. The temperature of the metal is maintained with a flame from the com- bustion of an oxygen-fuel gas mixture. A separate stream of oxygen does the cutting.

The cutting torch (see figure) has internal chambers for mixing the fuel gas and oxygen, as well as a separate chamber for delivering high- purity oxygen to the cutting area. The torch nozzle or tip has numerous ports machined into it for regulating and con- centrating the flame and the stream of cutting oxygen.

When iron is brought to a temperature above 1600°F (870°C) and combined with oxygen of 99.5% or greater purity, rapid oxidation occurs. This chemical reaction releases a tremendous amount of heat, which sus- tains the process by preheating the metal at the cutting focal point to its ignition temperature. Some of the iron adjacent to the cutting point also is melted and blown away by the oxygen stream. Oxygen with purity levels below 99.5% significantly decreases cutting efficiency.

Since oxidation of iron is at the heart of the process, metals with high levels of nickel or chromium and nonferrous metals cannot be cut effectively with this process.

There are a variety of fuel gases that can be used in oxygen cutting. Acetylene, with its widespread availability and high flame temperature, is the common choice. De- pending on the shape and color of the flame, the correct ratio of oxygen to acetylene for efficient cutting can be as- certained. Acetylene must not be used at pressures higher than 15 Ib/in. 2 gauge pressure or 30 lb/in. 2 absolute pressure. When used at higher pressures, it can become ex-

plosive under heat or shock conditions. Hoses with specially designed fittings are used in oxy-

gen cutting. The hose for oxygen, which in the United States is green in color, has a right-hand-threaded fitting with a smooth surface. The fuel gas hose, which is normally red, has left-hand threads and the nut is notched.

CUTrING TiP

TIP NUT

MIXED PREHEAT

PRESSURE • OXYGEN MIXER ~ 0 0 MIXED GAS

,41C1 //I LEvERO GEN

FUEL GAS OXYGEN VALVE ~ VALVE

FUELGAS ~ ~ r ~ ~ . . . . INLET ~ INLET

PREHEAT FUEL GAS,

PREHEAT

CUTTING OXYGEN

PREHEAT VALVES,~

DESIGN

OXYGEN

Schematics of two types of oxygen cutting torches.

Excerpted from the Welding Handbook, Vol. 2, 8th Edition.


Datasheet 241 b

Air Carbon Arc Cutting Air carbon arc cutting (CAC-A) brings metal to a molten

state with the heat from an electric arc established between a carbon-graphite electrode and the workpiece - - Fig. 1. The molten metal is removed from the heated area by a strong stream of compressed air. The process can be used for cutting and gouging• The process is not dependent on oxidation of metal for its effectiveness, and it can be used on carbon steels, cast iron, stainless steels and copper alloys. The cutting rate depends on current levels.

Operation of the process (Fig. 2) requires a power source, a compressed air supply, special cutting electrodes and an electrode holder similar to that used for shielded metal arc welding, but designed to deliver a stream of air to the molten metal. With a special controller, the process can be automated.

Welding power sources with at least an open circuit voltage of 60 V can normally be used, but the machine's

manufacturer should be consulted since some power sources are not designed for this cutting process• Cutting torches go from light-duty use at 450 A to heavy-duty production cutting and gouging at 2000 A with water-cooled cables• Compressed air delivered in the range of 80-100 Ib/in. z is usually sufficient, although some light work can be performed with air delivered as low as 40 Ib/in. 2. Never use oxygen as a substitute for air.

The three carbon electrodes used are DC plain, DC copper coated and AC copper coated. Most applications use the round electrodes, but some electrodes are half round or flat for producing rectangular grooves. The electrode most commonly used is the DC copper coated. The DC plain electrode is consumed more rapidly than the cooper- coated electrodes. The AC copper-coated electrode contains ingredients that stabilize the arc and allow cutting to be performed with alternating current.

ST'CKOU+7' ELECTRODE • _ ~ \ ~ I ~ - - - - - T O R C H HEADS (+)

COPPER PEEL BACK / ~ DCEP ON DC ~ 3 / 4 in. TO 2 in. / ~

xC \ A,R . . . .

~ ~ ~ ° ' 3 5 ~0 70 d'" ALWAYS UNDER THE ELECTRODE -

Ftg 1 -- Gouging with the : ~ ~ ~ ~ ~ ~ alrcarbonarcprocess

WORKPIECE (-)

I ~ • • l COMPRESSED AIR

' ' ' " ' 1 l

LEAD

~ \ \ %- CARBON ELECTRODE \ \ CONCENTRIC CABLE - - - -~\ \ \ ~ ~TORCH'-~ \ /-- WORKPIECE

~ ,~v ''-'WORKPIECE ~ ~. ~ /

Fig. 2 -- Equipment setup for air carbon arc cutting.

50 l MAY 2000

Coming Events

31st International Symposium on Robotics (ISR 2000). May 14-17, Montreal, Canada. Contact: Canadian Federation for Robotics, c/o Golden Planners, Inc., 126 York St., Ste. 301, Ottawa, ON K1N 5T5, Canada, (613) 241-9333, FAX: (613) 565-2173.

SAMPE 2000 - - International Symposium/Exhibition. May 21-25, Long Beach Convention Center, Long Beach, Calif. Sponsored by the Society for the Advancement of Material and Process Engineering (SAMPE). Contact: SAMPE, (626) 331-0616 ext. 610., FAX: (626) 332-8929.

EASTEC 2000 Advanced Productivity Exposition (APEX). May 23-25, Eastern States Exposition Grounds, West Springfield, Mass. Contact: Society of Manufacturing Engineers, One SME Dr., Dearborn, MI 48121, (800) 733-4763 ext. 1600 or (313) 271-1500 ext. 1600, FAX: (313) 271-2861.

Lasers for Manufacturing Conference. May 24-26, Arlington Heights, III. Cosponsored by the Laser Institute of America and the Society of Manufacturing Engineers. Contact: LIA, 13501 Ingenuity Dr., Ste. 128, Orlando, FL 32826, (407) 380-1553, FAX: (407) 380-5588.

Note: A diamond( • ) denotes an AWS-sponsored event.

• AWS Rendezvous Conference. August 14-16, The Stanley Hotel and Conference Center, Estes Park, Co[o. Sponsored by the American Welding Society. Contact: AWS Conference Dept., 550 NW LeJeune Rd., Miami, FL 33126, (800) 443-9353 ext. 223, FAX: (305) 443-1552.

• Materials Joining in the New Millennium. August 21-23, The Inn at Aspen Resort and Conference Hotel, Aspen, Colo. Sponsored by the American Welding Society. Contact: AWS Conference Dept., 550 NW LeJeune Rd., Miami, FL 33126, (800) 443-9353 ext. 223, FAX: (305) 443-1552.

4th Conference on Aerospace Materials, Processes and Environmental Technology. September 18-20, Von Braun Center, Huntsville, Ala. Contact: Dawn Cross, Marshall Space Flight Center, (256) 544-1835.

Materials Solutions 2000. October 9-12, Cervantes Convention Center, St. Louis, Mo. Contact: ASM International, (440) 338- 5151.

• Second International Conference on Education in Welding. October 15-17, Denmark. Cosponsored by the Institute for the Joining of Materials (JOM Institute) and the American Welding Society. Contact: JOM Institute, Klintehej, Vaenge 21, 3460 Birkerod, Denmark, +45 45 82 80 95, FAX: +45 45 94 08 55.

SPECIALTY CORED WIRE

FLUX CORED NICKEL BASE ALLOYS FOR FABRICATION AND OVERLAY

MATERIAL DESIGNATION AWS CLASSIFICATION N82 FC ERNiCr-3

N100A FC ENiCrFe-2 N182 FC ENiCrFe-3

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THESE CORED WIRES OFFER IMPROVED WET-OUT, GOOD SLAG REMOVAL AND BETTER BEAD SHAPE WHEN COMPARED WITH SOLID WIRES IN THESE SPECIFICATIONS.

Standard sizes: .045" and 1/16" (1.2mm and 1.6mm) All materials in standard form and packaging available from stock.

COR-MET, INC. • 12500 EAST GRAND RIVER • BRIGHTON, MI 48116 Ph: 800-848-2719 Fax: 810-227-9266

www.cor-met.com

Circle No. 9 on Reader Info-Cnrd WELDING JOURNAL I 51

Educational Opportunities

2000 AWS CWI/CWE Seminars and Exams Exam application must be submitted six weeks before exam date. Exams and seminars listed through October 28. For complete schedule, exam information and application, contact the AWS Certification Dept., (800) 443-9353 ext. 273. For seminar information, contact the AWS Education Dept., (800) 443-9353 ext. 229. To preregister for a seminar, call AWS Customer Service, (800) 334-9353. Dates are subject to change.

Cities Inspection CWI /CWE Cities Inspection CWI/CWE Seminars Exams Seminars Exams

Anchorage, Alaska Oct. 16-20 (API 1104 Oct. 21 Miami, Fla. June 26-30 ]uly 1 clinic also offered) Miami, Fla. EXAM ONLY luly 20

Baltimore, Md. EXAM ONLY Oct. 7 Miami, Fla. EXAM ONLY Aug. 17 Boston, Mass. Sept. 18-22 Sept. 23 Miami, Fla. EXAM ONLY Sept. 21 Charlotte, N.C. EXAM ONLY Sept. 9 Miami, Fla. EXAM ONLY Oct. 19 Chicago, III. EXAM ONLY Nov. 18 Miami, Fla. Dec. 4-8 Dec. 9 Cincinnati, Ohio EXAM ONLY Sept. 9 Milwaukee, Wis. Aug. 21-25 Aug. 26 Columbus, Ohio May 15-19 May 20 New Orleans, La. Sept. 18-22 Sept. 23 Denver, Colo. Sept. 25-29 Sept. 30 (API 1104 clinic Detroit, Mich. June 12-16 June 17 also offered) Fresno, Calif. EXAM ONLY Sept. 2 Norfolk, Va. Oct. 23-27 Oct. 28 Hartford, Conn. July 24-28 July 29 Philadelphia, Pa. EXAM ONLY Sept. 16 Houston, Tex. Aug. 7-11 Aug. 12 Portland, Ore. Oct. 16-20 Oct. 21

(API 1104 clinic/ Salt Lake City, Utah EXAM ONLY Sept. 16 SCWl also offered) San Antonio, Tex. Oct. 9-13 Oct. 14

Idaho Falls, Idaho June 12-16 June 17 (API 1104 clinic also offered) Indianapolis, Ind. Aug. 14-18 Aug. 19

Kansas City, Mo. Aug. 21-25 Aug. 26 Knoxville, Tenn. EXAM ONLY Aug. 5 Las Vegas, Nev.

San Diego, Calif. July 10-14 July 15 San Fernando, Calif. EXAM ONLY June 24

Los Angeles, Calif. EXAM ONLY

Aug. 14-18 Aug. 19 San Francisco, Calif. Oct. 2-6 Oct. 7 (API 1104 clinic Seattle, Wash. Oct. 2-6 Oct. 7 also offered) Tulsa, Okla. Sept. 25-29

Oct. 14 (SCWl also offered) Sept. 30 July 22 York, Pa. July 24-28 July 29 Louisville, Ky. July 17-21


52 [MAY 2000

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• AWS Cleveland Section Regional Conference on Hard- facing. May 16-18, Cleveland, Ohio. Sponsored by the AWS Cleveland Section and hosted by The Lincoln Electric Co. Contact: Jackie Marley, The Lincoln Electric Co., 22801 St. Clair Ave., Cleveland, OH 44117, (216) 383-2240.

Modern Furnace Brazing Course. May 17-19, Troy, Mich. Conducted by Wall Colmonoy Corp. Contact: Marianne Huesing, Wall Colmonoy Corp., 30261 Stephenson Hwy., Madison Heights, MI 48071, (248) 585-6400 ext. 248.

Laser Safety Officer Course. June 5-9, St. Louis, Mo. Sponsored by the Laser Institute of America. Contact: LIA, 13501 Ingenuity Dr., Ste. 128, Orlando, FL 32826, (407)380-1553, FAX: (407) 380-5588.

2000 Motorsports Welding School. June 19-23, August 21-25, October 30-November 3, December 11-15, Cleveland, Ohio. Conducted by The Lincoln Electric Co. For information and complete schedule, contact: Lincoln Electric Motorsports Welding School, 22801 St. Clair Ave., Cleveland, OH 44117, (216) 383-2259, FAX: (216) 383-8025.

• D1.1:2000 Structural Welding Code - - Steel. A five-day seminar sponsored by AWS. For more information, complete schedule and locations, contact: AWS Conference Dept., 550 NW LeJeune Rd., Miami, FL 33126, (800) 443-9353 ext. 223, FAX: (305) 443-1552.

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Circ le No. 12 on R e a d e r I n f o - C a r d

Quality Manual Welding Accessories ELECTRODE HOLDERS , CABLE CONNECTORS

"COPPER & STEEL GROUND CLAMPS CHIPPING HAMMERS , TANK WRENCHES

HAMMER & SOLDER ON LUGS & SPLICERS

II~IOVATIGi~I AT WORK WORI.D WIDB SAt ~ TO I)~IIR~21~O[~

3 9 6 2 P o r t l a n d S t . C o p l a y , P A 1 8 0 3 7 : T e l . : 6 1 0 - 2 6 1 - 1 9 0 0 : F a x : 6 1 0 - 2 6 1 - 0 7 4 4 E - M a i l : s a l e s @ l n w e l d c o r p o r a t i o n . c o m

Circ le No. 31 on R e a d e r I n f o - C a r d


i

~ k !

,/

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Chris Jennings, President Ramsey Welding Supply •

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Since then, machine rental has become a major aspect of the business. Chris Jennings, President, tells the story. "In the past year we have purchased more than 20 MQ Power Welders for retail and rental purposes. Our customers love them! The machines are very reliable. The safety shutdowns, thickness of the sheet metal, and even the paint color exude quality. We feel a great sense of pride when towing the equipment through town to the jobsite and 'Ramsey Welding' is boldly painted on the side:'

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MQ Power Welders feature: • Self-priming fuel systems • Built-in safety shutdowns • Silenced, weather-resistant, Iockable enclosures • Outstanding arc characteristics • Two man operation • 100% duty cycle • Fuel-efficient engines

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Atlanta o Boise = Dallas ° Houston • Newark Montreal, Canada • Manchester, UK • Rio De Janiero, Brazil • Guadalajara, Mexico


/ N E W

By Susan Campbell

¢ AWS F o u n d a t i o n A n n o u n c e s S c h o l a r s h i p R e c i p i e n t s

T he year 2000 recipients of the National Scholarships

of the American Welding Society (AWS) have been se-

lected by the Society's National Educational Scholar-

ship Commit tee .The scholarship program, which is adminis-

tered by the AWS Foundation, honors great past and present

contributors to welding technology and helps students com-

plete their undergraduate educational goals.

Meet the Recipients

H o w a r d E. A d k i n s M e m o r i a l Scholarship

R i c k L. S h e r i d a n , an AWS m e m b e r s ince 1997, was e l ec t ed to r ece ive the Howard E.Adkins Memor ia l Schol- arship. He is en ro l l ed at Montana Col lege of Mineral Sci- e n c e and Technology, w h e r e he wil l c o m p l e t e his s tudies in May 2002.

The H o w a r d E. Adk ins M e m o r i a l S c h o l a r s h i p is awarded to a full- t ime junior- or senior- level s tuden t pursuing a m i n i m u m four-year bache lo r ' s deg ree in w e l d i n g eng inee r ing or we ld ing eng inee r ing t echnology; however , p r i o r i t y wi l l be g iven to w e l d i n g e n g i n e e r i n g s tuden t s . A p p l i c a n t s mus t have m a i n t a i n e d a m i n i m u m 3.2 g rade po in t average in engineer ing , scient i f ic and technica l subjects and a 2.8 overall grade po in t average. Financial n e e d is no t r e q u i r e d to qualify. Pr ior i ty wi l l be g iven to t hose indiv iduals res id ing o r a t t end ing schoo l in Wiscons in or Kentucky. Appl ican ts must be a c i t izen of the Uni ted States and plan to a t tend an academic ins t i tu t ion loca ted wi th in t he Un i t ed S ta t e s .The $2500 award is g r an t ed on an annual basis.

Edward J. Brady Scholarship

J o n a t h a n M. S t e w a r t is the r ec ip ien t of the Edward J. Brady Scholarsh ip . He is c u r r e n t l y e n r o l l e d as a j un io r at Utah State Un ive r s i ty and is w o r k i n g t o w a r d a bachelor 's degree in weld ing eng inee r ing technology.

The Edward J. Brady Scholarship is awarded to an un- dergradua te s tuden t pursu ing a m i n i m u m four-year bach- e l o r ' s d e g r e e in w e l d i n g e n g i n e e r i n g o r w e l d i n g engi- nee r i ng technology . Pr ior i ty will be g iven to w e l d i n g en- g inee r ing s tuden t s .App l i can t s must have a m i n i m u m 2.5 overal l grade po in t average, p rov ide a le t te r o f r e f e r ence

S

Year 2 0 0 0

i n d i c a t i n g p r e v i o u s hands -on w e l d i n g e x p e r i e n c e and c o m p l e t e a 3 0 0 - 5 0 0 w o r d essay on "Why I w a n t to pur- sue a c a r e e r in we ld ing . " P r o o f o f f inanc ia l n e e d is re- q u i r e d to qua l i fy .The a p p l i c a n t mus t be a c i t i zen o f the Uni t ed States and p lan to a t t end an a c a d e m i c ins t i tu t ion in t he U n i t e d S t a t e s .The $2500 award is g r a n t e d on an annual basis.

D o n a l d F. H a s t i n g s Scholarship

Joshua D. F i e l d i n g has b e e n se lec ted to rece ive the Dona ld E Hast ing Scholarsh ip . He is w o r k i n g toward his bache lo r of sc i ence degree in we ld ing eng inee r ing at The Ohio State University.

The Dona ld E Hast ings Scholarsh ip is awarded to an u n d e r g r a d u a t e s t u d e n t p u r s u i n g a m i n i m u m four -year bache lo r ' s deg ree in we ld ing e n g i n e e r i n g or we ld ing en- g i n e e r i n g t e c h n o l o g y ; howeve r , p r io r i ty wil l be g iven to w e l d i n g e n g i n e e r i n g s tuden t s . App l i c an t s mus t have a m i n i m u m 2.5 overal l grade po in t average. P roof of financial n e e d is r e q u i r e d to qualify. Pr ior i ty wi l l be g iven to t h o s e ind iv idua l s r e s id ing o r a t t e n d i n g s c h o o l s in O h i o o r Ca l i fo rn ia .App l i can t s mus t be a c i t i zen of the Un i t ed States and p lan on a t t e n d i n g an a c a d e m i c ins t i tu t ion loca ted wi th in the Uni ted States or Canada.The $3000 award is granted on an annual basis.

John C. Lincoln Scholarship

Joshua A. D u d l e y has b e e n chosen as the r ec ip i en t o f t he J o h n C. L inco ln Schola rsh ip . He is a sen io r at The O h i o State U n i v e r s i t y and wi l l c o m p l e t e his b a c h e l o r ' s degree in we ld ing eng inee r ing in the spr ing of 2001.

The John C. Lincoln Scholarship is awarded to an un- dergradua te s tuden t pur su ing a m i n i m u m four-year bach- e l o r ' s d e g r e e in w e l d i n g e n g i n e e r i n g o r w e l d i n g engi- n e e r i n g technology . Pr ior i ty wil l be g iven to we ld ing en- g inee r ing s tuden t s .App l i can t s must have a m i n i m u m 2.5 overa l l g rade p o i n t average , and p r o o f of f inanc ia l n e e d is r e q u i r e d to qua l i fy .The app l i can t must be a c i t i zen of the Uni ted States and p lan to a t t end an academic institu- t ion loca ted wi th in the Uni ted States .The $2500 award is g ran ted on an annual basis.

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Scholarship Recipients

- - continued from page 55

Praxair I n t e r n a t i o n a l Scholarship

The Praxair International Schol- arship has been awarded to W e s l e y W. D o n e t h . He is enrol led in Ferris State University 's Welding Engineer- ing Technology program.

The Praxair International Schol- arship is awarded to an undergraduate s tudent pursuing a min imum four-year bachelor 's degree in welding engineering or welding engineering technology; however , pr ior i ty will be given to welding engineering s tudents . Appl ican ts must have a minimum 2.5 overall grade point average, and proof of financial need is requi red to qualify. The appl icant must be a citizen of the United States and plan to attend an academic institu t ion loca ted wi th in the United States or Canada.The $2500 award is granted on an annual basis.

A i r g a s - T e r r y J a r v i s M e m o r i a l S c h o l a r s h i p

The Airgas - Terry Jarvis Memor- ial Scholarship w i n n e r is B r i a n F. M u e n c h a u . He holds an associate 's degree in applied science of welding technology from Belleville Area Col- lege. He is current ly enrol led at Fer- ris State University in the welding en- g ineer ing t echno logy program and expec t s to earn his degree in May 2001.

The Airgas - Terry Jarvis Memor- ial Scholarship is awarded to a full- time undergraduate pursuing a minimum four-year bachelor ' s degree in welding engineer ing or welding en- g ineer ing technology; however , priori ty will be given to weld ing engineer ing s tudents in te res ted in pursuing a career with an industrial gas or we ld ing e q u i p m e n t distributor. Applicants must have a minimum 2.8 overall grade poin t average, wi th a 3.0 grade point average in engineering courses. Financial need is not requi red to qualify. Priori ty will be given to those individuals residing or attending schools in the states of Al- abama, Georgia or Florida.The applicant must be a ci t izen of the United States and plan to a t tend an academic ins t i tu t ion loca ted wi th in the United States or Canada.The $2500

award is $2500 is granted on an annual basis.

R o m a n F. a n d Li lHan F. A r n o l d y S c h o l a r s h i p

D a r i n C. N i e l s e n has been awarded the Roman E and Lillian E. Arnoldy Scholarship. He is a junior at Utah State University working toward a bachelor 's degree in welding engineer ing technology. He expects to graduate in 2002.

The Roman E and Lillian E. Arnoldy Scholarship is awarded to a full-time undergraduate student pursuing a minimum four-year degree in a welding program at an accredi ted university. Appl icants must have a minimum 2.0 overall grade point average.Applicants must be employed at least e ight hours a week and /o r par t ic ipa te in a univers i ty work / study program. The appl icant must be a citizen of the United States and plan to a t tend an academic institution located within the United States. The $2500 award is granted on a regular basis.

The deadl ine for the above scholarships is January 15 for the following fall term. Funding is made available June 1-May 31.

O t h e r A v a i l a b l e S c h o l a r s h i p s

The Foundat ion also offers the Mi l l e r E lec t r i c IYSC S c h o l a r s h i p . To b e c o m e eligible for this scholarship, the applicant must compe te in the national VICA USA Skills Compe- tition for welding and advance to the AWS Weld Trials held biannually at the AWS Internat ional Welding and Fabricating Exposit ion and Conven- tion.Also available are Dis t r ic t Schol- a r sh ips , which are awarded through AWS Distr icts .The Deadline for Dis- trict Scholarships isApril 1, for the following fall t e rm.There is also a student loan program available.

Further I n f o r m a t i o n For fur ther informat ion about

qual i f icat ions regarding these AWS Foundation scholarship programs or to reques t an appl ica t ion package, call the AWS Foundat ion office at (800) 443-9353 ext. 461. •

S E C T I O N E V E N T S

C A L E N D A R

•DELAWARE All meetings are held the second Wednesday of each month.

MAY 10 Act iv i ty: Student/Vendor Night and Welding Truck Competi t ion at Del- castle Technical High School,Wilm- ington, Del.

• M O B I L E Meetings will be held on the third Thursday of each month f rom Septem- ber through May. Unless otherwise noted, social hour begins at 6:00p.m., dinner at 6.'30p.m. and the evening's speaker at 7:30p.m.

MAY 16 Ac t i v i t i e s : End-of-year activities. Elect ion of officers, District Con- ference recap, presentation of Sec- t ion scholarships and awards, r ecogn i t ion of past cha i rmen and special service members.

• N O R T H E A S T MISSISSIPPI

MAY 12 A c t i v i t y : T h e Section will hold its dinner meeting at Bill &Jim's inAb- erdeen, Miss. It will be Ladies' Night and Officer Installation Night.

• SANTA CLARA VALLEY Unless otherwise noted, sign-in for the meetings is 6.'30 to 7:00p.m., dinner fol lows at 7:00 to 8:00p.m. and the evening's presentation is f rom 8.'00 to 9:00p.m. at Harry's Hofbrau in San Jose.

MAY 9 Speakers: Sco t t F u n d e r b u r k and D w a y n e Miller . A f f i l i a t i o n : The Lincoln Electr ic Co., Cleveland, Ohio. Topic: The James E Lincoln Welding Foundat ion Scholarships and Awards.

561 MAY2000

• B a t o n R o u g e S e c t i o n a n d L i o n s Club T e a m U p

M - e m b e r s o f t h e A m e r i c a n

W e l d i n g S o c i e t y ' s B a t o n . R o u g e S e c t i o n a n d a n d

m e m b e r s o f t h e B a t o n R o u g e D o w n t o w n L ions C l u b r e c e n t l y t e a m e d u p to h e l p a local family in need .

L a w r e n c e D e J o h n , a m e m b e r o f t h e D o w n t o w n Lions C l u b a n d a r e t i r e d p l u m b i n g c o n t r a c t o r , was a p p r o a c h e d to h e l p a family in n e e d o f a r a m p for a w h e e l c h a i r pa t i en t . T h e pa t i en t , Mrs. Frank Stabiler, h a d to b e t a k e n to r e h a b i l i t a t i v e t h e r - a p y t h r e e t i m e s a day .At t h e t i m e D e J o h n w a s a p p r o a c h e d , t h e family was us ing a r a m p tha t h a d to b e p u t in p l a c e e a c h t i m e t h e y w o u l d l eave t h e h o u s e a n d a g a i n w h e n t h e y r e t u r n e d . It w a s q u i t e an in- c o n v e n i e n c e .

D e J o h n p r e s e n t e d t h e r e q u e s t fo r a r a m p to t h e L ions C lub , a n d t h e m e m b e r s v o t e d to t ake o n t h e p r o j e c t . Af t e r m u c h d i s c u s s i o n o f " h o w to" and " h o w much," O.J.Tem- p l e t , w h o is a L ions C l u b m e m b e r as we l l as AWS Di s t r i c t 9 Di rec to r , s u g g e s t e d t h i s w o u l d b e a g o o d Welding for Communities p r o j e c t for t he C h a t t a n o o g a AWS Sect ion .

Wi th t h e dec i s ion m a d e for t h e C h a t t a n o o g a Sec t i on to s p e a r h e a d t he p ro j ec t , Sec t ion m e m b e r B o b b y Wi l l i ams , f a b r i c a t i o n f o r e m a n o f P l a n t M a c h i n e Works , a l oca l ma- c h i n e s h o p a n d f a b r i c a t i o n c o m - pany, d i s c u s s e d t h e p r o j e c t w i t h h i s bos s , C l a u d e Barber , o w n e r o f t h e c o m p a n y . B a r b e r o f f e r e d n o t o n l y to d o t h e f a b r i c a t i o n b u t to also d o n a t e t he ma te r i a l s and l a b o r n e c e s s a r y to f ab r i ca t e t h e d e c k and r a m p f rame.

T h e d e c k was d e s i g n e d at a 3- in. a n g l e a n d t h e r a m p at a 2~-in. a n g l e . T h e c o m b i n e d l e n g t h o f t h e d e c k a n d r a m p is 13 i f .Af t e r fabr i - ca t ion , Ba rbe r and Wil l iams h a d t he f r a m e d e l i v e r e d to a n d i n s t a l l ed at t h e S t a b i l e r h o m e . A f t e r t h e d e c k a n d r a m p w e r e ins ta l l ed , t h e Lions C l u b m e m b e r s i n s t a l l e d ~A-in. ply- w o o d to t he f rame.

Mr. a n d Mrs. S t a b i l e r w e r e t h r i l l e d w i t h t h e o u t c o m e . A f t e r t e s t i n g t h e r a m p , Mr. S tab i l e r com- m e n t e d , " t h i s r a m p is so s t r o n g , I c o u l d r u n a b u l l d o z e r o n it and n o t worry." •

• C h a t t a n o o g a C e l e b r a t e s C a r e e r and T e c h n i c a l E d u c a t i o n

c h a t t a n o o g a , T e n n . , h i g h s c h o o l s s p e n t a w e e k in F e b r u a r y c e l e b r a t i n g

C a r e e r a n d T e c h n i c a l Educa- t i o n W e e k . H a m i l t o n C o u n t y s choo l s a d m i n i s t r a t o r Dr .Andy H o l d t sa id th i s w e e k gave stu- d e n t s t h e c h a n c e to ge t o u t of t h e c l a s s r o o m a n d e n t e r work- s i t e s to s ee fo r t h e m s e l v e s " w h a t r ea l ly g o e s o n in t h e workp lace . "

As p a r t of t h e c e l e b r a t i o n , ABB A l s t o m Power , f o r m e r l y C o m b u s t i o n E n g i n e e r i n g , in- v i t e d m o r e t h a n 2 0 0 w e l d i n g s t u d e n t s to t o u r i t s p l a n t . T h e c o m p a n y e m p l o y s o n l y a b o u t 10% as m a n y e m p l o y e e s as i t d i d 25 y e a r s a g o . " I t ' s a t h r i l l t o s e e p e o p l e i n t e r e s t e d in w e l d i n g and o u r b u s i n e s s a f t e r w h a t w e ' v e b e e n th rough , " said Rob Sentel l , ABB's d i r e c t o r of h u m a n r e s o u r c e s in C h a t t a n o o g a . A f t e r d e c a d e s of c u t t i n g staff, c o m p a n i e s l ike ABB are n o w a d v e r t i s i n g for w e l d e r s to h a n d l e t h e in- c r e a s i n g a m o u n t o f w o r k t h e y are r e c e i v i n g , as w e l l as to h e l p r e p l a c e re- t i r ing w o r k e r s .

S t u d e n t s w e r e i m p r e s s e d to see t h e ac tua l o p e r a t i o n o f t h e ABB p l a n t . T h e y r e c e i v e d a fu l l t o u r o f t h e o p e r a t i o n , f r o m h o w t h e g e n e r a t o r s a n d b o i l e r s w o r k to X-ray o f w e l d s to t h e f ina l p r o d u c t . S t u d e n t Mack R o g e r s s a id , " I t w a s f u n to w a t c h t h e way t h e p i p e w a s p u t t o g e t h e r f r o m t h e be- g i n n i n g to t h e end . I w i s h I c o u l d h a v e s t a y e d t h e r e all day to r ea l ly ge t a g o o d look at t h e ope ra t ion . "

V o c a t i o n a l s t u d e n t s h a v e o f t e n b e e n o v e r l o o k e d in t h e pa s t in favor of t h o s e w h o are c o l l e g e - b o u n d . But r e c e n t l y , t h e r e h a s b e e n a n u p s w i n g in m a n u f a c t u r i n g a n d c o n s t r u c t i o n , s o s t u d e n t s g r a d u a t i n g f r o m v o c a t i o n a l p r o g r a m s are s u d d e n l y in d e m a n d . W i t h w e l d e r s in s u c h h i g h d e m a n d , qual- i f ied s t u d e n t s n o w h a v e to c h o o s e w h e t h e r to a c c e p t a p o s i t i o n r i g h t o u t o f h i g h s c h o o l o r to go o n a n d c o n t i n u e t h e i r e d u c a t i o n . W i t h a c r i t i c a l s h o r t a g e o f w e l d e r s , e m p l o y e r s s u c h as B u r n e r S y s t e m s I n t e r n a t i o n a l in C h a t t a n o o g a are h i r i n g qua l i f i ed w e l d e r s s t r a igh t o u t o f h i g h schoo l ; o t h e r s w h o p r e v i o u s l y d e m a n d e d f u r t h e r t r a i n i n g are n o w o f f e r i ng t r a i n i n g t h e m - se lves o r a re s e t t i n g u p a p p r e n t i c e p r o g r a m s to e n t i c e y o u n g w e l d e r s . Stu- d e n t s w h o c h o o s e to c o n t i n u e t h e i r e d u c a t i o n are b e i n g m a d e aware of t h e m a n y s c h o l a r s h i p o p p o r t u n i t i e s t h r o u g h t h e A m e r i c a n We ld ing Society.

T h e e v e n t s d u r i n g C a r e e r a n d T e c h n i c a l E d u c a t i o n W e e k h e l p e d s tu- d e n t s s ee t h e m a n y o p p o r t u n i t i e s a c a r e e r in w e l d i n g h o l d s f o r t h e m . A l - t h o u g h t h e y w e r e s h o w n t h e b r i g h t f u t u r e ava i l ab le to t h e m w i t h a c a r e e r in w e l d i n g , t h e y w e r e a lso e n c o u r a g e d to s t u d y ha rd . " T h e r e is d e f i n i t e l y a s h o r t a g e o f w e l d e r s in t h e sk i l l ed areas ," sa id D a v i d H a m i l t o n , a c e r t i f i e d w e l d i n g i n s t r u c t o r at S e q u o y a h V o c a t i o n a l T e c h n i c a l S c h o o l . " T h e w e l d i n g o f t o d a y is n o t a l w a y s a d i r t y job , a n d it c a n p a y v e r y we l l . Bu t i t a l so requ i r e s s t u d e n t s w i t h s t r o n g m a t h a n d c o m m u n i c a t i o n s [skills]." •


A W S P U B L I C A T I 0 N

• N e w M e t h o d o f W e l d i n g Part icu la te S a m p l i n g N o w Avai lab le

S

The American Welding Society (AWS) has comple ted the latest edi t ion of Method f o r Sampling Airborne Particulates Generated by Welding and Allied Processes (AWS F1.1 : 1999).This ANSI-approved document illustrates the p roper technique for sampling welding fumes in the workplace with a special emphasis p laced on the pos i t ion ing and cal ibrat ion of sampling equipment.

Method for Sampling Airborne Particulates Generated by Welding and All ied Processes is divided into nine sect ion with detai led information on fume concen t ra t ion exposure condi t ions, sampling equ ipmen t and condi- t ioning and sampling techniques.This edition is 12 pages, measures 8~ x 11 and is softbound.The list price is $32; $24 for AWS members.

• Test S p e c i m e n S t a n d a r d for T h e r m o p l a s t i c s P u b l i s h e d

The latest edi t ion of Specification f o r S tandardized Ultrasonic Weld- ing Test Specimen f o r Thermoplast ics (AWS G. 12M/G 1.2:1999) has been published by AWS.This ANSI-approved specification covers a wide range of information on thermoplas t ic welding and was deve loped under the guidance of the AWS G1 Commit tee on Joining of Plastics and Composites in response to the plastics industry's demand for a detailed reference document. The speci f ica t ion can be used for numerous invest igat ions including, but not l imited to, thermoplas t ic ultrasonic weldabil i ty studies, thermoplas t ic ultrasonic welding optimizations, as well as scientific studies on the ultrasonic welding of thermoplastics.

Specification f o r S tandardized Ultrasonic Welding Test Specimen f o r Thermoplastics is divided into eight sections, which include figures and definitions related to the geometry of standard samples and preparations, welding, data recording and testing procedures .The specif icat ion also includes annexes. Specification f o r Standardized Ultrasonic Welding Test Specimen for Thermoplastics is $32; $24 for AWS members. •

Copies can be ordered by call ing AWS Cus tomer Service at (800) 334- 9353, (305) 334-9353 outside the United States, Monday through Friday, 8 a.m. to 5 p. m. EST, or through the AWS Web site at www. aws. org. Addi- t ional information on AWS's programs and publicat ions can also be f o u n d on the Web site. •

• AWS E m p l o y e e A w a r d e d b y Las Vegas S e c t i o n A WS staf f member- Rhenda Mayo, assistant director of member~customer services, right, was surprised to recieve the Life Saver o f the Year f r o m the Nevada Section. The award was presented to her by Wendy Reeve, left, A WS managing director o f professional services and Jack Compton, Dis- trict 21 Deputy District Director, in August at the Leadership Sympo- sium in Miami.

• CAN WE TALK? The Welding Journal staff encourages

an exchange of ideas with you, our readers. If you'd like to ask a question, share an idea or voice an opinion, you can call, write, e- mail or fax. Staff e-mail addresses are listed below, along with a guide to help you inter- act with the right person.

Pub l i sher J e f f Weber [email protected] General Management, Reprint Permission, Copyright Issues

Edi tor A n d r e w Cul l i son [email protected] Article Submissions

Features Editor Mary R u t h J o h n s e n [email protected] Feature Articles

Assis tant Edi tor Susan Campbe l l [email protected] Society News

Assistant Editor Tim Heston [email protected] New Products

Managing Edi tor Chr is t ine Tarafa [email protected] Design and Production

Product ion Assistant Zaida Chavez [email protected] Design and Production

Publications Secre tary Karleen Bourne

[email protected] General Information

Adver t i s ing Sales Di rec to r Rob Saltzstein

[email protected] Advertising Sales

Advertising Production Manager Col leen Beem

[email protected] Advertising Production

Adver t i s ing Coordinator Lea Garr igan

[email protected] Production and Promotion

Peer Review Coordinator D o r e e n Kubish

[email protected] Peer Review of Research Papers

Welding Journal Dept . , 550 N.W. LeJeune Rd., Miami, FL 33126, (800) 443-9353 ext. 348, FAX (305) 443-7404.

58] MAY 2000

S A F E T Y A N D H E A L T H T 0 P I C S

• F a l l i n g O b j e c t s Fact S h e e t No . 10

I n t r o d u c t i o n

Welding, cu t t ing and assoc ia ted p roces se s of ten take p l a c e in a reas w h e r e fa l l ing o b j e c t s may be p r e s e n t . Fal l ing o b j e c t s may se r ious ly in ju re o r kill. Fal l ing ob- jec ts are c o m m o n p r o b l e m s on c o n s t r u c t i o n and demo- l i t ion s i tes o f all k inds , f r o m b u i l d i n g s to br idges , and are also of ten a p r o b l e m dur ing m a i n t e n a n c e work.

H o w t o P r o t e c t against Falling Objects

• Wear a p p r o v e d head and foot p ro tec t ion . • Be alert and aware of your total w o r k e n v i r o n m e n t

and any p o s s i b l e o v e r h e a d o b j e c t s b e f o r e you s tar t working .

• Place a safety net or equivalent be low overhead work. • Fo l low safe w o r k p r a c t i c e s w h e n w o r k i n g b e l o w

ove rhead activit ies. • Not i fy o the r s o f ove rhead w o r k and any chang ing

job condi t ions . • R e m e m b e r , a w e l d i n g h e l m e t o r g o g g l e s r e s t r i c t

v i s ion and may p r e v e n t tak ing the ac t ion n e c e s s a r y to avoid falling objects .

• Post areas w h e r e falling ob jec t s are a hazard.

H o w t o Prevent Falling O b j e c t s

• Be ce r ta in that mater ia l be ing w e l d e d or cut is se- cu red f rom falling.

• Do no t p e r m i t loose ob jec t s near the edge of overhead s t ruc tures .

• Cover f loo r and wal l open ings . • Use toe boards wi th guardrails .

• Do no t kick, t h r o w or push anything off ove rhead structures - - this includes electrode stubs and scrap metal.

• Do n o t c r e a t e fa l l ing o b j e c t s for o the r s ; be a le r t t o all your act ions.

I n f o r m a t i o n S o u r c e s

Amer ican Nat ional Standards Ins t i tu te (ANSI). Safe ty in We ld ing a n d C u t t i n g , Z49.1. Avai lab le f r o m Amer i - can A m e r i c a n W e l d i n g Socie ty , 550 N W LeJeune Rd., Miami, FL 33136.

Na t iona l I n s t i t u t e for O c c u p a t i o n a l Safety and Health. Safe ty a n d Hea l th in A r c Welding a n d Gas Weld- i ng a n d C u t t i n g , NIOSH P u b l i c a t i o n No. 7 8 - 1 3 8 . Na- t iona l I n s t i t u t e for O c c u p a t i o n a l Safety and Hea l th , Cincinnat i , Ohio.

O c c u p a t i o n a l Safety and H e a l t h A d m i n i s t r a t i o n (OSHA). Code o f F ed er a l R e g u l a t i o n s , T i t l e 29 Labor, Chap te r XVII, Parts 1901.1 to 1910.1450, Orde r No. 869- 019-00111-5 .Ava i l ab le f r o m S u p e r i n t e n d e n t o f Docu - m e n t s , U.S. G o v e r n m e n t P r i n t i n g O f f i c e , W a s h i n g t o n , DC 20402.

Mine Safety and Heal th Adminis t ra t ion (MSHA). Code o f Federal Regu la t ions ,T i t l e 30 Mineral Resources , Parts 1 - 1 9 9 . A v a i l a b l e f r o m S u p e r i n t e n d e n t o f D o c u m e n t s , U.S. G o v e r n m e n t P r i n t i n g Of f i ce , W a s h i n g t o n , DC 20402. •

The Safety and Health Fact Sheets, 2nd ed., cover all aspects of safety and health applicable to welding and cutting. The Fact Sheets include 20pages on subjects such as fumes and gases, radiation, noise and electrical hazards. Compiled in 1998. Price for AWS members is $2 4; nonmembers, $32. Copies of Safety and Health Fact Sheets can be ordered by calling AWS Customer Ser- vice at (800) 334-9353, or (305) 443-9353 ext. 280 outside the United States, Monday through Friday, 8 a.m. to 5 p.m. Eastern Standard Time.

¢ L o u i s i a n a G o v e r n o r P r o c l a i m s W e l d i n g W e e k f o r t h e State

O n February 15, G o v e r n o r M.J., "Mike" Foster , Jr., o f f i c ia l ly p ro- c l a i m e d t h e w e e k o f Apr i l 2 3 - 2 9 as Nat ional Welding Week in the state of Louisiana.

The Proc lamat ion states: " W h e r e a s , w e l d i n g is a p rofes -

s ion r e q u i r i n g c o n s i d e r a b l e t ra in ing and spec ia l ized study; further , the ap- p l ica t ion of that t ra ining and special- i zed s tudy is c r i t i ca l to t he g e n e r a l w e l l b e i n g o f t h e c o u n t r y and cal ls for a c o n s t a n t s t r e a m of o p e r a t o r s , d e s i g n e r s , i n s p e c t o r s , e n g i n e e r s , t e a c h e r s , and sc i en t i s t s f r o m o u r schools and univers i t ies ; and

W h e r e a s , A m e r i c a n Weld ing So- c i e ty S e c t i o n s and Dis t r i c t s w i s h t o

r e m i n d the p u b l i c abou t the c r i t i ca l i m p o r t a n c e o f weld ing; and

W h e r e a s , the Amer ican Welding Soc i e ty ' s Dis t r i c t s 9 and 17 e n c o u r - age the pa r t i c i pa t i on in a pub l i c ser- v ice program, Welding for Communi - t ies , tha t f o l l o w s in t he t r a d i t i o n o f o t h e r p r o f e s s i o n s ' s e r v i c e s for t h e c o m m o n good; and

W h e r e a s , W e l d i n g for C o m m u - ni t ies is the annual pub l i c c a m p a i g n of the Amer ican Welding Socie ty that is c e l e b r a t e d d u r i n g N a t i o n a l Weld- ing Week.

T h e r e f o r e , I, M.J. "Mike" Foster, Jr., G o v e r n o r of the state of Louisiana do he reby proc la im April 23-29, 2000 as N a t i o n a l W e l d i n g W e e k in the state of Louisiana, and urge all ci t izens t o r ecogn ize the hard w o r k and dedi- cat ion of all we lders in our state."

Fos t e r i s sued this P r o c l a m a t i o n in r e c o g n i t i o n o f t he hard w o r k and d e d i c a t i o n o f t h e w e l d e r s in h is s t a te .Th is is s o m e t h i n g Fos te r real ly k n o w s abou t . He may be o n e o f t he f e w g o v e r n o r s in th is c o u n t r y w h o at one t ime w o r k e d as a p ro fes s iona l we lder . •


AWS WELCOMES N E W S U P P O R T I N G C O M P A N I E S

N e w S u p p o r t i n g C o m p a n i e s

Aerocell Structures, Inc. 115 Centennial Dr. Hot SpringsAR 71913

Airgas Southwest 319 N.E. 23 Street Fort Worth,TX 76106

Auciello Iron Works, Inc. 560 Main St. Hudson, MA 017549

N e w Educat iona l Inst i tut ions

Canyon Owyhee Service Agency 21985 Dixie River Rd. Caldweil, ID 83605

Clarion County Career Center 1976 Career Way Shippenville, PA 16254

Washington Local Schools 5719 Clegg Dr. Toledo, OH 43613

ABB Alstom Power Peru Calle Camino Real 166 Urb. San Francisco de Ate Lima 3 Peru

• M e m b e r D u e s A d j u s t m e n t

T h e AWS Board of Directors, acting on the recommendat ions made by the Membership Committee, approved a dues adjustment to $75 for the "Reg- ular Member" classification effective June 1, 2000.

Upon joining and every third membersh ip year, Regular Members clues will include an expanded publ ica t ion cho ice of e i the r the latest Welding Handbook, Welding Metallurgy,Jefferson's Welding Encyclopedia, Solder- ing Handbook or the Design and Planning Manual for Cost-Effective Weld- ing upon request. In addition,AWS members receive a monthly subscription to the award-winning Welding Journal, as well as b imonthly issues of The American Welder supplement .AWS-cer t i f ied pe r sonne l also rece ive quar- terly issues of Inspection Trends magazine.

AWS members enjoy access to widely respected technical information in the materials joining industry at discounted rates. Members-only discounts apply to AWS technical publicat ions, as well as to top-notch cert if ications, conferences and other educational offerings. Members also benefit from net- working opportuni t ies at local Section meetings and at the AWS Exposition. Commenc ing June 1,AWS members will be able to choose b e t w e e n two value-added membership package offerings, the Gold and the Platinum Mem- bership Packages, for modest fees.And, in the near future,AWS members will enjoy members-only access to special information and services on the AWS Web site, www.aws.org. •

• Sus ta in ing M e m b e r C o m p a n y

O tis Elevator Co. is the

f ac tu re r o f e leva tors , wor ld ' s leading manu-

esca la tors and o t h e r peop l e - mov ing e q u i p m e n t . Otis produces e l eva to r s for low-r ise

applicat ions up to seven f loors wi th holed and holeless hydraulic systems, mid-rise and high-r ise e l eva to r systems and heavy f re igh t e l eva to r s .The c o m p a n y also sells an e l eva to r for pr iva te h o m e s . T h e company ' s escala- tors and horizontal t ransportat ion systems are designed primarily for commercial use wi th high foot traffic requirements .

Otis's horizontal transportation systems offer a complete range of automated people movers capable of moving a few hundred to several thousand passen- gers per hour from a few hundred feet to several miles.

Otis Elevator Co. will tailor a maintenance service system specifically to the customer's environment and equipment. •

¢ S u s t a i n i n g Member Dues Update

E f f e c t i v e immediately, the following adjustments have been im- p l e m e n t e d for AWS Sustaining Member Company Memberships:

Dues: The annual dues are $700, domest ic ; $800, international; plus a $500 initiation fee. In- cluded are up to ten members allo- cated under the annual fee.

Benefits: Sustaining Member benefits include 1) the AWS library of codes and standards (a $5500 value), wi th subsequent revisions; 2) tenAWS individual memberships for employees or cus tomers ; 3) usage of the AWS Sustaining Com- pany Member logo; 4) an annual bound volume of the Welding Jour- nal; 5) company recognit ion in the Welding Journal and at the AWS Expo; 6) free hyper l ink f rom the AWS Web site; and 7) a Sustaining Company Member wall plaque.

For informat ion on becoming an AWS Sustaining Member Com- pany, contact Martha Concepcion , M e m b e r s h i p / C u s t o m e r Services Dept.,AWS, 550 LeJeune Rd., Miami, FL 33126; (800) 443-9353 ext. 259; FAX (305) 443-7559. •

• AWS MEMBERSHIP

M e m b e r As o f G r a d e s A p r i l 1, 2000

Sustaining .................................. 336

Member ................................ 43,408

Transitional .................................. 50

Student .................................... 4,906

Honorary ...................................... 29

Life ........................................... 1,357

Retired ........................................ 260

Total ............... 50 ,346

60 [ MAY 2000

• S t u d e n t P r o p o s e r s

AWS T-shirts h a v e b e e n a w a r d e d to t h e fo l l owing s t u d e n t s for recru i t - ing n e w AWS S t u d e n t M e m b e r s be- t w e e n O c t o b e r 1, 1999 to March 1, 2000:

• E a r l S p a l d i n g , Willamette Valley, 13 • A n d r e w J o s e p h , Columbus, 10 • T y l e r S t o r e y , Utah, 9 • K a r l S a m u e l s o n , Albuquerque, 6 • R i c k y W a l b u r n , Twin Tiers, 3 • C h e C h a n c y , L.A./Inland Empire, 2 • R o b e r t C a r t e r , Columbus, 2 • L o r i E c k e r t , Syracuse, 2 • A l l a n T o m n i t z , J . A . K . , 2 • A v e r y B a r r o w s , Twin Tiers, 2 • D a v i d S e a r l e s , Twin Tiers, 2 • C. J . L u c e r o , Portland, 2

One T-shirt is awa r ded to s t u d e n t m e m b e r s for r e c r u i t i n g t w o n e w stu- den t m e m b e r s . T h e r e is n o limit to the n u m b e r of shirts tha t can be earned. •

• C l e v e l a n d to H o l d H a r d f a c i n g C o n f e r e n c e

The AWS Cleve land Sec t ion Re- g iona l C o n f e r e n c e o n Hardfac ing , w h i c h wil l b e h o s t e d b y T he Linco ln Electric Co.,will be he ld on May 16-18.

For f u r t h e r i n fo rma t ion and regis- t ra t ion, c o n t a c t Jackie Marley, T he Lin- co ln Elect r ic Co., 22801 St. ClairAve. , Cleveland, OH 44117, or call (216) 383- 2240. •

• A n n o u n c e Y o u r Sect ion ' s Activit ies

S t i m u l a t e a t t e n d a n c e at your Sec- t ion ' s mee t ings and t ra in ing p rograms wi th free listings in the Sect ion Meet- ing Calendar c o l u m n of Society News.

Useful i n f o r m a t i o n i nc ludes y o u r Sect ion name; act ivi ty date , t ime and loca t ion; speake r ' s name , tit le, affilia- t i on and sub jec t ; a n d n o t i c e s o f gol f ou t ings , seminars , contes ts and o the r special Section activities.

If some of your m e e t i n g p lans are sketchy, s e n d t h e n a m e a n d p h o n e n u m b e r of a pe rson to contact for more information.

Send you r n e w c a l e n d a r to Susan C a m p b e l l , Ass i s t an t Editor, W e l d i n g Journa l Dept.,AWS, 550 N.W. LeJeune Rd., Miami, FL 33126; FAX: (305) 443- 7404. •

• AWS O f f e r s N i n e - Y e a r CWI R e c e r t i f i c a t i o n C o u r s e

T h e Amer i - c a n W e l d i n g Soci- e ty ' s (AWS) Educa- t i on D e p a r t m e n t is n o w of fe r ing a six- day CWI n i n e - y e a r r e c e r t i f i c a t i o n course .Th i s c o u r s e e l i m i n a t e s t h e n e e d for CWIs to t ake t h e p h y s i c a l test , and it sat isf ies t he 80-hour cont in- u i n g e d u c a t i o n requ i r ed for recert if i-

c a t i o n . T h e course , Members o f the nine-year recertification class held in h o w e v e r , is n o t Miami in April. Instructor Ken Coryell, wearing light- easy, and it cons i s t s colored slacks, is in the center o f the photograph. of ve ry long hours , M o n d a y t h r o u g h Fr iday f r o m 8 a.m. to 10 p .m. a n d 8 a.m. to 5 p .m. o n Satur- day. Dean Droddy, QA/QC m a n a g e r at Na t iona l Riggers a n d Erec tors , Det ro i t , Mich. , a t t e n d e d t he f irst c o u r s e and said, "The h o u r s w e r e difficult , bu t t h e al- t e r n a t i v e is to h o l d t h e c o u r s e o v e r a t w o w e e k p e r i o d i n s t e a d o f s ix days, and it w o u l d b e h a r d to get away for t ha t a m o u n t of time."

Six ty-four CWIs s i g n e d u p to a t t e n d t h e i n a u g u r a l c o u r s e , w h i c h was s c h e d u l e d for Beaumont ,Tex . , Feb rua ry 28 t h r o u g h March 4. Because only ha l f t h a t n u m b e r of r e s p o n s e s was e x p e c t e d , N a n c y D 'Azevedo , p r o d u c t deve lop- m e n t c o o r d i n a t o r for t he Educa t ion D e p a r t m e n t w h o ove r sees the recert i f ica- t i o n c o u r s e s , h a d to r e c r u i t a n o t h e r i n s t r u c t o r a n d f i nd a n o t h e r h o t e l w i t h t he n e c e s s a r y faci l i t ies in Orange ,Tex . Ron T h e i s s was b r o u g h t in as ins t ruc - to r for t he Orange class, and Ken Coryel l i n s t r u c t e d t he B e a u m o n t g roup .

T h e c o u r s e o f fe r s m o r e t h a n jus t l e c t u r e s . A t o u r of an NDE si te is con - d u c t e d , a n d t h e r e is a lo t o f class p a r t i c i p a t i o n a n d w o r k i n g in g roups . Each a t t e n d e e is a sked to b r i n g d o c u m e n t a t i o n o f r ea l -wor ld p r o b l e m s t h e y h a v e e n c o u n t e r e d d u r i n g t h e i r c a r e e r for a g r o u p p r o b l e m - s o l v i n g sess ion. D u r i n g class, t he a t t e n d e e s b r e a k in to g roups , p i ck a p r o b l e m and solve it as a g roup . Brad Hart , a CWI at C h r o m a l o x , f o u n d it " t r e m e n d o u s l y i n t e r e s t i n g and infor- m a t i v e to so lve t h e p r o b l e m s . W i t h s u c h a va r i e ty of e x p e r t s in t h e g r o u p , i t w as i n t e r e s t i n g to see if t h e o t h e r s sha re you r views." David J o h n s o n o f PDM Bridge, Eau Cla i re ,Wis . , a lso a g r e e d t h e g r o u p p r o b l e m s w e r e a h i g h l i g h t o f t he c o u r s e . J o h n s o n sa id , "The c o u r s e is w o r t h t ak ing b e c a u s e it is m o r e t h a n just r ev i ewing the f u n d a m e n t a l and th ings you have n e v e r even used .The com- b i n e d e x p e r i e n c e in o u r g r o u p was m o r e t h a n 300 years! Some of t he p r o b - lems w e r e ve ry in te res t ing , and you like to see if you w o u l d have so lved t h e m t he same way."

S ince t h e in i t ia l Nine-Year R e c e r t i f i c a t i o n C o u r s e was h e l d in Texas, an- o t h e r was he ld atAWS h e a d q u a r t e r s in Miami o n A p r i l 3 t h r o u g h 9. O n c e again, Ken Coryel l was t he ins t ruc tor . Coryel l said h e r ece ived a lot of f eedback f rom t h e f i r s t g r o u p a n d is sti l l in t h e p r o c e s s o f " t w e a k i n g t h e c u r r i c u l u m T T h e f e e d b a c k ha s b e e n v e r y pos i t i ve , so I ' m rea l ly jus t f ine t u n i n g a n d m a k i n g m i n o r adjus tments ," h e said.

T he c o u r s e p rov ides f r e e d o m f rom the exam, and a t t e n d e e s r ece ive t h e i r AWS Cer t i f ica te of C o m p l e t i o n o n t he final day of t he c o u r s e . T h e CWI Certifi- c a t i o n r e n e w a l wal l ce r t i f i ca t e a n d wa l l e t ca rd wil l b e g i v e n o n t he f inal day o f t h e c o u r s e c o n t i n g e n t u p o n a c u r r e n t eye e x a m r e q u i r e m e n t of s e v e n m o n t h s p r io r to the da te of recer t i f ica t ion .

T h e cos t o f t h e Nine-Year R e c e r t i f i c a t i o n C o u r s e is $1295 a n d i n c l u d e s t ex tbooks , r ece r t i f i ca t ion fee and a three-yearAWS m e m b e r s h i p . F u r t h e r infor- m a t i o n and a s c h e d u l e of u p c o m i n g c o u r s e s and w h e r e t h e y wil l be he ld c an be o b t a i n e d by cal l ing Nancy D'Azevedo,AWS Educa t ion D e p a r t m e n t , at (800) 443-9353 ext. 477. •


T E C H N I C A L C O M M I T T E E

M E E T I N G S

AII AWS technical committee meetings are open to the public. Persons wishing to attend a meeting should contact the staff secretary of the committee, as listed below, at AWS, 550 N.W. LeJeune Rd., Miami, FL 33126, telephone (305) 443-9353.

May IO-11,A2C Subcommit tee on Symbols. Mobile, Ala.Standards prepara t ion meet ing. Staff contact : S. P. Hedrick.

May 11,A2 Committee on Definitions and Symbols. Mobile,Ala. Standards prepara t ion meet ing. Staff contact : S. P. Hedrick.

May 11-12, A2B Subcommit tee on Definit ions. Mobile, Ala. Standards prepara t ion meet ing. Staff contact : S. E Hedrick.

• T e n n e s s e e G o v e r n o r H o n o r s W e l d e r s

Governor Don Sundquist ofTen- nessee honored the welding profession by procla iming April 23-29 as Welding Week.

The proclamation reads: "Whereas , welding a profession

requir ing cons iderable t ra ining and specialized study; further, the application of that training and specialized study is crit ical to the general well being for the count ry and calls for a constant stream of operators, design- ers, inspectors , engineers , teachers, and scientists from our schools and universities; and

W h e r e a s , the Sections and Dis- tricts of the American Welding Soci- ety wish to remind the public of the critical importance of welding; and

Whereas , the American Welding Society's District 8 encourages the participation in a public service program, Welding for Communities, that follows in the tradition of other profession's service for the common good; and

Now, Therefore , I, Don Sundquist , Governor of the state of Tennessee, do hereby proclaim April 23-29, 2000, as W e l d i n g Week in Tennessee, and encourage all citizens to recognize Welding for Communities

as the annual public service campaign of the American Welding Society." •

STANDARD N O T I C E S

AWS was approved as an accredited standards-preparing organization by the American National Standards Institute (ANSI) in 1979.AWS rules, as approved by ANSI, require that all standards be open to public review for comment during the approval process. This column also advises o f ANSI approval o f documents. The fol lowing standards are submit ted for public review.A copy may be obtained by sending the a m o u n t shown to AWS Technical Dept., 550 N. W. LeJeune Rd., Miami, FL 33126, or by calling (800) 334-9353.

Standards for Public Review

A3.0:200X, Standard Welding Terms and Definitions. Revised standard. $53.25. [ANSI Public Review expires 5/23/00.]

B5.16:200X,Specificationfor the Qual- ification o f Welding Engineers. New standard. $5.00. [ANSI Public Review expires 5/8/00.]

B5.17:200X, Specification for the Qual- ification o f Welding Fabricators. New standard. $4.75. [ANSI Public Review expires 6/6/00.]

D3.5-93R, Guide f o r Steel Hull Weld- ing. Reaffirmed standard. $29.50. [ANSI Public Review expires 6/6/00.]

D9.1:200X, Sheet Metal Welding Code. Revised Standard. $20.00. [ANSI Public Review expires 4/24/00.]

D l O. 7M/D l O. 7 : 2OO X, Recommended Practices f o r Gas Shielded Arc Weld- ing o f A l u m i n u m and A l u m i n u m Alloy Pipe. Revised standard. $12.50. [ANSI Public Review expires 6/6/00.]

D 17.1: 200X, Specification for Fusion Welding f o r Aerospace Applications. New standard. $32.50. [ANSI Public Re- view expires 5/23/00.]

ISO Standards for Public R e v i e w

ISO/DIS 5817, Welding - - Fusion- Welded Joints in Steel, Nickel, Tita- n i u m and Their Alloys (Beam Weld- ing Excluded) - - Quality Levels f o r Imperfections. Standard. $ 5.25. [ANSI Public Review expires May 31, 2000.]

ISO/DIS 9013, Thermal Cutting - - Classification o f Thermal Cuts - - Geometrical Product Specification and Quali ty Tolerances. Standard.

$6.75. [ANSI Public Review expires June 31,2000.]

ISO/DIS 17653, Destructive Tests on Welds in Metallic Materials - - Torsion Test o f Resistance Spot Welds. Standard. $2.00. [ANSI Public Review expires June 31, 2000.]

ISO/DIS 17654, Destructive Tests on Welds in Metallic Materials - - Inter- nal Pressure Test on Continuous Seam Welds. Standard. $1.75. [ANSI Public Re- view expires June 31, 2000.]

Revised Standards Approved by ANSI:

D10.6/D10.6M:200X, Recommended Practices f o r T i tanium Piping and Tubing, Gas Tungsten Arc Welding.Ap- proval Date: February 11,2000.

New Standards Approved by ANSI:

D8.14MD8.14:200X, Specification for Au tomot ive Components Weld Qual- ity A lu m in u m Arc Welding. Approval date: February 11, 2000.

R e a f f i r m e d S t a n d a r d s Approved by ANSI:

A5.6-84R, Specification fo r Covered Copper and Copper-Alloy Arc Welding Electrodes. Approval date: March 10, 2000.

D10.4-86R, Recommended Practices f o r Welding Austeni t ic Chromium- Nickel Stainless Steel Piping and Tub- ing.Approval date: March 10, 2000. •

62 I MAY2000

I N E W S

Boston Section Chairman Jim Reid, right, presenting the District Dalton E. Hamilton Memorial CWI of the Year Award to Derek Crowe.

D I S T R I C T I Director: Geoffrey H. Putnam

Phone: ( 8 0 2 ) 4 3 9 - 5 9 1 6

• GREEN & WHITE MOUNTAINS JANUARY 13 Speaker: Ray H e n d e r s o n , CWI and weld test administrator. Topic:The D1.1 Structural Welding Code. Activity: Henderson was assisted at the meet ing by District 1 Director Geoff Putnam, also a CWI.

FEBRUARY 10 Speaker: G e o f f P u t n a m , torch de- signer and AWS District One director. Affiliation: Therma l Dynamics, West Lebanon, N.H. Topic: Pulsed GTA welding. Activity: Hands-on demonstrat ions of pulsed GTA welding were given.

MARCH 10 Speaker: J o e Tokorsk i , welding inspector. Af f i l ia t ion: Bremco , Inc. , New- port , N.H. Topic: Boi le r codes and repa i r p rocedures .

Guest speaker Seann Bradle), during his presentation to the Long Is- land Section.

• BOSTON FEBRUARY 7 Speaker: P e t e r Ge ro , senior weld and process engineer. Affiliation: Pratt & Whitney. Topic: Laser and e l e c t r o n beam w e l d i n g of t u rb ine e n g i n e com- ponen t s - - p rocess cont ro l methods, jo in t des ign and meta l lu rg i - cal cons idera t ion . Activity: Sect ion Chairman J i m Reid presented the Dalton E. Hamil- ton Memorial CWI of the Year Award to D e r e k Crow.

• CENTRAL MASSACHUSETTS/ RHODE ISLAND MARCH 16 Speaker: R o b e r t W u n s c h e l , welding instructor. Affil iation: Greater New Bedford VocationalTech High School. Topic:The history and repairs of the S.S. Nobska, which was built in approximate ly 1920 at the Bath Iron Works near Portland, Maine.

D I S T R I C T 2 D i r e c t o r : A l f r e d F. F l e u r y

P h o n e : ( 7 3 2 ) 8 6 8 - 0 7 6 8

• LONG ISLAND MARCH 9 Speaker: S e a n n Bradley.

District 3 Director Claudia Kauf- man presenting the District Mem- bership Award to York-Central Penn- sylvania member Mike Bunnell.

Affiliation:The Lincoln Electric Co. Topic: Surface tension transfer welding.

• DELAWARE FEBRUARY Speaker: J i m G l a n c e y , professor, mechanical engineering. Affiliation: University of Delaware, Newark, Del. Topic:Weld design and application.

D I S T R I C T 3 D i r e c t o r : C l a u d i a B. K a u f m a n

P h o n e : ( 7 1 7 ) 3 9 7 - 1 3 1 2

• YORK-CENTRAL PENNSYLVANIA FEBRUARY 3 Speaker: Bil l C o r d i n g , market ing specialist. Affiliation:Air Products. Topic: Laser systems and their uses in various applications. Activity: District 3 Director Claudia Kaufman, left, p resen ted Margaret Malehorn wi th the District Direc- tor's Certificate Award for outstanding service wi th AWS. Kaufman awarded Mike Bunnell with the Dis- trict Membership Award.


D I S T R I C T 4 D i r e c t o r : R o y C. L a n i e r P h o n e : ( 9 1 9 ) 3 2 1 - 4 2 8 5

D I S T R I C T 5 D i r e c t o r : B o r i s A. B e r n s t e i n

P h o n e : ( 7 8 7 ) 8 8 3 - 8 3 8 3

• SOUTH CAROLINA FEBRUARY 17 Speaker: Ray T h o m a s , dis t r ic t manager. Affiliation: Miller Electric Mfg. Co. Topic:The use of mic roprocessors in welding equipment and their effect on weld bead p roper t i e s and the welding arc.

MARC8 16 Speaker: C h a r l i e A p p e l , regional sales representative. Affiliation: McGrady Sales. Topic: Manufacturing, appl ica t ion and selection of abrasives.

• SOUTH FLORIDA FEBRUARY 3 Speaker: D a v i d J . L a n d o n , corporate welding engineer. Affiliation:Vermeer Manufacturing. Topic: Vermeer 's we lde r training program and the company ' s product line.

D I S T R I C T 6 D i r e c t o r : G e r a l d R. C r a w m e r

P h o n e : ( 5 1 8 ) 3 8 5 - 0 5 7 0

• NIAGARA FRONTIER MARCH 2 Speu/eer.Frank Schweers, metal fabrication superintendent (retired) and instructor. Affiliation: QIS Welder Training Ser- vices, Buffalo, N.Y. Topic: Gas metal arc welding.

D I S T R I C T 7 Director : La r ry C. H e c k e n d o r n

Phone: (614) 4 5 7 - 2 6 4 0

• COLUMBUS FEBRUARY 10 Activity: The Sect ion toured the

Tour hosts Randy Magnolia, left center, and Todd Miller, right center, with Baton Rouge Section members during the Section's tour of the Volks Constructors facility.

Team Rahal facility in Hilliard, Ohio. Team Rahal has two sponsored cars - - Miller Lite and Shell - - that c o m p e t e in Champi- onship Auto R a c i n g Teams (CART) events. The mee t ing was a joint mee t ing wi th the Columbus Chapter of the Asso- ciat ion of Women in

the Metal Industries. Nashville Section members at their January The previous night, meeting. the Sect ion toured the facility for Student 's Night. Forty s tudents and advisors attended.

• MID-OHIO VALLEY FEBRUARY 15 Speaker: J o h n Abbit t , district manager. Affiliation:Thermal Dynamics. Activity:This was a joint mee t ing the West Virginia University-Park- ersburg.

• MEMPHIS JANUARY 6 Speaker: Cra ig H u m p h r e y s , sales representative. Affiliations: Hypertherm. Topic: Plasma arc cut t ing techniques.

• WHEELING MARCH 9 Speaker: T o m M y e r s , t e c h n i c a l sales representative. Affiliation: The Lincoln Electric Co., Pittsburgh, Pa. Topic: Plasma arc cutting.

D I S T R I C T 8 D i r e c t o r : H a r r e l l E. B e n n e t t

P h o n e : ( 4 2 3 ) 4 7 8 - 3 6 2 4

• NORTHEAST TENNESSEE FEBRUARY 22 Speaker:John DuPont . Affiliation: Lehigh University, Beth- lehem, Pa. Topic: Welding of stainless steel advanced double hull comba tan t ships. Activity: G e r r y S l a u g h t e r was awarded a 50-Year Cert i f icate for his long and dis t inguished service to the American Welding Society.

• NASHVILLE JANUARY 20 Activity: The Sect ion v iewed a video on the construction of the St. Louis Arch.

• NORTHEAST MISSISSIPPI FEBRUARY 24 Activity: The Sect ion toured the

64 I MAY 2000

Pascagoula Section Chairman Troy Gurkin, left, presenting a speaker's gift to Phil Pratt, left center, and Steve Brown, right, presenting one to Ron Scott.

New Orleans Section First Vice Chairman Damon Gerrets, left, present ing a speaker's award to Ray Broussard.

Raspet Flight Research Laboratory at Mississippi State University. J o h n T. B e r r y of the Mechanical Engineer ing Dept. arranged the tour.

D I S T R I C T 9 D i r e c t o r : O . J . T e m p l e t

P h o n e : ( 2 2 5 ) 3 4 3 - 4 8 0 6

• BATON ROUGE JANUARY 20 Speakers: R a n d y M a g n o l i a , manufactur ing manager, and T o d d Miller , vessel shop manager. Affi l iation:Volks Constructors, Inc. Topic: Pressure vessel shop operations. Activi ty:The Section toured the vessel and p ipe shops and wa t ched demons t ra t ions of a bevel head shape cutting machine.

• PASCAGOULA FEBRUARY 10 Speaker: P h i l Prat t , president, and Ron Scott, director of training Af f i l ia t ion: Hobart Inst i tute of Welding. Topic: Skill Career training and cer- tifications.

• NEW ORLEANS FEBRUARY 15 Speaker: Ray Broussa rd , owner. Affiliation:Maritime New Media, Inc. Topic: Multimedia and photo- graphic virtual reality as an industrial tool.

• MOBILE FEBRUARY 17 Speaker: O. J . T e m p l e t , distr ict 9 director. Affiliation: AWS. Topic: The future of the Amer ican Welding Society. Activi ty:Templet presented the Dis- trict Director's Certificate Award to J a c k i e Morr i s , L e o n J a c k s o n was honored with the District Howard E.Adkins Memorial Instructor Mem- bership Award and E l e a n o r Ezzel l r ece ived the District Meri tor ious Award. Area weld ing ins t ruc tors were invited guests of the Section for this meeting.

D I S T R I C T I 0 D i r e c t o r : V i c t o r Y. M a t t h e w s

P h o n e : ( 2 1 6 ) 3 8 3 - 2 6 3 8

D I S T R I C T I I D i r e c t o r : S c o t t C. C h a p p l e

P h o n e : ( 9 1 3 ) 2 4 1 - 7 2 4 2

• WESTERN MICHIGAN SEPTEMBER 27 Speaker:Jan C h r i s t i a n s o n . Aff i l iat ion :Flex-Cable. Topic: New direc t ions in the pre- ventative maintenance of resistance welding systems.

OCTOBER 25 Act iv i ty : The Sect ion toured the Dewis plant.

Leon Jackson, left, receiving an award f r o m District 9 Director o.J. Templet, right, while Section Chair- man Johnny Dediaux looks on.

DECEMBER 7 A c t i v i t i e s : T h e Section rece ived a tour of the Center Manufacturing plant.

JANUARY 24 Speaker: D o n a l d J e n k i n s , account manager for welding sales. Affil iation: FANUC Robotics. Topic: What's new in robotic welding and cutting.

FEBRUARY 28 Act iv i t ies : The Sect ion had a Stu- dent 's Night with student presentations and discussion of summer in- ternships . Named to the Sect ion 's Board were J i m Kos te r , chairman; S t a n l e y R u t k o w s k i III, secretary; and P h i l Schi f fer , treasurer.

• CENTRAL MICHIGAN FEBRUARY 15 Speakers: Paula Wi l son , associate, and J o d y Rouls , partner. Af f i l ia t ion: Michigan Automot ive Compressor, Inc. Topic:The Section toured the Michi- gan Automotive Compressor plant.


Central Michigan Section Chairman Russ Swanson, center, with Febru- ary meet ing hosts Jody Rauls, left, and Paula Wilson, right.

Milwaukee Section First Vice Chair- man Bob Schuster, left, with guest speaker Alan Belohlav, center, and Chairman Joe Campbell.

• NORTHERN MICHIGAN FEBRUARY 28 Activity: After its meeting, the Sec- t ion rece ived a tour of the Tower Automot ive plant. The tour was hosted by Ed Flees.At the meeting, member s were in t roduced to the regional winners of the Skills U.S.A./VICA welding compet i t ion . M i c h a e l K r u m m of Traverse City West High School won first p lace in GMA welding, and A d a m Wag- n e r of Kingsley High School won first place in GTA welding.

DISTRICT 12 D i r e c t o r : M i c h a e l D. K e r s e y

P h o n e : ( 2 6 2 ) 6 5 0 - 9 3 6 4

• MILWAUKEE FEBRUARY 17 Speaker: A l a n B e l o h l a v , brazing consultant. Affiliation: Lucas Milhaupt/Handy & Harmon. Topic: Why Braze? The six fundamentals of brazing.

Guest speaker Rich Hou,ard, left, ac- cepting a speaker's gift f r o m Louisville Section Chairman J im Gillespie.

St. Louis Section member Norm Hel- ton, left, presenting Jon Borkowski with a speaker's award.

• UPPER PENINSULA MARCH 14 Speaker: Bruce S te inborg . Affi l iat ion: Dickenson-Iron Inter- mediate Schools. Topic:Web sites and the Internet for AWS, and how the Internet functions.

DISTRICT 1 3 D i r e c t o r : J . L. H u n t e r

( 3 0 9 ) 8 8 8 - 8 9 5 6

• ILLINOIS VALLEY FEBRUARY 24 Speaker:Joe R. P iano . Affi l iat ion: Cycllops Welding and Manufacturing. Topic: Straits of Mackinac Bridge.

• CHICAGO MARCH 8 Speaker: Bob S c r i p n i c k , d i rec tor of machine tool sales. Affiliation: ESAB Cutting Systems, Florence, S.C. Topic: The his tory and scope of water jet cutting. Activity: In addition to the meeting, the Sect ion had a St. Patrick's Day dinner of corned beef and cabbage.

Lexington Section Chairman Frank McKinley, left, presenting an award to Billy Wilson.

DISTRICT 14 Director : Hil Bax

Phone : (314) 6 4 4 - 3 5 0 0 , ext. 1 0 5

• LOUISVILLE FEBRUARY 15 Speaker:Rich H o w a r d , manager of welding technology. Affiliation:Carrier Vibrating Equip- ment, Louisville, Ky. Topic: Defects and discontinuities.

• ST. LOUIS FEBRUARY 17 Speaker:John Borkowski . Afftliation:Tweco Robotic. Topic: Real-world requ i rements of robotic welding peripherals. Activity: The Sect ion toured the Pandjiris Inc. facilities.

• MISSISSIPPI VALLEY FEBRUARY 17 Activity: The Sect ion rece ived a guided tour of the ManchesterTank, Hannibal, Mo., facility from M a r c Hurt , shift 2 product ion manager.

68 I MAY 2000

Enjoying the Norhtwest Section's Annual Holiday Party are, f rom left, Chairman John Tousley and his wife, Mrs. Danielson and her husband Bruce and First Vice Chair- man Mike Hanson and his wife.

Attending the East Texas February meeting are, j rom left to right, Chairman Yoni Adonyg guest speaker Damian Koteckg Program Chairman Fred Klerekoper and District 17 Director Oren Reich.

Pictured are Northu,est Section scholarship recipients, fi 'om &ft to right, Eric Backeman, Jason Dannen, Richard Kooy (back), Brandon Bauer, Justin Kopp, Randy Mortland (back), Tyson Gerry, Kale Pribnow, Jeremiah Daniels and Timothy Harldson.

• LEXINGTON FEBRUARY 24 Act iv i t ies:The Section toured the Trane air-conditioning plant. Chair- man F r a n k M c K i n l e y presen ted the Section's Outstanding Educator Award to Bil ly Wi lson .

D I S T R I C T 1 5 D i r e c t o r : J . D. H e i k k i n e n

P h o n e : ( 2 1 8 ) 7 4 1 - 9 6 9 3

• NORTHWEST DECEMBER 9, 1999 Activi t ies:The Section held its An- nual Holiday Party. Bruce D a n i e l - s o n and R o b e r t O l s o n were awarded Lifetime Awards, and D o n Burke and Bill R e y n o l d s received the 25-Year Silver Award.

FEBRUARY 17 Activity:The Section held its Behind the Mask Welding Contest and Edu-

cat ion Scholarship Night.The Sec- t ion, along wi th six local companies, gave away $14,500 in scholarships for the year 2000/2001. Par- ticipating companies included Kurt Manufacturing ($500),Airgas North Central ($500 in supplies), Produc- tion Engineering Corp. ($1000), De- te rman Brownie Inc.($1000), Phillips & Termo Industries($1000) and Tennant ($1500).

• ARROWHEAD FEBRUARY 23 Speaker: J a c k Pezze, coordinator, apprenticeships. Aff i l iat ion: Steamfitters and Plumbers Local #11. Topic: Apprent iceships with the union - - educational requirements, training, pay and benefi ts and a course description.

D I S T R I C T 16 D i r e c t o r : C. F. B u r g

P h o n e : ( 5 1 5 ) 2 9 4 - 5 4 2 8

Sabine Section First Vice Chairman Morris Weeks, left, presenting a speaker's gift to Doug Landry

D I S T R I C T 1 7 D i r e c t o r : O r e n P. R e i c h P h o n e : ( 2 5 4 ) 8 6 7 - 2 2 0 3

• EAST TEXAS FEBRUARY 17 Speaker: D a m i a n Kotecki , technical director for stainless and high- alloy product development. Aff i l iat ion: The Lincoln Electric Co., Cleveland, Ohio. Topic:Weldability of duplex stainless steels. Activity: District 17 Director O r e n Reich attended the meeting.

D I S T R I C T 18 D i r e c t o r : J . M. A p p l e d o r n P h o n e : (281 ) 8 4 7 - 9 4 4 4

• SAN ANTONIO MARCH 9 Speaker: Bil l B r y a n t , safety consultant. Affiliation :Texas Workers' Compen- sation Commission. Topic: OSHA welder safety.


Puget Sound Section First Vice Chairman Ken L.Johnson, right, present ing Melvin Vice his second AWS scholarship check.

• SABINE MARCH 16 Speaker: Doug Landry , inspection manager. Af f i l ia t ion: Westlake Chemical, Lake Charles, La. Topic:The role of an inspector.

DISTRICT 19 D i r e c t o r : R. D. (R ich ) K e l l u m

Phone: ( 5 4 1 ) 9 2 4 - 0 1 8 8

• SPOKANE DECEMBER 15, 1999 Speaker: H o w a r d T h i e m e n s , QA manager. Affiliation: Spokane Industries. Topic:Alloying of steel.

• PUGET SOUND FEBRUARY 3 Speaker: L y n n A n n K a s k i n , first vice chairman, and E m e r y Rober ts , board of directors. Affil ia t ion : ASNT. Topic: Radiographic inspec t ion of welds, and the history of ASNT. Act iv i ty : M e l v i n Vice was presented with his second AWS scholarship check by FirstVice Chairman Ken L. Johnson.

March 2 Speaker: Steve M a d d e n , North- west sales manager. Af f i l ia t ion: Flow In te rna t iona l Corp., Kent, Wash. Topic:Waterjet: the machine tool of the future. Activity: The Puget Sound and Alaska AWS Sections have set up a new Alaska Welding Scholarship Fund to honor D o n H. Delk and David L. A n d e r s o n for their support of AWS,

Spokane Section members at their December meeHng.

Puget Sound Section First Vice Chair- man Ken L.Johnson, left, with guest speakers Steve Madden, center, and Chris Sundberg.

Inspectors and the Welding industry. Ken L. J o h n s o n and Chuc k Dai ly were thanked for contributing much of the proceeds from the Special Alaska Inspection Seminar 2000, which was held February 25 through March 1 .The next seminar will be presented May 5 through 10.

• PORTLAND MARCH 7 Speaker: Louis A. Novoa, chief engineer. Affil iation: Freightliner Corp. Topic:Alloying of steel.

DISTRICT 20 D i r e c t o r : N e i l R. K i r s c h

P h o n e : ( 9 7 0 ) 8 4 2 - 5 6 9 5

• COLORADO JANUARY 13 Speaker: J e r r y Jones, chief scientist. Aff i l ia t ion: Native American Tech- nologies Co., Golden, Colo. Topic: Welding data acquisi t ion, compute r moni to r ing e qu i pme n t and neural net systems.

District 22 Director Mark Bell during hispresentation to the San Fran- cisco Section.

FEBRUARY 10 Activity: Section members and their spouses and friends celebrated St. Valentine's Day/Ladies Night Out by attending a dinner theater performance of Fiddler on the Roof.

DISTRICT 21 D i r e c t o r : F. R. S c h n e i d e r P h o n e : ( 6 1 9 ) 6 9 3 - 1 6 5 7

• HAWAII MARCH 17 Speaker: J i m H o l l e n b e r g , secretary. Affiliation:AWS Hawaii Section. Topic:The 1999 District Conference in Waikiki.

DISTRICT 22 D i r e c t o r : M a r k B e l l

P h o n e : ( 2 0 9 ) 3 6 7 - 1 3 9 8

• SAN FRANCISCO MARCH 1 Speaker: Mark Bell, District 22 director. Affiliation:AWS. Topic:A commentary on welding.

7ol MAY 2000

• 1 9 9 9 - 2 0 0 0 M e m b e r - G e t - A - M e m b e r C a m p a i g n

The f o r m a t f o r r e c o g n i z i n g p a r t i c i p a n t s in the A WS M e m b e r - G e t - A - M e m b e r c a m p a i g n h a s c h a n g e d f r o m a "poin t s s y s t e m " to t h a t o f a s y s t e m w h e r e m e m b e r s a r e r e c o g n i z e d f o r the a c t u a l n u m b e r o f m e m b e r s they sponsor . C a m p a i g n ca tegor ie s a r e o u t l i n e d o n p a g e 65 o f th i s issue.

I f y o u h a v e a n y q u e s t i o n s r e g a r d i n g y o u r m e m b e r p r o p o s e r p o i n t s , p l e a s e ca l l the M e m b e r s h i p D e p a r t m e n t a t ( 8 0 0 ) 4 4 3 - 9 3 5 3 ext. 269 .

W i n n e r ' s C i r c l e ( I n d i v i d u a l s s p o n s o r i n g 2 0 o r m o r e n e w

m e m b e r s b e g i n n i n g J u n e 1, 1999 . )

J. D.Compton, San Fernando Va//ey - - 43 N. C.WalI, S o u t h F l o r i d a - - 42 E. H. E z e U , M o b i l e - - 29 B.A. Mikeska, H o u s t o n - - 24

President's G u i l d ( I n d i v i d u a l s s p o n s o r i n g 2 0 o r m o r e n e w

m e m b e r s b e t w e e n J u n e 1, 1999, a n d M a y

31, 2 0 0 0 . )

J. D. Compton, San Fernando Vaaey - - 43 N . C . W a U , S o u t h F l o r i d a - - 42 E. H. Eze l l , M o b i l e - - 29 B.A. Mikeska, H o u s t o n - - 24

President's Roundtable ( I n d i v i d u a l s s p o n s o r i n g 1 1 - 1 9 n e w

m e m b e r s b e t w e e n J u n e 1, 1999, a n d M a y

31, 2 0 0 0 . )

R.Wray, N e b r a s k a - - 19 W. L. Shreve, F o x V a l l e y - - 17

R. L. Peaslee, D e t r o i t B & S - - 16 G.W.Taylor, P a s c a g o u l a - - 11

President's C l u b ( Individuals sponsor ing 6 - 1 0 n e w m e m b e r s

be tween J u n e L 1999, a n d M a y 31, 2000.)

W . S t u r g e , N e w Y o r k - - 10 W . R. B e c k , R o c h e s t e r - - 10 R.J. D a v i s , N e w O r l e a n s - - 8

P. Baldwin, P e o r i a - - 8

R. Morgan, N o r t h w e s t O h i o - - 8

J.J. Daugherty, L o u i s v i l l e - - 7

EA. Juckem, M a d i s o n - B e l o i t - - 7

J.T. Merzthal, P e r u - - 7

R. Purvis, S a c r a m e n t o - - 7

E. S. Ruiz, P u e r t o R i c o - - 7

P. G. Childers, O k l a h o m a C i t y - - 6

R. L. Fidge, B a t o n R o u g e - - 6

J.Jones, N o r t h T e x a s - - 6

E. D. Levert, N o r t h T e x a s - - 6

J. H. Neal, E a s t e r n C a r o l i n a s - - 6

H.T.Timmerman, C e n t r a l T e x a s - - 6

S. O. Ufuah, N e w Y o r k - - 6

S. R. Zwilling, L o u i s v i l l e - - 6

President's H o n o r Roll ( Indiv iduals sponsor ing 1 -5 n e w m e m b e r s

b e t w e e n J u n e 1, 1999, a n d M a y 31, 2000.

Only those sponsor ing 2 o r m o r e A W S Reg-

u lar M e m b e r s are listed.)

K. M.AIi, S a u d i A r a b i a - - 5

R.J.Auciello, W o r c e s t e r - - 5

E E. Blake, S a g i n a w V a l l e y - - 5

C. L. Graves, D e l a w a r e - - 5

P. O'Leary, E a s t e r n I d a h o / M o n t a n a - - 5

J. G. Pierce, C o l u m b u s - - 5

J. Saucier, P a s c a g o u l a - - 5

M. R.Tryon, U t a h - - 5

EJ.Wernet, L e h i g h V a l l e y - - 5

G . W o o m e r , J o h n s t o w n - A l t o o n a - - 5

C. BurmlL Sotah PToni/a - - 4 D. Fairchild, H o u s t o n - - 4

H.Jackson, L o s A n ~ n l a n d E m p ~ - - 4 C. Laur id sen , H o r i d a S p a c e C o a s t - 4

R. L. Ledford,Jr., B i r m i n g h a m - - 4

H. R. M a d r o n , M a r y l a n d - - 4

W. L. Shreve, N o r t h w e s t O h i o - - 4

R. D. Zabel, S o u t h e a s t N e b r a s k a - - 4

B.A. Bernstein, P u e r t o R i c o - - 3

C.A. Castille, Jr., A c a d i a n a - - 3

A. L. Castro, P u e r t o R i c o - - 3 C.T. Corey, N o r t h e r n m. Y. - - 3

L DeFreitas, Santa Gain Vaaey - - 3 W. GalveryJr.,Long Bch/Orange Cnty - - 3 G. Gavela, L . A . / I n l a n d E m p i r e - - 3

R. Grays, K e r n - - 3

P. T. J a c q u e s , P o r t l a n d - 3

W. H. Kielhorn, E a s t T e x a s - - 3

J. Knapp, T u l s a - - 3

E. H. Ley, P i t t s b u r g h - - 3

G. E. Mayfield, T u l s a - - 3

W. P. Miller, Jr., N e w J e r s e y - - 3

J . W . M o r r i s , M o b i l e - - 3

S. L. Petty, P e o r i a - - 3

J. D. Sanders, H o u s t o n - - 3

R.J. S a m a n i c h , N e v a d a - - 3

C. E Schiner, W e s t e r n M i c h i g a n - - 3

A.T. Sheppard, C l e v e l a n d - - 3

G. Sinkule, N o r t h e r n M i c h i g a n - - 3

J. H . S m i t h , J r . , M o b i l e - - 3

J. K. Smith, T r i - R i v e r - - 3

B. H. Suckow, N o r t h e r n P l a i n s - - 3

M. Uddin, P a k i s t a n - - 3

R.Worden,Jr., W a s h i n g t o n , D . C . - 3

T. R.Alberts, S o u t h w e s t V i r g i n i a - - 2

J. N. Carney, W e s t e r n M i c h i g a n - - 2

J. C h a p a r r o , M e x i c o - - 2

B.A. Chin, B i r m i n g h a m - - 2

D.V. Day, C o r p u s C h r i s t i - - 2

J. M. DeDeaux, M o b i l e - - 2

H.W. Ebert, N e w J e r s e y - - 2

J.A. Grantham, C o l o r a d o - - 2

A. D. Grayson, N o r t h w e s t - - 2

D. L. Hatfield, T u l s a - - 2

J. P. Hennessy, F o x V a l l e y - - 2

D. L. Horsman, T u l s a - - 2

J.W.Jaeger, S o u t h e r n C o l o r a d o - - 2

K. E.Johnson, O l e a n - B r a d f o r d - - 2

R. S.Johnson, D e t r o i t - - 2

S. E.Johnson, C e n t r a l T e x a s - - 2

D. Klingman, C l e v e l a n d - - 2

O. C. Kooi, M a l a y s i a - - 2

J. Koster, W e s t e r n M i c h i g a n - - 2

S. K. C. Liu, C o l o r a d o - - 2

J.A. Livesay, N a s h v i l l e - - 2

H. V. M c R a e , N e w Y o r k - - 2

M.V. Medrano, S a n D i e g o - - 2

G. Menser , L o n g B c h . / O r a n g e C n t y . - 2

P. Mulville, S o u t h e r n C o l o r a d o - - 2

T.J. Murphy, C a n a d a - - 2

N. Nakwek, T h a i l a n d - - 2

D.A. Nance, I n d i a n a - - 2

T. L. Newman, T r i - R i v e r - - 2

E. E. Norman, O z a r k - - 2

J. Norris, S a n g a m o n V a l l e y - - 2

R. Norris, M a i n e - - 2

T. S. Nottingham, P u g e t S o u n d - - 2

D.W. Parker, I d a h o / M o n t a n a - - 2

J. L. Padilla, M e x i c o - - 2

J. Pelster, S o u t h e a s t N e b r a s k a - - 2 J. E. Pernell, L . A . / I n l a n d E m p i r e - - 2

M. D. Pitl~man, S h r e v e p o r t - - 2

M. R. Pointer, S i e r r a N e v a d a - - 2

G.A. Rubino, V e n e z u e l a - - 2

T. Searcy, S a n F e r n a n d o V a l l e y - - 2

O. G. Shair-Ali, S a n F r a n c i s c o - - 2

C . D. S m i t h , M o b i l e - - 2

A.W. Steven, M e m p h i s - - 2

M. D. Swigart, D a y t o n - - 2

M.Tait,LosAngeles/Inland E m p i r e - - 2

C.-L.Tsai, T a i w a n - - 2

D.J.Wohfeil, D e t r o i t - - 2

D.A.Wright, K a n s a s C i t y - - 2

Student Sponsors ( I n d i v i d u a l s s p o n s o r i n g 3 o r m o r e A W S

S t u d e n t M e m b e r s a r e l is ted.)

D. M. Boldt, P o r t l a n d - - 39 J. G. Owens, B a t o n R o u g e - - 24 D. Serrano, P u e r t o R i c o - - 21

M . R . A n d e r s o n , I n d i a n a - - 19 K. R. Geist, P u g e t S o u n d - - 18 P. G.Walker, O z a r k - - 18 P. Baldwin, P e o r i a - - 15 K.A. Ellis, M a r y l a n d - - 13

J.H. Smith,Jr.,Mobile- 13 W. P. Miller, Jr.,New Jersey - - 11 J.IL C o x , N o r t h e r n P l a i n s - 10 J. D. C o m p t o n , S a n F e r n a n d o Valley - - 7

W. S t m ~ , L o n g I s l a n d - - 7

S. P. Sivisld, M a i n e - - 6

R. Grays,Kern - - 5 R. L. Ledford,Jr.,Birmingham - - 5

S. G r e e n , N o r t h Texas - - 5

M.Tait, LosAngeles/Inland E m p i r e - - 4

& H ~ A n g e t e s / l n l a n d E m p i r e - - 3

WELDING JOURNAL 171

G U I D E T O A W S S E R V I C E S 5 5 0 N . W . L e J e u n e R d . , M i a m i , FL 3 3 1 2 6

P h o n e ( 8 0 0 ) 4 4 3 - 9 3 5 3 ; T e l e x 5 1 - 9 2 4 5 ; FAX ( 3 0 5 ) 4 4 3 - 7 5 5 9 I n t e r n e t : w w w . a w s . o r g

P h o n e e x t e n s i o n s a p p e a r i n p a r e n t h e s e s .

AWS P R E S I D E N T

Robert J.Teuscher, Manager, Welding Applications

Airgas 3574 Christy Ridge Rd.

Sedalia, CO 80135

ADMINISTRATION

Executive Director Frank G. DeLaurier, CAE (210)

Deputy Executive Directors Richard D. French (218) Jeffrey R. Hufsey (264)

John J. McLaughlin (235)

Assistant Executive Director Debbie A. Cadavid (222)

Director of Quality Systems Linda K. winiams (298)

Corporate Director of Finance/Comptroller Frank R.Tarafa (252)

INFORMATION SERVICES

Corporate Director Joe Cilli (258)

HUMAN RESOURCES

Director Luisa Hernandez (266)

INTERNATIONAL INSIII 'UTE OF WELDING

Information (294)

Provides liaison activities involving o ther professional societies and standards orga- nizations, nationally and internationally.

GOVERNMENT LIAISON SERVICES

Hugh K.Webster Webster, Chamberlain & Bean

washington, D.C. (202) 466-2976

FAX (202) 835-0243

Identifies sources of funding for welding educat ion and research & development . Monitors legislative and regulatory issues important to the industry.

WELDING EQUIPMENT MANUFACTURERS COMMI'I' |EE

Associate Executive Director Richard L.Alley (217)

INDUSTRY ACTION COMM[I~I'EE

Associate Executive Director Charles R. Fassinger (297)

COMMUNICATIONS

Corporate Director, Communications Nannette M. Zapata (308)

Corporate Director of Adminstrative Services Jim Lankford (214)

Corporate Director of Marketing Technical Services Division

Debrah C.Weir (279)

Promotes Society p rograms and activities to AWS m e m b e r s , the w e l d i n g c o m m u - nity and the general public.

CONVENTION & EXPOSITIONS Exhibiting Information (221, 256)

Managing Director Tom L. Davis (231)

Organizes the week-long annualAWS Inter- national Welding and Fabricating Exposi- t ion and Convent ion. Regulates space as- signments, registration materials and other Expo activities.

PUBLICATION SERVICES Division Information (348)

Managing Director JeffWeber (246)

WELDING JOURNAL

Publisher Jeff Weber (246)

Editor Andrew Cullison (249)

National Sales Director Rob Saltzstein (243)

WELDING HANDBOOK

Welding Handbook Editor Annette O'Brien (303)

Publishes AWS's month ly magazine, the Welding Journal, which provides information on the state of the welding industry, its technology and Society activities. Pub- lishes the Welding H a n d b o o k and books on general welding subjects.

MI~MBER/~ U ~,IOMISR ~EKVI~E3 Department Information (261)

Managing Director Cassie R. Burrell (253)

Assistant Director Rhenda A. Mayo (260)

Serves as a liaison between Section members and AWS headquarters. Informs members about AWS benefits and other activities of interest.

CERTIFICATION PROGRAMS/ BUSINESS DEVELOPMENT

Director Anna Petrosld (481)

Director of Int'l Business Development Walter Herrera

For customized certification and educational programs to industry and government.

EDUCATION

Director James R. Cunningham (219)

Information on education products, projects and programs. CWI, SCWI and other seminars designed for assistance in Certification. Re- sponsible for the S.E.N.S.E. beginning welder program and dissemination of education information on the Web.

CONFERENCES

Director Giselle I. Rodriguez (278)

Responsible for national and local conferences, seminars, individual corporate programs and home study courses on industry topics ranging from the basics to the leading edge of technology.

CERTtVICATION Information and application materials on cer- tifying welders, welding inspectors and edu- cators. (273)

Managing Director Wendy S. Reeve (215)

Awards & Fellows

Managing Director Wendy S. Reeve (215)

Coordinates awards and AWS Fellow nominees

TELEWELD

FAX: (305) 443-5951

For information about AWS technical publications, contact the Technical Services personnel listed below.

TECHNICAL SERVICES Department Information (340)

Managing Director William R. Oates (299)

Leonard P. Connor (302) Standards Activities Director, Qualification, Inspection, Food

Processing Equipment

Andrew R. Davis (466) International Standards Program Manager, Welding in Marine

Construction

Stephen P Hedrick (305) Safety and Health Manager, Symbols and Definitions

Engineers

Hardy H. Campbell III (300) Structural

Rakesh Gupta (301) Filler Metals

(a3ristopher B. PoUock (304) Brazing.Soldering Testing, Railroads, Computerization,

Insu-mnentation

Tim Potter (309) Robotics,Joining of Metals and Alloys, Piping and Tubing,

Friction Welding

Melvin O. Kulp (314) Oxyfuel Gas Welding & Cutting,Arc Welding and Cutting, Machinery

and Equipment,Welding Iron Castings

John L Gayier (472) Metric Practices, Sheet Metal, Plastics and Composites, Personnd Qualification

72 I MAY2000

ORDER DEPARTMENT (800) 334-9353 (305) 443-9353

Publication orders. Seminar and conference registrations.

Ed E Mitchell (254)Thermal Spray, High- Energy Beam Welding and Cutting, Re-

sistance Welding,Automotive,Aerospace

Senior Publ icat ions Coordinator

Rosalinda O'Neill (451)

AWS publishes more than 160 volumes of material, including standards that are used throughout the industry.

With regard to technical inquiries, oral opinions onAWS standards may be rendered. How- ever, such opinions represent only the personal opinions of the particular individuals giving them.These individuals do not speak on behalf of AWS, nor do these oral opinions constitute official or unofficial opinions or in- terpretations ofAWS. In addition, oral opinions are informal and should not be used as a substitute for an official interpretation.

It is the intent of the American Welding Society to build the Society to the highest quality standards possible. We welcome any suggestions you may have.

Please contact any of the staff listed on the previous page or AWS President Robert J. Teuscher, Airgas, 306 S. Chestnut, Colorado Springs, CO 80905.

AWS FOUNDATION, INC.

550 N.W. L e J e u n e Rd. Miami , FL 3 3 1 2 6 (305) 445 -6628

(800) 443-9353 , ext . 293 O r e-mail: b o b w @ a w s . o r g

C h a i r m a n , Board o f T r u s t e e s R o n a l d C. P i e rce

E x e c u t i v e D i r e c t o r Frank G. DeLaur ier , CAE

D i r e c t o r o f D e v e l o p m e n t R o b e r t B .Wi the re l l

T h e A W S F o u n d a t i o n is a n o t - f o r - p r o f i t c o r p o r a t i o n

e s t a b l i s h e d t o p r o v i d e s u p - p o r t f o r e d u c a t i o n a l a n d

s c i e n t i f i c e n d e a v o r s o f t h e A m e r i c a n W e l d i n g S o c i e t y .

I n f o r m a t i o n o n g i f t - g i v i n g p r o g r a m s is a v a i l a b l e

u p o n r e q u e s t .

• N o m i n e e s f o r N a t i o n a l O f f i c e Only Susta in ing Members , Members , Honora ry Members , Life M e m b e r s or Ret ired

M e m b e r s w h o have b e e n m e m b e r s for a per iod o f at least th ree years shall be eligible for elect ion as a Director or National Officer.

It is the duty of the National Nominat ing Commi t t ee to nomina te candidates for national office.The commit tee shall hold an open meeting, preferably at the Annual Meeting, at which members may appear to present and discuss the eligibility of all candidates.

To be considered a candidate for positions of President,Vice President,Treasurer or Di- rector-at-Large, the following qualifications and conditions apply:

P res iden t :To be el igible to ho ld t he off ice o f Pres iden t , an ind iv idua l m u s t have served as a Vice President for at least one year.

Vice President:To be eligible to hold the office o f Vice President , an individual m u s t have s e rved at least o n e year as a Director, o t h e r t h a n Execu t ive Di rec tor and Secre- tary.

Treasurer:To be eligible to hold the office o f Treasurer, an individual mus t be a me m - be r o f t he Society, o t h e r t h a n a S tuden t Member , m u s t be f r equen t l y available to t h e National Office and shou ld be o f execu t ive s ta tus in bus ine s s or indus t ry wi th experience in financial affairs.

Director-at-Large:To be eligible for e lect ion as a Director-at-Large, an individual shall previous ly have he ld office as Cha i rman of a Section; as Cha i rman orVice Cha i rman of a standing, technica l or special commi t t e e of the Society; or as District Director.

In te res ted par t ies are to s end a let ter s ta t ing w h i c h par t icular office t hey are seeking, including a s t a t emen t o f qualifications, their wi l l ingness and ability to serve if nom- inated and e lec ted and 20 copies of their biographical sketch.

This mater ia l s h o u l d be sen t to Shirley Bollinger, Cha i rman , Nat ional N o m i n a t i n g Commi t t ee ,Amer ican Welding Society, 550 N.W LeJeune Rd., Miami, FL 33126.

The nex t mee t i ng o f the National Nomina t ing Commi t t e e is current ly schedu led for Wednesday, April 26, 2000, in Chicago, Ill.The t e rms of office for candidates nomina ted at this meet ing will cot lmlence June 1,2001. •

• H o n o r a r y - M e r i t o r i o u s A w a r d s

The Honorary-Meritorious Awards Commit tee has the duty to make recommendat ions regarding nominees presented for Honorary Membership, National Meritorious Certificate, William Irrgang Memorial and the George E. Willis Awards.These awards are presented in conjunct ion with the AWS Exposition and Convention held each spring.The descriptions of these awards follow, and the submission deadline for consideration is July 1 prior to the year of presentation. All candidate material should be sent to the attention of John J. McLaughlin, Secretary, Honorary-Meritorious Awards Committee, 550 N.W. LeJeune Road, Miami, FL 33126.

N a t i o n a l M e r i t o r i o u s Cer t i f ica te Award : This award is g iven in r ecogn i t i on o f t he cand ida te ' s counse l , loyalty and devo t ion to t he affairs o f t he Society, a s s i s t ance in p r o m o t i n g cordial relat ions wi th indus t ry and o t h e r o rganiza t ions , and for t he con- t r i bu t ion o f t ime and effor t on b e h a l f o f the Society.

W i l l i a m I r r g a n g M e m o r i a l A w a r d : This award is adminis tered by theAmerican Weld- ing Society and sponsored by The Lincoln Electric Company to hono r the late William Irrgang. It is awarded each year to the individual w h o has done the mos t to e n h a n c e the Amer ican Welding Society's goal o f ad- vanc ing the s c i ence and t e c h n o l o g y of welding over the past five-year period.

George E. W i l l i s A w a r d : This award is a d m i n i s t e r e d by t h e A m e r i c a n W e l d i n g Soc ie ty a n d s p o n s o r e d by T h e L inco ln Elec t r ic C o m p a n y to h o n o r G e o r g e E. Willis. It is awa rded each year to an indi- v idua l for p r o m o t i n g t h e a d v a n c e m e n t o f w e l d i n g i n t e r n a t i o n a l l y by f o s t e r i n g c o o p e r a t i v e p a r t i c i p a t i o n in a reas s u c h as t e c h n o l o g y t ransfer , s t a n d a r d s rat iona l i za t i on a n d p r o m o t i o n o f i n d u s t r i a l goodwil l .

International Meritorious Certificate Award: This award is given in recogni t ion of the candidate 's significant cont r ibut ions to the wor ldwide we ld ing industry. This award shou ld ref lect "Service to the Inter- national Welding Communi ty" in the broad- es t t e r m s . T h e awardee is no t r equ i red to be a m e m b e r o f the Amer ican Welding So- ciety. Multiple awards can be given per year as the situation dictates.The award consists o f a cer t i f icate to be p r e s e n t e d at t h e award 's l u n c h e o n or at ano the r t ime as appropriate in conjunct ion wi th theAWS Pres- ident 's travel itinerary, and, if appropriate, a one-year m e m b e r s h i p to AWS.

Honorary M e m b e r s h i p Award: An H o n o r a r y M e m b e r sha l l be a p e r s o n o f a c k n o w l e d g e d e m i n e n c e in t he w e l d i n g profess ion , or w h o is acc red i t ed w i th ex- cep t iona l a c c o m p l i s h m e n t s in t he devel- o p m e n t o f t h e w e l d i n g art, u p o n w h o m the A m e r i c a n Weld ing Society sees fit to c o n f e r an h o n o r a r y d i s t i n c t i o n . A n Hon- o r a ry M e m b e r sha l l h a v e full r i g h t s o f m e m b e r s h i p . •


N e w L i t e r a t u r e For more information, circle number on

Catalog Features Industrial Coolers and Chillers

The company's complete line of water chillers and liquid coolers designed to control the temperature of coolants used in industrial applications such as machine tools, welding machines, lasers, molds, spindles, hy- draulics, processing equipment and EDM units are featured in this catalog. Included in the catalog are product information and specifications for the company's extensive lines of standard chiller and cooling systems. Examples of custom-built units to meet special cooling requirements are also presented. Systems are available for use as complete, closed-loop units on individual pieces of equipment or to cool a reser- voir of fluid supplying multiple systems.

Koolant Koolers 120 2625 Emerald Dr., Kalamazoo, MI 49001

i r~

ORBITAL WELDING Precision welding for process

tube and pipe industries • Fast set-up • With or without AVC • 100-600 amp power supplies • Open and closed chamber heads

M E S S E R Astro Arc Polysoude

1 - 8 0 0 - 2 2 1 - 1 9 1 7 email: [email protected] W133 N5138 Campbell Drive Menomonee Falls, Wl 53051


74 1 MAY 2000

Reader Information Card.

Brochure Features Automatic TCP Calibration System

A four-page, full-color brochure features the company's newly configured automatic tool center point (TCP) calibration system. The system ensures the robot always operates with a true, accu-

. . . . . . . . . ABI|

rate TCP without operator guesswork, and without the need to stop the robot and maneuver it over to a TCP calibration checkpoint. At regular intervals (e.g., every 10, 20 or even 100 parts), the robot can be programmed to zero in on the system,check its TCP and make all necessary adjustments. IftheTCP mis- alignment is less than 0.2 in., the system recalibrates and the robot goes back to work without operator interface. If the TCP is misaligned more than 0.2 in., the operator can either manually align the welding gun using the calibration check pointer or let the system do the recali- bration. Any deviation is automatically

time stamped and recorded in the system's software program to assist service personnel when performing maintenance. The system also assures proper wire electrode extension length, adjusts for contact tip wear or changes in wire cast and calculates the TCP to the center of the wire's diameter. In addition, it can verify the robot arm is accurately calibrated and, upon command, update the gun angle.

ABB Flexible Automation Inc. 121 4600 Innovation Dr., Fort Collins, CO 80525

Brochure Highlights Jib Workstation Crane

This workstation jib crane brochure highlights detailed information on the

company's new forkliftable counter- weight bases and its freestanding and wall cantilever enclosed track frames.


The portable bases do not require pour- ing foundations or anchoring bolts to the floor and are ideal when a crane must be used in several different locations in the workplace. The enclosed track systems allow easy ergonomic movement and up to 360-deg rotation.

Spanco, Inc. Morgantown Business Park, Hemlock Road Morgantown, PA 19543

122

Safety Products Catalog Released

This 300-page, full-color safety product catalog features popular safety products for all industries and applications, including protective and disposable clothing, boots, protective eyewear,

THE ROAD TO TECHNOLOGY

l ! hearing protection products, first aid supplies, respiratory protection products, ergonomic products, head/face protection products, Iockout/tagout equipment, fall protection products and thousands of styles of glo~'es. In addition to the vast assortment of products manufactured by the company, the catalog includes more than 200 other leading brands.

Magid Glove and Safety Mfg. Co. LLC 123 2060 N. Kolmar Ave., Chicago, IL 60639-3483

Blue Book of Sheet Metal and HVAC Equipment Published

The second edition of the Blue Book of Sheet Metal and HVAC Equipment, a 62-page reference book, is a cost guide for tools and shop equipment that can resolve disputes about equipment charges. It provides use rates for tools and equipment found in the shop or job site. Rates in the guide reflect the actual costs incurred by contractors and include allowances for such items as de-

preciation, equipment-related overhead, cost of facilities capital, repair and maintenance costs and more. The guide makes it easy for engineers and archi- tects to determine costs for time and material fees on jobs. Nonmembers of SMACNA may purchase Blue Book of Sheet Metal and HVAC Equipment for $6O.

Sheet Metal and Air Conditioning Contractors' National Assoc. Inc. 4201 Lafayette Center Dr., Chantilly, VA 20151

Corrosion Catalog Features Books, Software and Related Products

This product guide features more than 1000 books, technical standards, software and related products for corrosion control and prevention efforts in industries including plant maintenance; aerospace and automotive; electronics and military; chemical processing; protective coatings and linings; engineering, construction and design; metal-

T a k e , t h e r o a d to t e c h n o l o g y w i t h J e t l l n e ' s 9 5 0 0 ~ C o n t r o l l e r

We pu t the h i ghes t t e c h n o l o g y i n t o ou r p r o d u c t s so t ha t you d o n ' t have to w o r r y a b o u t you r w e l d i n g process. Our t e c h n o l o g y p r o v i d e s you w i t h the very best p e r f o r m a n c e

you shou ld e x p e c t f rom you r w e l d i n g sys tem.

Je t l i ne ' s u m q u e 9500 System Con t ro l l e r b r i n g s t e c h n o l o g y to you r a p p l i c a t i o n . Just l ook at i ts fea tu res :

Cont ro ls f o u r w e l d i n g p a r a m e t e r s - s i m u l t a n e o u s l y : Su i t ab le fo r a l l a rc w e l d i n g processes.

Uses c losed loop con t ro l for the u l t i m a t e i n a c c u r a c y . S ing le or m u l t i - p a s s w e l d c o n t r o l . :

Con tac t J e t l i n e - le t the c o m p a n y w i t h the h i g h e s t ~ t e c h n o l o g y i n hard a u t o m a t i o n b r i n g t h e i r k n o w l e d g e and t e c h n i c a l e x p e r t i s e to bea r to solve y o u r w e l d i n g

r L - ) 1 5 GOODYEAR S T R E E T , I R V I N E , F~,A 9

q.g) g

COM "

Circle No, 20 on Reader Info-Card WELDING JOURNAL I 75

lurgy; oil and gas, petroleum production and refining; pipeline and underground systems; power and utilities; pulp and paper; transportation; water and wastewater; and marine and offshore. More than 50 new corrosion reference books, technical standards and software programs are highlighted.

NACE International, The Corrosion Society P.O. Box 218340, Houston, TX 77218-8340

124

Catalog Highlights Company's Welding Technology

The company's full line of patented technology and products, including the newest welding and plasma arc cutting products, are featured in this 84-page, full-color catalog. Case study sections are included to demonstrate how customers in different applications utilize the company's products and technologies. The catalog also has a guide for

Introducing the Speedglas ® Fresh-air ~ II 9000 Powered Air-Purifying Respirators:

The finest auto-darkening welding lens in the world; choose from 4 different Speedglas ® 9000 lenses.

2. An ultra-modern helmet design: narrower width, extended throat protection, heat-reflecting silver front,

and super lightweight corn fort.

3. The exclusive ,peedglas SideWindows" ~tion for peripheral vision =t increases the welder 's field iew by 100%.

~ere's the battery? Now it right into the turbo unit,

,,,c1~.,,,~5 u,e system more compact.

l S p e e d g l o s m

H O R N E L L S P E E D G L A S I N C .

2374 Edison Blvd. • Twinsburg, Ohio 44087 USA • Tel: 800-628-9218 or 330-425-8880 Fax: 330-425-4576 • in [email protected] • www.speedg las .com

©1998 Home, $peedglas Inc gpeedglas®, Fresh-air® and SideWindows TM are trademarks of Hornell gpeedglas Inc Proprietary designs protected by patents worldwide

Cir©le No, 18 on Reader la fo-Card

Speedgias Fresh air II G 9000 System for f i l tra- t ion of specif ic gases, vapors & particulates.

76 I MAY 2000

choosing the best welding or cutting product for a desired application, including information on advantages and

disadvantages of various welding and cutting processes. Full-color photos and suggested accessories accompany each product description, and color-coded symbols help identify process capabilities and power specifications for each product.

Miller Electric Mfg. Co 125 1635 W. Spencer St., Appleton, WI 54912

Catalog Highlights Abrasives

The 40-page Quality Coated Abra- sives catalog describes the company's entire line of stocked, coated abrasive belts, rolls, discs and sheets; nonwoven

fiber abrasives; and specialty products and accessories including pump drum sleeves, sanding sponges, discs and disc holders and disc backup pads. A chart shows all grit sizes available on stocked products for silicon carbide, aluminum oxide and zirconia alumina products and fiber discs. The chart also provides information on each product's backing and advantages. Also included is a comprehensive application guide for metalworking, woodworking, glass, rubber, stone, brick and ceramics.

VSM Abrasives Corp. 1012 E. Wabash St., O'Fallon, MO 63366

126

Braz ing Q & A

Q: Will BNi-5 brazing filler metal remelt on a second run if taken back up to heat after being brazed at 2150°F (1177°C) for 10 min? Our shop personnel claim that it will not. Could you shed some light on this?

A: As found in all brazing, to obtain certain properties, there are many variables to take into consideration when processing a part. BNi-5 is a nickel-based filler metal with a nominal 19% Cr and 10.2% Si. The filler metal has a solidus of 1975°F (1080°C) and a liquidus of 2075°F (1135°C). Again, the solidus and liquidus are nominal temperatures found in the nonmandatory part of the specification as a reference. The reason for this is that the chemistry of the filler metal is controlled by specification, and, due to the complexity of manufacturing and chemical analysis, there is always a range for each element. In manufacture, the actual chemistry of

each element can vary within its specific range, thus changing the liquidus temperature and, with some filler metals, also the solidus temperature.

Silicon is the melting-point depres- sant in the BNi-5 filler metal, which makes the nickel-chromium alloy melt at a low enough temperature to be a suitable brazing filler metal. To increase the remelt temperature, the silicon must either be diffused out of the brazed joint to change its melting temperature or other elements diffused into the joint area, again changing the melting temperature, or a combination of both, which is what generally occurs.

One factor that affects the rate of diffusion is the atomic diameter of the element. For example, silicon has an atomic diameter of 2.65 A. The atomic diameter of boron is 1.80 A, which is approximately half the size of the silicon atom. Therefore, the silicon atom has much less mobility during the dif-

BY ROBERT L. PEASLEE

fusion cycle of brazing than would an atom of boron. For further comparison, carbon is listed as 1.54 &. When the base metals are examined, it is found the atomic diameter of nickel is 2.49 A, iron is 2.52 & and chromium is 2.57 g,. Boron as a melting-point de- pressant has much more mobility during diffusion than does the much larger silicon atom. Since silicon is still larger than the nickel, iron or chromium, its ability to move during diffusion is much less.

The rate of diffusion of the elements rapidly increases with increasing temperature. Silicon being such a large molecule, the increase in temperature speeds up the rate of diffusion, but it is not very effective, even at 2150°F.

In looking at the increasing time at the brazing temperature vs. diffusion, increasing time does increase the diffusion that takes place. However, the

- - c o n t i n u e d o n p a g e 7 9

Advanced Alloy Products COLMONO Y® Alloys Since 1938, Colmonoy wear-resistant surfacing alloys have been extending the service life of machine components . Our nickel-based alloys will lower your repair and replacement costs and increase your productivity. We customize our alloys to meet your application needs. Colmonoy alloys are available in powder , rod and wire.

Colmonqy thermal spray systems.

N I C R O B R A Z ® Filler Metals These are the original ~:,v .............. <~ and best known nickel- based brazing filler metals. A variety of composit ions are available to meet industry specifications, including AMS, AWS, and G.E. Our Nicrobraz pr(×tucLs are avai lable in powder , paste, rod and tape.

Nicrobr~lz pvodltcl.~.fro/*l att/otnotit'e to oevospace.

F o r i n f o r m a t i o n o n C o h n o n o y o r N i c r o b r a z . c i r c l e t h e r e a d e r c a r d n u m b e r o r c a l l 2 4 8 - 5 8 5 - 6 - t 0 0

THE WALL COLMONOY CORPORATION 30261 Stephenson Highway • Madison Heights, MI 48071-1650 * Tel: 248-585-6400 ° Fax: 248-585-7960

w w w . w a l l c o l m o n o y . c o m ° ISO 9001, AS-9000 and NADCAP Accredi ted

C i r c l e No. 3 7 on R e a d e r I n f o - C a r d WELDING JOURNAL I 77

S t a i n l e s s O & A

BY D A M I A N J. KOTECKI

Q: In the August 1999 issue, you explained why mild steel is not an appropriate filler metal for joining mild steel to 304 stainless. Still thinking along the lines of choosing a filler metal to "match the weakest link," why should I choose an overal loyed fi l ler metal such as ER309LSi instead of just matching the 304 stainless with ER308LSi?

A= Since a lower alloyed fi l ler metal would be less expensive than ER309LSi, it is indeed tempting to make the weld using a fi l ler metal that nearly matches the 304 side, such as ER308LSi for GMAW. However, this is also a risky proposition. To understand this, it is helpful to plot the situation on the WRC-1992 Diagram, which is modified by the recent addition of a martensite boundary.

To begin the analysis, typical compositions for a C1018 mild steel, a 304 stainless steel and an ER308LSi welding wire for GMAW are given in Table 1. First, considering just the two base metals, you can usually assume approximately equal contribution to weld metal dilution from each side of the joint. So, plot the C1018 and 304 compositions on the diagram and draw a tie-line between these two points. The "Rule of Mix ing" says all possible mixtures of these two base metals must lie along this tie-line. Then, if each base metal con- tributes an equal amount to the dilution, you can imagine a "synthetic base metal" as the midpoint of this tie-line, which is shown on the modified WRC-

~" 18 o ~ 16

~ 14

~ t 2 o N ÷ 10

÷ 6 Z

. 4

.._" " 2 D" LU

• 0

0 2 4 6 8 10 12 14 16 18 20 22 Cr Equiv. = %Cr + %Mo + 0.7(%Nb)

24 26 28 30

Fig. 1 - - WRC-1992 Diagram analysis of joining 304 stainless to mi ld steel using ER308LSi filler metal.

1992 Diagram in Fig. 1. Next, plot the ER308LSi composition

on the diagram and draw a tie-line between this point and the "synthetic base metal." The Rule of Mixing says all possible mixtures of the ER308LSi f i l ler metal with equal amounts of the two base metals wi l l lie along this second tie-line. In GMAW, dilution is normally between 30 and 40%, so the resulting weld metal wi l l lie somewhere between 30 and 40% of the distance from the ER308LSi f i l ler metal to the mixture of the two base metals. In Fig. 1, the expected weld metal is shown at 30% and at 40% of the distance from the ER308LSi f i l ler metal to the equal mixture of the two base metals.

From this analysis, it can be seen the points corresponding to the expected weld compositions in Fig. 1 would be just about on the extension of the zero Ferrite Number (0 FN) line. With no ferrite, the weld would be expected to be sensitive to hot cracking. While not all such welds wi l l crack, some very likely wi l l . Further, the weld at 40% di lut ion is dangerously close to the martensite boundary. A little higher di lut ion and the weld could contain martensite and be brittle. These are usually unaccept- able risks, so it is generally not recommended to use ER308LSi filler metal for this joint.

ER309LSi fi l ler metal is more highly alloyed than ER308LSi and its Ferrite

Table I - - Compositions for ER3OSLSi to Join C1018 to 304

%C %Cr % Ni %Mo %Cu

C1018 0.18 0.02 0.03 0.01 0.07 304 0.05 18.30 8.80 0.05 0.08 Equal Mixture of 0.12 9.16 4.42 0.03 0.08 304 and C1018 ER308LSi 0.03 19.90 10.20 0.21 0.19 Weld, 30% Dilution 0.056 16.68 8.46 0.16 0.16 40% Dilution 0.064 15.60 7.89 0.14 0.14

% N Creq Ni~ FN

0.01 0.03 6.59 - - 0.04 18.35 11.37 4 0.03 9.19 8.98 - -

0.06 20.12 12.50 7.5

0.050 16.84 11.44 0.5 0.046 15.75 11.09 0

Table 2 - - Compositions for ER309LSi to Join C1018 to 304

%C %Cr %Ni

ER309LSi 0.02 24.10 12.70 Weld, 30% Dilution 0.049 19.62 10.22 40% Dilution 0.058 18.12 9.39

% Mo % Cu % N Cr~ Ni~ FN

0.13 0.16 0.05 24.24 14.44 18

0.10 0.13 0.043 19.72 12.80 5 0.13 0.13 0.040 18.22 12.26 2

7 8 1 MAY 2000

Number tends to be considerably higher. Table 2 lists a typical ER309LSi composition, and, with the same two base metals as Table 1, Table 2 also lists the calculated weld metal at 30% dilution and at 40% dilution. This time, the weld is calculated to contain from 5 FN at 30% dilution to 2 FN at 40% dilution. Such compositions would be highly resistant to hot cracking. A plot of the situation, developed using the analysis similar to that of Fig. 1, is given in Fig. 2.

It can be seen from Fig. 2 that, with minor variations in the dilution obtained with the ER309LSi filler metal, the weld will not produce compositions without ferrite. Also, the calculated weld composition is well above and to the right of the martensite boundary, indicating the weld will be ductile, even with small variations in dilution. So this is a much safer choice than the ER308LSi filler metal.

The above analysis also holds true for SMAW and FCAW with slight composition modifications because the filler metal composition requirements are not quite the same. This explains why 309L, in one form or another, is usually recommended for joining mild steel to 304 stainless. However, the analysis may not

~ ' 1 8 U

o ÷ 14

o

÷ 10

~ 8

.*_ s z

I |

._~ g

4

2

0

0 2 4 6 8 10 12 14 t6 18 20 22

Cr Equiv. = %Cr + %Mo + 0.7(%Nb)

24 26 28 30

Fig. 2 -- WRC-1992 Diagram analysis of joining 304 stainless to mild steel using ER309LSi filler metal.

hold true with SAW because of the much higher dilutions possible with SAW. While 30 to 40% dilution is possible at low submerged arc welding currents for a given wire size, dilution of 60% or more is also possible using higher submerged arc current. Then, even an ER309L or ER309LSi filler metal may not be a safe choice. A safer choice for SAW would be a filler metal still more highly alloyed than 309, such as ER309LMo or ER312.~

DAMIAN J. KOTECKI is Technical Director for Stainless and H igh -A l l oy Product Development for The Lincoln Electric Co., Cleveland, Ohio. He is a member of the AWS ASD Subcommittee on Stainless Steel Filler Metals; AWS D1 Structural Welding Committee, Subcommittee on Stainless Steel Welding; and a member and past chair of the Weld ing Research Counc i l Subcommittee on Welding Stainless Steels and Nickel Base Alloys. Questions may be sent to Mr. Kotecki c/o Welding Journal, 550 N.W. LeJeune Rd., Miami, FL 33126.

-- continued from page 77

time must be excessively long to diffuse a large amount of silicon out of the brazed joint because the silicon atom is so large.

A major variable is the quantity of filler metal in the joint vs. diffusion. As the clearance of the joint increases, the amount of silicon in the joint filler metal increases, thus taking a much longer time, a higher temperature or both to reduce the silicon in the joint to a low enough concen- tration to increase the remelt temperature of the joint.

Another variable is the type of base metal used. Different base metals al low a certain element to diffuse faster or slower than other base metals. The type of base metal must be taken into consideration when looking at diffusion brazing characteristics.

As can be seen, the processing variables have a large effect on the remelt temperature of a diffusion brazed joint. BNi-5, when used to braze 304 stainless at 2150°F for 10 min at heat, with a joint clearance of

0.003 in., would certainly remelt when taken up to a similar brazing cycle. A joint made in Al loy 600 (N06600) brazed at 2150°F for 30 min with a 0.001-in. clearance would not be expected to remelt on a similar cycle.

One occurrence that causes con- fusion is the fact large fillets do not sufficiently diffuse to prevent remelt- ing. The braze joint may be completely solid with a high remelt temperature, but the fillets will still melt and flow; therefore, many consider the braze joint remelted, which it is not. In this case, the melting of the fillet from the remelt of the braze joint itself must be considered separately.

A good method for testing diffusion brazing is to use a V-type specimen. This can be made from two pieces of the base metal to be used that are 0.25 in. thick x 0.500 in. wide and 4 in. long. The two wide surfaces are placed side by side and tack welded with 0.000 in. clearance at one end and 0.005 in. at the other end. With the specimen horizontal and the joint vertical, the filler metal is placed on top of the joint and then brazed. The specimen is then cut at a right angle to the joint, exposing the full length of the V-joint. After pol-

ishing and etching with Marbles Reagent, the structure of the brazed joint can be seen at 200X magnification at the 0.005 in. clearance end. Generally, no etched detail in the filler metal will be seen at the 0.000 in. clearance end. Looking along the specimen, there wil l be a clearance where a secondary phase will begin. The secondary center phase is the lower melting fil ler metal that wil l remelt. It is desirable to change the time at heat, increase the brazing temperature or reduce the clearance in the production parts when they have a larger clearance than where the secondary center phase starts.

Several reasons the boron-containing fil ler metals have found a large part of the market is they are lower melting than the silicon alloys and have the abil ity to more rapidly diffuse the boron out of the joint, thus producing high remelt temperatures with improved physical properties.#

R. L. PEASLEE is Vice President, Wal l Colmonoy Corp., Madison Heights, Mich. This article is based on a column prepared for the AWS Detroi t Brazing and Soldering Division's newsletter. Reader questions may be sent to Mr. Peaslee c/o Welding Journal, 550 N.W. LeJeune Rd., Miami, FL 33126.


Navy Joining Center

Operated by

Knowledge-Based Ultrasonic Inspection System Development Near Completion

T he objective of this Navy Joining Center (NJC) MANTECH project is to develop, test and commercial-

ize a knowledge-based ultrasonic inspection system (KBIS) for steel welds. This is a significant advance in ultrasonic inspection technology. Instead of relying on only ultrasonic amplitude, discontinuity length and proximity measurements to accept or reject a discontinuity, KBIS will determine both the type and through-thickness height of the discontinuity. The use of KBIS will lower weld reject rates and associated repair costs by providing justification to accept limited amounts of discontinuities, which, without classification and sizing capabilities, would be rejected by current manual ultrasonic inspection methods. The benefit to the U.S. Navy will be reduced life-cycle costs of ownership for submarines and surface ships.

System Features The prototype KBIS consists of a com-

puter-based ABB Amdata IntraSpect- UX2 ultrasonic inspection system up- graded to perform discontinuity classification, sizing and reporting functions. A neural network trained to identify different types of flaws in steel welds ac- complishes discontinuity classification. After the discontinuity has been classified, the menu-driven system will allow an inspector to size the flaw. The sizing procedures, developed specifically for Navy submarine hull applications, are manual scanning methods based on well-understood tip diffraction and dB- drop methods. The system's imaging capability is used as an aid to identify the tip diffracted signals. After completing the classification and sizing operations, KBIS maintains a record of the respec- tive A, B and C ultrasonic scans, wave- forms, classifier results, final discontinuity disposition and inspector's com- ments. These and other output data can be provided in both hard copy and electronic formats for future discontinuity monitoring, independent review and audit.

The Neural Network Classifier

A key element of the KBIS system is the neural network classifier, which was developed for this project by Iowa State University. An A-scan database was collected, organized into training and validation sets and used to build the feature classification algorithms of the neural network. A-scan data was collected for more than 70 cracks, incomplete fusion, slag and porosity discontinuities located in different regions of welds. These discontinuities were selected from a set of well-documented ultrasonic and radiographic inspection test plates provided by the Naval Surface Warfare Center, Carderock Division.

The neural network was initially developed to classify discontinuities as being either planar or volumetric. As work progressed, it became evident the planar indications could be categorized as either cracks or incomplete fusion, and the volumetric indications could be categorized as either porosity or slag. Invariance testing was performed as part of the neural network development effort to ensure proper performance over a wide range of conditions. This testing evaluated classifier performance using a variety of commercially available ultrasonic transducer brands and types, transducer angles and frequencies and inspection directions.

System Validation A team from the Edison Welding In-

stitute; the Navy Surface Warfare Cen- ter, Carderock Division; and Kok and Associates is conducting an extensive series of validation tests on KBIS. This validation effort is testing the performance of the system's hardware and software, classifier and sizing procedure. Classifier and sizing procedure performance testing is being accomplished by inspecting several sets of specially prepared welded test plates as well as qualification samples from participating shipyards and the Electric Research Power Institute. The specially prepared

test plates were fabricated for this project so the actual size and character of the discontinuities can be determined by sectioning, then comparing them to KBIS predictions.

Inspectors from Puget Sound Naval Shipyard and from General Dynamics, Electric Boat Corp., will perform redun- dant field tests of the KBIS as part of system validation. Final demonstrations of the system also will be conducted at Navy and commercial shipyards where actual discontinuities will be evaluated.

Summary The KBIS, which is presently in the

final stages of validation testing, will improve an inspector's ability to analyze ultrasonic weld inspection data and assess discontinuities compared to the normal methods that evaluate signal amplitude, discontinuity length and the proximity between discontinuities. Ini- tial results clearly demonstrate the ability of a neural network to classify crack, incomplete fusion, slag and porosity discontinuities. When fully validated, KBIS will become commercially available for use by shipbuilders to classify and document weld discontinuity type and size during manufacturing, overhaul and repair of steel ship and submarine structures. With proper validation, KBIS also can be applied to the inspection of critical welds in chemical and power generation equipment, buildings, bridges and heavy machinery.

For further information about KBIS, contact Tim Trapp, projects manager, NJC, at (614) 688-5231, e-mail tim_trapp@ ewi.org, or Roger Spencer, project engineer, N DE Group- EWl, at 614-688-5216, e-mail [email protected].

n J c Operated by

E U / i

The Navy Joining Center 1250 Arthur E. Adams Dr. Columbus, OH 43221 Phone: (614) 688-5010 FAX: (614) 688-5001 e-mail: [email protected] www: http:llwww.ewi.org Contact: Harvey Castner

80 [ MAY 2000

P e r s o n n e l

DCT Names Vice President

DCT, Sterling heights, Mich., announced the appointment of John Baysore lAWS] as vice president and

Baysore

general manager of the newly created NO-WAT® Technologies business unit. His responsibilities include developing the market for new welding technology and growing the business unit. Baysore had served as vice president of the company's Utilase Blank Welding Technologies business unit throughout the mid-1990s until its sale in 1997 to Noble International, Bloom- field Hills, Mich. He stayed on as president of the company until rejoining DCT this year. He holds a bachelor of science degree in welding engineering from The Ohio State University and has done extensive graduate studies in electrical engineering.

Ebert Announces Retirement

Harry W. Ebert lAWS], an AWS Life Member and past director-at-large, announced his retirement from ExxonMo- bil Research and Engineering, Florham Park, N.J., after 34 years with the company. Ebert, who joined the com~hpany in 1966 as principal welding engineer, served as an engineering associate in the Materials Section. His responsibilities spanned a wide range including R&D, training, new construction, maintenance and trouble-shooting with applications on pressure vessels, piping systems and furnaces, as well as min- ing equipment and supertankers. After World War II interrupted his education, Ebert returned to The Ohio State Uni- versity and became a member of the first class to be awarded a bachelor's degree in welding engineering from the university. He earned his M.S. at

Newark College of Engineering. He has authored all 52 editions of the applied guide For Welders Only. Ebert was elected an AWS Fellow in 1995 and received several awards from the Society. He is active in and has, at times, chaired the AWS Filler Metal, Piping and Hand- book Committees. He has taught engineering subjects at several colleges and is a retired U.S. Army Colonel.

Obituaries

Glenn J. Gibson

Glenn J. Gibson lAWS], an AWS Life Member, New Jersey Section member and the initial benefactor of the AWS

Gibson

Foundation, died on March 25. His gen- erous pledge marked the beginning of the Foundation and was an encourage- ment to others to contribute.

Gibson earned a degree in civil engineering from Lehigh University, Beth- lehem, Pa., in 1935. He received a fel- lowship sponsored by the AWS Struc- tural Steel Welding Committee at the university's Fritz Laboratory. After two years of structural welding research and some advanced physical metallurgy courses, he received his master's degree in civil engineering from Lehigh. After graduating he settled in the Pitts- burgh, Pa., area and pursued a career in tank welding and shipbuilding. After World War II, he joined Airco to work in research and development at its laboratory in Murray Hill, N.J. While at Airco in 1950, Gibson co-invented the gas metal arc welding process. The Muller, Gibson and Anderson patent 2,504,688 is considered by most experts as the basic gas metal arc welding (GMAW) patent.

Gibson left Airco in 1962 to found

Gibson Tube, Inc. His son, Jim, became president of the company upon his retirement in 1982.

Harry F. Reid, Jr.

Harry F. Reid, Jr. lAWS], a 52-year member of AWS and a member of the 1999 AWS Class of Fellows, died on Saturday, March 18, at York Hospital in York, Pa.

Reid graduated with a degree in chemistry from Geneva College, Beaver Falls, Pa., in 1939. In 1948, he received his master's degree in chemical engineering from The Ohio State University. He worked briefly as a plant chemist in Pittsburgh, Pa., before jo in ing Battelle Memorial Insti- tute, Columbus, Ohio, in 1942 as a research engineer. Whi le there, he was a contr ibutor to the Manhattan Project. Reid left Battelle in 1952 to join McKay Co., York, Pa., where he was technical service manager, first in the Welding Products Div. and later in the Chain and Electrode Div. In 1968, he was promoted to assistant vice president, marketing, and in 1973 was given the tit le of assistant vice president, technical services. Reid retired from Teledyne McKay in 1981. After his retirement, Reid joined AWS as senior staff engineer. He remained with AWS until 1992, when he once again retired.

Reid was a Life Member of the So- ciety of Metals and author of more than 35 technical articles in peer re- v iewed publ icat ions and made presentations at more than 300 meetings. He was a member of the Shrewsbury Lions Club and a past president of the Kendall Lakes, Fla. Kiwanis Club.

Reid is survived by a son, Will iam F. Reid; a daughter, Barbara L. Gel- berd; and a grandson, Nathan J. Reid.

Charles A. Babbitt

Charles A. Babbitt lAWS], an AWS Life Member since 1980, died on Octo- ber 28, 1999, in California.

Babbitt began his welding career in the late 1920s. He worked as a template maker, fitter and manual arc welder at four different steel companies until Western Pipe and Steel made him an automatic welding machine operator. In 1931, he became automatic welding foreman of the pipe fabrication department. While in this position, Babbitt

WELDING JOURNAL 181

worked on the design of submerged arc fluxes and patented tandem arc welding.

In 1948, Babbitt established the Cal- Metal Corp. to manufacture pipe for a project he was awarded, and, later, he founded Torrance Engineering and Manufacturing to produce pipe manufactur ing equipment. Eventually, 53 pipe mil ls were bui l t and shipped to 21 countries throughout the world.

Babbitt was a past chairman of the AWS Los Angeles Section. He was awarded the District Meritorious Award in 1958, 25-Year Silver Certificate and the 50-Year Silver Cer-

tificate. He was also a member of the Amer- ican Society of Mechanical Engineers (ASME).

Babbitt is survived by his wife, Jean; son, Charles; stepdaughter, Marty; and sisters, Edith and Eunice.

Ernest Crone Knoy

Ernest Crone Knoy, an engineer and business owner, died on March 26.

Knoy was nationally renowned for his engineering expertise in the water storage

industry. He founded Tank Industry Consul- tants, a firm special iz ing in steel and con- crete structures, in 1979. Previously, he served as vice president of operations and a member of the board of directors for Uni- versal Tank and Iron Works. Whi le working there, Knoy codesigned a prototype for a double-wal led family fal lout shelter now on display at the Smithsonian Institution in Washington, D.C.

Knoy is survived by his wife, Cynthia; chi ldren, Edward, Timothy, Wi l l iam, Joan and Beth; brother, Zane; sister, Mer i l yn Johnston; and four grandchildren.

A D V E R T I S E R I N D E X

ABICOR Binzel ............................... 10 Air Products ..................................... 13 Arc Machines ................................... 25 Astro Arc .......................................... 74 AWS ............................ 24,33,34,48,82 Bernard Welding Equipment .......... IFC Bug-O Systems ..................... 21,23,25 Cor-Met .................................. 27,51 Diamond Ground ............................. 27 Dual Draw ........................................ 53 ESAB Welding & Cutting Systems ...OBC F&M Marco ....................................... 3 G.A.L. Gage ...................................... 8 Generico ......................................... 17 Hobart Institute ................................ 22 Hornell Speedglas ........................... 76 Jetline Engineering .......................... 75 J.P. Nissen ...................................... 21 Koike Aronson ................................. 23 La-Co Markal ................................... 33 Lincoln Electric Co ........................... 19 Metal Processing Systems .............. 74 Miller Electric Mfg. Co ............... 6&7,30 MQ Power Corp ............................... 54 National Standard ............................ 15 Oerlikon Welding Limited ................... 2 Pferd ................................................. 1 Ransome Co ..................................... 4 Sciaky2 ............................................. 8 Superior Glove Works ...................... 42 Tech South Power Point .................. 29 Tecnar ............................................. 40 Thermco .......................................... 52 Thermographic Measurements Co. .52 T.J. Clark ......................................... 53 Victor Equipment Co ...................... I BC Wall Colmonoy Corp ........................ 77

IFC = Inside Front Cover IBC = Inside Back Cover OBC = Outside Back Cover

PREPARE FOR THE

¢HALLENG OF THE FUTURE

WITH AWS Z Prepare your company to be a leader in the welding industry. Partner with AWS and your

employees can be more competent and qualified. AWS prepares individuals to take advantage of the latest technical trends in the welding industry.

AWS is the business partner that works to keep your company competitive. Our Certification and Education programs provide practical and cost-effective professional development options. Your company benefits from presenting AWS as the authority on welding- related professional development opportunities.

In addition, AWS in-House Training programs are identical in every way to our education and certification programs held across the country. Except we bring them to your employees at the time and place that's convenient for your company! For example, we can modify the four components of our 5-day Welding Seminar in any way you choose.

IVtsether you have an immediate or long term training need, AWS can provide options.

Call Anna Petroski, AWS Business Development, at 800-443-9353, extension 481, and prepare your company for the challenges of the future!

@ American Welding ~ciety 5:,0 NW I,eJeune Rd., Miami, FI. 3:;126

hlip://www.aws.org 82 [ M A Y 2000

C l a s s i f i e d s

Welding Engineering Technology Tenure-Track Faculty College of Technology :~ Ferris State University

Teach undergraduate-level lecture/laboratory coursework in a design- and process-oriented, hands-on, BS degree Engineering Technology program. May also teach other undergraduate technical courses within the college. The successful candidate will have a broad background in welding processes, procedures, metallurgy and design. Requires the development and delivery of lectures; demonstration of processes, procedures, equipment; and maintainance of laboratory facilities. Other responsibilities include assisting in program development and equipment selection; performing academic advising; recruiting students to the program; serving on department, college and university committees; participating in a faculty team envi- roment; and maintaining a working relationship with the welding industry. A professional development plan will be maintained, as well as active membership in the American Welding Society.

Qualifications - - MS degree in engineering, engineering technology, or related field. At least three years of experience in welding design, engineering, education or research. A strong background in metallurgy and material science related to welding is required. Additional requirements include experience in welding processes, weldment design, destructive and nondestructive weld evaluation, and mechanical testing. Ability to demonstate manual welding processes preferred.

Review of applications will begin 5/15/00 and continue until position is f i l led. Send resume, letter of appl icat ion, three current letters of reference with tele- 3hone numbers, and off icial transcripts to

J O B C O D E A W S - 1 2 9 0 , H u m a n Resource D e v e l o p m e n t , Ferris State Un ivers i ty , 4 2 0 O a k Street , PRK 1 5 0 , Big Rapids, M I 49307

For more information about Ferris State University, please visit our Web site at www.ferris.edu. An equal emploment/affirmative action employer.

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U S - M D - B a l t i m o r e Senior Welding Engineer

Baltimore Gas and Electric Company, a member of the Constellation Energy Group, is seeking a Senior Welding Engineer to support its Fossil Energy Division. The successful candidate will be responsible for administering the welding program. Requirements include a thorough understanding of welding, metallurgy and applicable industry regulatory codes. The individual must have effective communication skills to in- teract with management, professionals and craft personnel. Responsibilities include designing weld repairs to service degraded components, development of new procedures to support customers, and root cause analysis of failed welds. Program management skills are necessary. Initia- tive and teamwork are essential. This position requires a BS degree in Welding Engineering, Ma- terials Engineering or equivalent degree, plus 7 years of experience.

BGE offers a stimulating and professional environment, advancement opportunity based on merit, professional development, competitive salaries, and a comprehensive benefits package. For immediate consideration, please send your resume and salary requirements to:

Baltimore Gas and Electric Company Fort Smallwood Road Complex, 2FL HR Services - Generation (GCD) 1OOO Brandon Shores Road Baltimore, MD 21226 E I O I E I M I F I D I V [email protected]

Large publicly funded NYC design and construction agency seeks Technical Inspectors. Inspectors will conduct field inspections; prepare detailed inspection reports, review laboratory tests to ensure materials meet specifications. Emphasis on welding field inspections as well as preparation of written re- )arts on welding projects. Candidates will possess a high school or general education diploma from an accredited program and 8 years of relevant building construction experience - 4 years must have been in the areas of inspection or quality assurance. Day and night shifts available. Competitive salary end benefits package. Welders must be certified by the Ameri-

can Welding Society. Send resume and salary requirements to

[email protected] or by mail to NYC School Construc- tion Authority, 30-30 Thomson Avenue, Long Island City, NY 11101. Attn: Human Resources. EOE

I

W E L D I N G E N G I N E E R I N G Immediate opening for engineers with 15+

years experience in the areas of welding metallurgy, welding process, material characterization, laser welding and failure analysis.

Candidates must have MS or PhD in welding engineering and previous journal publication experience, Background in AWS Welding Codes/Procedures, Arc Welding, Teaching/Lec- turing and Mechanical Design desirable. Excel- lent benefits and salary.Send resume to

CANDID LOGIC INC. Attn: Weld Lab Manager

P.O. Box 71943 Madison Heights, MI 48071-0943


EMPLOYMENT OPPORTUNITIES

i i i i i ¸

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thorough knowledge of welding ~ technology and 3-12 years-experience required. Knowledge of NDT, practical shop and field fabrication experience, and communication skills are required. Have or able to qualify for AWS QC-1 certification. Must be or have been a qualified welder. Signifi= cant travel required.

Your Challenges This position offers growth potentiaHd ;~' both the materials area and the :~:':~ ' : . broader engineering field. ,~ :

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Companies pay all costs. Send resume in con- fidence to

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~ Welding Supply Company I

Machine & Welding Supply Company has been a leading distributor of gases and welding supplies throughout the Carolinas since 1954. We are interested in attracting Sales Representatives and Managers with experience in the welding supply industry and a desire to excel. If you wish to work for a growing company with career opportunities in sales and management with a willingness to invest in its employees, please send a resume to Machine & Welding Supply Company, Department of Human Resources, P.O. Box 1708, Dunn, NC 28335, or send e-mail to jbb @ mwsc.com, or call 800-571-1583 ext. 208 and ask for Jimmy Blalock. We are an Equal Opportunity Employer.

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84 I MAY 2000

The Delft University of Technology (TU Delft) is work ing ha rd to forge a l ink b e t w e e n science a n d society. Now more than ever, a solid scientific foundat ion is essential to solve the problems fac ing society a n d to adequa t e ly r e spond to the fa r - reach ing deve lopments of recent years . TU Delft has t aken a l ead ing role in mee t ing the chal lenge , str iving to incorpora te a n extra d imens ion into its activities in r e sea rch a n d educat ion . In addi t ion to deve lop ing basic knowledge , this a p p r o a c h increas ingly recognises the impor tance of the

, ~" l ' \ / appl icat ion of knowledge a n d research, c rea t ing the ideal env i ronment for those who wish - " to fur ther develop their skills a n d e x p a n d their horizons.

~ ~ ~ The Faculty of Applied Sciences, one of TU Delft 's seven faculties, is compr i sed of the depar tments of Biotechnology, Materials Science, Chemical Technology and Applied Physics.

~ • Each d e p a r t m e n t is involved in both educa t iona l a n d r e sea rch activities. A common foundat ion cur r icu lum is offered for all s tudents within the faculty. Where possible, the var ious depa r tmen t s work toge ther on resea rch activities. Safe, clean, sus ta inable processes a n d products fea ture prominent ly in both t each ing a n d research.

I]:1: ;or Fechnology pology e Materials ~t within the

Faculty of Applied Sciences. The common themes addressed by the Materials Science Department are the evolution of the microstructure, studied both from a fundamental and a technological point of view, and its relation to materials properties. Research and applications in materials technology focus primarily on metals and polymers with some additional activities focused on inorganic materials.

Within the field of jo ining technology a g rea t var ie ty of different disciplines a n d sub-discipl ines have developed, incorpora- t ing e lements of physics, chemistry, mechan ica l eng inee r ing a n d mater ia ls science. The mulf idiscipl inary cha rac t e r of jo ining technology is a direct consequence of the wide r a n g e of processes , mater ia ls a n d scale cons idera t ions encoun te r ed in jo ining appl icat ions. The Jo in ing Technology Group focuses on obta in ing f u n d a m e n t a l k n o w l e d g e abou t phys ica l p h e n o m e n a of exist ing a n d n e w joining processes, with a n emphas i s on welding. In addi t ion to s tudies r e g a r d i n g the "weldabi l i ty" of materials , the current p r o g r a m m e is invest igat ing the au tomat ion a n d sens ing of jo ining processes. A new, rapidly deve lop ing a rea of resea rch is laser welding. Envi ronmenta l issues are also p lay ing a n increas ingly p rominen t role in the deve lopment of n e w we ld ing technology, a n d will cont inue to do so.

The g roup current ly consists of 2 staff scientists, 2 post-docs, 2 technic ians a n d 4 PhD students . The g r o u p possesses s t anda rd arc we ld ing equ ipment , equip- men t for solid s tate bonding, a 500 W a n d a 3 kW Nd-Yag laser, a Gleeble the rmal s imulator a n d NDT equipment .

The position You will be responsible for an educa t iona l p r o g r a m m e consist ing of courses on jo ining techniques , we ld ing technology, nondestruct ive test ing a n d mater ia ls science. You will be c h a r g e d with the deve lopmen t a n d direction of r e sea rch p rog rammes , inc luding the supervis ion a n d g u i d a n c e of MSc a n d Ph.D. s tudents , a n d will be expec ted to secure funding, par t icular ly from external sources, for both independent a n d col laborat ive resea rch activities. You will m a n a g e the scientific a n d technica l staff, a n d will have responsibi l i ty for the

maintenance of world class research facilities. In addi t ion you will have m a n a g e m e n t responsibil i t ies within the d e p a r t m e n t a n d the Facul ty of Appl ied Sciences.

Personal profile Ideally, you have ea rned a Ph.D. deg ree in mater ia ls science, physics or mechan ica l eng inee r ing a n d have ample pract ical exper ience in the field of mater ia ls science and /o r process technology, inc lud ing exper ience in a n industr ia l envi ronment . You also have s ignif icant exper ience as a resea rch scientist a n d a p ro found interest in the combina t ion of f u n d a m e n t a l a n d appl ied research. You c a n point to publ i- cat ions in scientific a n d professional journals as ev idence of your k n o w l e d g e of theory and apphcat ion in the field of joining technology.

TU Delft offers The condi t ions of emp loymen t a n d sa lary conform to the provisions of the collective bargain ing agreement for Dutch universities.

Application Please s end your appl icat ion letter (indi- ca t ing TNWOO69}, toge the r with a curr icu- lum vi tae a n d a list of publ icat ions to the Personnel Depa r tmen t of the Facul ty of Appl ied Sciences, Delft University of Technology, P.O. Box 5045, 2600 GA Delft, The Nether lands .

Information Information abou t the chair can be obtained from Prof. dr. ir. S. van der Zwaag, tel. +31 15 278 22 48 {secretary +31 15 278 39 76), fax. +31 15 278 67 30, e-mail: S .vanderZwaag@tnw. tudel f t .n l . An extensive profile is avai lable upon request .

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86 I MAY 2000

W E L D I N G R E S E A R C H

SUPPLEMENT TO THE WELDING JOURNAL, MAY 2000 Sponsored by the American Welding Society and the Welding Research Council

Partially Melted Zone in Aluminum Welds Liquation Mechanism and Directional

Solidification

Liquation is initiated eutectically and intensified by melting above the eutectic temperature, and the resultant liquid solidifies upward and toward the weld regard-

less of its position relative to the weld

BY C. HUANG AND S. KOU

ABSTRACT. Aluminum Alloy 2219 was welded by gas metal arc welding and the microstructure was examined in the partially melted zone (PMZ), which is a narrow region immediately outside the fusion zone. Extensive liquation was observed at three different locations: at large 0 (AI2Cu) particles, along grain boundaries (GBs) and at numerous isolated points within grains. Liquation was initiated at the eutectic temperature TE, by the eutectic reaction a + 0 --> L E and intensified by further melting, above TE, of the (z matrix surrounding the eutectic liquid (LE). The microstructure of the liquated-and-solidified GB material is in- triguing. First, the material consisted of a new GB of mostly thin, divorced eutectic and a eutectic-free strip of a immediately next to it. Second, within an individual grain, the strip was along the top and the side facing the weld. Third, with respect to the weld, the strip was always behind the new GB. These three characteristics point to an important phenomenon, that is, solidification of the liquated GB is directional - - upward and toward the weld, as a result of the temperature gradients across the PMZ. A thin, brittle eutectic GB and a soft ductile a strip side by side are expected to be much weaker than a normal GB before welding.

C. HUANG and S. KOU are with the Depart- ment of Materials Science and Engineering, University of Wisconsin, Madison, Wis.

Introduction

Aluminum alloys tend to be susceptible to liquation along GBs during welding in a very narrow region immediately outside the fusion zone called the partially melted zone (PMZ) (Ref. 1). Grain boundary liquation in aluminum welds can have a serious consequence-- it can make the PMZ susceptible to hot cracking (intergranular) during welding or ductility loss after welding. Liquated GBs are obviously weak and can be torn by tensile stresses induced during welding. Most studies on PMZ liquation in aluminum welds focused on the susceptibil- ity to hot cracking during welding (Refs. 2-7). However, even if hot cracking is avoided during welding, the PMZ can still be susceptible to ductility loss after welding, as observed in tensile testing of the resultant welds (Refs. 8-10).

KEY WORDS

Aluminum Alloys Grain Boundaries Gas Metal Arc Welding Liquation Eutectic Partially Melted Zone (PMZ)

Unlike steels or nickel-based superal- Ioys, little, if any, has been reported about the mechanism of welding-induced GB liquation in wrought aluminum alloys or about the GB microstructure after liquation. As aluminum alloys are gaining popularity (e.g., in the auto industry) it is essential to better understand the welding of them.

Experimental Procedure

The workpiece was Alloy 2219, a high-strength aluminum alloy often used for aerospace applications. The actual composition of the workpiece was AI- 6.33%Cu-0.34%Mn-0.13%Fe-0.12%Zr- 0.07%V-0.06%Si-0.04%Ti-0.02%Zn by weight. It was selected because it is essentially a binary alloy of AI-6.3wt-%Cu and its microstructure is, therefore, fairly easy to understand. The dimensions of the workpiece were 20 cm by 10 cm by 6.4 mm. It was welded in the as-received condition of T851. T8 stands for solution heat treating, cold working and followed by artificially aging, and T51 stands for stress relieving by stretching (Ref. 11).

Two bead-on-plate welds were made in the same workpiece by gas metal arc welding (GMAW), one perpendicular to the rolling direction and the other parallel. The welding parameters were 6.35 mm/s (15 in./min) welding speed, 25.5 V arc voltage, 190 A average current and argon shielding. The filler metal was an Alloy 2319 wire of 1.2-mm diameter. Its actual composition was AI-6.3%Cu-

WELDING RESEARCH SUPPLEMENT I 113-s

8 0 0 , , , , , ,

7 0 0 S o l i d u s L i q u i d u s L

o o o .

' c~+ O---~ L atTE= 548°C 00- 500 ~ / ~a (S.65)

P- ! 0 4

400

3 0 0

0

AI

( Z + 0 (AI2Cu)

, , , i . . . . . . . . . i . . . . . . . . . i . . . . . . . . . i . . . . . . . . . , , , 6.3 10 20 30 4 0 50

Weight Percent Copper 60 Fig. 2 - - Partially mel ted zone in a GMA we ld in 2219

a luminum alloy.

Fig. 1 - - AI-Cu phase diagram (Ref. 12).

0.3 %Mn-0.18%Zr-0.15 %Ti-0.15%Fe- 0.10%V-0.10%Si, which is higher in Zr and Ti than Alloy 2219. The wire feed speed was 13.5 cm/s (320 in./min).

After welding, the microstructure near the weld was examined by optical microscopy and by scanning electron microscopy with a secondary electron image. Several etching solutions, including Keller's, were tried, and the solution of 0.5 vol-% HF in water was found most satisfactory.

Results and Discussion

Overview of Partially Melted Zone

For convenience of discussion, the aluminum-rich portion of the AI-Cu phase diagram (Ref. 12) is shown in Fig. 1. The big gap between the solidus line and the liquidus line indicates the Cu content of the c~ phase (AI-rich solid) is much lower than that of the liquid. Since the 6.3% Cu content is about 20 times higher, or more than the content of any other alloying element, Alloy 2219 can be considered as a binary alloy of AI- 6.3% Cu as an approximation.

Figure 2 is an optical micrograph showing an overview of the PMZ. The PMZ includes the region in which the GBs appear lighter in color. According to the AI-Cu phase diagram (Fig. 1), the liquation zone is in the narrow region immediately outside the fusion zone, where the maximum temperature experienced during welding ranges from the liquidus temperature of about 642°C on the fusion zone side (right) to the eutectic temperature of 548°C on the base metal side (left).

Base Metal

A scanning electron micrograph of the base metal is shown in Fig. 3A. Large particles are present both within grains and at GBs. Electron probe microanaly- sis (EPMA-WDS) indicates the AI/Cu weight ratio (e.g., 53/46) of these particles is close to that of about 53/47 for 0 (AI2Cu) - - Fig. 1. As an approximation, these particles will be considered as the 0 phase even though they may contain very small amounts of other elements as well. As already mentioned, Alloy 2219 will be considered as a binary alloy of Al- 6.3% Cu as an approximation. Figure 3A also shows several small 0 particles within grains.

The small particles along the GBs are believed to be the 0 phase also, although they are too small to be analyzed by EPMA. It is not clear why the GBs are not fully loaded with these small particles. The GBs do not look much different without etching.

The eutectic liquid during the termi- nal stage of solidification in ingot casting solidifies and forms large and small eutectic particles, along GBs and within grains. The solution heat-treating temperature for Alloy 2219 is 535°C (Ref. 13). From the phase diagram (Fig. 1 ), the base metal is expected to consist of a 0 matrix plus additional undissolved 0 (AI2Cu) particles (Ref. 14). During solution heat treating of the ingot, the large eutectic islands decompose into large 0 particles and c(, which is connected to and hence indistinguishable from the c( matrix. During rolling of the ingot into plates or sheets, some of the large 0 particles are displaced or even fractured. Like the large eutectic particles, the GB

eutectic also decomposes into 0 particles and (~, but this occurs much more rapidly in view of the smaller size and hence shorter distance required for diffusion. The presence of the large 0 particles is an indication that the much smaller eutectic particles along GBs and within grains have already decomposed into 0 and oz.

Liquation at Large 0 Particles

A scanning electron micrograph of the PMZ is shown in Fig. 3B. The two large particles within the grains do not look like the large 0 particles within the grains of the base metal - - Fig. 3A. Rather, their composite-like structure indicates they are eutectic. This suggests that in the PMZ the large 0 particles within grains react with the surrounding c~ matrix to become liquid, which upon solidification forms large eutectic particles within grains. In other words, liquation occurs at large 0 particles in the PMZ by the eutectic reaction (~ + 0 ~ LE, where L E is eutectic liquid.

Another scanning electron micrograph of the PMZ is shown in Fig. 3C. Large eutectic particles are present both within grains and at GBs, just like the large 0 particles before welding - - Fig. 3A. This again suggests that in the PMZ the large 0 particles react eutectically with the surrounding c( matrix to become liquid and form large eutectic particles upon solidification.

Constitutional liquation was first discovered by Pepe and Savage (Refs. 15, 16) in Maraging steel and later observed in Ni-based superalloys (Refs. 17-22) as well. This constitutional liquation and the liquation in the 2219 aluminum welds are both initiated at the eutectic temperature. They, however, differ from each other significantly in the following way. As pointed out by Pepe and Savage

114-s [ MAY 2000

(Refs. 15, 16), liquation is initiated before the solid-plus-liquid region of the phase diagram is reached during heating. It occurs only if the heating rate is rapid enough to prevent the second-phase particles (titanium sulfide) from dissolving in the single-phase region of the phase diagram. The liquation in the 2219 aluminum welds, however, is initiated simply because the solid-plus-liquid region of the phase diagram is reached during heating. It occurs even without a rapid heating rate.

Figure 4A shows an optical micrograph of the base metal, where the peak temperature during welding is well below the eutectic temperature T E. Large e particles (white) are present both within grains and at GBs. The distribution of large e particles is not exactly uniform, and there are more of them in the area covered by this micrograph than in other areas of the base metal.

Figure 4B, shows an optical micrograph at the edge of the PMZ facing the base metal. The large particles on the left (e) are still the e phase, similar to those in Fig. 4A. The local temperature is, therefore, below T E. The large particles (E) to the right of the large e particles, however, are eutectic, and the local temperature is, therefore, above T E. These large eutectic particles come from the large e particles that have reacted with the surrounding 0~ phase to form eutectic liquid. This eutectic liquid solidifies without changing its composition. Therefore, Fig. 4B represents the location where the peak temperature during welding is the eutectic temperature T E. The arrows indicate the GBs that have become eutectic. The e particles and one eutectic particle are en- larged in Fig. 4C to show the difference in the microstructure more clearly.

Figure 4D is another optical micrograph at T E. The eutectic particles (E) are on the average larger than the e particles (e) in the same photo. In fact, a e particle should expand after it reacts with the surrounding (z phase to become eutectic liquid. Again, the arrows indicate the GBs that have become eutectic.

Figure 4E is an optical micrograph of the PMZ, where the peak temperature during welding is above the eutectic temperature T E. Large eutectic particles are present within grains. This time they are surrounded essentially by a wide light- etching, eutectic-free material of the (z phase. The large eutectic particles within grains shown previously in Fig. 3B and C are, in fact, similar in this respect except that the surrounding (z phase does not appear any lighter in color under the scanning electron microscope. The presence of this ~ phase is explained below.

As already mentioned, when the peak

GB-

Cz

GB- O~

GB

c~

Fig. 3 - - Scanning electron micrographs. A - - Base metal; B and C - - part ial ly melted zone. Transverse cross section o f weld made perpendicular to the ro l l ing direction.

temperature reaches the eutectic temperature TE, the large e particles react with the cz phase and form eutectic liquid. Re- ferring to the phase diagram in Fig. 1, the fraction of the liquid is ad / ae according to the lever rule. When the peak temperature rises above TE, the composition of the liquid changes along the liquidus line from point e at T E to significantly above TE, say, point f. The fraction of the liquid, bg / bf , is much greater than ad / ae . In other words, liquation is intensified by further melting of the o( matrix surrounding the liquid. The liquid has now changed from eutectic to hypoeutectic in composition, and the large decrease in the Cu content of the liquid is achieved by melting the surrounding (z phase of a

much lower Cu content. Upon cooling, the hypoeutectic liquid solidifies initially as the (z phase and finally as eutectic when T E is reached. This is why the large eutectic particles are surrounded by the o~ phase. The fraction of the liquid that solidifies as eutectic, however, is expected to be greater than that based on the lever rule, that is, ad / ae . This is further explained as follows.

Since diffusion in solid is orders of magnitude slower than diffusion in liquid, the changes in the average composition of the (z phase around the liquid are slower or less than those given by the solidus line. For instance, upon heating, the average composition of the (z phase around the liquid can decrease from point a at T E

WELDING RESEARCH SUPPLEMENT[ 115-S

Fig. 4 - - Opt ical micrographs. A - - Base metal; B through D - - edge o f part ial ly melted zone; E and F - - part ial ly melted zone; G - - fusion zone. The arrows in B and D indicate the GBs that have become eutectic.

to point b above T E. Upon cooling, it can increase from point b above T E to point c at T E. As such, at T E the fraction of eutectic is cd /ce , which is greater than ad / ae.

Figure 4F shows four large eutectic particles along GBs and the c( phase surrounding them. Like the large eutectic particles within grains (Fig. 4E), hypoeutectic liquid was present at the locations of these particles above T E. Upon cooling, it solidified as the phase above the eutectic temperature T E and resulted in the light-etching, eutectic-free material

surrounding the eutectic particles. It finally solidified as eutectic at T E and resulted in the large eutectic particles. Two large eutectic particles are also present at GBs in Fig. 3C (one near the bottom and the other near the upper right corner).

If any unreacted residual of a large 0 particle were left at a peak temperature above TE, it would have been surrounded by a liquid layer ranging from hypereutec- tic on the 0 side to hypoeutectic on the (~- matrix side, according to the phase diagram. Upon cooling, 0 would grow outward and c( inward until the liquid in between became eutectic at T E and solidified as such. The resultant structure would have been a 0 core surrounded first by eutectic and then by Cu-depleted oz. Such a structure with a 0 core, however, does not appear to match that of large eutectic particles in the PMZ - - Fig. 4E and F.

In summary, liquation at large 0 parti-

l16-s I MAY 2000

cles in the PMZ appears to be initiated by the eutectic reaction (~ + e --> L E at the eutectic temperature TE, and intensified by further melting of the surrounding c( phase above T E.

Liquation at Grain Boundaries

Figures 3B and C show that, in the PMZ, GBs appear to be eutectic - - divorced eutectic where the GB eutectic is thin and normal eutectic where it is thicker. In the former case, the c( phase of the eutectic grows upon and is, therefore, indistinguishable from the primary (z of the matrix, leaving e alone visible at the GBs. In the latter, the GB eutectic shows the normal composite-like structure of ((~ + e). The formation of GB eutectic is explained below.

As shown previously in Fig. 3A, small 0 particles are present along GBs before welding. At the edge of the PMZ facing the base metal (Fig. 4B and D), the peak temperature during welding is T E. Here, GB 8 particles react eutectically with the surrounding c~ phase and form a thin liquid-eutectic GB film. Upon cooling, itso- lidifies as solid eutectic along GBs, as shown by the arrows in Fig. 4B and D. This GB eutectic is thin and hence more likely to be divorced than normal.

In the PMZ, however, the peak temperature during welding is above T E. Here, the GBs are severely liquated, as shown in Fig. 4E. The GB eutectic appears to be mostly divorced, as mentioned previously (Fig. 3B and C). Adja- cent to each GB is essentially a light-etching, eutectic-free strip of the (~ phase. Similar strips are, in fact, also present in Fig. 3B and C, except they do not look any lighter in color under the scanning electron microscope. The presence of an c~ strip along the GB is also evident in Fig. 4F. The reason for the presence of an c( strip next to the GB eutectic is similar to that for the presence of the (~ phase surrounding the large eutectic particles within grains - - Fig. 4E.

As already mentioned, when the peak temperature reaches the eutectic temperature TE, the small e particles along GBs react with the surrounding c( phase and form a eutectic GB liquid. Referring again to the phase diagram in Fig. 1, when the peak temperature rises above TE, the composition of the grain boundary liquid changes along the liquidus line from point e to, say, point f. Liquation in- tensifies as the fraction of the liquid rises significantly from ad/ae tO -bg/E[. The large decrease in the Cu content of the GB liquid is achieved by melting the surrounding (z phase of a much lower Cu content. Upon cooling, the hypoeutectic GB liquid solidifies initially as the ~ phase and

Liquation Mechanism

base m e t a l partially-melted \ \ fusion (2219 AI) zone ~ \ zone

c~ : Cu-depleted solid / /\T\ LE: eutectic liquid / / | LH: hypoeutectic liquid//" ~ / E :eutectic solid ~ ~ / e: AI2Cu T<TE T=TE T>TE

during ~ii~ i!~iii:~i~ i~ilk ~ i i ~ @ ~! iili ...... ~i::iii~i ii .... ,- .................................

welding (a) ~ (b)" ~ (c)# ~

. . . . . . . . .

w e d ng ~ ; i ii!!~i i!~:~

(d) (e) (f)

* Liquation initiated at T E by c~ + 0--~ L E

# Liquation intensified by melting of (~ matrix above T E

Fig. 5 - - Schematic sketch showing the liquation mechanism in the partially melted zone.

finally as eutectic when T E is reached. This explains why the GB eutectic is accompanied by a strip of the c( phase.

One might suspect that Cu segregation to the GB by solid-state diffusion caused GB liquation. This liquation mechanism, however, raises the following questions. Why does Cu diffuse to the GB? Since the (~ strip appears on only one side of the GB (Figs. 3B, 3C, 4E and 4F), why does Cu diffuse to the GB from only one side? Furthermore, how can liquation within grains be explained?

Suppose within a narrow strip along the GB, Cu diffuses to the GB and causes it to melt. This solid-state diffusion leaves behind a Cu-depleted c( strip along the GB (EPMA confirms Cu depletion in the (~ strip). Based on Figs. 3B, 3C, 4E and 4F, the c~ strips are about 10 pm (1 x 10 -3 cm) wide. As an approximation, x = qDt, where x is the diffusion distance, D the diffusion coefficient and t the diffusion time. The diffusion coefficient for Cu in solid AI containing up to 3.5 wt-% Cu at around 600°C is about 1 x 10 -8 cm2/s (Refs. 14, 23). Based on these approximations, the time required for diffusion is 100 s. Obviously, this is far longer than the time the PMZ can possibly stay above

the eutectic temperature during welding. Therefore, Cu segregation is not expected to be the mechanism for GB liquation.

It should be emphasized the equilib- rium partition coefficient, k, for Cu in AI- 6.3%Cu alloy is less than unity. Approx- imately, k = 5.65/33.2 = 0.1 70. Consequently, as the GB liquid solidifies, Cu is rejected into the liquid to cause severe Cu segregation. According to the PMZ micrographs shown in Figs. 3B, 3C, 4E and 41=, the GB liquid solidifies with the planar solidification mode. Initially, the solid has a very low Cu con- centration. As solidification proceeds, however, Cu continues to be rejected into the liquid ahead of the planar solidification front. Eventually, the liquid becomes eutectic and solidifies as the eutectic GB. This is why there is a light-etching, Cu-depleted c( strip right next to the eutectic GB. This strip is wide because, as already mentioned, the fraction of the liquid in the PMZ increases significantly with increasing temperature, e.g., from ad/ae at T E to bg/bfabove T E - - Fig. 1. EPMA has confirmed severe Cu segregation from the (~ strip to the GB, as will be reported elsewhere.

The wide light-etching regions of Cu-


roiling d i r e c t i o n ~

Fig. 6 - - Opt ical micrographs o f the transverse cross section o f the part ia l ly mel ted zone o f a weld made perpendicular to the ro l l ing direction. A - - Left; B - - right; C - - bottom.

depleted 0c both next to GBs and surrounding large eutectic particles represent the areas that were completely melted. This is not just an etching effect. Both the SEM and EPMA electron micrographs of an unetched PMZ show wide c( regions similar to that of the light-etching, Cu-depleted regions in the optical micrographs of an etched PMZ. Further- more, in the fusion zone, the regions next to the eutectic are also light etching, as shown in Fig. 4G. These regions were melted during welding.

Consider the case, if it does exist, that a certain portion of the GB does not have any small e particles. The GB liquid can still reach here from adjacent areas of the same GB. Even if this does not happen, liquation can still occur when the local temperature rises above T E to cause the (z phase to melt. GB eutectic can still form during cooling, similar to path bc shown in Fig. 1.

In summary, referring to GBs along which small e particles are present, GB liquation in the PMZ is initiated by the

eutectic reaction (~ + 0 --> L E at the eutectic temperature T E and intensified by further melting of the adjacent ~ phase above T E.

Figure 5 summarizes the constitutional liquation at large e particles and along GBs in the PMZ of a 2219 aluminum weld.

Liquation at Numerous Isolated Points within Grains

Figures 4E and F show there are numerous small particles (round and dot- like) at isolated points within grains. These particles are believed to be eutectic and caused by liquation. The scanning electron micrographs in Fig. 3B and C also show such particles, but fewer. Presum- ably, only the larger ones are visible. Per- haps, with scanning electron microscopy, the color contrast of smaller particles against the o~ matrix is more limited.

Figures 4A through D show the presence of numerous small particles within grains in the base metal. These are likely to be the e particles originating from the small eutectic particles within grains after casting. As mentioned previously, during theterminal stage of solidification in ingot casting, eutectic liquid is present in the numerous interdendritic spaces. During solution heat treating of the ingot, the interdendritic eutectic particles can decompose into 0 and c(. During rolling, the particles can be fractured and displaced, resulting in numerous small 0 particles within grains. These small 0 particles are not visible in Fig. 3A possibly because of the more limited color contrast in scanning electron microscopy again.

Upon heating to the eutectic temperature during welding, these 0 particles react with the surrounding @ matrix and form eutectic liquid, similar to the large e particles and the small GB 0 particles - - Fig. 3A. Upon further heating to above the eutectic temperature, the liquid reduces its Cu content by melting the surrounding 0~ phase of a much lower Cu content. Upon cooling, the hypoeutectic liquid first solidifies as ~ and finally as eutectic. Most of the resultant eutectic particles are expected to be divorced in view of their very small size. From Fig. 4E and F, almost all the round particles that are large enough to be seen more clearly appear to be divorced eutectic.

Directional Solidification

The microstructure of the liquated- and-solidified GB material has some interesting and significant characteristics that have not been reported previously. First, as already described, the material consists of a new GB and an c~ strip im-

118-s I MAY 2000

Fig. 7 - - Opt ica l micrographs o f the transverse cross section o f the par t ia l ly mel ted zone o f a we ld made paral le l to the ro l l ing direction. A - - Left; B - - right.

Fig. 8 - - Opt ica l micrographs showing top views o f the par t ia l ly mel ted zone o f a we ld made paral le l to the ro l l ing direction. A - - One side; B - - opposite side.

mediately next to it, the former being eutectic and the latter eutectic free. Second, within an individual grain the (x strip is always along the top and the side facing the weld. Third, with respect to the weld, the c( strip is always behind the new GB.

The second characteristic is evident in the weld made perpendicular to the rolling direction. Figure 6A is a PMZ micrograph on the left of the weld. Within a grain the (x strip is present at the top and along the right side of the grain. Figure 6B, on the other hand, is a PMZ micrograph on the right of the weld. The 0c strip is at the top and along the left side of a grain. A PMZ micrograph at the bottom of the weld is shown in Fig. 6C. The c( strip is at the top of a grain.

The second characteristic is also evident in the weld made parallel to the rolling direction, as shown in Figs. 7 and 8. In Fig. 7A, the strip is along the top and the right side of a grain, and in Fig. 7B it is along the top and the left side of a grain. In Fig. 8A, within an individual grain, the strip is along the side of the grain that faces the weld. The same is true

in the micrograph in Fig. 8B. The third characteristic is evident in

the micrographs shown in Figs. 6-8. Within an individual grain, the light- etching strip is always on the side of the new GB that is farther away from the weld. In other words, with respect to the weld, the c( strip is always behind the new GB.

The three characteristics of the microstructure of the liquated-and-solidi- fled GB material are summarized in the schematic sketch in Fig. 9. These characteristics indicate the solidification of the liquated GB is directional. It solidifies upward and toward the weld - - instead of inward from both grains it connects. To the best of the authors' knowledge, this directional solidification behavior of a GB liquid has not been reported previously. This behavior is the result of the significant temperature gradients across the PMZ of a weld.

From the heat flow point of view, the steeper the temperature gradients, the greater the tendency for a liquid to solid- ify in the direction of increasing temper-

ature. Fourier's law of conduction can be written as q = -kVT, where q is the heat flow rate per unit area, k the thermal conductivity and VT the temperature gradient (Ref. 24). The minus sign indicates heat is extracted in the opposite direction of the temperature gradient. The higher the temperature gradient, the faster heat is extracted to cause solidification in the direction increasing temperature.

Directional solidification is also evident from the large eutectic particles surrounded by the (x phase. Figure 4E shows the three large eutectic particles are not at the center of the c~ phase. Rather, they shift upward and to the right toward the weld. The same is true with the many large eutectic particles in Fig. 6A.

Significance

Grain boundary liquation has long been known to cause hot cracking and ductility loss in the PMZ of aluminum welds. The c~ strip along the new GB is soft and ductile because it is not only eutectic free but also solute depleted. The


Directional Solidification upward and toward weld

G['~:i!/

base metal

eutectic along 7 liquated & grain boundary / solidified

I material along eutectic-freestrip of c~ _.[ grain boundary

grain interior with eutectic particles

E" eutectic solid • Cu-depleted solid

Fig. 9 - - Schematic sketch illustrating directional solidification in the partially melted zone.

GB eutectic right next to it, however, is hard and brittle. Under tensile stresses the (~ strip is much better able to yield than the GB eutectic. (Due to space lim- itation, measurements of both hardness and solute segregation and fracture of GB eutectic under tension wi l l be shown in a fol low-up report.) A thin, hard, brittle, eutectic GB accompanied by a soft, ductile (z strip is expected to be mechanically significantly inferior to a normal GB before welding. Aluminum alloys can lose duct i l i ty s igni f icant ly in the PMZ, as mentioned previously (Refs. 8-10).

Conclusions

The GMA welds of 2219 aluminum alloy show extensive liquation can occur in the PMZ of aluminum welds. For Al loy 2219, l iquation is initiated by the eutectic reaction (~ + 0 --~ L E at the eutectic temperature and intensified by melting of the surrounding (x matrix above the eutectic temperature. Liquation occurs at large 0 particles, along GBs and at numerous isolated points wi thin grains. Li- quation at large 0 particles results in large eutectic particles. Grain boundary liqua- t ion results in new GBs that are more often divorced eutectic than normal eutectic. Liquation at isolated points wi th in grains results in numerous small particles of divorced eutectic. The liquated GB so- l idif ies upward and toward the weld under the influence of the temperature

gradients across the PMZ. Such directional solidification results in a eutectic- free strip of the (x phase right below and behind the eutectic GB.

Acknowledgments

This work was supported by the Na- tional Science Foundation under Grant No. DMR-9803589. The authors are grateful to Bruce Albrecht and Todd Holverson of Mi l ler Electric Manufactur- ing Co., Appleton, Wis., for donating the welding equipment (including the Invi- sion 456P power source, and XR-M wire feeder and gun) and for their technical assistance dur ing this study. They also thank Walid Gabr-Rayan for conducting the welding experiments.

References

1. Kou, S. 1987. Welding Metallurgy. pp. 29-59, 239-262. New York, N.Y., John Wiley and Sons.

2. Robinson, I. B. 1978. The Metallurgy of Aluminum Welding. Pleasanton, Calif., Kaiser Aluminum Corp.

3. Gittos, N. F., and Scott, M. H. 1981. Heat-affected zone cracking of AI-Mg-Si alloys. Welding Journal 60(6): 95-s to 103-s.

4. Dudas, J. H., and Collins, F. R. 1966. Preventing weld cracks in high-strength aluminum alloys. Welding Journal45(6): 241-s to 249-s.

5. Lippold, J. C., Nippes, E. F., and Savage, W. F. 1977. An investigation of hot cracking in 5083-0 aluminum alloy weldments. Welding

Journal 56(6): 171 -s to 178-s. 6. Metzger, G. E. 1967. Some mechanical

properties of welds in 6061 aluminum alloy sheet. Welding Journal 46(10): 457-s to 469-s.

7. Steenbergen, J. E., and Thornton, H. R. 1970. Quantitative determination of the conditions for hot cracking during welding for aluminum alloys. Welding Journal 49(2): 61-s to 68-s.

8. Gibbs, F. E. 1966. Development of filler metals for welding AI-Zn-Mg Alloy 7039. Welding Journal 45(10): 445-s to 453-s.

9. Young, J. G. 1968. BWRA experience in the welding of aluminum-zinc-magnesium alloys. Welding Journa147(10): 451-s to 461-s.

10. Arthur, J. B. 1955. Fusion welding of 24S-T3 aluminum alloy. Welding Journal 34(11): 558-s to 569-s.

11. The Aluminum Association. 1982. Alu- minum Standards and Data. p. 15. Washing- ton, D. C., The Aluminum Association.

12. Binary Alloy phase Diagrams 1 : 106. 1986. Materials Park, Ohio, ASM Interna- tional.

13. Metals Handbook, 9th Edition, Vo[. 4, Heat treating, pp. 678-679. 1981. Materials Park, Ohio, ASM International.

14. Hatch, J. E. 1984. Aluminum: Proper- ties and Physical Metallurgy. pp. 134-135, 140. Materials Park, Ohio, ASM International.

15. Pepe, J. J., and Savage, W. F. 1967. Ef- fects of constitutional liquation in 18-Ni maraging steel weldment. Welding Journal 46(9): 411-s to 422-s.

16. Pepe, J. J., and Savage, W. F. 1970. Weld heat-affected zone of the 18Ni maraging steels. Welding Journal 49(12): 545-s to 553-s.

17. Owczarski, W. A., Duvall, D. S., and Sullivan, C. P. 1966. A model for heat-affected zone cracking in nickel-base superalloys. Welding Journal 45(4): 145-s to 155-s.

18. Duvall, D. S., and Owczarski, W. A. 1967. Further heat-affected zone studies in heat resistant nickel alloys. Welding Journal 46(9): 423-s to 432-s.

19. Savage, W. F., and Krantz, B. M. 1966. An investigation of hot cracking in Hastelloy X. Welding Journal 45(1 ): 13-s to 25-s.

20. Thompson, R. G., and Genculu, S. 1983. Microstructural evolution in the HAZ of Inconel 718 and correlation with the hot ductility test. Welding Journal 62(12): 337-s to 345-s.

21. Radhakrishnan, B., and Thompson, R. G. 1990. The kinetics of intergranular liquation in the HAZ of Alloy 718. Recent Trends in Welding Science and Technology. p. 637. ASM International, Materials Park, Ohio.

22. Radhakrishnan, B., and Thompson, R. G. 1993. Modeling of subsolidus liquation in the weld heat-affected zone. International Trends in Welding Science and Technology. p. 321, ASM International, Materials Park, Ohio.

23. Poirier, D. R., and Geiger, G. H. 1994. Transport Phenomena in Materials Processing. p. 432. The Minerals, Metals and Materials So- ciety, Warrendale, Pa.

24. Kou, S. Transport Phenomena and Ma- terials Processing. pp. 116-119. John Wiley and Sons, New York, N.Y.

120-s I/V lAY 2000

Finite Element Analysis of Heat Flow in Single-Pass Arc Welds

Thermal efficiency is used to quantify the energy made available by the arc

BY E. A. BONIFAZ

ABSTRACT. The easiest ways to simulate welding processes are with the decou- pied heat equation of Navier-Stokes or magnetohydrodynamic (MHD) equations. To decouple the heat equation, functions of energy input rate Q, heat flux per unit area (or volume) per unit time q and effective thermal conductivity Kef f that generate a temperature field by the heat equation must be considered. More precisely, the traditional heat source models (Gaussian and ellipsoidal) and Keff functions must be used cautiously because of the critical responsibility to represent the magnetohydrodynamics of the arc and the fluid mechanics of the weld pool. When thermal efficiency is introduced in the decoupled heat equation, both the complex and nonintuitive physics of the arc and dilution (through melting efficiency) are incorporated in the heat transfer analysis. This paper allows the melting efficiency to be related to the process variables in a finite element model (FEM) simulation through the energy input rate Q. Transient thermal histories and sizes of fusion and heat- affected zones are compared with numerical and measured values reported by Christensen, Krutz and Goldak using both Gaussian and ellipsoidal power density distribution functions. The FEM code COSMOS, produced by Structural Research and Analysis Corp., was used for all the simulations described in the following sections.

Introduction

Welding is a technique commonly used to join metallic parts. Examples are ubiquitous, ranging from delicate elec-

E. A. BONIFAZ is with the Materials Depart- ment, Mechanical Faculty, Escuela Polit~cnica de Chimborazo, Riobamba, Ecuador.

tronic components to very large structures. Arc welding is probably the most popular manufacturing process for joining metals used in structural applications. The critical first step in creating a science base for the design and analysis of welds is to accurately compute the transient temperature field (Ref. 1).

Figure 1 depicts the arc welding process, in which the filler metal is deposited on the substrate in the weld interface direction. Since the electrode is "suddenly" applied to a small spot on a structure, there will be an immediate response (shock response) consisting of a very steep temperature profile in the immediate vicinity of the load. At later times, the temperature profile will become smoother as the heat diffuses throughout the structure. Figure 1 also shows the fine and coarse two-dimensional (2-D) FEM grids used for computing the temperature field. Only one-half of the cross section is considered, because of symmetry.

Perhaps the most critical input data required for welding thermal analysis are the parameters necessary to describe the heat input to the weldment from the arc (Ref. 2). The problems of distortion, residual stresses, grain structure, fast cooling, high temperatures and reduced strength

KEY WORDS

Heat Transfer Thermal Conductivity Finite Element Model (FEM) Heat Input Heat Source Models

of a structure in and around a weld joint result directly from the thermal cycle caused by the localized intense heat input of fusion welding (Ref. 3). Reduc- ing the heat input to the workpiece is a primary goal for weld process selection and weld schedule development in the aerospace and electronics industries. In microwelding applications, the depth of penetration is typically less than 1.0 mm, and hermeticity rather than mechanical strength is the primary joining requirement (Ref. 4).

The quantitative understanding of convection (fluid motion) and heat flow not only in arc discharge but also in weld pools is of considerable practical interest. To solve the problem, the finite element method has been chosen for transient heat flow analysis for several reasons: It has the best capability for nonlinear analysis and dealing with complex geometry, it is the most compatible with CAD/CAM software systems and it is the best to deal with electro-thermo-elasto- plastic analysis.

A literature review of some relevant research conducted in this concern is summarized below.

Ushio and Matsuda (Ref. 5) developed a mathematical formulation to represent the electromagnetic force field in high-current DC arcs. Oreper, et aL (Ref. 6), showed that the electromagnetic and surface tension forces dominate the flow behavior, producing in some cases double circulation loops and, therefore, segregation in the weld pool. Eagar and Tsai (Refs. 7, 8) showed that both welding process variables (current, arc length and travel speed) and material parameters have significant effects on weld shape. It was also shown that arc length is the primary variable governing heat distribution and that the distribution is closely ap- proximated by a Gaussian function


/

D

m

I: t

i h

I I !

) ] l

| | m m

l l

] s

m

) ill

IIi

J

I "

ELECTRODE AT TIME t

DIRECTION Z ECTRODE TRAVEL)

W E L D INTERFACE

ANALiZEO

~ \ \ \ \ \ \

14414 C

I I I

Fig. I - - Weldment configuration and FEM grids for the thick-section, bead-on-plate weld reported by Christensen, et al. (Ref. 14), Krutz and Segerlind (Ref. 11) and Goldak, et al. (Ref. 3). Fine grid (320 elements), coarse grid (80 elements).

_~2

q(r) = q_--~O_2 exp2a2 z~a (1)

Here, qo is the maximum heat intensity and o is the distribution parameter of the heat flux. It is important to note that (~ is determined from experimental work and is expressed as a function of arc length, current and electrode tip angle.

Tekriwal, etal . (Ref. 9), used the alternative form of the Pavelic (Ref. 1 O) "disc," i.e., the moving Gaussian distribution heat source model, Equation 2, suggested by Friedman (Ref. 2), Krutz, et al. (Ref. 11), and Goldak, et al. (Ref. 3), to simulate the butt joint welding of plates with three-dimensional (3-D) models, including the deposition of weld metal:

- 3 x 2 - 3 ~ 2

2 2 q (x ,z ,t)= 3Q2e c e c

~c (2) Here Q = energy input rate (W); c = the

characteristic radius of flux distribution (m); ~ -- the transformation relating the fixed and moving coordinate system = z + v ('c - t), where v = the welding speed (m/s) and • = a lag factor = c/v (seconds).

Goldak, et al. (Reg. 3, 12, 13), proposed a three-dimensional double ellipsoidal heat flux model to examine the three-dimensional temperature, stress and strain fields, based on the profile

6~Q q(x ' Y' Z' t) = f(f 'r) abc~--~

_3×2 _3y2-3[z+v(,-*)] 2 e a2 e 82 e c2 (3)

where a, b, c = the semiaxes of the ellipsoid in the directions x, y and ~ (m).

In this model, the front half of the source is the quadrant of one ellipsoid source and the rear half is the quadrant of another ellipsoid. It is important to note that fraction values ff = 0.6 and fr = 1.4 were incorporated in Equation 3 to pro-

vide the best correspondence between the measured and calculated thermal history results (see details about the double ellipsoid model in Ref. 3).

The appropriate use of Equations 2 and 3 requires the estimation of the distribution parameters (a,b,c). Goldak, et al. (Ref. 12), suggest making cross-sectional metallographic and surface ripple markings to fit the heat source dimensions. If such data are not available, Christensen's (Ref. 14) expressions should be used.

Brown and Song (Ref. 15), using a simulated 3-D model, analyzed distortion and residual stresses of large structures. To simulate the heat flux from the arc, the Gaussian function was used because they consider less flux penetration is involved in arc welding than in high- power-density welding processes (EBW and LBW), where the double ellipsoidal heat flux model can capture the flux penetration effectively. Fuerschbach and Knorovsky (Ref. 4) and Omar and Lundin (Ref. 16) analyzed that in the high-power- density welding processes, the heat input is low and the melting efficiency high.

The above citations reveal that the term melting efficiency had never been related to the welding process variables in a FEM simulation; also, it appears that, up to the present time, the quantitative treatment to represent heat flow in arc discharge, heat flow in weld deposits (substrate and deposited filler metal) and pool convection (fluid motion) in a 3-D (nonlinear-transient) space has been limited. The reason is the difficulty to develop a meaningful relationship between theoretical models and experimental observations.

In this paper, a simple method to model the arc welding process is proposed based on the Kamala and Goldak (Ref. 1) statement that follows.

Kamala and Goldak (Ref. 1) state that whether or not the heat equation is coupled to other equations such as the Navier-Stokes or MHD equations, the temperature fields belong to the Sobolev space H 0. If the temperature fields belong to H 0, the FEM solution to the uncoupled heat equation always exists regardless of whether the heat equation is coupled or not. Therefore, in order to decouple the heat equation, it is necessary to find the Q and q functions that generate the desired temperature field. In solving the uncoupled heat equation, Q and q account for resistive heating, and i2R and Keff account for convective heat flow in the melt.

The objectives for the present work were 1) to develop a simple 2-D FEM to calculate not only the transient thermal histories but also the sizes of fusion and

122-s I MAY 2000

heat-affected zones in single-pass arc welds; and 2) to determine the effect of introducing the melting efficiency term into the energy input rate Q, i.e., Q = qal"lmVl, using both Gaussian and ellipsoidal power density distribution functions.

M o d e l i n g Considerat ions

With regard to modeling the process, the following may be noted:

1) The heat that is transferred to the workpiece (cathode) is determined by a number of processes (Ref. 17), including the energy transferred from the arc column by convection, radiation and conduction; the phenomena that appear in the cathode region, such as thermoinic emission and the interaction of positive ions with the cathode surface; and the heat developed in the filler metal. This heat is transferred to the workpiece via the molten drops.

The above heat transport mechanisms determine the arc efficiency, which is defined as the fraction of total process energy delivered to the substrate and weld deposit (Refs. 17, 18): qa = (heat input to workpiece/total power input)*100%.

2) The weld deposit that develops during fusion welding of two dissimilar alloys will attain a chemical composition intermediate to the two alloys. The final deposit composition will depend on the individual compositions of the materials and the degree of mixing between the alloys. The degree of mixing is defined by the percentage dilution D (Ref. 18)

PctD = E ]1 VfmE s

14 Flaqm-~ ~ f m V f m "100(4 )

where Vfr n is the volume of deposited filler metal, Elm and E s represent the enthalpy change required to melt a given volume of filler metal and substrate, respectively, and the term qaqmVI represents the melting power delivered by the arc. Estimation of dilution with the approach presented by Dupont and Marder (Ref. 18) requires knowledge of the term thermal efficiency [arc efficiency (qa) * melting efficiency (qm)] of the welding process.

Melting efficiency (qm) is defined as the ratio of energy used for melting to that which is delivered to the workpiece (Ref. 18). Dupont and Marder (Ref. 18) presented a relation of the form

-175 11 m = O.5exp ~aVl5 /E~v (5)

where E is the enthalpy change due to melting (an average value between filler metal and substrate), qa is the nominal constant for a given process arc efficiency, qaVl is the net arc power deliv-

111111

11111 0

~ 1200

E

[3- . .

,,. electrode at time 11.5 s.

I ] I I I I I I I 0 0.5 1 1.5 2 2.6 3 3.5 4

Distance cm

-o- FEA Ke~= 35 WlmC -,,,,-

Chnstensen - ~ - G01d@

Fig. 2 - - Two-dimensional temperature distribution along the top of the workpiece perpendicular to the weld (electrode at time 11.5 s). Experimental bead-on-plate weld, V = 32.9 volts, I = 1170 amps, v = 0.005 m/s, qa = 0.95. Melt ing efficiency qm = 0.463 in the double ell ipsoid heat source for curve FEA using a coarse grid.

ered to the base metal (V is voltage and I is current), S is the welding speed, (z is the thermal diffusivity at 300 K and v is the kinematic viscosity at the melting point. In the present work, the values E = E s = 10.5 J mm -g, v = 0.84 mm2s -1, 0~ = 9.1 mm2s -1 were used.

3) The heat of the arc and the molten metal induces heat flow in all three dimensions in the workpiece. Conse- quently, complex metallurgical changes are produced in the fusion zone (FZ) and heat-affected zone (HAZ).

4) Boundary conditions must be employed to account for surface heat losses (natural convective heat transfer, quantic Stefan-Boltzman radiation and forced convection due to the flow of the shielding gas).

5) Thermal material constants must be considered as functions of temperature, composition and cooling rate (Ref. 19).

6) The phase transformation temperatures and the corresponding latent heats, along with the way in which the latent heats are released during the phase trans- formations, must be considered. If so-

called enthalpy formulation is used, the enthalpy values can directly be used if they are known. The enthalpy then includes all the other data except the thermal conductivity and the density (Ref. 19).

M o d e l Assumpt ions

To compare the results obtained by Christensen (Ref. 14), Krutz and Segerlind (Ref. 11), and Goldak, et al. (Ref. 3), the following assumptions were necessary:

1) The problem is reduced to find the two-dimensional transient temperature field at a section normal to the weld in- t e r f ace - Fig. 1.

2) All the boundaries except the top surface were assumed to be insulated.

3) On the top surface, the portion just under the arc was assumed to be insulated during the time the arc was playing upon the surface.

4) A combined convection and radiation boundary condition h = 24.1 "10 -4 E T T M (W/m2°C) was used on the remain-

n

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I (

i i ! ¢ I 4 ! ¢ i I i 1 I 1 I l

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| (

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L

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L ! i

| ¢ | ¢ L

I WELDING RESEARCH SUPPLEMENT I 123-s

A

l E O 0

1400

( ~ 1200

- ~ IOO0

1~=o E~=O

2OO

E l l i p s o i d a l D i s t r i b u t i o n

electrode at time 11.5 s.

~"qllL_~. . . . . . . . . . -,m

Dis tance cm - O - K l f f ~ 3 5 W / m C " ' ~ " " Kef f m17~; W / r n C

B

1500

O 12oo

eL) I-- 3oo

G a u s s i a n D is t r ibut ion

. . . . . . . . . . ~ electrode at time 11.5 s.

~k,,,~,

D i s t a n c e c m

- . o - K I f f = 3 5 W I m C - - a - - K I I R m 1 7 5 W / m C

Fig. 3 - - Postshock effect caused by effective thermal conductivity. A - - Ellipsoidal distribution; B - - Gaussian distribution. Note the difference in temperature distribution. Experimental conditions documented in Fig. 2.

der of the top surface. The value E = 0.9 was assumed as recommended for hot- rolled steel (Ref. 3).

5) The temperature-dependent material property functions (density and thermal conductivity) published by Mietti- nen, et al. (Ref. 19), were used for all calculations. Also from Ref. 19, thermal conductivity in the mushy (1477-1516°C) and liquid regions was calculated with the equation

Kef f -- (1 -fL)Ks+(1 +Amix)fLK L (6)

where fL = liquid fraction; fs = 1 - fL = solid fraction; K s -- thermal conductivity in solid state; K L = thermal conductivity in liquid state; Ami x = is a parameter de- scribing the effect of liquid convection (fluid motion) upon the thermal conductivity. If the constant Ami x is 0, there is no

1. In GMAW, the expression h = 13 Re 7/2 Pr 1/3 K~a/NPD reported by Tekriwal (Ref. 9) could lae easily incorporated.

increased heat transfer in the mushy or liquidus regions due to convection, i.e., the liquid phase is stagnant (Ref. 20). The value of Ami x depends on the mixing intensity. In this work, Ami x is assumed to be independent of fs or fL. For a continuous-steel casting process, for instance, a value of Ami x = 4 to 6 may be applied (Ref. 19).

In this work, to simulate heat transfer by stirring, a value Kef f = (1+4)'1"35 = 175 W/m°C was used. Moreover, for comparison purposes, a value Keff = (1+0)'1 *35 = 35 W/m°C also was used.

6) The temperature-dependent specific heat values reported by Brown and Song (Ref. 15) were used for the solid region.

7) In the mushy region, the equation

H Cp = Cli q ÷ TL _ Ts (7)

was used. Here, H = latent heat of fusion = 280 J/g, T L = liquidus temperature = 1516°C and T s = solidus temperature = 1477°C (Ref. 20). In the liquid region, a

value of Clig = 0.4 J/g°C was used. 8) No forced convection was as-

sumed, and the effect of gas diffusion in the weld pool was not considered)


Figure 2 shows a comparison of experimental and calculated temperature distribution along the top of the workpiece perpendicular to the weld interface for 11.5 s (x direction, Fig. 1). As expected, the FEA proposed gives a better "realistic" agreement with the Chris- tensen, et al. (Ref. 14), experimental data. The term "realistic" is used because, as was already demonstrated in (Ref. 1), to approximate a 3-D heat transfer analysis of a weld with a 2-D cross-sectional analysis introduces errors in the computed temperatures. In addition, the maximum temperature developed at different nodes at any given time is always higher in the 3-D analysis than the 2-D cross- sectional analysis; therefore, the 2-D FEA results satisfy the above observations.

Kamala and Goldak Ref. 1 believe the errors in the 2-D approximation can be eliminated by modifying the true power density distribution function. They consider that it was this type of modification that enabled the obtaining of "accurate" 2-D results in previous investigations (Refs. 3-12). As a consequence of that, the double ellipsoid model with appropriate parameters was proposed to correct for the lack of longitudinal heat flow in 2-D models. The accurate double ellipsoid results, to the best of the author's knowledge, are due to heat input excess to the workpiece, captured not only by nodes located below surface, but also by nodes assumed to represent the filler metal as in place at the start of the analysis. So, the magnitude of the real heat input is overestimated in the moment of considering the net arc power (rlaVI) delivered to the base metal in the energy input rate (Q), instead of considering melting power (TlaTlmVl) in all calculations.

Thermal efficiency was noted by Tsai and Eagar (Ref. 8). They observed the arc efficiency measured on the water-cooled anode was much higher than the "arc" (thermal) efficiency of normal welding measured in the presence of a molten metal pool. Pavelic, e ta l . (Ref. 10), used a value F = 0.3 in expression Q = FVl to give best agreement with the experimen- tally obtained temperature distributions. As noted, the above-mentioned works support the idea of this work to use thermal efficiency to quantify the energy made available by the arc. According to Tsai and Eagar (Ref. 7), arc (thermal) efficiency ranges from 30 to 70%.

124-s ] MAY 2000

Other explanations for Goldak's "accurate" results are not only the use of a fictitious Kef f = 120 W/re°C, but also the use of two heat input fractions ff = 0.6 and fr = 1.4, employed to provide the best correspondence between the measured and calculated thermal history results.

Figure 3 shows the postshock effect of effective thermal conductivity on the 2-D FEA-computed temperature distribution for the selected experimental conditions documented in Fig. 2. At times beyond the initial shock (e.g., 11.5 s), higher temperatures are observed in the ellipsoidal d istr ibut ion model. The reason is because the time the arc played upon the reference plane (load time) was 9 s for the ellipsoidal model and only 6 s for the disc Gaussian model.

The finite element solution was sensi- t ive to heat distr ibut ion and effective thermal conductivity. The significant differences in peak temperature values were attributed to the effective thermal conductivity.

It was observed from the fusion zone (FZ) and heat-affected zone (HAZ) that both models (ellipsoidal distribution and Gaussian distribution [Equation 2]) were able to approximate the size of weld area was into the Christensen's limits (Refs. 11-14).

The model results provided a straight- forward approach to understanding the effects of heat distribution and effective thermal conductivity. The double ell ip- soidal distribution produced lower peak temperatures but deeper weld penetra- tions. However, in both models, the FZ was completely formed at about 6 s. The double ell ipsoid model showed a poor sensitivity to simulate the suddenly appl ied electrode shock response. As noted, at 1.5 s the 723 and 1480°C isotherms do not appear yet.

Conclusions

1) The decoupled 2-D, cross-section, f ini te element, nonl inear model presented in this paper closely approximates actual welding conditions, but must be used cautiously because the results are sensitive to heat source distribution, heat source magnitude and effective thermal conductivity. However, features of structure-weld interactions can be investigated with this 2-D model.

2) Di lut ion can be accounted for in the heat transfer analysis through the melting efficiency term.

3) The double ellipsoid model is less sensitive than the Gaussian model to simulate substrate shock responses.

4) Since both models are very sensitive to distribution parameters (a,b,c in Equation 3 and c in Equation 2), to obtain

more accurate predictions and also to account the effect of arc length, an expression that combines the Gaussian function Equation 1 and the "disc" Gaussian distribution Equation 2 is needed. However, in absence of that, the Gaussian distribution Equation 2 is recommended to simulate the arc welding processes.

Acknowledgment

The author is grateful for f inancial support from Escuela Polit~cnica de Chimborazo, Riobamba, Ecuador.

References

1. Kamala, V., and Goldak, J. A. 1993. Error due to two dimensional approximation in heat transfer analysis of welds. Welding Journal 72(9): 440-s to 446-s.

2. Friedman, E. 1975. Thermomechanical analysis of the welding process using the finite element method. J. of Pressure Vessel Tech- nology, Trans. ASME, 97:206-213.

3. Goldak, J. A., Chakravarti, A. P., and Bibby, M. 1984. A new finite element model for welding heat sources. Metallurgical Trans- actions 15B: 299-305.

4. Fuerschbach, P. W., and Knorovsky, G. A. 1991. A study of melting efficiency in plasma arc and gas tungsten arc welding. Welding Journal 70(11 ): 287-s to 297-s.

5. Ushio, M., and Matsuda, F. 1982. Math- ematical modeling of heat transfer of welding arc (Part 1 ). Transactions of JWRI, pp. 7-15.

6. Oreper, G. M., Eagar, T. W., and Szekely, J. 1983. Convection in arc weld pools, welding Journal 62(11): 307-s to 312-s.

7. Tsai, N. S., and Eagar, T. W. 1983. Tem- perature fields produced by traveling distributed heat sources. Welding Journal 62: 346-s to 355-s.

8. Tsai, N. S., and Eagar, T. W. 1985. Dis- tribution of the heat and current fluxes in gas tungsten arcs. Metallurgical Transactions 16B: 841-846.

9. Tekriwal, P., and Mazumder, J. 1988. Fi- nite element analysis of three-dimensional transient heat transfer in GMA welding, welding Journal 67(5): 150-s to 156-s.

10. Pavelic, V., Tanbakuchi, R., Uyehara, O. A., and Myers, P. S. 1969. Experimental and computed temperature histories in gas tungsten arc welding of thin plates. Welding Jour- nal 48(6): 295-s to 305-s.

11. Krutz, G. W., and Segerlind, L. J. 1978. Finite element analysis of welded structures. Welding Journal 57(7): 211 -s to 216-s.

12. Goldak, J., Bibby, M., Moore, J., House, R., and Patel, B. 1986. Computer modeling of heat flows in welds. Metallurgical Transactions 17B: 587-600.

13. Goldak, J., Oddy, A., McDilI, M., and Chakravarti, A. 1986. Progress in computing residual stress and strain in welds. Interna- tional Conference on Trends in Welding Re- search, ASM International, Gatlinburg, Tenn.

14. Christensen, N., Davies, L. De. V., and Gjermundsen, K. 1965. British Welding Jour- nal 12: 54-75.

15. Brown, S. B., and Song, H. 1992. Im- plications of three-dimensional numerical simulations of welding of large structures.

Welding Journal 71 (2): 55-s to 62-s. 16. Omar, A. A., Lundin, C. D. 1976.

Pulsed plasma-pulsed GTA arc: a study of the process variables. Welding Journal 58(4): 408- s to 420-s.

17. Essers, W. G., and Walter, R. 1981. Heat transfer and penetration mechanisms with GMA and plasma-GMA welding, welding Journal 60(2): 37-s to 42-s.

18. DuPont, J. N., and Marder, A. R. 1996. Dilution in single pass arc welds. Metallurgi- cal and Materials Transactions 27B: 481-489.

19. Miettinen, J., and Louhenkilpi, S. 1994. Calculation of thermophysical properties of carbon and low alloyed steels for modeling of solidification processes. Metallurgical and Materials Transactions 25B: 909-916.

20. Lally, B., Biegler, L. T., and Henein, H. 1991. Optimization and continuous casting: part I. Problem formulation and solution strat- egy. Metallurgical Transactions 22 B: 641-648.

Appendix

Abbreviations

2-D two-dimensional 3-D three-dimensional CAD computer aided design CAM computer aided manufacture DC direct current EBW electron beam welding FEA finite element analysis FEM finite element model FZ fusion zone HAZ heat-affected zone Kef f effective thermal conductivity LBW laser beam welding MHD magnetohydrodynamics Q energy input rate q heat f lux per unit area

(or volume) per unit time

W E L D I N G RESEARCH SUPPLEMENT [ 125-s

Visualization of MaranwgeOni Convection in Simulated Id Pools

Marangoni convection resembling that in weld pools is revealed by flow visualization

BY C. LIMMANEEVICHITR AND S. KOU

ABSTRACT. A transparent pool of NaNO3 (10 mm in diameter) was heated with a defocused CO2 laser beam to simulate Marangoni convection in arc weld pools without a surface-active agent. The flow patterns were revealed clearly by flow visualization with a laser light-cut technique, the surface temperature profiles were measured immediately below the pool surface, and a device for measuring the beam diameter was developed. The observed Marangoni convection was expected to resemble that in welding because the Marangoni number was close to those in welding. Two counterrotating cells were observed in the meridian plane of the pool. The maximum velocity was at the pool surface, the outward surface flow was much faster than the inward return flow and the centers of the cells were near the pool edge. These characteristics suggest Marangoni convection dominates in the pool over gravity-induced convection. Increasing the beam power (from 0.5 to 5.4 W) and reducing the beam diameter (from 5.9 to 1.5 mm) both made Marangoni convection stronger. The latter, however, had a significantly greater effect; the surface flow was so much stronger as to make the return flow penetrate deeper into the pool. The results of physical simulation provided interesting insights for understanding the significant effect of Marangoni convection on the weld pool shape, as will be presented in a follow- up report.

Introduction

Marangoni convection, also called surface-tension-driven convection or thermocapillary convection, in the weld

C. LIMMANEEVlCHITR and S. KOU are graduate student and Professor, respectively, in the Department of Materials Science and Engi- neering, University of Wisconsin, Madison, Wis.

pool is of practical interest in welding. It can have a dramatic effect on the penetration depth of the resultant weld (Ref. 1). Marangoni convection in a weld pool without a surface-active agent is illustrated in Fig. 1. The surface-active agent of a liquid, e.g., S in liquid steel, is a material that can significantly reduce the surface tension of the liquid and even change its temperature dependence. As shown by the velocity profile, fluid flow near the pool surface is outward, with the maximum velocity v5 located at and tangent to the pool surface, where the sub- script, s, denotes the tangent direction. The outward-pointing shear stress at the pool surface, %s (-- -P-o~vs/c3n>0), is induced by the surface-tension gradients along the pool surface o3y/as (> 0), where n denotes the normal direction, I1 is the viscosity and 7 is the surface tension. These surface-tension gradients o]ylas(=o~T/o% x ay/aT) are induced both by the temperature gradients along the pool surface aT/as (<0) and the temperature dependence of the surface tension o-h,lc3T (<0). The fluid is pulled along the pool surface from the center (where temperature is high and the surface tension is low) to the edge (where temperature is low and the surface tension is high). Herein, the outward flow along the pool surface will be called the surface flow and the in-

KEY WORDS

Arc Welding Buoyancy Convection Flow Visualization Laser Beam Marangoni Convection Surface-Active Agent Weld Pool

ward flow in the interior of the pool will be called the return flow.

The presence of a very small amount of a surface-active agent can make the weld pool much deeper (Ref. 1). Ther- modynamics can show that in the presence of such an agent, the surface tension can, in fact, increase with increasing temperature, i.e., o~/o3T > 0 (Ref. 2). With the direction of flow reversed to favor convective heat transfer from the heat source to the pool bottom, a much deeper pool can be produced (Ref. 1). General information about Marangoni convection in the weld pool is available elsewhere (e.g., Refs. 3, 4).

Marangoni convection cannot be studied in arc welding because of the interference by the electromagnetic force in the weld pool and by the aerodynamic drag force of the arc. To avoid this problem, the arc can be substituted with a laser beam defocused to the size of the arc, as illustrated in Fig. 1. As in arc welding, melting is through heating from the top surface (the so-called conduction mode) and no vapor hole is produced in the weld pool by the laser beam (the so- called keyholing mode). The Marangoni convection induced by such a defocused laser beam should be similar to that induced by a welding arc.

Flow visualization in a weld pool is limited to the pool surface because the molten metal is opaque. In fact, even at the pool surface such observation can still be difficult because of the brightness of the arc. Ishizaki, et al. (Ref. 5), observed Marangoni convection in a thin slice of molten paraffin heated by a soldering iron in contact with its top surface. The flow pattern was two-dimensional rather than axisymmetrical and was not clearly revealed.

In the present investigation, Marangoni convection in weld pools without a surface-active agent is simulated using a transparent pool of NaNO~. Unlike paraffin, which is often a mixture

126-s I MAY 2000

Defocused CO 2 _ 8 y laser beam ~"~ --~s or

I ~v _ 8y aT Surface f low - , u an c3s c3T

, a , e me a,

Return j ~ ~ ~ /

Fig. I - - Marangoni convection in a weld pool induced by a laser beam defocused to the size of an arc.

of several organic compounds, the physical properties of NaNO3 are well documented. Furthermore, a CO2 laser beam rather than a soldering iron is used as the heat source to avoid interfering with flow in the pool and distorting the free surface and the flow pattern. To clearly reveal the flow pattern in the pool, a laser-light cut technique is used and optical distortions due to the lens effect of the pool are care- fully eliminated.

The objectives of the present study are to observe Marangoni convection in a simulated weld pool and to understand the effect of the power and diameter of the heat source on such flow. The results will be used to explain the effect of the heat source and the Prandtl number Pr on the shape of stationary weld pools. Due to space limitations, this will be dealt with separately in a subsequent paper. Oscillatory flow is beyond the scope of the present study.

Experimental Procedure

Materials

Sodium nitrate, NaNO3, was selected as the material for flow visualization because of the following reasons. First, NaNO3 has a transparent melt, a surface tension that significantly varies with temperature, a low melting point and well- documented physical properties, as shown in Table I (Reg. 6-10). Second, as will be described in the Results and Dis- cussion section of this paper, the Marangoni number Ma for the simulated NaNO3 weld pool to be studied here is close to those for steel and aluminum weld pools. According to the similarity law of hydrodynamics, similarity in Marangoni convection between two

CO 2 Lase.,. beam

Square glass be.. aker

Q

H e a t e r •

fluid systems can be expected if the Marangoni numbers are close to each other (Ref. 11). Third, NaNO3 has a transmission range of 0.35-3 ~m and is, therefore, opaque to a CO2 laser (10.6 ~m) just like a weld pool is opaque to the heat source. The purity of the NaNO3 used was above 99%.

Apparatus

Glass tube

Light sheet of He-Ne laser

,1

• NaNO 3 pool

NaNO 3 melt

0 0 0 0 0 0 0 • 0 0

@

Fig. 2 - - A transparent system for physical simulation of Marangoni convection in a weld pool, with the outer NaNOj melt keeping the pool molten and clear, and correcting optical distortions caused by the lens effect of the pool.

The apparatus for flow visualization, shown in Fig. 2, consisted of the following components. First, an essentially hemispherical pool of NaNO3 was held in a glass tube (10-mm ID). Second, a much larger NaNO3 melt was held in a square glass beaker (40 mm x 40 mm inside) to keep the pool from freezing and becoming opaque. Third, a CO2 laser beam was shone at the center of the pool

surface to induce Marangoni convection. Fourth, a He-Ne laser light sheet was passed through the meridian plane of the pool as an illuminator to reveal the flow pattern.

The glass containers were mounted on an x-y table to help align the center of the pool surface with the CO2 laser beam. The glass tube, 15 mm long and with a 0.5-mm wall, was lowered 8 mm into the NaNO3 melt. A thermocouple placed in the glass beaker near the bottom of its wall was hooked up to a temperature controller set at 330°C. In the absence of a CO2 laser beam, this gave a temperature of 323.4°C at the bottom of the outer surface of the glass tube.

Table 1 - - Physical Properties of NaNO s Melt (Re@. 6-10)

Properties

Meltiing point, Tm, °C Decomposition temperature, Td, °C Autoignition point, Ta, °C Heat of fusion, AH, J/g Temperature coefficient of surface tension, ay/aT, dyne/(cm °C) Surface tension, "y, dyne/cm Dynamic viscosity, i~, g/(cm s) Density, p, g/cm 3 Specific heat, Cp, J/(g °C) o Thermal conductivity, k, W/(cm C) Thermal expansion coefficient, [3, °C-~ Thermal diffusivity, ~x = k/(p Cp), cm2/s Prandtl number, Pr = Cp i~/k Refractive index, n Emissivity, Transmission range, k, cm

N a N O 3

306.8 380 538 182 -0.056 119.96 at Tm 0.0302 at T m 1.904 at Tm 1.71 atTr, 5.65 X 10 _3 atTm 6.6 X 10 -4 1.74 X 10 -~ atT m 9.12 atT m 1.46 0.3 0.35 x 1 0 4 - 3 x 10 4

WELDING RESEARCH SUPPLEMENT [ 127-s

A Black anodized aluminum -3

/

50 I~m = ~-

/ gap

Aluminurr base _

Insulatien ~ ~ Insulation (Wood) ~ [ (.Wood)

Moving Direction

Black anodized aluminum

pies

l Digital I ~ micrometer stage

B 7

E 6 E , - ' 5 (9 o 4 E .__. 3 "10 E 2 (o • 1 nn

0 k

4 6

I I I I i

• A t 4 0 . 7 3 c m [ • At 38 .73 cm

2 8 10 12 14

Collimator stop

Fig. 3 - - Measurement of the diameter of a C02 laser beam: A - - The device developed in the present study; B - - results obtained at two different distances below the beam bender.

Fig. 4 - - Flow pattern induced by a CO 2 laser beam of 2.5 W and 3.2 mm diameter.

While flow visualization in water is easy to do, flow visualization in a melt at an elevated temperature can be tricky. The apparatus is unique in that it was transparent and free from optical distortions, as described in the following:

I) The heater keeping the NaNO~ pool from freezing was transparent. This heater was the NaNO3 melt surrounding the pool and was itself heated by a Nichrome-wire heater positioned below the laser light sheet to avoid blocking the view. Both the tube and the beaker were transparent Pyrex glass.

2) The heater corrected the severe optical distortions in the observed flow patterns by eliminating the lens effect of NaNO3 (refractive index n --- 1.46). The NaNO3 pool was, in fact, an optical lens. To correct this lens effect, the glass beaker was made square rather than round. Furthermore, the difference between the refractive index of the NaNO3 melt and that of Pyrex glass (n = 1.47) is too small to cause any additional optical distortions in the observed flow patterns. The NaNO3 melt was much larger in volume than the pool in order to make the temperature around the pool stable and uniform.

Experiments were also carried out using a different heat source - - a Nichrome wire of 0.76 mm diameter heated by passing an electric current through it. The CO2 laser alone was replaced by the wire heater; the rest of the system, including the transparent heater surrounding the pool, remained un- changed. The wire was bent into the shape of a sharp V, and the bottom end of the V was lowered to touch the center of the pool surface. A 0.25-mm-diameter K-type thermocouple was spot welded to the bottom of the V from the side to measure its temperature.

Beam-Diameter Measurement

The CO2 laser had a wavelength of 10.59 llm, power stability of + 5%, beam quality of M2 < 1.2 and beam mode of TEM00 and 90% purity (better than 90% Gaussian), where M is the magnification factor. The raw beam diameter was 4.4 mm, and the beam divergence was 3.2 mR. A beam bender deflected the horizontal laser beam downward. A two-lens beam collimator with 15 stops available for varying the beam diameter was mounted under the beam bender. The beam power was measured with a power meter having a 0.1-W resolution.

To measure the beam diameter, the device shown in Fig. 3A was prepared. To increase absorption of the beam power, a black anodized aluminum sheet, 58 mm long x 20 mm wide x 2 mm thick, was

128-s I MAY 2000

used to receive the laser beam. Two K- type thermocouples were mounted 3 mm from each other at the center of the black anodized aluminum sheet from its bottom. This aluminum sheet was bonded to two wood blocks, which served as a thermal insulator and which themselves were bonded to an aluminum base. The anodized aluminum sheet was then cut in the middle with a precision wire saw with a 50-p,m-diameter tungsten wire. A smaller wire, e.g., 10 gm diameter, can be used if smaller beams are to be measured. The whole assembly was then mounted on a digital micrometer stage that could be reset to zero at any position.

The device was positioned so the top surface of the anodized aluminum was at the height where the beam diameter was to be measured, i.e., at the level where the center of the pool surface was expected in subsequent flow visualization experiments. This level was 38.7 cm below the beam bender. With a 3-W CO2 laser beam shining on the left half of the anodized aluminum, the micrometer stage was moved to the left until the right thermocouple sensed a quick, clear temperature rise. The micrometer was reset to zero at this position and the system was cooled to room temperature with an air gun. The micrometer stage was then moved farther to the left until the laser beam could shine only on the right half of the anodized aluminum. With the laser beam shining on the right half of the anodized aluminum, the micrometer stage was moved to the right until the left thermocouple sensed a similar temperature rise. This position reading of the micrometer stage was taken as the beam diameter. The micrometer stage was then turned 90 deg and the beam diameter was measured in the new direction following the same procedure. The average of the two measurements was taken as the beam diameter. This procedure was repeated for all stops of the beam collimator. The beam diameter was also measured at 40.7 cm below the beam bender.

Flow Visualization

A laser light-cut technique for flow visualization was used. The laser light sheet was produced with the help of a 20- mW He-Ne laser and optical lenses. Alu- minum particles 20 I.tm in diameter were used as a tracer. The density of aluminum (2.7 g cm-3) is greater than that of the NaNO3 melt (1.9 g cm-3). From Stokes's law (Ref. 4), however, the settling velocity is much slower than Marangoni convection in view of the small particle diameter. In fact, aluminum particles are often used for flow visualization in water

(Ref. 12), which is even lighter than NaNO3 . A certain amount of aluminum particles gradually settled to the pool bottom over extended peri- ods of time. Pho- tographs of the flow patterns were taken at the exposure time of 0.625 s, with the reflex mirror of the camera locked to reduce vibration.

Surface Temperature Measurement

The surface temperature profiles near the pool surface were measured with a K-type thermocouple. It was prepared from 0.05-mm (0.002- in.) diameter wires with an exposed bead 0.125 mm (0.005 in.) in diameter. To minimize interference with flow, the thermocouple was bent into a J shape to conform to the pool wall and axis. With the help of a digital micrometer x-y stage and a magni- fying lens, the tip of the thermocouple was positioned at 0.125 mm below the pool surface.


Diameter of Heat Source

In numerical simulation of heat and fluid flow in the weld pool, the power-density distribution of the heat source is often assumed Gaussian and the effective diameter of the heat source is often defined as the diameter that covers 95% of the total power of the heat source (Ref. 13). The simple device developed in the present study measures an effective beam diameter within which heating can be de-

Fig. 5 - - Flow patterns induced by a COt laser beam o f 5.9 mm diameter at the fol lowing power levels: A - - 0.5 W; B - - 2.5 W; C - - 5.4 W. Fluid f low becomes faster but shallower as the power is in-

creased.

tected with a thermocouple. It does not specify which kind of definition the effective diameter is based on. The precise definition of the effective beam diameter, however, is not critical because the focus here is to demonstrate the effect of the beam diameter on Marangoni convection, and the conclusions drawn will not


from edge

Lower i Higher beam power i beam power[ pool

slower, deeper!faster, shallower ~ edge

N / ~ / ~loser / ,oe, o / z " ~ . cOntainer

~ wall

Fig. 6 - - Effect o f the power o f the laser beam on the f low pattern.

be affected by how precisely the beam diameter is defined. Both the actual power density distribution of the heat source and its effective diameter, however, can be determined if desired. This can be done by determining the amount of power absorbed by each of the two anodized aluminum sheets while they are being traversed under the heat source at a constant slow speed (Ref. 14). The power density distribution can be obtained with the help of Abel transformation. This, however, is no trivial task. Commercial instruments might be available but rather expensive.

Figure 38 shows the results of beam diameter measurements at 38.7 and 40.7 cm below the beam bender. As shown, with the center of the pool surface positioned at 38.7 cm below the beam bender, the beam diameter can be varied from about 1.3 to 5.9 ram, which is close to the diameter of a gas tungsten arc.

Three beam diameters were used in the present study: 1.5, 3.2 and 5.9 mm. The 5.9-mm beam diameter seems a rea- sonable upper boundary considering the already small clearance of about 2 mm between the beam and the inner wall of the 10-mm-ID glass tube holding the pool.

Flow Pattern

Figure 4 shows the flow pattern induced by a CO2 laser beam of 2.5 W power and 3.2 mm diameter. It is worth noting the pool surface in conduction- mode laser beam welding can be concave due to Marangoni convection and surface tension (Ref. 15), and, in fact, this has been shown to be the case experi- mentally (Ref. 16) and by computer simulation (Ref. 17). The concave pool surface shown in Fig. 4, however, is just a

coincidence; the melt wets the container wall and forms a meniscus to make the pool surface concave.

The arrows above the pool surface indicate the directions of flow along the pool surface. The flow lines above the pool surface are not real but are only the image of the flow lines inside the pool. The concave free surface acts as a mirror and shows the flow lines that are inside the pool.

Fluid flow is steady, axisymmet- ric and essentially unicellular, though it is not clear if there are much weaker secondary cells near the pool bottom. In the meridian plane of the pool, however, the flow pattern appears as a clockwise cell on the right and a counter- clockwise cell on the left. In other words, the melt at the center of the pool surface flows outward along the pool surface, turns downward at the pool edge to fall along the pool wall and then returns to the center of the pool surface.

The flow lines are most closely spaced near the pool surface and become more widely separated below the pool surface

Fig. 7 - - Flow patterns induced by a 2.5-W COt laser beam at the fog lowing diameters: A - - 5.9 ram; B - - 3.2 ram; C - - 1.5 ram. Fluid f low becomes faster and deeper as the beam diameter is reduced.

and in the bulk pool. The top of the right half of the pool in Fig. 4 is particularly clear in showing that the flow lines con- verge near the pool surface. There is little flow in the area near the bottom of the pool. The centers of the cells are near (0.9 mm below) the pool surface and close to (1.4 mm from) the wall. Therefore, it appears the maximum velocity is atthe pool surface (as illustrated in Fig. 1), the sur-

130-s [ MAY 2000

4

Larger i Smal ler I Ibeam diameterl i l ~eam diameter I _pool

h ~ r ~ }lower, shallower i faster, deeper . , ~ edge

Fig. 8 - - Effect of the diameter of the laser beam on the flow pattern.

Fig. 9 - - Flow pattern induced by a wire heater touching the center of the pool surface, the heater being 48.6°C higher in temperature than the pool edge.

face flow is much faster than the return flow and the centers of the cells are close to the pool edge. The videotape recorded during flow visualization (Ref. 18) confirms these characteristics of Marangoni convection. Therefore, it is clear Marangoni convection dominates over bouyancy convection.

Effect of Heat Source Power

Three levels of the beam power are used in the present study: 0.5, 2.5 and 5.4 W. Further increase in power tends to cause oscillatory flow, especially at small beam diameters.

Figure 5 shows the effect of the beam power on fluid flow at the beam diameter of 5.9 mm. At 0.5 W fluid flow is slow, unsteady and lacking axisymmetry, as shown in Fig. 5A. Since the surface flow is slow, the return flow appears to have plenty of time to fall to near the pool bottom before rising to the pool surface. Buoyancy convection is expected to play a significant role in view of the weak Marangoni convection.

At 2.5 W, fluid flow is significantly faster, steady and essentially axisymmetrical, and the centers of the cells move closer to the edge of the pool surface, as shown in Fig. 5B. However, the cells are now shallow penetrating and, in fact, look more triangular than round. Since the surface flow is faster now, the return flow also has to be faster to satisfy the continuity requirement. Instead of falling near the pool bottom and then rising to the pool surface, which takes time, the return flow appears to take a shortcut back to the pool surface.

At 5.4 W, fluid flow is even faster. The cells are even more shallow penetrating and triangular, and the centers of the cells move even closer to the edge of the pool

surface, as shown in Fig. 5C. Similar experiments conducted at the 3.2- and 1.5- mm beam diameters show a similar effect of the beam power.

The effect of increasing the beam power is summarized in Fig. 6. As the beam power is raised from 0.5 to 5.4 W at the constant beam diameter of 5.9 mm, flow becomes significantly faster and the centers of the cells move closer to the pool edge. The faster surface flow requires a faster return flow to satisfy continuity, and the return flow takes a shortcut back to the pool surface instead of reaching the pool bottom. This results in shallow-penetrating, triangular cells.

In a real weld pool, the pool diameter is not fixed but allowed to increase as the power is increased. The effect of this will be discussed later in this paper.

The authors are not aware of any numerical simulations that have predicted the effect of the beam power observed here. However, Kamotani, et al. (Ref. 19), have conducted numerical simulation of Marangoni convection in a liquid that is held in a cylindrical container with a flat bottom and that is heated by a laser at the center of the free surface. The calculated streamlines show cells similar to those observed in the present study. Further- more, as Marangoni convection becomes stronger, the cells become shallower and more triangular, and the centers of the cells move closer to the pool edge.

Effect of Heat Source Diameter

Figure 7 shows the effect of the beam diameter on fluid flow at the power level of 2.5 W. Figure 7A, which shows the flow pattern induced by a 5.9-mm beam, is identical to Fig. 5B. As already mentioned, the cells are shallow and triangular.

With the beam diameter reduced to 3.2 mm, Marangoni convection becomes significantly faster and, as shown in Fig. 7B, the centers of the cells move closer to the pool edge. The surface flow now accelerates more sharply toward the pool edge. This gives the return flow more momentum to penetrate deeper into the pool, even though this means the return flow has to travel a longer distance and at a higher velocity back to the pool surface.

With the beam diameter further reduced to 1.5 mm, the surface flow accelerates even more sharply. As shown in Fig. 7C, the return flow now penetrates even deeper into the pool. Having to return to the pool surface with a much higher velocity, the return flow turns abruptly near the pool surface. Similar experiments conducted at 0.5 and 5.4 W show a similar effect of the beam diameter.

The effect of reducing the beam diameter is summarized in Fig. 8. As the beam diameter is reduced from 5.9 to 1.5 mm at the constant power of 2.5 W, flow becomes much faster and the centers of the cells move closer to the pool edge. The return flow gains extra momentum to penetrate deeper into the pool.

Again, in a real weld pool, the pool diameter is not fixed but allowed to increase as the power is increased. The effect of this will also be discussed later in this paper.

The authors are not aware of any numerical simulations that have predicted the effect of the beam diameter observed here, though it is likely such simulations may have been done. Heater Touching Pool Surface

The advantage of the wire heater is that the temperature difference across the pool surface, which is the driving force

WELDING RESEARCH SUPPLEMENT[ 131-s

I 4 1 0 / ' : i ! : = i , q i i ' i i ; : I

I - I - ~ ....... ~ - ~ - ~ - " I 4 0 0 1 ~ ' . ', ! I I • (a)5.9mm, 5.4W

oO 390 "l ! ' : : I o (b) 5.9 mm, 2.5 W -[ I " (c) 5.9 mm, 0.5 W

380 [ i ; , [ v (d) 1.5 mm, 2.5 W 370 N - ~ i '. ! ;- - ; " i 15 2 5 W ~ ~ - ~ i a ) i I - - - - (d') . mm, .

~. 360 4 ; . . . " ~ : - ~ : ~ ~ ~'..;-- - ~ : • ; ~- ~ 4--J~-~- 'J #H'i-~.. ', ~ , " ! ' ~ 1 , , , , i , ' I ~ I ;

E ~ ~'/'-~,,. , ' ! , , ~ I 11~<~ . . . . . . . : I i

3 5 0 - r ' ~ i : C l-,~!-"~, ; ' ; ; i F

8 340 : ! ~ i. : :

(~ 330

320

/ ' i .~ I I , 300 !1.5m1 ; '

0 - ' 1 2 3 4

Radia l d istance, m m

Fig. 10 -- Temperature profiles along but slightly below the pool surface at various diameters and power levels of the laser beam. The broken curve shows the projected surface temperature profile for 1.5-mm diameter and 2.5-W power. Dotted lines are tangents showing the maximum radial temperature gradients.

for Marangoni convection, can be easily found. Of course, the disadvantage is that, unlike a laser beam, it touches the pool surface, though much less than a soldering iron does.

Figure 9 shows the flow pattern induced by the V-shaped wire heater touching the center of the pool surface. The temperature at the center of the pool surface, as indicated by the thermocouple spot welded to the tip of the heater, was 373.7°C, and the temperature at the pool edge was 325.1°C. As such, the surface temperature was 48.6°C higher at the center than at the pool edge. The flow pattern is closest to that induced by a 2.5-W beam of 1.5 mm diameter - - Fig. 7C. The differences, however, are that a hump is formed at the center of the pool surface by the meniscus at the wi re heater and the centers of the cells are farther away from the pool edge. More details on the flow patterns induced by the wire heater are available elsewhere (Ref. 20).

Surface Temperature Profiles

The temperature profile along the pool surface is most helpful for understanding Marangoni convection in the pool but difficult to measure with a thermocouple. An alternative is to use an infrared imager, e.g., that used by Kamotani, et al. (Ref. 21), to study

Marangoni convection in a silicone oil held in a cylindrical container with a flat bottom and heated by a vertical wire along the axis. In the case of silicone oil, the infrared imager detected radiation emitted by a 0.2-mm-thick surface layer. No data are available to verify this is also true in the case of NaNO3. Radiation from the interior of the pool can cause significant errors in measuring the pool surface temperature. Another difficulty is the laser beam is in the way, making overhead imaging over a relatively small NaNO3 pool difficult.

The solid curves in Fig. 10 show the temperature profiles measured along the pool surface - - with the tip of the thermocouple positioned at 0.125 mm below the pool surface. All curves are drawn with an essentially zero slope at the center of the pool surface in view of the thermal boundary condition 0Thgr = 0 at the axis of symmetry r = 0. The maximum radial temperature gradient (-'gT/0r)max at the pool surface is indicated with a tangent (dotted line) to each curve of the temperature profile.

Curves a through c are the temperature profiles induced by a 5.9-mm-diameter beam. As shown, as the beam power is increased from 0.5 to 5.4 W, the temperature near the center of the pool surface rises more significantly than that near the edge. As such, the temperature

difference AT between the center and the edge of the pool increases with increasing beam power, and this explains why convection becomes faster when the beam power is increased - - Fig. 5. The maximum radial temperature gradient (-(gT/0r) .... which occurs around the edge of the laser beam, increases from about 4 to 11 and 21 °C/mm as the beam power increases from 0.5 to 2.5 and 5.4 W, respectively.

Curves b and d show the temperature profiles induced by a beam power of 2.5 W. As the beam diameter is reduced from 5.9 to 1.5 mm, three things change significantly. First, (~gT/ar)max increases from about 11 to 50°C/mm. Second, the radial position of (-aT/0r)r~ax is no longer about 3 mm from the center of the pool surface, but much closer at about 0.3 ram. Third, the power density qz rises sharply by a factor of (5.9/1.5) 2 or 15.5.

From Fourier's law of conduction, at the pool surface

k aT qz = - - - (1) az

where qz is the heat flux due to the laser beam, k the thermal conductivity of the melt and z the distance along the axis of the pool. As an approximation,

Q = k (AT)a (2) 2rR ~ 6T

where Q is the beam power, R, the beam radius, (5 T the thickness of the thermal boundary layer at the free surface caused by laser heating and (AT)~ the temperature drop across 6-i-. In view of the very low k of NaNO3 (Table 1 ), the temperature gradient o~T/az at the pool surface under the laser beam is expected to be high. As such, the actual surface temperature profiles can be expected to be higher than the measured ones, especially the one for a 1.5-mm beam diameter.

For the case of 2.5-W power and 1.5- mm beam diameter, the temperature measured at 0.125 mm below the center of the pool surface is 343°C, according to Curve d of Fig. 10. The true surface temperature should be between 343°C and the decomposition temperature of 380°C because decomposition was not observed. As such, the true temperature at the center of the pool surface is not expected to be more than about 370°C. This gives a (AT)a of 27°C. From k = 5.65 x 10-~ W/cm-'°C -] and Equation 2, ~ = 0.011 mm (or 11 ~m), which is about one-tenth of the distance between the thermocouple and the free surface (0.125 mm). This very small 6r is a consequence of the very low k plus the impingement of the free surface by the cooler return flow from below. It is interesting to note 370°C

132-s I MAY 2000

happens to be close to the temperature 373.7°C of the heater touching the center of the pool surface - - Fig. 9.

The projected surface temperature profile is shown in Fig. 10 by Curve d'. The high AT across the pool surface and the high (-o~T/o3r)max explain why Marangoni convection becomes much faster and deeper as the beam diameter is reduced from 5.9 to 1.5 mm - - Fig. 7. This surface temperature profile is similar to those calculated by Kamotani, et al. (Ref. 19), for laser-beam-induced Marangoni convection in silicone oil held in a cylindrical container. There, the surface temperature decreases with increasing radius, but not at a constant rate across the free surface. The surface temperature drops sharply near the edge of the laser beam but beyond this point it does not decrease much at all, especially when Marangoni convection is significant (Ma close to and greater than 1 x 104). In the presence of significant Marangoni convection, the calculated temperature field in the pool shows a very thin thermal boundary layer at the pool surface under the laser beam. o3T/i~z is very high within the boundary layer but much lower beyond it.

For the case of 5.9-mm beam diameter, q~ is much lower and the measured surface temperature profiles, Curves a through c, are more accurate. If the same S T of 0.011 mm is used, (AT)a is less than 4, 2 and 0.5°C at 5.4, 2.5 and 0.5 W, respectively.

Marangoni Number and Marangoni Convection

The Marangoni number, which has been used widely as a measure for the ex- tent of Marangoni convection, is a di- mensionless number defined as

Ma ~T (AT)L = (3)

where o37/o3T is the temperature coefficient of surface tension, AT the temperature difference between the center and edge of the pool surface, L the characteristic length, I.t the dynamic viscosity and c~ the thermal diffusivity.

From Curve d' in Fig. 10, AT = 55°C for a 2.5-W laser beam of 1.5-mm diameter. The characteristic length L can be taken as the pool radius 5 mm. From Equation 3 and the physical properties given in Table 1, the Marangoni number Ma = 2.93 x 104 .

From computer simulation of heat and fluid flow in stationary weld pools of steel (Refs. 22-24), L is about 4 mm (from 3 to 5 mm) and AT is about 750°C (from 500 to 1000°C). Also, lLt is about 5 x 10 -2 g

cm-ls -1 and (x is about 5 x 10 _2 cm 2 s -1 . For a steel with a negligible amount of sulfur, o37/o3T can be taken as -0.3 dyne cm-l°C -1 (Ref. 24). From Equation 3, Ma = 3.60 x 104 , which is of the same order of magnitude as Ma = 2.93 x 104 for the simulated weld pool.

Similarly, Tsai, et al. (Ref. 17), calculated heat and fluid flow in a stationary aluminum weld pool produced by a defocused laser beam. There, L = 3 mm, AT = 850°C and aT/aT = -0.35 dyne cm-l°C -1. In addition, p = 1 x 10 -2 g cm -1 s -1 and (x = 3.75 x 10 -1 cm 2 s -1. From Equation 3, Ma = 2.38 x 104. This, again, is of the same order of magnitude as Ma = 2.93 x 104 for the simulated weld pool of NaNO 3.

Heat and fluid flow in a stationary aluminum weld pool produced by a gas tungsten arc has been calculated by Kou, et al. (Ref. 13). There, L = 3 mm and AT -- 1050°C. Based on the same physical properties mentioned before and Equa- tion 3, Ma = 2.94 x 104, which again is of the same order of magnitude as Ma = 2.93 x 104 for the simulated weld pool of NaNO 3.

As such, the Marangoni convection observed in the simulated weld pool can be expected to be similar to that in stationary weld pools produced by a defocused laser beam or an arc. According to the similarity law of hydrodynamics (Ref. 11), similarity in Marangoni convection between two different fluid systems of similar shapes can be expected if the Marangoni numbers are close to each other. The flow pattern in Fig. 4 is consistent with the calculated flow patterns (Refs. 13, 17, 22-24) in the following ways. First, the centers of the cells are near the pool edge; second, the maximum velocity is at the pool surface; and third, the surface flow is much faster than the return flow.

In the present physical simulation, the laser beam is used primarily to induce thermocapillary convection. In actual welding, however, the heat source has to melt a small portion of the workpiece to produce a weld pool. As such, the heat input required is much greater in welding than in the physical simulation. The high welding heat input causes a AT that is much higher than that in the physical simulation, as already shown. However, this difference is very much absorbed by the much higher c~ of a metal workpiece such as steel or aluminum, as suggested by the definition of Ma according to

Fig. 11 - - Flow pattern in a 4-mm-diameter pool induced by a 2-W laser beam of 1.5 mm diameter.

Equation 3. This is why Ma for the simulated weld pool can still be close to Ma for a weld pool of steel or aluminum. When welding solid NaNO 3, a higher heat input is required; for example, 10 W produces a pool of about 8-mm diameter (as opposed to 2.5 W for inducing Marangoni convection in the simulated pool). The corresponding AT will be higher (say, by one-third) and L lower (by one-fifth), and so Ma for such a NaNO 3 weld pool can still have more or less the same order of magnitude as Ma for the simulated pool.

Effect of Tube Wall

As mentioned previously, in a real weld the pool diameter is not fixed but allowed to change depending on the welding condition. Curves a through c in Fig. 10 indicate the temperature at the pool edge increases by about 12°C when the power of the 5.9-mm-diameter beam increases from 0.5 to 5.4 W, suggesting the pool diameter would increase if it were allowed to. From Equation 3, increasing the pool radius L increases Ma and hence Marangoni convection. Therefore, the effect of increasing the beam power on Marangoni convection is likely to be reduced by the presence of the glass tube.

Curves b and d in Fig. 10, on the other hand, show that decreasing the beam diameter of a 2.5-W laser beam from 5.9 to 1.5 mm hardly changes the temperature at the pool edge at all. As such, reducing the beam diameter is not expected to change the pool radius L significantly, and its effect on Marangoni convection is not affected significantly by the presence of the tube wall. Recent experiments have shown that reducing the beam diameter affects the shape of a NaNO 3 weld pool significantly but not the pool diameter (Ref. 26).


Bond Number and Buoyancy Convection

Because of heating by the laser beam, the pool surface is warmer at the center than at the edge. As such, buoyancy convection causes the melt to rise along the pool axis and fall along the wall just like Marangoni convection. It is, therefore, desirable to check if the convection observed in the simulated weld pool is dominated by Marangoni or buoyancy convection.

The dynamic Bond number is a di- mensionless number defined as follows:

Bo = i~pgL2 (4)

~T where ]3 is the thermal expansion coefficient of the melt, p the density of the melt, g the gravitational acceleration 980 cm s-2, L the characteristic length taken as the radius of the pool and o3y/o~T the temperature coefficient of the surface tension. The dynamic Bond number Bo is often used as a qualitative indication of the strength of buoyancy convection relative to that of Marangoni convection.

From computer simulation of heat and fluid flow in stationary weld pools of steel (Reg. 22-24), L is about 4 mm, l~ is 1 x 10-4°C -1, p is 7.2 g cm -3. As already mentioned, for a steel with a negligible amount of sulfur, e3y/o~T can be taken as -0.3 dyne cm -1 °C-1 (Ref. 24). From Equa- tion 4, Bo = 0.38. From computer simulation of heat and fluid flow in stationary weld pools of aluminum (Refs. 13, 17), L is about 3 mm, ~ is 1 x 10--4°C -1, p is 2.7 g cm -3 and o~y/o~T is -0.35 dyne cm-l°C -1 . From Equation 4, Bo = 0.068. Therefore, in welding, Marangoni convection dominates over buoyancy convection.

For a 10-mm-diameter NaNO 3 pool, the thermal expansion coefficient of the melt [3 is 6.6 x 10-4°C -1, the density of the melt p is 1.90 g cm -3, the gravitational acceleration g is 980 cm s -2, the characteristic length L is taken as the radius of the pool 0.5 cm and the temperature coefficient of surface tension o3y/o3T is -0.056 dyne cm-l°C -1. From these values and Equation 4, Bo = 5.5 for a 10-mm-diameter pool. This is believed to be an overestimate of the importance of buoyancy convection because the characteristics of the flow in the pool (Fig. 4) suggest predominance of Marangoni convection, as described previously.

To reduce the Bond number, experiments with a smaller pool of 4 mm diameter were attempted. From Equation 4, the dynamic Bond number Bo for a 4- ram-diameter pool is 0.88. This is more than six times smaller than that of 5.5 for a 10-mm-diameter pool. In other words, the strength of Marangoni convection rel-

ative to that of buoyancy convection is raised more than six times.

Figure 11 shows the flow pattern in a 4-mm pool induced by a 2-W beam of 1.5 mm diameter. Despite a number of problems associated with a small 4-mm- diameter pool, which will be described later, the flow pattern is very similar to that shown in Fig. 4 for a 10-mm pool. First, the surface flow is much faster than the return flow and there is little flow near the pool bottom. Second, the flow lines are much more closely spaced near the pool surface than in the bulk pool. Third, the centers of the cells are close to the edge of the pool surface. If flow in the 10- mm pool was not also dominated by Marangoni convection, the two flow patterns would not be very similar.

The problems encountered in the experiments with a 4-ram pool were as follows. First, the 4-mm pool was too small to measure the temperature distribution along the pool surface, vary the beam diameter over a significant range and keep the aluminum tracer particles from ag- glomerating. As shown in Fig. 11, the ag- glomerated tracer particles cause some flow lines to look more like ribbons. In fact, there would have been even more ribbons had the exposure time not been reduced from 0.625 to 0.1 s. Second, a higher magnification is required for pho- tographing a 4-mm pool. Even with the reflex mirror in the camera already locked up, there can still be slight camera vibration to make the flow lines appear wavy in the resultant photograph, as evident in Fig. 11. Third, the radius of curvature of the pool surface was rather small in a 4-mm tube, making the pool surface highly concave, as also evident in Fig. 11.

In view of these difficulties it is almost impossible to conduct experiments with a 2-mm-diameter pool, even though the very small dynamic Bond number of 0.22 is a definite advantage. Reduced gravity, such as that provided by a drop tower or a parabolic-flight aircraft, is therefore ideal for studying Marangoni convection in a simulated weld pool. It allows the use of a pool large enough (e.g., 10 mm diameter) for conducting experiments while suppressing buoyancy convection at the same time.

Conclusions

• Marangoni convection in the absence of a surface-active agent has been observed, clearly and without optical distortions, in a simulated transparent weld pool of NaNO 3 subjected to a defocused CO 2 laser beam.

• The Marangoni number for the simulated weld pool is close to those for

welding. From the similarity law of hydrodynamics, the Marangoni convection observed in the simulated weld pool can be expected to resemble that in welding.

• Two counterrotating cells appear in the meridian plane of the pool, the maximum velocity is at the pool surface, the outward surface flow is much faster than the inward return flow, and the centers of the cells are near the pool edge. These are characteristics of Marangoni convection, and they suggest Marangoni convection dominates in the pool over gravity-induced bouyancy convection.

• Increasing the beam power and reducing the beam diameter both make Marangoni convection stronger and both move the centers of the cells closer to the pool edge, but the effect of the latter is significantly greater.

• Within the range of the experimental conditions investigated, increasing the beam power tends to reduce the depth of convection, while reducing the beam diameter tends to increase it because of the increased momentum of the returning flow.

• The use of a heater in contact with the pool surface can cause both the pool surface and the flow pattern to distort significantly.

Acknowledgments

This work was supported by NASA under Grant No. NAG8-1459.

References

1. Heiple, C. R., and Roper, J. R. 1982. Mechanism for minor element effect on GTA fusion zone geometry. Welding Journal 61 (4): 97-s to 102-s.

2. Sahoo, R, DebRoy, T., and McNallan, M. J. 1988. Surface tension of binary metal- surface active solute systems under conditions relevant to welding metallurgy. Metallurgical Transactions 19B(3): 483-491.

3. Kou, S. 1987. Welding Metallurgy. New York, N.Y., John Wiley and Sons, pp. 91-103.

4. Kou, S. 1996. Transport Phenomena and Materials Processing. New York, N.Y., John Wiley and Sons, pp. 499-515, 44-48.

5. Ishizaki, K., Araki, N., and Murai, H. 1965. Penetration in arc welding and convection in molten metal. Journal of Japan Welding Society 34(2): 146-153 (in Japanese).

6. White, L. R., and Davis, H. T. 1967. Thermal conductivity of molten alkali nitrates. Journal of Chemical Physics 47(12): 5433-5439.

7. Janz, G. J. 1972. Journal of Physical Chemistry, Reference Data: 1 (3): 583-704.

8. Preisser, F., Schwabe, D., and Schar- mann, A. 1983. Steady and oscillatory thermocapillary convection in liquid columns with free cylindrical surface. Journal of Fluid Mechanics 126: 545-567.

9. Atomergic Chemetals Corp. 1993. Datasheet. Farmingdale, N.Y.

10. Alfa AESAR. 1999. Material safety data

134-s I MAY 2000

sheet for NaNO 3. Ward Hill, Mass. 11. Schwabe, D., Scharmann, A., Preisser,

F., and Oeder, R. 1978. Experiments on surface tension driven flow in floating zone melting. Journal of Crystal Growth 43:305-312.

12. Rouse, H. 1978. Elementary Mechan- ics of Fluids. New York, N.Y., Dover Publica- tions, p. 39.

13. Kou, S., and Sun, D. K. 1985. Fluid flow and weld penetration in stationary arc welds. Metallurgical Transactions A 16A: 203-213.

14. Lu, M., and Kou, S. 1988. Power and current distributions in gas tungsten arcs. Welding Journal 67(2): 29-s to 34-s.

15. Duley, W. W. 1999. Laser Welding. New York, N.Y., John Wiley and Sons, p. 76.

16. Mazumder, J., and Voekel, D. 1992. Laser Advanced Materials Processing -- Sci- ence and Applications, eds. A. Matsunawa and S. Katayama. High Temperature Society of Japan. Osaka, Japan. Vo[. 1, pp. 373-380.

17. Tsai, M. C., and Kou, S. 1989. Marangoni convection in weld pools with a free surface. Internal Journal for Numerical Methods in Fluids 9:1503-1516.

18. Limmaneevichitr, C., and Kou, S. 1998. Flow visualization of Marangoni convection in simulated weld pool (a videotape movie), unpublished work. Madison, Wis., University of Wisconsin-Madison.

19. Kamotani, Y., Chang, A., and Ostrach, S. 1996. Effects of heating mode on steady ax- isymmetric thermocapillary flows in microgravity. Journal of Heat Transfer 118:191-197.

20. Limmaneevichitr, C., and Kou, S. 1998. Physical simulation of thermocapillary convection in weld pools. NASA Microgravity Materials Science Conference, NASA/CP- 1999-209092: 393- 398.

21. Kamotani, Y., Lee, J. H., and Ostrach, S. 1992. An experimental study of oscillatory thermocapillary convection in cylindrical containers. Physics of Fluids A 4: 955-961.

22. Oreper, G. M., and Szekely, J. 1984. Heat- and fluid-flow phenomena in weld pools. Journal of Fluid Mechanics 147: 53-79.

23. Pitscheneder, W., Ebner, R., DebRoy, T., and Mundra, K. 1996. Weld pool geometry during high power conduction mode carbon dioxide laser welding. Trends in Welding Re-

search, eds. H. B. Smart-t, J. A. Johnson and S. A. David. Materials Park, Ohio, ASM Interna- tional.

24. Kim, W. H., Fan, H. G., and Na, S. J. 1997. Effect of various driving forces on heat and mass transfer in arc welding. Numerical Heat Transfer, Part A 32: 633-652.

25. Mills, K. C., Keene, B. J., Brooks, R. F., and Olusanya. 1984. Surface tension of 304 and 316 type stainless steels and their effect on weld penetration. Report of the National Phys- ical Laboratory, Teddinton, Middlesex, U.K.

26. Limmaneevichitr, C., and Kou, S. 2000. Experiments to Simulate Effect of Marangoni Convection on Weld Pool Shape. (To be published in the Welding Journal.)

UNMIXED ZONE IN ARC WELDS: SIGNIFICANCE ON CORROSION RESISTANCE OF HIGH

MOLYBDENUM STAINLESS STEELS

By C. D. Lundin, W. Liu, G. Zhou and C. Y. P. Qiao

The nature and the effect of the unmixed zone in dissimilar fusion welds, especially its significance with regard to corrosion resistance, has been studied in this Welding Research Council-sponsored program. Three types of super-austenitic stainless steel (high Mo) (AL-6XN, 254SMO and 654SMO) and five types of fully austenitic nickel-based weld filler metals (Inconel 625, C-22, C-276, 686CPT and P16) were evaluated. Shielded metal arc (SMA), gas metal arc (GMA), gas tungsten arc (GTA) (filler added) and gas tungsten arc autogenous welding processes were used for fabricating weldments of each super-austenitic stainless steel. The employment of these welding techniques provided a full range of unmixed zone formation.

The unmixed zone formation was metallographically evaluated using both optical light microspcopy (OLM) and scanning electron microscopy (SEM) with varied etchants and etching techniques.

The pitting corrosion behavior of the unmixed zone was evaluated using immersion corrosion tests in 10% FeCI 3.

Publication of this document - - WRC Bulletin No. 428 - - was sponsored by the Welding Research Council, Inc.

The price of WRC Bulletin 428 (January 1998, 98 pages) is $110.00 per copy plus $5.00 for U.S. and Canada and $10.00 for overseas postage and handling. Orders should be sent with payment to the Welding Research Council, 3 Park Avenue, 27th Floor, New York, NY 10016- 5902. Phone (212) 591-7956: Fax (212) 591-7183; e-mail: [email protected] or visit our homepage http://www.forengi neers.org/wrc.

W E L D I N G RESEARCH SUPPLEMENT I 135-s

A Synthesis of the Fracture Assessment Methods Proposed in the French RCC-MR Code for High Temperature

D. Moul in, B. Drubay and L. Laiarinandrasana

WRC Bulletin 440 reports work conducted under the PVRC Elevated Temperature Design Committee sponsored by the High Pressure Institute of Japan and the Japan PNC. It is one of three parts of a project to develop simplified nonlinear inelastic methods for application during the early design stages for the Japanese fast breeder reactor program. This bulletin covers the subject of high temperature crack growth with a discussion of the approach used by France in the framework of the development of their RCC-MR Construction Code based on a preliminary version of the A16 defect assessment procedure. The A16 document is presented with its major guidelines. A flow diagram is included that summarizes the procedure and provides guidance for applying the calculation methods. Comparisons with the British R5 and R6 methods are made, and the A16 procedure is also compared to a Japanese method. The report also includes the main experimental data used for validating the A16 procedure. The report presents the A16 procedure, shows comparisons with other defect assessment rules, summarizes the experimental data and provides step-by-step examples of the A16 procedure along with experimental validation summaries. The report concudes with a discussion of the procedure along with recommendation for future work and summarizes the significant conclusions drawn form the collaborative studies.

ISSN: 0043-2326 ISBN: 1-58145-447-3

Library of Congress Catalog Card Number: 85-647116 Number of Pages: 107

The price of WRC Bulletin 440 is $140.00 per copy plus $5.00 for postage and handling in the U.S. and Canada and $10.00 for postage and handling for other locations.

Use the Web site www.forengineers.org/pvrc to purchase this bulletin, or correspond with payment (check, Visa or Mastercard) to the Welding Research Council, 3 Park Avenue, 27th Floor, New York, NY 10016-5902. Phone 212-591-7956; Fax 212-591- 7183; e-mail [email protected].

Review of Existing Fitness-for-Service Criteria for Crack-Like Flaws

P. M. Scott, T. L. Anderson, D. A. Osage and G. M. Wi lkowski

The scope of the work described in this report mainly involved a review of the current practice for making an assessment of the acceptability of a flaw, at one specific "snapshot" in time. In ASME Section Xl terminology, this is analogous to making a flaw assessment using the "end of evaluation period" flaw size. Aspects related to flaw growth, whether it be due to fatigue, creep or some other mechanism, are not rigorously covered in this document.

The main conclusion drawn as a result of this effort is that for the most part the existing flaw evaluation criteria are conservative when compared with experimental data. Even so, there are a number of limitations associated with the application of these criteria that must be considered. These include the following:

• High R/t Ration Components • Undermatching Welds • Questionable Choice of Material Data • Poorly Defined Flaw Size

The following recommendations are made as a result of this effort. 1. It is recommended that any new FFS criteria that evolve as a result of the ASME Post Construction Committee activi-

ties should be based on the failure assessment diagram (FAD) approach. 2. To use such an FAD-based approach, a stress intensity factor (K) solution and limit-load solution must be available

for the geometry of interest. 3. It is recommended that FFS assessment procedures allow assessments at multiple levels of complexity and accuracy. 4. It is recommended that FFS assessment procedures that evolve allow flaw assessments to be performed either deter-

ministically or probabilistically.

Publication of this document - - WRC Bulletin No. 430 - - was sponsored by the Pressure Vessel Research Council of the Welding Research Council.

The price of WRC Bulletin 430 (April 1998, 155 pages) is $175.00 per copy plus $5.00 for U.S. and Canada and $10.00 for overseas postage and handling. Orders should be sent with payment to the Welding Research Council, 3 Park Ave., 27th Floor, New York, NY 10016-5902. Phone (212) 591-7956; Fax (212) 591-7183; e-mail: [email protected] or visit our home page http://www.forengineers.org/wrc.

136-s I MAY 2000

FIRST ANNOUNCEMENT AND CALL FOR PAPERS

ICAWT 2000 m The International Conference on Advances in Welding Technology

GAS METAL ARC WELDING FOR THE 21 ST CENTURY

December 6-8, 2000, Orlando, Florida

This is a landmark conference on the Gas Metal Arc Welding Process (GMAW) and the related Flux Cored Arc Welding (FCAW) process, celebrating 50 years of GMAW, and evaluating ways in which application of the latest developments in GMAW technology can assist users in increasing productivity and quality. International experts will give keynote papers, and the latest process developments will be discussed in five sessions over 3 days. An exhibition will be held in con- junction with the conference. Authors from around the world are invited to submit abstracts. The conference is sponsored by the American Welding Society and the Edison Welding Institute.

Authors should submit the Author Application Form (on reverse side) with an abstract of no more than 500 words by June 15, 2000, preferably by electronic mail ([email protected]). Authors will be notified of acceptance by June 30, 2000. Papers for the program will be selected by a technical committee. Completed manuscripts in camera-ready format will be required by October 1,2000. Companies interested in exhibiting at the conference should contact the AWS Conference Department at (800) 443-9353 ext. 449.

Authors are requested to offer papers appropriate for the theme of the conference, the application of the latest developments in GMAW technology to enhance productivity and quality. Session topics will include the following:

• GMAW power supplies. DC, AC and pulsed welding, process stability, adaptive power supplies, transfer modes, stability, spatter

• Process characterization and optimization. Optimization methods, gas mixtures, defects, modeling, neural nets.

• Process variants. Narrow groove welding, combined laser/GMA welding. • Flux core and metal core welding. Process selection, weld properties, hydrogen

control. • High productivity welding. Extended stickout, twin and tandem welding, rotated arc

welding. • Robotics and automation. Off-line programming, cost benefit, implementation of

automated systems, case studies. • Sensors and process monitoring. Data acquisition and signal analysis, through-the-

arc sensors, optical and other sensors, joint tracking, adaptive welding. • Safety. Fume generation, fume extraction. • Applications. Underwater welding, pipeline welding. Novel applications. • Materials. Galvanized and aluminized steel, high-strength steel, stainless steel,

aluminum, titanium, and nickel alloys.

AUTHOR APPLICATION FORM ICAWT 2000: Gas Metal Arc Welding for the 21 st Century

December 6-8, 2000, Orlando, Florida

Abstract Title:

Author's Name:

How addressed: (Mr., Ms., Dr., Prof., Other):

Title or Position

Organization:

Mailing Address: City: State: Zip/Code: Country: Telephone: Fax: e-mail address:

Coauthors: Name: Organization: Address:

ABSTRACT: • Typed, double spaced, 250-500 words, transmitted with this form. • Application form and abstract must be provided to AWS no later than June 15, 2000.

PAPERS: • Manuscripts in camera-ready format will be required no later than October 1,2000. • Guidelines for submission of manuscripts will be provided to authors selected for the program. • The offer of a paper is taken to imply that an author will be fully funded and available to attend and

present the work. • The bound conference proceedings will be provided to conference participants at the commencement

of the conference.

Wherever possible, the abstract and author application form should be sent by electronic mail to [email protected]. Alternatively, the abstract can be provided on disc in Microsoft Word (6.0 or 7.0 or rich text format), and may also be faxed or mailed to the following address: Conference Department American Welding Society 550 N.W. LeJeune Rd. Miami, Florida, 33126, USA (800) 443-9353 or (305) 443-9353, ext. 278. FAX (305) 443-7559.

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Documents

,, Technology Update on!! GTAW Power Sources Goes Smoothly · Finite Element Analysis of Heat Flow in Single-Pass Arc Welds E. A. Bonifaz A finite element model is developed to predict