W6!7!304E Skin-Pass Mills References

SKIN-PASS MILLSSKIN-PASS MILLS for a perfect finish

METALLURGICAL PLANT and ROLLING MILL TECHNOLOGY

Flat-product rolling mills

SMS SIEMAG

Stress-strain curve.

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Skin-pass millsSMS SIEMAG

TYPICAL APPLICATIONS

Cold-rolled steel strip is something we encounterevery day in one place after another. Surface effects,whether high-gloss, mat or other, communicate animpression of beauty and elegance. Properties thatennoble the products.

In addition to the aesthetic effect, the surface of steelstrip is of technical importance. For example, the cor-rect surface roughness ensures that painted surfaceshave a permanently perfect visual appearance.

Other properties of cold-rolled steel strip remainunnoticed by us. However, they are indispensable for industrial further processing.

Let us take a beverages can, for example, which is fashioned out of thin tinplate in a single deep-drawing operation. To produce it economically, notonly is the right surface quality needed but above alla defined deformation behaviour. Through more pre-cise adjustment of the necessary properties, it hasbeen possible to reduce the weight of the beveragescan by 30 % over the past 25 years.

The decisive process step for this is skin-passingupon completion of the cold strip manufacture. It pro-duces the exact mechanical and geometrical proper-ties that the customer needs for his applications.

ADVANTAGES OF SKIN-PASSING

The objective of skin-passing is to attain the correctyield points and the desired surface characteristics.

Definition of the yield points

Skin-passing causes the unsteady yield-point range,known as the Lüders band, to be transformed into adefined yield point. This serves to improve the flowbehaviour during the deep-drawing operation and toprevent unwanted lines of stress.

Setting of the strip roughness

Setting the desired roughness of the strip surfacewill, for example, enhance the yield of the deep-drawing process or improve the adhesion of paints.

Achievement of perfect strip flatness

Strip flatness is an important property for the firmswhich perform further processing. This is becausegood flatness values allow trouble-free operation oftheir plant and equipment.

SKIN-PASS MILLSSKIN-PASS MILLS for a perfect finish

Before skin-passing After skin-passing

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Flatness of a skin-passedsteel strip.

Skin-pass mills 2

for a perfect finish

Skin-pass mills 4

for every application

Quality features 6

High-tech components

Inline skin-pass mills 10

for all process lines

MMK, Magnitogorsk, Russia 12

Anshan Iron & Steel, Anshan, China 14

Baoshan Iron & Steel, 16

Shanghai, China

ThyssenKrupp Steel Europe, 18

Dortmund, Germany

Offline skin-pass mills 20

for hot and cold strip

Saudi Iron & Steel, 22

Saudi Arabia

ThyssenKrupp Steel USA, 24

Alabama, USA

Salem Steel Plant, India 26

Gazi Metal Mamülleri Sanayi 28

ve Ticaret A.S., Turkey

DCR cold rolling mills 30

for combined reducing and

skin-passing

Dongbu Steel, Kodai, South Korea 30

Aceralia S.A., Spain 31

Rasselstein, Andernach, Germany 32

References for skin-pass mills 34

1999 to 2011

Contents

Products madefrom tinplate.

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SKIN-PASS MILLS SKIN-PASS MILLS for every application

Skin-pass mills are located at the end of the processchain and are essential for the trouble-free furtherprocessing of steel strips.

SKIN-PASS MILLS FOR HOT STRIP

Skin-passed hot strip has many advantages: Skin-passing not only helps to attain perfect strip flatnessand harmonize the yield points but also prevents flowlines and break lines from occurring during the uncoil-ing process. Furthermore, it makes the downstreampickling process easier by initially breaking the scalelayer.

SINGLE SKIN-PASS MILLS

FOR COLD STRIP

Our single skin-pass mills are independent rollingfacilities which usually follow the batch-annealingstage and can be implemented very flexibly. Theycan process both hard strip and ultra-mild strip. They also provide the perfect finish for cold-rolledstainless steel strip.

A special case is represented by what are known as the DCR rolling mills, or DCR temper mills. DCRstands for "Double Cold Reduction". These two-standfacilities combine thickness reduction in the firststand with skin-passing in the second stand. It is alsopossible to use both stands for skin-passing. In thiscase the material properties, such as a defined yieldpoint, are set in the first stand while in the secondstand the desired surface characteristics are trans-ferred to the strip.

INLINE SKIN-PASS MILL

FOR COLD STRIP

Skin-pass mills can also be installed directly “inline”in the exit section of an annealing or hot-dip galvaniz-ing line. The strip can be completed in the processline, and this has several advantages. The effort andexpenditure on coil handling is reduced, enabling pro-ductivity to be enhanced and profitability increased.

TWO-HIGH, FOUR-HIGH

AND SIX-HIGH STANDS

So-called “two-high bright mills” are employed fortreating austenitic stainless steel strip. These skin-pass mills in two-high design provide high-gloss stripsurfaces. Use is also made of four-high stands for ferritic stainless steels.

Four-high stands can be equipped with work rolls of varying diameters. In combination with a given rollforce, this allows a wider range of products to bemanufactured. Smaller work roll diameters reduce the roll force when skin-passing strips made fromhigh-strength steel grades. Work rolls with a largerdiameter also allow very mild steel grades to be skin-passed with an adequately large roll force, along withimprovement of the impressed roughness.

Since 2003 we have been supplying skin-pass millsalso in six-high construction for highly demandingskin-passing tasks.. The strip flatness can be per-fected yet further thanks to the larger adjustmentrange of the six-high mill. Moreover, a wider productmix can be skin-passed.


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The mill stand designs: Two-high, four-high or six-high stands and their technical

characteristics and fields of application

Characteristics Two-high Four-high Four-high stand Six-high stand stand* stand with CVC® plus with CVC® plusWork roll bending - + + +

CVC® work-roll shifting + - + +

Intermediate roll bending - - - +

Strip elongation (%) 1 to 2 1 to 4 2 to 4 2 to 4

Flatness + ++ ++(+) +++

Surface quality ++ ++ ++ ++

*Chief field of application: Stainless steel

Arrangement of skin-passingmills in the process chain.

Skin-pass mill for hot strip

Single skin-pass mill

Inline skin-pass mill

Single skin-pass mill for stainless steel

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THE MARKET

Our skin-pass mills are equipped with technologicalfeatures that have proven their value in worldwideoperation and satisfy the most stringent require-ments of our customers. By applying the most up-to-date technology we fulfil the demand for a widerrange of products, optimum product quality and eco-nomic plant operation. As standard features, our skin-pass mills possess hydraulic roll-gap adjustmentsystems for controlling the roll force and work-rollbending systems for influencing the strip flatness.They also include the extended bending systemamong their special equipment items.

WORK ROLL DIAMETERS

The use of different work roll diameters in combina-tion with a given roll force enables the product rangeto be extended above all by stronger grades.

BENDING SYSTEM AND CVC® PLUS

For the skin-passing of soft grades, the increasing of the roll diameter very soon reaches its limitations.With the aid of our extended bending system, theroll force can be safely lowered to values below100 kN. For this, the backup rolls are raised up in the four-high and six-high stands. The necessary rollforce is attained solely by means of the work rollbending or, in the case of the six-high stand, by theintermediate roll bending. This, for example, allowsthe controlled skin-passing of mild IF steels.

We make use of CVC® plus for the production ofsteel strips with excellent flatness. In addition, a CVC® compensation grind on the backup rollsensures a well-balanced distribution of the contactload, thus reducing the wear on the rolls.

LOW-QUANTITY LUBRICATION

Low-quantity lubrication (LQL) is a lubrication conceptfor skin-pass mills which is also suitable for utilizationin the final millstand of a tandem mill. In this system,only that precise quantity of lubricant is appliedwhich is needed in the roll gap at that moment inorder to reduce the friction.

This process has the following advantages in skin-pass mills:The service life of the work rolls is morethan doubled.The roll force is reduced.The required lubrication quantities are reduced,which has a positive effect on the environmentalcompatibility.The strip surfaces are cleaner.The strip flatness is excellent since the processopens up new possibilities for controlling theskin-passing operation.The application of inert gas onto the work rolls andonto the strip in the exit section enables the rollsto retain their roughness for a longer period andtheir service life is lengthened accordingly. Down-stream cleaning of the strip is no longer necessary.Thanks to the compactness of the system, exist-ing plants can be retrofitted without incurringgreat expenditure.

Conclusion: Low-quantity lubrication increases theproportion of products able to be “wet skin-passed”and minimizes the operating costs. The lower quan-tity of lubricant required also signifies enhanced envi-ronmental compatibility.

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QUALITY FEATURESQUALITY FEATURES High-tech components


The LQL system.

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The lubricant is atomized by compressed air.

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FLATNESS MEASURING ROLLER

The measurement of flatness is of decisive impor-tance for the production of top-quality skin-passedsteel strip. SMS Siemag therefore constructs its ownflatness measuring roller, based on the BFI principle.The roller is characterized by a closed surface, whichnot only avoids marks on the strip but also allows the roller to be coated with any desired material. Thesensors can be adapted very flexibly in accordancewith the multizone cooling system. This enables notonly current demands on the flatness system to befulfilled but also future demands.

ONLINE RESIDUAL OIL DETECTION

Rapid, precise and continuous detection and recordingof even the slightest quantities of residual oil on cold-rolled strip is nowadays absolutely essential for qualityassurance and for the avoidance of rejects due to cor-rosion. For this reason, SMS Siemag uses a measuringmethod developed jointly with the firm of Kienzle Pro -zessanalytik, operating on the basis of laser-inducedfluorescence spectroscopy. This online measuring sys-tem combines numerous advantages:

It enables the uninterrupted identification and documenting of residual oil over the width andlength of the strip.Tramp oil from leaks is detected reliably.Rejects caused by rust are reduced by rapid detection of an excessive residual oil content.Finally, the system supports the optimization of the lubricant quantity and its utilization in amanner compatible with consumption.

T-ROLL®

Our skin-pass mills are equipped with highly devel-oped open and closed-loop control systems. Depend-ing on the application, the mills possess technologi-cal recording and control systems for Roll forceStrip elongationStrip tension, flatnessRoughnessOil residuesMechanical wear

Our T-roll® technology package, for example, makespossible the effective pilot control of the strip elonga-tion. Above all during start-up and acceleration of themill, this enables off-gauge lengths to be reducedand the strip elongation and flatness to be keptwithin the closest tolerances.

Conclusion: Thanks to their high-tech components,our skin-pass mills are capable already today of satis-fying the demands of tomorrow. Future challengesrelating to skin-pass mills aim at greater flexibility asregards the strip elongations and the product rangeto be rolled. The demands made on surface qualitywill likewise become more stringent. At the sametime, the operating costs have to be lowered. A con-tribution to this can be made by the sparing utiliza-tion of lubricants, which is sensible also from theenvironmental point of view.

QUALITY FEATURESQUALITY FEATURES High-tech components

Online measuring system for measuringthe residual oil quantity.


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Flatness measuring roller.

Operating results for stripelongation control by meansof T-roll® pilot control.

Elongation

Rolling speed [m/s]

Output feed forward module [kN]

Rolling force [kN]

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INLINE SKIN-PASS MILLS INLINE SKIN-PASS MILLS for all process lines

NON-STOP STRIP QUALITY

Integrated into the exit section ofannealing or hot-dip galvanizing linesare inline skin-pass mills which pro-vide the perfect finish to the strip processing.

From 1999 to 2011 alone we supplied37 inline skin-pass mills, of which:20 mills were for operation incontinuous hot-dip galvanizing linesnine mills for operation incontinuous annealing linestwo mills for operation incontinuous pickling linesthree mills for operation incombined continuous annealing and pickling linestwo mills for operation in combinedcontinuous annealing and hot-dipgalvanizing linesone mill for operation in a combinedcontinuous pickling and hot-dip galvanizing line


Skin-pass mill in acontinuous annealing line.

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MAGNITOGORSK IRON & STEEL, MAGNITOGORSK IRON & STEEL,Magnitogorsk, Russia

SKIN-PASS MILLS

in the new COLD STRIP COMPLEX

The task MMK is one of the Russia’s leading steel producersand is expanding its production of high-grade cold-rolled and galvanized strip. These strips are intendedabove all for the manufacture of automotive outer-body and interior parts and, furthermore, for domes-tic appliances and for the construction industry.

Our solution Two four-high skin-pass mills with CVC® plus in acombined continuous annealing and hot-dip galvaniz-ing line and in a continuous hot-dip galvanizing line.Work rolls with two different diameters are used forskin-passing the required range of products. Besidesthe mechanical equipment, we also supply the elec-trical and automation systems for the skin-pass milland the entire new cold strip complex with strip pro-cessing lines and a combined pickling line/tandemcold mill.

The mechanical components are produced in ourHilchenbach workshop in conformity with the highestquality standards. A rapid start of production isensured by pre-assembly and function tests on themost important plant components.

The result The mills will go into operation in 2011. The skin-pass mills in the exit section of the two strip pro-cessing lines are able to skin-pass the entire productrange comprising mild to high-strength steels.

New cold strip complex withtwo skin-pass mills.

Strip processing lines at MMK.

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TECHNICAL DATA

Production data

Rolled stock GI, CQ, DDQ,EDDQ, HSLA, BH,DP, TRIP, CP

Strip width 850 to 1,880 mm

Strip gauge 0.3 to 3.0 mm

Technical data

Mill stand design Four-high standwith CVC® plus

Roll diameter

Work roll No. 1: 400 to 450 mm


Backup rolls 1,250 to1,150 mm

Rolling speed 220 m/min

Roll force Max. 18 MN

Technical features CVC® on the workrolls, roll bending,hydraulic roll-gapadjustment

Perfect surfaces.

Inline skin-pass mill.

Mill stand with rolls, seen fromthe operator side.

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ANSHAN IRON & STEELANSHAN IRON & STEELAnshan, China

WORLD'S FIRST SKIN-PASS MILL

IN SIX-HIGH CONSTRUCTION

The task Anshan Iron & Steel Company has built a new continuous annealing line in Anshan in the Chineseprovince of Liaoning. This strip processing lineenables more than 1,000,000 t of high-quality steelstrip to be manufactured each year in the grades CQ, DQ1, DQ2, DDQ, EDDQ, S-EDDQ, HSS andTRIP, intended above all for use in the automotiveindustry.

Our solution Our solution is a six-high skin-pass mill with CVC® plusin a continuous annealing line. This is the first timethat SMS Siemag has constructed a skin-pass mill asa six-high unit and equipped it with CVC® plus technol-ogy with a view to satisfying the stringent demands of this customer with regard to strip quality and, inparticular, flatness. In combination with the work-rolland intermediate-roll bending, the roll-gap geometrycan thus be adapted dynamically to the strip profile,enabling the desired flatness results to be achieved.The backup rolls are fitted with a CVC® compensationgrind to allow a well-balanced distribution of the con-tact load. This reduces wear on the rolls.

The result Outstandingly good strip flatness and surface resultsare achieved by the skin-pass mill, which was putsuccessfully into operation in 2006. The annualcapacity is around 1,000,000 t.

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TECHNICAL DATA

Production data

Rolled stock CQ, DQ, DDQ,EDDQ, HSQ, TRIP

Strip width 1,000 to 1,980 mm


Technical data

Mill stand design Six-high stand withCVC® plus

Roll diameter

Work rolls 420 to 470 mm

Intermediate rolls 510 to 560 mm

Backup rolls 1,000 to 1,150 mm


Roll force max. 12 MN

Technical features CVC, CVC-IMR,HGC, WRB, IRB

Intermediate rolls with CVC® plus, hydraulicroll-gap adjustment systems, work-roll andintermediate-roll bending

Threaded strip.

Upper strip edge blow-off device.

Lower strip edge blow-off device.

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Housing window in six-high constructionwith threaded strip.


BAOSHAN IRON & STEELBAOSHAN IRON & STEELShanghai, China

A SOFT FINISH

for mild STEELS

The task In 2005 Baosteel had placed an order with us forextension of the cold rolling and strip processinglines at the Shanghai-Baoshan location. This orderincluded the erection of a CVC skin-pass mill in theexit section of the continuous annealing line. Thestrips processed at the above location are made ofparticularly mild steels which are used, for example,for automotive outer shells.

Our solution Six-high skin-pass mill with CVC® plus in a continu -ous annealing line. Since mild IF steels also runthrough the CAL in addition to high-strength steelgrades, the skin-pass mill possesses work rolls withtwo different diameters and the extended bendingsystem. The EBS makes it possible to lift up thebackup roll and to apply the very small amount of roll force solely with the aid of the intermediate roll bending.

The result The six-high skin-pass mill was put successfully into operation in 2008. The EBS allows the roll forceto be varied between 300 and 1,800 kN. The change-over to EBS is specified by the rolling schedule andtakes place automatically. The annual capacity is729,000 t.

Top: Skin-pass mill. Middle: Skin-pass mill between entryand exit accumulator. Bottom: Continuous annealing line.

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TECHNICAL DATA

Production data

Rolled stock CQ, DQ, DDQ,EDDQ, SDDQ andHSS



Strip elongation max. 2%

Technical data

Mill stand design Six-high stand withCVC® plus

Roll diameter



Intermediate rolls 620 to 700 mm




Technical features CVC® plus on theintermediate rolls

Hydraulic roll-gap adjustment system, work-roll and intermediate-roll bending, extendedbending system (EBS)

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THYSSENKRUPP STEEL EUROPE,THYSSENKRUPP STEEL EUROPE,Dortmund, Germany

SKIN-PASSING WITH LQL

The task

ThyssenKrupp Steel Europe AG had placed an orderwith us in 2006 for modernization of the continuousannealing line in the cold rolling mill at the Dortmundlocation. In this production line, ThyssenKruppprocesses a wide range of steel grades, from mild IFsteels to high-strength TRIP grades. The objective ofthe modernization is to enhance the plant availabilityand to improve the product characteristics above all in respect of the requirements of the automotiveindustry. The order also included the modernizationof the inline skin-pass mill.

Our solution

Four-high skin-pass mill with CVC® plus, work rollswith two different diameters and low-quantity lubrica-tion (LQL). The utilization of different roll diametersenables TKS to skin-pass both mild and higher-strength steel grades.

The Dortmunders were convinced of the value of the LQL low-quantity lubrication system thanks tothe emulsion system no longer being needed, to thecompact nature and simplicity of installation of theequipment and to the low oil consumption. Togetherwith our X-Pact automation system and our flat -ness measuring roller, higher plant availability andenhanced product quality were achieved as the modernization objectives.

The result

The mill, with an annual capacity of 780,000 t,was put into operation in 2007. It involves a new,pioneering equipment concept. It improves theconditions for further processing, contributesdecisively to lowering the operating costs andhas a positive influence on environmental com-patibility. The plant configuration described hereis attractive not only for new plants but also formodernization concepts for existing mills, notleast because the conversion work only requiresshort downtimes.

Entry section: The lubricant is atomized by compressed air.Flatness measuring roller.

Housing window.

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TECHNICAL DATA

Production data

Rolled stock Mild IF steels toTRIP grades



Technical data

Mill stand design Four-high standwith CVC® plus

Roll diameterWork roll No. 1 400 to 450 mmWork roll No. 2: 600 to 650 mmBackup rolls 990 to 1,100 mm

Rolling speed max. 412 m/min


Strip tensions 125 kNEin- und Auslauf

Technical featuresHydraulic roll-gap adjustment system,work roll bending, low-quantity lubrication

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OFFLINE SKIN-PASS MILLSOFFLINE SKIN-PASS MILLS for hot and cold strip

MAXIMUM FLEXIBILITY

Offline skin-pass mills for hot andcold strip from SMS Siemag arestand-alone rolling facilities whichcan be operated flexibly from variousprocess stages.

In the years between 1999 and 2011SMS Siemag supplied 15 offlineskin-pass mills for hot and cold strip,including stainless steel strip.

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Figure at top: Control room. Bottom: Skin-pass millwith pay-off reel in the entry section.

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SAUDI IRON & STEEL (HADEED)SAUDI IRON & STEEL (HADEED) Sar-Al-Jubail, Saudi Arabia

SKIN-PASS MILL FOR HOT STRIP

The task

Founded in 1979, the Saudi Iron & Steel Company(Hadeed) is Saudi Arabia's largest steel producer.Besides long products, the company manufactureshot and cold-rolled flat steel products. A skin-passmill for the skin-passing and recoiling of hot-rolledstrips from steel grades with a low carbon contentneeded to be erected at the Sar-Al-Jubail location.

Our solution

Our solution was to provide a skin-pass mill for hotstrip in four-high construction. We supplied all themechanical equipment for the mill, comprising anoffline coil preparation station, the skin-pass mill-stand, the pay-off and tension reels and an inspectiontable on which the strip quality can be examined. Inaddition, a hydraulic shear was installed in the exitsection. This shear is used for cutting off the striphead end, cutting out samples and dividing coils intovarious strip lengths.

The positive and negative work roll bending makespossible a maximum control range for the roll crown.The mill was equipped with a flatness measuringroller and control system in order to ensure excellentflatness results and observance of tolerances. Per-fect winding of the finished coils is thus safeguarded.One payoff reel and one tension reel were providedin tried-and-tested design and fitted with expandablemandrels.

The result

The mill has been producing since 2006 and itattains a maximum rolling speed of 460 m/min. It is designed for the skin-passing of strips ingauges of 1.2 to 6.0 mm. The annual capacity is 700, 000 t.

Figure at top: Tension reel inexit section.

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TECHNICAL DATA

Production data

Rolled stock Steel strips withlow carbon content



Strip elongation 0.5 to 3.0 %

Technical data

Mill stand design Four-high stand

Roll diameter

Work rolls 470 to 520 mm



Roll force 15 MN

Annual capacity 700,000 t

Technical features- Automatic flatness control- Automatic control of elongation- Automatic roll-gap control- Work roll bending

The new plant complex in Alabama. The offline skin-pass mill issituated in the cold rolling mill for carbon steel grades.

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THYSSENKRUPP STEEL USATHYSSENKRUPP STEEL USACalvert /Alabama, USA

THE OPTIMUM SOLUTION

for MILD to HIGH-STRENGTH STEELS

The task

ThyssenKrupp Steel and ThyssenKrupp StainlessUSA have built a new manufacturing complex for hotand cold strip in the US federal state of Alabama.Strips made from carbon steel and stainless steelgrades are produced and surface-finished in the newworks. The main customers for these high-qualityproducts are automotive manufacturers and suppliersin the south of the USA, as well as the constructionsector and the household appliances industry.

ThyssenKrupp Steel Europe had placed a major orderwith us in 2007 for the erection of several rollingfacilities and strip processing lines for this complex.A total of five skin-pass mills form part of the coldrolling mill and strip processing lines. Three of theskin-pass mills are incorporated in hot-dip galvanizinglines as inline facilities, and one mill is installed in acontinuous annealing line. The fifth mill is an offlineskin-pass mill, used mainly for the skin-passing of hotstrip and for the refinishing of cold-rolled strips.

Our solution

Mill No. 5 is an offline skin-pass mill in four-high con-struction, designed for the skin-passing of annealedand hot-dip galvanized material. It possesses workroll bending and is equipped for wet skin-passing. Itcan also recoil high-strength material. One of its spe-cial features is that it is fitted out for operation withlow-quantity lubrication in the strip entry section.

The result

The offline skin-pass mill has an annual capacity ofup to 700,000 t. It treats strips in widths between800 and 1,870 mm. The minimum strip gauge is 0.3and the maximum gauge is 3 mm. The low-quantitylubrication lowers the consumption of cooling lubri-cants and reduces the roll force, thereby lengthen-ing the service life of the work rolls. It ensuresenhanced product quality at lower investment andoperating costs.

Roll-changing.

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TECHNICAL DATA

Commissioning 2011

Production data

Rolling stockCQ, DQ, DDQ, EDDQ, HS/BH, mild steels,annealed and unannealed DP steels (high-strength grades)



Coil weight max. 36 t

Strip elongation 0.3 to 2.5 %

Technical data



Roll force 13 MN

Capacity 700,000 t/year

Technical features- Hydraulic gap control (HGC),- work roll bending (WRB)

This ensured fast commissioning.

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SALEM STEEL PLANT SALEM STEEL PLANT Salem, Indien

TECHNICAL HIGHLIGHTS PROVIDE

A GLOSSY FINISH FOR STAINLESS

STEEL STRIP

The task

Salem Steel Plant (SSP), which belongs to the SailGroup, in Salem in Tamil Nadu province in the south-west of India, placed an order with us in 2008 to sup-ply a skin-pass mill for stainless steel strips. After thestainless steel strip has been cold-rolled and recrys-tallized, it is skin-passed. The purpose of this “soft”rolling process is to produce high-gloss surfaces andto achieve the desired mechanical strip properties,such as deep-drawing strength.

Our solution

The skin-pass mill in two-high reversing design pos-sesses a mathematical model for pass schedule cal-culation with a view to attaining the desired produc-tivity and quality of the stainless steel strips. Theautomatic strip cleaning system ensures a clean stripsurface. The hydraulic roll-gap adjustment systemallows optimum adaptation of the roll gap to thestrip. The top and bottom bright-finishing rolls are fitted with a polishing device for removing dirt parti-cles from the rolls. To prevent the strip head endfrom causing marks on the rolls during the threadingof the strip, a threading guard was installed for thetop and bottom rolls. Finally, the semi-automatic roll-changing device ensures quick changing and safehandling. The millstand was fabricated in our Hilchen-bach workshops and pre-assembled together withthe entry and exit equipment so as to guaranteeshort installation times and successful commission-ing. All hydraulic and electrical movement sequenceswere tested during this procedure.

The result

The rolling facility, in two-high reversing construc-tion, is designed for stainless steel strips ingrades AISI 200, 300 and 400. The mill can rollstrips in widths from 600 to 1,300 mm andgauges from 0.3 to 4.0 mm. With a millstand drivepower of 700 kW, it can attain maximum rollingspeeds of 600 m/min. The intended capacity is100,000 t. Commissioning took place in 2009.

The mill was pre-assembled and testedin our workshop.

Installation of the mill stand.

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TECHNICAL DATA

Year of commissioning 2009

Production data

Rolled stock AISI 200, 300 and400



Technical data

Mill stand design Two-high stand

Roll diameter max. 800 mm



Strip tension max. 200 kN


Technical features- Hydraulic roll-gap adjustment system AGC- Oscillating roll polishing device- Innovatory strip cleaning system- Threading guard for top and bottom rolls- Semi-automatic roll-changing- Anti-crimping rolls in the entry and exit sections

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GAZI METAL MAMÜLLERI GAZI METAL MAMÜLLERI Karasu, Türkei

SKIN-PASS MILL FOR C AND SI

STEEL GRADES WITH AN OPTION

FOR EXTENSION INTO A DCR MILL

The task

On behalf of the Turkish company of Gazi MetalMamülleri, SMS Siemag is building a new productionfacility for carbon-steel and silicon-steel cold stripnear to the town of Karasu. With the finished strip,our customer will supply the automotive industry andmanufacturers of household appliances, for example.For the first stage of construction, the supply scopeincludes a semi-continuous pickling line with an incor-porated acid regeneration plant, a reversing cold millin six-high construction with CVC® plus technology as well as a skin-pass mill in four-high construction. A special feature of this order is that provision ismade right at the beginning for the extension of theproduction facility in a second construction stage. In the second stage, Gazi Metal wishes to attain anoverall annual production of 700,000 t and, in addi-tion, produce tinplate intended for the manufactureof beverage and foodstuffs cans.

Our solution

The skin-pass mill is of four-high design and isequipped with hydraulic roll gap adjustment. In thesecond phase of construction, the mill is to beextended by a second millstand. In this way, theskin-pass mill will be extended to become a so-calledDCR mill (Double Cold Reduction) for the processingof tinplate. In addition to skin-passing, the DCR millallows thickness reduction of the strip, which is per-formed in the first millstand while skin-passing takesplace in the second stand. The foundations neces-sary for the extension are designed and constructedaccordingly right at the beginning. The existing ten-sion reel can be relocated so as to enable the secondmillstand to be erected later at this position.

The result

The skin-pass mill processes strips made from car-bon steel and silicon steel in widths ranging from600 to 1,500 mm. The thickness range extendsfrom 0.25 to 3.0 mm. The maximum rolling speedis 1,000 m/min. The annual capacity is around300,000 t. This will rise to 475,000 t after the millhas been extended by a second stand.

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TECHNICAL DATA

Commissioning 2013

Production data

Rolled stock Low-carbon steels,silicon steels



Technical data


Roll diameter

Work rolls 400 to 450 mmBackup rolls 1,050 to 1,200 mm

Rolling speed 1.000 m/min

Roll force 18 MN

Technical features HGC

TECHNICAL DATA

Commissioning 1998

Production data

Rolled stock Low-carbon steels


Strip gauge 0.2 to 0.6 mm (entry section)0.15 to 0.36 mm (exit section)

Thickness reduction max. 40 %in the first stand (DCR operation)

Strip elongation max. 1 %in the second stand (DCR operation)

Strip elongation max. 2 %during skin-passing

Coil weight 45 t

Technical data

Mill stand design Four-high (CVC 4)

Roll diameter Stand 1: 360 to 400 mmStand 2: 510 to 560 mm

Rolling speed Skin-passing: 2,000 m/minDCR operation: 1,600 m/min

Roll force 12 MN


Technical features- CVC, - work roll bending,- multi-zone cooling, - DS system (Dry Strip)

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DCR COLD ROLLING MILLSDCR COLD ROLLING MILLS

Combined REDUCING and SKIN-PASSING

Two-stand DCR temper mills (Double ColdReduction) combine reduction in the first standwith skin-passing in the second stand. Thisenables the material properties and the surfaceroughness to be set in a very carefully targetedmanner for tinplate. This guarantees trouble-free further processing.

Reference plant: Dongbu Steel,South Korea.

DCR mill at Aceralia, Echevarri,Spain.

DCR mill at Dongbu Steel,Kodai, South Korea

TECHNICAL DATA

Commissioning 2000

Production data

Rolled stock Low-carbon steels


Strip gauge 0.15 to 0.6 mm(entry section)min. 0.14 mm(exit section)

Thickness reduction max. 40 %in the first stand (DCR operation)

Strip elongation max. 1 %in the second stand (DCR operation)

Strip elongation max. 2 %during skin-passing

Coil weight 23 t

Technical data

Mill stand design Four-high (CVC 4)

Roll diameter Stand 1:400 to 360 mmStand 2:560 to 510 mm

Rolling speed 2.200 m/min

Roll force 12 MN

Capacity Skin-passing:100,000 t/yearDCR operation:230,000 t/year

Technical features- CVC, - DS system (Dry Strip)

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Reference plant:Aceralia S.A., Spain.

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RASSELSTEIN GMBHRASSELSTEIN GMBHAndernach, Germany

MODERNIZATION OF THE

TWO-STAND DCR TEMPER MILL

The task

At its Andernach location Rasselstein GmbH, whichbelongs to ThyssenKrupp Steel Europe, produces tin-plate for packaging manufacture. Following the clo-sure of production facilities at ThyssenKrupp Steel 'sDortmund location, it became necessary to expandthe production capacities at Andernach in order tosafeguard the firm's leading position in tinplate andto cater for the present and future tinplate require-ments of the packaging industry. The two-stand tem-per mill was therefore relocated from Dortmund toAndernach and comprehensively modernized.

For tinplate manufacture, the hot-rolled strip is pick-led and then reduced in a tandem mill. Followingdegreasing and annealing, it is temper-rolled andskin-passed on the two-stand DCR mill. The DCRcold rolling mill allows wet skin-passing and thick-ness reduction by up to 30 percent. The double-reduced material obtained in this way signifies thesaving of material for the customer because smallerthicknesses are compensated by higher strength.The temper rolling process in the DCR mill preparesthe strip for further surface-finishing and coating. The DCR mill thus occupies a central position in thisprocess sequence. A further important concern withregard to the revamp was to safeguard the highestquality standards.

The purpose of the modernization was toachieve the following objectives:To maintain in good condition and to reuse the components of the old millTo change the rolling directionTo process strips of greater widthTo increase the coil weightShort coil sequences

Our solution As part of the highly demanding revamp of thetwo-stand DCR temper mill in four-high construc-tion, we supplied components and equipment for the coil preparation station and the entry sec-tion, for the millstand and intermediate standarea, for the exit section with tension reel andfor the coil transfer car. Furthermore, our supplyscope included the hydraulics and utilities sys-tems, the wet skin-passing system, the fume-exhaust and cleaning system and the protectiveequipment. After dismantling, essential compo-nents such as mill housings, bending system,work roll and backup roll chocks were reworkedin our workshop and then pre-assembled forinspection purposes.

The result

In mid-December 2003 the DCR temper millcommenced regular operation at the new loca-tion following a short revamp period. The mill is designed for an annual capacity of 800,000 t.The width range of the temper-rolled and skin-passed cold strip is between 600 and 1,400 mm.The strip gauges at the entry and exit sectionsare between 0.12 and 0.5 mm. A strip thicknessreduction of four to 30 % is attained in the firststand. In the second stand a strip elongation of0.6 to 1.4 % is achieved.

Two-stand DCR mill in four-high constructionat Rasselstein in Andernach.

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TECHNICAL DATA

Year of commissioning 2003

Production data

Rolled stock Tinplate



Thickness reductionin the first stand 4 to 30 %

Strip elongationin the second stand 0.6 to 1.4 %

Coil weight max. 35 t

Technical data


Roll diameter 503 to 563 mm

Rolling speed 2,250 m/min

Roll force 15 MN


Technical features Hydraulic gap control, DS system (Dry Strip)

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REFERENCES1999 to 2011REFERENCES1999 to 2011

Inline skin-pass mills

1. Four-high stand in a continuous annealing line Pro-Tec Coating Company, USA

2. Six-high stand with CVC® plus in a continuous annealing line Handan Iron & Steel, China

3. Four-high stand in a continuous hot-dip galvanizing line Ilva, Italy

4. Four-high stand in a continuous hot-dip galvanizing line Severstal Columbus, USA

5. Six-high stand with CVC® plus in a continuous annealing line Shougang Group, China

6. Four-high stand with CVC® plus in a continuous Magnitogorsk Iron & Steel Works, Russia hot-dip galvanizing line

7. Four-high stand with CVC® plus in a combined continuous Magnitogorsk Iron & Steel Works, Russia annealing and hot-dip galvanizing line

8. Four-high stand in a continuous hot-dip galvanizing line Shougang Group, China

9. Four-high stand in a continuous hot-dip galvanizing line Shougang Group, China

10. Six-high stand with CVC® plus in a continuous annealing line Shougang Group, China

11. Four-high stand in a continuous annealing line ThyssenKrupp Steel USA, USA

12. Four-high stand in a continuous hot-dip galvanizing line ThyssenKrupp Steel USA, USA



15. Four-high stand in a continuous hot-dip galvanizing line Ilva, Italien

16. Four-high stand in a continuous hot-dip galvanizing line Ilva, Italien

17. Four-high stand for hot and cold-rolled strip in an annealing and pickling line Marcegaglia, Italy

18. Four-high stand in a continuous hot-dip galvanizing line Nucor, USA

19. Four-high stand in a continuous annealing line, equipped for low-quantity lubrication in combination with liquid nitrogen ThyssenKrupp Steel Europe, Germany

20. Six-high stand with CVC® plus in a continuous annealing line Baoshan Iron & Steel, China

21. Four-high stand in a continuous hot-dip galvanizing line Severstal Columbus, USA

22. Four-high stand in a continuous hot-dip galvanizing line US Steel, Czech Republic

23. Four-high stand in a continuous annealing and pickling line DMS (France) for Taiyuan Iron & Steel, China

24. Four-high stand in a continuous annealing and pickling line ThyssenKrupp Acciai Speciali Terni, Italy

25. Four-high stand in a continuous hot-dip galvanizing line Wuhan Iron & Steel, China

26. Six-high stand with CVC® plus in a continuous annealing line Wuhan Iron & Steel, China



29. Six-high stand with CVC® plus in a continuous annealing line Anshan Iron & Steel, China

No. Plant type Customer

35

30. Four-high stand in a continuous hot-dip galvanizing line Maanshan Iron & Steel, China

31. Four-high stand in a continuous pickling line Marcegaglia, Italy

32. Four-high stand in a continuous hot-dip galvanizing line SeAH Steel, South Korea

33. Four-high stand in a continuous hot-dip galvanizing line Vega do Sul (ArcelorMittal), Brazil

34. Four-high stand in a continuous pickling line Baoshan Iron & Steel, China

35. Four-high stand in a continuous hot-dip galvanizing line Salzgitter Flachstahl, Germany

Offline skin-pass mills for cold strip

36. Four-high stand for silicon steel strip Gazi Metal Mamülleri, Turkey

37. Two-high stand with two reversing reels and equipment for strip cleaning Salem Steel, India

38. Four-high stand ThyssenKrupp Steel USA, USA

39. Four-high stand JSW Steel, India

40. Four-high stand Severstal Columbus, USA

41. Four-high stand Jinan Iron & Steel, China

42. Four-high stand Handan Iron & Steel, China

43. Four-high stand for wet skin-passing Ilva, Italy

44. Four-high stand Arania, Spain

45. Four-high stand Cia Siderurgica Nacional, Brazil

46. Four-high stand Vega do Sul (ArcelorMittal), Brazil

47. Two-high stand with CVC® Shanghai Krupp Stainless, China

48. Two-high stand G Steel Public Co., Thailand

49. Four-high stand ThyssenKrupp Steel Europe, Germany

Offline skin-pass mills for hot strip

50. Four-high stand Saudi Iron & Steel, Saudi-Arabia

DCR rolling mills for reducing and skin-passing

51. Inline four-high stands with CVC® Shougang Jingtang, China

52. Offline four-high stands with CVC® Shougang Jingtang, China

53. Four-high stands with CVC® Dongbu Steel, South Korea

54. Four-high stands with CVC® Aceralia, Spain

55. Offline four-high stands Rasselstein, Germany

P C No. Plant type Customer

SMS SIEMAG AG

Strip Processing Lines Division

Walder Strasse 51-5340724 Hilden, Germany

Phone: +49 (0) 211 881-4618Telefax: +49 (0) 211 881-4212

E-mail: [email protected]: www.sms-siemag.com

SMS SIEMAG AG

Hot and Cold Rolling Mills Division

Wiesenstrasse 3057271 Hilchenbach, Germany

Phone: +49 (0) 2733 29-1800Telefax: +49 (0) 2733 29-1782

E-mail: [email protected]: www.sms-siemag.com

MEETING your EXPECTATIONS

W6+7/304E

1000/01/12 .Ky . Printed in Germany

“The information provided in this brochure contains a general description of the performance characteristics of the products concerned. The actual products may not always have thesecharacteristics as described and, in particular, these may change as a result of further developments of the products. The provision of this information is not intended to have and willnot have legal effect. An obligation to deliver products having particular characteristics shall only exist if expressly agreed in the terms of the contract.”

Documents

W6!7!304E Skin-Pass Mills References