Solid Projections (Solid State Welds). Solid Projections Lesson Objectives When you finish this...

Solid Projections

(Solid State Welds)

Solid Projections

Lesson ObjectivesWhen you finish this lesson you will understand:• Solid State Weld as applied to projections and studs• Applications of Solid Projection Welds

Learning Activities1. View Slides; 2. Read Notes, 3. Listen to lecture4. Do on-line

workbook

KeywordsSolid Projection Weld, Solid State Weld, Swelling

Resistance welder Manufacturers Association Bulletin # 35

Resistance welder Manufacturers Association Bulletin # 35

Current Flow Heats Pipe

Heat FlowsInto Cold PlateThicker Plate = More Heat Loss

Resistance welder Manufacturers Association Bulletin # 35

Current Flow in the Solid Projection

Current Density Less in Thicker Sheet

Resistance welder Manufacturers Association Bulletin # 35

Progression of Projection Collapse for a Simple Angled Projection

Resistance welder Manufacturers Association Bulletin # 35

Short Weld Time Low Weld Force

Proper Weld ConditionsNote Swelling of ODSlight Swelling of ID

Excessive Weld TimeExcessive Weld Force

Proper Restricted Width WeldNo Swelling of OD

Resistance welder Manufacturers Association Bulletin # 35

PhotomicrographsOf Full WidthSolid Projection Welds

Resistance welder Manufacturers Association Bulletin # 35

PhotomicrographsOf Restricted WidthSolid Projection Welds

Parameters

The Welding Parameters appear to be more dependent on Sheet Thickness than on Pipe Thickness

Resistance welder Manufacturers Association Bulletin # 35

There is a parameter limit which exceeded results in excessive pipe swelling

Excessive Swelling

Acceptable Swelling

Resistance welder Manufacturers Association Bulletin # 35

Weld Force

Progression of Projection Collapse for a Beveled Annular Projection

Typical Screw & Stud Parts for Projection Welding

[Reference: Resistance Welding Manual, p.3-6, RWMA]

Correct & Incorrect Location of Annular Projection

[Reference: Resistance Welding Manual, p.3-5, RWMA]

Correct Projection Incorrect Projection

Application for Welding Studs or Bushing into Metal Opening

[Reference: Resistance Welding Manual, p.3-5, RWMA]

Electrode

Electrode

Electrode

Electrode

Weld

Start of Welding Finish of Welding

Application of Annular Projections

[Reference: Welding Handbook, Volume 2, p.564, AWS]

Weld

Weld

Tight Joint

Relief forUpset Metalto Fill in

(a) (b)

(c) (d)

Threaded Boss

Shoulder Stud

Typical Projection Weld Fasteners

Weld Bolts

Weld Pins

Weld Nuts and Pads

[Reference: Resistance Welding Manual, p.3-6, RWMA]

Illustrating Use of Insulated Locating Pin for Welding Nut

[Reference: Resistance Welding Manual, p.3-7, RWMA]

Insulated Steel Pin withShoulder

WeldElectrode

Electrode

Electrode

Electrode

Recessed Electrode for Locating Nut for Welding

[Reference: Welding Handbook, Volume 2, p.567, AWS]

Weld

Electrode

Electrode

Electrode

ElectrodeWeldNut

Two Methods to Provide Accurate Location for Projection Welding Bolts to Sheet

[Reference: Resistance Welding Manual, p.3-8, RWMA]

Flat Spring

Drill Hole in Electrodeto Clear Threads

Bolt Retainer

Sheet Metal

Insulation

ProjectionWeld Bolt Projection

Weld Bolt

Insulation

Solich, T “Improving Projection Welding Results” Practical Welding Today, Nov-Dec 1997

Solich, T “Improving Projection Welding Results” Practical Welding Today, Nov-Dec 1997

Ideal Microstructure for a Solid Projection Weld

Effect of too Little Upset on Solid Projection Weld

Effect of Excessive Upset on a Solid Projection Weld

Excessive Weld Related Cracking

Crack Propagation in a Solid Projection Weld

Effects of Weld Time and Projection Shape

[Reference: Metals Handbook Volume IV - Welding, Brazing andSoldering, ASM, p.503-524]

Before Welding After Welding Before Welding After Welding

(a) Short Weld Time Full-Width Projection

(b) Correct Weld Time Full-Width Projection

Notch Notch

Sheet

Slight Bulge

PronouncedBulge

Tube

Effects of Weld Time and Projection Shape (CONT.)

[Reference: Metals Handbook Volume IV - Welding, Brazing andSoldering, ASM, p.503-524]

(c) Excessive Weld Time Full-Width Projection

(d) Correct Weld Time Reduced-Width Projection

Before Welding After Welding Before Welding After Welding

Notch Notch

Extensive Bulge

Solich, T “Improving Projection Welding Results” Practical Welding Today, Nov-Dec 1997

Troubleshooting Guide

Burning, discoloration • Increase pressure• Shorten weld time• Add hold time• Reduce heat

Flashing of projections or “spitting of molten metal• Increase Pressure• Shorten Weld time• Increase squeeze time• Reduce heat• Check for dirty or scaly material• Check insulation in locating fixture

Poor, weak or missing welds• Increase welder force • Increase welder KVA capacity• Increase weld time• Increase heat• Reduce electrode pressure