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Solid Projections PowerPoint PPT Presentation


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Solid Projections. (Solid State Welds). Solid Projections. Learning Activities View Slides; Read Notes, Listen to lecture Do on-line workbook. Lesson Objectives When you finish this lesson you will understand: Solid State Weld as applied to projections and studs

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Solid Projections

(Solid State Welds)


Solid Projections

  • Learning Activities

  • View Slides;

  • Read Notes,

  • Listen to lecture

  • Do on-line workbook

  • Lesson Objectives

  • When you finish this lesson you will understand:

  • Solid State Weld as applied to projections and studs

  • Applications of Solid Projection Welds

Keywords

Solid Projection Weld, Solid State Weld, Swelling


Resistance welder Manufacturers Association Bulletin # 35


Resistance welder Manufacturers Association Bulletin # 35


Heat Flows

Into Cold Plate

Thicker Plate = More Heat Loss

Current Flow Heats Pipe

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


Short Weld Time

Low Weld Force

Proper Weld Conditions

Note Swelling of OD

Slight Swelling of ID

Excessive Weld Time

Excessive Weld Force

Proper Restricted Width Weld

No Swelling of OD

Resistance welder Manufacturers Association Bulletin # 35


Photomicrographs

Of Full Width

Solid Projection

Welds

Resistance welder Manufacturers Association Bulletin # 35


Photomicrographs

Of Restricted Width

Solid Projection

Welds

Resistance welder Manufacturers Association Bulletin # 35


Parameters

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

Resistance welder Manufacturers Association Bulletin # 35


Excessive Swelling

Weld Force

Acceptable Swelling

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

Resistance welder Manufacturers Association Bulletin # 35


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

Correct Projection Incorrect Projection

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


Application for Welding Studs or Bushing into Metal Opening

Start of Welding Finish of Welding

Electrode

Electrode

Weld

Electrode

Electrode

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


Application of Annular Projections

Weld

(a) (b)

(c) (d)

Threaded Boss

Shoulder Stud

Weld

Tight Joint

Relief for

Upset Metal

to Fill in

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


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

Insulated Steel Pin with

Shoulder

Electrode

Weld

Electrode

Electrode

Electrode

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


Recessed Electrode for Locating Nut for Welding

Electrode

Electrode

Electrode

Electrode

Weld

Weld

Nut

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


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

Insulation

Bolt Retainer

Projection

Weld Bolt

Projection

Weld Bolt

Flat Spring

Sheet Metal

Insulation

Drill Hole in Electrode

to Clear Threads

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


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

Tube

Pronounced

Bulge

Slight Bulge

Notch

Notch

Sheet

Before Welding After Welding Before Welding After Welding

(a) Short Weld Time

Full-Width Projection

(b) Correct Weld Time

Full-Width Projection

[Reference: Metals Handbook Volume IV - Welding, Brazing and

Soldering, ASM, p.503-524]


Effects of Weld Time and Projection Shape (CONT.)

Extensive Bulge

Notch

Notch

Before Welding After Welding Before Welding After Welding

(c) Excessive Weld Time

Full-Width Projection

(d) Correct Weld Time

Reduced-Width Projection

[Reference: Metals Handbook Volume IV - Welding, Brazing and

Soldering, ASM, p.503-524]


Troubleshooting Guide

  • 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

  • Burning, discoloration

  • Increase pressure

  • Shorten weld time

  • Add hold time

  • Reduce heat

  • Poor, weak or missing welds

  • Increase welder force

  • Increase welder KVA capacity

  • Increase weld time

  • Increase heat

  • Reduce electrode pressure

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


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