solid projections (solid state welds). solid projections lesson objectives when you finish this...
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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