Welding

Presented by Robert Pelton & Tyson Baker

MeEn 372

December 10, 2001

Outline

• Applications• Equipment/Processes• Specifications• Joint types• Weld Joints• Stress Concentrations• Stress Calculations

Applications

Types

• MIG (Metal Inert Gas)

• TIG (Tungsten Inert Gas)

• SAW (Submerged Arc Welding)

• SMAW (Shielded Metal Arc Welding)

Equipment

Fundamentals

• Electrode

• Filler material– Solid

– Cored

• Shielding gas – Argon

– Nitrogen

– Helium

Specifications

• MIG – Capacity: 0.020 to 0.250 in

– consumable electrode

– Weld materials: Carbon steels, low alloy steels, stainless steels, most aluminum alloys, zinc based copper alloys

• TIG – Capacity: 0.005 to 0.250 in

– Non-consumable tungsten electrode

Considerations

• Accessibility

• Distortion

• Heat

• Spatter

• Surface finish

• Automation

Problems

Causes

• Cracks• Cavities (Porosity)• Rough Dirty Bead• Incomplete fusion

Good WeldSurface Porosity

Joint Types

Stress Concentration

Stress Calculations

Weld strength

Web Sites

• http://www.aws.org/ American Welding Society

• http://www.ewi.org/ Welding and Joining Information Network

• http://www.adtdl.army.mil/cgi-bin/atdl.dll/tc/9-237/toc.htm Welding Theory and Application, Department of the Army, Washington, DC, 7 May 1993

• http://www.lincolnwelding.com Lincon Electric (welding supply co.)

• http://www.weldingengineer.com/ Welding Procedures and Welding Techniques

References

• Todd, Robert H., et al., Manufacturing Processes Reference Guide, Industrial Press Inc. New York, 1994.

• http://www.efunda.com/processes/metal_processing/welding_inertgas.cfm

Questions?