EFFECT OF MIG WELDING PROCESS ON THE MECHANICAL CHARACTERISTICS OF COLD ROLLED SHEETS

Welding is one of the most commonly used techniques which can give strength comparable with the parent material. The welded sections are more prone to fatigue failures. In this study, the responses of welded structures using MIG process were investigated. Experiment was conducted on butt welded joints with square edge preparation of different combinations of current, welding speed. Tensile test, micro hardness and penetration were conducted on the specimen and the results were tabulated. Welded joints contain metallurgical and compositional differences result from welding process. This effects change in mechanical properties. Tension test is performed to evaluate the breaking strength of the metal. Hardness test is performed at different zones of welded specimens to investigate the reason for the behaviour of weldment. Microstructure of the weld is examined for the weld bead quality. Most of the welded structures are subjected to fluctuating loads over their lifetimes. In designing the welded joints to sustain changing loads over their lifetime these parameters are useful in improving the fatigue life of the structures using proper fatigue improvement techniques for weld.