Minimization of Weld Defects in Mig and Tig Welding

Abstract

Our project work done for minimizing the welding defects that occur during MIG welding at brake unit in Brakes India Ltd. Welding is the process of joining two similar or dissimilar metals permanently, where MIG welding uses inert gas for shielding and consumable metal for joining two metals. In Brake unit, the welding is performed for joining the web with the rim to form brake shoe. This welding should be very strong so as to resist the distortion due to shear force under dynamic condition. To eradicate frequent occurrences of defects such as blow hole, pin blow hole and start weld. Some of the TQM tools such as cause and effect diagram, Pareto chart, 4 M Methodology and why-why analysis are used to identify the root cause. Hence remedial action taken such as liner cleaning, nozzle cleaning, stopper at the machine bed and tensionner at the feeding unit, helps in reducing the rework rate from 5% to 3%.