Optimization of P-GMAW parameters using Grey relational analysis and Taguchi method

The aim of this study is to optimize the process parameters for Pulsed gas metal arc welding (P-GMAW) of dissimilar metal joints involving stainless steel 304 and low carbon steel. The research examined at a square butt joint between 2mm thick sheets welded using a P-GMAW process with 80 % Ar + 20% CO2 as shielding gas and deoxidizer wire of grade AWS ER70S-6 as filler material. The L9 Taguchi array was used for optimization, with the required quality characteristics being ultimate tensile strength and mass deposition rate of the resulting weld joint. Grey relational analysis and Taguchi optimization of P-GMAW process parameters such as weld current, wire feed rate and welding speed is performed at three levels. ANOVA was used to assess the impact of each factor. The best set of parameters was identified, were wire feed rate and weld current being the most significant variable and weld speed being the least influential. Bending distortion and buckling are observed on the weld plate and detailed analysis of distortion will be done in future.