Investigation on Weld Bead Geometry of AISI 201LN in GMAW-Cold Metal Transfer (CMT) Process

Abstract

The welding of thin sheet of austenitic stainless steel (SS201LN) is a challenging task due to distortion and high heat input associated during tungsten inert gas (TIG) process. A robotic cold metal transfer (CMT) process is the modified version of gas metal arc welding (GMAW) process in which the heat input is reduced due to controlled wire feeding and higher welding speed. In this work, GMAW (with CMT) process of AISI 201LN stainless steel plate is performed using Box–Behnken design (BBD). Wire feed rate (WFR), welding speed (S), and nozzle to work distance (NTD) are considered weld parameters to investigate process characteristics of weld bead viz., penetration (P), width (W), and reinforcement (R). Predictive models are developed using response surface methodology (RSM) and model validation shows an average error % of 2.61 for penetration. ANOVA analysis shows that WFR and welding speed are the most influencing factors, whereas NTD having the least influence in determining penetration. The parametric optimization of all responses simultaneously is carried out using desirability analysis (DA) obtaining composite desirability of 0.7216 mm/min.