Investigation of Weld Bead Characteristics and Optimization of GMAW of Nitrogen Strengthened Austenitic Stainless Steel (AISI 201Gr)

Abstract

Austenitic stainless steels are widely used in fabrication industries for its enhanced mechanical properties and excellent corrosion resistance. In this work gas metal arc welding (GMAW) on AISI 201Gr stainless steel plate is performed using Box–Behnken design (BBD). Wire feed rate (F), voltage (V), nozzle to plate distance (NTD) and welding speed (S) are considered as weld parameters to investigate four process characteristics viz., penetration (P), width (W), reinforcement (R), weld penetration shape factor (WPSF), weld reinforcement form factor (WRFF). Predictive models are developed using response surface methodology (RSM) and model validation shows an average error % of 3.66 being maximum for penetration. The penetration and bead width are increasing with increase in wire feed rate. ANOVA analysis shows that F, voltage and NTD are the most influencing factors in determining penetration. The parametric optimization of all response simultaneously is carried out using desirability analysis (DA) obtaining composite desirability of 0.6631.