Optimization of Resistance Spot Welding Parameters and Shielding Atmosphere Effects on the Mechanical Performance of AISI 201 Stainless Steel

Abstract

Attaining uniform weld quality in the resistance spot welding (RSW) of AISI 201 stainless steel remains challenging due to the complex interdependence of process parameters and the limited understanding of shielding atmosphere effects on this lean austenitic grade. This study integrates Taguchi optimization, analysis of variance (ANOVA), and complementary trend surface visualization to evaluate the effects of welding time, current, electrode pressure, and shielding atmosphere. An L27 orthogonal array was employed, with welding current identified as the dominant parameter for both tensile strength and hardness while nitrogen shielding exhibited a significantly greater influence on hardness than on tensile force, attributable to interstitial solid solution strengthening. The optimal conditions yielded a maximum tensile force of 12.2 kN and a hardness of 353 HV, with prediction errors below 1.5% for tensile force and below 0.5% for hardness. Trend surface visualization further revealed significant current–pressure interactions governing weld quality. These findings provide a validated optimization framework for the industrial RSW of AISI 201, with direct implications for automotive and structural manufacturing.