Optimization of Resistance Spot Welding Parameters in Uncoated Cold-Rolled Steel by Using Taguchi Method

Objective: This study aims to evaluate the effects of spot-welding parameters specifically welding current, electrode force, and welding time on the tensile shear strength of 1.2 mm uncoated cold-rolled steel. The primary objective is to optimize these parameters to produce robust and reliable welded connections, especially in applications exposed to variable tensile-shear stresses. Method: The research utilized an L9 Taguchi orthogonal array to systematically randomize and analyze the effects of different process parameter configurations. The signal-to-noise (S/N) ratio was employed to identify the optimal welding parameters that maximize tensile shear strength. Additionally, Analysis of Variance (ANOVA) was used to assess the significance of each parameter's contribution to the tensile shear strength, providing a deeper understanding of the critical factors influencing weld quality. Findings: The optimal spot-welding parameters identified in this study are an electrode force of 2.1 kN, a welding time of 10 cycles, and a welding current of 6 kA. Among these parameters, electrode force emerged as the most critical factor influencing tensile shear strength, as demonstrated by ANOVA analysis. This finding highlights the importance of precise control over electrode force in achieving well-welded connections. Novelty: This research combines the Taguchi method with ANOVA to comprehensively examine and optimize spot-welding parameters for cold-rolled steel. By identifying electrode force as the most significant determinant of tensile shear strength, the study provides valuable insights into the optimization of welding processes. These findings are particularly relevant for industries such as automotive and manufacturing, where welded joints are subjected to rigorous stress conditions. Keywords: Taguchi Method, Optimization, Resistance, Spot Welding, Electrode Force, ANOVA, Tensile Strength