Statistical and metallurgy analysis of welded joint of three DP-270 steels dissimilar in thickness

This study explores the optimization of Resistance Spot Welding (RSW) parameters for joining dissimilar thickness Dual Phase-270 steels. A full factorial design and Taguchi’s method were employed to identify optimal welding parameters maximizing joint strength. Tensile tests and Vickers hardness measurements were conducted to evaluate the mechanical properties of the resulting weld nuggets. Results indicate that experimental design and statistical analysis effectively determine optimal joining parameters. A correlation was found between sheet thickness and weld joint strength, with thicker sheets yielding superior results. Higher thickness variations adversely affect mechanical and metallurgical properties, emphasizing the importance of tailoring RSW parameters for specific thickness combinations. The optimal parameters identified were welding current of 3500 A, welding time of 500 ms, and a paired thickness of 2.68 mm.