OPTIMIZATION OF MANUAL METAL ARC WELDING PARAMETERS FOR ULTIMATE TENSILE STRENGTH OF MILD STEEL SAE 1020 AND STAINLESS STEEL SS-303 USING TAGUCHI METHOD

Manual Metal Arc Welding (MMAW) is one of the most widely used welding processes in developing countries due to its simplicity, low cost, and versatility. Weld quality in MMAW is strongly influenced by process parameters such as welding current, welding speed, root gap, and electrode angle. This work investigates the optimization of MMAW parameters to maximize the Ultimate Tensile Strength (UTS) of dissimilar welded joints of Mild Steel SAE 1020 and Stainless Steel SS-303. Taguchi’s Design of Experiments (DOE) methodology using an L9 orthogonal array was employed to minimize experimental trials. Signal-to-Noise (S/N) ratio analysis and Analysis of Variance (ANOVA) were used to identify the most influential parameters. The results indicate that welding speed and welding current are the most significant factors affecting UTS. The optimal combination of parameters was found to be welding current 120 A, welding speed 60 cm/min, root gap 1.5 mm, and electrode angle 60°. A multiple linear regression model was developed to predict UTS, and confirmation tests validated the experimental findings with acceptable error margins.