Experimental Evaluation of Key Welding Process Parameters on the Performance of MIG Welded Mild Steel

The implementation of innovative techniques and sophisticated procedures in welding enhances efficiency and productivity. Automation, particularly robot assisted automation, is crucial in the development of advanced welding systems. In contrast to traditional Gas Metal Arc Welding (GMAW), contemporary methods enable reduced thermal input, maintaining the workpiece and weld areas at relatively lower temperatures. This reduced heat input not only minimizes thermal distortion but also improves weld precision, reduces spatter, and enables the successful joining of mild steel, galvanized sheets, and dissimilar metals, such as steel and aluminium. In this regard, this current research paper proposes to unearth the effect of the three parameters that are attributed to considerable input of metal and influence on the mechanical performance of Metal Inert Gas (MIG) welded mild steel joints, such as current, voltage, and wire feed speed. Weld strength was assessed by mechanical properties such as tensile strength, hardness, and microstructural characteristics. The techniques employed in underpinning the experiments were drawn using a Taguchi L9 orthogonal array and three uses of three-level input parameters. ANOVA results demonstrated that the strongest influence was made by welding current to tensile strength, with the remaining 2 of the 3 factors being voltage and the wire feed rate. Welding voltage, on the contrary, had the highest impact on hardness, and so did the wire feed rate and the current rate. The best parameter conditions of maximum hardness were determined to be at 30 V, 160 A, and 6 m/min, whereas the optimal conditions of maximum tensile strength were 30 V, 170 A, and 2 m/min. The microstructural examination showed the weld zone to have fine grains of ferrite and pearlite, which meant that the metallurgical standard was high. This paper focuses on the importance of optimizing the process to achieve high-quality welds and also highlights the appropriateness of MIG welding for precision and automated welding.