Evaluating the TIG welding process mechanically and microstructurally in relation to welding parameters

The exceptional mechanical qualities of super martensitic stainless steel have led to its widespread use in structural components subjected to cyclic loadings. The Tungsten Inert Gas (TIG) welding process, an essential technology for modern industrial fabrication, offers potential improvements in weld quality through precise parameter adjustments. This study investigates the effects of varying TIG welding parameters, specifically welding speed (S), welding current (I), voltage (V), and gas flow rate (GFR). Parameters were explored within the ranges of 50–150 mm/min for welding speed, 10–20 volts for voltage, 90–160 amperes for welding current, and 8–20 l/min for gas flow rate. Using response surface methodology (RSM), we identified optimized values of 120 mm/min for welding speed, 15 volts, 140 amperes, and 15 l/min for gas flow rate, which significantly enhance the strength and quality of welds. Mechanical testing such as tensile and hardness tests along with bead profiles and microstructural characterization were conducted to validate the strength and integrity of the welds under these optimized conditions. The findings suggest that, compared to baseline settings, optimizing both energy use and welding quality not only conserves resources but also improves the durability and performance of welded joints. SEM analysis of AISI 410 S SMSS weldment reveals grain boundaries, 42% ferrite in elongated bands, 44% delta ferrite phase of martensite, and scattered globular Cr 2 C 3 , indicating a complex microstructure with mixed phases.