Optimization of TIG Welding Parameters for AISI 304 Stainless Steel Using Conventional and Hybrid Tungsten Electrodes: Mechanical Performance, Radiographic Evaluation, Hardness Distribution, and Numerical Simulation

Abstract

TIG welding is widely used for joining austenitic stainless steels because of the clean, controlled welds it produces with minimal contamination. In this work, we examined how nine different tungsten electrode types affect the weld quality of 3 mm AISI 304 stainless steel plates under direct-current conditions at three current settings: 60 A, 70 A, and 80 A, with argon shielding throughout.

Weld quality was evaluated through tensile and bend testing, radiographic examination, microhardness profiling, and finite-element simulation. The results show a clear performance advantage for hybrid electrodes over conventional ones. Among all tested configurations, the MX2 hybrid electrode at 70 A gave the highest tensile strength,around 772 Mpa-with elongation values above 100%. Radiographic inspection of these welds showed very few internal defects. Based on our findings, welding currents in the 60–70 A range appear best suited for this material and thickness.