Optimization of process parameters for plasma arc welding of austenitic stainless steel (304L) with low carbon steel (A-36)

This research aims to optimize the process parameters of plasma arc welding for welding of dissimilar metals: austenitic stainless steel SS-304L and low carbon steel A-36. It investigates the effect of welding current and welding speed on the quality of the welded joints. The quality characteristics like bead geometry, microstructure, hardness, ferrite measurement and tensile test are considered for qualification of the welded samples. Welded specimens were prepared both with and without filler material. These specimens were mechanically tested and analyzed using metallographic techniques. Based on the results, suitable welding parameters were found to be 45A and 2mm/s for samples prepared with and without filler wire. An all-martensitic weld zone structure was obtained for direct fusion. However, a complex heterogeneous microstructure was obtained by using austenitic stainless steel filler wire E 309L. Hardness of directly fused sample was observed to be significantly higher compared to filler wire sample.