Dissimilar welding of AISI 201 and 202 low nickel stainless steels by GTA and PA welding processes

This paper presents the results of dissimilar joining techniques for AISI 201 and 202 low nickel austenitic stainless steels. These were welded by Gas Tungsten Arc Welding (GTAW) and Plasma Arc Welding (PAW). The tests were performed to examine the weld bead shapes, microstructure, mechanical properties and corrosive behavior of the weld metals with different welding processes. The weld bead shape by GTAW was larger than that performed by PAW. The microstructure of the weld metal produced by GTAW contained more delta ferrite in the austenite matrix than the weld metal produced by PAW. The volume of hardness in welds produced by PAW higher than the GTAW process same with the ultimate tensile strength and percentage elongation welds produced by PAW higher than the GTAW process. According to the potentiodynamic polarization test results, pitting corrosion resistance of the weld produced by PAW was higher than the weld produced by GTAW. Both weld metals showed the pitted area adjacent to the phase boundary between austenite and delta ferrite in the mixed microstructure. Based on the present work, it was concluded that PAW was the more suitable welding procedure for joining dissimilar 201 and 202 austenitic stainless steels.