Mechanical and Microstructure Analysis of Pulsed Current Gas Tungsten Arc Welded Dissimilar Duplex UNS32205 and Austenitic AISI 321 Stainless Steel Joints

Abstract

Dissimilar metal welding (DMW) gives a distinctive and complex process because each zone in the different welding area has unique structures and characteristics. The customized weld zone has a unique structure and may have a heating effect on weld metal properties. DMW is used in aerospace, marine, oil refineries, petrochemical industries, power plants including nuclear and other engineering applications due to economic considerations and offered lightweight in design. This paper's main objective is to investigate the microstructure evolution and impact strength of a joint Austenitic AISI 321 plates and Duplex UNS32205 stainless steel welded using pulsed current GTAW (PCGTAW). The base plates were joined by ER2209 filler metal and the microstructure of base and weld metal zones was observed. The selected filler metal was a duplex in nature and contains equal ratio of austenite and ferrite phase in the different weld metal zones of UNS32205 and AISI 321 weldments. The fractography studies of dissimilar joints UNS32205 and AISI 321 were done and investigated through scanning electron microscopic (SEM). Pipe joints in oil and gas and petrochemical industries make use of bimetallic combinations of different stainless steels.