Welding and electrochemical behavior of ferritic AISI 430 and austeno-ferritic UNS 32205 dissimilar welds

Abstract

Stainless steel UNS 32205 and AISI 430 welded by arc welding process with the help of Mo-based austenitic and duplex electrodes. Microstructure studies of the welds revealed the complex microstructure with different solidification mode. The duplex weld showed the ferritic mode of solidification with the presence of various forms of austenite. While Mo-based austenitic weld illustrated ferritic-austenitic mode having ferrite as a cores of the subgrains in the austenite phase. The analysis of X-ray diffraction revealed the existance of carbide phase in the welds due to the presence of more carbon. Electron backscatter diffraction showed strong texture of both welded zone. Higher ferrite content was measured in duplex electrode weld. Higher degree of sensitization was measured in AISI 430 base metal and duplex weld. Higher pitting corrosion and film resistance were measured in duplex base metal and duplex electrode weld. More intergranular corrosion was observed in the heat affected zone of AISI 430.