Influence of The Match between Weathering Steel Metal and Welding Wire on Stress Corrosion Resistance of Welded Joints

Three kinds of welded joints for railway bogie were prepared by welding S355J2W weathering steel and SMA490BW weathering steel matched up with CHW-55CNH and G424M21Z wires respectively. The microstructure, electrochemical performance and stress corrosion resistance for the three kinds of welded joints were studied by optical microscopy, electrochemical test and slow strain rate test (SSRT). The results show that the welded joint of S355J2W weathering steel and G424M21Z wire was a high matching joint, the strength gap between base metal and weld seam was large, which could cause stress concentration easily in the joint. The joint had a large stress corrosion tendency and the largest electrochemical corrosion tendency. The welded joint of S355J2W weathering steel and CHW-55CNH wire was also a high matching joint, which had a low stress corrosion tendency. The welded joint of SMA490BW weathering steel and CHW-55CNH wire was a low matching joint, the strength of base metal and weld zone was equal, the stress concentration in the joint was small, and the joint had a low stress corrosion tendency and the lowest electrochemical corrosion tendency.