Effects of laser power on the microstructure, mechanical properties, and corrosion resistance of welded joints in dissimilar laser welding of 05Cr17Ni4Cu4Nb stainless steel and HR-2 stainless steel

The dissimilar 05Cr17Ni4Cu4Nb stainless steel and HR-2 stainless steel were welded without groove and wire filling by laser deep fusion welding. The microstructure characteristics, mechanical properties, and Cr_ep on the corrosion resistance of the joints with different laser power were investigated in detail. The weld metals (WM) of the dissimilar joints illustrated ferritic-austenitic mode of solidification with different welding processes. The joints with lower laser powers present fine grain and excellent mechanical properties. The tensile specimens failed at the HR-2 side and massive dimples were distributed in the fracture surface, indicating typical ductile fracture mode of the joints. The EDS results of the WM show that the white granular carbides are mainly NbC and M₂₃C₆ (M denotes Cr and Fe elements) precipitated phases. The results of electrochemical test show that the best corrosion resistance of the joints is achieved with higher Cr_ep in the WM.