Microstructure and Mechanical Properties of 10CrNi3MoV Steel-SS304L Composite Bimetallic Plates Butt Joint by Shielded Metal Arc Welding

In the present study, composite bimetallic plates of 10CrNi3MoV steel—304L stainless steel were butt welded by shielded metal arc welding (SMAW). A transition layer was designed to compensate for the dilution of Cr and Ni in stainless steel layer during the welding of dissimilar metals. From the results, it was seen that the lowest hardness of fusion weld was located in transition layer, followed by 304L stainless steel side, and the highest hardness occurred at 10CrNi3MoV steel area. The minimum hardness was related to high Cr and Ni in transition layer welded by E309L welding rod, and a uniform dendritic austenite structure was formed in the fusion weld. The formation of high-hardness carbides and vanadium-containing phases enhanced the hardness of the fusion weld. Butt welded joints had excellent tensile strength and toughness. The maximum tensile strength of the joint was about 694 MPa, and the tensile specimens fractured in ductile at matrix of the bimetallic plates. The impact energy of the weld joint was about 98 J at − 20 °C. When the number of loading cycles was set to 2 × 106 times, the maximum load limit of the bimetallic plate welded joint in 10CrNi3MoV steel was between 600 MPa and 625 MPa.