Microstructure and Mechanical Properties of SA508 Gr.3 Steel Cladded by GMAW using 309L and 308L Wires

In this study, the microstructure and mechanical properties of GMAW cladded stainless steel layer on SA508 Gr.3 base steel were investigated. In SA508 base steel, black strip regions were observed with a higher concentration of alloying elements and a greater precipitation of carbides compared to the normal region, forming microstructure with a higher fraction of martensite. The fusion line (FL) between cladding layer and SA508 base steel was formed as a martensite layer, and unmixed region was observed near the FL. The 309L and 308L cladding layers exhibited complex solidification microstructures with cellular and vermicular morphologies. The microstructure was observed using optical microscopy (OM), scanning electron microscopy (SEM), and electron backscattered diffraction (EBSD) analyses. Finally, the hardness distribution across the FL was evaluated and the correlation between microstructure and hardness was then analyzed.