Microstructures and intergranular corrosion resistances of hot-rolled austenitic stainless steel clad plates

In this study, two stainless steel clad plates (STS 316L/A516-70N and STS 304L/A516-70N) were fabricated without Ni interlayers by hot rolling and normalizing under the same conditions, and their microstructures and intergranular corrosion resistances were comparatively evaluated. Although a similar amount of C diffused from carbon steel to stainless steel during clad fabrication, the thickness of the grain-boundary carburized layer was thinner in STS 316L due to Mo atoms segregated at the grain boundaries. The stainless steel parts of both clad plates had carbides even at their free surfaces and STS 304L also had some amount of δ ferrite. Nevertheless, the corrosion resistance of the free surfaces of both stainless steels was not undermined.