Microstructural Characterization of a Stainless-Cladded Carbon Steel

In stainless-cladded carbon steels, microstructural changes, due to carbon and other elements diffusion, take place at the interface strictly depending on the temperature values reached during the production process. The microstructural changes at the interface in a carbon steel (ASTM A 515 Gr 60) cladded by hot rolling with an AISI 304L steel was examined in this paper. Carbide precipitation, due to carbon diffusion towards the austenitic steel, was observed by optical and scanning electron microscopy (SEM); substitutional elements distribution was studied by energy dispersive spectroscopy (EDS); mechanical properties at the bimetallic interface were tested by Vickers microhardness measurements. These measurements showed a hardened region at the stainless side near the interface: here, during production process, Cr carbide precipitation occurs at the austenitic grain boundaries, with a partial local Cr depletion