PROPERTIES OF HIGH-CHROMIUM CAST IRON/LOW-CARBON STEEL BIMETAL FABRICATED BY HOT-ROLLING

A bimetal composite plate including a high-chromium cast iron (HCCI) and low-carbon steel (LCS) cladding was fabricated with hot-rolling bonding in the form of a sandwich structure. In this work, the microstructure and mechanical properties of the bimetal composite were analyzed. Experimental results showed that the brittle HCCI layer achieved good thermoplastic deformation under the action of carbon-steel cladding. After hot rolling, the two metals were well bonded due to mechanical and metallurgical bonding, showing an excellent joint. C atoms diffused uphill the interface. A decarburization area was formed near the LCS side and a fine pearlite diffusion band with a thickness of about 2–3 µm was formed on the bonding interface. The tensile strength of the bimetal composite was 249.5 MPa, and a cleavage fracture appeared on the HCCI side. Interfacial delamination cracks and tunnel cracks of the HCCI were observed in the bimetal composite during a bending test.