Fabrication of high chromium cast iron/low carbon steel composite material by cast and hot rolling process

A sandwich-structured composite blank containing a high chromium cast iron (HCCI) and low carbon steel (LCS) claddings was successfully fabricated by casting and hot rolling, and then a series of quenching and tempering treatments were employed. The evolution of microstructures and microhardness of as-cast, hot-rolled and heat-treated specimens were investigated. The microstructures of hot-rolled HCCI are refined and significant variations of carbides are observed. A perfect metallurgical bonding between HCCI and LCS is revealed by the continuous distributions of alloy elements. The microhardness of hot-rolled HCCI after quenching and tempering is found to be close to that of as-cast one. The hardness of HCCI can reach up to HV 750 or above after oil quenching. The hardness of HCCI reduced to HV 600–750 after tempering due to the tempering of martensite.