Fabrication of High Chromium Cast Iron/Hadfield Steel Composite Materials by the Hot Rolling Process

Bimetal composite blanks were successfully prepared from high chromium cast iron (HCCI) and Hadfield steel by the hot-rolling process. The macrostructure and microstructure of the composite were investigated. After hot-rolling formation, the hard HCCI layers were fractured and embedded in ductile Hadfield steel, forming a three-dimensional composite structure. The two metals were fused and no defects such as interface cracks or unbonded areas were found. A metallurgical bonding between Hadfield steel and HCCI was revealed. The kernel average misorientation (KAM) value of the Hadfield steel layer was low, while the HCCI layer showed a larger green area. It indicated that the HCCI layer had high strain energy and high dislocation density. The bonding process of two metals includes three stages: physical contact, physico-chemical bonding and mutual diffusion.