Fabrication of a Composite Material of High-Chromium Cast Iron Dispersed in Low-Carbon Steel by Hot-Rolling Process

To obtain a compatible material with good wear resistance (WR) and toughness, a composite material with high-chromium cast iron (HCCI) dispersed in low-carbon steel (LCS) is prepared through multilayer hot rolling. The microstructure and mechanical properties of the composite are investigated. The macrostructure of the composite material reveals that the HCCI layers are necked, fractured, and dispersed in LCS after hot rolling. The two materials combine well without unconnected areas and macrovoids on the interface; however, broken oxides are observed at the interface. Decarburization occurs at the LCS side near the interface and a 15-20 mu m-wide ferrite zone is formed at the LCS side. Fe, Cr, Mn, and C elements diffuse at the interface. A pearlite band is formed at the interface, and the thickness of the diffusion is about 2-4 mu m. Due to the addition of ductile LCS, the impact toughness of the composite material is about 2.5 times higher than that of the as-cast HCCI, whereas the WR of the composite material is lower than that of HCCI (about 16%). The dispersed HCCI in the composite produces a shadow effect during the sliding wear, which provides protection and support for LCS.

Automated summary

A composite material consisting of high-chromium cast iron (HCCI) dispersed in low-carbon steel (LCS) was prepared through multilayer hot rolling to achieve good wear resistance and toughness. The microstructure and mechanical properties of the composite were investigated, revealing a well-combined interface with broken oxides and decarburization at the LCS side. The impact toughness of the composite material was significantly higher than that of the as-cast HCCI due to the addition of ductile LCS, but the wear resistance was slightly lower than that of HCCI.