Effect of Hot-Rolling Deformation on Microstructure and Sliding Wear of High-Chromium Cast Iron

Sandwich-structured composite plates, in which high-chromium cast iron (HCCI) was cladded by low-carbon steel (LCS), were newly prepared by a hot-rolling process at different reduction rates. The effects of hot-rolling deformation on the microstructure and sliding wear behavior of HCCI were investigated. Experimental results revealed that the brittle HCCI core layer exhibited good thermoplastic deformation performance when the sandwich structure was hot-rolled at 1150 °C. The thermomechanical treatment not only caused the fracture of Cr-carbides in HCCI, but also made the long axis of Cr-carbide rods parallel to the wear surface. The high area fraction of Cr-carbides and precipitation of secondary carbides improved the wear performance of HCCI. Both the hot-rolled and heat-treated specimens showed better wear resistance than as-cast iron. However, the wear resistance of the hot-rolled specimens decreased as the cumulative reduction rate increased, which is attributed to the synergistic effect of crack propagation and the high area fraction of carbide cavities.