Influence of Heat Treatment on Erosive Wear Resistance of High Cr Cast Irons

This study examines hypoeutectic 24%Cr cast iron and eutectic 27%Cr cast iron that have the same Cr/C ratio to investigate the relationship between wear resistance and microstructure of as-cast and heat-treated materials under harsh erosion test conditions. Microstructural observation revealed that unlike 27%Cr cast iron, part of the matrix of 24%Cr cast iron formed as lamellar pearlite during cooling after solidification. For the annealing condition, the matrix of both cast irons completely transformed to a granular pearlite. When quenching was performed at two temperatures, the amount of retained austenite increased at the higher temperature. From the results of the wear behavior and surface hardening of both cast irons, it was found that the effect of matrix structure on wear resistance is more significant than that of eutectic carbides. The wear rate of hypoeutectic and eutectic high Cr cast irons depends on the degree of work hardening.