Crushing and grinding are widely used in mining, mineral processing, cement making, and coal power generation. The mechanical components that contact with materials being processed are working under the conditions of high abrasion and impact. How to reduce the wearing damages and prevent from the cracking failure of the mechanical parts is one of the crucial challenges facing the operations of many industries, involved crushing and grinding processes. Whit cast irons, and specifically high chromium white cast irons, have been developed and deployed worldwide for making mechanical components of crushing and grinding machines due to the combination of high wear resistance and good mechanical strength. The paper is aimed to give an overview on the white cast iron alloys, and particularly high chromium white cast iron alloys, including their classifications, their standard specifications in USA, China and Australia, their main usages and the new developments.

High chromium white cast irons (HCWCI) are widely used as abrasion resistant materials in cement manufacturing, mineral processing and slurry pumping industries. Their high resistance to wear in these demanding situations stems from the presence of hard eutectic (Cr, Fe)7C3 carbides in their microstructures. In this context, the properties of hypoeutectic iron of HCWCI containing 25 wt. %Cr-2.5 wt. %C were investigated after destabilisation heat treatments, cooling (slow and fast cooling) to ambient temperatures, their influence on the microstructure was investigated. For characterization of the hypoeutectic iron of HCWCI, several experimental tests were performed using the following laboratory equipment: light optical microscope, scanning electron microscope. The amount of retained austenite also depends on the alloying additions in the melt during melting processes, destabilisation temperatures, soaking time and the cooling rates during heat treatment processes.

The properties of hypoeutectic iron of HCWCI containing 25 wt. %Cr-2.5 wt. %C were investigated after destabilisation heat treatments, cooling (slow and fast cooling) to ambient temperatures, their influence on the structure and hardness was investigated using X-ray diffraction (XRD), element distribution analysis and hardness tests. The experimental results show that appropriate heat treatments contribute to a significant improvement on the mechanical properties of selected alloy of HCWCI. The results are discussed in terms of the change in austenite phase at the different destabilisation heat treatment temperatures.