Optimizing Abrasion Wear Resistance and Impact Toughness of White Iron

Wear is a persistent service condition in many engineering applications. The demand for increased service life, even under severe conditions, has generated an interest in improving the quality of these wear-resistant alloys. For decades white cast irons have been the work horse of wear protection in the mining and cement industry because of their high hardness, high strength, net shape castability, high wear resistance and relatively low cost. However, chromium-molybdenum white cast iron is still a kind of brittle material. It can¿t meet the demand of severe working conditions, such as high impact wear conditions. Therefore, this study is aimed at optimizing impact toughness and abrasion wear resistance of 15%Cr-2%Mo hypo- and hypereutectic abrasion-resistant white irons. To achieve this goal, four routes were followed: (i) dynamic solidification, (ii) alloying with Nb, (iii) combined action of Nb-alloying and dynamic solidification, and (iv) heat treatment. The relationship between impact toughness and abrasion wear resistance via microstructure control was established.