Effects of Carbon and Tungsten on Mechanical and Hot Wear Properties of Multi-component White Cast Irons

Abstract

  Multi-component white cast irons containing multiple carbide-forming elements such as Cr, Mo, W and V have been widely popularized as roll materials for hot rolling mills because of their excellent wear resistance. In this research, effects of carbon (C) and tungsten (W) contents on mechanical properties and hot wear resistance were investigated using Fe-5%Cr-5%Mo-5%V-5%Co-W-C (mass%) cast alloys. Cast irons with M₂C eutectic carbides and martensitic matrix were obtained in the range of C=1.5 to 2.5mass% and W=0 to 7.5mass%. Martensite matrixes showed over 600HV in micro-hardness, and the change in micro-hardness was closely related to that of macro-hardness. Tensile strength, compressive 0.2% proof strength and fracture toughness were high in cast irons with high hardness, but they decreased in 3mass%C cast irons due to the existence of large amount of carbides. Hot wear resistance was better in cast irons with higher hardness and higher fracture toughness.