FACTORS INFLUENCING THE MECHANICAL PROPERTIES OF HIGH CHROMIUM WHITE CAST IRON

Abstract

The high chromium white cast iron (HCWCI) has been in use for decades and is expected to remain popular due to its superb wear resistance. This wear resistant material is recognized for its superior hardness, toughness, and corrosion resistance. It is widely used in industries such as mining, cement, and power generation, where high abrasion and impact resistance are essential. The studies in this paper were conducted on an alloy containing 24.48% chromium, 2.66% carbon 1.32% molybdenum, 1.6% nickel, 0.99% silicon and 0.96% manganese. Mechanical and microstructural characterization was carried out on both as-cast samples and samples subjected to appropriate heat treatment (quenching 1000 ^oC/2h air cooling, quenching followed by tempering at 250^oC/3h and quenching  to -196^oC in liquid nitrogen). Mechanical characterization involved measuring Vickers hardness and assessing toughness using Sarpi's pendulum. Hardness and toughness results of samples are correlated with the obtained microstructure. The applied heat treatment led to an increase in the hardness values, while toughness values remained largely unchanged, which is a consequence of the unmodified forms of the existing carbides. Various types of carbides (M₃C and M₇C₃ type, but also for this alloy typical Mo₂C carbide) can be observed through etching with Murakam's reagent.