Wear mechanism and chemical composition optimization of complex-alloyed cast iron with spheroidal vanadium carbide under conditions of abrasive erosion

Abstract

Using full factorial design in experiment 3², the contents of vanadium and chromium in heattreated V–Cr–Mn–Ni cast irons with spheroidal vanadium carbide have been optimized with regard to the conditions of quartz sand erosion. It has been found that, in the case of bulk quenching from 760°C (or in combination with a subsequent plasma surface hardening), the maximum wear resistance of cast iron is achieved at 5.0% V and 2.0–4.5% Cr and, in the case of bulk quenching from 840°C followed by cryogenic treatment (–196°C), at 5.0% V and 7.0–9.0% Cr. It has been shown that the wear mechanism of the investigated alloys consists of the repeated deformation (indentation) of the matrix accompanied with spalling of spheroidal carbides and with chipping of eutectic carbides. Spheroidal vanadium carbides provide an effective protection of dendrites regions against erosion due to their uniform distribution in the bulk of the alloys.