Experimental Study on the Influence of Heat Treatment on the Structure and Properties of Alloyed Cast Iron with 15% Cr

Abstract

In the current study, the influence of heat treatment on the microstructure, abrasive wear and mechanical properties of high chromium cast iron 3% Mo was investigated. After hardening heat treatment at of the alloy under investigation at 950 o C, the as cast austenitic structure transformed mostly to martensitic matrix containing fine precipitates of secondary carbides and surrounded by a network of M7C3 carbides. The holding time at the optimum austenitizing temperature for a specific alloy should be sufficient to ensure the complete precipitation of secondary carbide through all structure of specimen. Experimental results showed that the higher wear resistance and hardness was obtained after hardening at 950 o C for 120 minutes holding time, followed by air cooling. Increasing sliding wear distances at the load of 30N decreased the abrasive wear resistance of the investigated alloy after hardening and tempering heat treatments. Tempering heat treatment after air hardening of the investigated alloy at 400 o C gave little changes in both hardness and abrasive wear resistance, but tempering treatment at 500 o C resulted in marked improvements in these properties.