A METHOD OF HEAT TREATING HIGH CHROMIUM CAST FERROUS-BASED ALLOYS AND A WEARING ELEMENT FORMED OF A HIGH CHROMIUM CAST FERROUS BASED ALLOY

摘要

A method of heat treating a component formed of an alloy consisting of 11-28 wt% chromium, 1-3.6 wt% carbon and at least 0.2 wt% molybdenum and/or at least 0.6 wt% tungsten, the remainder (apart from any incidental ingredients and impurities) being iron, comprising the steps of:- a) holding said component at a temperature between the solidus temperature of the alloy and 1050 DEG C for a period of time not exceeding 3 days in a non-oxidising atmosphere or vacuum so as to produce a partially spheroidised hard carbide phase in an austenitic matrix throughout the component, and b) quenching the component at a mean rate of from 40 DEG C/min to 3 DEG C/min in the critical temperature range in order to retain the austenitic matrix.