Global Patent Index - EP 0178894 A3

EP 0178894 A3 19870624 - A METHOD OF HEAT TREATING HIGH CHROMIUM CAST FERROUS-BASED ALLOYS AND A WEARING ELEMENT FORMED OF A HIGH CHROMIUM CAST FERROUS BASED ALLOY

Title (en)

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

Publication

EP 0178894 A3 19870624 (EN)

Application

EP 85307389 A 19851015

Priority

GB 8426222 A 19841017

Abstract (en)

[origin: EP0178894A2] A method of heat treating a component formed of a high-chromium cast ferrous-based alloy consisting of 11-28 wt% chromium, 1 - 3.6 wt% carbon and at least 0.2 wt% molybden um and/or at least 0.6 wt% tungsten, the remainder (apart from any incidental ingredients and impurities) being iron, said method 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. Before heat treament, carbon and chromium form a hard sharp, angular carbide phase and the molybdenum and/or tungsten serves to increase the rate of change in the morphology of the carbidge phase during heat treatment from sharp angularity to a partly spheroidised morphology.

IPC 1-7

C21D 5/04

IPC 8 full level

C21D 6/00 (2006.01); C22C 37/06 (2006.01)

CPC (source: EP)

C21D 6/002 (2013.01); C22C 37/06 (2013.01)

Citation (search report)

Designated contracting state (EPC)

AT BE CH DE FR GB IT LI LU NL SE

DOCDB simple family (publication)

EP 0178894 A2 19860423; EP 0178894 A3 19870624; GB 2167438 A 19860529; GB 2167438 B 19881123; GB 8525382 D0 19851120

DOCDB simple family (application)

EP 85307389 A 19851015; GB 8525382 A 19851015