Patent ID: 8187529
Filing Date: 2012-05-29
Classification: C22C

Abstract:
1. A wear resistant, high chromium white iron with an amount of chromium of 15-27% and of carbon of 2.5-6%, wherein said white iron in an unheat-treated condition has a microstructure including austenite and M 7 C 3 carbides, the white iron containing a martensite promoter being silicon at a level from 0.25 to 3.5% and at least two austenite stabilizers are present, and the combined level of austenite stabilizer is not in excess of about 20%, one of the austenite stabilizers being nickel at a level of from 4 to 12% with at least one other austenite stabilizer selected from the group of manganese, copper and molybdenum at a level of from 4 to 12% for each of manganese, and copper, and an effective equivalent of molybdenum after allowance for a proportion of molybdenum taken up as carbide, and wherein the level of the martensite promoter and the level of the austenite stabilizer are selected so as to achieve a balance between their effects such that the white iron in an unheat-treated condition has a microstructure that is free of martensite at interfaces between the austenite and M 7 C 3 carbides such that the white iron is substantially crack-free.