Manufacturing process for ring-shaped parts

Abstract

The present invention relates to a manufacturing process for ring-shaped parts having high wear resistance and mechanical strength. Raw material powder containing (weight %) C at 0.4-0.9%, Ni at 1.5-4.0%, Mo 0.2-0.6%, and a remainder consisting of Fe and unavoidable impurities, is compacted and shaped, thereafter sintered and forged; obtained sintered body is hardened by heating at a temperature within a range of 800.degree.-950.degree. C., thereafter high temperature tempering is carried out for 20-60 minutes at a temperature within a range of 570.degree.-700.degree. C.; then the surface layer of the inner periphery and/or outer periphery of said sintering body is heated; then if required, low temperature tempering (temper process) is carried out at a temperature within a range of 160.degree.-220.degree. C., and whereby the hardness of the surface layer, for which abrasive resistance is required, reaches a value of HRC 58-63 degree, and the hardness of the middle layer falls within a range of HRC 25-40 degree.

Dependencies are inferred from the claim text.