Rolling/sliding part and production method thereof

Abstract

A production method of a rolling/sliding part which includes applying a spherodizing annealing treatment to a steel to render an average particle diameter of the carbide of the surface layer portion in a range of 0.3 to 0.6 μm and a maximum particle diameter thereof 4 μm, to render the surface hardness 62 or more by Rockwell C hardness and to render a solid solution carbon amount in a residual austenite of the surface layer portion in a range of 0.95 to 1.15% by weight.

1 . A production method of a rolling/sliding part comprising:
 applying a spherodizing annealing treatment to a steel that contains C: 0.7 to 0.9% by weight, Si: 0.05 to 0.7% by weight, Mn: 0.05 to 0.7% by weight, Cr: 3.2 to 5.0% by weight, Al: 0.04% by weight or less, P: 0.03% by weight or less, S: 0.03% by weight or less, Ti: 0.005% by weight or less, O: 0.0015% by weight or less, at least one kind of Mo: less than 1.0% by weight and V: less than 0.50% by weight and a balance made of Fe and unavoidable impurities to make a lot of carbide precipitate;   processing into a predetermined shape to produce a processed part raw material;   heating in a carburizing atmosphere of which carbon potential is in a range of 1.0 to 1.5% at a temperature in a range of 870 to 950° C. to apply a first carburizing treatment followed by quenching;   subsequently heating in a carburizing atmosphere of which carbon potential is in the range of 1.0 to 1.5% at a temperature in a range of 870 to 910° C. to apply a second carburizing treatment followed by quenching; and   applying a tempering treatment to render an area ratio of a total precipitated carbide of the surface layer portion in a range of 15 to 25%, to render, 50% or more, by the area ratio, of the total precipitated carbide present in a surface layer portion a M 7 C 3  type and/or M 23 C 6  type, to render an average particle diameter of the carbide of the surface layer portion in a range of 0.3 to 0.6 μm and a maximum particle diameter thereof 4 μm, to render the surface hardness 62 or more by Rockwell C hardness and to render a solid solution carbon amount in a residual austenite of the surface layer portion in a range of 0.95 to 1.15% by weight.