| 摘要 |
PROBLEM TO BE SOLVED: To provide steel parts for high bearing resistance, suitable for steel parts requiring high strength, making compact, etc., such as gears, cums, and bearing parts, attended by rolling and sliding and requiring rolling strength and wear resistance, and their production. SOLUTION: In the surface structure to be brought into contact, a dual-phase structure composed of irregular-shaped and hemp leaf-shaped martensite finely divided and formed into superfine state buy means of dispersed fine nitrides and/or carbonitrides having an average grain size of <=0.3μm at least is provided. Carbides of <=3μm are dispersed to reinforce the hardness of the surface part. The steel parts can be produced by performing a stage where nitriding or carbo-nitriding treatment is applied to precipitate AlN into superfine state by means of the nitrogen allowed to penetrate from the surface part and a stage where hardening or hardening and tempering are carried out from a temp. region in which a base phase is composed of austenite. |
