Ntn Corporation

Naoki Yashiro

Kouya Oohira

Takahiro Okuno

Provided is a method of manufacturing a machine part having a radial crushing strength of 120 MPa or more, including: a compression molding step of compressing raw material powder including, as a main component, metal powder that is capable of forming an oxide coating and has a pure iron powder content ratio of 95 mass % or more, to thereby obtain a green compact () having a predetermined shape; and a coating forming step of causing the metal powder to react with an oxidizing gas while heating the green compact () at a temperature lower than a sintering temperature of the metal powder in an oxidizing gas atmosphere, to thereby obtain a reinforced green compact () in which the oxide coating () is formed between particles of the metal powder.

Method for producing machine component

A sintered compact having a density of 7.5 g/cmor more is formed by mixed powder. The mixed powder is obtained by mixing graphite powder having an average particle diameter of 8 &#x3bc;m or less and diffusion alloyed steel powder. The ratio of the graphite powder is from 0.05 wt % to 0.35 wt % with respect to 100 wt % of the diffusion alloyed steel powder. Or, the mixed powder is obtained by mixing the graphite powder and completely alloyed steel powder. The ratio of the graphite powder is from 0.15 wt % to 0.35 wt % with respect to 100 wt % of the completely alloyed steel powder.

Growing community of inventors

Mie, Japan

Naoki Yashiro