| 摘要 |
PROBLEM TO BE SOLVED: To lengthen a life by applying the heat treatment including carburization, constituting a rolling and sliding part from a steel material in which spherical carbide is dispersed and precipitated in a carburization layer matrix, and specifying the distance between spherical carbide. SOLUTION: Known steel such as SUJ2, SCr42O, SAE512O of JIS is used as a steel material. The heat treatment including carburizing is composed of a first process for performing carburizing or carburizing quenching, a second process for precipitating fine spherical carbide to a carburization layer after quenching, and a third process for performing high-density carburizing quenching so that the carbon density of the front surface may be higher than the carbon density on the front surface obtained by the first process. Therefore, the distance between the spherical carbide is 15μm or less in the minimum grain distance, and the rolling life of a rolling bearing using these parts in dirty oil and cleaning oil is lengthened. The life of a slide bearing using the parts is also prolonged.
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