METHOD FOR MANUFACTURING TRACK MEMBER, METHOD FOR MANUFACTURING VALVE DEVICE, AND TRACK MEMBER

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a track member with which the hardness in a range including a rolling surface is enhanced sufficiently while suppressing manufacturing cost from rising, a sufficient service life to the rolling fatigue is secured by imparting the high resistance to the rolling fatigue, and the hardness in a plastic deforming range can stably be controlled. SOLUTION: The method for manufacturing the track memberis provided with; a steel-made member preparing process for preparing the steel-made member restraining carbon-content and chromium-content; a heat-treatment process; and a finish-working process. The heat-treatment process comprises; a carbo-nitriding process, in which the steel-made member is heated and carbo-nitrided; a cooling process, in which the carbo-nitrided steel-made member is cooled to the temperature of lower than A1point from the carbo-nitriding temperature so that the steel constituting the steel-made member is made to a pearlitic transformation; and a high frequency induction hardening process, in which in the steel-made member, the high hardness range is applied to the high frequency induction hardening so as not to harden into a low hardness range except the high hardness range containing the range to become the rolling surface of the bearing member. COPYRIGHT: (C)2008,JPO&INPIT