METHOD FOR MANUFACTURING RACEWAY MEMBER, METHOD FOR MANUFACTURING VALVE TRAIN AND RACEWAY MEMBER

摘要

A method for manufacturing a raceway member, in which a hardness of a region to be plastically deformed is controllable in a stable manner and a sufficient rolling contact fatigue life is ensured by making a hardness of a region including a raceway surface sufficiently high, while suppressing increase in the manufacturing cost, includes a steel member preparation step, a heat treatment step, and a finishing step. The heat treatment step includes: a carbonitriding step, in which the steel member is heated to a carbonitriding temperature, which is a temperature not lower than A₁ point, and carbonitrided; a temperature holding step, in which the steel member is cooled from the carbonitriding temperature to a temperature range between not lower than a temperature 100° C. below A₁ point and lower than A₁ point and is held in the temperature range for not less than 60 minutes and not more than 180 minutes; and a induction hardening step, in which the high hardness region in the steel member including a region to become a raceway surface of the raceway member is induction hardened, without quench hardening of a low hardness region which is a region other than the high hardness region.