To provide a needle-like roll bearing raceway member whose rolling fatigue life under a severe environment is improved, a needle-like roll bearing having a longer service lifetime even under a severe environment, and a manufacturing method for the needle-like roll bearing raceway member.
The manufacturing method for the needle-like roll bearing raceway member includes a steel member preparation step, a carburizing or carbonitriding hardening step, a high-frequency hardening step, and a finishing step. In the steel member preparation step, a steel member made of steel and shaped into an outline shape of the needle-like roll bearing raceway member is prepared. In the carburizing or carbonitriding hardening step, the steel member is quenched and hardened after executing carburizing or carbonitriding hardening to the steel member. In the high-frequency hardening step, a region including a part to be a rolling face of the needle-like roll bearing raceway member is further quenched and hardened so that a remaining amount of austenite in a region having a depth of ≤0.3 mm from the face to be the rolling face is ≥50 vol.% and ≤70 vol.%. In the finishing step, finish processing is executed to the steel member.
NAKAJIMA HIROKAZU
Toshio Morita
Yoshihei Nakamura
Yutaka Horii
Hisato Noda
Masayuki Sakai