To provide a rolling member having the improved endurance life in a hostile environment for use in a constant velocity joint; to provide the constant velocity joint having the long life even in the hostile environment; and to provide a manufacturing method therefor.
The method for manufacturing the rolling member for use in the constant velocity joint comprises the steps of: preparing a steel member; carburizing or carbonitriding and quenching; induction-hardening; and finishing. In the step of preparing the steel member, the steel member is made from steel and is formed into a contour shape of the rolling member for use in the constant velocity joint. In the step of carburizing or carbonitriding the steel member, the steel member is carburized or carbonitrided and then quench-hardened. In the step of induction-hardening the steel member, a region including a part to be the rolling surface of the rolling member for use in the constant velocity joint is further quench-hardened to control an amount of retained austenite in a region between the surface to be the rolling surface and a plane of 0.3 mm or less in depth therefrom to 50 vol.% to 70 vol.%. In the step of finishing the steel member, the steel member is processed to be finished.
NAKAJIMA HIROKAZU
Toshio Morita
Yoshihei Nakamura
Yutaka Horii
Hisato Noda
Masayuki Sakai