| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power transmission shaft improved in fatigue strength by improving the familiarity of a contact portion with other components to reduce tensile stress on the contact edge, and also to provide its manufacturing method. <P>SOLUTION: The power transmission shaft of medium carbon steel comprises torque transmission grooves formed in ends 2, 3. A carburized and quenched layer is formed on the surface layer of each of groove formed portions 5, 6 of the ends 2, 3. An remaining amount of austenite is 20% or more on the surface of the carburized and quenched layer. <P>COPYRIGHT: (C)2008,JPO&INPIT |
