| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent tempering generated by the overlapping of the start end and terminal end of laser irradiation without forming a laser beam with a specified shape when the annular hardening face of a workpiece is subjected to hardening.SOLUTION: Provided is a laser hardening method in which a laser is spirally emitted to the annular hardening face of a workpiece so as to be made far from the center or close to the center every time circulation is performed, the temperature of the region emitted with the laser is heated to an A3 transformation point or higher, and, before the temperature of the first circulation part reaches a martensite transformation starting point or lower, the laser is emitted in such a manner that a part of the second circulation part succeeding to the first circulation par is superimposed on the first circulation part.</p> |
