| 摘要 |
PURPOSE:To inexpensively produce a rotating shaft of improved fatigue limits by hardening the stepped part of the rotating shaft having the stepped part by laser beam scanning. CONSTITUTION:A laser beam 10 is scanned on the surface of the stepped part A of a rotating shaft 1. At this time, a blackening agent of a phosphate system is beforehand coated on the surface of the part requiring hardening, that is, the stepped part A, in order to increase the absorption rate of the beam 10 and improve treatment efficiency. While the shaft 1 is moved back and forth in an axial direction X, it is revolved in a Y direction and the beam 10 is scanned. Hence, the beam 10 scans the surface of the shaft 1 radially, whereby the hardening is accomplished. |
