1994 年 45 巻 4 号 p. 383-387
A high-power YAG laser was applied to the surface hardening of carbon steels containing 0.18∼0.54wt%C, and the relationships between laser processing conditions and surface hardening were investigated by hardness and microstructure.
The structure of the hardened zone underwent complete martensitic transformation in all of the carbon steels tested, and its hardness increased with greater carbon content. Under identical irradiation conditions, the hardened zone expanded with increasing carbon content. A hardened zone extending from the surface to a depth of 1.0mm was obtained at a laser power of 1.0kW and a scanning speed of 1mm/s.
It was found that in the surface hardening of carbon steels, a high-power YAG laser can be used to control the hardened zone by selecting the appropriate irradiation conditions.