| 摘要 |
PURPOSE:To disperse a shearing load by a flame hardening layer and to prevent sinking a laser hardening layer by forming the laser hardening layer and the flame hardening layer successively from a surface to an inner part on a cutting edge of a casting die for trimming. CONSTITUTION:After finishing the die 5 by cutting, grinding, or polishing, the hardening of the cutting edge 6 is performed by a barner 7 to form the flame hardening layer 6a. Then, a graphite power is applied on the flame hardening layer 6a to form a absorbing layer for the laser beam. After that, while the laser beam 12 is projected on the flame hardening layer 6a, a base 9 is moved to control, the laser hardening is performed covering whole required hardening part of the flame hardening layer 6a to form the thin laser hardening layer 6b on the surface of the flame hardening layer 6a. Therefore, at the time of trimming, the shear load transferfed from the laser hardening layer 6b to the flame hardening layer is transferfed to a non-hardened layer dispersedly by the flame hardening layer 6a. |
