| 摘要 |
PURPOSE:To strengthen the edge tip of a edge tool and to give this position excellent wear resistance and toughness by combining a local quenching and hardening treatment by laser beam irradiation with a toughness recovering treatment by the following low temp. reheating. CONSTITUTION:A blade tip part 3 and the outer blade part 4 in a rotary blade 1 of mowing machine, etc., are irradiated with the laser beam at the suitable high speed and rapidly heated. Then, by scanning at the high speed, the heat is conducted to the other position and the above heated part is rapidly self- cooled and quench-hardened. Further, after that, by executing the low temp. reheating treatment to the whole rotary blade 1 at about 200 deg.C, while suppressing lowering of the hardness in the quenching part to the min. limit as far as possible, the roughness at this part is recovered and the blade tip is strengthened. |
