| 摘要 |
<p>PURPOSE:To harden safetly and cleanly a material to be treated without forming an oxide film by subjecting said material to high-frequency heating in a hermetic treating vessel in which a non-oxidative gaseous atm. is maintained then cooling the material by self-cooling and force gas cooling with the non-oxidative gas. CONSTITUTION:The member 9 to be treated is mounted to a jig 11 for mounting the member to be treated in the treating vessel 2 and is lowered; then the vessel is hermetically closed by a cap member 1. Gaseous nitrogen is introduced through a cooling medium supply pipe 5 from an ejecting hole 8 provided to a high-frequency hardening coil 7 to maintain the non-oxidative gaseous atmosphere in the vessel 2. While the jig 11 is rotated, the member 9 is high- frequency-heated by the high-density electric power via the coil 7. The member 9 in the high-temp. region is cooled by making combination use of the self- cooling by the heat capacity of the member 9 itself and the force gas cooling of the high-pressure gaseous nitrogen injected from the hole 8. The material is further subjected to the force air cooling by high-pressure air in the low temp. region where oxidation is little.</p> |
