| 摘要 |
PURPOSE:To perform hardening and tempering without requiring separately a tempering furnace by pulling up the work which is cooled and hardened in a salt vessel from the inside of the salt and subjecting the work to force air cooling then dipping the work again into said salt and tempering the same. CONSTITUTION:The salt 4 in a salt vessel 3 in heated and held to and at the temp. optimum for the heat treatment of a work 1. Air nozzles 8 are provided above the liquid surface thereof. The work 1 is heated to a prescribed temp. in a heating furnace and is fed into the vessel 3 where the work is dipped in the salt 4. The work is thus quickly cooled and hardened. The work 1 pulled from the inside of the salt 4 is held suspended as it is above the liquid surface of the salt 4 and high pressure air is injected thereto from the nozzles 8, by which the work is cooled. The work 1 cooled down to the prescribed temp. is again dipped in the salt 4 but work 1 attains approximately the same temp. as the temp. of the salt 4 in short time and thereafter the work is held at said temp. for the time required for tempering. The work 1 is then suspended in the same way as mentioned above and is cooled by the air from the nozzles 8 for the prescribed time, by which the tempering is completed. |
