| 摘要 |
<p>PURPOSE:To execute quenching and tempering to a long-sized steel product with simple apparatus at a low cost by executing high-frequency induction heating while shifting the long-sized steel product, the quenching with cooling liquid injection and the tempering with the high-frequency induction heating and further, executing after-cooling with the cooling liquid. CONSTITUTION:The long steel product 1 of ball screw, etc., is shifted to the arrow mark A direction while rotating around the center axis. At first, after heating the steel product 1 to the quenching temp. with the induction heating coil 10 of a truncated-form semi-opening type high-frequency quenching with length L1, by spraying rapid cooling liquid (l1) from a rapid cooling liquid injection jacket 20, the rapid cooled quenching is executed. Successively, after removing the cooling liquid (l1) for quenching by injecting compressed air K from an air nozzle 50, the electric current is conducted to a high-frequency tempering coil 30 having length L2 longer than 1.5XL1, and heating for tempering are executed with this induction current, and at last, the steel product is cooled to room temp. by injecting the cooling liquid (l2) through jackets 40a-40c from three ways.</p> |
