| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for easily manufacturing a hardened steel pipe free from curves and deformations, and an apparatus. SOLUTION: This continuous hardening method comprises, connecting heat treated steel pipes W1 and W2 in front and back by penetrating a plug 21 of a hollow tube through their abutting parts with a plug mounting means 2, hardening the steel pipes by continuously heating them with a heating coil 4 for hardening, while transferring them; heating and drying a remaining liquid coolant in the pipe with a heating coil 7 for drying, after hardening and cooling the pipes; then detaching the plug 21 with a plug detaching measure 8, and discharging it to an discharge table 10; and circulating and transporting the detached plug 21 to the plug mounting means 2 by a plug conveyance measure 12.</p> |
