| 摘要 |
PURPOSE:To harden uniformly a steel pipe and to keep the surface of the pipe free from flawing, bending, etc. by immersing the steel pipe heated to a prescribed temp. into a water tank while rotating and injecting cooling water from a nozzle for an internal cooling water to the inside surface of the pipe. CONSTITUTION:A heated steel pipe 1 fed by a conveyance roll 2 is stopped in the position alongside a hardening device, and is placed on revolving rolls 9 by means of a feeding device consisting of a kick-in arm 3, an auxiliary arm 4, cylinder devices 5, 6 and an feeding skid 7. The several places in the longitudinal direction of the pipe 1 are grasped by means of two sets 4 pieces of upper and lower rolls consisting of press rolls 8 and rolls 9, and while the pipe is rotated by the rolls 9, the pipe is immersed into the cooling water in a water tank 34. An internal cooling nozzle mounted to a suspension frame 18 near the one end part of the pipe 1 is also lowered to eject high pressure cooling water to the inside surface of the pipe, whereby the inside and outside surface of the pipe are simultaneously hardened. The hardened steel pipe 1 is dropped onto an underwater skid 30 by the revolution of the rolls 9 and is removed to the outside by an ejector 31. |
