| 摘要 |
PURPOSE:To decrease dimensional change in the stage of hardening by bringing a steel pipe in a high-temp. state into contact with a cooling liquid while rotating said material around the axial center at the rotating speed above a prescribed circumferential speed thereby obtaining approximately a uniform cooling condition irrespectively of the overhang rate at the end of the pipe and the size thereof. CONSTITUTION:A steel pipe 10 rolled on a feed skid 16 is carried between a set of rotational driving rollers 22 and is pressed from above by press rollers 24 from above. The pipe 10 is sandwiched by rollers 22, 24. While the pipe 10 is rotated around the axial center at a circumferential speed of >=1m/sec by the revolution of the rolls 22, the pipe is turned around a revolving shaft 32 together with upper and lower arms 28, 30 and is dipped into the cooling water in a water tank 36. Cooling water is ejected under high pressure toward the inside surface of the pipe 10 at the same instant when the pipe 10 is dipped in the water and at the same time, the water is ejected to the outside surface of the pipe 10 from an external header 48. The rollers 22 are then risen to release the pressing force and a kick-out arm 38 provided to the lower arm 28 is actuated to kick out the pipe 10 from below, thus transferring the pipe into the recess of a receiving arm 40. The pipe 10 is thereafter ejected under its own weight into a water tank 36 via a skid 46 in the water when an arm 40 is rotated. |
