| 摘要 |
PURPOSE:To prevent the penetration of the coolant, and to meke possible the whole zone of steel pipe to be favorably hardened, in case of executing the hardening of the hot steel pipe by injecting the coolant while the hot pipe is being conveyed, by making controllable the angle of injection of the injection nozzle over the range from the direction toward the central zone of the pipe to the direction tangent to the periphery. CONSTITUTION:The central zone of the steel pipe 2, being conveyed in the arrowed direction 9, is cooled by the coolant injected toward the central Zone of the pipe 2 from the injection nozzle 3a. When the steel pipe 2 is moved forward and its rear end comes to a point opposite to the injection nozzle 3a, the large gear 7 turns in a specified angle; hereby, the direction of the injection nozzle 3a is changed into the tangent to the periphery; the angle of injection beta is this controlled. According to this method, the penetration of the coolant into inner surface of the steel pipe2 is prevented. In case of the tip of steel pipe 2 being opposite to the injection nozzle 3a, the similar control is executed. |
