| 摘要 |
PURPOSE:To prevent the intrusion of cooling water into a steel pipe by interrupting the cooling water for the respective rolling rolls in the final hot rolling stage according to the positions of the leading end of the steel pipe passing through rolling mills and the average speed of the steel pipe passing through the rolling mills. CONSTITUTION:The value of the distance L0 between the leading end of a steel pipe 7 and rolling rolls 8, 8' in the stage of interrupting cooling water 9 according to the mill speed (v) of the pipe 7 is determined in such a way that said distance L0 attains vL0>=3.0 and position sensors 10, 10' are provided apart by LS from the rolls 8. 8'. The injection of the water 9 to the rolls 8, 8' is stopped upon elapsing of (LS-L0)/vsec after the sensors 10, 10' detect the leading end of the pipe 7. When the distance L' between the leading end position of the pipe 7 and the rolls 8, 8' attains vL'>=3.0 on passing of said leading end of the pipe 7 through the rolls 8, 8', the injection of the water 9 is resumed to cool the rolls. The similar procedures are followed in interrupting the cooling water 9 for the trailing end of the pipe 7. |
