| 摘要 |
PURPOSE:To shorten a rolling line, to prevent the lowering of a finishing speed, and to decrease the temperature drop of a rolling material by installing a spiral looper between a coil box located behind a sheet-bar roughing mill and a finishing mill, and fixing a welder. CONSTITUTION:A sheet bar S1 rolled by a group 2 of roughing mills and housed in a coil box 5 is finished by a finishing mill 3 through a gap of fixed type welder 10 and a spiral looper 11. The rear end of a preceding sheet bar S1' is sheared 6 and fixed to the welder 10. The front end of a succeeding sheet bar S1 is also sheared 6 and fixed to the welder 10 to abut and weld it to the rear end of preceding one. During said operation, the looper 11 is unwound to perform finish rolling 3 continuously at a constant speed. Accordingly the finish rolling 3 is operated under a constant back tension and at a constant speed without transferring the welder 10 and requiring a swing roll, which are usually operated; thus the rolling line is shortened and the temperature drop of sheet bar is decreased. |
