| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain the circular steel tube free from an uneven thickness and with a circular cross-section by online measuring the angle of twist of a tube stock during rolling the tube stock, and readjusting the measured angle of twist to a target value. SOLUTION: A through-hole 1 is provided in the connecting part 3 of the tube stock 20 and the tube stock 20. The detecting sensors of the through-holes 1 are arranged on the inlet side and the outlet side of each stand, and rolling is performed while measuring and adjusting the angle of twist. Consequently, since 'the angle of twist' can be readjusted (corrected) in the middle of an operation, an angularity on the inside surface of a product are reduced, the steel tube free from the uneven thickness and with the circular cross section can be stably manufactured.</p> |
