| 摘要 |
PURPOSE:To perform the secondary winding of a rolled steel pipe without annealing it and to obtain a long-sized coiled steel pipe free from oxidized scales by hot rolling a blank pipe and coiling it on-line and then providing heat treatments to the rolled pipe by utilizing its potential heat. CONSTITUTION:A blank pipe 11 is heated by a heating furnace 1; the pipe 11 is then elongated in its axial direction by the difference of the peripheral speeds of rolls between adjoining stands while hot rolling the pipe 11 in sequence by a stretch reducer 2, to form it into a rolled pipe 12 having prescribed outer diameter and wall thickness. The pipe 12 is provided with various kinds of heat treatments in compliance with the kinds of steel and its end uses by utilizing its potential heat at the time of rolling till it comes to a coiler 4 or after it is coiled by the coiler 4 into a coiled steel pipe 13 or through these processes. Because the pipe 13 is taken up by rotating the rolls of the final stand of the stretch reducer 2, pinch rolls 3 and the coiler 4 by interlocking them with each other, and adjusting their speeds; the pipe 13 having a well shape is obtained without being flattened. |
