| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a parallel flange channel steel, rolling, which is a base stock for a square column without generating defect in shape. SOLUTION: At the time of rolling the parallel flange channel steel by making the billet into an intermediate rolled stock 42 by executing intermediate rolling to a rough shape billet 41 using two roughing universal mills 34, 36 and an edger mill 35 and finish tolling using a finishing universal mill 38, in a position where the web is situated on upper side to the flanges in the rough shape billet 41 and intermediate rolled stock 42, reduction with the roughing universal mills 34, 36 and finishing universal mill 38 is executed and also, in all of the roughing universal mills 34, 36 and finishing universal mill 38, the outside diameters of lower horizontal rolls 34b, 36b are taken as larger than the outside diameters of upper horizontal rolls 34a, 36a. Thickness draft difference between the web and the flanges in the roughing universal mills 34, 36 and the finishing universal mill 38 is controlled. |
