| 摘要 |
PROBLEM TO BE SOLVED: To dissolve defects in shape such as difference in level at the tip of flanges, shrinkage in the middle part of the web and, furthermore, difference in level in fillet parts in the rolling of channels whose outside measure is constant. SOLUTION: After executing thickness reduction and edging of the web and flanges to the rough shape billet 38 for channels using a 1st universal roughing mill 32 and edger mill 33 and flatening reduction of the bulged part 41a, 41b which are formed on the opposite side of extension of the flanges in both end parts of the web by reduction with the 1st universal roughing ill 32, by executing rolling with the 2nd universal roughing mill 34, edging of the flanges is executed, also the reduction of the web height is executed in accordance with the target thickness of the channel and, using the universal finishing mill 35, the finish rolling of the web and flanges of one pass is executed. Intermediate rolling is executed so that the thickness in the middle of the web of a material 41 to be rolled before the finish rolling is larger than the thicknesses in both end parts of the material 41 to be rolled and the thickened parts 50a, 50b which are formed at the tips of the flanges of the material 41 to be rolled are uniformly flowed in the rolling direction by the finish rolling. |
