| 摘要 |
PURPOSE:To prevent the shape of web from deterioration by finely adjusting the inside width of web of roughly rolled billet according to a specified condition with a universal mill with a divided roll of which the roll width is variable for rolling down web thickness before finish universal rolling. CONSTITUTION:The roughly formed billet which is passed through a break down mill 5 is repeatingly rolled until the web thickness Tw, flange thickness Tf and flange width L of the roughly formed billet become the target dimension with a group of roughing universal mills which are constituted of a roughing universal mill 1 and edger mill 2. On the next stage, the billet is reducing adjusted at least once so as to become a prescribed inside width Bw of web (the dimension that the thickness of flange on both sides is subtracted from the web height of the roughly formed billet) and then performed with finish rolling that is combined with raising-up of flange with a universal mill 4. In the fine adjustment of the inside width of web before finish universal rolling, each draft is controlled so as to satisfy the formula. |
