| 摘要 |
PURPOSE:To improve the unit of roll by successively rolling down a web part with horizontal rolls respectively having a projecting shape and recessed shape to form the web to a stepped shape then subjecting the inside width of the web to expansion rolling with horizontal rolls of a variable roll width type. CONSTITUTION:The projecting parts and recesses respectively having lengths l, l' and depths d, d' are formed to both ends of the horizontals rolls of universal roughing mills U1, U2. The lengths and depths are specified to l'>=l, d'approx.=d. The ends having the length l and depth d are first formed at the both ends of the web of a rolling material by the rolling mill U1. Only the ends are further rolled down by the horizontal rolls 24 of the rolling mill U2 to form the same to the prescribed step part. The inside width of the web of the rolling material is expanded by the repetition of such rolling and the web is subjected to the expansion rolling up to the prescribed inside width by the variable width rolls 28, 30 of an intermediate rolling mill U3 and finishing mill Uf. The number of the rolls to be held is decreased and the unit of roll is improved by the above-mentioned method. |
