| 摘要 |
PURPOSE:To improve the cut-off yield of the end of a rolling material regardless of the total changing quantity of a slab-width by keeping the length of a slab- end, which comes into contact with the taper faces at both sides of the parallel face of a preforming die, within a specific range, in preforming the end width of a slab at the time of the vertical and horizontal, continuous rolling of slab. CONSTITUTION:A crop loss is reduced into minimum when a part Lc at the end of a slab is left in a condition of 0<=LC/WO<0.5, without preforming said slab end by a parallel-face preforming die 20 having taper faces at its both sides at the time of continuously rolling the slab by vertical and horizontal rolls. In this case, said condition is suitable when the total changing quantity DELTAWE of slab width is, for instance, <=200mm., but not suitable when the DELTAWE is larger than 200mm.. When the length LA of the slab end which comes into contact with the taper faces at both sides of the parallel face LP of preforming die 20, is conformed to the relation of an equation applicable within a range of 0<LA/LB<1; a fish tail and a corner droop are minimized, and crop loss is reduced and rolling yield is improved regardless of the total changing quantity DELTAWE of slab width. |
