Influence of Thickness Profile after Sizing Press on Width Profile at Head and Tail Portions of Slab

抄録

In hot strip mills, use of the sizing press and horizontal rolling results in a narrower width at the head and tail portions of slabs in comparison with the middle portion, and these narrow portions, called “width drop,” cause yield loss. Some studies reported that width drop results from the difference in the width spread in horizontal rolling depending on the distribution of the dog bone profile along the slab longitudinal direction. However, the experimental and simulated data in other papers indicated that “width shrinkage” occurs around the head and tail portions after horizontal rolling of slabs with the dog bone profile. Although width drop might actually be influenced by width shrinkage as well as by width spread, few reports have clearly described the mechanism of width shrinkage. Therefore, this paper focuses on an investigation of the influence of width shrinkage during horizontal rolling on width drop. Experiments and FE analyses of horizontal rolling of slabs with the dog bone profile were carried out to investigate the mechanism of width shrinkage. The FE analyses revealed that width shrinkage occurred around the head and tail portions of slabs just after and just before the horizontal rolls, respectively, in horizontal rolling of slabs with a dog bone profile as the cross section. The results also suggested that the distribution of the rolling direction velocity along the width direction around the head and tail portions causes width shrinkage during horizontal rolling.