热轧带钢边部翘皮缺陷成因分析

为了探明低碳钢在带钢轧制过程中出现边部翘皮缺陷的形成原因,取样分析了翘皮缺陷形貌及夹杂物成分,并采用ø750 mm×550 mm高刚度二辊热轧机组进行实验室模拟轧制分析翘皮缺陷演化过程。通过建立不同轧制方案,探明了热轧带钢翘皮缺陷形成于精轧道次,缺陷的产生与坯表面质量和边部原始凝固组织无关,轧材在轧制过程中由于边部不均匀变形形成侧面凹陷,凹陷在后续轧制中被轧制压缩闭合,并翻转到表面成为翘皮缺陷。最后,工业生产试验表明,倒角铸坯可提高轧材边部在轧制过程中的温度和均匀性,抑制轧材边部不均匀变形,有效降低翘皮缺陷的发生率。

Causes analysis of surface upwarping defects on hot rolled strip

In order to find out the cause of the surface upwarping defects of low carbon steel during hot strip rolling,the morphology and inclusion composition of upwarping defects were analyzed by sampling. The laboratory simulation of forming process of upwarping defect was analyzed by simulating rolling with a ø750 mm×550 mm high rigidity double-roll hot strip mill. By establishing different rolling schemes, it is proved that the upwarping defect of hot strip is formed in the finish rolling, and the defect is independent of the billet surface quality and cast edge original microstructure. In the rolling process, the side hollow is formed due to the uneven deformation of the edge. In the rolling process, the rolled material is dented on the side due to the inhomogeneity deformation of the edge, and the depression is compressed and closed by rolling in the subsequent rolling and turns to the surface to become the defect of warping skin. Finally, the industrial production test shows that chamfering slab can improve the temperature and uniformity of rolled edge during rolling, which restrain the uneven deformation of rolled edge, and effectively reduce the incidence of upwarping defects.