连铸坯表层夹杂轧制过程演变行为

Evolution behavior of slab surface inclusion during rolling process

为了研究连铸坯表层夹杂物在轧制过程中的演变行为,对板坯表层线缺陷进行分析发现,缺陷距表层几十微米,宽度约为200μm,对其内物质进行能谱分析,发现有钠、钾元素,说明该缺陷可能是由于结晶器流场不合理等原因造成保护渣卷渣。通过建立连铸板坯表层夹杂物轧制过程有限元模型,对连铸坯头部、尾部不同位置夹杂物轧制过程中的演变行为进行了分析。结果表明,随着轧制道次的进行,夹杂物周边出现裂纹,并且随着轧制过程的进行,夹杂物周边的裂纹越来越大。轧件头部、尾部夹杂物逐渐向轧件表面移动,距离表层越近的夹杂物越容易迁移到轧件表面,而深度相同、水平位置不同的夹杂物,距轧件边缘距离越远,在轧制过程中越容易迁移到轧件表面。

In order to study the evolution behavior of slab surface inclusion during rolling process.By analysis of the line defect on the surface of the slab,it was found that the defect was about tens of microns away from the surface and the width was about 200μm.Energy spectrum analysis showed that Na and K elements were found in the inner material,indicating that the defect might be caused by slag entrapment due to the irrationality flow field of mold.The evolution behavior of inclusions at different positions of the head and trial slab in the rolling process was investigated by establishing the finite-element simulation of surface inclusion in the rolling process of continuous casting slab.Results showed that there were cracks around inclusion and these cracks grew with rolling pass.Inclusions in the head and trail slab migrated to the surface of the slab,and the closer the inclusions were to the surface,the easier they would migrate to the slab surface.With the same depth and different horizontal position,as the inclusions were farther away from the slab edge,they were more likely to migrate to the slab surface.