IF钢热轧边部线状缺陷治理措施

Treatment measures of edge seam defects for hot rolling IF steel

通过微观检测、理论与实验分析,已初步确定IF钢边部线状缺陷的产生机理是:中间坯侧面褶皱+角部金属翻转。为进一步排除钢区的影响,本文首先进行了缺陷铸坯轧制试验,通过该试验明确了铸坯气泡、裂纹并不是边部线状缺陷的产生原因;然后针对缺陷产生机理,分析了各种治理措施的优缺点,最终选择定宽机凹型砧板方案。为确定方案的有效性,在生产现场进行了定宽机空过试验,结果表明不经过定宽机侧压的钢卷普遍出现了边部线状缺陷,而经过凹型砧板侧压的钢卷则几乎完全消除了这一缺陷。批量生产数据也表明,定宽机全部采用凹型砧板后缺陷发生率显著下降,验证了理论分析的正确性与治理方案的有效性。

This paper has been preliminarily determined that the formation mechanism of edge seam defects of IF steel is that side creases on the side of intermediate billet+corner metal turnover,based on the micro inspection,theoretical and experimental analysis.In order to further eliminate the influence of the steel area,this paper firstly carried out the rolling test of the defective billet,through which it was clear that the bubbles and cracks in the billet were not the causes of edge seam defects;then,according to the mechanism of the defects,the advantages and disadvantages of various treatment measures were analyzed,and finally the concave anvil scheme of the slab sizing press was selected.In order to determine the effectiveness of the scheme,the empty pass test of the lab sizing press was carried out on the production site.The results show that the edge seam defects are commonly found in the steel coil without the side pressing,while the steel coil with the side pressing of the concave anvil completely eliminates the defects.The mass production data also show that the defect rate of decreases significantly when the concave anvil was applied,which verifies the correctness of the theoretical analysis and the effectiveness of the treatment scheme.