冷轧无取向硅钢表面白线缺陷成因分析与控制

Genetic analysis and control of the surface white sliver defect on the cold-rolled non-oriented silicon steel

对冷轧无取向硅钢表面白线缺陷的特征和分布进行了描述,通过扫描电镜(SEM)分析、铸坯机清试验、连铸坯表面清洗检查、铸坯表面缺陷跟踪试验、塞棒吹气试验等,研究了产生白线缺陷的原因,并提出了此类缺陷的控制措施。结果表明:白线缺陷与连铸坯表面夹渣有关,缺陷的产生是与结晶器液面活跃程度及保护渣熔化状态有关。适当增大连铸塞棒吹氩量、增加拉速及优化保护渣物性参数,白线缺陷发生率由原来88%降至8%。

A kind of white sliver defect appeared on the cold-rolled sheet surface of non-oriented electrical steel was sys- tematically investigated in this paper, by performing the scanning electron microscopy （SEM） observation, slab scarfing examination, slab surface pickling treatment and the stopper blowing-argon experiment. The results show that the white sliver defect is originated from mold slag entrapment, which is related to the activation degree of the molten steel flow and the melting status of the powder. By appropriately increasing the blowing argon flow rate of the stopper, increasing the casting speed and optimizing the physical properties of the mold powder, the occurrence of white sliver defect rate on the cold-rolled sheet surface is reduced from 88% to 8%.