热轧卷表面线状缺陷分析

为了研究热轧卷表面线状缺陷产生的原因，通过扫描电镜和能谱对热轧卷表面线状缺陷的形貌和成分进行分析，并对缺陷在钢卷断面方向的分布进行统计。结果表明，结晶器保护渣卷入和钢液中的夹杂物是导致热轧卷表面线状缺陷产生的主要原因，而缺陷分布与断面宽度有关。在研究线状缺陷形成机理的基础上，采取钢包顶渣改质、控制钢包镇静时间、优化保护渣性能和水口结构、火焰清理、优化氩气吹气量等控制措施，同时改进相关的工艺条件，使该类缺陷发生率得到有效控制，热轧卷表面线状缺陷率由0.63%降至0.30%以下。

Analysis of sliver defect on hot rolled coil surface

In order to research the causes of sliver defect on hot rolled coil surface, the morphology and components of sliver defect on hot rolled coil surface are analyzed by scanning electron microscope(SEM) and energy dispersive spectrum(EDS), and the distribution of defect in section direction is figured out. The results show that the defect is mainly caused by the mould powder entrapment and inclusions in molten steel, and the distribution of defect is related to the width of section. According to the formation mechanism of surface sliver defects, this defect is effectively controlled by modifying the ladle top slag, increasing the sedation time of ladle, optimizing performance of mould powder and structure of nozzle, scarfing, decreasing argon blowing to reduce liquid level fluctuation and improving other relevant process conditions. The surface sliver defect rate is reduced from 0.63% to below 0.30% through above process improvement.