热轧板夹渣缺陷成因及控制

CAUSES AND CONTROL OF SLAG INCLUSION IN HOT ROLLED PLATE

利用SEM及EDS对河钢唐钢1700线热轧板夹渣缺陷的产生原因进行了分析。研究结果表明,夹渣缺陷主要为黑线和翘皮,两者成分中均含有一定量Na元素,主要为连铸过程中结晶器卷渣带入。从夹渣缺陷的产生机理入手,通过选择合适的氩气流量、水口结构、水口板面尺寸精度、水口浸入深度、保护渣,减少结晶器液位波动,稳定控制塞棒动作,减少拉速波动,优化捞渣、启渣线操作等措施,夹渣缺陷减少了至少60%,板卷夹渣率由4.9%降至1.5%,控制效果良好,产品质量得到有效提升。

The causes of slag entrapment defect in hot rolled coils produced in HBIS Tangsteel 1700 production line are analysed in this paper. The results show that the defects of slag inclusion are mainly black line and warping, and both of them contain a certain amount of Na element, which is mainly caused by the entrainment of mould slag in the continuous casting process. On the basis of the mechanism of slag inclusion, by selecting appropriate argon flow rate, nozzle structure, nozzle plate size accuracy, nozzle immersion depth, slag and protection, reducing the fluctuation of mould liquid, stabilizing the action of plug rod, reducing the fluctuation of pulling speed, optimizing the operation of slag removing and slag starting line, the slag inclusion is reduced by at least 60%, the slag inclusion rate of plate coil is reduced from 4.9% to 1.5%, and the control effect is good. Moreover, the product quality has been effectively improved.