镀锡板夹杂缺陷分析及控制

Analysis and control of inclusion defects of tinplate steel slab

针对镀锡板冷轧工序表面缺陷,在冷轧镀锡板取样并结合电镜进行分析,得出铸坯卷渣(Al-Ca-Mg-Na-O复合夹杂)及铸坯中Al2O3夹杂物是镀锡板冷轧板点/线状缺陷产生的主要原因。通过研究某厂镀锡板转炉-精炼-连铸全流程生产中夹杂缺陷产生原因,采取了控制转炉出钢氧、保证RH循环时间及降低吹氧量、优化连铸工艺如浸入式水口插入深度、氩气流量、结晶器保护渣等技术措施,有效控制了镀锡板夹杂类缺陷,对应冷轧工序改判率由之前2%~3%下降至控制后0.5%以下。

Aiming at the surface defects of cold-rolled tin plate,the main causes of spot/linear defects of cold-rolled tin plate were obtained by sampling and analyzing with electron microscope.It shows that the main causes of the spot/linear defects of tinplate are the slag entrapment(Al-Ca-Mg-Na-O complex inclusions)and Al2O3 inclusions.By studying the cause of inclusions in the process of converter-RH refining-continuous casting,the inclusions were controlled effectively by controlling the converter tapping oxygen,extending circulation time of deoxidization-alloying and reducing oxygen blowing in RH refining process,optimizing the continuous casting process including nozzle immersion depth,argon flow rate,mold fluxes,and the amendment rate in cold rolling process caused by steelmaking process reduced obviously from 2%-3%to below 0.5%.