321不锈钢冷轧板表面缺陷成因分析

Analysis of Surface Defect on 321 Stainless Steel Cold-rolled Sheet

针对321不锈钢冷轧板表面出现的线状缺陷,分别对321不锈钢进行了冶炼过程中试样夹杂物的成分分析、冷轧板的化学成分分析、缺陷位置扫描电镜及能谱检测分析。结果表明:产生缺陷的321不锈钢在冶炼过程中的LF工序产生高熔点的CaTiO_3类夹杂物,中包夹杂物的成分未发生明显变化,并在浇铸过程中被保护渣捕获,在连铸坯表面形成缺陷,导致冷轧板产生线状缺陷。通过对冶炼工艺及连铸保护渣物理性能进行优化,改善了钢中夹杂物类型及连铸坯表面质量,消除了321不锈钢冷轧板表面线状缺陷。

To find out the reason for line scale defects occurring on the su rface of 321 stainless steel cold rolled sheet,inclusions composition analysis of refining process,chemical composition analysis of cold rolled sheet,defect position scanning electron microscope and energy spectrum analysis were done.The analysis results showed that the high melting-point Ca Ti O3 inclusions informing at LF refining process of 321 stainless steel were not changing at ladle,then stably getting into the mold power,which resulted in surface defect of continuous casting slab and passes on cold rolled sheet.The inclusions type and the physical property of mold power were improved through optimizing refining process and physical property of mold power,and the line defect of 321 stainless steel cold-rolled sheet was removed finally.