Skin pass rolling is considered as the final forming stage in cold‐rolled close annealed steel. Surface properties and flatness are the key attributes for automotive customers. Efficient skin pass rolling overcomes surface defects that lead to material rejection. This study portrays a brown stain defect with higher defect severity. The brown stain defect is observed in a few coils that are processed through alkaline electrocleaning (ECL). Coils bypassing ECL do not show such defect. Defect characterization through scanning electron microscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy shows initiation of oxidation of steel substrate. The presence of skin pass fluid residues in the defected area is the root cause for the stain formation. Techniques such as glow discharge optical emission spectroscopy, Kelvin probe, Raman spectroscopy, and electrochemical tests emphasize the role of final electrode polarity in ECL with the nature of passive oxide film formed when skin pass fluid is applied on the steel surface. This study reveals that skin pass fluid applied on anodically cleaned coils provides a uniform passive surface that restricts the defect formation.

中文翻译：

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电清洗过程中阴极极性对冷轧紧密退火钢皮通过后棕色斑点缺陷形成的影响

光整冷轧被认为是冷轧紧密退火钢的最终成形阶段。表面特性和平坦度是汽车客户的关键属性。高效的光整皮轧制可克服导致材料报废的表面缺陷。这项研究描绘了一个棕褐色的缺陷，其缺陷严重性更高。在通过碱性电清洗（ECL）处理的一些卷材中观察到棕色斑点缺陷。绕过ECL的线圈未显示此类缺陷。通过扫描电子显微镜，傅立叶变换红外光谱和拉曼光谱进行的缺陷表征显示了钢基底氧化的开始。缺陷区域中存在皮肤通过液体残留物是形成污渍的根本原因。辉光放电光发射光谱法，开尔文探针，拉曼光谱法和电化学测试强调了最终电极极性在ECL中的作用，其特征是当在钢表面上施加表皮通过液时形成的钝化氧化膜的性质。这项研究表明，在经过阳极清洁的线圈上使用的通过皮肤的流体可提供均匀的钝化表面，从而限制了缺陷的形成。