镀锡板表面白条缺陷原因分析及改进措施

客户在使用首钢镀锡板时发现带钢表面存在白条缺陷，严重影响产品美观和使用，通过对缺陷进行扫描电镜等微观分析、工艺优化及试验跟踪，明确了白条缺陷的根本成因是热轧带钢表面的氧化麻点压入。通过优化钢坯加热工艺、优化精轧高压水除鳞、机架间冷却水和轧辊防剥落水开启制度等改进措施，基本消除了热轧带钢表面氧化麻点压入，有效控制了镀锡板表面白条缺陷的发生，提高了产品质量。

Cause analysis and improvement measures of white line defect on tinplate surface

Customers complained that the white line defects were observed on the surface of strip steel of Shougang tinplate， which seriously influenced the appearance and use of product. Through microstructure analysis of detects by scanning electron microscope （SEM） as well as process optimization and test tracking， it was clearly found that the root cause of white line defects was the rolled-in scales on the surface of hot rolled strips. By optimizing the heating process of billet， the high-pressure water descaling process in front of finishing rolling， the switching system of interstand cooling water and anti-peeling water of roller， the rolled-in scales on the surface of hot rolled strips were almost eliminated. The occurrence of white line defects on surface of the tinplate was effectively controlled and the quality of product was improved.