电镀锌基板边部白线缺陷成因分析及控制

Cause Analysis and Control for White Line Defect on Edge of Galvanized Substrate

某冷轧厂生产的电镀锌基板边部出现严重的白线缺陷问题,严重影响客户的涂装和产品外观,本文采用扫描电镜、金相显微镜对白线缺陷微观特征进行系统分析,缺陷位置存在较多的轧制条痕,并且有Si、O元素的富集;同时采用激光共聚焦显微镜对缺陷的三维形貌表征,进一步表明缺陷位置和正常位置条痕深度存在差异,结合产线的实际工况,对缺陷在热轧-冷轧-退火全流程工序遗传演变规律进行探索,明确缺陷的形成机理。在此基础上,提出一贯制的优化措施,有效控制边部白线缺陷,提高产品的边部质量。

The white line defect appeared at the edge of the electro-galvanized substrate steel produced by the cold rolling mill seriously affected customer's painting and product appearance.We systematically analyzed the microscopic features of white line defects by scanning electron microscopy and metallographic microscope in this paper.There are many rolling streaks in the defect position,and Si and O elements were enriched in the defect location.At the same time,the threedimensional shape characterization of the defects was carried out by laser confocal microscopy,it further indicates that there is a difference in striation depth between the defect position and the normal position.Combined with production line conditions,the genetic evolution of defects in hot rolling -cold rolling -annealing process was explored to determine the formation mechanism of defects.On this basis,the optimization measures of consistent system are proposed to effectively control the white line defects at the edges and improve the edge quality of the products.