平整液对冷轧带钢表面黄斑缺陷的影响

平整是冷轧带钢生产的重要工序,其可以消除带钢的屈服平台,提高其成形性能和质量。但平整液可诱发冷轧带钢表面黄斑缺陷的产生。采用扫描电镜和电化学分析手段,分析了冷轧带钢表面黄斑缺陷特征及其形成机制。结果表明:冷轧带钢表面平整黄斑缺陷的主要成分为铁氧化物,其产生过程与冷轧带钢表面电位和裂开的氧化膜电位差值有关。在平整液作用下,冷轧带钢表面氧化膜破损处可形成新的氧化膜,其生成速度越快,越有利于降低平整黄斑缺陷的发生率。平整液中添加剂磷酸盐和钼酸盐可以提高冷轧带钢表面氧化膜的生成速度,从而避免黄斑缺陷的产生。

Effect of temper solution on the yellow spot defect formation of the cold rolled strip

Temper was an important process in the production of cold rolled strip,the yielding point elongation of strip could be eliminated and the formability and quality of strip could be improved.However,the yellow spot defect on the cold rolled strip surface could be induced by the temper solution.The characteristics and formation mechanism of the defects on cold rolled strip surface were studied by means of SEM and electrochemistry methods.The results show that the main component of yellow spot defects on the cold rolled strip surface is iron oxide,which is related to the potential difference between the cold rolled strip surface and cracked oxide film.The new oxide film formation on the cold rolled strip surface with the cracked oxide film can be reduced by the temper solution.The generated speed of oxide film is conducive to reduce the incidence of yellow spot defects.The addition of phosphate and molybdate can improve the generated speed of oxide film on the cold rolled plate surface.