热轧酸洗板SAPH370表面色差成因探究及工艺优化

Study on the Cause of Surface Color Difference of Hot-rolled Pickling Plate SAPH370 andProcess Optimization

针对热轧酸洗板SAPH370表面出现的板宽方向色差缺陷,通过光学显微镜、扫描电镜分析色差缺陷热轧基板氧化铁皮结构、氧化铁皮厚度及酸洗后微观形貌,由此得出带钢表面粗糙度差异是造成表面色差的直接原因。结合热轧工序冷却速率与氧化铁皮产生机理可知,板宽方向色差主要是沿板宽方向的热轧氧化铁皮厚度和氧化铁皮结构差异造成了酸洗后不同位置酸洗程度不同,从而导致表面粗糙度差异。通过优化热轧卷取温度、下线后冷却速度、轧制温度等控制措施,可以有效消除色差缺陷。

According to the color difference defect on the surface of hot-rolled pickling plate SAPH370,the structure,thickness and morphology of the oxide sheet after pickling of the hot-rolled substrate with color difference defect were analyzed by optical microscope and scanning electron microscope.Combined with the cooling rate of hot rolling process and the mechanism of oxide sheet production,it can be seen that the color difference in the wide direction of the plate is mainly caused by the difference in the thickness and structure of the oxide sheet along the wide direction of the plate,which leads to the difference in the degree of pickling at different positions,resulting in the difference in surface roughness.Color difference defects can be effectively eliminated by optimizing hot rolling coiling temperature,cooling speed after rolling off line and rolling temperature.