单机架可逆冷轧带钢表面黑点缺陷原因分析及控制措施

黑斑缺陷严重影响带钢产品的表面质量，针对某单机架可逆冷轧带钢表面黑点缺陷问题，采用取样分析、酸洗实验、乳化液分析、现场质量排查等方法，对其形成原因及控制方法进行了研究。结果表明：黑点缺陷呈毛絮状，向外发散，尺寸范围2～3 mm,打磨、酸洗后基本可以消除；黑点缺陷含质量分数约37%～40%的C元素，约23%的O元素，以及约35%～38%的Fe元素，属于锈蚀缺陷；排烟风机故障是造成黑点锈蚀的原因。提出了增加排烟风机运行与轧机运行的连锁控制、增加排烟管路烟气压力检测装置及报警功能、固定油雾排放系统清理周期，增加备件储存量等改进措施，黑点缺陷得到了有效控制。

Cause analysis and control measures of black spot defect on the sufure of cold rolled strip produced by single stand reversing rolling mill

The black spot defect seriously affects the surface quality of strip products. Aiming at the problem of black spot defecton the surface of cold rolled strip produced by single stand reversing rolling mill, the formation reason and control methods of the defect were studied by means of sampling analysis, pickling experiment, emulsion analysis and on-site quality inspection. The results show that the black spot defects are flocculent, diverging outwards, with a size range of 2-3 mm, and can be basically eliminated after polishing and pickling. The black spot defect contains about 37%-40% of C, about 23% of O and about 35%-38% of Fe, which belongs to corrosion defect. The smoke exhaust fan failure is the cause of black spot corrosion. The improvement measures such as increasing the interlock control of smoke exhaust fan operation and rolling mill operation,adding the smoke pressure detection device and alarm function of smoke exhaust pipe, fixing the cleaning cycle of oil mist emission system, and increasing the storage capacity of spare parts are proposed. The black spot defect has been effectively controlled.