利用扫描电镜、波纹度仪、电化学测试系统等试验设备, 研究了不同表面粗糙度对冷轧钢板磷化质量的影响。结果表明, 冷轧钢板表面粗糙度对冷轧钢板的磷化质量影响较大, 提高冷轧钢板表面粗糙度有利于降低冷轧钢板的表面活性, 进而有利于提高冷轧钢板的磷化质量; 将冷轧钢板表面粗糙度的Ra控制在0.75~0.95 μm、RPc值控制在60~80峰个数/cm后, 冷轧钢板的磷化质量得到明显改善, 磷化膜的结晶状态由原来的磷化膜晶粒粗大变得细小, 磷化膜晶粒由不均匀、不致密变得均匀、致密; 膜重由改进前的1.59 g/m2升高到2.24 g/m2; 磷化膜的防锈能力也有了一定的提高, 磷化膜涂漆后500 h盐雾试验的划伤部分扩散宽度由改进前的6 mm下降到2.5 mm。

The influence of surface roughness of cold-rolled steel sheet on the quality of phosphate coating was studied by SEM, roughness meter and M398 electrochemical measure system. The results showed that the roughness strongly affected the quality of phosphate layer. The activity of the cold-rolling steel sheet was lowered when the roughness increased, and thus the quality of phosphate layer was improved. When Ra was between 0.75~0.95 μm, RPc was between 60~80 PC/cm, the grain size was small, the phosphate layer was uniform, the coating weight was improved from 1.59 g/m2 to 2.24 g/m2. The anti-corrosion ability was improved, the corrosion width of the rip of painted steel sheet with phosphate layer was decreased from 6mm to 2.5 mm.