锌铝镁镀层钢板前处理与电泳性能研究

Study on pretreatment and electrophoresis performance of Zn–Al–Mg alloy coated steel sheet

以镀锌钢板作为对比,考察锌铝镁钢板涂装前处理和电泳性能。结果显示:锌铝镁钢板的脱脂性能与镀锌钢板相近,磷化膜外观、膜重、覆盖率和结晶尺寸与镀锌钢板差异较小,电泳漆膜外观、膜厚、附着力和耐冲击性与镀锌钢板一致,但电泳漆膜的杯突极限性能和划线循环腐蚀性能优于镀锌钢板。

The properties of Zn–Al–Mg alloy coated steel sheet after pretreatment and electrophoresis prior to painting were studied and compared with the Zn-coated steel sheet.The results showed that the degreasability of Zn–Al–Mg alloy coated steel sheet is similar to that of Zn-coated steel sheet.The appearance,deposition mass per unit area,coverage,and crystal size of phosphating film on Zn–Al–Mg alloy coated steel sheet are less different from those on Zn-coated steel sheet.The appearance,thickness,adhesion,and impact resistance of the electrophoretic coating on Zn–Al–Mg alloy coated steel sheet are consistent with that on Zn-coated steel sheet.The electrophoretic coating on Zn–Al–Mg alloy coated steel sheet showed better performance in the cupping test under an extreme condition and in the cyclic corrosion test after being scratched than that on Zn-coated steel sheet.