采用腐蚀电位分析和电化学阻抗技术研究了经钝化的镀锌钢在不同浓度的NaCl溶液中的腐蚀行为. 结果表明, 镀锌钝化层在NaCl溶液中的腐蚀分为三个阶段: 钝化膜的溶解、镀锌层的阴极保护和钢基体的腐蚀. 浸泡初期主要受Cl-浓度影响, 且浓度越高腐蚀越严重; 浸泡中期, 随着Cl-浓度增加镀锌层耐腐蚀性能先减小后增大, 在5% NaCl溶液中耐腐蚀性最差.
The corrosion behavior of a galvanized steel after passivation treatment in NaCl solution was investigated by measurements of corrosion potential and electrochemical impedance spectra (EIS). The results indicated that there were three stages for corrosion of the galvanized steel in NaCl solution i.e. dissolving of the passive film, anodic corrosion of zinc plating and then corrosion of the substrate steel. During the initial stage of immersion in NaCl solution, the behavior of the galvanized steel after passivation was affected by the content of Cl-, the higher of the Cl- content, the much serious was the corrosion of the galvanized steel. With the extension of the immersion time, the corrosion resistance of the galvanized steel firstly decreased and then increased with the increasing Cl- content. The galvanized steel after passivation showed the poorest corrosion resistance in 5% NaCl solution.