用浸泡试验、电化学阻抗技术和扫描电镜(SEM)研究比较了汽车镀锌板及基板在不同Cl^-含量鹰潭泥浆中的腐蚀行为。结果表明:在实验介质条件下,镀锌板和IF钢(无间隙原子钢,有时也称超低碳钢)基板均发生了明显的腐蚀,镀锌板的腐蚀速率普遍高于基板;泥浆中的Cl^-含量对腐蚀行为有较大影响,镀锌板在5%Cl^-的泥浆中腐蚀速率最大,基板在1%Cl^-泥浆中腐蚀速率最大;腐蚀产物的致密性影响其保护性能,Cl^-通过影响泥浆中的溶氧量和腐蚀产物的保护性综合影响金属在泥浆中的腐蚀行为;腐蚀电位和电化学阻抗测量的分析结果与实际腐蚀速率具有很好的对应性,反映了腐蚀随时间变化的电极表面特性。
Corrosion behavior of the galvanized auto steel sheet and the substrate in the mud containing different contents of Cl^- was investigated and compared by the immersion test, electrochemical impedance spectroscopy (EIS) analysis and SEM observation. Under the experimental conditions apparent corrosion for both materials have took place and the corrosion rate of the galvanized steel sheet was normally higher than that of the substrate. The content of Cl^- in the mud had a significant effect on the corrosion behavior, the highest corrosion rate for the galvanized steel sheet was in the 5% Cl^- mud and for the substrate in the 1% Cl^-mud, respectively. The compactness of corrosion products decided their protection property and the Cl^- ions affected the corrosion behavior of metals through influencing the dissolved oxygen in the mud and the protection property of corrosion products. The analysis results of corrosion potential and EIS were quite consistent with the corrosion rates, reflecting the change of electrode properties with time during corrosion.