X80管线钢在模拟土壤溶液中的阳极溶解特征

Anodic Dissolution Characteristics of the X80 Pipeline Steel in Simulated Soil Solution

应用动电位极化方法研究了X80管线钢在不同pH条件下模拟土壤局部环境NS4溶液中的阳极溶解特征，并通过极化曲线的解析得到电化学腐蚀参数。 X80管线钢在NS4溶液中具有活性阳极溶解特征，阳极过程为多步反应机制，局部溶液pH值和波动应力循环对阳极溶解的机制没有影响。当溶液pH值在3~7范围内，随着溶液pH值降低，阳极溶解电流密度增加，波动应力也促进阳极溶解过程。讨论了阳极溶解与管道近中性pH-SCC的关系，可为埋地管道近中性pH-SCC的控制提供参考。

Potentiodynamic polarization technique was adopted to investigate the anodic dissolution characteristics of X80 pipeline steel in a simulated localized soil environment,which is NS4 solution. Electrochemical corrosion parameters were obtained by resolving polarization curves. The corrosion of the X80 pipeline steel is characteristic of active anodic dissolution,and the anodic process includes several multi-step reaction mechanisms. The pH-value of the NS4 solution and fluctuation cycle stress have no effect on the mechanism of anodic dissolution. The corrosion current density increases when the value of pH decreases in the range between 3 and 7. Fluctuation stress also enhances the anodic dissolution. The correlation between anodic dissolution and near-neutral pH-SCC was discussed. These can provide a reference for controlling the near-neutral pH-SCC of pipes buried in soil.