316LN在含Cl^-、NO_3^-环境中的腐蚀规律研究

Study on Corrosion Behaviors of 316LN Steel in Acid Solution Containing Cl^- and NO_3^-

通过极化曲线、阻抗谱及循环极化曲线等电化学测试方法研究不同酸性介质中Cl^-与NO_3^-对316LN腐蚀规律的影响。结果表明,随着Cl^-的减少和NO_3^-的增加,316LN的钝化区间变宽,维钝电流减小,腐蚀速率降低,膜层间电荷传递电阻增大,腐蚀阻力增加,耐蚀性增强。Cl^-破坏钝化膜,NO_3^-促进钝化膜的形成和修复,并对两种离子的作用机理进行了解释。

The electrochemical testing methods like polarization curves and impendence spectroscopy and cy- clic polarization curves were adopted for the investigation of the influence of CI and NO3- of various acid medi- um on the corrosion behaviors of 316LN. The resuhs show that with the decrease of CI- and the increase of NO3-, the corrosion rate of 316LN decreases along with smaller passive current and wider passive region. With the increase of charge transfer resistance, the corrosion resistance of 316LN increases. CI can destroy the pas- sive film while NO3 accelerates the formation of passive film. The effects of CI and NO3- were analyzed.