316L和316LN不锈钢在高温高盐溶液中钝化膜的性能研究

摘要

利用电化学及扫描电子显微镜(SEM)对316L与316LN两种不锈钢在高温高盐环境中的耐蚀性能进行了对比研究,利用Mott-Schottky曲线研究了两种材料的钝化膜半导体特征,借助X射线光电子能谱(XPS)研究了316LN不锈钢的钝化膜结构以及N元素在钝化膜中的分布状态.结果表明:在高温高盐环境中,两种材料形成的钝化膜都为n型半导体;316LN不锈钢形成的钝化膜耐点蚀性能更好,其钝化膜内缺陷浓度更低,N元素会在钝化膜中富集.最后利用点缺陷原理对316LN钝化膜的耐蚀机理进行了研究.%The passive films formed on 316L and 316LN stainless steel in high-temperature and high-salinity solution have been investigated by electrochemical measurements and surface analysis methods.The results show that the passive films formed on both 316L and 316LN stainless steel behave as n-type semiconductors,but the passive film formed on 316LN stainless steel has lower donor density and better anti-pitting properties.X-ray photoelectron spectroscopy (XPS) show N enrichment in the passive films,and the anti-pitting mechanism of the 316LN stainless steel passive film is discussed using a point defect model.