用AES和EPMA研究Fe-Cr合金钝化膜和蚀孔内壁的组成特征

采用 AES 和 EPMA 对三种 Fe-Cr 合金在3.5%NaCl 溶液中的钝化膜以及点蚀孔的内壁进行了分析,由 Ar~+溅射得到了 Cr~+/Fe 比随深度变化的分布,考察了铬在钝化膜中的作用.通过实验和分析证明:Fe-Cr 合金表面钝化膜和点蚀孔内壁的 Cr/Fe 比都明显高于基体的 Cr/Fe 比,决定钝化膜性能的重要因素是 Cr/Fe 比,并且 Cr/Fe 比越高,钝化膜的保护性越好。

THR AES AND EPMA STUDY OF PASSI VE FILM AND PIT SIDEWALL OF Fe--Cr ALLOYS

AES and EPMA have been used to study the passive film and the pit sidewall of Fe-Cr alloys which contain 13%,17% and 28%Cr in 3.5%NaCl solution.By Ar~+ sputtering,the Cr/Fe ratio versus the thickness of the passive film is obtained,and the behavior of Cr in the film has beeninves- tigated.Experiments and analyses show that the Cr/Fe ratio both in the surface passive film and in the pit sidewall of Fe-Cr alloys are markedly higher than that of base materials.The most important factor withregard to protective ability of the passive film is the Cr/Fe ratio in thefilm.The higher the Cr/Fe ratio,the better the protective ability of thefilm is.