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采用X射线光电子能谱（XPS）研究了AISI304不锈钢在含（MoO42-+Cl-）的模拟闭塞电池中形成钝化膜的组成与结构及MoO42-抑制局部腐蚀的机理.结果表明:在闭塞区内AISI304不锈钢表面钝化膜的外层主要有MoO42-、CrO3、CrCl3、CrOOH、Fe2O3、γ-FeOOH、Fe（OH）3、CrO42-、Cr（OH）3、NiCl2、FeCl2和FeCl3、溅射5min时膜内层主要有 MOCl3、CrO2、FeCl2、FeCl3以及少量的FeO.MoO42-对钝化膜的影响在于:MoO42-迁入闭塞区后吸附在金属表面上,可取代或部分取代吸附在钢表面的Cl-,并与Fe2+在蚀孔内反应生成不容性的FeMoO4而沉积到蚀孔壁上,有助于蚀孔的再钝化,从而抑制腐蚀的进一步扩展;MoO42-的吸附能使水合氧化亚铁沉淀膜由阴离子选择性变为阳离子选择性,使H+可以从膜下扩散出去,而Cl-难以扩散到膜下富集,从而使MoO42-具有缓蚀作用。
X-ray photoelectron spectroscopy (XPS) was used to study the composition and structure of the passivation film and the MoO42-inhibiting local corrosion mechanism of the AISI304 stainless steel in the MoO42- + Cl-occluded cells. The results show that in the occluded area The outer layer of the inner surface passivation film of AISI304 stainless steel is mainly composed of MoO42-, CrO3, CrCl3, CrOOH, Fe2O3, γ-FeOOH, Fe (OH) 3, CrO42-, Cr (OH) 3, NiCl2, FeCl2 and FeCl3, 5min when the inner membrane mainly MOCl3, CrO2, FeCl2, FeCl3 and a small amount of FeO.MoO42- on the passivation film is affected: MoO42-moved into the occlusion zone after adsorption on the metal surface, can replace or partially replace the adsorption in the steel Surface Cl- and react with Fe2 + in the etching hole to form incongruent FeMoO4 to deposit on the wall of the etching hole, which contributes to the re-passivation of the etching hole, thereby inhibiting the further expansion of corrosion; the adsorption of MoO42- The precipitation of Fe 2 O 3 from anion to cation is selective, allowing H + to diffuse out of the membrane and Cl- to diffuse below the membrane to enrich, leaving MoO42- with corrosion inhibition.