Fe-Cr合金表面双层钝化膜离子迁移行为的第一性原理研究

项目名称： Fe-Cr合金表面双层钝化膜离子迁移行为的第一性原理研究

项目编号： No.51301200

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 于浩波

作者单位： 中国石油大学（北京）

项目金额： 25万元

中文摘要： 不锈钢耐蚀性的优劣取决于钝化膜的稳定性，而钝化膜的稳定性受控于膜中离子的迁移和膜的组成结构。以往钝化膜生长的宏观模型主要针对单层氧化物钝化膜中的离子迁移，并且也不能解释合金元素及其阳离子的迁移对钝化膜结构的影响。基于第一性原理和分子动力学计算的原子模型是解决上述问题的有利工具。申请者前期计算了纯Cr金属钝化膜中的离子迁移行为，发现离子在内外层迁移的类型和速率决定了钝化膜的保护性。而对于合金，申请者认为，钝化膜稳态结构及保护性可能与不同离子（特别是金属阳离子）在钝化膜中迁移的动态平衡过程有关。因此，本项目将以Fe-Cr二元合金钝化膜为研究对象，根据成分和组成，构建双层钝化膜的原子结构模型，应用第一性原理与分子动力学相结合的方法计算离子在双层钝化膜中的迁移行为，分析合金元素及其阳离子的迁移对钝化膜结构的影响，阐明离子迁移与钝化膜稳态结构之间的动态平衡关系。

中文关键词： 双层钝化膜；空位迁移；扩散系数；第一性原理；

英文摘要： The corrosion resistant property of stainless steels is determined by the stability of passive film formed on their surface, whilst the stability of passive film is controlled by the migration of ions and its composition and structure. Previous macroscopic models for passive film growth mainly focused on the migration of ions in oxide single-layer passive film, these models also did not interpret the influence of alloying elements and the migration corresponding cations on the structure of passive films. The atomic model based on First-principles and Molecular Dynamics calculations is an effective method to dissolve above questions. Applicant have studied the migration behavior of ions in the passive film formed on metallic Cr by calculations, and found that migration types and migrations rates of ions which migrate in the inner and outer layer of passive film determine the protective property of film. As to alloys, applicant believed that the stable structure and protective property of passive film are related to the dynamic balance process of migrations of different ions especially cations in the film. Accordingly, passive film formed on Fe-Cr binary alloy will be studied in this project. The atomic structure model of double layer passive film will be established by analyzing its composition and structure; th

英文关键词： double layer passive film；vacancy migration；Diffusion coefficient；First-principles theory；