合金元素(Cr、Ni、Mn、Cu)增强T91钢耐蚀性机理的第一性原理计算研究  

Research on the Mechanism of Enhancing the Corrosion Resistance of T91 Steel with Alloying Elements(Cr,Ni,Mn,Cu)Based on First-Principles Calculations

作　　者：叶怀波 孙琨[1] 李六六 吴冰洁 YE Huaibo;SUN Kun;LI Liuliu;WU Bingjie(State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,Xi’an 710049,China;Nuclear Power Institute of China,Chengdu 610005,China)

机构地区：[1]西安交通大学金属材料强度国家重点实验室,西安710049 [2]中国核动力设计研究院,成都610005

出　　处：《西安交通大学学报》2024年第9期205-212,共8页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(52075417)。

摘　　要：为解决核反应堆结构材料T91钢在铅铋合金液中耐腐蚀性低的问题,采用热力学模拟和第一性原理计算相结合的方法,在原子尺度上探究了合金元素Cr、Ni、Mn、Cu增强T91钢的耐腐蚀性能的机理。通过热力学模拟计算研究,确定了T91钢室温下的主要相成分为马氏体结构,搭建了4种第一性原理计算模型马氏体-铬模型、马氏体-镍模型、马氏体-锰模型以及马氏体-铜模型,并计算比较了电子结构以及电荷密度分布,发现合金元素与Fe原子之间形成金属键。通过差分电荷研究分析,发现Cr与Fe原子之间的金属键具有较强的共价键特性且结合最强,Ni与Fe原子之间的金属键也具有一定的共价键特性,但其结合弱于Cr、Cu和Mn原子次之。同时,计算了4种模型中合金元素与基底之间的结合能,发现马氏体-铬模型不仅能量最低,而且Cr与基底的结合很高,说明Cr原子能够提高T91钢的耐腐蚀性能。该研究可为合金元素Cr、Ni、Mn、Cu增强T91钢耐铅铋合金液腐蚀性能提供参考,同时也为新材料的开发以及性能预测提供一种新的研究方法。To address the problem of low corrosion resistance of T91 steel,a structural material used in nuclear reactors,in lead-bismuth alloy liquid,this paper employs a combination of thermodynamic simulation and first-principles calculations to investigate the mechanism of enhancing the corrosion resistance of T91 steel at the atomic scale with alloying elements Cr,Ni,Mn and Cu.Through thermodynamic simulation calculations research,the main phase composition of T91 steel at room temperature is determined to be martensite,and four first-principles calculation models,namely martensite-Cr,martensite-Ni,martensite-Mn,and martensite-Cu,are established and used to calculate and compare electronic structure and charge density distribution.It is found that a metallic bond is formed between the alloying elements and Fe atoms.Differential charge studies show that the metal bond between Cr and Fe atoms has strong covalent bond characteristics and the strongest bonding,while the metal bond between Ni and Fe atoms also has certain covalent bond characteristics,but its bonding is weaker than Cr,followed by Cu and Mn atoms.Additionally,the binding energy between the alloying elements and the substrate in the four models is calculated,with the martensite-Cr model exhibiting the lowest energy and a strong binding between Cr and the substrate.This effectively demonstrates that Cr atoms can improve the corrosion resistance of T91 steel.Overall,this study provides valuable insights for enhancing the corrosion resistance of T91 steel to lead-bismuth alloy using Cr,Ni,Mn and Cu,and also presents a novel research method for the development and performance prediction of new materials.

关 键 词：T91钢 耐腐蚀性能 第一性原理计算 合金元素 

分 类 号：TB31[一般工业技术—材料科学与工程]