反应堆压力容器( RPV) 在运行过程中长期暴露于辐照环境之下，中子辐照促进钢中的微量杂质Cu以细小的富铜原子团簇析出，导致压力容器钢及其焊缝区的局部脆化/老化，这种富铜团簇析出是影响反应堆运行寿命的关键因素之一。本研究采用原子尺度模拟方法模拟计算了Fe-Cu-Ni三元合金中，在不同局域原子环境下，Cu、Ni合金原子在BCC-Fe基体中的相关特征能量数据，以及空位与Cu、Ni的结合能；然后在第二近邻短程范围内的双体作用假设下，用键对能量模型分别描述了各特征能量的方程形式，采用最小二乘法，对键对能进行了拟合求解，得到键对能量数据，获取了常见缺陷复合体的能量数据；最后按照Kinetic Ising激活能模型计算出Le Claire模型下，含有杂质元素情况下的空位激活能。分析比较各路径激活能得出：RPV钢中Cu原子对空位有较强吸附能力，再考虑到Cu元素在BCC-Fe中极低的固溶度，将使Cu原子在Fe基体中容易形成团聚，符合实验结论。6970
关键词  RPV钢  Fe-Cu-Ni三元合金   富铜团簇   分子静力学   键对能
毕业设计说明书（论文）外文摘要
Title  Simulation study on the features of point defects in nuclear reactor steel
Abstract
The reactor pressure vessel (RPV) exposures to long-term neutron irradiation during operation. Copper precipitation in the form of copper-rich atomic clusters is accelerated by neutron irradiation, which contributes to increasing brittleness of pressure vessel steel, and the welded joint as well. Embrittlement of the RPV caused by This kind of precipitation is one of the key factors to the operational life of the reactor. This work using atomic-scale simulation, eg. Molecular Statics (MS) to study the Fe-Cu-Ni ternary alloy, characteristic energies of Cu and Ni atoms under different local environment and the vacancy binding energies with Cu and Ni was calculated. Then under pairwise two-body interaction and second nearest neighbor cut-off range assumption, characteristic energy datas were fitted to the broken-bond energy model using a least squares method in order to describe energy of defects complexes. The activation energies of vacancy around a impurity atom according to the Le Claire model was calculated to verify the fitted bond energies with the Kinetic Ising activation energy model. Result shows the vacancies has a trapping effect around Cu atom, taking into account the very low solid solubility of Cu in the BCC-Fe, Cu atoms has the tendency to precipitate, which fit the experiments well.
Keywords  RPVsteel  Fe-Cu-Ni ternary alloy  copper-rich clusters  Molecular Statics  broken-bond model  
目录
1. 绪论    1
1.1 反应堆压力容器钢的辐照脆化效应    1
1.2富铜团簇的形成机理    2
1.3点缺陷与富铜团簇析出    3
1.4 RPV钢中富铜团簇析出的研究方法    4
1.4.1 实验研究方法    4
1.4.2 模拟研究方法    5
2. 研究内容和目的    8
3. 研究方法    9
3.1 长程多体势函数    9
3.2 分子动力学（MD）和分子静力学（MS）    10
3.3 本研究中模型的构建    11
4. 研究结果    16
4.1 特征能量的模拟计算    16
4.2 键对能的拟合    19
5. 结论    23
致  谢    24
参 考 文 献    25
1. 绪论
核电站反应堆的类型很多，目前已经商业化的核电站主要有压水堆、沸水堆和重水堆等堆型。其中压水堆在技术上比较成熟，是核电站系列化、大型化和商品化最多的堆型，它是一种冷却水保持在不发生整体沸腾压力(14-16MP)之下的热中子反应堆，占在建核电厂反应堆总数的67.5％和核电总功率的74.1％，其次是沸水堆和重水堆[1]。 核反应堆用钢中点缺陷跃迁特性的模拟研究:http://www.751com.cn/cailiao/lunwen_4717.html