α-Fe材料辐照促进应力腐蚀开裂计算模拟研究

Simulation Study of Irradiation-Induced Stress Corrosion Cracking ofα-Fe

对于压水反应堆结构,辐照促进应力腐蚀开裂(IASCC)是其最主要的失效机制。理解辐照条件下辐照缺陷与微裂纹之间的相互作用,是理解辐照促进应力腐蚀开裂微观机制的重要一步。在本研究中,利用反应力场分子动力学(ReaxFF-MD)方法,模拟了体心立方结构(α相)的纯铁在辐照-应力-腐蚀三因素耦合作用下的演化过程,并对其进行腐蚀模拟与拉伸应变模拟,研究辐照促进应力腐蚀开裂底层物理机制及影响因素。

Irradiation induced stress corrosion cracking(IASCC)is the main failure mechanism of pressurized water reactor(PWR).Understanding the interaction between radiation defects and microcracks under irradiation conditions is an important step to understand the microscopic mechanism of stress corrosion cracking promoted by irradiation.In this study,the reaction field molecular dynamics(ReaxFF-MD)method was used to simulate the evolution process of pure iron with body-centered cubic structure(αphase)under the coupling action of irradiation,stress and corrosion,and corrosion simulation and tensile strain simulation were carried out to study the underlying physical mechanism and influencing factors of irradiation promoting stress corrosion cracking.