RPV钢在辐照和温度作用下的细观力学行为研究

项目名称： RPV钢在辐照和温度作用下的细观力学行为研究

项目编号： No.11202114

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 聂君锋

作者单位： 清华大学

项目金额： 25万元

中文摘要： 核反应堆压力容器（RPV）钢的断裂失效与中子辐照、温度以及材料的微观结构密切相关。本项目拟采用试验、理论和计算相结合的方法，从位错运动引起的材料塑性行为出发，建立基于热激活机制的、反映位错运动的晶体塑性本构模型，考虑辐照效应和温度影响，体现RPV钢的微结构演化形态，来研究RPV钢在辐照和温度作用下的力学行为。首先，需要发展改进应用于RPV钢的晶体塑性本构模型，通过优化算法得到材料参数；进一步，研究RPV钢的微结构对力学行为的影响，重点考察晶粒大小、晶向以及织构等的作用，研究尺度效应、各向异性和变形非均匀性，并且考虑由于辐照引起的微结构的演化，对RPV钢力学行为的影响；最后，从微观角度研究RPV钢在辐照和温度作用下的失效机制和韧脆转变机制，建立晶粒损伤和沿晶界破坏的竞争机制；通过热激活理论判据，从温度和辐照两个方面研究RPV钢的韧脆转变机制，找出在辐照情况下，韧脆转变温度的变化。

中文关键词： 晶体塑性；辐照效应；位错密度；尺寸效应；应变梯度

英文摘要： Fracture failure of the reactor pressure vessel (RPV) steels is strongly related to the neutron irradiation, temperature and the microstructure of material. Ihis project intends to use a combination methods of experiment, theory and numerical calculation. From the plastic behavior of material caused by the movement of the dislocation, a crystal plasticity constitutive model is established based on thermal activation mechanism, which can take into account irradiation effects and temperature effects, and reflect the evolution morphology of RPV steel microstructure. This model is used to study the mechanical behavior of RPV steels under irradiation and temperature effects. In this project, firstly, the crystal plastic constitutive used for RPV steel should be developed and improved, in which the flow and hardening parameters are obtained by optimization algorithm. Secondly, the effect of RPV steel microstructure on the mechanical behavior is researched, and the emphasis is on the grain size, crystal orientation and texture. In this section, scale effect, anisotropy and non-uniform deformation of mechanical behavior of the RPV steel are studied, and the effect of the evolution of microstructure caused by irradiation on the mechanical behavior is also considered. Finally, from microscopic view, the failure mechanism

英文关键词： Crystal plasticity；irradiation effect；dislocation density；size effect；strain gradient