辐照诱导RPV钢中磷的偏析及对材料脆化行为影响的多尺度模拟研究

项目名称： 辐照诱导RPV钢中磷的偏析及对材料脆化行为影响的多尺度模拟研究

项目编号： No.51201184

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 金属材料学科

项目作者： 贺新福

作者单位： 中国原子能科学研究院

项目金额： 25万元

中文摘要： 最近大量加速辐照实验数据表明，当辐照到相当于核电站60-80年寿期中子注量时，辐照诱导磷（P）的晶界偏析所导致的RPV钢非硬化致脆是RPV钢的主导脆化因素之一，但到目前为止关于RPV钢中辐照诱导P的晶界偏析机理以及P的偏析对RPV钢脆化机理的影响还没弄清。本课题拟采用多尺度模拟方法，在已有的大量实验数据基础上采用多尺度模拟方法针对高注量中子辐照下RPV钢（A508-III钢、VVER）中P的晶界偏析机理、P的偏析对RPV钢ΔDBTT的影响开展理论研究，建立高注量中子辐照诱导RPV钢中P的晶界偏析物理模型、高注量中子辐照下P的偏析对RPV钢脆化机理影响物理模型，探讨影响P晶界偏析的主导因素以及P的偏析物所导致的非硬化致脆机理，在此基础上预测相当于80年寿期时P的偏析量以及RPV钢的脆化程度，以期为核电站的延寿提供技术支持。

中文关键词： 压力容器；磷的晶界偏析；辐照；多尺度模拟；脆化

英文摘要： The embrittlement of Reactor Pressure Vessel (RPV) steels is in general thought to be caused primarily by 1) the formation of Cu-enriched clusters, 2) the formation of matrix damage features, and 3) the segregation of phosphorus atoms at grain boundaries. The segregation of P atoms at grain boundaries may weaken the strength of grain boundary bonding so that fracture occurs preferentially at grain boundaries. Thus, embrittlement due to P segregation is called non-hardening embrittlement. At present, P segregation has been identified in RPV materials such as A533B,A508-III and VVER steels used in many reactors in worldwide, but the effect of P segregation on the grain boundary fracture is not well understand until now.Now it is believed that harding of the matrix by precipitates rich in copper is the basic mechanism of RPV steel embrittlement in PWRs and VVERs at moderate dose.Recent research shows that, as neutron fluences increases, the fraction of intergranular fracture(IGF) in VVER base steels increases to 80% and irradiation-induced P coverage at grain boundaries approaches 45% of a monolayer. Similar increase are seen in PWR materials. These results suggest that the additional non-hardening intergranular segregation mechanism of irradition embrittlement becomes more importmant in these RPV steels at higher

英文关键词： Reactor Pressure Vessel；Phosphorus segregation；irradiation；multiscale modeling；embrittlement