摘要
现行标准体系中,Fe元素作为重水堆Zr-2.5Nb合金压力管中的杂质元素,含量上限受到严格控制。对已建成重水堆用Zr-2.5Nb合金压力管材料的堆内辐照试验表明,Fe元素含量较高会降低辐照生长及辐照蠕变导致的变形应变。归因于Fe元素对空位在α-Zr晶粒内的移动性的增强作用。空位的加速运动促进了空位<c>型位错环的形成,同时位错应力场的对称性减小了位错环的拉伸应变区。考虑到Fe元素在保障压力管堆形状稳定性方面的积极作用,在制订重水堆压力管用Zr-2.5Nb合金的技术条件时,除满足标准要求外,还应对Fe元素含量下限作出规定。
In the current standard system,Fe is an impurity element in Zr-2.5Nb alloy pressure tube of CANDU reactor,and its upper limit of content is strictly controlled.The in-reactor irradiation test of Zr-2.5Nb pressure tube used in the established water reactor shows that higher Fe element content reduces the deformation strain caused by irradiation growth and irradiation creep.This phenomenon is attributed to the enhanced mobility of vacancies inα-Zr grains by impurity Fe.The acceleration of vacancy promotes the formation of vacancy<c>-type dislocation loops,and the symmetry of dislocation stress field reduces the tensile strain region of dislocation loops.Considering the positive role of Fe element in ensuring the shape stability of pressure tube reactor,when formulating the technical conditions of Zr-2.5Nb alloy for CANDU reactor pressure tube,in addition to meeting the standard requirements,the lower limit of Fe element content should also be specified.
作者
严斌
赵冠楠
YAN Bin;ZHAO Guannan(Shanghai Nuclear Engineering Research&Design Institute Co.,Ltd.,Shanghai 200233,China)
出处
《有色金属材料与工程》
2021年第6期40-47,共8页
Nonferrous Metal Materials and Engineering
基金
上海核工程研究设计院业务建设课题(19yw016)。
