室温注氢Fe-Cr合金在不同温度退火后位错环的表征  

Characterization of dislocation loops in hydrogen ion-implanted Fe-Cr alloy annealed at different temperatures

作　　者：杜玉峰 崔丽娟 万发荣[1] DU Yu-feng;CUI Li-juan;WAN Fa-rong(School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学材料科学与工程学院

出　　处：《工程科学学报》2019年第8期1016-1028,共13页Chinese Journal of Engineering

基　　金：国家自然科学基金资助项目(51471026)

摘　　要：利用透射电子显微镜,通过构建位错环在不同晶带轴下的投影图结合位错环消光判据,对室温注氢后Fe-9%Cr模型合金在400、500及550℃退火形成的1/2〈111〉和〈100〉两种类型的位错环进行了表征.实验结果表明,室温注氢Fe-9%Cr合金中柏氏矢量为〈100〉型位错环的数量随着退火温度的升高而逐渐增加.在400和500℃退火后,〈100〉型位错环所占比例分别为16.48%、92.78%;当退火温度升高到550℃时,位错环全部转变为〈100〉型位错环.Fe-9%Cr合金中位错环类型转变温度区间为400~500℃,与纯铁相比,添加Cr元素能够使位错环类型转变温度升高.Reduced-activation ferritic/martensitic(RAFM)steels,based on Fe-Cr alloys,have been considered to be one of the most promising candidate structural materials for future fusion reactors.Dislocation loops,as one of the most common microstructures induced by radiation,are the key factors in the deterioration of material properties.Dislocation loops with different Burgers vectors have different effects on material properties.Currently,a consensus exists suggesting that there are two kinds of dislocation loops with Burgers vectors of 1/2〈111〉and〈100〉in bcc iron-based alloys.In this study,the Burgers vectors of dislocation loops formed at the annealing temperatures of 400,500,and 550℃in hydrogen-ion implanted Fe-9%Cr model alloy were examined based on dislocation loop maps and dislocation loop invisibility criteria.Dislocation loop maps manifest such that under the〈100〉or〈110〉zone axes,it is easy to distinguish 1/2〈111〉and〈100〉edge dislocation loops,while under the〈111〉zone axis,the loops cannot be distinguished.By direct comparison between loop maps and loop images obtained through transmission electron microscope(TEM),the dislocation loops with Burgers vectors of 1/2〈111〉and〈100〉,formed at different annealing temperatures,were characterized.The results of the characterization show that with increasing annealing temperature,the size of the dislocation loops increases while density decreases.Furthermore,the proportion of dislocation loops with a Burgers vector of〈100〉increases with rising temperature.After annealing at400℃and 500℃,the percentages of〈100〉type dislocation loops are 16.48%and 92.78%respectively,in hydrogen-ion implanted Fe-9%Cr alloy.While the temperature is raised to 550℃,all the dislocation loops are of〈100〉type loops.This indicates that the transition temperature range of dislocation loops in Fe-9%Cr is 400℃-500℃.Compared with pure iron,the presence of Cr element promotes the transition temperature of dislocation loops from 1/2〈111〉type to

关 键 词：FE-CR合金 氢离子辐照 退火温度 位错环类型 透射电镜 

分 类 号：TL627[核科学技术—核技术及应用]