文献类型：期刊文献

英文题名：First-Principles Study of Helium Trapping in Carbide Precipitates (Cr23C6) in Ferritic-Martensitic Steels

作者：Cao, Jin-Li[1];Xiao, Wei[2];Cao, Qi[1];He, Bing-Ling[3]

第一作者：Cao, Jin-Li

通讯作者：He, BL[1]

机构：[1]Univ Sci & Technol Beijing, Sch Mat Sci & Engn, Beijing 100083, Peoples R China;[2]Gen Res Inst Nonferrous Met, State Key Lab Nonferrous Met & Proc, Beijing 100088, Peoples R China;[3]Xinxiang Univ, Coll Phys & Elect Engn, Xinxiang 453003, Peoples R China

第一机构：Univ Sci & Technol Beijing, Sch Mat Sci & Engn, Beijing 100083, Peoples R China

通讯机构：[1]corresponding author), Xinxiang Univ, Coll Phys & Elect Engn, Xinxiang 453003, Peoples R China.|[110717]新乡学院物理与电子工程学院;[11071]新乡学院;

年份：2018

卷号：74

期号：3

起止页码：177-185

外文期刊名：FUSION SCIENCE AND TECHNOLOGY

收录：;EI(收录号：20182405299193);Scopus(收录号：2-s2.0-85048121740);WOS:【SCI-EXPANDED(收录号:WOS:000444421600001)】；

基金：Jin-Li Cao is grateful to her advisor Wen-Tong Geng for his guidance in carrying out this research. This work was supported by the National Magnetic Confinement Fusion Program of China (grants 2014GB104003 and 2015GB105001) and the National Natural Science Foundation of China (grants 51504033 and 11704041).

语种：英文

外文关键词：He bubble; Cr23C6; first principles

摘要：Experiments observed preferential He bubble formation in carbide precipitates M23C6 during low-temperature He irradiation in ferritic-martensitic steels. However, the process and mechanism of He trapping in M23C6 present a challenge to measure. Using density functional theory, we have systematically investigated He distribution, migration, and accumulation in Cr23C6. The formation energies of interstitial and substitutional He in Cr23C6 are 3.50 and 3.16 eV, respectively, remarkably lower than those in Fe matrix. The higher solubility of He in Cr23C6 makes it an He-trapping center in martensitic steels. On the other hand, the migration barrier of interstitial He in Cr23C6 is 2.58 eV, about 2.52 eV higher than that in bulk Fe. Furthermore, we only find a very weak attraction potency for substitutional-interstitial He pair, 0.25 eV, and even no binding trend for interstitial-interstitial or substitutional-substitutional He pairs, which suggests that it is more difficult for He atoms to move and less powerful driving force to accumulate in Cr23C6 than those in Fe matrix. Our results indicate that the trapping effect results from a lower charge density zone in Cr23C6, and predict that the small and dense Cr23C6 particles may hinder bubble growth at the initial stage, which can improve the resistance to irradiation void swelling.