文献类型：期刊文献

中文题名：First-principles study of He trapping in η-Fe_2C

英文题名：First-principles study of He trapping in η-Fe2C

作者：He, Bing-Ling[1]; Wang, Jin-Long[1]; Tian, Zhi-Xue[2]; Jiang, Li-Juan[1]; Song, Wei[1]; Wang, Bin[1]

第一作者：赫丙玲

通讯作者：He, Bing-Ling

机构：[1] College of Physics and Electronic Engineering, Xinxiang University, Xinxiang, 453003, China; [2] College of Physics and Information Engineering, Hebei Normal University, Shijiazhuang, 050024, China

第一机构：新乡学院物理与电子工程学院

年份：2016

卷号：0

期号：11

中文期刊名：中国物理B：英文版

外文期刊名：Chinese Physics B

收录：CSTPCD;;EI(收录号：20164803050548);Scopus(收录号：2-s2.0-84995938562);CSCD:【CSCD2015_2016】；

基金：Project supported by the Research Key Project of Science and Technology of Education Bureau of Henan Province,China(Grant Nos.14A140030,15A140032,15B150010,and 15A430037);the Innovation Talents Program of Science and Technology of Institution of Higher Education of Henan Province,China(Grant No.14HASTIT044)

语种：英文

中文关键词：He bubble;η-Fe2C;ferritic steels;first-principles

外文关键词：Binding energy - Diffusion barriers - Ferrite - Ferritic stainless steel

摘要：The distribution of He in η-Fe_2C has been studied by first-principles calculations.The formation energies of interstitial He and substitutional He(replacing Fe) are 3.76 eV and 3.49 eV,respectively,which are remarkably smaller than those in bcc Fe,indicating that He is more soluble in η-Fe_2C than in bcc Fe.The binding potencies of both a substitutionalinterstitial He pair(1.28 eV) and a substitutional-substitutional He pair(0.76 eV) are significantly weaker than those in bcc Fe.The binding energy between the two He atoms in an interstitial-interstitial He pair(0.31 eV) is the same as that in bcc Fe,but the diffusion barrier of interstitial He(0.35 eV) is much larger than that in bcc Fe,suggesting that it is more difficult for the interstitial He atom to agglomerate in η-Fe_2C than in bcc Fe.Thus,self-trapping of He in η-Fe_2C is less powerful than that in bcc Fe.As a consequence,small and dense η-Fe_2C particles in ferritic steels might serve as scattered trapping centers for He,slow down He bubble growth at the initial stage,and make the steel more swelling resistant.
The distribution of He in η-Fe2C has been studied by first-principles calculations. The formation energies of interstitial He and substitutional He (replacing Fe) are 3.76 eV and 3.49 eV, respectively, which are remarkably smaller than those in bcc Fe, indicating that He is more soluble in η-Fe2C than in bcc Fe. The binding potencies of both a substitutional-interstitial He pair (1.28 eV) and a substitutional-substitutional He pair (0.76 eV) are significantly weaker than those in bcc Fe. The binding energy between the two He atoms in an interstitial-interstitial He pair (0.31 eV) is the same as that in bcc Fe, but the diffusion barrier of interstitial He (0.35 eV) is much larger than that in bcc Fe, suggesting that it is more difficult for the interstitial He atom to agglomerate in η-Fe2C than in bcc Fe. Thus, self-trapping of He in η-Fe2C is less powerful than that in bcc Fe. As a consequence, small and dense η-Fe2C particles in ferritic steels might serve as scattered trapping centers for He, slow down He bubble growth at the initial stage, and make the steel more swelling resistant. ? 2016 Chinese Physical Society and IOP Publishing Ltd.