中国物理B ›› 2016, Vol. 25 ›› Issue (11): 116801-116801.doi: 10.1088/1674-1056/25/11/116801

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

First-principles study of He trapping in η-Fe2C

Bing-Ling He(赫丙玲), Jin-Long Wang(王金龙), Zhi-Xue Tian(田之雪), Li-Juan Jiang(蒋利娟), Wei Song(宋薇), Bin Wang(王斌)   

  1. 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
  • 收稿日期:2016-06-02 修回日期:2016-08-07 出版日期:2016-11-05 发布日期:2016-11-05
  • 通讯作者: Bing-Ling He E-mail:hbl626@126.com
  • 基金资助:
    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) and the Innovation Talents Program of Science and Technology of Institution of Higher Education of Henan Province, China (Grant No. 14HASTIT044).

First-principles study of He trapping in η-Fe2C

Bing-Ling He(赫丙玲)1, Jin-Long Wang(王金龙)1, Zhi-Xue Tian(田之雪)2, Li-Juan Jiang(蒋利娟)1, Wei Song(宋薇)1, Bin Wang(王斌)1   

  1. 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
  • Received:2016-06-02 Revised:2016-08-07 Online:2016-11-05 Published:2016-11-05
  • Contact: Bing-Ling He E-mail:hbl626@126.com
  • Supported by:
    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) and the Innovation Talents Program of Science and Technology of Institution of Higher Education of Henan Province, China (Grant No. 14HASTIT044).

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摘要： 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.

关键词: He bubble, η-Fe2C, ferritic steels, first-principles

Abstract: 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.

Key words: He bubble, η-Fe2C, ferritic steels, first-principles

中图分类号:  (Nucleation and growth)

  • 68.55.A-
71.15.Mb (Density functional theory, local density approximation, gradient and other corrections) 71.15.Nc (Total energy and cohesive energy calculations)