書誌事項
- タイトル別名
-
- First-Principles Calculation of Hydrogen Effects on the Formation and Diffusion of Vacancies in Alpha Iron: Discussion of the Hydrogen-Enhanced Strain-Induced Vacancy Mechanism
- スイソ ガ aテツ チュウ ノ クウコウ ノ セイセイ ト カクサン キョドウ ニ オヨボス エイキョウ ノ ダイイチ ゲンリ ケイサン : スイソ ジョチョウヒズミ ユウキ クウコウ キコウ ニ カンスル コウサツ
この論文をさがす
抄録
Hydrogen embrittlement is a well-known phenomenon in which hydrogen lowers the strength of materials. Despite extensive investigations, the role of hydrogen in materials remains unclear. Recently, Nagumo proposed the hydrogen-enhanced strain-induced vacancy model, which explains the reduction in the ductility of metals due to a significant increase in the vacancy concentration resulting from plastic deformation in a hydrogen environment. In the present study, we first estimated the interaction energy between hydrogen atoms and an atomic vacancy in alpha iron by applying density functional theory. We then estimated the mobility of an atomic vacancy in a hydrogen environment by calculating the activation energy for diffusion using the climbing image nudged elastic band method. These analyses showed that two hydrogen atoms are trapped by an atomic vacancy under a practical hydrogen gaseous environment (T = 300 K and p = 70 MPa). A reduction in the vacancy formation energy from 2.14 to 1.68 eV and an increase in the activation energy for vacancy diffusion from 0.62 to 1.07 eV by the hydrogen atoms were also observed. Jog dragging by a screw dislocation under shear stress was believed to be the mechanism for vacancy multiplication due to plastic deformation. Using the hydrogen-affected physical properties, we determined the vacancy distribution behind a jog moving at a constant velocity. This analysis suggested that supersaturated vacancies locally accumulate during plastic deformation in hydrogen environments.
収録刊行物
-
- 材料
-
材料 63 (2), 182-187, 2014
公益社団法人 日本材料学会
- Tweet
キーワード
詳細情報 詳細情報について
-
- CRID
- 1390001205443813632
-
- NII論文ID
- 130003393239
- 40019989765
-
- NII書誌ID
- AN00096175
-
- COI
- 1:CAS:528:DC%2BC2cXmslWkt7c%3D
-
- ISSN
- 18807488
- 05145163
-
- NDL書誌ID
- 025290841
-
- 本文言語コード
- ja
-
- データソース種別
-
- JaLC
- NDL
- Crossref
- CiNii Articles
- KAKEN
-
- 抄録ライセンスフラグ
- 使用不可
