Hydrogen trapping in carbon supersaturated α iron and its decohesion effect in martensitic steel

SCRIPTA MATERIALIA

卷:149

Article

Geng, W. T.^1,2  Wang, Vei^1,3  Li, Jin-Xu²  Ishikawa, Nobuyuki⁴  Kimizuka, Hajime¹  Tsuzaki, Kaneaki^5,6  Ogata, Shigenobu^1,6 

[1] Osaka Univ, Dept Mech Sci & Bioengn, Osaka 5608531, Japan

[2] Univ Sci & Technol Beijing, Beijing 100083, Peoples R China

[3] Xian Univ Technol, Dept Appl Phys, Xian 710054, Shaanxi, Peoples R China

[4] JFE Steel Corp, Steel Res Lab, Tokyo, Kanagawa 2100855, Japan

[5] Kyushu Univ, Dept Mech Engn, Fukuoka 8190395, Japan

[6] Kyoto Univ, Ctr Elements Strategy Initiat Struct Mat, Kyoto 6068501, Japan

关键词: Hydrogen embrittlement;    Dual-phase steel;    Martensite;    Ferrite;    Ab initio calculations;   

DOI  :  10.1016/j.scriptamat.2018.02.025

来源: Elsevier

【 摘 要 】

Our first-principles calculations demonstrate that hydrogen is more stable in carbon supersaturated martensite than in a iron, due to the carbon-induced tetragonality in martensite lattice. The trapped hydrogen leads to remarkable decohesion between (110) planes both inside the martensite and along the martensite/ferrite interface, with the former being more significant than the latter. This decohesion can explain recent precise observations that in martensite/ferrite dual-phase steels the hydrogen-promoted crack was initiated in the martensite region and that in lath martensite steel it propagated not on lath boundaries but showed quasi-cleavage feature along (110) planes at very high hydrogen concentration. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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