Hydrogen bubble nucleation in α-iron. (June 2017)

• Record Type: Journal Article
• Authors: Geng, W.T.; Wan, Liang; Du, Jun-Ping; Ishii, Akio; Ishikawa, Nobuyuki; Kimizuka, Hajime; Ogata, Shigenobu
• Is Part Of: Scripta materialia. Number 134(2017)
• Page Start: 105
• Page End: 109
• Publication Date: 2017-06
• Subjects: Steel -- Ab initio calculations -- Hydrogen induced cracking -- Blistering; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2017.03.006
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: We report a first-principles study on how H2 molecules emerge in a nanovoid in α-iron. In a 9-vacancy void, after the walls are decorated with 24 H atoms, only H-dimers are allowed to be adsorbed on the walls; whereas in a spherical 27-vacancy void, H2 molecules start to appear in the center of the void after the walls are saturated by 54 H atoms. The bubble pressure can reach 3.5 GPa, comparable to the measured H2 pressure in blisters at the micrometer scale. The H-saturated nanovoid attracts vacancy more strongly than does the pristine nanovoid through strong H-vacancy interaction. Graphical abstract: