Abstract
Hydrogen embrittlement (HE) substantially deteriorates the mechanical properties of metals. The HE behavior of nanograined (NG) materials with a high fraction of grain boundaries (GBs) may significantly differ from those of their coarse-grained counterparts. Herein, molecular dynamics (MD) simulations were performed to investigate the HE behavior and mechanism of NG α-Fe under creep loading. The effects of temperature, sustained stress, and grain size on the creep mechanism was examined based on the Mukherjee-Bird-Dorn (MBD) equation. The deformation mechanisms were found to be highly dependent on temperature, applied stress, and grain size. Hydrogen charging was found to have an inhibitory effect on the GB-related deformation mechanism. As the grain size increased, the HE mechanism transitioned from H-induced inhibition of GB-related deformation to H-enhanced GB decohesion. The current results might provide theoretical guidance for designing NG structural materials with low HE sensitivity and better mechanical performance.
Original language | English |
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Pages (from-to) | 9613-9629 |
Number of pages | 17 |
Journal | International Journal of Hydrogen Energy |
Volume | 46 |
Issue number | 14 |
DOIs | |
Publication status | Published - 24 Feb 2021 |
Keywords
- Creep behavior
- Hydrogen embrittlement
- Molecular dynamics simulations
- Nanograined materials
- Plastic deformation mechanism
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Condensed Matter Physics
- Energy Engineering and Power Technology