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Interstitial hydrogen diffusion in M7C3 (M = Cr, Mn, Fe),

Krause, Andreas ; Olsson, Pär LU ; Music, Denis and Bjerkén, Christina (2023) In Computational Materials Science 218.
Abstract
To increase the understanding of the role of carbide precipitates on the hydrogen embrittlement of martensiticsteels, we have performed a density functional theory study on the solution energies and energy barriers forhydrogen diffusion in orthorhombic M7C3 (M = Cr, Mn, Fe). Hydrogen can easily diffuse into the lattice andcause internal stresses or bond weakening, which may promote reduced ductility. Solution energies of hydrogenat different lattice positions have systematically been explored, and the lowest values are -0.28, 0.00, and 0.03eV/H-atom for Cr7C3, Mn7C3, and Fe7C3, respectively. Energy barriers for the diffusion of hydrogen atoms havebeen... (More)
To increase the understanding of the role of carbide precipitates on the hydrogen embrittlement of martensiticsteels, we have performed a density functional theory study on the solution energies and energy barriers forhydrogen diffusion in orthorhombic M7C3 (M = Cr, Mn, Fe). Hydrogen can easily diffuse into the lattice andcause internal stresses or bond weakening, which may promote reduced ductility. Solution energies of hydrogenat different lattice positions have systematically been explored, and the lowest values are -0.28, 0.00, and 0.03eV/H-atom for Cr7C3, Mn7C3, and Fe7C3, respectively. Energy barriers for the diffusion of hydrogen atoms havebeen probed with the nudged elastic band method, which shows comparably low barriers for transport viainterstitial octahedral sites for all three systems. Analysis of the atomic volume reveals a correlation betweenlow solution energies and energy barriers and atoms with large atomic volumes. Furthermore, it shows that thepresence of carbon tends to increase the energy barrier. Our results can explain previous experimental findingsof hydrogen located in the bulk of Cr7C3 precipitates and provide a solid basis for future design efforts of steelswith high strength and commensurable ductility (Less)
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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Computational Materials Science
volume
218
article number
111940
publisher
Elsevier
external identifiers
  • scopus:85144276997
ISSN
0927-0256
DOI
10.1016/j.commatsci.2022.111940
language
English
LU publication?
yes
id
7b3b2187-9434-4489-83df-1f636715c10e
date added to LUP
2022-12-20 19:34:02
date last changed
2023-01-18 04:05:15
@article{7b3b2187-9434-4489-83df-1f636715c10e,
  abstract     = {{To increase the understanding of the role of carbide precipitates on the hydrogen embrittlement of martensiticsteels, we have performed a density functional theory study on the solution energies and energy barriers forhydrogen diffusion in orthorhombic M<sub>7</sub>C<sub>3</sub> (M = Cr, Mn, Fe). Hydrogen can easily diffuse into the lattice andcause internal stresses or bond weakening, which may promote reduced ductility. Solution energies of hydrogenat different lattice positions have systematically been explored, and the lowest values are -0.28, 0.00, and 0.03eV/H-atom for Cr<sub>7</sub>C<sub>3</sub>, Mn<sub>7</sub>C<sub>3</sub>, and Fe<sub>7</sub>C<sub>3</sub>, respectively. Energy barriers for the diffusion of hydrogen atoms havebeen probed with the nudged elastic band method, which shows comparably low barriers for transport viainterstitial octahedral sites for all three systems. Analysis of the atomic volume reveals a correlation betweenlow solution energies and energy barriers and atoms with large atomic volumes. Furthermore, it shows that thepresence of carbon tends to increase the energy barrier. Our results can explain previous experimental findingsof hydrogen located in the bulk of Cr<sub>7</sub>C<sub>3</sub> precipitates and provide a solid basis for future design efforts of steelswith high strength and commensurable ductility}},
  author       = {{Krause, Andreas and Olsson, Pär and Music, Denis and Bjerkén, Christina}},
  issn         = {{0927-0256}},
  language     = {{eng}},
  month        = {{02}},
  publisher    = {{Elsevier}},
  series       = {{Computational Materials Science}},
  title        = {{Interstitial hydrogen diffusion in M<sub>7</sub>C<sub>3</sub> (M = Cr, Mn, Fe),}},
  url          = {{https://lup.lub.lu.se/search/files/131964551/Krause_2023.pdf}},
  doi          = {{10.1016/j.commatsci.2022.111940}},
  volume       = {{218}},
  year         = {{2023}},
}