Atomistic simulation study of the grain-size effect on hydrogen embrittlement of nanograined Fe

Xiao Ye Zhou, Xu Sheng Yang, Ji Hua Zhu, Feng Xing

Research output: Journal article publicationJournal articleAcademic researchpeer-review

7 Citations (Scopus)

Abstract

Although hydrogen-induced fracture at grain boundaries has been widely studied and several mechanisms have been proposed, few studies of nanograined materials have been conducted, especially for grain sizes below the critical size for the inverse Hall-Petch relation. In this research work, molecular dynamics (MD) simulations are performed to investigate the hydrogen segregation and hydrogen embrittlement mechanism in polycrystalline Fe models. When the same concentration of H atoms is added, the H segregation ratio in the model with the smallest grain size is the highest observed herein, showing the high hydrogen trapping ability of small-grain Fe, while the H concentration at the grain boundaries (GBs) is, on the contrary, the lowest. Uniaxial tensile test simulations demonstrate that as the grain size decreases, the models show an increased resistance to hydrogen embrittlement, and for small-grain models (d < 10 nm), the GB-related deformation modes dominate the plastic deformation, where the segregated H mainly influences the toughness by inhibiting GB-related processes.

Original languageEnglish
Pages (from-to)3294-3306
Number of pages13
JournalInternational Journal of Hydrogen Energy
Volume45
Issue number4
DOIs
Publication statusPublished - 24 Jan 2020

Keywords

  • Fracture mechanisms
  • Grain boundaries
  • Hydrogen embrittlement
  • Molecular dynamics simulation

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Condensed Matter Physics
  • Energy Engineering and Power Technology

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