A multi-scale analysis of the different interactions between defects and hydrogen: A review on the contribution of the elastic fields

Hachet, Guillaume; Li, J.; Hallil, A.; Metsue, Arnaud; Oudriss, A.; Bouhattate, J.; Feaugas, X.

doi:10.1016/j.engfracmech.2019.106621

“…More recently, the contribution of defects and elastic anisotropy have been questioned on the solubility and diffusivity in nickel 16 . The contribution of shear elastic energy far from any defect stays less common feature related in the literature but a few works show clearly the significance of that one 69 – 71 , 73 , 88 . The shear or deviatoric elastic strain energy can be mostly near the dislocation core and have a large contribution to the trapping energy 70 , 71 .…”

Section: Discussionmentioning

confidence: 99%

Antagonist effects of grain boundaries between the trapping process and the fast diffusion path in nickel bicrystals

Li

¹

,

Hallil

²

,

Metsue

³

et al. 2021

Sci Rep

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Hydrogen-grain-boundaries interactions and their role in intergranular fracture are well accepted as one of the key features in understanding hydrogen embrittlement in a large variety of common engineer situations. These interactions implicate some fundamental processes classified as segregation, trapping and diffusion of the solute which can be studied as a function of grain boundary configuration. In the present study, we carried out an extensive analysis of four grain-boundaries based on the complementary of atomistic calculations and experimental data. We demonstrate that elastic deformation has an important contribution on the segregation energy which cannot be simply reduced to a volume change and need to consider the deviatoric part of strain. Additionally, some significant configurations of the segregation energy depend on the long-range elastic distortion and allows to rationalize the elastic contribution in three terms. By investigating the different energy barriers involved to reach all the segregation sites, the antagonist impact of grain boundaries on hydrogen diffusion and trapping process was elucidated. The segregation energy and migration energy are two fundamental parameters in order to classify the grain-boundaries as a trapping location or short circuit for diffusion.

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“…More recently, the contribution of defects and elastic anisotropy have been questioned on the solubility and diffusivity in nickel 16 . The contribution of shear elastic energy far from any defect stays less common feature related in the literature but a few works show clearly the significance of that one [69][70][71]73,87 . The shear or deviatoric elastic strain energy #1 4 can be mostly near the dislocation core and have a large contribution to the trapping energy 70,71 .…”

Section: Discussionmentioning

confidence: 99%

“…The degradation of elastic properties correlated to the incorporation of hydrogen is known well documented in the literature 17,73,[76][77][78][79][80][81] .…”

Section: Segregation Energy Versus Elastic Energymentioning

confidence: 91%

“…The contribution of the elastic strain energy of this process can be evaluated by considering the respective effect of hydrostatic strain (change of the volume) and shear strain (change of the morphology, deviatoric part of strain). In order to investigate the contribution of the elastic strain energy to the segregation process the elastic dipole tensor Pij is used to describe the equilibrium in a continuum solid of a point-force distribution 47,[73][74][75] . The elastic dipole tensor characterizes the changes for both the volume and the shape of the interstitial site during the relaxation procedure after the incorporation of the solute in the lattice.…”

Section: Segregation Energy Versus Elastic Energymentioning

confidence: 99%

“…As previously highlighted in different configurations, the insertion of a solute in a specific location induces a geometric transformation which cannot be only described as a volume change (see as examples 16,47,[68][69][70][71][72][73] ). The modification of the geometric configuration of the volume defined by Voronoi's method results in an equilibrium with the different interactions between the neighboring atoms of the solute.…”

Section: Segregation Energy Versus Elastic Energymentioning

confidence: 99%

See 2 more Smart Citations

Some Advances on Antagonist Effects of Grain Boundaries between the Trapping Process and the Fast Diffusion Path Investigated on Nickel Bicrystals

Feaugas¹,

Li²,

Hallil³

et al. 2021

Preprint

0

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Hydrogen-grain-boundaries interactions and their role in intergranular fracture are well accepted as one of the key features in understanding hydrogen embrittlement in a large variety of common engineer situations. These interactions implicate some fundamental processes classified as segregation, trapping and diffusion of the solute which can be studied as a function of grain boundary configuration. In the present study, we carried out an extensive analysis of four grain-boundaries based on the complementary of atomistic calculations and experimental data. We demonstrate that elastic deformation has an important contribution on the segregation energy which cannot be simply reduced to a volume change and need to consider the deviatoric part of strain. Additionally, some significant configurations of the segregation energy depend on the long-range elastic distortion and allows to rationalize the elastic contribution in three terms. By investigating the different energy barriers involved to reach all the segregation sites, the antagonist impact of grain boundaries on hydrogen diffusion and trapping process was elucidated. The segregation energy and migration energy are two fundamental parameters in order to classify the grain-boundaries as a trapping location or short circuit for diffusion.

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Preliminary Evaluation of the Influence of Hydrogen on the Fracture Toughness of an X65 Gas‐Transmission Pipeline Steel

Chowdhury,

Tapia‐Bastidas,

Hoschke

et al. 2024

Adv Eng Mater

0

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Previous research has indicated that hydrogen decreases the fracture toughness of gas transmission pipeline steels. This study produced two values of fracture toughness for the X65 steel in the Dampier Bunbury Natural Gas pipeline in air (JQ of 590 and 778 kJ/m2; equivalent to KQ of 369 MPa and 487 MPa) and two essentially ASTM‐valid values of fracture toughness of KJ1C of 150 MPa and 189 MPa for X65 subjected to in‐situ hydrogen charging thought to be equivalent to a hydrogen gas pressure of 200 bar. The fracture toughness for hydrogen‐charged specimens was lower than in air. The large spread of the fracture toughness in air was attributable to the fact that these JQ values were dependent on testing details. The spread of fracture toughness values in hydrogen was attributed to the variability of fracture toughness in hydrogen under these hydrogen charging conditions. There was considerable stable crack growth. The energy for stable crack growth increased with crack length. The fractography in the presence of hydrogen showed significant ductility, consistent with hydrogen assisted plastic fracture. The values of fracture toughness in air and with hydrogen were consistent with literature values.This article is protected by copyright. All rights reserved.

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A multi-scale analysis of the different interactions between defects and hydrogen: A review on the contribution of the elastic fields

Cited by 20 publications

References 44 publications

Antagonist effects of grain boundaries between the trapping process and the fast diffusion path in nickel bicrystals

Antagonist effects of grain boundaries between the trapping process and the fast diffusion path in nickel bicrystals

Some Advances on Antagonist Effects of Grain Boundaries between the Trapping Process and the Fast Diffusion Path Investigated on Nickel Bicrystals

Preliminary Evaluation of the Influence of Hydrogen on the Fracture Toughness of an X65 Gas‐Transmission Pipeline Steel

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