Ab initiomodelling of the interaction of H interstitials with grain boundaries in bcc Fe

Hydrogen Trapping in bcc Iron

“…Vacancies belong to one of the most common thermal defect types considered in the literature in relation to the problem of HE. They play an important role in diffusion processes in Fe [33,72,73] and in trapping of H atoms [1,13]. The formation energy of a vacancy in FM Fe at 0 K is shown in Table 2.…”

“…A significant amount of effort has been made with respect to investigations of H-trapping in Fe [9][10][11][12][13][14][15][16][17][18][19][20][21]. Most research works have focused on the identification of the most favorable position of the atomic H in the lattice or at a defect with the lowest trapping energy at 0 K. The data available in the literature suggest that the strongest traps for H at 0 K should be some special grain boundaries (GBs) [13,22].…”

“…A significant amount of effort has been made with respect to investigations of H-trapping in Fe [9][10][11][12][13][14][15][16][17][18][19][20][21]. Most research works have focused on the identification of the most favorable position of the atomic H in the lattice or at a defect with the lowest trapping energy at 0 K. The data available in the literature suggest that the strongest traps for H at 0 K should be some special grain boundaries (GBs) [13,22]. Hydrogen trapping at special coincident site lattice (CSL) GBs has been described so far for the tilt Σ3 (111), Σ5(012), Σ5(013) [13], Σ9(1/2 11), Σ13(1/3 11), Σ17(1/4 11) [15], and twist Σ3 (110), Σ9 (110), Σ11 (110), Σ17 (110) [14] GBs.…”

“…Most research works have focused on the identification of the most favorable position of the atomic H in the lattice or at a defect with the lowest trapping energy at 0 K. The data available in the literature suggest that the strongest traps for H at 0 K should be some special grain boundaries (GBs) [13,22]. Hydrogen trapping at special coincident site lattice (CSL) GBs has been described so far for the tilt Σ3 (111), Σ5(012), Σ5(013) [13], Σ9(1/2 11), Σ13(1/3 11), Σ17(1/4 11) [15], and twist Σ3 (110), Σ9 (110), Σ11 (110), Σ17 (110) [14] GBs. Trapping energies as strong as −0.81 eV, −0.83 eV and −0.95 eV have been found for the Σ5(012) [100] tilt GB [13], and the Σ11 (110) and Σ17 (110) twist GBs [14], respectively.…”

“…Hydrogen trapping at special coincident site lattice (CSL) GBs has been described so far for the tilt Σ3 (111), Σ5(012), Σ5(013) [13], Σ9(1/2 11), Σ13(1/3 11), Σ17(1/4 11) [15], and twist Σ3 (110), Σ9 (110), Σ11 (110), Σ17 (110) [14] GBs. Trapping energies as strong as −0.81 eV, −0.83 eV and −0.95 eV have been found for the Σ5(012) [100] tilt GB [13], and the Σ11 (110) and Σ17 (110) twist GBs [14], respectively. DFT studies on H-trapping at the edge and screw dislocations [16,17,23] suggest a range of the trapping energies from −0.19 to −0.47 [16,17,23]; i.e., sizeably lower values than those of the special GBs.…”