Ab initiostudy of the solubility and kinetics of hydrogen in austenitic high Mn steels

Solution enthalpy of hydrogen in fourth row elements: Systematic trends derived from first principles

“…In order to discriminate between direct and indirect effects, the lattice constants of the elements have to be taken into account. Previous studies 11 as well as our own investigations 13 have already indicated that apart from the chemical structure of the host lattice, the distance of the interstitial to its next neighboring metallic atom is a decisive parameter controlling H solubility. For example, H solubility increases when alloying Fe with Mn or C, which both expand the Fe lattice.…”

“…Recent ab initio studies on H in Fe and Mn showed a strong influence of the metal lattice constant on the solution enthalpy. 13 A detailed analysis showed that differences in the solubility between these two materials can solely be explained by changes in the host lattice constants and subsequently with changes in the interstitial volume.…”

Impact of Mn on the solution enthalpy of hydrogen in austenitic Fe‐Mn alloys: A first‐principles study

“…[19] The most instructive measure for this geometric effect is the Voronoi volume of the octahedral site. [9] Therefore, a Voronoi analysis has been performed for all the octahedral configurations present in the Fe 16 Mn 16 supercell. Afterwards the H solution enthalpies in Figure 1a are plotted not anymore as a function of the number of Mn nearest neighbors but as a function of the Voronoi volume (Fig.…”

“…[22] In the case of the H solution enthalpy in Fe-Mn alloys, however, previous investigations showed little dependence on the exact magnetic structure. [9] Electronic structures of cells optimized with VASP were calculated using the TB-Linear Muffin-Tin Orbital (LMTO)-ASA 4.7 program code [23] and applying the GGA functional of Perdew and Wang. [24] The program is based on the all-electron scalarrelativistic LMTO theory.…”

“…It is already known that the octahedral interstital sites are more preferable than tetrahedral sites for H interstitials in fcc Fe. [9] Considering binary Fe-Mn alloys, however, even the restriction to octahedral interstitial sites provides 10 different atomic configurations, if only the chemical environment of the nearest neighbors is considered (Fig. 1).…”