Hydrogen effect on thermodynamic stability of γ- and ε-phases in a Fe–Cr–Mn solid solution

Hydrogen effect on thermodynamic stability of γ- and ε-phases in a Fe–Cr–Mn solid solution

Ab initio calculations of the cohesion energy in the fcc γ- and hcp ε-phases of the hydrogen-free and hydrogen-charged Fe50Cr25Mn25 solid solutions are carried out in order to estimate the hydrogen effect on the γ → ε transformation. It is obtained that, at hydrogen contents within the range of 20–3...

Full description

Saved in:
Bibliographic Details
Published in:International journal of hydrogen energy Vol. 38; no. 20; pp. 8471 - 8477
Main Authors: Movchan, D.N., Shanina, B.D., Gavriljuk, V.G.
Format: Journal Article
Language:English
Published: Kidlington Elsevier Ltd 09-07-2013
Elsevier
Subjects:
Ab initio calculations
Alternative fuels. Production and utilization
Applied sciences
Energy
Exact sciences and technology
Fuels
Hydrogen
Iron-based alloys
Phase transformations
Iron-based alloys
Ab initio calculations
Phase transformations
Hydrogen
Phase transformation
Thermodynamic stability
Iron alloy
Solid solution
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Ab initio calculations of the cohesion energy in the fcc γ- and hcp ε-phases of the hydrogen-free and hydrogen-charged Fe50Cr25Mn25 solid solutions are carried out in order to estimate the hydrogen effect on the γ → ε transformation. It is obtained that, at hydrogen contents within the range of 20–35 at.%, the fcc and hcp structures reveal a comparable thermodynamic stability with some preference for the hcp one. With further increase in the hydrogen content, the fcc phase is again stabilized. The comparison with similar calculations for the Fe50Cr25Ni25 solid solutions shows that, in contrast to expectations, the substitution of nickel for manganese in the austenitic steels retards the hydrogen-induced γ → ε transformation. The obtained results are also compared with available experimental data and discussed in terms of stacking fault energy changed under combined hydrogen, nickel and manganese effects. •Hydrogen-induced γ → ε transformation in CrMn austenitic steel is studied by ab initio calculations.•Hydrogen slightly decreases stability of austenite at 20–40 at.% H.•The hydrogen effect in CrMn austenitic steels is weaker than in CrNi ones.•Non-additive effects of H, Cr, Ni and Mn on the SFE in fcc iron is suggested.
ISSN:0360-3199
1879-3487
DOI:10.1016/j.ijhydene.2013.04.145