×

Recommended by

Indexed by

First principles study of the effect of hydrogen in austenitic stainless steels and high entropy alloys

Xiao Zhou1*, W.A. Curtin1

1 Laboratory for Multiscale Mechanics Modeling (LAMMM) and National Centre for Computational Design and Discovery of Novel Materials (NCCR MARVEL), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland

* Corresponding authors emails: x.zhou@epfl.ch
DOI10.24435/materialscloud:sw-20 [version v1]

Publication date: Oct 28, 2021

How to cite this record

Xiao Zhou, W.A. Curtin, First principles study of the effect of hydrogen in austenitic stainless steels and high entropy alloys, Materials Cloud Archive 2021.172 (2021), doi: 10.24435/materialscloud:sw-20.

Description

Hydrogen (H) embrittlement in multicomponent austenitic alloys is a serious limitation to their application in many environments. Recent experiments show that the High-Entropy Alloy (HEA) CoCrFeMnNi absorbs more H than 304 Stainless Steel but is less prone to embrittlement while the HEA CoCrFeNi is not embrittled under comparable conditions. As a first step toward understanding H embrittlement, here a comprehensive first-principles study of H absorption, surface, and fracture energies in the presence of H is presented for 304 Stainless Steel, 316 Stainless Steel, CoCrFeNi, and CoCrFeMnNi. A collinear paramagnetic model of the magnetic state is used, which is likely more realistic than previous proposed magnetic states. All alloys have a statistical distribution of H absorption sites. Hence, at low concentrations, H is effectively trapped in the lattice making it more difficult for H to segregate to defects or interfaces. Agreement with experimental H solubilities across a range of chemical potentials can be achieved with minor fitting of the average H absorption energy. The (111) surface energies for 0, 50, and 100% H surface coverage are very similar across all alloys. The fracture energies for two representative thermodynamic conditions are then determined. SS304 and CoCrFeNi are found to have the lowest fracture energies, but experiments suggest rather different embrittlement tendencies. These results indicate that differences in H embrittlement across these austenitic alloys are not due solely to differences in H absorption or H-reduced fracture energy, thus requiring more sophisticated concepts than those recently found successful for fcc Ni.

Materials Cloud sections using this data

No Explore or Discover sections associated with this archive record.

Files

File name Size Description
README.txt
MD5md5:cadb886242c0849257fcac24cfbc0732
524 Bytes readme file
Acta_HE_HEAs.zip
MD5md5:a69eb13c6b01a01c9195f939b14652f4
81.0 MiB all VASP input scripts in this paper.

License

Files and data are licensed under the terms of the following license: Creative Commons Attribution 4.0 International.
Metadata, except for email addresses, are licensed under the Creative Commons Attribution Share-Alike 4.0 International license.

Keywords

Hydrogen embrittlement complex alloys H absorption surface energy SNSF

Version history:

2021.172 (version v1) [This version] Oct 28, 2021 DOI10.24435/materialscloud:sw-20