On the formation and structure of Mn-Ni-Si Γ2 precipitates in steels
File(s)
Accepted version
Author(s)
Whiting, TM
King, DJM
Wenman, MR
Type
Journal Article
Abstract
The Γ2-phase is postulated to form from solute clusters in neutron irradiated low-alloy steels. Density functional theory calculations were used to identify the ground state Γ2 structures with variation in Si and Ni contents. It was found that favourability of the Γ2-phase was proportional to Si content, however Si-Si first nearest neighbours reduced favourability. The substitutional enthalpies of Al, Cr, Cu, Fe, Ge, Hf, Mo, Nb, P, Ta, Ti, V, Zr, and vacancies into the ground state Γ2-phase structure from a ferrite matrix were calculated. It was found that Zr, Hf, Nb, Cu, Ti and Ta favourably substitute onto the Mn sites, Cu and P onto the Si sites and Cu onto the Ni sites and vacancies will substitute favourably onto all atomic sites. Finally, it is shown that, for ≤20 at% Fe concentrations, the Γ2-phase becomes more favourable than the bcc structure therefore it is plausible that the Γ2-phase could be thermodynamically stabilised provided these conditions are met.
Date Issued
2020-12
Date Acceptance
2020-07-31
Citation
Journal of Nuclear Materials, 2020, 542, pp.1-7
ISSN
0022-3115
Publisher
Elsevier BV
Start Page
1
End Page
7
Journal / Book Title
Journal of Nuclear Materials
Volume
542
Copyright Statement
© 2020 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
Rolls-Royce Plc
Engineering and Physical Sciences Research Council
Identifier
https://www.sciencedirect.com/science/article/pii/S0022311520310370?via%3Dihub
Grant Number
5003023643
EP/P005101/1
Subjects
0912 Materials Engineering
Energy
Publication Status
Published online
Article Number
152429
Date Publish Online
2020-08-07