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Precipitation kinetics of radiation-induced Ni-Mn-Si phases in VVER-1000 reactor pressure vessel steels under low and high flux irradiation

Authors :
Evgenia Kuleshova
I.V. Fedotov
D.A. Maltsev
S.V. Fedotova
G.M. Zhuchkov
A.S. Frolov
Source :
Journal of Nuclear Materials. 553:153091
Publication Year :
2021
Publisher :
Elsevier BV, 2021.

Abstract

One of the key embrittlement mechanisms in reactor pressure vessel (RPV) steels is the hardening produced by nanometer features. In this paper low Cu high Ni VVER-1000 RPV steels with a wide range of Ni (1.1–1.94wt.%) and Mn (0.38–1.1wt.%) contents irradiated at 290°C to (6–101) 1022 n/m22 (E>0.5MeV) at both low (surveillance specimens) and high (test reactor) fluxes were analyzed using atom probe tomography and transmission electron microscopy. Formation of high number density of NMS precipitates with the average composition close to at.%: 45Ni-33Si-22Mn regardless of the irradiation conditions was observed. Its number density increases with the increase of the total Ni and Mn concentration in steel. High flux irradiation demonstrates lower size and volume fraction of NMS precipitates compared to the low flux irradiation in case of welds. For the base metal specimens with low Ni (1.1–1.3 wt.%) and Mn (0.38–0.51) content no flux effect was observed. The contribution of NMS phases and dislocation loops into radiation hardening of RPV steels was established by the dispersed barrier strength model (Orowan equation).

Details

ISSN :
00223115
Volume :
553
Database :
OpenAIRE
Journal :
Journal of Nuclear Materials
Accession number :
edsair.doi...........457b2aaeaa5af2804ba3c06f8bd56693
Full Text :
https://doi.org/10.1016/j.jnucmat.2021.153091