The mechanistic implications of the high temperature, long time thermal stability of nanoscale Mn-Ni-Si precipitates in irradiated reactor pressure vessel steels

SCRIPTA MATERIALIA

卷:181

Article

Almirall, N.^1,2  Wells, P. B.^1,2,5  Pal, S.^1,2  Edmondson, P. D.³  Yamamoto, T.^1,2  Murakami, K.⁴  Odette, G. R.^1,2 

[1] Univ Calif Santa Barbara, Dept Mech Engn, 2355 Engn 2, Santa Barbara, CA 93106 USA

[2] Univ Calif Santa Barbara, Dept Mat, 2355 Engn 2, Santa Barbara, CA 93106 USA

[3] Oak Ridge Natl Lab, Mat Sci & Technol Div, POB 2009, Oak Ridge, TN 37831 USA

[4] Univ Tokyo, Nucl Profess Sch, Tokai, Ibaraki 318119, Japan

[5] Intel Corp, Hillsboro, OR 97124 USA

关键词: Radiation damage;    Atom probe tomography;    Precipitation;    Irradiation embrittlement;    Reactor pressure vessel steels;   

DOI  :  10.1016/j.scriptamat.2020.02.027

来源: Elsevier

【 摘 要 】

Post irradiation annealing (PIA) clarified the induced versus enhanced controversy regarding nanoscale Mn-Ni-Si precipitate (MNSP) formation in pressure vessel steels. Radiation induced MNSPs would dissolve under high temperature PIA, while radiation enhanced precipitates would be stable above a critical radius (r(c)). A Cu-free, high Ni steel was irradiated with 2.8MeV Fe2+ ions at two temperatures to generate MNSPs with average radii (<(r))over bar> above and below an estimated r(c) for PIA at 425 degrees C up to 52 weeks. Atom probe tomography and energy dispersive x-ray spectroscopy showed MNSPs with r < r(c) dissolved, while those with r > r(c) slightly coarsened, consistent with thermodynamic predictions. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

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