Instability of MX and M23C6 type precipitates in F82H steels under 2.8 MeV Fe2+ irradiation at 673 K

Sho Kano; Huilong Yang; Jingjie Shen; Zishou Zhao; John McGrady; Dai Hamaguchi; Mamami Ando; Hiroyasu Tanigawa; Hiroaki Abe

Nuclear Materials and Energy (Dec 2018)

Instability of MX and M23C6 type precipitates in F82H steels under 2.8 MeV Fe2+ irradiation at 673 K

Sho Kano,
Huilong Yang,
Jingjie Shen,
Zishou Zhao,
John McGrady,
Dai Hamaguchi,
Mamami Ando,
Hiroyasu Tanigawa,
Hiroaki Abe

Affiliations

Sho Kano: Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata-shirane, Naka, Tokai, Ibaraki 319-1188, Japan; Corresponding author.
Huilong Yang: Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata-shirane, Naka, Tokai, Ibaraki 319-1188, Japan
Jingjie Shen: Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata-shirane, Naka, Tokai, Ibaraki 319-1188, Japan
Zishou Zhao: Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata-shirane, Naka, Tokai, Ibaraki 319-1188, Japan
John McGrady: Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata-shirane, Naka, Tokai, Ibaraki 319-1188, Japan
Dai Hamaguchi: Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata-shirane, Naka, Tokai, Ibaraki 319-1188, Japan
Mamami Ando: National Institutes for Quantum and Radiological Science and Technology(QST), Fusion Research and Development Directorate, Division of Rokassho BA Project, Structural Materials Development Group, 2-166 Omotedate, Obuchi, Rokkasho, Aomori 039-3212, Japan
Hiroyasu Tanigawa: National Institutes for Quantum and Radiological Science and Technology(QST), Fusion Research and Development Directorate, Division of Rokassho BA Project, Structural Materials Development Group, 2-166 Omotedate, Obuchi, Rokkasho, Aomori 039-3212, Japan
Hiroaki Abe: Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata-shirane, Naka, Tokai, Ibaraki 319-1188, Japan

Journal volume & issue: Vol. 17
pp. 56 – 61

Abstract

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The purpose of this study is to investigate the response of the precipitates against irradiation in F82H steels which are considered as main candidate structure material for the fusion DEMO reactor blanket. M23C6-type precipitates contained F82H-IEA steel, and MX- and M23C6-type precipitates contained F82H-BA12 steel were selected as experimental specimens. Iron irradiation at 673 K using ion accelerator was performed on both steels up to 50 dpa. After irradiation, the instability behavior of precipitates was characterized using transmission electron microscopy. It is found that in F82H-IEA specimens, the number density of radiation defects at 20 dpa was 3.26 × 1021 m−3, and the amorphization of M23C6 was undetected up to 50 dpa. Although Ostwald ripening occurred in M23C6 precipitates, the average size of M23C6 mildly decreased with irradiation dose within this study. For F82H-BA12 specimens, the shrinkage rate of MX- and M23C6-type precipitates was estimated respectively as 0.06 and 0.03 nm/dpa. Hence, the MX and M23C6-type precipitates in F82H steel exhibit an excellent irradiation resistance under the present irradiation condition. Moreover, the behaviors like amorphization and weakening in contrast were not observed in M23C6 precipitates in both specimens, which is different from electron irradiation, presumably due to the factors such as different damage rate. Keywords: F82H, Ion irradiation, Precipitates, Instability

Published in Nuclear Materials and Energy

ISSN: 2352-1791 (Online)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering: Nuclear engineering. Atomic power
Website: http://www.journals.elsevier.com/nuclear-materials-and-energy/

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