TY - JOUR
T1 - Electron-irradiation-induced Cr segregation in Fe-Cr model alloy pre-implanted with hydrogen ions
AU - Du, Yufeng
AU - Han, Wentuo
AU - Cui, Lijuan
AU - Wan, Farong
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China (Grand No. 51471026 ). The authors gratefully acknowledge the High Voltage Electron Microscope Laboratory in Hokkaido University, Japan. The help and suggestions from Professor Hashimoto Naoyuki were highly appreciated.
Publisher Copyright:
© 2018 Elsevier Inc.
PY - 2018/5
Y1 - 2018/5
N2 - Reduced activation ferritic/martensitic (RAFM) steels are widely accepted as the candidate structural materials for fusion reactors. To gain knowledge about Cr behaviour of these steels in such environments, Fe-Cr binary alloys have to be investigated. In this study, Fe-10 at.% Cr ferritic model alloy pre-implanted with hydrogen ions was electron-irradiated in a high voltage electron microscope (HVEM) at the temperature ranging from 300 °C to 600 °C. Streaks were observed in the diffraction patterns in the model alloy after electron irradiation at 450–550 °C and explained reasonably by shape effect. The analysis of transmission electron microscopy (TEM) reveals that the observed streaks are induced by a kind of needle-like precipitates with the directions along 〈100〉. The dependence of the length and density of the precipitates on the temperature were studied. In addition, contrast experiments were conducted with pure Fe and Fe-10 at.% Cr alloy with and without hydrogen ion implantation, respectively. After electron irradiation, no streak was observed in the hydrogen-implanted pure Fe and Fe-10 at.% Cr alloy without the hydrogen implantation. Therefore, it is assumed that the needle-like precipitates could be the complex of Cr and H, which segregate and precipitate along 〈100〉 direction.
AB - Reduced activation ferritic/martensitic (RAFM) steels are widely accepted as the candidate structural materials for fusion reactors. To gain knowledge about Cr behaviour of these steels in such environments, Fe-Cr binary alloys have to be investigated. In this study, Fe-10 at.% Cr ferritic model alloy pre-implanted with hydrogen ions was electron-irradiated in a high voltage electron microscope (HVEM) at the temperature ranging from 300 °C to 600 °C. Streaks were observed in the diffraction patterns in the model alloy after electron irradiation at 450–550 °C and explained reasonably by shape effect. The analysis of transmission electron microscopy (TEM) reveals that the observed streaks are induced by a kind of needle-like precipitates with the directions along 〈100〉. The dependence of the length and density of the precipitates on the temperature were studied. In addition, contrast experiments were conducted with pure Fe and Fe-10 at.% Cr alloy with and without hydrogen ion implantation, respectively. After electron irradiation, no streak was observed in the hydrogen-implanted pure Fe and Fe-10 at.% Cr alloy without the hydrogen implantation. Therefore, it is assumed that the needle-like precipitates could be the complex of Cr and H, which segregate and precipitate along 〈100〉 direction.
KW - Cr needle-like precipitates
KW - Electron irradiation
KW - Hydrogen effect
KW - Streak diffraction
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U2 - 10.1016/j.matchar.2018.03.019
DO - 10.1016/j.matchar.2018.03.019
M3 - Article
AN - SCOPUS:85044123089
SN - 1044-5803
VL - 139
SP - 364
EP - 372
JO - Materials Characterization
JF - Materials Characterization
ER -