Microstructural evolution of NF709 austenitic stainless steel under in-situ ion irradiations at room temperature, 300, 400, 500 and 600 °C

JOURNAL OF NUCLEAR MATERIALS

卷:509

Article

Xu, Chi^1,2  Chen, Wei-Ying²  Chen, Yiren²  Yang, Yong¹ 

[1] Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA

[2] Argonne Natl Lab, Nucl Engn Div, Lemont, IL 60439 USA

关键词: NF709;    Austenitic stainless steel;    In-situ ion irradiation;    Irradiation microstructure;   

DOI  :  10.1016/j.jnucmat.2018.07.044

来源: Elsevier

【 摘 要 】

Irradiation induced microstructural changes in the NF709 austenitic stainless steel were investigated under 1 MeV Kr ion irradiations to a dose of 3 dpa at room temperature (RT), 300, 400, 500 and 600 degrees C, and a dose of 20 dpa at RT. The irradiation-induced defects and the stability of precipitates were characterized with transmission electron microscopy (TEM). Frank dislocation loops were observed in all the irradiated samples, and the loop sizes were much larger at 600 degrees C than those at lower temperatures. Raft defect structures, formed through self-alignment of small dislocation loops, were also observed in all irradiated samples. M23C6 precipitates were amorphorized under irradiations at RT and 300 degrees C, but remained to be crystalline at 400 degrees C and above. MX precipitates were stable under irradiations at RT up to 20 dpa, and at temperatures below 600 degrees C to 3 dpa. At 600 degrees C, some MX precipitates were observed to dissolve during in-situ irradiation, suggesting possible precipitate instability at this irradiation temperature. (C) 2018 Elsevier B.V. All rights reserved.

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