Irradiation response of delta ferrite in as-cast and thermally aged cast stainless steel

JOURNAL OF NUCLEAR MATERIALS

卷:466

Article

Li, Zhangbo¹  Lo, Wei-Yang¹  Chen, Yiren²  Pakarinen, Janne³  Wu, Yaqiao^4,5  Allen, Todd^6,7  Yang, Yong¹ 

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

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

[3] Belgian Nucl Res Ctr SCK CEN, B-2400 Mol, Belgium

[4] Boise State Univ, Dept Mat Sci & Engn, Boise, ID 83715 USA

[5] Ctr Adv Energy Studies, Idaho Falls, ID 83401 USA

[6] Univ Wisconsin, Dept Engn Phys, Madison, WI 53706 USA

[7] Idaho Natl Lab, Idaho Falls, ID 83415 USA

关键词: Thermal aging;    Duplex stainless steel;    Neutron irradiation;    Atom probe tomography;    Delta ferrite;   

DOI  :  10.1016/j.jnucmat.2015.08.006

来源: Elsevier

【 摘 要 】

To enable the life extension of Light Water Reactors (LWRs) beyond 60 years, it is critical to gain adequate knowledge for making conclusive predictions to assure the integrity of duplex stainless steel reactor components, e.g. primary pressure boundary and reactor vessel internal. Microstructural changes in the ferrite of thermally aged, neutron irradiated only, and neutron irradiated after being thermally aged cast austenitic stainless steels (CASS) were investigated using atom probe tomography. The thermal aging was performed at 400 degrees C for 10,000 h and the irradiation was conducted in the Halden reactor at 315 degrees C to 0.08 dpa (5.6 x 10(19) n/cm(2), E > 1 MeV). Low dose neutron irradiation at a dose rate of 5 x 10(-9) dpa/s was found to induce spinodal decomposition in the ferrite of as-cast microstructure, and further to enhance the spinodal decomposition in the thermally aged cast alloys. Regarding the G-phase precipitates, the neutron irradiation dramatically increases the precipitate size, and alters the composition of the precipitates with increased, Mn, Ni, Si and Mo and reduced Fe and Cr contents. The results have shown that low dose neutron irradiation can further accelerate the degradation of ferrite in a duplex stainless steel at the LWR relevant condition. Published by Elsevier B.V.

【 授权许可】

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