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

Journal Article · Sat Aug 08 00:00:00 EDT 2015 · Journal of Nuclear Materials

DOI:https://doi.org/10.1016/j.jnucmat.2015.08.006· OSTI ID:1273150

Li, Zhangbo ^[1]; Lo, Wei-Yang ^[1]; Chen, Yiren ^[2]; Pakarinen, Janne ^[3]; Wu, Yaqiao ^[4]; Allen, Todd ^[5]; Yang, Yong ^[1]

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1. Univ. of Florida, Gainesville, FL (United States). Dept. of Materials Science and Engineering
2. Argonne National Lab. (ANL), Lemont, IL (United States). Nuclear Engineering Div.
3. Belgian Nuclear Research Center (SCK-CEN), Mol (Belgium)
4. Boise State Univ., ID (United States). Dept of Materials Science and Engineering; Center for Advanced Studies, Idaho Falls, ID (United States)
5. Univ. of Wisconsin, Madison, WI (United States). Engineering Physics Dept.; Idaho National Lab. (INL), Idaho Falls, ID (United States)

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 °C for 10,000 h and the irradiation was conducted in the Halden reactor at ~315 °C to 0.08 dpa (5.6 × 10¹⁹ n/cm² E > 1 MeV). Low dose neutron irradiation at a dose rate of 5 × 10^-9 dpa/s was found to induce spinod,al 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. Lastly, 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.

• Research Organization: Idaho National Laboratory (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• Grant/Contract Number: AC07-051D14517
• OSTI ID: 1273150
• Alternate ID(s): OSTI ID: 1252253
• Journal Information: Journal of Nuclear Materials, Vol. 466, Issue C; ISSN 0022-3115
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
thermal aging
duplex stainless steel
neutron irradiation
atom probe tomography
delta ferrite