Phase stability in thermally-aged CASS CF8 under heavy ion irradiation

Journal Article · Fri Mar 20 00:00:00 EDT 2015 · Journal of Nuclear Materials

DOI:https://doi.org/10.1016/j.jnucmat.2015.03.034· OSTI ID:1271883

Li, Meimei ^[1]; Miller, Michael K. ^[2]; Chen, Wei-Ying ^[1]

---

1. Argonne National Lab. (ANL), Argonne, IL (United States)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

The stability of the microstructure of a cast austenitic stainless steel (CASS), before and after heavy ion irradiation, was investigated by atom probe tomography (APT). A CF8 ferrite–austenite duplex alloy was thermally aged at 400°C for 10,000 h. After this treatment, APT revealed nanometer-sized G-phase precipitates and Fe-rich α and Cr-enriched α' phase separated regions in the ferrite. The thermally-aged CF8 specimen was irradiated with 1 MeV Kr ions to a fluence of 1.88 × 10¹⁹ ions/m² at 400°C. Post irradiation, APT analysis revealed a strong spatial/dose dependence of the G-phase precipitates and the α–α' spinodal decomposition in the ferrite. For the G-phase precipitates, the number density increased and the mean size decreased with increasing dose, and the particle size distribution changed considerably under irradiation. The inverse coarsening process can be described by recoil resolution. Lastly, the amplitude of the α–α' spinodal decomposition in the ferrite was apparently reduced after heavy ion irradiation.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1271883
• Journal Information: Journal of Nuclear Materials, Vol. 462; ISSN 0022-3115
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY