TY - JOUR
T1 - In situ study of heavy ion induced radiation damage in NF616 (P92) alloy
AU - Topbasi, Cem
AU - Motta, Arthur T.
AU - Kirk, Mark A.
N1 - Funding Information:
This work was funded by the Nuclear Energy Research Initiative Consortium (NERI-C) Award number DE-FG07-07ID14894 from the US Department of Energy. The research conducted in the IVEM-Accelerator facility at Argonne National Laboratory, which is supported as a User Facility by the US Department of Energy, Basic Energy Sciences, under contract W-31-109-ENG-38. We thank Pete Baldo of Argonne National Lab for his help in performing the irradiations. We also thank Djamel Kaoumi, Brian Wirth and Aaron Kohnert for helpful discussions.
PY - 2012/6
Y1 - 2012/6
N2 - NF616 is a nominal 9Cr ferritic-martensitic steel that is amongst the primary candidates for cladding and duct applications in the Sodium-Cooled Fast Reactor, one of the Generation IV nuclear energy systems. In this study, an in situ investigation of the microstructure evolution in NF616 under heavy ion irradiation has been conducted. NF616 was irradiated to 8.4 dpa at 50 K and to 7.6 dpa at 473 K with 1 MeV Kr ions. Nano-sized defects first appeared as white dots in dark-field TEM images and their areal density increased until saturation (∼6 dpa). Dynamic observations at 50 K and 473 K showed appearance and disappearance of TEM-visible defect clusters under irradiation that continued above saturation dose. Quantitative analysis showed no significant change in the average size (∼3-4 nm) and distribution of defect clusters with increasing dose at 50 K and 473 K. These results indicate a cascade-driven process of microstructure evolution under irradiation in these alloys that involves both the formation of TEM-visible defect clusters by various degrees of cascade overlap and cascade induced defect cluster elimination. According to this mechanism, saturation of defect cluster density is reached when the rate of defect cluster formation by overlap is equal to the rate of cluster elimination during irradiation.
AB - NF616 is a nominal 9Cr ferritic-martensitic steel that is amongst the primary candidates for cladding and duct applications in the Sodium-Cooled Fast Reactor, one of the Generation IV nuclear energy systems. In this study, an in situ investigation of the microstructure evolution in NF616 under heavy ion irradiation has been conducted. NF616 was irradiated to 8.4 dpa at 50 K and to 7.6 dpa at 473 K with 1 MeV Kr ions. Nano-sized defects first appeared as white dots in dark-field TEM images and their areal density increased until saturation (∼6 dpa). Dynamic observations at 50 K and 473 K showed appearance and disappearance of TEM-visible defect clusters under irradiation that continued above saturation dose. Quantitative analysis showed no significant change in the average size (∼3-4 nm) and distribution of defect clusters with increasing dose at 50 K and 473 K. These results indicate a cascade-driven process of microstructure evolution under irradiation in these alloys that involves both the formation of TEM-visible defect clusters by various degrees of cascade overlap and cascade induced defect cluster elimination. According to this mechanism, saturation of defect cluster density is reached when the rate of defect cluster formation by overlap is equal to the rate of cluster elimination during irradiation.
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U2 - 10.1016/j.jnucmat.2011.08.046
DO - 10.1016/j.jnucmat.2011.08.046
M3 - Article
AN - SCOPUS:84860479496
VL - 425
SP - 48
EP - 53
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
SN - 0022-3115
IS - 1-3
ER -