Abstract
Ferritic/Martensitic (F/M) steels containing 9 wt.% Cr are candidates for structural and cladding components in the next generation of advanced nuclear fission and fusion reactors. Although it is known these alloys exhibit radiation-induced segregation (RIS) at grain boundaries (GBs) while in-service, little is known about the mechanism behind RIS in F/M steels. The classical understanding of RIS in F/M steels presents a mechanism where point defects migrate to GBs acting as perfect sinks. However, variation in grain boundary structure may influence the sink efficiency and these migration processes. A proton irradiated 9 wt.% Cr model alloy steel was investigated using STEM/EDS spectrum imaging and GB misorientation analysis to determine the role of GB structure on RIS at different GBs. An ab initio based rate theory model was developed and compared to the experimental findings. This investigation found Cr preferentially segregates to specific GB structures. The preferential segregation to specific GB structures suggests GB structure plays a key role in the mechanism behind radiation-induced segregation, showing that not all grain boundaries in F/M steels act as perfect sinks. The study also found how irradiation dose and temperature impact the radiation-induced segregation response in F/M steels.
| Original language | English |
|---|---|
| Pages (from-to) | 172-180 |
| Number of pages | 9 |
| Journal | Journal of Nuclear Materials |
| Volume | 435 |
| Issue number | 1-3 |
| DOIs | |
| State | Published - 2013 |
Funding
The authors acknowledge Kim Kriewaldt and Alicia Certain for their contributions at the UW Ion Beam Laboratory, Janelle Wharry for providing samples from the UM Ion Beam Laboratory and Jim Bentley for his assistance on the project. A portion of this research was conducted at the SHaRE user Facility, which is sponsored by the Division of Scientific User Facilities, Office of Basic Energy Sciences, US Department of Energy (DOE). A portion of this research utilized National Science Foundation (NSF) supported shared facilities at the University of Wisconsin. Experimental work was supported by the US DOE, Office of Nuclear Energy Nuclear Energy University Program (NEUP), award 10-172. Modeling work for D. Morgan was supported by US DOE, Office of Nuclear Energy, NEUP, award 10-888 and for L. Barnard by the Rickover Fellowship Program. Additional support was provided by the US DOE, Office of Nuclear Energy under DOE Idaho Operations Office Contract DE-AC07-051D14517, as part of an ATR-NSUF experiment.
| Funders | Funder number |
|---|---|
| Division of Scientific User Facilities | |
| Office of Basic Energy Sciences | |
| US Department of Energy | |
| U.S. Department of Energy | |
| Office of Nuclear Energy | DE-AC07-051D14517, 10-888 |
| Nuclear Energy University Program | 10-172 |
