Abstract
F82H is the Japanese reference reduced-activation ferritic-martensitic (RAFM) steel for fusion blanket applications. The harsh environment of a fusion reactor, such as neutron irradiation and He/H damage, can result in significant degradation of F82H fracture toughness. Therefore, understanding the fracture toughness behavior of F82H in the fusion environment is critical to ensure the long-term safe operation of the fusion reactor. In this paper, we summarize seven irradiation campaigns of the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) covering five variants of F82H steels, including F82H IEA, F82H Mod3, F82H doped with 1.4% natural Ni, F82H doped with 1.4% 58Ni, and F82H doped with 1.4% 60Ni. The irradiation temperatures covered the range from 220 °C to 530 °C and the neutron irradiation dose spanned 4 dpa to 70 dpa. The effects of neutron irradiation temperature, dose, materials composition, Ni doping, and He production on F82H fracture toughness are discussed. Our results showed that irradiation embrittlement monotonically decreased with increasing irradiation temperature until 400 °C for F82H IEA and F82H Mod3. F82H Mod3 showed better fracture toughness than F82H IEA both before and after neutron irradiation. We determined that 1.4% Ni alloying can be applied to F82H for simulating He effect in a fission reactor without jeopardizing the fracture toughness of the material. However, more studies are needed to understand the effect of high dose (>20 dpa) and He production on F82H fracture toughness.
| Original language | English |
|---|---|
| Article number | 152501 |
| Journal | Journal of Nuclear Materials |
| Volume | 542 |
| DOIs | |
| State | Published - Dec 15 2020 |
Funding
This study was supported by the U.S. Department of Energy , Office of Fusion Energy Sciences and the National Institutes for Quantum and Radiological Science and Technology (QST) under contract DE-AC05-00OR22725 with Oak Ridge National Laboratory (ORNL) managed by UT Battelle, LLC. A portion of this research at ORNL's High Flux Isotope Reactor was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy. The authors would like to thank Eric Manneschmidt and Ronald Swain from ORNL for performing part of mechanical testing in this study. Besides, we are grateful for the hot cell testing support from the ORNL Irradiated Materials Examination and Testing Facility (IMET) team. This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).
| Funders | Funder number |
|---|---|
| National Institutes for Quantum | |
| Radiological Science and Technology | |
| Scientific User Facilities Division | |
| U.S. Department of Energy | |
| Basic Energy Sciences | |
| Fusion Energy Sciences | |
| Oak Ridge National Laboratory | |
| UT-Battelle | |
| National Institutes for Quantum and Radiological Science and Technology | DE-AC05-00OR22725 |
| National Institutes for Quantum and Radiological Science and Technology |
Keywords
- F82H
- Fracture toughness
- He effect
- Irradiation embrittlement
- Ni doping
- Reduced activation ferritic-martensitic steel
