Abstract
W-coated reduced activation ferritic steels have been developed for use as plasma facing components in fusion reactor blankets, offering excellent sputtering resistance and structural strength. Previous high-temperature coating methods, such as diffusion bonding and brazing, caused interfacial deterioration due to thermal stress from mismatched thermal expansion between W and reduced activation ferritic steel. To address this, underwater explosive welding was introduced as a high-velocity cold process that joins dissimilar materials while maintaining a strong, thin interface without the thermal issues associated with traditional methods. In this study, the effects of neutron irradiation on the hardness and microstructure in W-coated F82H reduced activation ferritic steel (W/F82H) joined by underwater explosive welding are investigated. Following neutron irradiation at 290 °C, irradiation hardening is suppressed in W, F82H, and their interface within the W/F82H material. Furthermore, microstructural observations indicate that the recovery of work hardening and relaxation of elastic strain introduced during coating significantly contribute to the suppression of irradiation hardening in W/F82H. In conclusion, W/F82H exhibits significantly suppressed irradiation hardening compared with those in stand-alone materials. This suppression is explained by residual stress from thermal expansion mismatch and the unique microstructure at the interface. These results provide valuable insights for the development of more durable materials in nuclear fusion applications.
| Original language | English |
|---|---|
| Article number | 155657 |
| Journal | Journal of Nuclear Materials |
| Volume | 607 |
| DOIs | |
| State | Published - Mar 2025 |
Funding
This study was supported by the JSPS KAKENHI (grant number: 23K25849). Research on the BR2 and post-irradiation experiments were performed under the GIMRT Program of the Institute for Materials Research, Tohoku University (proposal numbers: 202212-IRKMA-0408 and 202312-IRKMA-0403). Research on the HFIR and post-irradiation experiments in ORNL were conducted under the Japan-US FRONTIER collaboration, supported by the Ministry of Education, Culture, Sports, Science and Technology, Japan and US Department of Energy, Office of Science, Fusion Energy Sciences. ORNL research was partially sponsored by the US Department of Energy, Office of Fusion Energy Sciences, Fusion Materials Program, under contract DE- AC05–00OR22725 with UT-Battelle LLC. A portion of this research used resources at the HFIR, a US Department of Energy Office of Science User Facility operated by ORNL. This work was partly supported by the ZE Research Program, IAE (ZE2024A-04), Kyoto University. This study was supported by the JSPS KAKENHI (grant number: 23K25849). Research on the BR2 and post-irradiation experiments were performed under the GIMRT Program of the Institute for Materials Research, Tohoku University (proposal numbers: 202212-IRKMA-0408 and 202312-IRKMA-0403). Research on the HFIR and post-irradiation experiments in ORNL were conducted under the Japan-US FRONTIER collaboration, supported by the Ministry of Education, Culture, Sports, Science and Technology, Japan and US Department of Energy, Office of Science, Fusion Energy Sciences. ORNL research was partially sponsored by the US Department of Energy, Office of Fusion Energy Sciences, Fusion Materials Program, under contract DE- AC05–00OR22725 with UT-Battelle LLC. A portion of this research used resources at the HFIR, a US Department of Energy Office of Science User Facility operated by ORNL. Notice: This manuscript has been co-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 ).
Keywords
- Coating
- Explosive welding
- Ferritic steel
- Interface
- Irradiation hardening
- Joining
- Microstructure
- Tungsten