Abstract
Additively manufactured (AM) 316 stainless steel (SS) differs from its wrought counterpart in its unique dislocation cell structure and the presence of segregation and oxide particles at the cell walls. This work investigated the evolution of the microstructure in laser powder bed fusion (LPBF) 316L and 316H SS under in-situ 1 MeV Kr ion irradiation at 600 °C to 5 dpa, and ex-situ 4 MeV Ni ion irradiation at 300 °C and 600 °C from 0.2 dpa to 10 dpa, with a dose rate for all experiments of 10-3 dpa/s. The results reveal that the dislocation cell structure results in heterogeneous formation of dislocation loops and voids, particularly at 600 °C, where loops tend to form within the cell interiors while voids form at the cell boundaries. LPBF 316H has a reduced level of swelling compared to LPBF 316L due to prolonged incubation. Energy Dispersive X-ray Spectroscopy (EDS) mapping indicates Ni and Si segregation at void surfaces due to radiation-induced segregation. At 300 °C, where voids are absent, the distribution of dislocation loops and stacking fault tetrahedra appears to be uniform. Dislocation cell structures mostly disappeared by 2 dpa for all conditions in this work. M23C6 carbides were observed in LPBF 316H at 600 °C as early as 0.2 dpa, but not in LPBF 316L. Nanoindentation was performed to obtain the hardness of irradiated materials. This work illustrated the influence of additive manufacturing processes on microstructure evolution under irradiation, revealing the differences as well as the similarities as compared with wrought 316 SS, and the AM-related phenomenon that can potentially occur under neutron irradiation in nuclear reactors.
| Original language | English |
|---|---|
| Article number | 156044 |
| Journal | Journal of Nuclear Materials |
| Volume | 616 |
| DOIs | |
| State | Published - Oct 2025 |
Funding
This work was sponsored by the U.S. Department of Energy, Office of Nuclear Energy, Advanced Materials and Manufacturing Technologies (AMMT) program, under Contract No. DE-AC02-06CH11357 with Argonne National Laboratory, managed and operated by UChicago Argonne LLC, by UT-Battelle, LLC, under contract DE-AC05-00OR22725, and Battelle Energy Alliance LLC under contract DE-AC07-05ID14517. Dr. Thak Sang Byun and Dr. Caleb Massey from Oak Ridge National Laboratory are thanked for providing the materials used for this study. Dr. Robert Erck is thanked for providing the access of optical profilometer. Dr. Hi Vo and Dr. Matt Schneider were thanked for the advice in performing nanoindentation. Dr. Yuzi Liu was thanked for providing assistance in focused ion beam. Dr. Jianguo Wen and Mr. Hanyu Hou were thanked for EELS measurement. The Work performed at the Center for Nanoscale Materials, a U.S. Department of Energy Office of Science User Facility, was supported by the U.S. DOE Office of Nuclear Engineering, under Contract No. DE-AC02-06CH11357. This manuscript has been authored by UChicago Argonne LLC under Contract No. DE-AC02-06CH11357, by UT-Battelle, LLC, under contract DE-AC05-00OR22725, and Battelle Energy Alliance LLC under contract DE-AC07-05ID14517 with the U.S. Department of Energy. 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 ( https://www.energy.gov/doe-public-access-plan ).
Keywords
- Additive manufacturing
- Dislocation loops
- Irradiation effects
- Stainless steel
- Voids