Abstract
A lean duplex stainless steel material (2304-grade) in its base metal and electron beam (e-beam) welded conditions were studied microstructurally and mechanically as a function of irradiation conditions to evaluate its use as a structural material at low temperatures (60–100 °C). Neutron irradiation up to a fluence of 1.40 × 1019 n/cm2 (E > 0.1 MeV) or ~0.011 dpa decreased the total elongation of both base metal and e-beam welded samples. Overall, radiation hardening was observed in all the samples. The transversely cut irradiated samples showed some nonuniform quasi-cleavage and shearing in their fracture surfaces, indicating the variance of ductile nature of the two-phased (deformable austenite and harder ferrite) duplex structure. The e-beam welded samples also showed quasi-cleavage fracture, which is a characteristic of radiation-induced embrittlement. These observations of the e-beam welded samples were attributed to the formation of coarse ferrites, grain boundary and intragranular phases such as γ2 and γ3, and minor impurity phases such as CrN and Cr2N in the weld pool and/or heat-affected zone of the samples. Radiation-induced elemental segregation was also identified in the post-irradiated base metal.
Original language | English |
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Article number | 141780 |
Journal | Materials Science and Engineering: A |
Volume | 823 |
DOIs | |
State | Published - Aug 17 2021 |
Funding
Funding for this research work was provided by the US Department of Energy's National Nuclear Security Administration , DOE /NNSA), Office of Material Management and Minimization's Molybdenum-99 Program. This work was also performed under the auspices of the U.S. Department of Energy (DOE) by Lawrence Livermore National Laboratory (LLNL) under Contract No. DE-AC52-07NA27344. The authors would also like to thank their coworkers at ORNL for their support in this research work: Tom Geer, Christopher Stevens, Michael McAlister, Maxim Gussev, Pat Bishop, and Joel McDuffee. ** 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 ). Funding for this research work was provided by the US Department of Energy's National Nuclear Security Administration, DOE/NNSA), Office of Material Management and Minimization's Molybdenum-99 Program. This work was also performed under the auspices of the U.S. Department of Energy (DOE) by Lawrence Livermore National Laboratory (LLNL) under Contract No. DE-AC52-07NA27344. The authors would also like to thank their coworkers at ORNL for their support in this research work: Tom Geer, Christopher Stevens, Michael McAlister, Maxim Gussev, Pat Bishop, and Joel McDuffee.
Keywords
- Austenite
- Chromium nitride
- Duplex stainless steel 2304
- Ferrite
- Low temperature neutron irradiation
- e-beam welding