Abstract
Additive manufacturing (AM) represents a promising technique to fabricate metallic alloys with greater control of the resulting material features as compared to traditional manufacturing routes. Recently, there is greater interest in AM research on 9 wt% Cr ferritic/martensitic (F/M) steels, which are commonly studied for use in the nuclear energy industry. This research aims to prove that wire arc AM can manufacture F/M steels with adequate mechanical properties in multiple processing atmospheres and aims to study how shielding gas composition can be leveraged during fabrication to induce specific precipitation pathways. The effect of shielding gas composition on MX (M=Nb and/or V, X[dbnd]C and/or N) carbonitride precipitation in a 9 wt% Cr ferritic/martensitic (F/M) steel alloy known as Grade 91 was studied using N2 and CO2 gas additions to an inert Ar shielding gas atmosphere during wire arc AM. The N and C atoms present in the processing atmospheres were absorbed into the melt pools during fabrication. Due to their differing affinities for precipitate-forming reactions, the varying levels of C and N between the samples contributed to differences in final carbonitride composition and morphologies. Such precipitate behavior is of interest as carbonitrides have been shown to contribute to increased mechanical performance. This increased performance was studied via electron microscopy and tested for strength, ductility, and fracture properties.
| Original language | English |
|---|---|
| Article number | 102854 |
| Journal | Additive Manufacturing |
| Volume | 56 |
| DOIs | |
| State | Published - Aug 2022 |
Funding
This manuscript has been authored in part 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 ). The work presented in this paper was supported by the U.S. Department of Energy ( DOE ), Office of Nuclear Energy (NE), Advanced Fuels Campaign, under Contract no. DE-AC05-00OR22725 with UT-Battelle, LLC. The FEI (now Thermo Fisher Scientific) Talos F200X instrument used in this work was provided by the Department of Energy, Office of Nuclear Energy, Fuel Cycle R&D Program and the Nuclear Science User Facilities. This research was also supported in part by an appointment for T.M. Kelsy Green to the NESLS Program at Oak Ridge National Laboratory and a Nuclear Regulatory Commission Faculty Development Grant under Award Number 31310019M0005 for Kevin G. Field. Research completed on the Tescan MIRA3 FEG SEM was performed at the Michigan Center for Materials Characterization (MC 2 ) at the University of Michigan-Ann Arbor. The authors would like to acknowledge conversations with Dr. Ying Yang from Oak Ridge National Laboratory for helpful insights on the precipitation behavior. The authors would also like to acknowledge Dr. Cyril Cayron for his immense help with the use of his program ARPGE. The work presented in this paper was supported by the U.S. Department of Energy (DOE), Office of Nuclear Energy (NE), Advanced Fuels Campaign, under Contract no. DE-AC05-00OR22725 with UT-Battelle, LLC. The FEI (now Thermo Fisher Scientific) Talos F200X instrument used in this work was provided by the Department of Energy, Office of Nuclear Energy, Fuel Cycle R&D Program and the Nuclear Science User Facilities. This research was also supported in part by an appointment for T.M. Kelsy Green to the NESLS Program at Oak Ridge National Laboratory and a Nuclear Regulatory Commission Faculty Development Grant under Award Number 31310019M0005 for Kevin G. Field. Research completed on the Tescan MIRA3 FEG SEM was performed at the Michigan Center for Materials Characterization (MC2) at the University of Michigan-Ann Arbor. The authors would like to acknowledge conversations with Dr. Ying Yang from Oak Ridge National Laboratory for helpful insights on the precipitation behavior. The authors would also like to acknowledge Dr. Cyril Cayron for his immense help with the use of his program ARPGE.
| Funders | Funder number |
|---|---|
| University of Michigan-Ann Arbor | |
| U.S. Department of Energy | |
| U.S. Nuclear Regulatory Commission | 31310019M0005 |
| Office of Nuclear Energy | DE-AC05-00OR22725 |
| Oak Ridge National Laboratory |
Keywords
- Additive manufacturing
- Isothermal heat treatments
- Mechanical properties (elevated-temperature deformation)
- Nitrides
- Precipitation strengthening
