NSUF 21-4352: Ion Irradiation and examination of 304 Stainless Steel and 304 ODS Steel Additively Manufactured via Selective Laser Melting
Oxide dispersion strengthened (ODS) alloys are promising candidates for advanced nuclear reactors due to the presence of a high number density (~1024 m-2) of small (5-50 nm) oxide particles such as alumina (Al2O3) or yttria (Y2O3) dispersed within a metallic matrix. Conventional manufacturing of ODS alloy includes numerous steps such as long hours of mechanical alloying followed by canning, degassing, and hot extrusion or hot isostatic pressing making scale-up manufacturing of these alloys extremely unviable. Our approach was to utilize additive manufacturing (AM) via selective laser melting to eliminate mechanical alloying and significantly reduce the numerous steps in manufacturing. 304L stainless steel powder was mixed with 0.5 wt% Y2O3 and used as a powder bed in selective laser melting. Components were addictively manufactured at power of 105W and scanning speed of 50-600 mm/s. Microstructural characterization showed the presence of nanoparticles enriched in Yi-Si-O dispersed in 304L matrix implying manufacturing of 304L ODS alloy in one single step. The yield strength of additively manufactured 304L ODS at 800°C was 145±5 MPa with an elongation of 18.5±1%. 304L ODS alloy was successfully manufactured via selective laser melting. This is transformational progress on scale-up manufacturing of near-net-shape ODS alloys without the numerous steps involved in solid-state powder metallurgy. The creep data obtained at 700°C under 70, 100 and 130 MPa showed that the minimum creep rate at 100 MPa was found to be about two orders of magnitude lower than found in the literature for wrought 304L stainless steel. For this project, 3.0 MV NEC tandem accelerator at TAMU will be used for high dpa Fe self-ion irradiation. Irradiation will be performed in a high vacuum chamber along the beamline equipped with liquid nitrogen trap and multiple beam deflection setups for filtering contaminants. ODS samples will be irradiated by 5 MeV Fe self-ions for doses equivalent to 25, 50 and 100 dpa at 300°C. The doses will be determined by using SRIM code under KP mode. Post irradiation examination will include detailed microstructural studies using TEM and performing a nanoindentation test. The timeline for performing irradiation and post-irradiation examination will be between July and September 2021. The scientific outcome will be our understanding of the irradiation performance of 304L stainless steel and novel 304L ODS alloys additively manufactured via selective laser melting.
Additional Info
| Field | Value |
|---|---|
| Abstract | Oxide dispersion strengthened (ODS) alloys are promising candidates for advanced nuclear reactors due to the presence of a high number density (~1024 m-2) of small (5-50 nm) oxide particles such as alumina (Al2O3) or yttria (Y2O3) dispersed within a metallic matrix. Conventional manufacturing of ODS alloy includes numerous steps such as long hours of mechanical alloying followed by canning, degassing, and hot extrusion or hot isostatic pressing making scale-up manufacturing of these alloys extremely unviable. Our approach was to utilize additive manufacturing (AM) via selective laser melting to eliminate mechanical alloying and significantly reduce the numerous steps in manufacturing. 304L stainless steel powder was mixed with 0.5 wt% Y2O3 and used as a powder bed in selective laser melting. Components were addictively manufactured at power of 105W and scanning speed of 50-600 mm/s. Microstructural characterization showed the presence of nanoparticles enriched in Yi-Si-O dispersed in 304L matrix implying manufacturing of 304L ODS alloy in one single step. The yield strength of additively manufactured 304L ODS at 800°C was 145±5 MPa with an elongation of 18.5±1%. 304L ODS alloy was successfully manufactured via selective laser melting. This is transformational progress on scale-up manufacturing of near-net-shape ODS alloys without the numerous steps involved in solid-state powder metallurgy. The creep data obtained at 700°C under 70, 100 and 130 MPa showed that the minimum creep rate at 100 MPa was found to be about two orders of magnitude lower than found in the literature for wrought 304L stainless steel. For this project, 3.0 MV NEC tandem accelerator at TAMU will be used for high dpa Fe self-ion irradiation. Irradiation will be performed in a high vacuum chamber along the beamline equipped with liquid nitrogen trap and multiple beam deflection setups for filtering contaminants. ODS samples will be irradiated by 5 MeV Fe self-ions for doses equivalent to 25, 50 and 100 dpa at 300°C. The doses will be determined by using SRIM code under KP mode. Post irradiation examination will include detailed microstructural studies using TEM and performing a nanoindentation test. The timeline for performing irradiation and post-irradiation examination will be between July and September 2021. The scientific outcome will be our understanding of the irradiation performance of 304L stainless steel and novel 304L ODS alloys additively manufactured via selective laser melting. |
| Award Announced Date | 2021-06-07T16:13:29.353 |
| Awarded Institution | Idaho National Laboratory |
| Facility | Advanced Test Reactor |
| Facility Tech Lead | Alina Zackrone, Lin Shao, Yaqiao Wu |
| Irradiation Facility | Accelerator Laboratory |
| PI | Somayeh Pasebani |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 4352 |