NSUF 15-593: A study of the microstructural and mechanical effects of neutron irradiation dose and temperature on a series of Fe-Cr alloys
As part of an effort to understand the effect of neutron irradiation on various structural materials, a wide variety of alloys including a series of Fe-Cr samples (with 3-18%Cr) was inserted in the ATR and irradiated at different temperatures and to different doses. It has been observed in the Fe-Cr alloys irradiated to 1.8 dpa at 290?C that Cr starts to get segregated as ?? precipitates by an irradiation assisted process when the Cr content is more than 9 At% (Bachhav, et al, Scripta Materialia, 2013). The size, distribution and structure of these precipitates are important factors affecting the mechanical properties of these steels, and these are being currently investigated by the present researchers. We wish to build upon the existing knowledge of the Fe-Cr system by investigating the effect of higher dose and irradiation temperature on the microstructure and the mechanical properties of the samples irradiated to ~6 dpa at 400?C. The microstructural characterization will involve determination of the size, distribution, number density of Cr rich ?? precipitates, and the nature and number density of dislocation loops. For this purpose, we propose to carry out pre-fabrication of the TEM specimens to 1 ?m thickness (from all 6 irradiated samples in the batch (Packet 5-2) –Fe- 3%Cr, 6%Cr, 9%Cr, 12%Cr, 15%Cr and 18%Cr) in one of NSUF’s “Hot FIBs”. These samples will then be thinned to electron transparency and examined in the TEM at ANSTO. The investigation of mechanical property effects will be performed through in situ micro-compression testing inside the scanning electron microscope. In order to achieve this objective, we wish to prepare micro-compression specimens from all 6 irradiated samples in the batch using one of NSUF’s “Hot FIBs”. The fabricated micro pillars will be tested at the in situ testing facility available at ANSTO. This dual approach will give us a direct understanding of the effect of irradiation at 400?C to 6 dpa on the microstructure and mechanical properties of these alloys, and when compared with the results from similar examination of Fe-Cr alloys irradiated at 290?C to 1.8 dpa, shall provide a more comprehensive understanding of the effect of irradiation temperature and dose. Thus, the present study will be an important component in building a road-map for designing workable alloys based on these Fe-Cr model compositions for nuclear reactor applications.
Additional Info
| Field | Value |
|---|---|
| Abstract | As part of an effort to understand the effect of neutron irradiation on various structural materials, a wide variety of alloys including a series of Fe-Cr samples (with 3-18%Cr) was inserted in the ATR and irradiated at different temperatures and to different doses. It has been observed in the Fe-Cr alloys irradiated to 1.8 dpa at 290?C that Cr starts to get segregated as ?? precipitates by an irradiation assisted process when the Cr content is more than 9 At% (Bachhav, et al, Scripta Materialia, 2013). The size, distribution and structure of these precipitates are important factors affecting the mechanical properties of these steels, and these are being currently investigated by the present researchers. We wish to build upon the existing knowledge of the Fe-Cr system by investigating the effect of higher dose and irradiation temperature on the microstructure and the mechanical properties of the samples irradiated to ~6 dpa at 400?C. The microstructural characterization will involve determination of the size, distribution, number density of Cr rich ?? precipitates, and the nature and number density of dislocation loops. For this purpose, we propose to carry out pre-fabrication of the TEM specimens to 1 ?m thickness (from all 6 irradiated samples in the batch (Packet 5-2) –Fe- 3%Cr, 6%Cr, 9%Cr, 12%Cr, 15%Cr and 18%Cr) in one of NSUF’s “Hot FIBs”. These samples will then be thinned to electron transparency and examined in the TEM at ANSTO. The investigation of mechanical property effects will be performed through in situ micro-compression testing inside the scanning electron microscope. In order to achieve this objective, we wish to prepare micro-compression specimens from all 6 irradiated samples in the batch using one of NSUF’s “Hot FIBs”. The fabricated micro pillars will be tested at the in situ testing facility available at ANSTO. This dual approach will give us a direct understanding of the effect of irradiation at 400?C to 6 dpa on the microstructure and mechanical properties of these alloys, and when compared with the results from similar examination of Fe-Cr alloys irradiated at 290?C to 1.8 dpa, shall provide a more comprehensive understanding of the effect of irradiation temperature and dose. Thus, the present study will be an important component in building a road-map for designing workable alloys based on these Fe-Cr model compositions for nuclear reactor applications. |
| Award Announced Date | 2015-08-10T00:00:00 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Yaqiao Wu |
| Irradiation Facility | None |
| PI | Dhriti Bhattacharyya |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 593 |