NSUF 16-694: Nanoindentation investigations of neutron-irradiated Fe-Cr-C ternary model alloys
The objective of this research program is to investigate the neutron irradiation effects on the mechanical properties of Fe-Cr-C ternary model alloys. The selected model alloys are Fe-9Cr-0.1C and Fe-12Cr-0.2C, the composition of which are similar to commercial alloys T91 and HT9, respectively. Nanoindentation will be carried out to characterize the mechanical properties such as hardness and Young’s modulus of the irradiated specimens. In total eight samples (four Fe-9Cr-0.1C and four Fe-12Cr-0.2C) will be examined. The nominal irradiation temperature for all samples are 300C and the doses are 0.01 dpa, 0.1 dpa, 0.5 dpa, and 1.0 dpa. The samples will be prepared using flash polishing. It is well known that for ferritic/martensitic (F/M) steels T91 and HT9, the most detrimental effects induced by irradiation are irradiation hardening and embrittlement, especially at lower temperatures such as 300C. The underlying mechanisms have not been well understood, due to the complicated microstructure and interactions under energetic neutron bombardment. Various irradiation-induced defects such as Cr-rich alpha prime, G phase, dislocation loops and networks contribute to the degradation in mechanical performance. This program seeks to advance the understanding of degradation mechanisms by quantify the irradiation effects in simple Fe-Cr-C model alloy systems so that effects due to other substitutional alloying elements are separated out. The experimental data from this program will be compared with (1) nanoindentation data of neutron-irradiated Fe-Cr binary model alloys studied in a previous research project, and (2) nanoindentation data of neutron-irradiated commercial alloys T91 and HT9 that are being investigated in another on-going research program supported by the Department of Energy. This research project on Fe-Cr-C ternary model alloys will contribute to the state-of-the-knowledge in three ways: (1) provide unique experimental data for advancing the understanding of neutron irradiation effects in Fe-Cr-C model alloys, (2) provide a basis for comparison with neutron irradiation results of Fe-Cr binary alloys, and (3) advance the understanding of radiation-induced degradation mechanisms in commercial alloys such as T91 and HT9. The neutron irradiation experiments have been completed and the samples are available for post-irradiation examination (PIE). All the PIE experiments are expected to be completed within the six-month period. Only nanoindenter is needed and the instrument time needed is estimated to be 8 days.
Additional Info
| Field | Value |
|---|---|
| Abstract | The objective of this research program is to investigate the neutron irradiation effects on the mechanical properties of Fe-Cr-C ternary model alloys. The selected model alloys are Fe-9Cr-0.1C and Fe-12Cr-0.2C, the composition of which are similar to commercial alloys T91 and HT9, respectively. Nanoindentation will be carried out to characterize the mechanical properties such as hardness and Young’s modulus of the irradiated specimens. In total eight samples (four Fe-9Cr-0.1C and four Fe-12Cr-0.2C) will be examined. The nominal irradiation temperature for all samples are 300C and the doses are 0.01 dpa, 0.1 dpa, 0.5 dpa, and 1.0 dpa. The samples will be prepared using flash polishing. It is well known that for ferritic/martensitic (F/M) steels T91 and HT9, the most detrimental effects induced by irradiation are irradiation hardening and embrittlement, especially at lower temperatures such as 300C. The underlying mechanisms have not been well understood, due to the complicated microstructure and interactions under energetic neutron bombardment. Various irradiation-induced defects such as Cr-rich alpha prime, G phase, dislocation loops and networks contribute to the degradation in mechanical performance. This program seeks to advance the understanding of degradation mechanisms by quantify the irradiation effects in simple Fe-Cr-C model alloy systems so that effects due to other substitutional alloying elements are separated out. The experimental data from this program will be compared with (1) nanoindentation data of neutron-irradiated Fe-Cr binary model alloys studied in a previous research project, and (2) nanoindentation data of neutron-irradiated commercial alloys T91 and HT9 that are being investigated in another on-going research program supported by the Department of Energy. This research project on Fe-Cr-C ternary model alloys will contribute to the state-of-the-knowledge in three ways: (1) provide unique experimental data for advancing the understanding of neutron irradiation effects in Fe-Cr-C model alloys, (2) provide a basis for comparison with neutron irradiation results of Fe-Cr binary alloys, and (3) advance the understanding of radiation-induced degradation mechanisms in commercial alloys such as T91 and HT9. The neutron irradiation experiments have been completed and the samples are available for post-irradiation examination (PIE). All the PIE experiments are expected to be completed within the six-month period. Only nanoindenter is needed and the instrument time needed is estimated to be 8 days. |
| Award Announced Date | 2016-08-16T13:00:35.65 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Peter Hosemann |
| Irradiation Facility | None |
| PI | James Stubbins |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 694 |