NSUF 18-1203: Microstructure characterization of neutron-irradiated Fe-Cr-C model alloys
The objective of this research program is to establish the microstructure-property relationship by investigating the neutron radiation effects on the microstructure of Fe-Cr-C model alloys. The mechanical properties of these irradiated specimens have been obtained from previous 1) in situ synchrotron X-ray diffraction (XRD) tensile experiments and 2) nanoindentation experiments. Scanning transmission electron microscopy (STEM) will be employed to carry out the microstructure characterization. Dislocation loops play a major role in irradiation hardening, which is one of the biggest concerns for ferritic and ferritic/martensitic steels. This program is expected to provide critical microstructure information on the relationship between radiation-induced dislocation loops and irradiation hardening (increase in yield strength and nano-hardness) in neutron-irradiated Fe-Cr-C model alloys. Moreover, the results will be compared to neutron irradiation data of Fe-Cr binary model alloys under the same temperatures and doses so that the effect due to carbon can be identified. The introduction of carbon leads to the formation of carbides, and carbon atoms can decrease the mobility of point defects. It is thus expected that Fe-Cr-C model alloys will have different hardening behavior under irradiation. The stability of the carbides, elemental segregation at defect sinks (GBs, precipitates), and the loop size and density at several critical irradiation conditions will be obtained through (S)TEM investigation. The results will also be compared to neutron irradiation data of Fe-Cr model alloys and commercial F/M alloys that were irradiated in the same set of capsules, eliminating the differences due to irradiation conditions. The microstructure-property of neutron-irradiated Fe-Cr-C model alloys studied by this project will be a critical step towards filling the knowledge gap between Fe-Cr binary model alloys and Fe-Cr base commercial alloys such as T91. All 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.
Additional Info
| Field | Value |
|---|---|
| Abstract | The objective of this research program is to establish the microstructure-property relationship by investigating the neutron radiation effects on the microstructure of Fe-Cr-C model alloys. The mechanical properties of these irradiated specimens have been obtained from previous 1) in situ synchrotron X-ray diffraction (XRD) tensile experiments and 2) nanoindentation experiments. Scanning transmission electron microscopy (STEM) will be employed to carry out the microstructure characterization. Dislocation loops play a major role in irradiation hardening, which is one of the biggest concerns for ferritic and ferritic/martensitic steels. This program is expected to provide critical microstructure information on the relationship between radiation-induced dislocation loops and irradiation hardening (increase in yield strength and nano-hardness) in neutron-irradiated Fe-Cr-C model alloys. Moreover, the results will be compared to neutron irradiation data of Fe-Cr binary model alloys under the same temperatures and doses so that the effect due to carbon can be identified. The introduction of carbon leads to the formation of carbides, and carbon atoms can decrease the mobility of point defects. It is thus expected that Fe-Cr-C model alloys will have different hardening behavior under irradiation. The stability of the carbides, elemental segregation at defect sinks (GBs, precipitates), and the loop size and density at several critical irradiation conditions will be obtained through (S)TEM investigation. The results will also be compared to neutron irradiation data of Fe-Cr model alloys and commercial F/M alloys that were irradiated in the same set of capsules, eliminating the differences due to irradiation conditions. The microstructure-property of neutron-irradiated Fe-Cr-C model alloys studied by this project will be a critical step towards filling the knowledge gap between Fe-Cr binary model alloys and Fe-Cr base commercial alloys such as T91. All 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. |
| Award Announced Date | 2018-02-01T14:15:02.403 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Alina Zackrone |
| Irradiation Facility | None |
| PI | James Stubbins |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 1203 |