Microstructure-mechanical properties correlation of irradiated conventional and reduced-activation martensitic steels
- Oak Ridge National Lab., TN (United States)
- National Tsing Hua Univ. (Taiwan, Province of China)
Tensile, Charpy, and transmission electron microscopy specimens of two conventional steels, modified 9Cr-1Mo (9Cr-1MoVNb) and Sandvik HT9 (12Cr-1MoVW), and two reduced-activation steels, Fe-9Cr-2W-0.25V-0.1C (9Cr-2WV) and Fe-9Cr-2W-0.25V-0.07Ta-0.1C (9Cr-2WVTa), were irradiated in the Fast Flux Test Facility. Before irradiation, M{sub 23}C{sub 6} was the primary precipitate in all four steels, which also contained some MC. Neutron irradiation did not substantially alter the M{sub 23}C{sub 6} and MC. No new phases formed during irradiation of the 9Cr-2WV and 9Cr-2WVTa, but chi-phase precipitated in the 9Cr-1MoVNb and chi-phase and {alpha}{prime} precipitated in the 12Cr-1MoVW. Irradiation-produced dislocation loops were observed in 9Cr-2WV, 9Cr-2WVTa, and 12Cr-1MoVW. The irradiation-produced microstructural changes caused the steels to harden, as measured by the change in yield stress. Hardening was correlated with a change in the Charpy impact properties of 9Cr-1MoVNb, 12Cr-1MoVW, and 9Cr-2WV. Although irradiation caused a yield stress increase of the 9Cr-2WVTa similar to that for 9Cr-2WV and 9Cr-1MoVNb, the change in Charpy properties was considerably less for 9Cr-2WVTa. This difference in Charpy behavior of the 9Cr-2WVTa with that of the 9Cr-2WV and 9Cr-1MoVNb was attributed to differences in the fracture stress-temperature relationship and/or the flow stress-temperature relationship between the 9Cr-2WVTa and the other two 9Cr steels.
- Research Organization:
- Oak Ridge National Lab., TN (United States)
- OSTI ID:
- 47739
- Report Number(s):
- DOE/ER--0313/16; ON: DE95003404
- Country of Publication:
- United States
- Language:
- English
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