Abstract
Tensile and Charpy specimens of four normalized-and-tempered martensitic steels were irradiated to 23-33 dpa at 376-405 °C in the Experimental Breeder Reactor (EBR-II). The steels were the ORNL reduced-activation steel 9Cr-2WVTa and that containing 2% Ni (9Cr-2WVTa-2Ni), modified 9Cr-1Mo (9Cr-2WVTa), and Sandvik HT9 (12Cr-1MoVW). Two tempering conditions were used for 9Cr-2WVTa and 9Cr-2WVTa-2Ni: 1 h at 700 °C and 1 h at 750 °C. The 9Cr-1MoVNb and 12Cr-1MoVW were tempered 1 h at 760 °C. These heat treatments produced tempered-martensite microstructures for all steels except 9Cr-2WVTa-2Ni tempered at 750 °C, where a duplex structure of tempered and untempered martensite formed. Based on changes in tensile and Charpy impact properties, the results demonstrated the superiority in strength and ductility of the 9Cr-2WVTa reduced-activation steel over the commercial steels. Comparison of the mechanical properties after irradiation of 9Cr-2WVTa-2Ni and 9Cr-2WVTa steels indicated a favorable effect of nickel that could lead to development of a heat treatment for improved irradiation resistance.
| Original language | English |
|---|---|
| Pages (from-to) | 220-228 |
| Number of pages | 9 |
| Journal | Journal of Nuclear Materials |
| Volume | 374 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - Feb 29 2008 |
Funding
We wish to thank L.T. Gibson, E.T. Manneschmidt and J.L. Bailey for carrying out the experimental tests, J.R. Mayotte for metallography, and Drs T.S. Byun and J.T. Busby for reviewing the manuscript. This research was sponsored by the Office of Fusion Energy Sciences, US Department of Energy, under contract DE-AC05-00OR22725 with U.T.-Battelle, LLC.