Radiation response of alloy T91 at damage levels up to 1000 peak dpa Academic Article uri icon

abstract

  • 2016 Ferritic/martensitic alloys are required for advanced reactor components to survive 500600 neutron-induced dpa. Ion-induced void swelling of ferritic/martensitic alloy T91 in the quenched and tempered condition has been studied using a defocused, non-rastered 3.5MeV Fe-ion beam at 475C to produce damage levels up to 1000 peak displacements per atom (dpa). The high peak damage level of 1000dpa is required to reach 500600dpa level due to injected interstitial suppression of void nucleation in the peak dpa region, requiring data extraction closer to the surface at lower dpa levels. At a relatively low peak damage level of 250dpa, voids began to develop, appearing first in the near-surface region. With increasing ion fluence, swelling was observed deeper in the specimen, but remained completely suppressed in the back half of the ion range, even at 1000 peak dpa. The local differences in dpa rate in the front half of the ion range induce an internal temperature shift that strongly influences the onset of swelling, with shorter transient regimes resulting from lower dpa rates, in agreement not only with observations in neutron irradiation studies but also in various ion irradiations. Swelling was accompanied by radiation-induced precipitation of Cu-rich and Si, Ni, Mn-rich phases were observed by atom probe tomography, indicating concurrent microchemical evolution was in progress. In comparison to other ferritic/martensitic alloys during ion irradiation, T91 exhibits good swelling resistance with a swelling incubation period of about 400 local dpa.

published proceedings

  • JOURNAL OF NUCLEAR MATERIALS

author list (cited authors)

  • Gigax, J. G., Chen, T., Kim, H., Wang, J., Price, L. M., Aydogan, E., ... Shao, L.

citation count

  • 49

complete list of authors

  • Gigax, JG||Chen, T||Kim, Hyosim||Wang, J||Price, LM||Aydogan, E||Maloy, SA||Schreiber, DK||Toloczko, MB||Garner, FA||Shao, Lin

publication date

  • December 2016