Characteristics of radiation porosity and structural phase state of reactor austenitic 07C–16Cr–19Ni–2Mo–2Mn–Ti–Si–V–P–B Steel after neutron irradiation at a temperature of 440–600°C to damaging doses of 36–94 dpa

Abstract

The phase composition and the characteristics of vacancy voids in cold-worked steel 07C–16Cr–19Ni–2Mo–2Mn–Ti–Si–V–P–B (CW EK164-ID) after neutron irradiation at damaging doses of 36–94 dpa and temperatures of 440–600°C are investigated. In the entire range of damaging doses and temperatures, voids with different sizes are observed in the material. The maximum void size increases with irradiation temperature up to ~550°C, whereas their concentration decreases. At higher irradiation temperatures, almost no coarse voids are observed. The concentration of fine voids (to 10 nm in size) sharply increases with temperature from 440 to 480°C. Further increases in the temperature do not result in the noticeable concentration growth. In the irradiation temperature range of 440–515°C, second phases precipitate (G phase, γ’ phase, and complex fcc carbides). At higher irradiation temperatures, there are Laves-phase particles, fine second carbides of the MC type, and needle shape precipitates identified as phosphides in the material.