Microstructure and mechanical properties of austenitic stainless steel 12X18H9T after neutron irradiation in the pressure vessel of BR-10 fast reactor at very low dose rates

Results are presented for void swelling, microstructure and mechanical properties of Russian 12X18H9T (0.12C–18Cr–9Ni–Ti) austenitic stainless steel irradiated as a pressure vessel structural material of the BR-10 fast reactor at ∼350 °C to only 0.64 dpa, produced by many years of exposure at the very low displacement rate of only 1.9 × 10−9 dpa/s. In agreement with a number of other recent studies it appears that lower dpa rates have a pronounced effect on the microstructure and resultant mechanical properties. In general, lower dpa rates lead to the onset of swelling at much lower doses compared to comparable irradiations conducted at higher dpa rates.