An effect of gamma-neutron irradiation and oxygen admixtures on interaction of hydrogen with austenitic 18Cr–10Ni–Ti steel

Experimental data on permeability and diffusion of hydrogen through austenitic 18Cr–10Ni–0.65Ti steel with 0.08 and 0.12 wt.% of carbon have been obtained with special equipment designed and installed at the research reactor IVV-2M. It has been shown that parameters of hydrogen isotope transfer in the steel increased substantially during irradiation by fast neutrons of flux density ffast<1.8×1018 n m−2 per s, fluence F=9.5×1024 n m−2 (E>0.1 MeV) and absorbed gamma dose 3.6 W g−1 at temperatures of 573–1073 K. Under these irradiation conditions, even a small oxygen admixture content in hydrogen allowed creation of reliable surface barriers on the steel, which essentially decreased hydrogen permeability. At the same time, the physico-mechanical properties of the steel under study changed.