Effect of hydrogen treatment on structure and phase state and hydrogen permeability of low-activation 10Cr12Mn20W and 10Cr9WVA steels

Phase composition, hydrogen diffusion parameters (permeability, solubility, and diffusion coefficient) and electro-physical properties of low-activation 10Cr12Mn20W and 10Cr9WVA steels were studied in 673–1173 K temperature range in the initial normalized state and after isothermal annealing in vacuum and hydrogen under 873 K for 600 h. It is shown that thermal treatment decreases hydrogen permeability in 10Cr12Mn20W steel and increases it in 10Cr9WVA steel. Hydrogen flux in 10Cr9WVA ferritic/martensitic steel increases due to hydrogen decarbonization, this agrees with electrical and magnetic property changes under hydrogen treatment. Permeability of tritium through the analyzed steels is estimated and compared with the values for 2.25Cr–1Mo, 9Cr–1Mo and 316 steels.