Hydrogen and Deuterium Transport through Type 304 Stainless Steel at Elevated Temperatures

Abstract

The permeation time-lag method have been used to determine the permeabilities, diffusion coefficients and solubilities of hydrogen and deuterium in type 304 stainless steel of three kinds of surface treated specimens; with oxide film, reduced by H2 gas and Pd coated. For the specimen with a thin oxide film the permeability increased abruptly at the temperature higher than 1,050 K owing to reduction of the oxide film by H2 gas introduced. The permeability and diffusion coefficient for hydrogen-reduced specimens agreed with those for Pd-coated specimens showing the data of bulk diffusion limited. The isotope effects for permeability ΦH/ΦD, diffusion coefficient D H/D D and solubility were about 1.4, 1.2 and 1.1, respectively. From these values θ(=hν/k)=1,530±50K and θ′(=hν/k)=2,740±20K were obtained by the quantum effect of a harmonic approximation.