PERMEATION AND DIFFUSION OF HYDROGEN AND DEUTERIUM IN 310 STAINLESS-STEEL, 472-K TO 779-K

The permeabilities and true lattice diffusivities of hydrogen and deuterium in 310 austenitic stainless steel were measured over 472 to 779 K with an ultrahigh vacuum, monopole gas analyzer system. The permeation activation energies for hydrogen and deuterium were virtually equal at 56,560 ± 2800 and 55,840 ± 3300 J/mol, respectively. Likewise, the diffusion activation energies for hydrogen and deuterium were essentially equal at 48,820 ± 920 and 48,070 ± 710 J/mol, respectively and were indicative of true lattice diffusion. Evaluation of the permeability coefficients and the true lattice diffusivities gave isotope ratios, 1.44 ± 0.14 and 1.38 ± 0.14, respectively, which indicates the mass effect to be confined to diffusivity and in agreement with the isotope ratio of 1.41 as predicted by classical theory. © 1979 American Society for Metals and the Metallurgical Society of AIME.