By using a sensitive electrochemical technique, diffusion and permeation at temperatures ranging from 27 to 75C were found to be described by activation energies of 8.8 and 7.9kcal/g-atom, respectively.

The Electro-Permeation of Hydrogen into Metals. J.O.Bockris, M.A.Genshaw, M.Fullenwider: Electrochimica Acta, 1970, 15[1], 47-60