The migration of H in annealed and cold-rolled samples, under varying cathodic current densities was studied at temperatures of between 279 and 335K (table 128) by using electrochemical techniques. In neither type of specimen did the activation energy for diffusion depend upon the H content beneath the cathodic surface. The average activation energy in the case of annealed material was 21.48kJ/mol. The corresponding value for cold-rolled material was slightly larger. The diffusion coefficient in the latter case was lower than that in annealed material, and increased with increasing H content.

Diffusivity and Solubility of Hydrogen in Annealed and Cold Rolled Specimens of Palladium. Y.Sakamoto, N.Tabaru: Journal of the Japan Institute of Metals, 1981, 45[10], 1048-55