The effect of cold work on H permeation in samples which contained 30 or 110ppmC was studied 273 to 333K by using an electrochemical permeation method. It was found that the H diffusivity in the fully annealed material was independent of the C content and could be described by:

D (cm2/s) = 7.69 x 10-4 exp[-1.38(kcal/mol)/RT]

On the other hand, the decrease in H diffusivity due to cold-work was much greater in specimens with a higher C content.

S.Hinotani, Y.Ohmori: Transactions of the Japan Institute of Metals, 1985, 26[9], 622-9