A study was made of the diffusion of H by using a Sieverts cell at 1080-1400C and 1atm. It was found that  the results could be described by:

D (cm2/s) = 4.68 x 10-3 exp[-7.62(kcal/g-atom)/RT]

H.Schenck, K.W.Lange: Archiv für Eisenhüttenwesen, 1966, 37[10], 809-12