The effective H permeability was determined in various body-centered cubic materials. The H diffusivity in 2.25Cr-1wt%Mo steel could be described by:

D (cm2/s) = 3.2 x 10-4 exp[-9.2(kJ/mol)/RT]

T.P.Perng, C.J.Altstetter: Metallurgical Transactions A, 1987, 17[11], 2086-90