A study was made of the permeation of H and D through a structural steel which contained 0.2 to 0.3C, 0.2 to 0.4Si and 0.5 to 0.8%Mn. At temperatures ranging from 600 to 850K, the activation energies for H and D permeation were 18 and 18.8kcal/mol, respectively. The H permeation rate was between 1.3 and 1.35 times higher than that of D. This was compared with the equivalent ratio of 1.41 for pure Fe.

V.J.Kosheleva, P.V.Geld, V.A.Goltsov, R.A.Ryabov: Metody Opred. Issled. Sostoyaniya Gazov Metal., 1968, 253-6

Table 49

Room-Temperature Diffusivity of H in 0.5%C Steel