Electrochemical permeation experiments were performed on annealed samples (Pd-electroplated 0.7mm membranes) of 2N8-purity α-phase material in 0.1N NaOH electrolyte at temperatures of between 290 and 350K. It was found that the results could be described by the expression,
D (m2/s) = 5.12 x 10-8 exp[-4.32(kJ/mol)/RT]
The binding energy in the membranes was estimated to be 21.4kJ/mol, and was attributed to dislocation or grain boundary interactions with the permeating H.
An Improved Calculation Method of Hydrogen Diffusion Coefficient in Lattice of Metals. K.Yang, A.P.Xian, M.Z.Cau, X.J.Wan: Scripta Metallurgica, 1988, 22[3], 355-7
Table 45
Diffusion of H in Liquid Fe Alloys
Addition | C (at%) | T (C) | Do (cm2/s) | E (kcal/mol) |
- | 0 | 1550-1680 | 4.37 x 10-3 | 4.134 |
Ni | 5 | 1575-1650 | 4.66 x 10-3 | 4.509 |
Co | 5 | 1575-1650 | 4.76 x 10-3 | 4.382 |
Cu | 5 | 1575-1650 | 3.22 x 10-3 | 3.019 |
V | 5 | 1575-1650 | 2.70 x 10-3 | 2.860 |
Cr | 5 | 1575-1650 | 3.56 x 10-3 | 3.496 |
Nb | 5 | 1575-1650 | 2.00 x 10-3 | 2.880 |
Mo | 5 | 1575-1600 | 2.55 x 10-3 | 2.805 |
W | 5 | 1575-1600 | 2.93 x 10-3 | 3.458 |