Single crystals and polycrystalline electrolytic material was studied. The diffusion coefficient was deduced, at temperatures of 233 to 303K, from the frequency-dependence of the phase difference between anodic permeation

current and cathodic charging current. The results could not be described by an Arrhenius relationship (figure 3). Trapping effects were significant, at low temperatures, in both polycrystalline and monocrystalline crystals.

Y.Hayashi, M.Nagano, N.Ohtani: Nippon Kinzoku Gakkaishi, 1980, 44[1], 48-52

 

Table 30

Apparent Diffusivities of H in Fe

of Various Degrees of Purity at 25C

 

Material

D (cm2/s)

high-purity (4N85) Fe

4.08 x 10-6

electrolytic (2N87) Fe, 400ppmO

2.8 x 10-6

electrolytic (2N87) Fe, 150ppmO

2.85 x 10-6

Armco (2N5) Fe

3.9 x 10-7

high-purity Fe, 0.04wt%Ni

4.56 x 10-6

electrolytic Fe, 0.09wt%Ni

1.34 x 10-6

high-purity Fe, 0.15wt%Ni

1.22 x 10-6

electrolytic Fe, 0.5wt%Ni

1.14 x 10-6

high-purity Fe, 0.9wt%Ni

9.8 x 10-7

electrolytic Fe, 1.7wt%Ni

8.07 x 10-7

electrolytic Fe, 2.5wt%Ni

8.2 x 10-7