Material of 3N7-purity, with grain sizes ranging from 50 to 150μ, was charged with H and the diffusivity was determined by using an electrochemical method. It was found that both the lattice and grain boundary diffusion coefficients (table 105) were only slightly affected by aging treatments. The latter were expected to have some influence due to the resultant segregation of S.

Grain Boundary Transport of Hydrogen in Nickel. T.Tsuru, R.M.Latanision: Scripta Metallurgica, 1982, 16[5], 575-8

Figure 19

Diffusivity of H on the (100) Surface of Ni