It was recalled that conventional methods, for the measurement of diffusion coefficients in various species of solids at high temperatures, were subject to various problems. These included the risk that adsorption and desorption of species from other parts of the apparatus could interfere with the results. In the present case, the diffusion coefficient was deduced from the decrease in both permeability and solubility which occurred when a well-defined part of the specimen was removed. The method was applied to the diffusion of H in various steels.

W.F.Caley, S.G.Whiteway: Canadian Metallurgical Quarterly, 1990, 29[4], 319-23

Figure 8

Diffusivity of H in Annealed 0.1%C Steel