A novel method was proposed for determining H diffusion in ductile metallic materials by means of cross-sectional microhardness profiling following cathodic H-charging. The H, in solid solution, strained the metallic lattice and resulted in an increased hardness. The increase in H concentration at a given depth below the surface could therefore be related to the microhardness increase at this location, as compared with the bulk value. The method was used to determine the H diffusivity in stoichiometric Fe3Al. The estimated H diffusivity was comparable with published data.

Determination of Hydrogen Diffusivity by Subscale Microhardness Profiling. R.Balasubramaniam: Journal of Alloys and Compounds, 1999, 293-295, 279-81