Hydrogen permeation studies were made of Fe–24wt%Al and Fe-24Al-1wt%C intermetallic alloys. An electrochemical permeation technique was used to evaluate the H permeability, apparent diffusivity and solubility. These results were compared with those reported for Fe3Al-based alloys. It was observed that an increase in the C and Al contents resulted in a decrease in H permeability. The improved machinability of C-containing alloys was suggested to be related to a reduced susceptibility to H embrittlement in the presence of C.

Effect of Composition on Hydrogen Permeation in Fe–Al Alloys. U.Prakash, N.Parvathavarthini, R.K.Dayal: Intermetallics, 2007, 15[1], 17-9