Effect of composition on hydrogen permeation in Fe–Al alloys

This paper presents the results obtained in the hydrogen permeation studies in Fe–24 wt%Al and Fe–24 wt%Al–1 wt%C intermetallic alloys. Electrochemical permeation technique was used to evaluate hydrogen permeability, apparent diffusivity and solubility. The results obtained were compared with those reported earlier for Fe3Al-based alloys. It was observed that increase in carbon and aluminum contents resulted in decrease of hydrogen permeability. The possible reasons for this are discussed. The improved machinability of carbon containing alloys may be related to a reduced susceptibility to hydrogen embrittlement in the presence of carbon.