Effect of hydrogen on room-temperature plasticity of B2 iron aluminides

Different sensitivities to hydrogen embrittlement for the disordered and ordered B2 FeAl alloys have been investigated. The plasticity of annealed alloys (before hydrogenating) has been found to decrease with increasing the long-range order parameter. An intrinsic weakness of FeAl phase grain boundaries revealed at a high degree of ordering. The results of bending tests on specimens annealed and cathodically charged with hydrogen have shown that the influence of hydrogen on the plasticity diminishes with the increase in the degree of FeAl phase ordering.

Research highlights
► The classical electrochemical method was used to carry out B2 FeAl alloys saturation with hydrogen.
► The plasticity of non-charged FeAl phase decreases with increasing the degree of long-range order.
► The deflection values of hydrogen-charged specimens are much smaller as compared to the annealed specimens.
► The influence of hydrogen on the plasticity diminishes with increase the degree of ordering FeAl phase.