Effect of alloy stoichiometry and boron doping on the H2-induced environmental embrittlement of Ni3Fe intermetallics

The effect of alloy stoichiometry and boron doping on the H2-induced environmental embrittlement of Ni3Fe intermetallic alloys was investigated at room temperature. The results show that the alloy stoichiometry of Ni3Fe does not affect the sensitivity to hydrogen embrittlement and that the H2-induced environmental embrittlement is also not related to the surface elemental segregation induced by long time ordering. The results also indicate that the boron doping can effectively suppress the H2-induced embrittlement of ordered Ni3Fe intermetallics. The beneficial effect of boron is believed to be due to its strong segregation to grain boundaries and the enhancement of the boundary cohesive strength of Ni3Fe alloys.