Fe的化学计量比对金属间化合物Ni_3Fe环境氢脆的影响

Influence of Fe Stoichiometry on Environmental Embrittlement of Ni_3Fe Intermetallics

研究不同Fe化学计量比的无序态、有序态金属间化合物Ni3Fe合金在真空和氢气环境中拉伸的力学性能和断口形貌.结果表明,当Ni3Fe合金的成分偏离化学计量比时,合金的相组成不发生变化,但合金的力学性能和在氢气环境中的氢脆敏感性却随之发生变化.非化学计量的Ni3Fe合金在真空和氢气中的塑性增加,氢脆因子(IH2)降低.不同Fe化学计量比的有序态Ni3Fe合金氢脆敏感性的差异与合金的有序度有关,化学计量的Ni3Fe合金有序度最高,环境氢脆敏感性也最高;非化学计量的Ni3Fe合金有序度降低,环境氢脆敏感性也随之降低.

Tensile properties and fractographic features of ordered and disordered NizFe alloys with different Fe stoichiometry tested in vacuum and gaseous hydrogen were investigated. The results show that the phase structure of the alloys does not change, but both tensile properties and sensitivity to H2-induced embrittlement change when the Ni3Fe alloy component deviates from stoichiometry. Compared with the stoichiometric Ni3Fe alloy, ductility of the non-stoichometric Ni3Fe alloys increases when tested both in vacuum and gaseous hydrogen. The hydrogen embrittlement factor （IH2） of the ordered alloys decreases when tested in gaseous hydrogen for the non-stoichiometric Ni3Fe alloys. The difference in sensitivity to environmental embrittlement depends on the degree of order for Ni3 Fe alloys with different stoichiometry. The ordered stoichiometric NiaFe alloy has the highest degree of order and is the most sensitive to environmental embrittlement among the used alloys. The degree of order and the sensitivity to environmental embrittlement decrease at the same time for the ordered non-stoichiometric Ni3 Fe alloy.