Hydrogen Permeability Of Ti - Zr And Nb - Ta 10-1-0.2 - Fe Alloy Organization And Performance

Titanium alloy is very easy to react with hydrogen, resulting in the changes of precipitation and processing performance. In order to further understanding the impact of hydrogen on Ti-25Nb-10Ta-1Zr-0.2Fe alloy, the influence of hydrogen on phase composition, microstructure evolution and mechanical properties were investigated by the means of optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM), HV test and Tensile test. Main conclusions were listed in the following:(1) The hydrogen solubility equation of Ti-25Nb-10Ta-1Zr-0.2Fe alloy at800℃to900℃wasHot-rolled alloy hydrogenated at900℃for one hour, whose hydrogen content was0.117wt%. Comparing with undrided alloy, the martensite amount of hydrogenated alloy increased from0to29%and the hardness increased by91%. The hydrogenation reduced the content of ω phase. After aging at350℃,450℃and550℃, hydrogenated alloy hardness remained unchanged, while unhydrided alloy hardness changed. Hydrogenation made hydrogen embrittlement. Comparing with undrided alloy, hydrogenated alloy’s tensile strengthes in solid solution state,450℃/30min aged state and550℃/30min aged state were decreased by60%,44%and33%, respectively.(2) After hydrogenating at570℃for two hours, the hydrogen content of the cold rolled alloy was0.2wt%, and its phases were β+α+δ+β’+δ. The needle-like δ phase was found at grain boundary.(3) The activation energy of co phase’s formation was decreased from154kJ/mol to38.7kJ/mol by0.117wt%H. Aging at350℃,450℃and550℃, the precipitation of a phase delayed by0.117wt%H.