Hydrogen embrittlement of commercial purity titanium

This paper presents a study of hydrogen embrittlement of commercial purity titanium. The first part of the results section considers gaseous hydrogen embrittlement of grade 2 titanium. This particular heat of material had been found to be very resistant to hydrogen cracking when tested in acidic salt water conditions. A thick hydride layer would form on the surface but this film had little effect on mechanical properties. However, when exposed to gaseous hydrogen at elevated temperatures this material readily formed hydrides and the material became very brittle. In addition to our discussion of these results we also present results for grade 4 titanium tested in sodium chloride solution and compare it with previously reported results on the grades 2 and 3 titanium. Of these three grades of titanium, only the grade 3 showed susceptibility to hydrogen embrittlement when tested in the sodium chloride environment. We suggest that the reason why this material was more susceptible to hydride formation and hydrogen embrittlement was because of the higher iron content of the grade 3 titanium.