Abstract:Stem from its high specific strength, low density, low elastic modulus, excellent toughness, fatigue and corrosion resistance, titanium alloy has become a kind of attractive candidate material for oil country tubular goods(OCTG) and offshore components in harsh service environment. Because the oil gas exploration environment of China is more rigorous, certain titanium alloy OCTG will occur corrosion problems especially crevice corrosion, in this service environment, which will lead to the seal failure of titanium alloy OCTG premium connection and cause huge economic losses. In this paper, 5 kind typical titanium alloys materials((Ti-6Al-4V, Ti-6Al-4V-0.1Ru, Ti-6Al-2Sn-4Zr-6Mo,Ti-3Al-8V-6Cr-4Zr-4Mo and Ti-5.5Al-4.5V-2Zr-1Mo))used for oil gas exploration were investigated, the influence of different alloy compositions on anti-corrosion properties of these titanium alloys in China typical service environment were studied by high-temperature high-pressure autoclave simulation test, the corrosion morphology and corrosion products were also analyzed is analyzed and summarized by using scanning electronic microscopy (SEM)and energy dispersive spectrometer (EDS),the corrosion resistance mechanism of different alloys was discussed by electrochemical method. The results showed that the corrosion reactions of all titanium alloy materials were anode controlled under the test conditions, the uniform corrosion rates of all tested titanium alloy were lower than 0.001mm/a, and the resistance to stress corrosion cracking of all titanium alloys were excellent. However, Ti-6Al-4V and Ti-5.5Al-4.5V-2Zr-1Mo alloys had obvious pitting and crevice corrosion problems. The corrosion mechanism results showed that, under the test conditions, the self-corrosion potential, polarization resistance of all titanium alloys decreased and the corrosion current increased with the decrease of pH value, which illustrated that corrosion resistance of titanium alloys were reduced, especially for Ti-6Al-4V. The research results provide a theoretical basis for material selection and crack corrosion prevention of titanium alloy OCTG used in oil and gas exploration.