Study of Inhibitor Containing Ti Through Exposed Experiment and Analysis of Surface Film for Nuclear Steam Generator

Corrosion of construction material in high temperature water is one of important problems for nuclear reactors. Latest researches show that TiO₂ inhabiting species can alleviate local corrosion, such as Stress Corrosion Cracking （SCC） and Inter-granular Attack （IGA） of steam generator tubes, prolong the life of SG tube. The result of high temperature exposed experiments shows that TiO₂ have positive effect. No SCC was found in 0Cr18Ni10Ti stainless steel after exposure to the 50% caustic solution with inhibitor containing Ti at 288℃ for 1 week. Among them, Rutile and Anatase are more effective than tetrabutyl titanate. But during a longer time （above 2 weeks） of experiment, the inhibitors containing Ti can not prevent SCC. SEM, XRD, XPS were used to analyze the chemical composition and construction of the film formed on the surface of the specimen, and the issue of dealloying was discussed. Depth sputtered XPS figure shows that Anatase can prevent dealloying and control the development of crack along inter-granular. TiO₂ inhabiting species is a new type granular inhibitor, and its application is being paid close attention.