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China's power industry has developed rapidly, and with the development of coal-fired power plants to the direction of the large-capacity high-parameter, resulting in most of the use of the environment of the metal material close to the ultimate conditions of use, which often cause accidents by corrosion, resulting in significant losses. Prevent as the main structural material of carbon steel corrosion in boiler water vapor system, to ensure the safe operation of the unit has an important significance. This article from reality, his main research work are: (1) the first power plant water vapor system with metal material and the process of development of the boiler hydraulic conditions, principle, the scope and the advantages and disadvantages of a simple generalization. (2) an overview of the temperature, anions, dissolved oxygen concentration, pH and oxidation film stability factors such as the impact of corrosion of carbon steel. To do more in-depth discussion on the role of the mechanism of corrosion of carbon steel Fe-H 2 O system. (3) According to the Fe-H 2 O system under high temperature chemical and electrochemical balance, draw potential-pH diagram at different temperatures. And on the type of pH adjusting agent, high temperature and the actual pH value of the solution under high temperature thermodynamic data were calculated and analyzed. The results show that with increasing temperature alpha-Fe 2 O 3 and Fe of 3 the O 4 of stability area to move to the direction of low pH, iron stable zone is reduced to negative potentials, alkaline corrosive area expansion. The type of pH adjusting agents, the ability to adjust the pH value in the high temperature type, wherein the weak ammonia to adjust the high-temperature aqueous solution of pH value, can be improved by adding sodium hydroxide. (4) coupon and electrochemical measurement method using autoclave temperature, dissolved oxygen concentration, pH, conductivity value of the solution and heated time and other factors on corrosion of carbon steel were studied. And potentiodynamic and AC impedance method to test the protective oxide film. The results showed that: the elevated temperature conducive to the generation of protective film, the corrosion rate decreases with increasing temperature; at room temperature with the pH value increased, the tendency of carbon steel surface passivation, corrosion rate decreases, the high temperature minimum pH value around 9.5 corrosion of carbon steel; higher the conductivity, the higher the pH, carbon steel passivation required; has a dual role of dissolved oxygen on the corrosion of carbon steel, high concentrations can promote the corrosion of carbon steel role in low concentrations conducive to the formation of the protective oxide film, corrosion inhibiting effect; electrochemical experimental results show that the higher the corrosion resistance of the film-forming test piece. (5) Finally, this paper preliminary outlook for carbon steel corrosion behavior in a weakly alkaline aqueous solution focus of future research.
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