The properties of corrosion product film formed on carbon steel in CO2-containing saltwater under the full pipe flow are examined by A. C. impedance methods. The effect of liquid velocity on the corrosion product film is discussed in this work. It is found that, for each velocity, there is a potential above which a diffusion process occurs on the electrode, and the Warburg impedance coefficient increases with increasing potential. It is suggested that the corrosion product film formed on the surface of the steel is porous, and the diffusion process occurs through the pores of the film. By calculation of the Warburg impedance coefficient ...
Keywords: Carbon steel, CO2 corrosion, Corrosion product film, pipelines, Liquid velocity, Electrochemical Impedance Spectroscope