The formation mechanism of corrosion scale and electrochemical characteristic of low alloy steel in carbon dioxide-saturated solution

• DOI: 10.1016/j.corsci.2011.12.025
• Publication Date: 2012-01-02T06:54:29Z
• Authors: J.B. Sun; G.A. Zhang; W. Liu; M.X. Lu
• Keywords: Carbon steel; Alloy steel

Abstract The formation mechanism of corrosion scale and electrochemical characteristic of low alloy steel in CO 2 -saturated solution were investigated by electrochemical measurements and surface characterization. The results show that the electrochemical behavior is associated with the formation of corrosion scale and the microstructure of steel. At the initial polarization stage, ferrite dissolves preferentially and leaves Fe 3 C behind, which results in high Fe 2+ ions concentration between lamellar Fe 3 C. This situation facilitates the formation of FeCO 3 scale between the lamellar Fe 3 C. With further increase of polarization times, the whole electrode surface is covered by FeCO 3 scale.