Mechanism of corrosion of cast iron covered by aged corrosion products: Application of electrochemical impedance spectrometry

• Published in: Corrosion science Vol. 52; no. 4; pp. 1222 - 1227
• Main Authors: Sancy, M., Gourbeyre, Y., Sutter, E.M.M., Tribollet, B.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.04.2010; Elsevier
• Subjects: A. Iron; Applied sciences; B. EIS; B. Raman spectroscopy; C. Interfaces; C. Oxygen reduction; Cast iron; Chemical Sciences; Corrosion; Corrosion environments; Corrosion products; Diffusion; Diffusion layers; Drinking water; Exact sciences and technology; Impedance; Mass transfer; Metals. Metallurgy; B. Raman spectroscopy; C. Interfaces; A. Iron; C. Oxygen reduction; B. EIS; Cast iron; Corrosion product; Mechanism; Chemical reduction; Corrosion; Raman spectrometry; Impedance; Application; Interface; Iron; EIS; Raman spectroscopy; Interfaces; Oxygen reduction
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2009.12.026

This work focuses on the corrosion of cast iron in a drinking water network. The study is performed in water and in a sandy soil saturated with the same water. In the presence of corrosion products, the inner wall surface shows a lower corrosion rate than the external wall. In the two media, impedance diagrams are described by a high-frequency loop characteristic of a protective corrosion layer and a diffusion impedance loop at low frequencies associated with oxygen diffusion. Different models involving mass transfer through a porous layer are suggested for the inner and the external corrosion layers.