Corrosion Process of API X52 Carbon Steel Immersed in an Aqueous Solution Simulating a Clay Soil

• Published in: Corrosion (Houston, Tex.) Vol. 67; no. 11; pp. 116001 - 116001-10
• Main Authors: COSMES LOPEZ, L. J, ARCE, E, TORRES, J, VAZQUEZ-ARENAS, J, HALLEN, J. M, CABRERA-SIERRA, R
• Format: Journal Article
• Language: English
• Published: Houston, TX NACE International 01.11.2011
• Subjects: Analytical methods; Applied sciences; Aqueous solutions; Buried pipes; Buried structures; Carbon steel; Carbon steels; Cathodic protection; Chemical composition; Chloride; Clay; Clay soils; Corrosion; Corrosion environments; Corrosion potential; Corrosion products; Electrochemical impedance spectroscopy; Electrochemistry; Electrodes; Electron microscopy; Exact sciences and technology; Experiments; Goethite; Humidity; Iron compounds; Magnetite; Metals. Metallurgy; Morphology; Nucleation; Oxidation; Oxygen; Polarizability; Roughness; Scanning electron microscopy; Soil; Soils; Spectroscopy; Spectrum analysis; Steel; Submarine pipelines; Submerging; Sulfates; Time dependence; Voltammetry; X-ray diffraction; Mexico; electrochemical impedance spectroscopy; Corrosion; Carbon steel; Aqueous solution; clay soil; Impedance; API X52 carbon steel
• ISSN: 0010-9312; 1938-159X
• DOI: 10.5006/1.3659506

Linear sweep voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy, and x-ray diffraction techniques were used to characterize the corrosion process of API X52 steel in a solution simulating clay soil. Likewise, the formation of the corrosion products that modify their chemical composition and roughness as a function of the immersion time as a result of the presence of molecular oxygen, chloride, and sulfate ions was analyzed. It was observed that these species induce the nucleation and growth of the pitting damage. This time-dependent phenomenon enhances the steel oxidation and is responsible for the formation of magnetite, maghemite, lepidocrocite, and goethite on the steel surface. These iron compounds are important because of their semiconductor properties that may affect the polarizability of the structure of buried pipelines in different ways.