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Inhibition of carbon steel corrosion in media with H 2 S studied by impedance spectroscopy method
Author(s) -
Tsygankova Liudmila E.,
Vigdorovich Vladimir I.,
Kichigin Vladimir I.,
Kuznetsova Ekaterina
Publication year - 2008
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.2710
Subject(s) - dielectric spectroscopy , chemistry , corrosion , alkyl , carbon steel , electrochemistry , hydrogen sulfide , polarization (electrochemistry) , cathodic protection , anode , amine gas treating , adsorption , analytical chemistry (journal) , sulfide , inorganic chemistry , nuclear chemistry , electrode , organic chemistry , sulfur
Investigations of carbon steel corrosion were conducted in the model stratum water saturated with hydrogen sulfide. Inhibitive properties of AMDOR IC‐6, that is, mixture of 10% aminoparafine C 12 C 18 and 10% imidazoline dissolved in specific mixture of organic solvents, EM‐10 (imino‐bis‐[(ethyl‐2)‐( C ‐alkyl of tall oil acids)‐(1,3‐diazocyclopenten‐2)]) and EM‐11 (1‐(3,6‐diazo‐8‐amine)‐( C ‐alkyl of coco oil acids)‐1,3‐diazocyclopenten‐2) have been studied by the electrochemical impedance spectroscopy (EIS) and for comparison by the weight loss and polarization measurements. The inhibitor concentration was equal to 25–200 mg/l. EIS measurements (60 kHz–10 mHz) were carried out at the corrosion potential ( E cor ), anodic and cathodic polarization. The suggested equivalent circuit consists of four parallel branches and satisfactorily fits the experimental data obtained in the solutions with and without the inhibitors at E cor . The observed values of double layer capacity C dl < 1 µF/cm 2 testify that multilayer adsorption of the inhibitors takes place on the electrode surface. It causes a retardation of the anodic reaction and slightly influences the cathodic one. Inhibitor efficiencies calculated on basis of impedance data qualitatively correlate with those obtained from the weight loss tests and the polarization measurements. Copyright © 2008 John Wiley & Sons, Ltd.