An accepted practice is the use of inhibitors in the corrosion control of metals and its alloys which are in contact with any aggressive medium such as sea water. Inorganic and organic compounds have been studied for their corrosion control potential; these studies reveal that the inhibitors especially with the polar atoms such as P, N, S and O showed excellent inhibition efficiency (IE). The inhibitors adsorbed on the metal surface through the polar atoms; protective films are formed. The protective films have been analyzed by surface characterization studies such as UV, fluorescence spectra, FTIR, SEM, EDX, Raman spectroscopy, Auger electron spectroscopy, XRD, XPS and AFM. Adsorption of the inhibitors obeys various adsorption isotherms. The IE has been investigated by electrochemical studies such as polarization, impedance spectroscopy, open circuit potential and cyclic voltammetry, etc. The conclusion of this article gives vivid account of both inorganic and organic compounds which are used as corrosion inhibitors for various metals and its alloys in natural/artificial sea water medium.
Key words: corrosion, FTIR, SEM, AFM, inhibitor, sea water.
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