engleski

Corrosion Inhibition of the Low Alloyed CrMo Steel

Corrosion problems in the oil and petrochemical industry have usually been solved by selection of suitable materials and/or by changing the environment to make it less aggressive. In this work the protective action of propargylic alcohol (PA), as corrosion inhibitor of the low alloy CrMo steel dissolution in 0.5 M H_2SO_4 solution, was studied by DC-polarization and AC-impedance spectroscopy measurements. According to the results of polarization measurements, propargylic alcohol could be treated as a mixed type inhibitor. Impedance spectroscopy showed that the inhibitor adsorption was specific, decreased surface heterogeneity and caused formation of the protective surface film. The inhibition process was treated as the substitutional adsorption process. Standard free energy of adsorption calculated on the basis of DC-polarization and AC-impedance measurements at the open circuit potential E_oc, using Flory-Huggins isotherm, was -15 kJmol^-1. The number of replaced water molecules, obtained after planar orientation of adsorbed PA molecule, was 3.

low alloyed CrMo steel; corrosion inhibition; adsorption; propargylic alcohol; impedance spectrosopy; voltammetry

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