Effect of an Imidazoline [IM-NH17] on the Corrosion Process of API5l-X52 Steel Exposed in Acidified Brines

Abstract

The inhibition effect of an aminoethyl oleic imidazoline [IM-NH17]) on the corrosion of API5L-X52 steel in acidified 5% NaCl pH 3 solutions at 50ºC was studied via electrochemical methods, i.e. potentiodynamic polarization tests and linear polarization resistance measurements. Polarization curves revealed that, under the test conditions, the inhibitor performs as a mixed type inhibitor. Linear Polarization Resistance measurements showed an increase in Rp values for inhibitor containing solutions as compared with the blank solution. The results revealed that the inhibitor efficiency increases with inhibitor concentration in the range from 12.5 ppm to 25 ppm. From the electrochemical results, it was found that the adsorption mechanism that better fits the present system follows the Langmuir isotherm model.