ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Corrosion inhibition and surface analysis of amines on mild steel in chloride medium

Klodian Xhanari, Natalija Grah, Matjaž Finšgar, Regina Fuchs-Godec, and Uroš Maver

Faculty of Chemistry and Chemical Engineering, University of Maribor, Maribor, Slovenia

E-mail: matjaz.finsgar@um.si

Abstract: In this study, the corrosion inhibition effectiveness of eight amines, i.e. 2-ethylhexyl amine, aniline, benzylamine, butylamine, ethylamine, isopropylamine, octylamine, and triethanolamine, on C15 grade mild steel in 3 wt% NaCl solution is reported. The corrosion inhibition performance of the amines was studied using immersion tests at 25 and 70 °C, with and without the addition of KI as a possible intensifier. Among the inhibitors tested at 0.1 wt% concentration, the lowest corrosion rates were obtained for specimens immersed in solutions containing 2-ethylhexyl amine at 25 °C and triethanolamine at 70 °C. The highest inhibition effectiveness at 25 °C among all amines tested was obtained for 1.0 wt% butylamine with the addition of 0.5 wt% KI, while at 70 °C the lowest corrosion rate was obtained for specimens inhibited with 1.0 wt% isopropylamine. Surface analysis was subsequently performed on specimens inhibited by the most effective inhibitors. Adsorption of the selected amines on the C15 grade mild steel surface was confirmed by ATR-FTIR. 3D-profilometry showed a reduction in the surface roughness (less corroded) for the specimens inhibited with these inhibitors compared to the non-inhibited specimens. Contact angle measurements showed that all of the tested specimens were hydrophilic.

Keywords: Steel; Corrosion; Corrosion inhibitor; Amines; Surface analysis

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-016-0046-y

Chemical Papers 71 (1) 81–89 (2017)