Corrosion inhibition of carbon steel by N,N′-Dimethylaminoethanol in simulated concrete pore solution contaminated with NaCl

Abstract

The inhibition behavior of N,N′-Dimethylaminoethanol (DMEA) as an organic corrosion inhibitor for carbon steel in simulated concrete pore solution contaminated with chloride ions encountered in the Mediterranean seawater (0.5 mol L−1), at different temperatures, was investigated by means of weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results obtained confirm that DMEA is an efficient corrosion inhibitor over the whole range of temperatures studied; it can significantly reduce the corrosion rate of carbon steel. The inhibition efficiency (IE%) increases as the DMEA concentration rises; it reaches its maximum average value of 80% at about 0.125 mol L−1. The corrosion inhibition of carbon steel by DMEA occurs through chemisorption of inhibitor molecules on the active sites, according to the Langmuir isotherm; this leads to the formation of a passive layer on the metal surface which separates the metal from direct contact with the corrosive medium and hence keeps the interface in a passive state. Furthermore, the activation parameters of corrosion processes were determined and discussed.