Abstract
Application of organic compounds as corrosion inhibitors, particularly heterocyclic compounds, is one of the most economical and effective corrosion mitigation methods of steel alloys. These compounds become effective by forming a corrosion inhibitive hydrophobic film over the metallic surface. The corrosion inhibition potential of these compounds depends on numerous factors, including substituents present in their molecular structures. Literature investigation suggests that these compounds become effective by blocking the active sites (responsible for the corrosion) through their adsorption using their electron-rich polar functional groups and multiple bonds. Adsorption of these compounds on the metallic surface mostly follows the Langmuir adsorption isotherm model. Generally, these compounds act as mixed- and interface-type corrosion inhibitors as they retard both anodic and cathodic Tafel reactions and increase the value of charge transfer resistance, respectively. The present review article features the collection of reports on the inhibition of steel corrosion using different families of organic compounds. Other aspects of corrosion, such as the form of corrosion and its mitigation using experimental and computational methods, have also been discussed. (C) 2021 Elsevier B.V. All rights reserved.