INHIBITING AND ACCELERATING EFFECTS OF AMINOPHENOLS ON THE CORROSION AND PERMEATION OF HYDROGEN THROUGH MILD-STEEL IN ACIDIC SOLUTIONS

The influence of aminophenols on the corrosion and hydrogen permeation of mild steel in 1 M HCl and 0.5 M H2SO4 has been studied using weigh t loss and gasometric measurements and various electrochemical techniq ues. All the isomers of aminophenol inhibit the corrosion of mild stee l in 1 M HCl and accelerate it in 0.5 M H2SO4. They behave predominant ly as cathodic inhibitors. Aminophenols, except PAP in 1 M HCl, enhanc e the permeation current in both the acids. The adsorption of PAP on t he mild steel surface in 1 M HCl obeys the Langmuir adsorption isother m. Surface analysis and ultraviolet spectral studies are also carried out to establish the mechanism of corrosion inhibition and acceleratio n of mild steel in acidic solutions.