Investigation of adsorption and inhibitive effect of acid red GRE (183) dye on the corrosion of carbon steel in hydrochloric acid media

The adsorption and corrosion inhibitive effect of acid red GRE (183) dye on carbon steel alloy in 1 M HCl solutions was studied using various techniques. Results of weight loss, Tafel polarization measurements and electrochemical impedance spectroscopy (EIS) techniques show that this compound has fairly good inhibiting properties for steel corrosion in acidic bath; with efficiency around 96% at a concentration of 50 ppm. The inhibition is of a mixed anodic–cathodic nature. Factors affecting the corrosion process have been calculated and discussed. Acid red GRE (183) dye was shown to be an inhibitor in the acidic corrosion. Inhibition efficiency increased with acid red GRE (183) dye concentration but decreased with rise in temperature, corrosion inhibition is attributed to the adsorption of acid red GRE (183) dye on the carbon steel surface via a physical adsorption mechanism. Langmuir isotherm is found to provide an accurate description of the adsorption behavior of the investigated azo compound. The nature of the protective film was investigated using SEM and EDX techniques.