Corrosion Inhibition of Copper-Iron Alloy in Acid Solution Using Cetylpyridinium Bromide as Cationic Surfactant

Resumo

The corrosion and corrosion inhibition of Cu–Fe (20%) alloy are studied in 0.5 M H₂SO₄. Copper and iron samples are compared to the Cu–Fe alloy to understand the behavior of the Cu–Fe alloy in the corroding medium. Different techniques such as open circuit potential measurement, Tafel plots and electrochemical impedance spectroscopy (EIS) are used in this study. Dissolution of iron is found to be a controlling step in the corrosion behavior of the Cu-Fe alloy. Scanning electron microscope (SEM) and electron diffraction X-ray spectroscopy (EDX) charts confirm the above conclusion. The aggregation transition concentration (ATC) is determined and its value helps to interpret the CPBr inhibition behavior. Langmuir Adsorption isotherm is found to fit with the experimental data and relatively high negative value of the free energy of adsorption suggests strong adsorbability of the CPBr on the alloy surface.