Cerium salt as green corrosion inhibitor for steel in acid medium

The inhibition performance of cerium sulphate tetrahydrate on the corrosion of steel in 1.0 M HCl solutions was investigated by using chemical (weight loss), electrochemical (electrochemical frequency modulation, electrochemical impedance spectroscopy, potentiodynamic polarization) and atomic force microscopy (AFM) at 25 ± 1 °C. Cerium sulphate tetrahydrate gave sufficient inhibition for the steel surface in molar hydrochloric acid solutions. AFM measurements show that the steel surface roughness was 123.08 nm before immersion, increased to 764.24 nm after immersion in uninhibited solution, and became 122.62 nm in the presence of the salt owing to the protective formation of an inhibitor layer.