Corrosion inhibition of carbon steel by cerium citrate compound in NaCl medium

The efficiency of cerium chloride, cerium nitrate and cerium citrate was investigated for corrosion inhibition of carbon steel in 3.5% NaCl solution by potentiodynamic polarization, electrochemical impedance spectroscopy and surface analyses (XPS and SEM). The measurements demonstrated that these cerium salts all displayed strong cathodic behavioura for carbon steel in 3.5% NaCl solution, and the corrosion rate decreased with the addition of the cerium salts with a maximum decrease and critical value effect offered by cerium citrate. Scanning electron microscopy and X-ray photoelectron spectroscopy confirmed the formation of precipitates of cerium citrate on carbon steel, which contained cerium, iron, oxygen and carbon.