Corrosion Resistance of API X52 Carbon Steel in Soil Environment

The aim of this work is to evaluate the corrosion resistance of the API SL X52 steel in soil from the Serra do Ouro Branco, Minas Gerais, Brazil. The electrolytes studied were an aqueous extract of the soil and a synthetic solution of the soil medium. The electrochemical techniques used were Tafel analysis and electrochemical impedance spectroscopy. The semi-quantitative chemical analysis of the soil was performed using X-ray fluorescence spectroscopy. The steel samples, after Tafel analysis, were analyzed using the scanning electron microscopy coupled with the energy dispersive spectrometry. The API steel showed a higher corrosion potential and polarization resistance and a lower current density in aqueous extract of soil. The Nyquist diagrams show two capacitive arcs, with two time constants.