Electrochemical Noise Application for Carbon Steel Corrosion Rate analysis at Carbon Dioxide Gas Saturated Solution

摘要

The high CO_2 content at pre-salt oil field production in Brazil have generated some concern about real corrosion rate evaluation for corrosion monitoring and material selection. Some produced oils have presented CO_2 level higher than 30%. This work intended to get a better accuracy corrosion rate at carbon steel pipeline material in sodium bicarbonate/CO_2 solution at flowing systems. The applied techniques were linear polarization resistance, Tafel's extrapolation method and electrochemical noise. The obtained corrosion rate and polarization resistance follow the dissolution precipitation corrosion mechanism for the carbon steel at deaerated 0.5 m/l sodium bicarbonate solution saturated with CO_2. The Linear Polarization Resistances and corrosion rates obtained from Tafel extrapolation results were compared with the noise resistance indicating good correlations.