Electrochemical behavior of API X70 steel in hydrogen sulfide-containing solutions

As an attempt to contribute to the understanding of the corrosion process of steel by hydrogen sulfide (H2S), the corrosion behavior of an X70 pipeline steel immersed in several H2S-containing solutions is analyzed in this work. Linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) techniques were used in order to characterize the corrosion behavior of X70 steel in H2S-containing solutions. Electrochemical parameters such as charge-transfer resistance, R-ct, polarization resistance, R-p, and corrosion rate are presented in this work. Additionally, a comparison between static and turbulent flow conditions was made in order to describe the corrosion behavior of X70 steel. Turbulent flow conditions were controlled using the rotating cylinder electrode (RCE) (at 1,000 rpm) in a saturated H2S solution.