Study of inhibition mechanism of stearamide derivative on CO2 corroded steel X65

The mechanisms of the stearamide derivative inhibited CO2 corrosion on the mild steel X65 were studied in derivative containing aerated brine solution by electrochemical polarization measurements and electrochemical impedance spectroscopy (EIS) measurements. The electrochemical data showed that the corrosion resistance was greatly enhanced in the presence of stearamide derivative inhibitor. Polarization curves revealed that the inhibitor is an anodic type inhibitor, belonging to interface adsorbtion, and the inhibition is due to the negative catalytic mechanism. The maximum inhibition efficiency appeared at a concentration of inhibitor of 0.5 g/L. EIS has two time constants and the equivalent circuit was suggested as R(C(R(CR))).