Electrochemical behavior and mechanism of CO₂ corrosion on P110 steel in simulated oilfield solution

Abstract

Purpose

This paper aims to further investigate the behavior and mechanism in simulated oilfield solution on CO₂ corrosion of P110 steel at various temperatures by potentiodynamic sweep and electrochemical impedance spectroscopy (EIS) measurements, especially discussing the influence of the coverage fraction of corrosion film.

Design/methodology/approach

Potentiodynamic sweep and EIS measurements were applied to investigate the behavior and mechanism with the effect of temperature on CO₂ corrosion of P110 steel in simulated oilfield solution at 30°C, 60°C and 90°C.

Findings

The corrosion parameters of polarization curves, such as corrosion potential (Ecorr), corrosion current density (icorr), anodic and cathodic branches slopes (βa and βc), were analyzed and discussed in detail. In addition, the equivalent circuit models and ZsimpWin software were utilized to fit and analyze the Nyquist plots. The plots showed that corrosion potential shifted more negatively as temperature increased. The corrosion current density (icorr) initially increased and then decreased with the increase of temperature. The impedance spectra measured at various temperatures had different time constants.

Originality/value

The paper highlights that the coverage fraction θ of corrosion film is one most important and key variable influencing CO₂ corrosion mechanisms.

Citation

Yin, Z.F., Wang, X.Z., Gao, R.M., Zhang, S.J. and Bai, Z.Q. (2011), "Electrochemical behavior and mechanism of CO₂ corrosion on P110 steel in simulated oilfield solution", Anti-Corrosion Methods and Materials, Vol. 58 No. 5, pp. 227-233. https://doi.org/10.1108/00035591111167686