Electrochemical Behavior of Carbon Steel in Neutral Chloride Solution Adding Amine-Carboxylate Based Corrosion Inhibitor

Studies have been carried out to investigate the inhibiting effect of organic corrosion inhibitor (OCI) on steel electrode in 1% NaCl solution using electrochemical techniques. The test results show that the commonly used inhibitors such as triethanolamine (TEA), dimethylethanolamine (AMA) and monofluorophosphate (MFP) as well as their complexes are efficient when used in the chloride solution, while an amine-carboxylate inhibitor (C12) prepared in lab bring an excellent inhibitive performance when added in the chloride solution. Based on the date of linear polarization resistance, the calculated lowest corrosion current of the steel electrode for 10d is about 0.32% of the initial current of the electrode in the chloride solution before adding C12 inhibitor.The date of potentiodynamic scanning curves also show that the inhibitor has self-repair ability even when the steel is localized corrosion attack. The Bode-phase diagram results suggest that the protective layer at the surface of steel becomes homogeneous and compact in the presence of chloride.