Synergistic Effects between Gemini Inhibitor and Thiourea/thiazole/pyridine as Corrosion Inhibitors on N80 Steel in Brine Solution with Saturated CO2

Inhibition performances of gemini imidazoline inhibitor on N80 steel in a CO2-saturated brine solution have been researched using weight loss and electrochemical methods. The synergistic effects of gemini with other inhibitors have also carried out with chemical and electrochemical measurements. It is shown that the gemini inhibitor can inhibit corrosion effectively. Gemini inhibitor is anodic type. Gemini and other inhibitors exists apparent synergistic effect. The mixed inhibitors demonstrate excellent protection to N80 steel. The best formula of mixture inhibitors is presented, 10 mg/L gemini + 2 mg/L thiourea (TU) + 5 mg/L thiazole (TZ) + 5 mg/L pyridine (PD). The synergistic mechanism of gemini with other inhibitors is also proposed.