Corrosion Inhibition of X70 Steel by Butyl Quaternary Ammonium Halides Compounds in Sodium Chloride Solution

This study investigates corrosion inhibition of X70 steel surfaces, by Butyl-QuaternaryAmmonium halides, in a 3% of NaCl solution with pH = 6. In the first part, the influence of inhibitor concentration study reveals that the I-TBA is the best inhibitor (≈79% on the X70 steel). Each compounds exhibits Langmuirian behaviour and the values of ΔG° indicate that we have a physical adsorption. In the second part, the influence of immersion time study on the stability of the formed films reveals that they are stable and require about 150 min to be established, and deliver efficiencies that overtake the 70% in all cases. The stationary polarization curves and electrochemical impedance spectroscopy (EIS) diagrams show the high inhibitory effect of iodide compared with other halides.