Inhibition of the corrosion of X70 and Q235 steel in CO2-saturated brine by imidazoline-based inhibitor

The imidazoline-based inhibitor had an excellent inhibition effect on X70 and Q235 steels at the concentration of 4.8780 × 10− 5 mol/l inhibitor. In this case, the inhibition efficiencies for X70 and Q235 were 97.31% and 97.44%, respectively. When the two steels samples were simultaneously immersed in the solution with inhibitor at low concentration (4.8780 × 10− 6 mol/l), the inhibition efficiencies for X70 and Q235 were 8.35% and 95.10%, respectively, indicating that most of the inhibitor molecules adsorbed onto Q235 steel surface.112