The corrosion inhibition performances of octadecylamine (OCT) and tetradecyl trimethyl ammonium bromide (TTAB) for carbon steels in H2S and CO2 brine solution were investigated by weight loss, potentiodynamic polarization, molecular dynamic simulation and XPS ****ysis. TTAB showed better inhibition effects on H2S and CO2 induced corrosion than OCT. Synergistic corrosion inhibition effect was found between OCT and TTAB with proper mass ratios and the best inhibition performance was achieved with 10 mg L−1 OCT and 20 mg L−1TTAB. The synergi** was correlative to the fractional free volume of the inhibitor film of OCT and TTAB.
