Synergistic inhibition of X80 steel corrosion by combination of cerium nitrate and sodium molybdate

The corrosion inhibition effects of sodium molybdate, cerium nitrate and Mo-Ce(III) composite corrosion inhibitor on X80 pipeline steel in hydrochloric acid solution were investigated by chemical and electrochemical methods. The apparent activation energy (Ea), enthalpy (ΔHa) and entropy (ΔSa) of dissolution reaction of X80 pipeline steel in hydrochloric acid solution without and with different inhibitors were calculated according to the parameters obtained by polarization curves. The implementation possibility and reality of the corrosion inhibition reaction were proved. And the results showed that Mo-Ce composite corrosion inhibitor makes the steel specimen surface to form a more orderly dense layer, and then increases the ther-mo dynamic parameters of dissolution reaction of X80 pipeline steel, decreases the corrosion rate. Through the comparative experiments, it was found that cerium nitrate with sodium molybdate produced strong synergistic effect on corrosion inhibition for X80 pipeline steel. ©, 2015, Editorial Office of Chinese Rare Earths. All right reserved.