Investigation of three betaine surfactants and KI compounds as a corrosion inhibitor on carbon steel in industrial pickling

Corrosion of metals has significant implications for international livelihoods, and excessive pickling can lead to corrosion of Q235 steel during the production process, thus, this study investigates the corrosion inhibition performance of three betaine surfactants (SB3-n, 10, 12, 14) with different carbon chain lengths and KI compounds, on Q235 steel in 1 mol·L -1 hydrochloric acid through experimental and theoretical analyses. The results show that the optimal efficiency of SB3-n/KI can be above 90%. Corrosion inhibitors adsorb simultaneously on the metal surface, making the metal surface smooth and flat. Theoretical analysis shows that the adsorption ability of I - is higher than that of Cl - , and all three compound inhibitors adsorb on the metal surface chemically, with the adsorption energy in the order of SB3-14