Study on Corrosion Inhibition Performance and Mechanism of Quinoline Quaternary Ammonium Salt and L-Methionine on Pre-Corrosion Q235 Steel

The corrosion inhibition properties and mechanisms of quinoline quaternary ammonium salt (QA) and L-methionine (LM) on pre-corroded Q235 carbon steel in 1wt% HCl solution were studied using the weight loss method and molecular simulation technology. The degree of pre-corrosion of steel will affect the corrosion inhibition performance of the corrosion inhibitor. QA and LM compete to adsorb to the iron surface to form a film, and the repulsion between the corrosion product and the film reduces the slow-release performance. Graphical Abstract The molecular configuration and front-line orbital distribution of QA and LM were optimized at the B3LYP/6-311++G(d,p) level, the quantum chemical parameters of QA and LM were calculated, and the adsorption behavior of QA and LM on the surface of partially oxidized Fe(110) and the surface of fully oxidized Fe(110) was studied