Study on the corrosion inhibition performance of Schiff base corrosion inhibitor on Q235 steel

Abstract

Q235 steel is widely used in industry and daily life, and it is prone to corrosion during use, especially in hydrochloric acid solution where corrosion is particularly severe. Schiff base organic compounds can significantly inhibit the corrosion of Q235 steel in hydrochloric acid solution, making them a green and environmentally friendly organic compound. This article uses aniline, octadecylamine, and glutaraldehyde as raw materials to prepare two Schiff base corrosion inhibitors, namely bisaniline Schiff base and bisoctadecylamine Schiff base (named BXFJ and SXFJ respectively). The corrosion inhibition performance and mechanism of these two Schiff base inhibitors in Q235 steel in hydrochloric acid solution were studied using weight loss method, electrochemical testing, quantum chemical theory calculation, and molecular dynamics simulation. The results of weight loss method and electrochemical testing show that in a 1mol/L HCl solution, the corrosion inhibition performance of BXFJ at a concentration of 25mg/L is higher than that of SXFJ, indicating that BXFJ can exert excellent corrosion inhibition performance in HCl environment. Density functional theory (DFT) indicates that the active sites of the two Schiff bases are C=N double bonds, and molecular dynamics (MD) further confirms that both Schiff base corrosion inhibitors can adsorb on the surface of Q235 steel.