New corrosion inhibitor for 13Cr stainless steel in 20% HCl solution

Purpose A novel compound was synthesized by cyclohexylamine, acetophenone and cinnamaldehyde through Mannich reaction in laboratory to use as corrosion inhibitor for steel in acidification process. Design/methodology/approach The corrosion and inhibition of 13Cr stainless steel in conventional acidification solution were investigated by electrochemical measurements and soaking experiments. The corrosion appearance was observed with scanning electron microscope on the whole surface of 13Cr stainless steel in 20% HCl solution, and the protection film was confirmed on the surface in presence with inhibitor. Findings Results manifested that the inhibitor C23H27NO can effectively inhibit the corrosion reaction by forming an adsorption layer function as a barrier. Polarization curves indicated that the mixed inhibitor can reduce anodic dissolution and cathodic hydrogen evolution reactions simultaneously. The results of impedance measurements indicated that this inhibitor cannot change the corrosion mechanism of 13Cr stainless steel in 20% HCl solution. The results of the study can provide a theoretical basis for the application of 13Cr stainless steel in conventional acidification solutions during oil well acidification construction process. Originality/value A novel compound was synthesized by cyclohexylamine, acetophenone and cinnamaldehyde through Mannich reaction in laboratory to use as corrosion inhibitor for steel in acidification process. The corrosion and anti-corrosion mechanism of 13Cr steel in acid solution was proposed.