AbstractA novel triazine derivative, 2, 4‐diamino‐6‐dodecamido‐1, 3, 5‐triazine (DT), is synthesized by the dehydration condensation of melamine and lauric acid, and its inhibitive performances for the corrosion of Q235 carbon steel in 1 mol/L HCl solution is investigated by electrochemical polarization, electrochemical impedance spectroscopy, scanning electron microscopy, and atomic force microscope. The results reveal that its best inhibition efficiency reaches 96.98% at a concentration of 2.5 g/L. The calculation results of kinetic and thermodynamic parameters indicate that the adsorption of DT on carbon steel surface obeys Langmuir adsorption isotherm with both physical and chemical adsorption. It is demonstrated that long‐chain amide (>8C) substituted 1, 3, 5‐triazine derivative has the synergistic corrosion inhibition effect of the surface fixation on metal iron and the hydrophobic adsorption layer.