Corrosion inhibition efficiency of compound nitrite with D-sodium gluconate on carbon steel in simulated concrete pore solution

•The inhibitory performance and mechanism of compound nitrite with D-sodium gluconate (D-sg) on carbon steel in simulated concrete pore solution was studied.•The ratio of Fe3+/Fe2+ increases as the concentrate of the corrosion inhibition increased.•The molecular dynamics model intuitively shows that the corrosion inhibitor competes with chloride ions for adsorption on the surface of carbon steel. The inhibitory performance and mechanism of compound nitrite with D-sodium gluconate on carbon steel in simulated concrete pore solution was studied. Results of EIS, SEM and AFM indicate that the pitting corrosion of the steel was effective hindered by corrosion inhibitor in the pore solution. XPS results shows that the stability of the passive film on carbon steel was enhanced by corrosion inhibitor, which explained the adsorption and inhibition behavior of composite nitrite. Molecular dynamics simulation results show that D-sg competed with chloride ions for adsorption and effectively weakened the adsorption of chloride ions on the surface of carbon steel.