Effect of calcium lignosulfonate on rust resistance of carbon steel in simulated concrete pore solution
Reinforced concrete structures are often damaged due to corrosion of steel bars.Adding inhibitors can effectively inhibit corrosion of steel bars and improve the durability of reinforced concrete structures.Here,the calcium lignosulfonate was added to the simulated concrete pore solution to study its inhibition effect and mechanism on carbon steel by open circuit potential,AC impedance spectroscopy and potentiodynamic polarization curves.The results showed that in the corrosive solution of 3.5%NaCl and pH12.5,the calcium lignosulfonate retarded the corrosion via increasing the open circuit potential,increaing the charge transfer resistance and reducing the corrosion current density.Besides,the calcium lignosulfonate molecular can compete with chloride ions for adsorption on the surface of carbon steel,and protect the passive film and inhibit the development of corrosion.