Effect of cation type on corrosion of steel treated by DNA corrosion inhibitor in simulated concrete pore solution

The purpose of this study is to evaluate the influence of cation types on the rust resistance performance of new nucleic acid corrosion inhibitors in simulated concrete pore solution. Four common chlorinated ice salts (sodium chloride (NaCl), potassium choride (KCl), calcium chloride (CaCl2) and magnesium chloride (MgCl2)) were selected to study the corrosion behaviour of chloride ions by linear polarisation resistance method, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy. The results show that the cationic type will affect the thickness of the passivated film on the steel surface and the compactness of the passivated film formed by iron oxide and nucleic acid rust inhibitor. The type of cations affects the critical chloride concentration of nucleic acid inhibitor, following Na+ approximate to K+ > Ca2+ > Mg2+.