Yan-Feng Zhu

Study on a Titanate Film and its Photocathodic Protection Effect for 403 Stainless Steel

Conference Name:Coatings for Corrosion Protection - 220th ECS Meeting. Conference Address: Boston, MA, United states. Time:October 9, 2011 - October 14, 2011.

Study on the corrosion behavior of reinforcing steel by electrochemical techniques and XPS

Conference Name:Corrosion General Poster Session - 220th ECS Meeting. Conference Address: Boston, MA, United states. Time:October 9, 2011 - October 14, 2011.

EFFECT OF NO 2 - AND Cl - ON THE CORROSION BEHAVIOR OF REINFORCING STEEL IN SIMULATED CONCRETE PORE SOLUTIONS: EFFECT OF NO 2 - AND Cl - ON THE CORROSION BEHAVIOR OF REINFORCING STEEL IN SIMULATED CONCRETE PORE SOLUTIONS

应用极化曲线法和电化学阻抗技术研究了NO2^-和Cl^-对钢筋在不同pH值的模拟混凝土孔隙液中的腐蚀行为,结果表明,钢筋耐蚀性与溶液的pH值,以及NO2^-和Cl^-的浓度相关,pH值的降低和Cl^-浓度的增高都会使钢筋的耐蚀性降低。在含Cl^-的模拟液中,随着NO2^-浓度升高,钢筋腐蚀速率降低,在pH值为12.50和10.50的溶液中,当[NO2^-]/[Cl^-]≥0.4时,NO2^-对钢筋具有良好的阻锈作用。Under normal conditions, reinforcing steel in concrete maintains its passivity because of the high alkalinity of the concrete pore solution. However, steel passivity may be broken and the steel corrosion takes place due to concrete carbonation and/or chloride ingress. In fact, premature failure of reinforced concrete structures due to the steel corrosion has been a major problem in civil engineering. Therefore, the study of corrosion and protection of reinforcing steel is of indispensable importance to prolonging the service life of reinforced concrete structures. The application of inhibitors is an effective and economical method to prevent the corrosion of reinforcing steel. NaNO2 is a notable corrosion inhibitor which is effective in the steel corrosion control by reacting with ferrous ions to form a protective ferric oxide film on the steel surface, but unfortunately it can also accelerate the steel corrosion when the amount of nitrite is insufficient in amedium. In the present work, the linear polarization and electrochemical impedance spectroscopy were used to study the effect of nitrite and chloride ions on the corrosion behavior of reinforcing steel in simulated concrete pore solutions with different pH values. The results showed that the corrosion resistance of reinforcing steel is related with the pH value of the solution, nitrite ion concentrations and chloride ion concentrations. The drop of pH value and the increase of chloride ion concentration would result in the decline of corrosion resistance of reinforcing steel in the solution. The corrosion rate of reinforcing steel decreased with the NO 2 concentration increasing in the simulated concrete pore solutions with Cl , and the NO 2 ions had a good inhibiting effect on the steel when the concentration ratio of NO 2 and Cl was 0.4 or higher for the solutions of pH=12.50 or pH=10.50.