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采用XPS分析钢筋经模拟混凝土孔隙液浸泡后表面膜的化学组成,结合线性极化法和动电位扫描阳极极化曲线测试,研究钢筋在模拟混凝土孔隙液中表面膜化学组成与腐蚀电化学行为的关联.结果表明:钢筋在纯模拟液中处于钝化状态.在含Cl和不同pH值的模拟混凝土孔隙液中,随着Cl~-浓度的增加和pH值的降低,钢筋的腐蚀电位负移,电流密度增大;钢筋表面钝化膜Fe~(2+)的含量增加,Fe~(3+)的含量减少.当模拟液中外加Cl~-浓度达0.6mol/L或pH值降至11.31时,钢筋表面不发生钝化,但加入0.24mol/L NaNO_2缓蚀剂后又可使钢筋钝化从而抑制腐蚀.
XPS was used to analyze the chemical composition of the surface membrane after soaked in simulated concrete pore fluid. The linear polarization method and the anodic polarization curve of potentiodynamic scanning were used to study the chemical composition of the surface membrane and the electrochemical behavior of corrosion in the simulated concrete pore fluid The results show that the reinforcing steel is passivated in the pure simulated solution.In the simulated concrete with Cl and different pH, the corrosion potential of the reinforcing steel decreases with the increase of Cl ~ - and the decrease of pH value , The current density increased, the content of Fe ~ (2+) increased and the content of Fe ~ (3 +) decreased on the surface of passivation film.When the concentration of Cl ~ - was increased to 0.6mol / L or the pH was decreased to 11.31, the steel surface passivation does not occur, but after adding 0.24mol / L NaNO_2 inhibitor and then can passivation steel to inhibit corrosion.