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采用动电位极化、电化学阻抗、动电位电化学阻抗谱和电容测量等方法研究了690合金在一回路模拟溶液中的电化学行为.极化曲线结果表明:690合金在两种溶液中都存在较窄的钝化区间,在0.5V出现二次钝化现象.电化学阻抗表明,690合金在不含Cl-溶液中的阻抗模值较大,而随Cl-的加入阻抗模值变小.动电位电化学阻抗谱表明,随扫描电位正移,钝化膜在两种溶液中具有相似的变化趋势,动电位电化学阻抗谱与动电位极化曲线完全对应.690合金在0.2V下形成的钝化膜的Mott-Schottky曲线测量表明,溶液中Cl-使得钝化膜中的施主和受主密度增大.
The electrochemical behavior of 690 alloy in the first-loop simulated solution was investigated by potentiodynamic polarization, electrochemical impedance, potentiodynamic impedance spectroscopy and capacitance measurement.The results of polarization curves showed that the 690 alloy was stable in both solutions There is a narrower passivation interval and a secondary passivation phenomenon occurs at 0.5 V. The electrochemical impedance shows that the resistance modulus of 690 alloy is larger in Cl- -containing solution and smaller with the addition of Cl- .Potentiometric electrochemical impedance spectroscopy showed that with the forward scan potential, the passivation film in the two solutions have a similar trend, the electrochemical impedance spectroscopy and the kinetic potential polarization curve completely corresponding to .690 alloy at 0.2V Mott-Schottky curve measurements of the formed passivation film showed that Cl- in the solution increased the donor and acceptor density in the passivation film.