应用恒电位法测定锌合金阳极在不同pH值的Ca(OH)2溶液中的极化曲线,X-射线衍射分析了该锌合金阳极的腐蚀产物.实验表明:在不同pH值的碱性溶液中锌合金阳极表现出完全不同的电化学行为:在不稳定钝化区内出现了3个零电流电位;根据锌合金阳极在Ca(OH)2溶液中极化曲线测定了活化区内各不同pH值下的零电流电位、腐蚀电流密度,以及钝化区间内的维钝电流密度、钝化膜破裂电位等电化学参数;绘制电位-pH图,并与纯锌-水系的电位-pH图进行比较.
The polarization curves of zinc alloy anodes in Ca(OH)2 solutions have been measured by potentiodynamic method,and the composition of corrosion products were examined by X-ray-diffraction(XRD).The experimental results indicated that not only the electrochemical behavior of zinc alloy anodes were absolutely different in every alkaline solutions,but also many electrochemical parameters were determined,such as zero current potential(E0),the density of corrosion current(icorr),passive current density(ip),breakdown potential(Eb),and so on.There were three zero current potential when zinc alloy anodes in some Ca(OH)2 solutions which made passive state unstable.The graphs of E-pH about zinc alloy anodes dipped in different Ca(OH)2 solutions were drawn,and compared with the potential-pH chart for Zn-H2O system.
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