孔蚀阴极保护电位测试方法的研究

A Study on the Cathode Protection Potential Against Pitting Corrosion

采用模拟闭塞电池法和模拟闭塞区溶液法测定了０Ｃｒ１８Ｎｉ９奥氏不锈钢０．５ｍｏｌ·Ｌ－１ＮａＣｌ溶液体系在孔蚀的不同阶段孔内外间电流的换向电位ＥＴ．结果表明，在一定的范围内，ＥＴ值随闭塞区溶液组成的变化而变化．将ＥＴ与由孔蚀滞后环法于不同扫描速度和不同回扫电流所测得的孔蚀保护电位ＥＰ值作比较，发现ＥＰ值范围处于ＥＴ值范围之内。

The methods have been developed to determine the protection potential against pitting corrosion. They are based on the theory that the pitting protection potential(Ep) is actually the transition potential of the direction of current between the occluded cell and the external surface (ET).ET lasts from -220 mV to -440 mV(SCE), the lowest of which can be considered as cathode protection potential. The Ep values determined with cyclic potentiodynamic polarization method is included in the ET with above methods.