关键词: 局部腐蚀, 换向电位, 闭塞电池, 保护电位

Abstract: 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.