复杂钝化体系P－G响应特征的研究

POTENTIOSTATIC-GALVANOSTATIC TRANSIENT RESPONSE CHARACTER OF COMPLEX PASSIVE SYSTEMS

采用恒电位－恒电流（Ｐ—Ｇ）瞬志响应技术研究了多层结构钝化膜和存在吸附层钝化膜的复杂钝化体系提出了判断钝化膜多层结构的方法以及表征钝化膜不同层稳定性的特征参数，并建立了描述复杂钝化体系Ｐ—Ｇ响应特征的数学模型．研究了２２０５和３１６Ｌ不锈钢在２．５ｍｏｌ／ＬＨ２ＳＯ４中钝化膜的结构，以及吸附型缓蚀剂哌啶和癸胺对３０４不锈钢在０．５ｍｏｌ／ＬＮａＣｌ介质中孔蚀的抑制作用研究结果证实所建立的模型能很好地反映研究体系的Ｐ—Ｇ响应特征．利用提出的特征参数随极化电位和极化时间的变化关系，有效地分析了钝化膜的生长规律和稳定性。

The complex passive systems,such as the multiple-layer structure passive films and the passive films with adsorption of inhibitors have been studied by the potentiostatic-galvanostatic (P-G) transient technique. The way which determines whether there exsists the multiple-layer structure on passive films or not and the characteristic parameter which can be used to describe the stability of the layers are put forward, further, a mathematical model has been set up for the P-G response curves of the complex systems mentioned above. The film structure of 2205 SS and 316L SS formed in 2.5mol /L H2SO4 and the effect of the adsorption inhibitors, piperidine and n-decylamine,on the pitting of 304 SS in 0.5 mol/L NaCl have also been studied.The results prove that the new model can illustrate well the P-G response characteristics of the complex passive system.On the basis of the relation between the parameters and the polarized potential and time,the stability and growth laws of passive films and the inhibition effect on the different stages of pitting may be well analysed.