恒电位──恒电流瞬态响应技术研究钝化膜多层结构Ⅲ．氯化钠溶液中2205和316L不锈钢钝化膜稳定性的研究

采用恒电位－恒电流（Ｐ－Ｇ）瞬态响应技术研究了２２０５和３１６Ｌ不锈钢在０．５和１．０ｍｏｌ／ＬＮａＣｌ溶液中钝化膜的结构和稳定性．研究结果证实，体系的钝化膜均具有多层结构．讨论了氯离子在钝化膜生长和破坏过程中的作用．并提出可能的作用模式和破坏机制．由Ｐ－Ｇ响应曲线计算得到的各特征参数随极化电位的变化关系表明，２２０５双相钢在ＮａＣｌ介质中的耐蚀性明显高于３１６Ｌ不锈钢．另外，初步探讨了２２０５钢的组织结构与钝化膜稳定性的关系．

STUDY ON MULTIPLE-LAYER STRUCTURE OF PASSIVE FILM ON STAINLESS STEEL BY POTENTIOSTATIC-GALVANOSTATIC TRANSIENT TECHNIQUE III. Stability of Passive Film on 2205 and 316L Stainless Steels in NaCl Media

Structure and stability of the passive films on 2205 and 316L stainless steels in the NaCl solution media, 0.5 and 1.0 mol/L, were studied by using the potentiostatic-galvanostatic (P-G) transient technique. A multiple layer structure of the passive films is revealed on both steels. The action model and breakdown mechanism were suggested on the discussion of the Cl- behaviour against growth and breakdown of the passive films on the steels.The polarized potential dependence on the electrochemical parameters may be determined by P-G response curves. The corrosion resistance to NaCl media of 2205 diphase steel is much superior to that of 316L steel. Furthermore. A preliminary discussion of effect of metallographical structure of 2205 diphase steel on the stability and pitting resistance of passive film was made.