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一、前言氯离子是导致奥氏体不锈钢发生应力腐蚀破裂和孔蚀的特性离子。它从主体溶液迁入闭塞区已被许多作者的实验所证实。我们以前的工作证明Cl~-的迁入量与通过闭塞区的电量成直线关系,Cl~-增浓是促进闭塞区合金溶解的因素之一。I~-和Cl~-同属卤族离子,但据报道将I~-加入含Cl~-的体系对奥氏体不锈钢的应力腐蚀破裂具有抑制作用。显然探明特性离子(如Cl~-、I~-等)的作用有益于认识局部腐蚀的机理。本工作研究I~-的迁移规律以及对闭塞电池腐蚀的影响。二、实验方法 1.闭塞电池不同阶段的溶液成份测定——模拟闭塞电池实验采用文献[3]所用的方法,测量0.5mol/L NaCl溶液中加入0～0.3mol/L NaI后304不锈钢模拟裂缝不同阶段的溶液成份,进而了解I~-对缝内化学和电化学状态的影响。在“闭塞电
I. INTRODUCTION Chloride ion is a characteristic ion that causes stress corrosion cracking and pitting in austenitic stainless steel. Its migration from the bulk solution into occluded areas has been demonstrated by many authors’ experiments. Our previous work proves that the immigration amount of Cl ~ - is in a linear relationship with the electricity passing through the occluded area. Cl ~ - enrichment is one of the factors that promote the dissolution of the alloy in the occluded area. I ~ - and Cl ~ - belong to the same halogen ions, but it has been reported that adding I ~ - into the system containing Cl ~ - inhibits the stress corrosion cracking of austenitic stainless steel. It is obvious that the function of identifying specific ions (such as Cl ~ -, I ~ - etc.) is beneficial to understand the mechanism of local corrosion. This work is to study the I ~ - migration rules and the impact on the battery cell corrosion. Second, the experimental methods 1. Determination of the different phases of the occlusive battery solution composition - simulated occlusion cell experiments using the method used in reference [3], measuring 0.5mol / L NaCl solution after adding 0 ~ 0.3mol / L NaI 304 stainless steel simulated cracks Different stages of the solution composition, and then to understand the I ~ - on the seam chemical and electrochemical state. In the "blocking electricity