三价铬钝化膜为什么会产生六价铬  

Reasons for the production of hexavalent chromium in trivalent passivation coating

作　　者：蒋雄[1] 

机构地区：[1]华南师范大学化学与环境学院,广东广州510006

出　　处：《电镀与涂饰》2008年第12期23-24,共2页Electroplating & Finishing

摘　　要：根据三价铬和六价铬的氧化还原性质,指出在碱性介质中三价铬可以被氧气氧化成六价铬,认为三价铬钝化膜中三价铬的存在形式(某种三价铬的碱式盐)是其在空气中放置时三价铬被氧化为六价铬的内在原因。提出了采用无铬钝化工艺,钝化后封闭及加强三价铬钝化工艺管理和钝化产品的存放管理等应对措施。Based on the redox properties of trivalent and hexavalent chromium, it is pointed out that, in basic media, trivalent chromium can be oxidized to hexavalent form by oxygen and the trivalent chromium existing in trivalent chromium passivation coating, generally accepted as being in the form of a basic chromium（Ⅲ） salt, is considered as the internal cause for the oxidation of trivalent chromium to hexavalent chromium during the placement of trivalent chromium passivation coating in air. Some countermeasures were presented, such as using non-chromium passivation processes, sealing after passivation, and strengthening the management of trivalent chromium passivation process and the storage of passivated products.

关 键 词：三价铬钝化 六价铬 产生原因 对策 

分 类 号：TG178[金属学及工艺—金属表面处理] TQ153.15[金属学及工艺—金属学]