钨酸根抑制不锈钢局部腐蚀的机理  

Study on the Inhibitive Mechanism of Localized Corrosion of Stainless Steel by TUngstate

作　　者：许淳淳[1] 吴小梅[1] 

机构地区：[1]北京化工大学材料科学与工程学院,北京100029

出　　处：《材料保护》2002年第1期1-4,共4页Materials Protection

基　　金：国家自然科学基金资助项目(No.59701009);国家重点基础研究发展规划项目(No.19990650)

摘　　要：用Ｘ射线光电子能谱（ＸＰＳ）研究了ＡＩＳＩ３０４不锈钢在含ＷＯ２－４＋Ｃｌ－的模拟闭塞电池中形成钝化膜的组成与结构及ＷＯ２－４抑制其局部腐蚀的机理。研究表明，闭塞区内ＡＩＳＩ３０４不锈钢表面的钝化膜的外层主要为ＷＯ２－４、ＣｒＯ３、ＣｒＣｌ３、ＦｅＣｌ２和ＦｅＣｌ３，此外，还有少量的Ｎｉ２Ｏ３、Ｆｅ２Ｏ３、ＣｒＯ２－４、γ－ＦｅＯＯＨ以及Ｆｅ（ＯＨ）３；溅射５　ｍｉｎ时膜内层主要为Ｃｒ２Ｏ３、ＣｒＯＯＨ、Ｃｒ（ＯＨ）３、ＦｅＣｌ２、ＦｅＣｌ３和ＷＯ３，还有少量的ＷＯ２和ＷＯ２－４。ＷＯ２－４对钝化膜的影响在于ＷＯ２－４迁入闭塞区后吸附在金属表面，可全部或部分取代吸附在钢表面的Ｃｌ－，并与腐蚀产物Ｆｅ２＋发生氧化还原反应生成Ｆｅ３＋和ＷＯ２，ＷＯ２－４与Ｆｅ２＋、Ｆｅ３＋反应生成难溶化合物ＦｅＷＯ４和Ｆｅ２（ＷＯ４）３覆盖在阳极上，形成较耐蚀的保护膜，降低闭塞区内自催化效应速度，从而抑制局部腐蚀的进一步发展。X-ray photoelectron spectroscopy (XPS) was used to study the com position and structure of passive film forming in the simulated occluded corrosion cell (OCC) of AISI304 stainless steel in NaCl solution containing tungstate, and the inhibitive mechanism of localized corrosion of stainless steel by tungstate. The results showed that outside passivating film was mainly composed of WO4 2-, CrO3, CrCl3, FeCl2 and FeCl3, as also a little Ni2O3, Fe2O3, CrO42-, γ-FeOO Hand Fe(OH)3. The inside film sputtered 5 minutes was composed of Cr2O3, C rOOH, Cr(OH)3, FeCl2, FeCl3 and WO3, in addition a little WO2 and WO42-. WO42- moving into OCC could replace the whole or part of Cl- adsorbing on metal surface, and react with Fe2+ to form Fe3+ and WO2, then produce indissoluble compounds Fe2(WO4)3 and FeWO4 to cover on the anodic area. The protective film could slow down the self-catalysis effect in the OCC, thus could prohibit the farther development of localized corrosion.

关 键 词：X射线光电子能谱 304不锈钢 钝化膜 钨酸根 局部腐蚀 防腐 

分 类 号：TG174.1[金属学及工艺—金属表面处理]