大气中SO_2对金属银的电化学腐蚀行为  

Electrochemical Behavior of SO_2 Corrosion of Silver Electrode in Air Environment

作　　者：国瑞峰[1,2] 葛红花[2] 尹然[3] 蔡兰坤[4] 周浩[5] 

机构地区：[1]上海大学化工系,上海200444 [2]上海电力学院上海高校电力腐蚀控制与应用电化学重点实验室,上海200090 [3]上海大学环境系,上海200444 [4]华东理工大学,上海200237 [5]上海博物馆文物保护与考古科学实验室,上海200233

出　　处：《腐蚀与防护》2009年第11期761-764,共4页Corrosion & Protection

基　　金：科技部国家科技支撑计划项目资助(编号2006BAK20B01)

摘　　要：利用三电极电化学电池研究了大气环境中的SO2对金属银的腐蚀行为。通过电化学阻抗谱和极化曲线分析了金属银在不同厚度液膜、不同湿度、不同SO2气体浓度及不同暴露时间下的初期腐蚀行为。结果显示:电极表面液膜越薄,金属银的腐蚀电流密度越大;采用镜头纸控制银电极表面液膜厚度,随着大气环境湿度的增加,银的腐蚀速度减小;在自然大气环境中,随着大气中SO2浓度的增加,暴露时间的延长,银电极的阻抗值增大,这可能是由于银电极表面Ag2O、AgOH和亚硫酸银等反应产物膜的形成的原因。Electrochemical cell was used to measure the SO2 corrosion of silver under a thin electrolyte layer. The effects of thickness of electrolyte layer, relative humility （%RH）, SO2 concentrations and exposure time on the earlier corrosion behavior of silver were investigated by electrochemical impedance spectroscopy （EIS） and polarization. The results showed that the corrosion rate increased while the thickness of electrolyte layer decreased. The relative humidity controlled the reaction process by controlling the thickness of the electrolyte layer on the silver electrode. The electrochemical resistance became higher with increasing SO2 concentration. With the increase of exposure time, the surface resistance increased due to the formation of reaction product film of Ag2O and AgOH.

关 键 词：SO2 银 大气腐蚀 

分 类 号：TG172.3[金属学及工艺—金属表面处理] TG174.36[金属学及工艺—金属学]