摘要
利用电化学阻抗谱(EIS)研究X100管线钢在水饱和酸性土壤中短期的电化学腐蚀行为。结果表明,X100管线钢在鹰潭水饱和土壤中浸泡104 h后已产生点蚀。腐蚀过程的EIS谱具有两个时间常数特征,高频区为代表反应的容抗弧,低频区为代表吸附或点蚀形核期产生的感抗弧。腐蚀初期(1 h～33 h),由于水饱和土壤介质电导率较低,电极反应过程受扩散控制;腐蚀产物在电极表面积累对反应离子扩散有阻碍作用,使阻抗增大;腐蚀产物膜疏松多孔,形成局部活化区域,使阻抗减小;Cl^-对腐蚀产物膜有破坏作用且在膜内局部地区浓缩,诱发点蚀,使阻抗减小,出现感抗特征。
The electrochemical impedance spectroscopy（EIS） of X100 steel in water-saturated acidic soil was studied.The results show that pitting corrosion occured after soak in Yingtan saturated soil water for 104 hours,and the Nyquist diagram had two time constants,a capacitive loop at high frequency represented the reaction,and an inductive loop at the low frequency for representing adsorption or the pitting nucleation period of the inductance.Diffusion control results in the increasing of impedance because of low media conductivity during the initial corrosion period.The accumulation of corrosion products on the electrode surface hinders proliferation of reactive ions which also can result in impedance increasing with the test time.The corrosion scale is porous and forms activated regions which result in the decrease of impedance.Concentration of harmful Cl^- in the corrosion products initiates localized pitting and brings reactance.
出处
《中国腐蚀与防护学报》
CAS
CSCD
北大核心
2011年第5期377-380,共4页
Journal of Chinese Society For Corrosion and Protection
基金
国家科技部基础条件平台建设项目(2005DKA10400)
科技部科技支撑计划项目(2006BAK0201)资助
