流动腐蚀介质中双相不锈钢的电化学阻抗谱  

EIS OF DUPLEX STAINLESS STEEL IN FLOWING CORROSIVE MEDIA

作　　者：雍兴跃[1] 刘景军[1] 林玉珍[1] 

机构地区：[1]北京化工大学材料科学与工程学院

出　　处：《化工学报》2003年第12期1713-1718,共6页CIESC Journal

基　　金：国家自然科学基金资助项目 (No 5 0 10 10 0 2 )~~

摘　　要：测定了流动氯化物体系中双相不锈钢电极的电化学阻抗谱 ,发现在单相流中 ,当流速低于临界值时 ,阻抗谱为直径较大的容抗弧 ;一旦流速超过临界值 ,阻抗谱特征为 2个容抗弧 .流动介质中加入固体颗粒之后 ,阻抗谱在低流速下高频区为容抗弧 ,低频区为直线段 ,而高流速下低频区则出现实部收缩现象 .根据腐蚀电化学理论 ,提出了流动体系中双相不锈钢电极反应过程动力学模型 ,较好地解释了流动体系中双相不锈钢电极的电化学阻抗谱 。The electrochemical impedance spectroscopy(EIS)of duplex stainless steel in flowing chloride solution was measured. It was found that EIS of duplex stainless steel in flowing single phase media is a capacitive loop with a larger diameter when flow velocity is below the critical value, but EIS of duplex stainless steel is composed of two capacitive loops once flow velocity is above the critical value. If corrosive media contains solid particles, EIS of duplex stainless steel consists of a capacitive loop in high frequency range and a straight line in low frequency range when flow velocity is lower than critical value. However, an inductive component was observed on impedance plane and the shrinkage of the real part of impedance was also seen in low frequency range though EIS of duplex stainless steel is only a capacitive loop when flow velocity is higher than critical value. Electrode reaction kinetics model of duplex stainless steel in flowing chloride solution was found on the basis of electrochemical corrosion theory, which was used to explain EIS of duplex stainless steel in flowing chloride solution. The dominant role of electrochemical corrosion in the process of flow-induced corrosion of duplex stainless steel electrode in flowing chloride solution was further understood.

关 键 词：双相不锈钢 流动氯化物流动腐蚀 电化学阻抗谱 电化学腐蚀动力学 

分 类 号：TG172.9[金属学及工艺—金属表面处理] TF111.52[金属学及工艺—金属学]