恒电量法测定电化学腐蚀动力学参数的原理与测量系统

THE PRINCIPLE OF MEASURING KINETIC PARAMETRS OF ELECTROCHEMICAL CORROSION SYSTEM BY COULOSTATIC PERTURBATION METHOD AND ITS MEASURING SYSTEM

研究了恒电量腐蚀速率仪,建立了恒电量仪与微计算机联机在线测量系统,可用以评定涂装金属的耐蚀性.使用该测量系统,只需一次微极化即可获得重要参数值-极化阻力 R、界面双层微分电容 Cl溶液电阻 R_S 及涂膜层电阻 R、涂膜层电容 Cl。对于非涂装体系,经两次强极化正可获得塔菲尔常数 b、b,结合 Stern-Geary 方程便可算出腐蚀电流 I。

A corrosion rate meter for coulostatic perturbation method has been made and a on-line measuring system combined with microcomputer is set up.It can be used to evaluate the corrosion resistance of coated metals by coulostatic perturbation method. Important parameters such as R_p,R_f,C_u,C_f and R_s can be obtained in experiment with only for once weak polarization.For uncoated metal systems,TAFEL slopes b_a and b_c can be obtained with twice strong polarization,and the corrosion current I_(corr)can be calculated with the aid of STERN-GEARY equation.