恒电量瞬态扰动测量Tafel斜率及数据积分处理

提出了一个三参数积分法拟合恒电量强极化数据以测定Tafel斜率的新方法.实验证明,恒电量瞬态扰动测量碳钢在酸溶液中的腐蚀,获得的Tafel斜率与消除了溶液电阻影响的Tafel外推结果有很好的一致性,说明恒电量法有效地消除了溶液电阻对该体系测量结果的影响,并且通过电化学和失重实验验证表明,这种快速测量可以获得准确的腐蚀速率.这种新的恒电量强极化积分算法相对微分法的优势体现在算法简捷和用于数值计算的数据具有较高的信噪比,因此能够提高测量精度.

Determination of Tafel Slopes from Coulostatically Induced Transients and Its Integral Alogrithm

The mathematical model of a three-parameter method, based on an integral formulation, for analyzing the coulostatically induced transients is developed. This method can compute the Tafel slopes ba or bc and corrosion current density ic. The validity of the method is confirmed by the observation that the values of Tafel slope measured by coulostatic method are coincident with those obtained by Tafel lines extrapolation method with eliminating influence of IR drop, and the comparison of results obtained by solution analysis and electrochemical measurements shows that the method provides a faithful representation of corrosion behavior. The integral method has the advantages over differential method due to its simplicity and higher signal/noise ratio, so that the numerical algorithm gives the possibility of higher precision of corrosion measurements.