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对钝态金属腐蚀体系推导了不含近似处理的充电曲线方程式.提出了使用数值微分和线性回归求解体系电化学参数的计算方法.其优点是不需考虑“线性区”问题,而且可以直接求出腐蚀电流密度.“,”Charge curve analysis technique (CCAT) has obvious merits for study of the systems with long time constant, such as passivated metals. But conventional CCAT is limited to apply in mini-polarization range and gets linear polarization resistance only. A charge curve equation without linear simplification for passivation/corrosion systems is derived and it is proved that the reciprocal of differential of charge curve is linear with exponential function of time. Based on the galvanostatically measured charge curve data at equal time intervals, numerical deferentials at sampling times are calculated and two linear regression operations are made. Then electrochemical parameters of the system (corrosion current density and Tafel slope) may be obtained. This method is not restricted by “liner polarization zone” and the corrosion current density could be directly calculated.