DETERMINATION OF CORROSION AND ELECTRO-KINETIC PARAMETERS FROM POTENTIOSTATIC PULSE MEASUREMENTS

A fast method of calculating corrosion current density and Tafel slope s is described in the present work, which uses six pairs of values of potential-current obtained by means of potentiostatic pulses. An expre ssion for the corrosion density is deduced where the Tafel slopes are implicit. The method can be used to values of greater or smaller polar ization than 10 mV. Comparing the proposed method with other methods, by using pulse data for iron in H2SO4 0 5 M, it is observed that the n ew method is more precise. A quick method for calculating electrokinet ic parameters (transfer coefficient, exchange current density and stoi chiometric number) is given, using data of six pairs of current-overpo tential values. The method is valid for redox reactions in equilibrium of any order which are controlled by charge-transfer mechanisms. The method is applied with experimental values of the redox reaction Fe3+/ Fe2+ over platinum electrodes. The proposed method is more precise bec ause it uses more polarization points than other published methods. Th e above method can be used with values of polarization greater or smal ler than RT/F, in the region where the process control is by charge tr ansfer.