Use of Potentiokinetic and Potentiostatic Methods for the Determination of Characteristic Potentials for Pitting Corrosion of an Fe–Cr Alloy

Potentiokinetic and potentiostatic methods were used to determine the pitting potential, Ep, and the potential for protection against pitting, Epp, for a 13 Cr steel in a deaerated solution of 3% NaCl. It was found that potentiokinetic methods gave pitting potentials that were far too noble and protection potentials that were far too base. Kinetic investigations by the potentiostatic method seem to offer the best likelihood of obtaining correct values for the pitting potential.