Comparison of test methods for crevice corrosion propagation and repassivation potential of stainless steel AISI 316

The crevice corrosion propagation modes and repassivation potential of stainless steel AISI 316 in chloride solution were compared using cyclic potentiodynamic polarization (CPP), potentiodynamic-galvanostatic-potentiodynamic (PD-GS-PD) and Tsujikawa– Hisamatsu electrochemical (THE) methods. The PD-GS-PD method was found to be the most conservative electrochemical technique which delivered the lowest repassivation potential value in a relatively short time. The crevice corrosion propagation modes in these three electrochemical methods were also compared with crevice corrosion propagation mode in galvanically coupled small area stainless steel AISI 316 anode with large area titanium cathode. The crevice corrosion propagation mode achieved in galvanically coupled AISI 316 anode at open circuit potential simulated the crevice corrosion propagation mode in real systems. The crevice corrosion propagation modes achieved in PD-GS-PD and THE methods mimicked the crevice corrosion propagation in real systems.