The temperature-dependent pitting and repassivation behaviors of UNS S31803 duplex stainless steel in chloride solutions.

Highlights • An improved electrochemical method named thermal pulse technique was designed. • The CPT and repassivation temperature (T r) were measured in one thermal pulse. • The T r presented an inverted V-shape trend with the rise of cooling rate. • A model was proposed for the variation of T r in different thermal pulses. • The repassivation behavior was discussed according to the data of T r and E rp. Abstract An improved electrochemical method named thermal pulse technique was designed to measure the current flowing from a potentiostatically maintained UNS S31803 electrode in 1 M NaCl solution, while various thermal pulses were applied on the solutions. Both the critical pitting temperature (CPT) and the repassivation temperature (T r) were measured in one thermal pulse. The T r data presented an inverted V-shape trend as the cooling rate decreased. Both the CPT and T r values declined after multiple thermal pulses. The cyclic potentiodynamic polarization curves present a sharp transition of pitting and repassivation potential at the temperature ranged between the CPT and T r. [ABSTRACT FROM AUTHOR]