Evaluation of the intergranular corrosion susceptibility of UNS S31803 duplex stainless steel with thermoelectric power measurements

In this study, the use of thermoelectric power (TEP) measurements as a nondestructive method for the determination of the degree of sensitization (DOS) in UNS S31803 duplex stainless steel (DSS) is presented. Samples were aged for times up to 240 h and subjected to the double loop electrochemical potentiokinetic reactivation (DL-EPR) test to calculate the DOS induced. The correlation between TEP and the DOS evaluated by the DL-EPR method indicates that the TEP coefficient is sensitive to gradual microstructural changes produced by thermal aging and may be used to monitor the susceptibility to intergranular corrosion in UNS S31803 DSS.

► Thermoelectric power is sensitive to thermal damage.
► Thermoelectric power is sensitive to DOS.
► Thermoelectric power as NDE detection technique.
► Sigma phase precipitation is detected at early aging stages.