Evaluation of Microstructural Effects on the Degree of Sensitization (DOS) of a UNS S31803 Duplex Stainless Steel Aged at 475 degrees C

摘要

In this study, microstructural and electrochemical behavior of a UNS S31803 duplex stainless steel aged at 475 degrees C were investigated. Hardness values increased with aging at 475 degrees C and evidence of alpha prime (alpha') phase formation was confirmed by transmission electron microscopy analysis. Double loop electrochemical potentiokinetic reactivation measurements in a 2 M H2SO4 + 0.5 M NaCl + 0.01 M KSCN solution showed an increase in the degree of sensitization values, mainly for the sample aged for 360 h at 475 degrees C. Moreover, the results suggest that alpha' phase formation occurred via spinodal decomposition mechanism.