Determination of susceptibility to intergranular corrosion of UNS 31803 type duplex stainless steel by electrochemical reactivation method

Abstract

Specimens taken from a hot-rolled cylindrical duplex stainless steel (DSS) bar with 22% Cr grade were solution annealed at 1050 ° C and then aged at 725 ° C from 100 to 31622 min for sensitization treatment. Double loop electrochemical potentiodynamic reactivation and standard weight loss immersion acid tests were conducted. The solution-annealed samples were found unsensitized. Those samples aged for 100 and 316 min were less sensitized whereas samples aged for 1000 min and especially those aged for 3162, 10000, and 31622 min were heavily sensitized. The degree of sensitization (DOS) can be attributed to higher contribution of chromium- and molybdenum-depleted areas resulting from intermetallic phases. © 2012 Mehmet Emin Arikan et al.