A comprehensive study of the pitting corrosion mechanism of lean duplex stainless steel grade 2404 aged at 475 °C

Abstract Recent findings reveal that Cr nitride precipitation during lean duplex stainless steel (LDSS) 2101 aging at 475 °C is more detrimental to its corrosion resistance than Cr depletion caused by spinodal decomposition. Thus, the purpose of this study is to understand the role of Cr depletion caused both by evolution of spinodal decomposition and precipitation of other Cr-rich phases in pitting corrosion of LDSS 2404 aged at 475 °C. Our findings indicate that, although Cr carbide and nitride precipitation occur at 475 °C in LDSS 2404, the main cause of Cr depletion and loss of pitting resistance is spinodal decomposition.