Sigma Phase in duplex stainless steel?
-Never with EXPANITE!
Duplex stainless steels contain 2 types of microstructure, austenite and ferrite. Hence the name duplex. In simple terms, the combination of these two phases is what causes duplex alloys to be highly sensitive with respect to the formation of the so-called “Sigma phase” (s-phase), because the s-phase primarily will form in the boundary between austenite and ferrite, growing into the ferrite.