The Influence of Chromium Nitrides Precipitation on the Fatigue Behavior of Duplex Stainless Steels

This paper studies the fatigue behavior at room temperature of UNS S32205 and UNS S32750 duplex stainless steels (DSSs) under two thermal treatments. In both types of DSSs, thermal treatments at high temperature followed by water quenching (TTW) produces the precipitation of Cr2N within the ferrite phase. The amount of Cr2N increases mainly with the ferritic grain size independently of the nitrogen content. This nitride precipitation hardens the ferritic phase and produces a detrimental effect on the fatigue life of both steels.