Abstract: A static recrystallization behavior between the rolling passes of a martensitic heat-resistant stainless steel 403Nb has been studied by OM, TEM and double-hit thermo-mechanical simulator to explore the effects of deformation temperature, strain rate, strain and the prior austenite grain size. The results show that increases of deformation temperature and strain rate and strain can promote the static recrystallization of 403Nb steel. Static recrystallization also proceeds faster when the prior austenite grain size is smaller. Microstructural observation indicates that the volume fraction of static recrystallization increases with prolonged interval of the rolling passes. Strain-induced precipitation can lead to an appearance of a platform in the kinetic curve of static recrystallization. Different from the conventional micro-alloying steel, the strain-induced precipitates in 403Nb steel during hot rolling are carbides containing Nb and Cr.

Key words: 403Nb, Static recrystallization, Microstructural evolution, Strain-induced precipitation