Dynamic recrystallization behavior of a superaustenitic stainless steel containing 16%Cr and 25%Ni

► Grain boundary bulging is responsible for the nucleation of dynamic recrystallization in superaustenitic stainless steels. ► The average value of apparent activation energy for hot deformation is 484kJ/mol. ► An anomalous increase is seen in the decreasing trend of the critical and peak strains with increasing deformation temperature. It is seen when lnZ is around 14.3. ► The anomalous increase of the characteristic strains is due to the dragging effect of phosphorous on grain boundaries. Dynamic recrystallization behavior of austenite in a superaustenitic stainless steel containing 16%Cr and 25%Ni was studied using hot compression tests in a temperature range of 900°C–1200°C and at strain rate of 0.001s−1–1s−1. The initiation and evolution of dynamic recrystallization were investigated by microstructural analysis. The effect of deformation temperature and strain rate on the flow stress during dynamic recrystallization was studied using the hyperbolic sine equation. The apparent activation energy for the hot deformation was calculated to be about 484kJ/mol. Dynamic recrystallization was delayed when the logarithm of the Zener–Hollomon parameter fell within 13–15s−1. This retardation was attributed to the segregation of substitutional impurity elements, mainly phosphorus, to grain boundaries where recrystallization is originally initiated.