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

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 degrees C-1200 degrees C and at strain rate of 0.001 s(-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 484 kJ/mol. Dynamic recrystallization was delayed when the logarithm of the Zener-Hollomon parameter fell within 13-15 s(-1). This retardation was attributed to the segregation of substitutional impurity elements, mainly phosphorus, to grain boundaries where recrystallization is originally initiated. (C) 2011 Elsevier B.V. All rights reserved.