Dynamic recrystallization of austenite in microalloyed high carbon steels

Hypereutectoid steels of 1% carbon, alloyed with high silicon and microalloying levels of vanadium were subjected to dynamic recrystallization. It was found that an increase in carbon and vanadium content leads to smaller grain size. To characterize the dynamic recrystallization behavior of these steels, compression tests were performed over the temperature range 900-1050 degreesC using strain rates of 0.01, 0.1 and 1 s(-1). Equations were generated that can be used to predict the critical strain for dynamic recrystallization. Of interest is the finding that there is an activation energy for deformation specifically associated with dynamic recrystallization (i.e. peak strain). This activation energy associated with the peak strain is lower than that associated with the steady state stress. This is contrary to Sellar's original observation that the peak strain is a function of the activation energy for deformation according to the Zener-Hollomon relationship. (C) 2003 Elsevier Science B.V. All rights reserved.