Strain energy method to determine static recrystallization volume fraction of microalloyed steel

Abstract

Double compression method is an effective method to determine static recrystallization volume fraction of materials because there is a marked difference in flow stress between two passes, which is caused by static recrystallization. And now offset method that is based on some specific flow stress is widely used. However, this method is not suitable to determine static recrystallization volume fraction for all the materials, especially for those alloyed steels. As the measurement of yield or flow stress is not very sensitive to a subtle change in precipitation, strain energy is the integration of the flow stress and so it is more sensitive to the subtle change and so this method could be better. This study aims to present strain energy method to determine static recrystallization volume fraction in details by performing uniaxial compression test on a microalloyed steel. And it was found that there were two points worth to note while performing this method: one is that if work hardening plays a dominant role during compression process, static recrystallization volume fraction can be determined by analyzing double compression curve and its extrapolation, on the contrary if dynamic softening plays the dominant role, the static recrystallization volume fraction has to be determined with the assistance of curve from single pass compression test.