Determination of activation energy for static recrystallization using multipass continuous cooling torsion test

Abstract

Two microalloyed steels (Nb/Ti low carbon and V medium carbon) were tested by means of continuous cooling multipass tests on high temperature torsion tester, with aim to investigate the recrystallization kinetics. Multistage continuous cooling torsion tests (modified Boratto test for determination of Tnr temperature), have been used to evaluate the interpass recrystallization data. The determination of activation energy for static recrystallization, Q(SRX),. was limited to temperatures above Tnr temperatures, i.e. temperature range in which microalloying elements are in solid solution. Tnr temperatures were, in all cases, related to equal amount of recrystallized fraction, enabling plotting lnt vs. l/T dependence. Activation energies determined for both steels have close values and show good agreement with previously published data.