Dynamic Recrystallization and Flow Behavior in Low Carbon Nb–Ti Microalloyed Steel

Abstract

Single‐pass hot compression tests are performed to study the hot deformation behavior of a low carbon microalloyed steel at temperatures in the range of 950–1050 °C and strain rate from 0.01 to 0.5 s–1. Based on true stress–strain data, the effect of strain rate and temperature on the flow behavior of this steel is analyzed and peak stress is determined as well. The partial derivative of the strain hardening rate to stress is used to determine the critical stress. The value of activation energy and the ratio of critical stress (strain) to peak stress (strain) are estimated. The relationship between characteristic points and Zener–Hollomon parameter is established. The kinetic model for the calculation of volume fraction of dynamic recrystallization is also established. The strain dependence of material constants are determined from fifth‐order polynomials and the flow stresses under different deformation conditions are predicted, consistent with the experimental results.