Static Recrystallization Behavior of Twin Roll Cast Low-Carbon Steel Strip

Abstract

The static recrystallization kinetics of low-carbon steel cast strip was investigated by means of interrupted hot tensile tests. As-cast strip was reheated and soaked and its austenite grain size was similar to the width level of the as-cast columnar structure. The tests were carried out on Gleeble-3500 thermomechanical simulator. The deformation temperature is in the range of 800 to 1200 °C with strain rate of 0.01 to 1 s −1. The prestrain is fixed at 0.04 to 0.12, and the inter-hit delay time varies from 1 to 3000 s. Effect of deformation conditions and initial micro-structure on static recrystallization behavior was investigated. The activation energy (Q six) and Avrami exponent ( n) of static recrystallization were determined to have 241 kJ/mol and 0.54 respectively by linear regression of the experimental results. A kinetics model was proposed to describe the static recrystallization kinetics in low-carbon steel cast strip. The predicted softening fractions are in good agreement with the experimental results, indicating that the proposed equations can give an accurate estimate of the softening behaviors for the low-carbon steel cast strip.