Dynamic recrystallization behavior of low-carbon steel during hot rolling process: modeling and simulation

Abstract

DRX (dynamic recrystallization) behavior, which can improve the product's microstructure and enhance its performance, is vital in the high-temperature plastic deformation of metal materials. In this paper, single-pass hot compression tests were carried out on a Gleeble-3800 thermo-mechanical simulator to investigate the DRX behavior of a low carbon steel at a deformation temperature of 900°C–1100 °C and a strain rate of 0.01s−1-0.1s−1. The effect of temperature and strain rate on DRX was investigated based on the direct connection between DRX and dynamic softening behavior. The Zener–Hollomon model revealed the relationship between temperature, strain rate, and stress was established. A DRX kinetic model was established for the hot-rolled condition based on the relationship between the characteristic parameters of DRX and temperature and strain rate. The results showed that the predicted and tested values were in good agreement. The established DRX kinetic model was embedded into DEFORM-3D software to simulate the DRX behavior of the hot rolling process of a round bar. The results showed that the fraction of DRX of the whole section of the bar after hot rolling showed noticeable non-uniformity. The DRX ability of the surface area in direct contact with the roller is significantly lower than in other areas. This phenomenon is related to the high-temperature deformation behavior during the rolling process. Reducing the roller speed has almost no effect on this phenomenon; increasing the rolling temperature can significantly improve this phenomenon.

Keywords

• Bar rolling
• Dynamic recrystallization
• Hot deformation
• Numerical simulation
• Physical simulation