Research on high temperature deformation behavior of low carbon steel based on processing map

The high temperature deformation behaviors of low-carbon steel QD08 were investigated by hot compression tests over temperatures from 1000°C to 1200°C and strain rates from 0.1 to 10 s？1. In order to describe the flow characteristics, a constitutive equation was developed and the relation between the flow stress and Zener–Hollomon parameter was successfully analyzed via the hyperbolic sine function under the whole range of deformation condition. It can be found that the critical strain ε c increases with parameter Z increasing; the critical conditions for onset of dynamic recrystallization is ε > ε c = 61 . 9381 Z 0 . 1033 . Based on dynamic material model and Prasad’s instability criterion, the power dissipation map and the instability map were developed. The results show that the security domain of hot deformation for low-carbon steel QD08 at the temperature range between 1070°C and 1100°C, and strain rate range of around 5–10 s？1, with a higher power dissipation factor, maintains a smooth variation, under stable deformation conditions. On the basis of processing map, the optimal deformation processing parameters are the hot deformation temperature range from 1070°C to 1100°C, and strain rate range from 5 to 10 s？1