چكيده به لاتين
The hot deformation behavior of a super bainitic steel was studied at temperatures of 950–1100 ℃ and strain rates of 0.001–1s^(-1). The flow behavior, constitutive equations, dynamic recrystallization (DRX) characteristics, and processing map were respectively analyzed in detail. It is found that the flow stress increases with increasing the strain rate and decreases with increasing the temperature, and the single-peak DRX can be easily observed at high temperatures and/or low strain rates. where the activation energy for hot deformation is 451.334 kJ/mol. In addition, the DRX evolution and the critical conditions for starting DRX were discussed. After examining the process maps and microstructure obtained from the hot pressure test, it is determined that must suitable temperature range for deformation is for this steel at temperature of 950 ℃ and the strain rates 1 s^(-1) and 0.01 s^(-1), at temperature of 1000 ℃ and the strain rates 0.1 s^(-1) and 0.01 s^(-1), at temperature of 1050 ℃ and the strain rate 0.01 s^(-1), at temperature of 1100 ℃ and the strain rate 1 s^(-1) also in this domain the efficiency of the process is maximum and instability doesn't happen. Also (at temperature of 950 ℃ and the strain rate 0.1 s^(-1), at temperature of 1000 ℃ and the strain rate 1 s^(-1), at temperature of 1050 ℃ and the strain rates 1 s^(-1) and 0.1 s^(-1), at temperature of 1100 ℃ and the strain rates 0.1 s^(-1) and 0.01 s^(-1) and 0.001 s^(-1)) instability was observed at microstructure which indicates condition is not suitable for deformation.
