The microstructure and flow behavior of 2205 duplex stainless steels during high temperature compression deformation

The deformation behavior of a 2205 duplex stainless steel has been investigated over the range of temperatures from 850 to 1250 °C and strain rates from 0.005 to 5 s−1 by compression testing. The results show that the characteristics of flow stress curves and deformed microstructures mainly rely on the variations of deformation temperature and strain rate. At a low strain rate of 0.005 s−1, the flow curve characteristics of dynamic recrystallization (DRX) were exhibited with deformation temperatures at 950 and 1050 °C, whereas the region of stable flow stress became narrower as the strain rate increased to 0.5 s−1 at 850 and 950 °C, leading to more work hardening deformed microstructures formation. The leading softening effect in flow curves is characterized by dynamic recovery (DRV) with higher deformation temperature at 1150 and 1250 °C, and the ferrite grains of DRV became coarser simultaneously. As the strain rates are 0.005 and 0.5 s−1, the corresponding austenite content shows the highest at 950 and 1050 °C respectively, indicating the best effect of austenite DRX, which was weakened by increasing strain rate to 5 s−1. Meanwhile, the values of apparent activation energy and hot deformation equation have been obtained by hot deformation equation analysis.