Hot deformation behavior and microstructure features of FeCrAl-ODS alloy

The hot deformation behavior of FeCrAl-ODS alloys at temperatures of 1050-1200 degrees C and strain rates of 0.001-1 s(-1) was investigated. The peak stress of FeCrAl-ODS alloy during hot deformation decreased with increasing temperature and decreasing strain rate. In addition, the stress-strain curves show a dynamic softening phenomenon according to the shape of the flow curves. Based on the Arrhenius-type model, a constitutive equation and processing map of FeCrAl-ODS alloy were established. Thereafter, we proposed optimum processing parameters of 1200 degrees C and 0.001 s(-1) based on the processing map. Compared with FeCrAl alloys, there was no significant phenomenon of grain coarsening during hot deformation in FeCrAl-ODS alloy. In the electron backscattered diffraction images, both recrystallized and recovered grains were observed in the matrix under different deformation conditions. The fraction of dynamically recrystallized grains in the matrix under the deformation of 1100 degrees C/0.001 s(-1) (42.5%) was significantly higher than that at 1200 degrees C/0.001 s(-1) (10.6%), which was consistent with the stress-strain curves.

Automated summary

The hot deformation behavior of FeCrAl-ODS alloys was investigated at high temperatures and strain rates. The peak stress of the alloy decreased with increasing temperature and decreasing strain rate. The stress-strain curves exhibited a dynamic softening phenomenon. A constitutive equation and processing map were established, and optimum processing parameters were proposed. Compared with FeCrAl alloys, FeCrAl-ODS alloys did not show significant grain coarsening during hot deformation, and both recrystallized and recovered grains were observed.