Hot deformation behavior of an Nb- and N-bearing austenitic stainless steel biomaterial

An austenitic stainless steel (ISO 5832-9) with an intermediate level of stacking fault energy (SFE) was torsion-deformed at temperatures ranging from 900 to 1200 °C and at strain rates ranging from 0.01 to 10 s−1. The hot deformation behavior was analyzed based on variations in the shape of flow stress curves, a constitutive equation, processing maps and the final microstructures. In large deformations, a region of instability in the temperature-strain rate space was observed at low temperature and high strain rates, and domains of easy processing were determined at high and intermediate temperatures and low strain rates. The final microstructure was analyzed based on the evolution of the internal structure over time in response to hardening and softening mechanisms such as work hardening, recovery and recrystallization.