Abstract
The deformation behavior of the Incoloy 926 super-austenitic stainless steel at 1000–1150 °C and 0.001–10 s^–1 was investigated. The corrected true stress-true strain curves were obtained by compensating the interfacial friction in the flow stress-strain curves. The interfacial friction increased the flow stress, and this increase was more pronounced at higher strains. According to the constitutive model, the activation energy varied from 328 to 384 kJ mol^–1 with respect to strain. The mechanical parameters, peak stress and peak strain, critical stress and critical strain, were described by clearer equations with the temperature and strain rate. Moreover, based on the processing maps and the microstructural observation, the unsafe deformation domain where the localized plastic flow occurred was validated at above 1 s^–1, the favorable process at 1100 °C and 0.1 s^–1 where fine and homogeneous grains can be obtained was determined simultaneously.

Key words
super-austenitic stainless steel, hot deformation, constitutive model, processing maps

Full text (1792 KB)