On the modified kinetics model describing the dynamic recrystallization behavior during hot deformation of Incoloy 925

The isothermally hot compression tests of Incoloy 925 were conducted over a temperature range of 900-1150 & DEG;C and strain rate of 0.01-10 s-1 to investigate the dynamic recrystal-lization (DRX) kinetics behavior and its effect on the microstructure evolution. The values of DRX fraction under different deformation conditions were evaluated through electron backscatter diffraction analysis combined with artificial neural network approach. The DRX behavior was also investigated based on the traditional Avrami-DRX kinetics model and the strain-rate dependent Avrami-DRX kinetics model modified by genetic algorithm & BiHill function, respectively. The results reflected that the modified model shows a better robustness to describe the DRX behavior under the deformation condition with a relatively low DRX fraction or at the domain with higher strain rate. Besides, the crystallographic orientation parallel to the compressive direction tends to form the <101> fiber highlighted by the deformed grains, while the predominant orientations of DRX grains show a ten-dency towards <001> fiber. Moreover, the transition rule of the main DRX mechanism was further studied by discussing the linear relationship between the Z parameter and DRX grain size.& COPY; 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The dynamic recrystallization (DRX) kinetics behavior and its effect on the microstructure evolution of Incoloy 925 were investigated through isothermally hot compression tests. The DRX fraction was evaluated under different deformation conditions using electron backscatter diffraction analysis combined with artificial neural network approach. Two different models, namely the traditional Avrami-DRX kinetics model and the strain-rate dependent Avrami-DRX kinetics model modified by genetic algorithm & BiHill function, were used to study the DRX behavior. The results showed that the modified model exhibited better robustness under conditions with relatively low DRX fraction or at high strain rates.