Nucleation mechanisms of dynamic recrystallization for G3 alloy during hot compression

摘要

Dynamic recrystallization(DRX) mechanisms of a nickel-based corrosion-resistant alloy, G3, were investigated by hot compression tests with temperatures from 1050 to 1200 ℃ and strain rates from 0.1 to 5.0 s^(-1).Deformation microstructure was observed at the strain from 0.05 to 0.75 by electron backscatter diffraction(EBSD) and transmission electron microscope(TEM).Work hardening rate curves were calculated to analyze the effect of deformation parameters on the nucleation process.Results indicate that strain-induced grain boundary migration is the principal mechanism of DRX. Large annealing twins promote nucleation by accumulating dislocations and fragmenting into cell blocks. Continuous dynamic recrystallization is also detected to be an effective supplement mechanism, especially at low temperature and high strain rate.