Evolution of microstructure and mechanical properties during annealing of cold rolled Fe-24Mn-3Al-2Si-1Ni-0.06C TWIP steel
TWinning Induced Plasticity (TWIP) steels have been recently developed as a promising material for automotive applications. In the present work the recrystallisation behaviour of 42% cold-rolled Fe-24Mn-3Al-2Si-1Ni-0.06C TWIP steel was investigated during isochronal annealing for 300s via microhardness testing, Electron Back-Scattering Diffraction (EBSD) and uniaxial tensile testing. EBSD internal misorientation data corroborates recrystallised fraction estimates from microhardness measurements. Annealing twins play an important role during recrystallisation by bulging at the deformed grain boundaries during nucleation and generating twin related orientations. During uniaxial tension, the recovered condition recorded three work hardening regions while all partially recrystallised samples exhibited four regions. A modified Hollomon scheme is suggested to account for the effect of strain on microstructure refinement.