Texture evolution of cold rolled and annealed Fe-24Mn-3Al-2Si-1Ni-0.06C TWIP steel

Highlights: → Slip and micro-shear banding contribute to the development of Brass orientation. → Annealing twins evolve since the early nucleation stage. → F orientation forms upon recrystallisation due to relatively random nucleation. → Second order twinning and favoured growth relation lead to Rotated Copper component. → The modified Hall-Petch equation adequately predicts the 0.2% proof stress. - Abstract: The microstructure and texture evolution of 42% cold-rolled Fe-24Mn-3Al-2Si-1Ni-0.06C TWinning Induced Plasticity (TWIP) steel is investigated during isochronal annealing at temperatures between 600 and 850 deg. C. In the cold rolled condition, bulk texture returned the distinctive α-fibre for low stacking fault energy materials, with higher intensities for Goss ({1 1 2}< 0 1 1 >) compared to Brass ({1 1 1}< 1 1 2 >). A comparison between bulk and micro-textures, showed a significant slip contribution to the development of the Brass orientation, along with a possible role for micro-shear banding. Annealing twins contribute to recrystallisation from the early stages of nucleation and participate in generating new orientations thereafter. Unlike texture studies on other austenitic steels, the F ({1 1 1}< 0 1 1 >) and Rotated Copper ({1 1 2}< 0 1 1 >) orientations were detected in this work. The former is due to a more homogeneous distribution of nucleation sites, while the latter can be ascribed to second order twinning and the preferred-growth 30o <1 1 1> relation with the Brass rolling component. Based on the microstructural parameters from Electron Back-Scattering Diffraction (EBSD), the modified Hall-Petch (H-P) relation was successfully applied to the 0.2% proof stress.