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

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 °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 30° 〈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.

► 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.