Torsion textures produced by dynamic recrystallization in α-iron and two interstitial-free steels

Two interstitial-free (IF) steels and a high-purity alpha-iron were deformed in torsion over the temperature range of 600 degrees C to 840 degrees C, and the textures produced were measured using conventional X-ray techniques. The conditions were chosen so that dynamic recrystallization (DRX) would take place in the ferrite and static recrystallization would be avoided during cooling after deformation. The DRX textures differ from those observed at room temperature and are dominated by the D1 (11 (2) over bar)[111], D2 (<(11)over bar>2)[111], and E2 (0 (1) over bar 1)[111] components. The D2 becomes increasingly important as the strain is increased, which leads to weakening of the D1 and disappearance of the E2 at large strains. Texture simulations were carried out using a DRX model based on sequential deformation, nucleation, and growth steps. The types of oriented nucleation and selective growth required to reproduce the experimentally observed textures are discussed. The simulations indicate that the low-energy nucleation mechanism plays a dominant role in the formation of bcc DRX textures. The results are also interpreted in terms of the continuous (in situ) and discontinuous mechanisms of dynamic recrystallization.