Orientation Dependent Recovery in Interstitial Free Steel

摘要

Cold rolled (40, 60 and 80% thickness reductions from hot-band) interstitial free (IF) steel samples were recovered at 500℃ for different times (15 min to 32 h). The recovery kinetics, studied through a combination of X-ray line profile analysis and high resolution electron diffraction, were best represented by logarithmic relationship. Though the kinetics was dependent on the prior deformation, γ(ND//<111>) fibre clearly had stronger recovery than θ(ND//<100>) fibre. Recovery was observed, statistically to create grain interior strain localizations: an orientation independent phenomenon. Increase in misorientation across such strain localizations was, however, orientation dependent. This was responsible for enhanced in-grain misorientation in recovered γ-fibre grains/bands. Extended recovery of 80% pre-deformed samples also led to coarsening of γ-fibre bands: strain induced boundary migration (SIBM) or uniform movement of γ-fibre boundaries into neighbouring non γ-fibre orientations.