A COMBINED MODEL OF ORIENTED NUCLEATION AND SELECTIVE GROWTH FOR THE RECRYSTALLIZATION OF INTERSTITIAL-FREE STEELS

A combined model of oriented nucleation and selective growth is propos ed to describe primary recrystallization in interstitial-free (IF) ste els. The model includes oriented nucleation at high Taylor-factor orie ntations together with orientation transformations (OTs) about selecte d [110] axes over a misorientation range that includes the Sigma 9, Si gma 11, Sigma 19a, and Sigma 33a type coincidence site lattice (CSL) r elationships. It is shown that only one or two of the six possible [11 0] rotation axes operate in a given grain and at a particular grain bo undary. These are the ones closest to the maximum shear stress (MSS) p oles for cold rolling. The present study suggests that IF steels displ ay particularly sharp textures (compared to plain C steels), because t he factors that favor the selection of the transformation axes and the more rapid growth of CSL boundaries operate more effectively in these materials.