Modeling recystallization kinetics in a deformed iron single crystal

Abstract

The kinetics of recrystallization of a (111) {$\left[ {\bar 1\bar 12} \right]$} single crystal of pure iron deformed 70 pct by rolling were characterized experimentally at temperatures between 450°C and 600°C, using quantitative metallography. The method of Laplace transforms was applied to the overall recrystallization kinetic behavior to separate nucleation from interface migration kinematics. A comprehensive nucleation and growth model was developed to explain all observations quantitatively. the model consisted of the following important features: (a) nucleation sites were distributed randomly; (b) nucleation was site-saturated and occurred with no practical incubation time at all annealing temperatures; (c) recrystallized grains grew three-dimensionally and were spheroidally shaped; (d) all recrystallized grains grew at approximatelly the same rate within experimental error; and (e) interface migration rates were not constant but decreased with time according to at ^−0.38 law at all temperatures. The time dependency of the interface migration rate was rationalized in terms of deformation-induced, nonuniform distribution of stored energy, Recovery processes competing with recrystallization were evident at long annealing times at the two lowest annealing temperatures.