Monte Carlo simulation of elongated recrystallized grains in steels

A Monte Carlo simulation technique was employed to model certain aspects of recrystallization in steels, namely the formation of elongated grain shapes, the control of grain size by particle pinning, and the dependence of texture evolution on particle density and stored energy. The first set of simulations investigated the growth of a single nucleus in a bi- or tri-crystal matrix and focused on grain boundary character. When low angle boundaries are present between the matrix and the nucleus, the recrystallizing grain grew abnormally into the neighboring matrix grains. However, if the matrix grains had a large difference in stored energy at a boundary, the movement of the grain boundary was hindered; the recrystallized grain cannot grow into the matrix but instead grew along the boundary. Hence elongated grains could be obtained with a special orientation relationship at the boundary without dispersed fine particles. Particle pinning was examined in the second set of simulations. Particles were found to retard recrystallization only for low stored energies; the largest grain was obtained at the critical condition for recrystallization. Thus if nucleation sites are restricted to low densities, larger elongated grains are obtained. Both particle pinning and stored energy levels influenced texture evolution during recrystallization.