Experimental investigation via torsion testing and simulation of static recrystallization of ferrite in ultra-low carbon steel

Abstract

High-strain cold deformation introduces high driving forces for recrystallization, i.e., high dislocation densities, which in turn remarkably alters the microstructure. The static recrystallization behavior of ultra-low carbon steel during annealing, following cold torsion tests with engineering strain greater than 2, is experimentally investigated. Metallographic and EBSD analysis are used to evaluate the resulting microstructure after deformation and annealing. The recrystallized grain size decreases with increasing strain until reaching a saturation point. The study reveals that torsion tests are well suited to investigate the recrystallization behavior for a wide range of strain in ferritic steel. The experimental results are compared to computer simulations using a mean-field recrystallization model implemented in MatCalc. By using an extended Kocks-Mecking model approach and considering the subgrain boundary misorientation, the simulations consistently reproduce the experimental results, validating the accuracy of the model.