  The present article proposes a detailed study of recrystallization of
zircaloy-4 under hot forming conditions by means of experimental and numerical
tools. Thermomechanical tests and characterization campaigns that have been
necessary for this work are described. Then, the different microstructure
evolution mechanisms are characterized, from the simplest one to the most
complex. Grain growth kinetics is quantified and the influence of second phase
particle population is analyzed. Then, a complete study of dynamic and
post-dynamic recrystallization is provided. The occurrence of a continuous
mechanism is confirmed and the influence of thermomechanical conditions upon
recrystallization is assessed. Later, the numerical framework used to simulate
grain growth, continuous and post-dynamic recrystallization is presented. After
having successfully reproduced the grain coarsening kinetics with and without
second phase particles, the model is used to describe continuous dynamic
recrystallization and post-dynamic recrystallization from an initial equiaxed
and fully recrystallized microstructure. The agreement between experimental and
numerical results is assessed in detail. Finally, post-dynamic
recrystallization is simulated, starting from two deformed microstructures
characterized by electron back-scattered diffraction technique and immersed
into simulations. This allows to discuss and reproduce the influence of initial
microstructure.
