MODELING THE MICROSTRUCTURAL CHANGES DURING HOT TANDEM ROLLING OF AA5XXX ALUMINUM-ALLOYS - PART III - OVERALL MODEL DEVELOPMENT AND VALIDATION

Part III of this article presents the overall mathematical development for the microstructural and textural evolution during industrial hot tandem rolling of AA5182 and AA5052 alloys and validation of the mathe matical model, by comparison to both industrial data and information f rom the literature. The model consists of a plasticity module to simul ate the temperature and deformation in the roll bite and an interstand module to characterize the changing microstructure, texture, and temp erature in the strip between the rolling stands. The plasticity module was developed using a commercial finite-element package, DEFORM, a tw o-dimensional transient Lagrangian model which couples the thermal and deformation phenomena and is able to predict the temperature, strain rate, and strain distribution in the ship at any position in the roll bite. The interstand module incorporates semiempirical equations, deve loped in this study, which quantify the microstructural (percent recry stallization and recrystallized grain size) and textural changes in th e strip between the rolling stands. The intel-stand model also include s a temperature module to predict the through-thickness temperature di stribution in the strip based on one-dimensional heat conduction. Vali dation of the model against industrial data indicated that it gave rea sonable predictions for the temperature, grain size, and volume fracti on of some of the deformation texture components after recrystallizati on was completed. However, the model overestimated the mill loads in t he last stands for both the AA5182 and AA5052 alloys and underestimate d the amount of cube ({100}< uvw >) and S ({123}< 634 >) texture in th e recrystallized strip.