Modelling of AA6082 Ductile Damage Evolution under Hot Rolling Conditions

Formability is one of the critical issues in metal forming processes since it is a limiting factor for the process parameters choice as well as for the attainable part quality. This issue is of even higher importance in processes carried out at elevated temperature, in which more variables are involved, and the temperature changes can influence the material microstructural behavior, which, in turn, influences the fracture occurrence. The work reported in the paper refers to the hot cross wedge rolling process carried out on AA6082 aluminum alloy bars, which was taken as the reference industrial case. A modification of the Oyane fracture criterion providing the dependency on the temperature and strain rate was developed and calibrated by means of hot tensile tests, which were carried out at varying temperature and strain rate spanning the hot temperature range for the given alloy. Material formability changes were identified and modelled. The calibrated fracture criterion was implemented in the FE model of the industrial process and validated by comparing the numerical and experimental outcomes.