Numerical Simulation On Microstructural Evolution During Hot Rolling Of 3104 Aluminum Alloy

3X04(3004,3104 and 3204) aluminum alloy are the main materials for pop cans, and belong to the A1-Mn-Mg series that can not be strengthened by heat treatments. It's rules of cogging and finishing rolling play a great important role on the sheets for pop cans. Tests were performed to study the microstructure evolution during hot rolling of 3104 aluminum alloy by combining hot deformation simulation and numerical simulation.The hot compression deformation tests of 3104 aluminum alloy at elevated temperature were performed on Gleeble-1500 system, with the deformation temperature ranged from 300℃to 500℃and strain rates from 0.01 s-1 to 20 s-1. Results show that the flow stress of 3104 aluminum alloy increases with strain increasing and tends to constant after a peak value at lower strain rate(≤1s-1), showing dynamic recover. The flow stress fluctuates in sawtooth and decreases after a peak value with strain increasing at higher strain rate(≥10s-1), showing discontinuous dynamic recrystallization. Constitutive analysis suggestes that the peak stress can be represented by a Zener-Hollomon parameter in the hyperbolic-sine-type equation, with the hot deformation activation energy of 215 kJ/mol. Relative errors between calculated peak stress and measured peak stress are all within±10%.The recrystallization kinetic model on hot rolling of 3104 aluminum alloy was set up by isothermal interrupted hot compression tests in 400℃and 500℃at the strain rates of 0.01 s-1 and 0.1 s-1 with delay times varying between 30 and 120. It is indicated that the static softening increases with increasing deformation temperature and holding temperature and delay times, static recrystallization happens easily while it is hold at elevated temperature. So not only the parameters during deformation but also the parameters during passes need accurating control for the recrystallization control during multistage hot rolling of 3104 aluminum alloy.The reasonable boundary conditions on each pass during hot rolling were studied by plastic finite element method according to the data measured in factory during the multi-pass hot rolling of 1100 aluminum alloy. It shows that the temperature of workpieces is affected mainly by heat transfer coefficient, and the affection from friction factor to temperature of workpieces can be neglected when the velocity of workpieces reached 90% of the linear velocity of rollers. The quantitative relationship between heat transfer coefficient and contact pressure was also given in this paper. By importing the constitutive model, recrystallization kinetic model and boundary conditions, and by re-programming on DEFORM software, it was realized to make a heat-force-microstructure simulation on the multi-pass hot rolling of 3104 aluminum alloy. The simulation results show that during multi-pass hot rolling, the distribution of recrystallization percent is not uniform along the thickness, which is caused by disuniform deformation because of the effect of friction and figure factor of deformation zone. Recrystallization activity is observed obviously near the surface of the workpiece on the front passes because of big deformation, while it is observed obviously in the center and impenetrates the whole thickness of the workpiece as pass increasing.