Simulation of hot rolling of magnesium strip by using finite element technique

Finite element thermal and mechanical models were developed to simulate the thermal and mechanical behaviour of magnesium strip during hot rolling. The commercial finite element software ADINA-TMC was applied to couple the mechanical and thermal components iteratively. A number of processes important rolling parameters such as the roll speed, the dynamic contact between the roll and the strip, deformation-induced heating, friction on the contact surfaces, heat transfer both inside and between the strip and the roll have been simulated. The temperatures and stresses of the magnesium strips and the load applied on the strip for different rolling schedules were predicted. Comparisons of the predicted and experimental exit temperatures have been conducted for the magnesium alloy AZ31 for different combinations of rolling temperatures, reductions and rolling speeds. The difference between the predicted and measured exit temperatures is less than 3% in most situations. The predicted and measured values of load applied on the magnesium strip agree reasonably for 14 passes conducted with two different rolling speeds. The numerical model is used as a basis to discuss some important issues in hot rolling, such as the contribution of plastic work to the temperature change, effect of reduction rate on the effective heat transfer coefficient between the strip and roll, and the presence of residual stresses.