AZ31镁合金中厚板轧制温度场的数值模拟与实验验证

Numerical Simulation and Experimental Verification of Temperature Field in Medium Plate Rolling of AZ31 Magnesium Alloy

通过数值模拟分析了AZ31镁合金中厚板在轧制变形区的温度分布,建立了轧后镁板平均温度关于轧辊温度、轧制速度、轧制压下量、板材厚度的经验公式,并辅以相应的实验验证。结果表明:当镁板较薄、轧制速度较小时,镁板中心层的塑性变形热在轧制变形区向表层传递,中心层的温升不能代表镁板塑性变性产生的温升;轧后镁板的平均温度与轧辊温度、轧制速度、轧制压下量正相关,与板材厚度反相关;轧后镁板平均温度的计算值与实验值的最大相对误差为8.34%,平均相对误差为7.4%,经验公式能很好的预测轧后镁板的平均温度。经验公式的提出,利于实现“AZ31镁合金板材的等温轧制”控制;对镁合金轧制工艺制度的合理制定以及后续轧制设备的选择有重要指导意义。

The temperature distribution of the AZ31 magnesium alloy in the rolling deformation zone was analyzed by numerical simulation. The empirical formula of the average temperature of the magnesium plate after rolling with respect to the roll temperature, the rolling velocities, the rolling reduction rate, and the thickness of the plate were established and supplemented with corresponding experimental verification. The results show that when the magnesium plate is thin and the rolling velocity is small, the plastic deformation heat of the center layer of the magnesium plate is transferred to the surface in the rolling deformation zone. The temperatur e rise of the center layer cannot represent the temperature rise caused by the deformation of the magnesium plate. The average temperature of the magnesium plate after rolling is positively related to the roll temperature, rolling velocity and rolling reduction rate, and is inversely related to the sheet thickness. The maximum relative error between the calculated and experimental values of the formula is 8.34%, and the average relative error is 7.4%. The formula can well predict the average temperature of the magnesium plate after rolling. The proposed empirical formula for magnesium plate temperature prediction is conducive to the realization of "isothermal rolling" control of AZ31 magnesium alloy sheet;it has important guiding significance for the reasonable formulation of magnesium alloy rolling process system and the selection of subsequent rolling equipment.