对镁合金板材轧制过程的热量变化方程进行推导,并用有限元方法分析此热力耦合过程,并对仿真结果进行实验验证。结果表明:板材在轧制过程中有较大的温度变化,轧制过程板料的温度变化主要是由变形产热、摩擦生热和板料-轧辊热传导、以及与环境的传热情况决定,并且受板和轧辊间温度差的影响;随着板温度的下降,轧制力和等效应力线性增加,最大轧制力是最小轧制力的3倍;当温度降到210℃,等效应力达到160 MPa时,板料出现边裂缺陷,达到轧制成型极限;板料较佳轧制温度应高于210℃。
The quantity change equation of heat during the rolling of magnesium alloy was derived,and the finite element method was used to analyze the thermal-mechanical process.The simulation results were proved by confirmatory experiments.The results show that,there is a great temperature change in the rolled sheet,and the temperature change depends upon the plastic deformation heat,friction heat and heat transfer between sheet and roller,sheet and environment.The temperature difference between the sheet and roller has some effects on the change.With the temperature decreasing,the rolling force and equivalent stress increase linearly,and the maximum rolling force is 3 times as the minimum rolling force.When the temperature drops to 210 ℃,the equivalent stress is 160 MPa,and the edge cracks are generated,which is the deformation limit of AZ31 magnesium rolling.The lowest temperature of AZ31 magnesium rolling without edge cracks is 210 ℃.