不同变形区组成下铝合金厚板蛇形轧制板曲率建模分析

Analytical Modeling of Plate Curvature in Snake Rolling of Heavy Aluminum Alloy with Different Deformation Zones

蛇形轧制作为一种新型的轧制工艺为高性能厚铝板生产提供了一种新方法,但是传统的异步轧制弯曲曲率模型不能用于蛇形轧制,蛇形轧制缺少精准的轧后曲率计算模型。根据变形区的特征及中性点的位置,确定了变形区组成及其存在边界条件;塑性变形区最多可分成4个区,对不同组成情况的变形区进行了分析,建立了各种情况下单位压力和上、下部分累积剪应变偏差模型,在此基础上建立了剪切应变引起的弯曲曲率模型,根据流动准则建立了轴向应变引起的弯曲曲率模型,最终建立了不同辊径比下的蛇形轧制的弯曲曲率模型。考虑到厚度方向变形的不均匀性,在建模过程中引入均匀系数E,使模型更加精确。采用Ansys模拟和实验数据进行了模型精度的间接验证。结果表明,与模拟和间接实验结果相比,最大和最小相对误差分别为10.71%和0.34%,证实了模型精度,可应用于弯曲曲率预测及控制;同时研究了不同工艺参数(偏移量、辊径比、压下量、工件初始厚度等)对弯曲曲率的影响规律。研究结果为厚规格铝板蛇形轧制生产提供重要理论和技术支持。

The snake rolling manufacture technique provides a new method for producing high-performance heavy aluminum plates.The traditional curvature model of the asymmetrical rolling cannot be simply applied to calculate the curvature of the snake rolling.The plate curvature model of the snake rolling was set up in this research according to the roll offset and different roll radii.The deformation region consists of four different zones at most which depends on the positions of the two neutral points,and this number may drop to three or two under other conditions.The deformation zone with different composition cases was analyzed,and the models of the specific pressure and the accumulated shear strain deviation between the upper and lower parts of the plate were established.The plate curvature caused by shear strain and axial strain was calculated separately.The homogeneity coefficient E was introduced during the plate curvature modeling process to ensure the model accuracy.Then the total plate curvature model was established.Ansys software simulation can well restore the snake rolling process,and the indirect experiments were also conducted to verify the precision of plate curvature theoretical model.The results show that the maximum and minimum relative error is 10.71%and 0.34%,respectively,compared to results of simulation method and the indirect experiments,indicating that the model can be applied for the online plate curvature control application with the effect of some self-learning methods.The plate curvature affecting law with different process parameters(roll offset,roll radius ratio,rolling reduction,and initial work piece thickness)was obtained.This research about the plate curvature modeling provides important references for the production of heavy aluminum plate snake rolling.