龙形轧制工艺参数对铝合金厚板心部剪切变形的影响

Effect of Dragon Rolling Parameters on Shear Deformation in Center of Aluminum Alloy Thick Plate

介绍了龙形轧制方法,运用大变形热力耦合有限元法分析了龙形轧制和对称轧制铝合金厚板变形区内轧件的变形情况,比较了龙形轧制和对称轧制条件下轧板不同位置剪切应变的分布情况,并研究了上下轧辊错位量、异速比、摩擦系数和压下量对轧板心部剪切变形的影响。结果表明:对称轧制中厚板心部的剪切应变几乎为0;龙形轧制中由于有"搓轧区"存在,厚板心部的剪切应变远远大于对称轧制,且心部的剪切应变随着轧辊错位量、异速比、摩擦系数和压下量的增大而增大。为了获得较大的剪切应变同时保证较小的弯曲曲率,在龙形轧制中应合理选择这些工艺参数。

The method of dragon rolling was introduced. The deformation condition of rolled piece in deformation zone of aluminum alloy thick plate during dragon rolling and symmetrical rolling was analyzed by using the elastic-plastic thermal-mechanical coupled FEM for large deformation. The distributions of shear strain in different positions of the plate during dragon rolling and symmetrical rolling were compared, and the effects of offset distance between upper and lower roll, the ratio of lower and upper roll speeds, the friction coefficient and the reduction on shear deformation in the center of the plate were studied. The results show that the shear strain in the center of the plate is almost zero during symmetrical rolling, while it is much larger during dragon rolling because of the existence of ＂rub zone＂. And the shear strain in the center of the plate increases with the increment of offset distance between upper and lower roll, the ratio of lower and upper roll speeds, the fi＇iction coefficient and the reduction. In order to obtain larger shear strain meanwhile ensure smaller bending curvature, those process parameters must be reasonably chosen in dragon rolling.