极薄带最小可轧厚度研究新进展

Prospect for possible minimum foil thickness by rolling

最小可轧厚度是轧制理论中的一个经典问题,轧件厚度逐渐减小到接近一个极限,而不能再继续减薄。异步轧制引入了异速比的概念,轧件因上下表面摩擦力不同而产生搓轧作用,使金属更容易变形,此时是否还有最小可轧厚度需要进一步研究。实验发现,搓轧区比例是影响最小可轧厚度的关键参数,在此基础上推导了异步轧制条件下的最小可轧厚度新公式。并指出接近全搓轧时,最小可轧厚度可趋近于0;是否能达到,取决于轧制过程是否因裂纹、孔洞、褶皱等原因导致的断带而终止。

The minimum thickness of rolled foil is a classical question in rolling theory,the thickness of rolled foil gradually reduced to a certain limit,and cannot be reduced any more.Rolling speed ratio is a new concept which is introduced by asymmetric rolling,in which cross-shear effect occurred due to different friction force on upper and bottom surface.Plastic deformation is easier under the cross-shear effect.If minimum thickness limit still exist in this condition is worth further investigation.Cross-shear ratio was found to be the key parameter affecting minimum thickness.A new minimum thickness formula for asymmetric rolling was derived on the basis of these finds.It was indicated that the minimum thickness was approaching zero as cross-shear ratio was approaching 1.It could be achieved or not depended on whether the rolling process be stopped due to strip broken caused by defects such as crack,hole,gauffer etc.