Theory and numerical simulation of minimum rolling thickness for thin strip rolling
LIU Xiao1,2,3, FU Lun1, LU Yue-feng1, WANG Tao2,3, XIAO Hong1
1. National Engineering Research Center for Equipment and Technology of Cold Strip Rolling, Yanshan University, Qinhuangdao 066004, Hebei, China; 2. College of Mechanical and Vehicle Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China; 3. Engineering Research Center of Advanced Metal Composites Forming Technology and Equipment, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China
Abstract：With the miniaturization and integration development of the Intelligent manufacturing,electronic communication,and other industries,it is required to improve the product quality of precision rolled strips,especially for the control accuracy of the thickness. Therefore,the theoretical research on the contact deformation zone in the rolling process of the precision strip is of great significance. The Stone rolling force model as the classic model of conventional cold rolling theory of thin strip assumes that the roll maintains a circular profile in the contact deformation zone. And the average unit pressure is obtained by solving the contact arc length with the Hitchcock formula. On this basis,the Stone theory of the minimum rolling thickness is established. In the experiment and actual production,many scholars found that the calculated value of the Stone rolling force is far from the actual value sometimes. This is because there is a neutral zone in the contact deformation zone under some rolling conditions and the assumption of the circular roll shape is no longer applicable. The existence of the neutral zone increases the rolling force prominently,but the extension deformation of strip metal is very little,that is,the rolling difficulty increases,and the rolling efficiency decreases. The finite element method is used to analyze the rolling process of the thin strip with different thicknesses. The variation rules of the profile of the contact deformation zone and the distribution of contact pressure under different reductions are obtained. The smaller the initial thickness of the strip or the greater the single-pass reduction,the larger the proportion of the neutral zone in the contact deformation zone,and the contact pressure distribution tends to parabolic distribution. Based on the Stone rolling force formula,the minimum rolling thickness model of thin strips with rolling efficiency consideration is established. For the ratio of the initial thickness to the Stone minimum rolling thickness,the critical pass reduction can be calculated when the contact deformation zone is without neutral zone according to the rolling process parameters by this model. The range of high-efficiency rolling thickness and the applicable conditions of the Stone rolling force model can be determined based on the critical single-pass reduction,which provides theoretical guidance for the production process of precision thin strip rolling.
刘晓, 付伦, 芦跃峰, 王涛, 肖宏. 薄带材轧制的最小可轧厚度理论及数值模拟[J]. 钢铁, 2021, 56(11): 87-95.
LIU Xiao, FU Lun, LU Yue-feng, WANG Tao, XIAO Hong. Theory and numerical simulation of minimum rolling thickness for thin strip rolling[J]. Iron and Steel, 2021, 56(11): 87-95.
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2021, Vol. 56 
