【摘要】 本文运用平面应变剪切压缩模型导出了异步冷轧轧制力的近似上界解和全面考虑轧辊与轧件弹性变形的计算机辅助下界解,阐明了异步轧制降低冷轧压力的机理并给出了可供工程分析、计算之用的理论公式。本解的分析表明,异步冷轧的降力作用随两工作辊的差速比 i,摩擦系数μ及辊径与轧件厚度之比 R/h₀ 值的增加而愈趋显著。比较理论计算结果与作者的实验数据,证明二者符合情况良好。本文还藉助计算机对“搓轧”区内的单位压力分布特征进行了分析,讨论了前人理论中的问题,并证明了本文所用下界解压力模型的正确性。更多还原

【Abstract】 Many sections of the rolling industry have an interest in the reported possibility of making significant reductions in the rolling load in cold strip rolling by employing work rolls driven at different speeds.The present work attempts to link practical observations and experiences with theory so that more insight can be gained on the mechanism by which the rolling load is reduced and the way some factors affect the process. On the basis of a plane strain compression model,an approximate upper bound solution is proposed together with the numerical solution of the force reduction ratio, Q, based on an approximate analysis of the lower bound type. The latter takes the elastic deformation of the work rolls and the strip into consideration. The results show that the load reduction effect during cross shear rolling can be related to a change in power balance and in the prevailing state of stress. The analytical solutions and numerical calculations are compared with the experimental results obtained by the author and it is found that they are in good qualitative agreement. The effect of rolling force reduction is affected by such parameters as the coefficient of friction μ, the pass reduction r, the roll speed mismatch ratio i and the ratio R/h0(roll radius/thickness). Within certain constraints,a quantitative prediction of Q can also be made by using the proposed models.The present work also attempts to establish the roll pressure distribution characteristics within the cross shear zone via computer-aided numerical solutions for the equilibrium differential equations based on a variable yield stress and a mean yield stress .The results show that Sachs and Klinger’s theory predicts too high a pressure rise and that a straight line pressure distribution pattern may be introdued as a reasonable simplification to facilitate roll force calculations. The solutions also indicate that the difference between the specific roll forces S1 and S2 is immaterial from the point of view of engineering calculations. All the experimental and theoretical work was done in the George Alexander Laboratories of the University of Aston, Birmingham, under the supervision of Professor D. H. Sansome.更多还原