为研究大断面收缩率轴类件楔横轧成形问题,做了楔横轧一次楔成形极限实验.发现楔横轧一次楔轴向拉断成形极限可以远大于通常公认的75%界限,实验中成功轧制出断面收缩率为97.7%的超大断面收缩率轧件.推导了轧件轧制接触区轴向合力公式,利用有限元数值模拟方法分析了杆部对称截面轴向应力,揭示出楔横轧一次楔大断面收缩率可以成形的原因,即在适当条件下轧件变形接触区轴向受力接近于平衡,轧件杆部所受轴向拉应力较小所致.
To study the deformation of heavy section shrinkage cross wedge rolling, experiments with section shrinkages much larger than 75 %, which is usually regarded as the section shrinkage limit of single wedge in cross wedge rolling, were done. In the experiments, a work piece whose section shrinkage is 97.7 % was successfully rolled. A formula of resultant axial force on the contact zone of the work piece was deduced. Axial stress in the symmetrical section of the rod part was analyzed by the three-dimensional finite element method. The reason that the heavy section shrinkage can be rolled by single wedge is that under proper conditions the axial forces on the contact zone of the work piece are nearly in an equilibrium state, and thus the axial tensile stress on the rod part of the work-piece is reduced.