中文摘要：

针时内部多台阶并且精度尺寸要求高的半轴套管，本文提出了镦粗、反挤压杯形、冲孑L正挤压及扩孔整形的成形新工艺·并进行了实际生产。对新工艺开发过程中出现的圆角充不满、连皮无法完全冲出以及底部裂纹或折叠等缺陷产生的原因进行了分析．提出了相应的解决措施：通过增加2ram正挤压件上端尺寸，实现了圆角充满；利用有限元数值模拟确定了连皮冲不掉的原因，并通过提高反挤压工序的设备吨位解决了此问题；通过对挤压件设置追踪点反向追踪缺陷位置，完成裂纹缺陷的处理。

英文摘要：

A new process including upsetting, backward extrusion of cup-shaped, forward extrusion with piercing , reaming and sizing was proposed for axle sleeve that has multiple inner steps and high precision requirements, and the process had been used in real production. Furthermore, the reasons of defects, such as under filling of fillet, the situa- tion that the web could not be completely pierced and the crack appeared at the bottom during in the development of this novel process were analyzed. The corresponding solutions were put forward as follows. The fillet was fully filled by increasing 2 mm in length at the top of part. By using FEM the web could be completely pierced by improving press load of backward extrusion process. The crack defect location was founded by setting tracking points in the numerical simulation; therefore, the crack defect was completely resolved.