Abstract: A new expanding-extrusion complex forming process is put forward in accordance with weakness in forging of the retaining ring. Deforming regulation in the complex forming of the ring is analyzed by means of rigid-plastic FEM and physical modelling. The geometrical parameters of dies and the proportion of expanding and extrusion deformation are optimized. The FEM simulation is identical with the experiment results. The research indicates that the process has characteristics of well-distributed axisymmetric deforming, large shear deformation and complex deformation of compress and shear. So it can improve the current process and be used in production.

Key words: Complex forming, Expanding-extrusion, FEM, Retaining ring, Rigid-plastic