Abstract. Rotary forging with double symmetry rolls (DSRs) is a new
metal plastic forming technology developed on the basis of conventional
rotary forging with a single roll, which uses a pair of symmetrical cone rolls
to realize continuous local pressure plastic deformation of the workpiece.
Large-diameter, thin discs are a key component in nuclear power, aerospace,
deep-sea exploration, and other fields. At present, the forming process of
large-diameter discs mainly includes welding and multiple local upsetting,
but these processes exhibit many defects and can not meet the requirements
of industry. In this paper, a large diameter : thickness ratio disc is
integrally formed by rotary forging with DSRs. Using theoretical
calculation and finite element simulation methods, the stable rolling
conditions and calculation formulas of force and power parameters of rotary
forging with DSRs of a large diameter : thickness ratio disc are derived.
Based on the reliable three-dimensional rigid-plastic finite element model,
the plastic deformation characteristics of rotary forging with DSRs of discs
are studied, the reliability of the stable rolling conditions and the
calculation formulas of force and power parameters are verified, and the
defects and causes of unstable rolling conditions are analysed. An
experiment was carried out on a rotary forging press developed with double
symmetry rolls, and the experimental results are in good agreement with
simulation results, which demonstrated that rotary forging with DSRs is a
reliable technology for forming large diameter : thickness ratio discs. The
results of this research are helpful to promote the further development of
rotary forging with DSRs.