FEASIBLE SETUP DEFINITION AND ANALYTICAL STRAIN ESTIMATION FOR RADIAL-AXIAL RING ROLLING PROCESSES

In recent years, the radial-axial ring rolling process has assumed a growing importance in bulk deformation processes due to its low costs and high efficiency. Based on literature studies, and applying innovative concepts about feeding speed ranges, the paper details an efficient way to define feasible process parameters, both for FE simulations and real processes. Using a discretized representation of the ring by subdividing it into slices, the mathematical model estimates the geometry evolution of each slice during the whole ring rolling process, su-perseding previous averaged calculations and opening the way to a more detailed estimation of diameters, contact arc lengths, strains, stresses and forces. Based on the ring\u2019s estimated dimensions, the mathematical frame, suitable for cold, warm and hot processes, allows to derive the three strain components of the strain tensor, while filling the incompleteness of the literature where only the equivalent plastic strain was considered, and to estimate process forces, founded on the calculation of the flow stress of the material. The proposed analytical models have been applied to a wide range of rings with different ex-pansion profiles and dimensions ratio, and the relevant predictions have been compared with the results of FE simulations, showing a good reliability of the proposed approach