Numerical and analytical approaches for improving die design in the radial forging process of tubes without a mandrel

Radial forging without a mandrel offers a cost effective method for production of tubular components. however, nonuniform deformation, thickness variation, poor surface quality and undesirable residual stress distribution are problems that need to be overcome in order to achieve an optimal process. in this paper, radial forging dies with curved-shape profiles are proposed to alleviate some of the mentioned difficulties. finite element simulations are used to prove the advantage of the proposed dies over conventional linear dies. a novel analytical approach, based on the slab method of analysis, is developed to verify the finite element modeling. the obtained results provide useful guidelines for design and optimization of the radial forging process without a mandrel.