Roll forming method for cobalt-based superalloy thick-wall ring forgings

The invention discloses a roll forming method for cobalt-based superalloy thick-wall ring forgings. The roll forming method comprises the following steps: designing an intermediate billet into specially-shaped ring billets each of which is provided with a lug boss close to the inner wall; calculating the size of each specially-shaped billet according to an isovolumetric principle; designing a special die according to the shape and size of each specially-shaped ring billet; heating a cobalt-based superalloy rod to a deformation temperature, carrying out upsetting, punching and pre-rolling, and then manufacturing the cobalt-based superalloy rod into specially-shaped ring billets under the action of the special dies; heating the specially-shaped ring billets to the deformation temperature again, and rolling the specially-shaped ring billets into the thick-wall ring forgings by matching with appropriate rolling parameters. According to the method disclosed by the invention, the defects of grooves, folding and the like occurring in the thick-wall ring forging rolling process can be effectively overcome, and the rolling quality of the thick-wall ring forgings can be improved. The roll forming method can be used for roll forming of the thick-wall ring forgings.