Thanks to EU funding, the RORC (Rolled-only IN718 ring-shaped components) project developed and successfully validated a robust and reliable ring-rolling-only route for manufacturing nickel-based alloy (IN718) low-pressure turbine (LPT) disk. Project partners began by developing an advanced predictive ring-rolling modelling tool. They carried out laboratory experiments to describe the alloy's behaviour in conditions that reproduce real ring-rolling operation sequences. The RORC team produced five full-size rings by rolling alone. It then tested them with geometrically similar close-die forged rings to establish the competitiveness of the new process route. Results show the potential and limitations of current ring-rolling technology and provide evidence for its further advancement. Researchers demonstrated the processing of IN718 turbine disks solely by ring-rolling with properties that are comparable to those of disks obtained from current close-die forging manufacturing technology. This will lead to more efficient raw material use and lower manufacturing costs. They also gained know-how and new engineering knowledge which will enable them to propose design modifications for current mills capable of rolling valid disks well beyond the capabilities of even the largest available mills. This will help to cope with the requirements of future large diameter turbo engines according to existing trends. RORC presented a rolling-only process for aero engine turbine disks by eliminating the close-die forging step and its required tools from the process. This should result in notable economic gains. The project will also boost competitiveness by enabling the EU to manufacture LPT discs directly from ring-rolling-only technology, thus reducing their cost while increasing the number of potential suppliers compared to conventional close-die manufacturing.
RORC, IN718 ring-shaped components, low-pressure turbine disks, ring-rolling-only technology