20th International Forgemasters Meeting - IFM 2017

The hot ring rolling process with as-forged ring-shaped billets is designed conventionally for forming the accurate size and configuration of all kinds of ring components. However, when the ring-shaped billet is prepared by casting, the hot ring rolling process have be designed not only to form the accurate size and shape of ring parts but also to transform as-cast microstructures into the as-forged at the same time to meet the final microstructure and mechanical property requirements of rings, especially for large rings. In this investigation, an as-cast ring-shaped billet of 42CrMo was prepared and its microstructure and mechanical properties were tested firstly. Then, the hot ring rolling process with an as-cast ring-shaped billet was designed by analyzing the hot deformation behavior and microstructure evolution of as-cast 42CrMo by thermo-mechanical experiments and microstructure examination, and simulated by DEFORM software. Finally, the hot ring rolling process with the as-cast ring-shaped billet was carried out and its microstructure and mechanical properties were examined. The results show that the designed ring rolling process for the as-cast ring-shaped billet can improve casting structures mainly including removing casting pores and porosity defects and refining casting coarse grains. The microstructure and mechanical properties of the ring manufactured by the designed ring rolling process for the as-cast ring-shaped billet can meet the requirements of ring parts. Keywords: Large rings; Hot ring rolling; Simulation; Microstructure; Mechanical properties