20th International Forgemasters Meeting - IFM 2017

Ring rolling is an incremental bulk metal forming process for the production of seamless rings up to 10 m in outer diameter and up to 4 m in height. In ring rolling, the process layout is of high importance for the reduction of material waste and chipping. Simultaneously, waste due to product errors e.g. form errors, cracks and coarse grains has to be prevented. Nowadays, the waste due to form errors for rectangular cross-sections is of minor importance due to highly developed control systems of the ring rolling mills. However, the waste due to cracking and coarse grains is more relevant than ever, especially for highly loaded and safety critical applications, where the used materials are expensive and often challenging to roll. To prevent waste due to cracking, material allowances based on empirical knowledge are used, which usually lead to larger allowances than necessary. The finite element analysis can be used to improve the process layout of ring rolling processes by predicting geometrical evolution during the process and therefore reducing allowances. Furthermore, by the application of damage criteria during the simulation, predictions of damage evolution can be made. Also, by the application of microstructure calculation tools, microstructure evolution can be predicted. In this paper it is shown how the process layout can be improved by the use of the finite element analysis which ultimately can lead to waste reduction: During the simulation of the ring rolling process different damage criteria are calculated online by using a subroutine. Furthermore, the microstructure of the ring is modeled in a post processing step. Consequently, a process design with regard to microstructure and damage parameters could be possible. However, by the application of different damage parameters the strong dependency of the damage parameters of the load type is presented.