Use of finite element method for deeper analysis of rotary piercing

The method of finite elements is used for deeper analysis of two-roll rotary piercing with guide shoes. Two calculation models have been developed to gain better insight into the process: the extrapolation model and the reeling model. The reeling model allows better understanding of the stress conditions in the center of the billet, whereas the extrapolation model primarily serves to determine the functional relationships between the influencing factors and the forming parameters. Comprehensive experimental results obtained in a universal piercing mill were used for model verification and adaptation. Very good agreement has been found for the numerical and experimental values of the rolling force, rolling torque and shoe force. Furthermore, we found the redundant fraction of the total deformation to be very high in rotary piercing.