Modeling and Simulation of the Rotary Piercing Process

Finite element modeling is utilized successfully to optimize complex metal forming processes including the rotary piercing process. The rotary piercing is the first forming process for the production of seamless tubes from round billets using two rotating barrel type rolls, which are inclined to the roll axis, a plug and Diescher Discs. In this work, a three-dimensional finite element model of the piercing process in the skew rolling mill using the implicit commercial code Forge2007 was developed to predict the geometry and deformation behavior during the piercing process. Different friction models are employed to obtain correct friction conditions between the rolls and the billet. Experiments of industrial scale are used to validate the finite element model. The results showed that the model is able to predict the average outer diameter, the average inner diameter and the wall thickness very well. Furthermore, the viscoplastic friction law was more flexible to achieve accurate friction conditions between the rolls and the billet.