The production of seamless tubes by planetary cross rolling is a very complex metal forming process. During this process, four rolls rotate around their own axes and as a whole around the axis of the rolling stock. The inclination, the offset and
geometry of the rolls characterize this cross-rolling process and influence the rolling speed and geometry of the rolled tube. The thick-walled hollows of steel or copper are elongated with a high reduction of the wall thickness.
The purpose of the FEM simulation is to achieve a deeper process understanding by analyzing physical interrelationships of the planetary cross rolling process and to solve open questions. The basic prerequisite for these simulations is a model which characterizes this process realistically. Particularly, a realistic representation of the geometry and kinematics of the rollers and the mandrel, an adequate description of the material behavior, as well as the friction and thermal conditions, are of great importance.
This paper describes the development of the model with the simulation tool FORGE, some important simulation results and a detailed evaluation of the material flow.
One of the most important factors of each simulation is the material model. The conventional material model for steel was not suitable for this high speed process.
Therefore, a new advanced material model regarding the high strain and strain rate was established to analyze the material flow in this complicated forming process with high accuracy.
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22-23 October 2012 Pacengo del Garda 
