ADVANCED ROLL BITE MODELS FOR COLD AND TEMPER ROLLING PROCESSES

This paper presents a fast and robust roll bite model for cold and temper rolling processes including mixed lubrication model (lubricant, surface asperity deformation) and non-circular roll profile. Firstly, the existing roll bite models are reviewed in details to understand their physics, their specificities, their differences and their resolution strategies, with a particular focus on strategies allowing for short computing time (CPU) even for heavily deformed non circular roll profiles. From this preliminary analysis, some existing strategies are selected to develop a new roll bite model. This new model includes in particular roll circumferential displacements for roll profile calculation, an efficient relaxation technique that updates the relaxation factor dynamically at each iteration to solve the roll-strip coupling. The resulting computing time is generally less than one second (on a single processor) and convergence is certain for all types of cold and temper rolling conditions (dry contact): from tandem mill heavy reductions to double reduction and very light reduction temper rolling (< 0.5%). Simulation results are also discussed against a reference finite element (FE) rolling software. Finally, it is illustrated how this new roll bite model can be used on industrial database to develop accurate presets of roll force for temper mills.