A new model for thermo-mechanical coupled analysis of hot rolling

A new sine velocity field is proposed to analyze total power in the roll gap for rolling in hot strip finishing mill. The field and linear geometric midline yield criteria are used to calculate the plastic deformation power, and the collinear vector inner product method is used to get friction power. Then analytical equation of strip rolling power functional is obtained. Finally, the roll force and torque can be calculated by minimizing the power functional. In the model, average deformation resistance is determined by the thermo-mechanical coupled analysis. The prediction accuracy of the proposed model is examined through comparing with the on-line measured results in a hot strip finishing mill. It shows that the predicted roll forces are in good agreement with the measured ones, and the maximum error is less than 12 %. Moreover, the effects of various rolling conditions, such as thickness reduction, friction factor, and shape factor, on roll force, location of neutral angle, and stress-state coefficient are discussed systematically.