Establishment and Numerical Analysis of Rolling Force Model Based on Dynamic Roll Gap

Abstract

Applying mathematical models and numerical methods is crucial for describing and simulating the metal cold-rolling process, wherein the accurate prediction of rolling force is an effective way to improve the quality of rolled sheets. This paper considers key influencing parameters such as friction lubrication, stress, tension, and roll-flattening radius during the rolling process and establishes a calculation model for the friction coefficient and roll-flattening radius. By considering the coupling effect of the dynamic roll gap on rolling force, a rolling force model for non-steady-state friction lubrication during the rolling process is obtained. The correctness of the proposed model is verified by comparing it with industrial measurement results. The influences of the friction coefficient, stress, tension before and after rolling, and roll-flattening radius on rolling force are quantitatively studied. The results show that the rolling force increases with an increase in the friction coefficient. When the friction coefficient exceeds 0.2, the rate of increase slows down, approaching dry friction conditions. The rolling force increases linearly with stress but decreases with increasing tension before and after rolling. The rolling force model, considering the roll-flattening radius, provides numerical calculation results that are closer to an industrial measured rolling force. This work contributes to a better understanding of the mechanism behind the improvement of the cold rolling process.

Influence of Rolling Speed on the Temperature Field During Cold Rolling of Aluminium Sheets

“…The stored deformation energy remains in the material after unloading in the form of internal defects, phase changes and other permanent microstructural changes [6][7][8][9][10], while the generated heat causes an increase in the material temperature [11]. In the rolling process, in addition to the heat generated during plastic deformation, there is also a heat flux resulting from the friction process that occurs in the contact area between the tool and the deformed material [12][13][14][15]. The results of the numerical modelling of the rolling process [12] indicate that the increase in the temperature of the rolled strip as a result of the heat released both due to plastic deformation and friction forces increases slowly at the front of the deformation zone and increases its intensity along the path of contact with the surface of the rolls.…”