Prediction and Analysis of the Force and Shape Parameters in Variable Gauge Rolling

Abstract

Variable gauge rolling is a new process to obtain a plate for which the thickness changes continuously by continuously and dynamically adjusting the roll gap upward and downward in the rolling process. This technology is an effective method for producing lightweight, low-cost, and economical plates. However, variable gauge rolling is an unsteady process, and the changes in the force and deformation parameters are complex. In this research, based on the minimum energy theory of the variational principle and considering the characteristics of the roll movement and workpiece deformation comprehensively, the internal plastic deformation, friction, shear and tension powers, and the minimum result of the total power functional in upward and downward rolling are obtained with the first integral and then with a variation of adopting the specific plastic power and strain rate vector inner product. The analytical results of the deformation and force parameters are also established using the variational method. Then the precision of this model is certified using the measured values in a medium plate hot rolling plant and the experimental data for Tailor Rolled Blank rolling. Good agreement is found. Additionally, the variation rule of bite angle, neutral angle, and location neutral points are shown, and the change mechanism of the friction parameter on the stress state effect coefficient is given in variable gauge rolling. This research proposes a new mathematical model for rolling process control that provides a scientific basis and technical support for obtaining an accurate section shape in variable gauge rolling production.

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

“…Next, production data of thin strip steel from a large-scale company were utilized to analyze the effects of the friction coefficient, stress, tension before and after rolling, and roll-flattening radius on the rolling force. The following conclusions were drawn from the study: (1) The rolling force increases with an increase in the friction coefficient. When the friction coefficient exceeds a certain value, the rate of increase in the rolling force decreases.…”

“…The rolling force model forms the foundation for high-precision control of the rolling process and is the core component of the dynamic roll gap model. Therefore, researching a rolling force model which accurately reflects industrial production is an inherently valuable task [1,2].…”

Analysis of the Varying Thickness Rolling Process Based on the Principle of Pre-Displacement

“…Varying thickness rolling constitutes a process that facilitates the continuous alteration in the thickness of the exit cross-section of the rolled piece, in line with specific technological mandates [16]. Predicated on the progression of roll gap modifications, longitudinal varying thickness rolling may be bifurcated into two main types: thinning rolling and thickening rolling [17,18]. In the rolling process, the roll gap is gradually reduced, which is called thinning rolling, and the roll gap is gradually increased, which is called thickening rolling.…”