Modification of Roll Flattening Analytical Model Based on the Plane Assumption

et al. 2022

Chin. J. Mech. Eng.

Self Cite

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.

Section: Open Accessmentioning

confidence: 99%

“…Therefore, the mean value of cos α obtained with the integral mean value theorem is The internal plastic deformation power Ẇui is finally obtained as (8)…”

Section: Internal Plastic Deformation Powermentioning

confidence: 99%

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

Liu

et al. 2022

Chin. J. Mech. Eng.

Self Cite

“…A boundary integral method is commonly used to analyze the deformation of the roll system and obtain reliable results [15]. Pawelski et al [16] proposed a mathematical model of load distribution along the width of the strip, and Wang et al [17] used this method and gave a calculation model of roll flattening deformation based on the plane hypothesis principle. Similarly, a similar model was designed to solve the rolling of an ultra-thin strip, where a pair of work rolls may contact outside the strip area after rolling deformation [18].…”

Section: Of 15mentioning

confidence: 99%

Silicon Steel Strip Profile Control Technology for Six-High Cold Rolling Mill with Small Work Roll Radius

Shao

et al. 2020

Metals

Due to the requirement of magnetic properties of silicon steel sheets, producing high-precision size strips is the main aim of the cold rolling industry. The tapered work roll shifting technique of the six-high cold rolling mill is effective in reducing the difference in transverse thickness of the strip edge, but the effective area is limited, especially for a high crown strip after the hot rolling process. The six-high mill with a small work roll size can produce a strip with higher strength and lower thickness under a smaller rolling load. At the same time, the profile of the strip can be substantially improved. By advancing a well-established analytical method, a series of simulation analyses are conducted to reveal the effectiveness of a small work roll radius for the strip profile in the six-high cold rolling process. Through the analysis of flattening deformation and deflection deformation on the load, the change rule of the strip profile produced by the work roll with a small roll diameter can be obtained. Combined with theoretical analysis and industrial experiments, it can be found that the improvement effect of the small work roll radius on the profile of the silicon strip is as significant.

“…Abdelkhalek et al [ 16 ] put forward a prediction model of shape defects in the sheet rolling by describing the coupling method of bite plastic deformation and post‐bite buckling deformation. Wang et al [ 17 ] proposed a new rolling model based on elastic half‐plane theory by introducing a transition coefficient. Although the shape mechanism model is significant, it is difficult to precisely control the strip shape due to the assumption and coupling of various factors in the practical rolling process.…”

Section: Introductionmentioning

confidence: 99%

The Prediction Model for Transverse Thickness Difference of Electric Steel in 6‐High Cold Rolling Mills Based on GA‐PSO‐SVR Approach

Song

Cao

et al. 2022

steel research int.

To meet the shape quality requirements of “Dead flat” rectangular section of electrical steel in the cold rolling process, the transverse thickness difference (TTD) prediction model of 6‐high tandem cold rolling mills (TCMs) based on genetic algorithm, particle swarm optimization, and support vector regression (GA‐PSO‐SVR) is proposed. The TTD prediction model uses 5000 coils of data obtained from a cold rolling line. The GA‐PSO‐SVR model is obtained by the GA‐PSO hybrid algorithm to search and obtain the optimal parameter of the SVR to improve the prediction model accuracy. The results reveal that using multiple evaluation indicators the GA‐PSO‐SVR model has preferably adaptability and higher accuracy. Meanwhile, the relative importance of input variables is calculated based on the GA‐PSO‐SVR model, which indicates that the shape control methods in stands 1–5 have the most important influence on the TTD. The TTD prediction model is continuously applied to 1420 mm 6‐high TCMs; the results show that the rate of the TTD less than 7 μm increased from 29.6% to 63.85%.