Research on an external adjustment method for RPECT roll profiles based on the segmented cooling principle

2021 ◽  
Vol 119 (1) ◽  
pp. 103
Author(s):  
Tingsong Yang ◽  
Yingwei Wang ◽  
Haijun Wang ◽  
Yang Hai ◽  
Fengshan Du
Keyword(s):  
Coupled Model ◽  
Temperature Gradients ◽  
Control Technology ◽  
Radial Temperature ◽  
Roll Profile ◽  
Adjustment Method ◽  
External Adjustment ◽  
Flatness Control ◽  
Electromagnetic Control ◽  
Flatness Defect

Roll profile electromagnetic control technology (RPECT) is a new strip flatness control technology that changes roll gap shape by controlling the roll profiles of electromagnetic control rolls (ECRs). To address the randomness of the flatness defect locations, this paper proposes an external adjustment method for RPECT roll profiles based on the segmented cooling principle. Based on the layout of the cooling areas and electromagnetic sticks, an electromagnetic-thermal-structural coupled model is established to analyse roll profile variations. The results show that symmetrically changing the cooling intensities of the different cooling areas can increase or decrease the roll crown of the ECR, while asymmetrically changing the cooling intensities of the different cooling areas can change the position of the maximum bulging point of the ECR. Variations in the component cooling ratio coefficient impact the effects of different cooling strategies, which needs to be considered when selecting the cooling strategy configuration scheme. Compared the maximum bulging values, radial temperature gradients and axial temperature gradients of different electromagnetic stick (ES) structures, the regulation law reverses when the length of the ES is too small, and the variation of the law is very small. Therefore, different ES structures have different segmented cooling regulation characteristics.

Research on roll profile electromagnetic control ability in optimal electromagnetic stick parameter

2021 ◽  
Vol 118 (3) ◽  
pp. 305
Author(s):  
Tingsong Yang ◽  
Jiayang Liu ◽  
Xinyi Ren ◽  
Yingwei Wang ◽  
Fengshan Du
Keyword(s):  
Effective Control ◽  
Control Element ◽  
Control Technology ◽  
Experimental Platform ◽  
Roll Profile ◽  
Strip Flatness ◽  
Flatness Control ◽  
Electromagnetic Control ◽  
Selection Of ◽  
Key Parameter

Roll profile electromagnetic control technology (RPECT) is a new strip flatness control technology. As the control element, electromagnetic sticks have a great effect on the control ability of RPECT. To improve control ability and extend service life, effective control ratio of electromagnetic stick is presented in this paper. The ratio is designed based on the structure character of electromagnetic stick, and can be used to evaluate the key parameter of electromagnetic stick. Based on the coupled FEM, the heat flux density of the roll inner hole and the temperature distribution of electromagnetic stick are analyzed for different effective control ratios; the average contact pressure between electromagnetic stick and electromagnetic control roll is studied to evaluate the change of force roll profile; the state of roll profile and the stress state of the roll are researched to analyze the comprehensive control ability. Through the verification on the roll profile electromagnetic control experimental platform, the reasonable selection range of effective control ratio, which can be used to expand the roll profile axial affected area, is from 0.5 to 0.583. In order to increase the roll crown, the selection of ηd needs to consider the current density and the optimal selection range of effective control ratio.

Analysis of the Thermal-force Roll Profile Control Ability Under Different Hole Structures and Slot Structures in the RPECT

2021 ◽  
Author(s):  
Tingsong Yang ◽  
Jiayang Liu ◽  
Haonan Zhou ◽  
Zhiqiang Xu ◽  
Fengshan Du
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Control Technology ◽  
Flexible Control ◽  
Roll Profile ◽  
Finite Element Software ◽  
Thermal Crown ◽  
Profile Control ◽  
Flatness Control ◽  
Electromagnetic Control

Abstract Roll profile electromagnetic control technology (RPECT) is a strip flatness control technology based on the flexible control of roll profiles. As the core component, electromagnetic sticks can bulge with the induction heating of induction coils. To ensure the integrity of the coil circuit, the surfaces of the electromagnetic sticks need to be provided with slots. Moreover, the inner hole of the electromagnetic control roll is also needed to install the electromagnetic stick in the roll. The structures of the inner hole and slots affect the local structure of the electromagnetic stick and the electromagnetic control roll and then change the roll profile control ability. To research the radial bulging ability, the roundness of bulging, and the composition between the thermal crown and force crown under different holes or slots, a finite element model of circumferential RPECT is established by using the finite element software MARC. After analysis, the results showed that the radial bulging ability and the roundness under the influence of the roll radius were larger than those under the influences of the slot radius and slot amount, and the composition characteristics of the comprehensive roll profile were different under different conditions. Therefore, to achieve accurate roll profile control, the influences of the structures of holes and slots need to be included in the RPECT index.

Experimental Validation and Numerical Simulation of Flexible and Micro-scale Roll Gap Control Technology

2021 ◽  
Author(s):  
Tingsong Yang ◽  
Qifa Chen ◽  
Yanfeng Feng ◽  
Yang Hai ◽  
Fengshan Du
Keyword(s):  
Large Diameter ◽  
Element Model ◽  
Control Technology ◽  
Micro Scale ◽  
Roll Profile ◽  
Profile Control ◽  
Flatness Control ◽  
Gap Control ◽  
Electromagnetic Control ◽  
Roll Gap

Abstract To obtain a better ability of strip flatness control, this paper proposes a new flexible and micro-scale roll gap control technology. According to the principle of roll profile electromagnetic control technology (RPECT), a new electromagnetic control rolling mill with the function of roll profile control and large diameter ratio rolling is designed and built. To analyze the flatness control ability of this mill, a comprehensive finite element model (FEM) is established and verified, which includes a FEM for predicting the electromagnetic control roll profile and a FEM of rolling process. The simulation results show that the crown control ability of RPECT is stronger than the quadratic crown control ability, and the effect of tension on the roll gap shape crown is small. The results in the indentation experiment and the rolling experiment show that increasing the roll crown of electromagnetic control roll can adjust the strip shape form edge wave to non-wave, and middle wave. The feasibility of using RPECT to adjust the roll gap shape has been verified, and the roll gap control goal of uniform transverse size distribution can be achieved.

Research on flexible roll profile electromagnetic control technology in precision rolling mill 

2018 ◽  
Vol 116 (1) ◽  
pp. 101
Author(s):  
Wenwen Liu ◽  
Yanfeng Feng ◽  
Tingsong Yang ◽  
Fengshan Du ◽  
Jingna Sun
Keyword(s):  
Induction Heating ◽  
Shape Control ◽  
Control Method ◽  
Control Technology ◽  
Computational Accuracy ◽  
Mechanical Coupling ◽  
Roll Profile ◽  
Strip Shape ◽  
Flexible Roll ◽  
Electromagnetic Control

To obtain a better strip shape control method, this paper proposes roll profile electromagnetic control technology (RPECT) based on induction heating technology and the principle of metal thermal expansion. Using the thermally driven and internal constraint mechanism of the electromagnetic stick, the technology innovatively converts the energy of induction heating into a thermodynamic hybrid power source, which achieves segmented micro-scale flexible roll profile adjustment and enhances the capacity for strip shape control. To research the technology, an electromagnetic control roll (ECR) with five control regions is built based on a ϕ560 × 2180 mm roll, and an electromagnetic-thermal-mechanical coupling model is established. Based on the model, the typical roll profile curves obtained by the ECR are researched, the strategy of increasing the growth rate of the roll crown is analysed, and the applications of RPECT in strip shape control and cold rolling are discussed. Finally, a roll profile electromagnetic control experiment platform is established to verify the model accuracy and feasibility of RPECT. The results show that RPECT can realize flexible roll profile adjustment and that the model has sufficiently high computational accuracy to research the roll profile of multi-segment RPECT.

An Advanced Strip Flatness Forecast and Simulation System for Hot Tandem Mill

2011 ◽  
Vol 291-294 ◽  
pp. 469-474
Author(s):  
Dong Cheng Wang ◽  
Hong Min Liu
Keyword(s):  
Rolling Force ◽  
Control Level ◽  
Simulation System ◽  
Control Technology ◽  
Independent Innovation ◽  
Development Platform ◽  
Strip Flatness ◽  
Technology Improvement ◽  
Flatness Control ◽  
Roll Shape

Taken hot tandem mill as research object, based on complete flatness control theary, in order to improve flatness control technology, an advanced strip flatness forecast and simulation system for hot tandem mill is developed through theoretical analysis, mathematical modeling, computer simulation and industrial validation. The simulation system’s outputs include flatness, on-load roll gap, rolling force distribution, contact pressure between rolls, strip’s temperature evolution, thermal roll shape and roll wear shape, which can be applied to mill type selection, flatness control performance analysis, preset control, roll shape optimization, virtual rolling, and so on. The simulation system can provide research and development platform for flatness control technology’ improvement and independent innovation, and has important significance to improve the flatness control level of hot tandem mill.

Modeling of Thermal Stresses and Thermal Cracking During Heating of Large Ingots

1996 ◽  
Vol 118 (2) ◽  
pp. 235-243 ◽  
Author(s):  
M. K. Alam ◽  
R. L. Goetz ◽  
S. L. Semiatin
Keyword(s):  
Thermal Stresses ◽  
Titanium Aluminides ◽  
Temperature Gradients ◽  
End Effects ◽  
Radial Temperature ◽  
Stress Criterion ◽  
Intermetallic Materials ◽  
Analytical Series ◽  
Biot Numbers ◽  
Selection Of

The development of temperature gradients and thermal stresses during the heating of large ingots has been investigated with special reference to the selection of heating schedules for brittle intermetallic materials such as titanium aluminides. A 1-D analytical (series) solution for radial temperature transients was used in conjunction with an elasticity analysis to determine the maximum thermal stresses that would be generated during ingot heating. The temperature gradients and stresses were seen to be strongly dependent on Fourier and Biot Numbers. In addition, finite element method simulations incorporating end effects and variations of thermal and elastic properties with temperature were performed and compared to the analytical results. Comparison of the predicated thermal stresses and actual ingot heating observations suggest that cracking is controlled by a maximum normal stress criterion.

A NUMERICAL INVESTIGATION OF THE FLOW IN A FULLY BLOCKED DIFFERENTIALLY HEATED ROTATING FLUID ANNULUS

1994 ◽  
Vol 05 (02) ◽  
pp. 203-206 ◽  
Author(s):  
Q.G. RAYER
Keyword(s):  
Computational Model ◽  
Horizontal Plane ◽  
Computer Modelling ◽  
Temperature Gradients ◽  
Rotating Fluid ◽  
Dynamical Equations ◽  
Radial Temperature ◽  
Rotation Rates ◽  
Horizontal Circulation ◽  
Simply Connected

A computational model has been used to determine the terms in the dynamical equations which are responsible for the formation of a certain horizontal circulation seen in a simply connected, differentially heated rotating fluid annulus. Experiments with a differentially heated rotating fluid annulus that is fully blocked by a thin, rigid, vertical radial barrier at rotation rates of up to 5 rad.sec−1 and with an externally applied radial temperature difference of 4 or 10 °C show two principal circulations. This paper is concerned with the mechanism for one of those circulations, which occurs in a horizontal plane. Computer modelling shows that this circulation is caused by small radial temperature gradients in the fluid, rather than centrifugal effects.

Influence of Roll Profile Configuration on High-Strength Strip Flatness Control Performance in Tandem Cold Rolling

2010 ◽  
Vol 145 ◽  
pp. 210-215 ◽  
Author(s):  
Jie Wen ◽  
Qing Dong Zhang ◽  
Xiao Feng Zhang ◽  
Xue Wei Ye
Keyword(s):  
Cold Rolling ◽  
High Strength ◽  
Industrial Applications ◽  
Fem Model ◽  
Roll Profile ◽  
Strip Flatness ◽  
Flatness Control ◽  
Pressure Peak ◽  
Tandem Cold Mill ◽  
Roll Gap

According to the characteristic of high-strength strip, the roll profile configuration and change of CVC tandem cold mill are analyzed. Through the establishment of FEM model, the influences of three representative forms of roll profile configuration on high-strength strip flatness control in CVC cold rolling mill are compared, which are conventional back-up roll / CVC intermediate roll, back-up roll with CVC compensation / CVC intermediate roll, VCL+ back-up roll / HVC intermediate roll. Compared with the other two roll profile configuration, the configuration of VCL+ back-up roll / HVC intermediate roll increases 26.74% in crown adjustment domain of roll gap and 22.09% in lateral stiffness of roll gap, decreases 27.43% in contact pressure peak values between rolls. The new roll profile configuration has obtained industrial applications. Production data indicate that the control accuracy of high-strength strip is improved, also the wear of back-up roll. Significant application results have been achieved.

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