scholarly journals Stability Analysis of a Nonlinear Coupled Vibration Model in a Tandem Cold Rolling Mill

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Xing Lu ◽  
Jie Sun ◽  
Guangtao Li ◽  
Zhenhua Wang ◽  
Dianhua Zhang
Keyword(s):  
Hopf Bifurcation ◽  
Cold Rolling ◽  
Rolling Mill ◽  
Vertical Direction ◽  
Rolling Process ◽  
Cold Rolling Mill ◽  
Mass System ◽  
Hopf Bifurcation Point ◽  
Tandem Cold Rolling ◽  
Vibration Model

Mill chatter in tandem cold rolling mill is a major rejection to the quality and production of the strips. In most mill vibration models, either the roll mass is usually limited to vibrate in vertical direction and vertical-horizontal directions, or the multiple rolls system is simplified to a single mass system. However, the torsional chatter is also a typical type of mill chatter, and the presence of intermediate roll and backup roll will affect the overall vibration of the mill structure system. In this paper, a newly cold rolling mill vibration model coupled with the dynamic rolling processing model and nonlinear vibration model is proposed with the consideration of dynamic coupling and nonlinear characteristics of the rolling process, multiroll equilibrium, and roll movement in both vertical-horizontal-torsional directions. By using Hopf bifurcation theorem and Routh–Hurwitz determinant, the existence of the Hopf bifurcation point of the mill vibration system and bifurcation characteristics are analyzed. At last, the influence of different rolling conditions on the stability of the coupled mill system is investigated, and these results can also be used to design an optimum rolling schedule and determine the appearance of mill chatter under certain rolling conditions.

scholarly journals Investigation and Optimization of Load Distribution for Tandem Cold Steel Strip Rolling Process

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 677 ◽  
Author(s):  
Xin Jin ◽  
Changsheng Li ◽  
Yu Wang ◽  
Xiaogang Li ◽  
Yongguang Xiang ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Cold Rolling ◽  
Prediction Model ◽  
Load Distribution ◽  
Rolling Mill ◽  
Fitness Function ◽  
Steel Strip ◽  
Rolling Process ◽  
Cold Rolling Mill ◽  
Tandem Cold Rolling

In order to improve the cold rolled steel strip flatness, the load distribution of the tandem cold rolling process is subject to investigation and optimization. The strip deformation resistance model is corrected by an artificial neural network that is trained with the actual measured data of 4500 strip coils. Based on the model, a flatness prediction model of strip steel is established in a five-stand tandem cold rolling mill, and the precision of the flatness prediction model is verified by rolling experiment data. To analyze the effect of load distribution on flatness, the flatness of stand 4 is calculated to be 7.4 IU, 10.6 IU, and 16.8 IU under three typical load distribution modes. A genetic algorithm based on the excellent flatness is proposed to optimize the load distribution further. In the genetic algorithm, the classification of flatness of stand 4 calculated by the developed flatness prediction model is taken as the fitness function, with the optimal reduction of 28.6%, 34.6%, 27.3%, and 18.6% proposed for stands 1, 2, 3, and 4, respectively. The optimal solution is applied to a 1740 mm tandem cold rolling mill, which reduce the flatness classification from 10.8 IU to 3.2 IU for a 1-mm thick steel strip.

Thickness Indirect Measurement Method for Direct Pulling Pilot Cold Rolling Mill

2011 ◽  
Vol 189-193 ◽  
pp. 2670-2674
Author(s):  
Zhi Jie Jiao ◽  
Chun Yu He ◽  
Jian Ping Li ◽  
Xiang Hua Liu
Keyword(s):  
Cold Rolling ◽  
Rolling Mill ◽  
Measurement Method ◽  
Rolling Process ◽  
Indirect Measurement ◽  
Cold Rolling Mill ◽  
Movement Data ◽  
Program Flow ◽  
New Type ◽  
Exit Speed

Pilot cold rolling mill is the important tool for the cold rolling process researching and new steel grade development. According to the design of the new type direct pulling pilot cold rolling mill, based on the mass flow constant principle, strip exit thickness indirect measurement method is studied. During rolling, strip entry and exit speed can be calculated accurately according to the measured value of two sides’ clamps movement. Data filtering treatment is adopted and program flow chart is designed. Based on the material entry thickness measured manually, exit thickness of all passes can be measured indirectly. This thickness indirect measurement method has been applied successfully on the new type pilot cold rolling mill, and the measurement results show that this method has a good accuracy.

Target Curve Setting Model for Automatic Flatness Control on Stand 5 of 2180 mm Tandem Cold Rolling Mill

2014 ◽  
Vol 665 ◽  
pp. 37-41 ◽  
Author(s):  
Guang Hui Yang ◽  
Jian Guo Cao ◽  
Jie Zhang ◽  
Hong Bo Li ◽  
Jie Zheng
Keyword(s):  
Cold Rolling ◽  
Temperature Stress ◽  
Rolling Mill ◽  
Cold Rolling Mill ◽  
Tandem Cold Rolling ◽  
Temperature Distributions ◽  
Strip Shape ◽  
Flatness Control ◽  
Transverse Temperature ◽  
Stress Compensation

Based on the theory of target curve, a method of improving flatness target curve is proposed. The transverse temperature distributions of strip are measured and described with a biquadratic expression, and the statistics method is used to analyze the temperature distributions. Finally, the additional temperature stress compensation is calculated to improve the strip shape.

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

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 401
Author(s):  
Hainan He ◽  
Jian Shao ◽  
Xiaochen Wang ◽  
Quan Yang ◽  
Xiawei Feng
Keyword(s):  
Cold Rolling ◽  
Rolling Mill ◽  
Steel Strip ◽  
Work Roll ◽  
Rolling Process ◽  
Silicon Steel ◽  
Cold Rolling Mill ◽  
Strip Profile ◽  
Profile Control ◽  
Small Work

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.

The Integrated Robust Control of Interstand Strip Tension for Tandem Cold Rolling Mill

2010 ◽  
Vol 145 ◽  
pp. 230-237 ◽  
Author(s):  
Xiao Feng Zhang ◽  
Qing Dong Zhang ◽  
Meng Yu ◽  
Kang Jian Wang ◽  
Pei Jie Huang
Keyword(s):  
Cold Rolling ◽  
Rolling Mill ◽  
Controller Design ◽  
Integrated Control ◽  
Cold Rolling Mill ◽  
Tandem Cold Rolling ◽  
Synthesis Design ◽  
Tandem Cold Mill ◽  
Strip Quality ◽  
Cold Mill

We describe an integrated tension controller design for a tandem cold rolling mill in steel plants. To achieve stable rolling and ensure strip quality, it is very important to control the tension of the cold rolling mill. Previous researches examined only the operation of a single stand. But it is not sufficient to examine the operation and effect of whole stands because the operation is wholly interdependent. To solve the problem, this paper proposes an integrated control strategy for tension control of tandem cold mill, the full stand model for the tension system of a tandem cold mill is built, and the interaction of all the stands is analyzed. Then applying the method of μ-synthesis design a integrated robust tension controller. Simulation with the practical data proves the integrated robust tension controller can achieve more robust performance than that of typical industrial approach.

Study on the Shifting Model of Edge Drop Control in Ultra-Wide 6-High Tandem Cold Rolling Mill

2012 ◽  
Vol 452-453 ◽  
pp. 1257-1261 ◽  
Author(s):  
Jian Guo Cao ◽  
Yan Lin Wang ◽  
Hong Bo Li ◽  
Mu Qing Song ◽  
Sheng Hui Jia ◽  
...  
Keyword(s):  
Finite Element ◽  
Cold Rolling ◽  
Rolling Mill ◽  
Work Roll ◽  
Cold Rolling Mill ◽  
Tandem Cold Rolling ◽  
Cold Rolling Mills ◽  
Important Quality ◽  
Control Work ◽  
Edge Drop

Edge drop is an important quality evaluating index for strip cross-section with the increasing of requirement for higher gauge accuracy to meet customer's demand. The mathematical model of roll shifting system plays an important role in controlling the edge drop on modern tandem cold rolling mills. Based on the explicit dynamic finite element method, a 3D finite element simulation model of rolls and strip is established for a large ultra-wide 6-high cold rolling mill with the developed EDW (edge drop control work roll) and the matched CVC intermediate roll to investigate the effect of work roll shift on edge drop of strip. Considering on the characteristics of EDW work rolls, equivalent area compensated method has been put forward to build the shifting model for edge drop control. The results indicated that the values of edge drop are less than 7μm by using the proper shifting model and the shifting model can be used to guide the practical production.

Sign in / Sign up

Export Citation Format

Share Document