Calculation and Analysis of Tandem Cold Rolling Force Parameters

2014 ◽  
Vol 1004-1005 ◽  
pp. 1109-1113
Author(s):  
Jin Lan Bai ◽  
Hong Zhi Pan
Keyword(s):  
Tensile Stress ◽  
Cold Rolling ◽  
Rolling Force ◽  
Measured Data ◽  
Strip Flatness ◽  
Tandem Cold Rolling ◽  
Thermal Crown ◽  
Flatness Control ◽  
Arc Lengths ◽  
Contact Arc

In order to improve the accuracy of rolling force parameters,the elastic deformation and pressure between rolls of tandem cold rolling are calculated using divided element method in this paper. Bland-Ford model is used to calculate the rolling force, and the lengths of flattening contact arcs of each element are calculated. Considering the flattening contact arc lengths and tensile stress synthetically, rolling force parameters are calculated iteratively. Then the corresponding procedure is developed, and the distribution of rolling force, pressure between rolls and tensile stress are calculated with this procedure. The results are basically consistent with the measured data, and it will be useful to thermal crown calculation and strip flatness control.

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.

A Reliability-Based Approach to Flatness Actuator Effectiveness in 20-High Rolling Mills

2012 ◽  
Author(s):  
Arif Malik ◽  
John Wendel ◽  
Mark Zipf ◽  
Andrew Nelson
Keyword(s):  
Rolling Force ◽  
Thin Sheet ◽  
Small Diameter ◽  
Global Market ◽  
Distribution Data ◽  
Control Mechanisms ◽  
Rolling Mills ◽  
Strip Flatness ◽  
Control Quality ◽  
Flatness Control

20-High rolling mills process high strength and/or very thin non-ferrous and ferrous metals using a complex, cluster arrangement of rolls. The 20-high roll cluster arrangement achieves specific flatness goals in the thin sheet by delivering maximum rolling pressure while minimizing the deflections of the small diameter rolls. 20-high mills also employ flatness control mechanisms with sophisticated actuators, such as those to shift intermediate rolls and deflect backup bearing shafts. The purpose of this is to compensate for variations in strip dimensional and mechanical properties which can cause poor flatness control quality from discrepancies in work-roll gap profile and distribution of rolling force. This suggests that the random property differences in the rolling parameters that substantially affect the flatness must be directly accounted for in flatness control algorithms in order to achieve strict flatness quality. The use of accurate mathematical models that account for the rolling pass target gage reduction can optimize the flatness control actuators and help gain an advantage in the thin gauge strip competitive global market. Based on the expected process parameter variations and nominal mill set-points (speed, tension, gage reduction, etc.), the mill’s process control computer should determine the probability that target flatness control quality will be met for a required length of strip. The process computer should then either modify the number of rolling passes or adjust the thickness reduction schedule before rolling begins to secure an improved flatness probability estimate if the probability of achieving target strip flatness is too low for the required deliverable quality. Therefore, this research integrates 1) 20-high roll-stack mill mathematical modeling, 2) probability distribution data for random important rolling parameters, 3) reliability-based models to predict the probability of achieving desired strip flatness, and 4) optimization examples. The results can be used to reduce wasted rolled metal from poor flatness before rolling.

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.

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.

Technical Characteristics and Application for a New Type of 8-Roll Cold Rolling Mill

2012 ◽  
Vol 572 ◽  
pp. 55-60 ◽  
Author(s):  
Peng Liu ◽  
Hong Bo Li ◽  
Zhi Qian Shen
Keyword(s):  
Cold Rolling ◽  
Rolling Mill ◽  
Work Roll ◽  
Fast Response ◽  
Cold Rolling Mill ◽  
Strip Flatness ◽  
Roll Bending ◽  
Roll Mill ◽  
Flatness Control ◽  
New Type

This paper focuses on a new type of 8-roll cold rolling mill with the back-up bearing roll. Compared to the traditional 6-roll cold rolling mill, a thick-walled bearing roll is used to multi-support the intermediate roll. By the rack, the fan-shaped gears, the eccentric core shaft and the servo-cylinder, the work roll can be pushed down by this screw down device on the top of the mill; By contrast with the 4(6)-roll mill, this type of mill has some characteristics, such as: the small size of rolls, lighter weight, the fast response for the screw down. The bearing roll is fixed by the supporting blocks placed on the rolling-mill housing. So this mill has large traverse rigidity, and this is propitious to the flatness control. By different means of strip flatness adjustments, such as the intermediate roll shifting, the roll bending and the bearing roll adjusting, the strip flatness can be well controlled. The oil-gas lubrication is used in the bearings of the bearing rolls, and the changing rolls equipment is designed for this type of mill too. A series of this type of mills (as 450, 800, 1250, 1450 series) have been produced since it was developed in 1997. The mills for 1250 and 1450 series have been applied in five-stand cold rolling mill and single stand reversing mill, a rolling speed of 800m/min has been achieved.

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