A Study on the Relationship Between the Variation of Rolling Parameters and the Vibration Characteristics of Twenty-High Rolling Mill

2016 ◽  
Author(s):  
Shao Yimin ◽  
Rao Meng ◽  
Yang Qihui ◽  
Yilin Yuan
Keyword(s):  
Dynamic Model ◽  
Rolling Mill ◽  
Rolling Force ◽  
Steel Strip ◽  
Vibration Characteristics ◽  
Strip Surface ◽  
Rolling Parameter ◽  
Adjustment Strategy ◽  
Chatter Marks

As a common defect in the production of high-quality steel strip, chatter marks are easily found on the strip surface which may resulting from inappropriate variation of rolling parameters of a twenty-high rolling mill and the quality of the strip surface can be significantly affected. Therefore, it is critical to understand the underlying relationship between the vibration mechanisms of chatter marks and rolling parameters, furthermore, an appropriate adjustment strategy of rolling parameters is needed to improve the quality of the strip surface. To addressing this problem, a dynamic model of the twenty-high rolling mill, coupling the vertical and horizontal vibrations (because of the variation in friction tension forces), is proposed to investigate the vibration characteristics under different rolling conditions. Based on this dynamic model, effects of rolling force, rolling speed and fluctuations of tension on the vibration of the twenty-high rolling mill are studied. Finally, a rolling parameter adjustment strategy is discussed and presented based on the research results.

More from the Mill

2000 ◽  
Vol 122 (10) ◽  
pp. 82-87
Author(s):  
Michael Valenti
Keyword(s):  
Cold Rolling ◽  
Control Systems ◽  
Rolling Mill ◽  
Space Shuttle ◽  
State Of The Art ◽  
Steel Strip ◽  
Cold Rolling Mill ◽  
Automated Control ◽  
The World

This article focuses on the launch of Sputnik that transfixed the world by Carpenter Technology Corp. By incorporating advanced processing equipment, including a rolling mill, shape controller, annealing furnaces, wet grinders, and leveler with state-of-the-art automated control systems, Carpenter has improved the productivity and quality of its high value strip at a time when Space Shuttle launchings are taken in stride. The Carpenter specialty strip facility installed a cold rolling mill designed by Joseph Frohling GmbH of Olpe, Germany, in November last year, to increase rolling capacity and guarantee that the steel strip it produces meets the desired shape and thickness. In the Frohling mill, strip passes between two working rolls that reduce its thickness to sizes between 0.150 and 0.008 inch, at speeds up to 1500 feet per minute. Carpenter also installed three Ebner vertical annealing furnaces. Coiled strip on mandrels is unwound through each furnace, annealed, then rewound continuously to promote productivity.

Stability analysis of the rolling process and regenerative chatter on 2030 tandem mills

2002 ◽  
Vol 216 (12) ◽  
pp. 1225-1235 ◽  
Author(s):  
Y Chen ◽  
S Liu ◽  
T Shi ◽  
S Yang ◽  
G Liao
Keyword(s):  
Stability Analysis ◽  
Rolling Mill ◽  
Rolling Process ◽  
Delay Effect ◽  
Regenerative Chatter ◽  
Vibration Model ◽  
Negative Damping ◽  
Time Delay Effect ◽  
Chatter Marks

Chatter in the rolling stack of high-velocity tandem mills and temper mills is a widespread problem and affects the quality of the finished product and the productivity of the rolling mill. One factor that clearly plays an important role in causing mill vibration is the inherent gap between the roll chocks and mill housings. In order to control chatter in cold rolling operations, a much deeper understanding of the basic mechanics of the problem is required. Therefore, this paper proposes a rolled piece vibration model for comprehending instability of the strip due to the variation of the friction coefficient in the roll bite. Subsequently, owing to the time delay effect of the chatter marks between the immediate stands, a regenerative chatter model is developed and stability analysis of the regenerative chatter model due to negative damping is presented. Finally, for a more detailed understanding of the regenerative chatter phenomena, a simulator is developed and industrial investigations are carried out in practice. It follows from the numerical simulations and industrial investigations that regenerative chatter is a more serious vibration phenomenon than simple chatter.

scholarly journals Multiple-Modal-Coupling Modeling and Stability Analysis of Cold Rolling Mill Vibration

2016 ◽  
Vol 2016 ◽  
pp. 1-26 ◽  
Author(s):  
Lingqiang Zeng ◽  
Yong Zang ◽  
Zhiying Gao
Keyword(s):  
Dynamic Model ◽  
Rolling Mill ◽  
Process Model ◽  
Rolling Force ◽  
Rolling Process ◽  
Dynamic Responses ◽  
System Stability ◽  
Force Model ◽  
Structure Model ◽  
Rolling Mill Vibration

An effective dynamic model is the basis for studying rolling mill vibration. Through analyzing characteristics of different types of vibration, a coupling vibration structure model is established, in which vertical vibration, horizontal vibration, and torsional vibration can be well indicated. In addition, based on the Bland-Ford-Hill rolling force model, a dynamic rolling process model is formulated. On this basis, the rolling mill vertical-torsional-horizontal coupled dynamic model is constructed by coupling the rolling process model and the mill structure model. According to this mathematical model, the critical rolling speed is determined and the accuracy of calculated results is verified by experimental data. Then, the interactions between different subsystems are demonstrated by dynamic responses in both time and frequency domains. Finally, the influences of process parameters and structure parameters on system stability are analyzed. And a series of experiments are conducted to verify the correctness of these analysis conclusions. The results show that the vertical-torsional-horizontal coupled model can reasonably characterize the coupling relationship between the mill structure and the rolling process. These studies are helpful for formulating a reasonable technological procedure of the rolling process and determining a feasible dynamic modification strategy of the structure as well.

Effects of Lubrication in Ferrite Rolling of Interstitial Free Steel

2013 ◽  
Vol 773-774 ◽  
pp. 186-191 ◽  
Author(s):  
Ning Kong ◽  
Kiet Tieu ◽  
Hong Tao Zhu ◽  
Qiang Zhu ◽  
Peter Gandy
Keyword(s):  
Solid Lubricant ◽  
Rolling Force ◽  
Steel Strip ◽  
Lubricating Oil ◽  
Interstitial Free ◽  
Strip Surface ◽  
Interstitial Free Steel ◽  
Ferrite Rolling ◽  
Roll Roughness ◽  
Lubrication Conditions

Ferrite rolling of interstitial free steel strip in the temperature range 650-850°C can effectively reduce furnace costs and scale formation as a result of lower strip reheating temperatures. Different lubrication conditions of lubricating oil, solid lubricant and dry condition were used during ferrite rolling tests of thin interstitial free steel strip on a 2-high Hille 100 experimental rolling mill. Different rolling speed, rolling temperature and reductions were applied to the rolling process. The rolling force and roll roughness were affected by the lubrication conditions and rolling parameters. Solid lubricant indicated an improved performance in terms of the roll roughness, as well as the oxidation property of the strip surface during ferrite rolling.

Mechanism of the Strip Surface Chatter Marks with 1220 Cold Rolling Mill

2014 ◽  
Vol 575 ◽  
pp. 376-381
Author(s):  
Chang Gui Xie ◽  
Hai Zeng
Keyword(s):  
Cold Rolling ◽  
Rolling Mill ◽  
Vibration Test ◽  
Vibration Source ◽  
Cold Rolling Mill ◽  
Strip Surface ◽  
Depth Study ◽  
The Relationship ◽  
Chatter Marks ◽  
Vibration Mill

Aiming at a 1220 strip surface, where the Cold Rolling Mill had chatter marks, on which the reasons for the formation was tracked tested for in-depth study. Based on the vibration test, the analysis was given to the dynamic characteristics of the rack [1-3]. It was found that had reaction to the mill that caused the forced vibration mill to further accelerate the formation of chatter marks. In the analysis of the mechanism on the chatter marks, the relationship between chatter marks spacing and vibration source was considered in successfully finding out the cause of the 1220 mill chatter marks generated, and then the chatter marks suppression measures were proposed with satisfied effects.

Dynamic Model of Rolling Mill’s Electro-Hydraulic Gap Adjustment System

2010 ◽  
Vol 659 ◽  
pp. 411-416 ◽  
Author(s):  
Attila Kővári
Keyword(s):  
Plastic Deformation ◽  
Dynamic Behavior ◽  
Rolling Force ◽  
Steel Strip ◽  
Dynamic Change ◽  
Rolled Strip ◽  
Technological Parameters ◽  
Material Quality ◽  
Roll Gap

Choosing of adequate shape technological parameters together with good chemical compound is very important to produce steel strip with required cross-section and material quality. The shaping rate, speed and time have an effect on strip mechanical and geometrical quality. The rate of shaping force needed for steel strip plastic deformation is determined by the strength of the steel forming. In rolling mills technology the plastic deformation of the strip is realized at high plastic strain speed so the dynamic change of shaping force might seriously affects the remaining stress of the rolled strip. The dynamic control of roll gap and force is realized with help of electrohydraulic servo actuator – so-called hydraulic capsules – which can adjust the roll gap at great rolling force dynamically. The quality of stand-mounted hydraulic capsule can greatly affect the dynamics of rolling, consequently the material quality of the rolling. The main contribution of the paper is to analyze the rolling dynamic behavior using the hydraulic capsule and rolling mill mathematical model together to show the changing of dynamic behavior of the system when internal sealing in hydraulic capsule is inefficient.

Lubricating Performances of Nano Organic-Molybdenum as Additives in Water-Based Liquid during Cold Rolling

2011 ◽  
Vol 337 ◽  
pp. 550-555 ◽  
Author(s):  
Bing Wang ◽  
Jian Lin Sun ◽  
Yuan Yuan Wu
Keyword(s):  
Cold Rolling ◽  
Rolling Force ◽  
Steel Strip ◽  
Optical Microscope ◽  
Wear Scar Diameter ◽  
Strip Surface ◽  
Steel Strips ◽  
Water Based ◽  
Save Energy ◽  
Steel Balls

The non-parathion nano organic molybdenum (Nano-Mo) was adopted to substitute for the conventional extreme-pressure and anti-wear additives, uniformly dispersed in water-based cold rolling liquid for steel strips. The tribological properties of the water-based cold rolling liquid were tested by the four-ball machine, and the lubricity of the cold-rolling liquid for steel strip was evaluated on the 4-high cold rolling experiments. Besides, the worn surfaces of the steel balls were observed by an optical microscope. Results indicated that Nano-Mo as additive in water-based cold rolling liquid, compared with the conventional emulsions, PB values was increased by 4%, and friction coefficient and wear scar diameter were decreased by 10.8% and 13.1%, the lubricity of rolling liquid was verified by cold rolling test which showed that this liquid had the excellent lubricant performance to reduce the rolling force, save energy consumption and get thinner strip. Optical microscope was used to observe the strips surface which showed that strip surface streaks were clear, scratches were less and shallow. By roughness test and EDS analysis, defects were filled with nanoparticles, friction and wear were reduced effectively. In addition, tensile properties had been studied after rolling lubrication, but the results showed no significant effect.

A Pilot Rolling Mill Designed for High Strength Steels

2010 ◽  
Vol 654-656 ◽  
pp. 210-213
Author(s):  
Zhi Jie Jiao ◽  
Jian Ping Li ◽  
Jie Sun
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Trip Steel ◽  
Rolling Mill ◽  
Rolling Force ◽  
Steel Strip ◽  
High Strength Steels ◽  
High Strength ◽  
Hydraulic Cylinders ◽  
Tension Control System

High strength steels, such as austenitic stainless steel, Transformation Induced Plasticity (TRIP) steel and silicon steel, have significant work hardening during cold rolling, which in turn induces a quickly increased rolling force. Tension plays a very important role in the reduction of the rolling force. However, coiler tension control system used in the classic experimental rolling mill requires long-scale strip, which cannot be satisfied for most experimental cases. To overcome this drawback, a new pilot rolling mill has been developed. The horizontally located hydraulic cylinders and clamps have been used to apply tension to the rolled short-scale strip. With this rolling mill, the austenitic stainless steel strip, TRIP steel strip and other high strength strips have been studied.

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