scholarly journals Asymmetric rolling process

2017 ◽  
Vol 64 (3) ◽  
pp. 151-160 ◽  
Author(s):  
Peter Fajfar ◽  
Alenka Šalej Lah ◽  
Jakob Kraner ◽  
Goran Kugler
Keyword(s):  
Rolling Force ◽  
Work Roll ◽  
Rolling Process ◽  
Metallic Materials ◽  
Asymmetric Rolling ◽  
Asymmetrical Rolling ◽  
Novel Technique ◽  
High Degree ◽  
Large Shear Strain ◽  
Roll Drive

Abstract Asymmetric rolling is a novel technique used to control both the texture and the grain refinement of metallic materials. The aim of asymmetric rolling is to apply a large shear strain uniformly through the thickness of the plate, by maintaining a high degree of friction between the sheet and the rolls. It can be used to improve the formability of material. One of the advantages of asymmetrical rolling is that the rolling force and torque can be decreased. The methods used for the asymmetric rolling are single roll drive, different work roll speeds, different work roll diameters or different lubricated work roll surfaces.

Finite Element Analysis of Thin Strip Profile in Asymmetric Cold Rolling Considering Work Roll Crossing and Shifting

2014 ◽  
Vol 1061-1062 ◽  
pp. 515-521 ◽  
Author(s):  
Abdulrahman Aljabri ◽  
Zheng Yi Jiang ◽  
Dong Bin Wei
Keyword(s):  
Finite Element ◽  
Cold Rolling ◽  
Finite Element Model ◽  
Rolling Force ◽  
Element Model ◽  
Work Roll ◽  
Rolling Process ◽  
Thin Strip ◽  
Asymmetric Rolling ◽  
Element Analysis

Cold rolled thin strip has received a great deal of attention through technological and theoretical progress in the rolling process, as well as from researchers who have focused on some essential parameters of strip such as its shape and profile. This paper describes the development of a 3-D finite element model of the shape of thin strip during cold rolling to simulate the cold rolling of WCS (work roll crossing and shifting) in asymmetric rolling. This finite element model considers the asymmetrical rolling parameters such as variations in the diameters of the rolls and the crossing angle as the work roll shifts on the strip during cold rolling. The shape and profile of the strip are discussed in the asymmetrical and symmetrical rolling conditions, while the total rolling force and distribution of stress are discussed in the case where the roll cross angle and axial shifting roll changes. The results can then be used to control the shape and profile of thin strip during rolling.

Mechanics of Asymmetric Rolling of Thin Strip with Effect of Work Roll Edge Contact

2007 ◽  
Vol 561-565 ◽  
pp. 115-118
Author(s):  
Zheng Yi Jiang ◽  
Hai Bo Xie ◽  
L.M. Yang ◽  
Hong Tao Zhu ◽  
Dong Bin Wei ◽  
...  
Keyword(s):  
Rolling Force ◽  
Work Roll ◽  
Contact Length ◽  
Thin Strip ◽  
Asymmetric Rolling ◽  
Edge Contact ◽  
Roll Bending ◽  
Work Rolls ◽  
Strip Crown ◽  
Small Work

Asymmetric rolling of thin strip has become important due to a significant decrease of rolling force, which contributes to obtain the extremely thin strip, to reduce the rolling passes, and to save the energy by a decrease of anneal treatment. In asymmetric rolling of thin strip, edges of work rolls may contact and deform when no or small work roll bending force is applied. Work roll edge contact forms a new deformation feature. In this paper, the effects of initial thickness of strip and friction coefficient on the rolling pressure, roll edge contact length and strip crown during asymmetric rolling of thin strip with work roll edge contact effect has been discussed, and the calculated rolling force with work roll edge contact is compared with the measured value.

scholarly journals Coupled Vibration Characteristics Analysis of Hot Rolling Mill with Structural Gap

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Guangxu Zhang ◽  
Jiahan Bao ◽  
Wenhao Li ◽  
Zhichong Wang ◽  
Xiangshuai Meng
Keyword(s):  
Hot Rolling ◽  
Rolling Mill ◽  
Process Model ◽  
Elastic Recovery ◽  
Rolling Force ◽  
Excitation Amplitude ◽  
Work Roll ◽  
Rolling Process ◽  
Structure Model ◽  
Rolling Mills

It is important to study the vibration of rolling mills to improve the stability of rolling production. A dynamic rolling process model is established by considering the elastic recovery of the exit strip and the influence of multiroll equilibrium, and the accuracy of the model is verified by experimental data. On this basis, based on the distribution of friction force in the deformation zone, the rolling force and rolling torque are nonlinearized. In addition, a rolling mill structure model is established by considering the structure gap and a piecewise nonlinear horizontal-vertical-torsional vibration model of the rolling mill is established by combining the structure model and dynamic rolling process model. Finally, the amplitude-frequency characteristics of the work roll under different external excitation amplitude and the dynamic bifurcation characteristics of the work roll under different gaps are analyzed. The study indicates that, by reducing excitation amplitude and structure gap, the system vibration can be reduced. The research results can provide a theoretical reference for further exploration of the coupling vibration of hot rolling mills.

scholarly journals Investigation of the influence of hot asymmetric long products on the formation of the microstructure, mechanical properties and service characteristics of finished products

2019 ◽  
pp. 156-172
Author(s):  
V.G. Razdobreev ◽  
D.G. Palamar
Keyword(s):  
Mechanical Properties ◽  
Carbon Steel ◽  
Dislocation Density ◽  
Rolling Force ◽  
Diffraction Method ◽  
Rolling Process ◽  
Crystalline Lattice ◽  
Asymmetric Rolling ◽  
Rolling Shear ◽  
Rolling Technology

The aim of the work is to study the influence of the process of hot asymmetric rolling on the structural state, mechanical properties and operational characteristics of long products of simple form from ordinary carbon steel. To simulate the process of asymmetric high-quality rolling, the mathematical model previously developed in the ISI added the possibility of taking into account cases of rolling in a pair of rolls of different diameters, rolling in a pair of rolls of different materials, rolling with one drive and one non-drive rolls, rolling at different speeds in a pair of rolls and other. The calculations showed a reduction in rolling force to 10 % with an asymmetric rolling process compared to the traditional rolling process. The study of the features of the process of hot asymmetric rolling (shear rolling) compared with the traditional rolling process was carried out under industrial conditions in the production of a 12x12 mm square profile from ordinary low-carbon steel St3sp. It was found that the average values of HRB, σВ, and σТ in the studied samples practically do not differ, and the average values of δ5 are higher by 8 % (abs.) or ~ 27 % (rel.) In samples that were rolled using the asymmetric rolling technology than in samples that were rolled using traditional rolling technology. The estimation of dislocation density by the X-ray diffraction method showed that during hot asymmetric rolling, the dislocation density is reduced by ~ 46% due to the active flow of in-situ polygonization and recrystallization processes during deformation. In this case, the average values of the microfractures of the crystalline lattice of ferrite are 21% lower in the samples obtained by the method of asymmetric rolling than in the samples obtained by traditional rolling. For the first time, a decrease in the total atmospheric corrosion rate was found in samples that were rolled using asymmetric rolling technology (0.39 g/m2xh) compared to samples that were rolled using traditional rolling technology (0.445 g/m2xh).

An Investigation of the Effect of Speeds of Work Rolls on Rolling Strip

1995 ◽  
Vol 117 (3) ◽  
pp. 341-346 ◽  
Author(s):  
Zone-Ching Lin ◽  
Y. C. Cheng
Keyword(s):  
Hot Rolling ◽  
Rolling Force ◽  
Large Strain ◽  
Work Roll ◽  
Rolling Process ◽  
Analysis Model ◽  
Hot Rolling Process ◽  
Rolling Strip ◽  
Work Rolls ◽  
Thermoelastic Plastic

The paper is an investigation of strip curvature caused by the different speeds between the upper work roll and the lower work roll in the rolling process for an aluminum strip. At the same time, we analyzed the variations in the temperature field and strain field, and used a method of speeds variation of the upper and lower work rolls to calibrate the deformation curvature caused by the coolant condition in the hot rolling process. Based on the large deformation-large strain theory, and by means of the Updated Lagrangean Formulation (ULF) and increment theory, a coupled thermoelastic-plastic analysis model for hot rolling process is thus constructed. At the same time the finite difference method was also used to solve the transient heat transfer equation. Finally, the numerical analysis method developed in this study was employed to analyze the changes in the aluminum strip’s temperature and other changes during rolling. In addition, the average rolling force obtained from the simulation was compared with that from the experiments. It verified that the model in this study is reasonable.

scholarly journals Thin Strip Profile Control Capability of Roll Crossing and Shifting in Cold Rolling Mill

2013 ◽  
Vol 773-774 ◽  
pp. 70-78 ◽  
Author(s):  
Abdulrahman Aljabri ◽  
Zheng Yi Jiang ◽  
Dong Bin Wei ◽  
Xiao Dong Wang ◽  
Hasan Tibar
Keyword(s):  
Cold Rolling ◽  
Rolling Mill ◽  
Rolling Force ◽  
Work Roll ◽  
Rolling Process ◽  
Thin Strip ◽  
Strip Rolling ◽  
Strip Shape ◽  
Strip Profile ◽  
Profile Control

Controlling cold strip profile is a difficult and significant problem has been found in industry during thin strip rolling. At present choosing the new type of strip rolling mill is the one of main methods to control the strip shape quality in cold rolling. The influences of rolling process parameters such as the work roll cross angle and work roll shifting on the strip shape and profile of thin strip are recognised throughout this study. The results show that the roll crossing and shifting is efficient way to control the strip shape. The increase of the work roll crossing angle would lead to improve the strip profile significantly by decreasing the exit strip crown and edge drop. The strip profile would be enhanced if the axial roll shifting was increased. Moreover, the total rolling force was analysed in detail by changing the roll cross angle and axial shifting roll.

scholarly journals Analysis of Thin Strip Profile during Asymmetrical Cold Rolling with Roll Crossing and Shifting Mill

2014 ◽  
Vol 894 ◽  
pp. 212-216 ◽  
Author(s):  
Abdulrahman Aljabri ◽  
Zheng Yi Jiang ◽  
Dong Bin Wei
Keyword(s):  
Cold Rolling ◽  
Shape Control ◽  
Work Roll ◽  
Rolling Process ◽  
Thin Strip ◽  
Asymmetrical Rolling ◽  
Strip Shape ◽  
Strip Profile ◽  
Profile Control ◽  
The One

Strip profile control during rolling is required to assure the dimensional quality of rolled thin strip is acceptable for customers. Throughout rolling, the strip profile is controlled by using the advanced shape control rolling mill, such as the combination of work roll crossing and shifting during asymmetrical rolling, the one of the valuable methods to control the strip profile quality in rolling process. In this paper, the influences of cold rolling parameters such as the crossing angle and axial shifting value of work rolls on the strip profile are analysed. The strip shape control is discussed under both symmetrical and asymmetrical rolling conditions. The obtained results are appropriate to control the rolled thin strip profile in practice.

Study on Tribological Property of Nano-TiO2 Additive Oil-in-Water Lubricant during Hot Rolling

2016 ◽  
Vol 874 ◽  
pp. 381-386 ◽  
Author(s):  
Wen Zhen Xia ◽  
Jing Wei Zhao ◽  
Hui Wu ◽  
Si Hai Jiao ◽  
Zheng Yi Jiang
Keyword(s):  
Power Consumption ◽  
Oxide Scale ◽  
Hot Rolling ◽  
Tribological Property ◽  
Rolling Force ◽  
Work Roll ◽  
Rolling Process ◽  
Tribological Behaviour ◽  
Oil In Water ◽  
The Coefficient Of Friction

Oxide scale formed on the steel surface during hot rolling affects the tribological property of nanoTiO2 additive oil-in-water (O/W) lubricant, resulting in changes of roll forces, torques and power consumption, as well as the wear and the surface quality of the work roll and workpiece in hot rolling. The nanoparticle additive O/W emulsion is a novel lubricant and has a great potential to be used in hot rolling process. However, little research has focused on the nanoparticle additive O/W emulsion. In this study, oxidation, tribological and hot rolling tests were conducted to investigate the tribological behaviour of nanoTiO2 additive O/W lubricant. The results indicate that the surface morphology of the oxide scale plays an important role in tribological behaviour of nanoTiO2 additive O/W lubricants. The coefficient of friction (COF) and rolling force are reduced with the addition of nanoTiO2 particles into the 1.0% (mass %, oil concentration) O/W lubricant. This study is helpful in applying the nanoTiO2 additive O/W lubricant during hot rolling to realise reduction of rolling force and power consumption.

Development and Application of Hot Rolling Lubrication Control System Based on Expert System

2012 ◽  
Vol 442 ◽  
pp. 366-369
Author(s):  
Liang Gui Peng ◽  
Xian Lei Hu ◽  
Xu Li ◽  
Dian Hua Zhang ◽  
Gui Ling Yang ◽  
...  
Keyword(s):  
Expert System ◽  
Hot Rolling ◽  
Rolling Force ◽  
Reference Value ◽  
Work Roll ◽  
Rolling Process ◽  
Thin Strip ◽  
Hot Strip Mill ◽  
Lubrication System ◽  
Online Application

To integrate a new roll gap lubrication system into an existing hot strip mill is a challenge problem. A lubrication expert system was developed and embedded into finish rolling setup system. The reference value setup by expert system is downloaded to roll bite lubrication PLC via finish mill PLC to open oil spraying valve and regulate the oil concentration. Oil spraying time sequence is an important factor to make good lubrication effect and to keep the rolling process stable. Since online application of the hot rolling lubrication system, rolling force and work roll wear has been reduced dramatically, especially rolling thin strip.

scholarly journals Asymmetric (Hot, Warm, Cold, Cryo) Rolling of Light Alloys: A Review

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 956
Author(s):  
Denis Pustovoytov ◽  
Alexander Pesin ◽  
Puneet Tandon
Keyword(s):  
Mechanical Properties ◽  
Deformation Zone ◽  
Large Scale ◽  
Rolling Force ◽  
Vertical Plane ◽  
Relevant Information ◽  
Rolling Process ◽  
Technological Parameters ◽  
Asymmetric Rolling ◽  
Sheet Rolling

Asymmetric sheet rolling is a process used when there are differences in any technological parameters in the horizontal plane across the width of the deformation zone or in the vertical plane between the top and bottom surfaces of the deformation zone. Asymmetry can either have random causes, or it can be created purposefully to reduce rolling force, improve sheet flatness, minimize the ski effect, obtain thinner sheets and for grain refinement and improvement of texture and mechanical properties of sheet metals and alloys. The purpose of this review is to analyze and summarize the most relevant information regarding the asymmetric (hot, warm, cold, cryo) rolling processes in terms of the effect of purposefully created asymmetry on grain size and mechanical properties of pure Mg, Al, Ti and their alloys. The classification and fundamentals of mechanics of the asymmetric rolling process are presented. Based on the analysis of publications related to asymmetric rolling, it was found that a superior balance of strength and ductility in pure Mg, Al, Ti and their alloys could be achieved due to this processing. It is shown that asymmetric rolling in comparison with conventional severe plastic deformation methods have an undeniable advantage in terms of the possibility of the production of large-scale sheets.

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