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.

Finite Element Analysis of Transient Thermal Problems of Work Rolls in Hot Rolling Process

1999 ◽  
Author(s):  
James D. Lee ◽  
Majid T. Manzari ◽  
Yin-Lin Shen ◽  
Wenjun Zeng
Keyword(s):  
Finite Element ◽  
Hot Rolling ◽  
Three Dimensional ◽  
Thermal Characteristics ◽  
Rolling Process ◽  
Thermal Problem ◽  
Element Analysis ◽  
Hot Rolling Process ◽  
Transient Thermal ◽  
Work Rolls

Abstract The three-dimensional transient thermal problem of work rolls in the entire hot rolling process has been formulated. It includes the time-varying boundary conditions specified at the roll surface taking the schedule of both rolling and idling cycles into consideration. The corresponding finite element equations are derived and solved by the Runge-Kutta-Verner method. The finite element solutions indicate that the temperature variations in the circumferential direction are overwhelming. Case studies unveil the thermal characteristics of the work rolls in various kinds of mill operations. Numerical results are presented and compared with Guo’s analytical solutions.

Numerical Simulation on Rolling Process of Medium Plate

2012 ◽  
Vol 602-604 ◽  
pp. 1864-1868 ◽  
Author(s):  
Lan Wei Hu ◽  
Xia Jin ◽  
Lei Shi ◽  
Sheng Zhi Li
Keyword(s):  
Contact Stress ◽  
Hot Rolling ◽  
Strain Field ◽  
Rolling Force ◽  
Metal Flow ◽  
Rolling Process ◽  
Slab Thickness ◽  
Actual Process ◽  
Hot Rolling Process ◽  
Rolling Efficiency

A 3-D thermal-mechanical model was built to simulate the hot rolling process of medium plate, with the aid of nonlinear commercial FE code MSC.SuperForm on a company's actual process parameters. The hot rolling process of single-pass which slab thickness is 180mm was simulated, and the influence of pass reduction on metal flow, stress-strain field, contact stress and rolling force were researched. The study revealed that pass reduction should be at least 20% by increase depress in pass in addition to rolling efficiency. As that, rolling efficiency be increased, roll contact stress be brought down, and its service life be prolonged. And metal plastic strain enhanced, metal flow increased, but its strain field non-uniformly distributed, metal flow and plastic deformation would be strengthen by increase pass reduction, and the lateral broadening in the head is bigger than that in the tail.

scholarly journals Research on rolling force model in hot-rolling process of aluminum alloys

2011 ◽  
Vol 16 ◽  
pp. 745-754 ◽  
Author(s):  
Huang Changqing ◽  
Deng Hua ◽  
Chen Jie ◽  
H.U Xinghua ◽  
Yang Shuangcheng
Keyword(s):  
Aluminum Alloys ◽  
Hot Rolling ◽  
Rolling Force ◽  
Rolling Process ◽  
Force Model ◽  
Hot Rolling Process

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 On the Evolution of Temperature and Combined Stress in a Work Roll under Cyclic Thermo-Mechanical Loadings during Hot Strip Rolling and Idling

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5054
Author(s):  
Kejun Hu ◽  
Qinghe Shi ◽  
Wenqin Han ◽  
Fuxian Zhu ◽  
Jufang Chen
Keyword(s):  
Thermal Stress ◽  
Hot Rolling ◽  
Work Roll ◽  
Rolling Process ◽  
Roll Surface ◽  
Hot Strip Rolling ◽  
Strip Rolling ◽  
Hot Strip ◽  
Calculation Results ◽  
Work Rolls

An accurate prediction of temperature and stress evolution in work rolls is crucial to assess the service life of the work roll. In this paper, a finite element method (FEM) model with a deformable work roll and a meshed, rigid body considering complex thermal boundary conditions over the roll surface is proposed to assess the temperature and the thermal stress in work rolls during hot rolling and subsequent idling. After that, work rolls affected by the combined action of temperature gradient and rolling pressure are investigated by taking account of the hot strip. The accuracy of the proposed model is verified through comparison with the calculation results obtained from the mathematical model. The results show that thermal stress is dominant in the bite region of work rolls during hot rolling. Afterwards, the heat treatment residual stresses which are related to thermal fatigue are simulated and introduced into the work roll as the initial stress to evaluate the redistribution under the thermal cyclic loads during the hot rolling process. Results show that the residual stress significantly changed near the roll surface.

scholarly journals Load Distribution of Evolutionary Algorithm for Complex-Process Optimization Based on Differential Evolutionary Strategy in Hot Rolling Process

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Xu Yang ◽  
Chang-bin Hu ◽  
Kai-xiang Peng ◽  
Chao-nan Tong
Keyword(s):  
Evolutionary Algorithm ◽  
Process Optimization ◽  
Hot Rolling ◽  
Optimization Model ◽  
Load Distribution ◽  
Rolling Force ◽  
Rolling Process ◽  
Evolutionary Strategy ◽  
Hot Rolling Process ◽  
Complex Process

Based on the hot rolling process, a load distribution optimization model is established, which includes rolling force model, thickness distribution model, and temperature model. The rolling force ratio distribution and good strip shape are integrated as two indicators of objective function in the optimization model. Then, the evolutionary algorithm for complex-process optimization (EACOP) is introduced in the following optimization algorithm. Due to its flexible framework structure on search mechanism, the EACOP is improved within differential evolutionary strategy, for better coverage speed and search efficiency. At last, the experimental and simulation result shows that evolutionary algorithm for complex-process optimization based on differential evolutionary strategy (DEACOP) is the organism including local search and global search. The comparison with experience distribution and EACOP shows that DEACOP is able to use fewer adjustable parameters and more efficient population differential strategy during solution searching; meanwhile it still can get feasible mathematical solution for actual load distribution problems in hot rolling process.

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.

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