Inhomogeneity of temperature distribution through thickness of the aluminium strip during hot rolling (original) (raw)
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Thermal Camber and Temperature Evolution on Work Roll during Aluminum Hot Rolling
Metals
Flatness is an important quality characteristic for rolled products. Modern hot rolling mills are equipped with actuators that can modify the uneven thickness distribution across the width of the strip (crown), taking into account online measurements of various process parameters such as temperature, force and exit strip profile, either automatically or manually by the operator. However, the crown is also influenced by many parameters that cannot easily be measured during production, such as work roll temperature evolution through thickness and roll geometric variation due to thermal expansion (thermal camber). These have an impact on the strip flatness. In this paper, a thermo-mechanical finite element model on LS-DYNA™ software was utilized to predict the influence of process parameters, and more specifically strip temperature, cooling strategy (application of cooling on the entry or entry and exit side simultaneously) and roll core temperature, on the evolution of roll temperatur...
Journal of Iron and Steel Research, International, 2007
Based on the thermal conduction equations, the threedimensional (3D) temperature field of a work roll was investigated using finite element method (FEM). The variations in the surface temperature of the work roll during hot strip rolling were described, and the thermal stress field of the work roll was also analyzed. The results showed that the highest roll surface temperature is 593 ' C , and the difference between the minimum and maximum values of thermal stress of the work roll surface is 145. 7 MPa. Furthermore, the results of this analysis indicate that temperature and thermal stress are useful parameters for the investigation of roll thermal fatigue and also for improving the quality of strip during rolling.
Journal of Iron and Steel …, 2007
Based on the thermal conduction equations, the threedimensional (3D) temperature field of a work roll was investigated using finite element method (FEM). The variations in the surface temperature of the work roll during hot strip rolling were described, and the thermal stress field of the work roll was also analyzed. The results showed that the highest roll surface temperature is 593 ' C , and the difference between the minimum and maximum values of thermal stress of the work roll surface is 145. 7 MPa. Furthermore, the results of this analysis indicate that temperature and thermal stress are useful parameters for the investigation of roll thermal fatigue and also for improving the quality of strip during rolling.
Parametric Study of Hot Rolling Process by the Finite Element Method
2009
Abstract. In the present investigation, a hot rolling process of AA5083 aluminum alloy is simulated. The approach is based on the thermo-mechanical analysis of the problem using the Finite Element Method (FEM). The temperature distribution in the roll and the slab, the stress, strain and strain rate elds, are extracted throughout a transient analysis of the process.
Finite Element Simulation of Hot Rolling for an Aluminium 2024 Plate
Numerical simulation has become an important tool in the rolling industry. The use of two dimensional rolling model is quite common in Aluminum industries. In the present work A two dimensional elasto-plastic Finite Element model for hot rolling of an Aluminum plate has been developed. This model is used to study the behavior of the material under different values of coefficient of friction, roller diameter and initial thickness of the plate for attaining a specified final thickness of the rolled plate. The effect of coefficient of friction, initial thickness of plate and roller radius on maximum stress, equivalent plastic strain and reaction force has been studied. The current work has been carried out using the Finite Element software ABAQUS 6.10 (Explicit).
Thermomechanical Behavior of Work Rolls During Warm Strip Rolling
A mathematical model was developed to assess thermomechanical behavior of work rolls during warm rolling processes. A combined finite element analysis-slab method was first developed to determine thermal and mechanical responses of the strip being rolled under steady-state conditions, and then, the calculated roll pressure and temperature field were utilized as the governing boundary conditions for the thermomechanical problem of the work roll. Finally, the thermomechanical stresses within the work rolls were predicted by a thermoelastic finite element approach. The results of the model indicate that, in warm strip rolling, thermal and mechanical stresses developed in the work rolls are comparable, and thus, both thermal and mechanical aspects of the problem should be considered in such a problem. Besides, the model was shown to be capable of determining the effects of various rolling parameters
Experimental Measurement of the Deformation in Hot Rolling of Aluminium 1% Mn: The Grid Technique
Applied Mechanics and Materials, 2005
The grid technique is an experimental method for measuring the deformation in hot rolling. An AA3004 sample -fitted with an insert -was rolled in a single hot rolling pass at 400 o C. The insert was hand engraved with a 1x1 mm grid and the analysis of the image of the deformed grid enabled the calculation of the components of the deformation gradient tensor. In order to prevent relative motion between the insert and the work-piece, four steel pins were used; after the test no detachment was observed between insert and sample. The temperature was monitored during rolling using two embedded thermocouples, one close to the surface and the other on the centre-line of the slab. The commercial finite element (FE) code ABAQUS was used to build a three-dimensional model of the rolling process. The recorded temperature was compared with the FE values evaluated after tuning the heat transfer coefficient. The FE model was run several times with different friction coefficients and the deformation gradient checked against the experimental measurement of the deformed grid in order to obtain the optimum friction coefficient. The experimentally determined deformation gradient and the measured temperature agreed well with the numerical values. Figure 1 -'Earing' of a cup after deep-drawing from a rolled sheet of aluminium (source
Parametric Analysis of Hot Rolling Process
International Journal Of Mechanical Engineering And Information Technology, 2016
In today's scenario finite element simulation has become an important tool in the manufacturing industry. Rolling process plays an important role in manufacturing of different parts with a long range variety of dimensions. In the process of rolling, the internal raw material transform into desired shape by passing through one or more pairs of rolls. The main aim of this paper is to investigate the influence of Modelling and Simulation of different parameters such as geometry of the slab, friction between work-rolls and slab, rotational speed of work-roll, percentage of thickness reduction of slab while using rolling process. Two dimensional rolling models are used routinely in most aluminium manufacturing companies. In present research, a two dimensional elasto-plastic Finite Element model for hot rolling of a plate of aluminium has been developed to study the behavior of the paticular material under different coefficients of friction, different roller diameters and different initial thickness of the metal plate for obtaining a particular final thickness of the rolled plate. The individual effects of coefficient of friction, roller radius, and initial thickness of plate on maximum stress, strain, strain rate, equivalent plastic strain and reaction force have been obtained. The results of finite element simulation can be used to investigate the effects of parameters on mechanical properties and product integrity.
Numerical Simulation of Strip Shape of High-Strength Steel during Hot Rolling Process
Key Engineering Materials, 2020
High-strength steel is widely applied due to its excellent mechanical properties. However, its high strength in turn brings great difficulties to production and processing such as hot strip rolling owing to the high rolling force, which results in large elastic deformation of roll stack and poses a huge challenge to the control of strip crown and flatness. In this paper, A three-dimensional (3D) elastic-plastic coupled thermo-mechanical finite element (FE) model for hot strip rolling of high-strength steel is developed and then verified experimentally. This model not only calculates the elastic deformation of rolls and plastic deformation of strip simultaneously, but also considers the effect of temperature variation during hot strip rolling. Based on this valid model, the effects of bending force and shifting value of work roll (WR), back-up roll (BR) size, entrance strip crown and rolling force on strip crown have been investigated quantitatively. The results obtained provide valu...
Temperature distribution in the roll-gap during hot flat rolling
Journal of Materials Processing Technology, 1992
A knowledge of the temperature distribution in the roll-gap during hot rolling is essential for accurate prediction of the roll force and of the microstructure in the rolled strip. Theoretical models that are used to predict temperature distribution in the roll-gap require accurate values of the coefficient of heat transfer between the surfaces of the roll and strip (hRs). Measured values of hRS applicable to hot rolling of aluminium are reported. The effect of different pass reductions, roll pressure distribution and lubrication on the coefficient of heat transfer is examined. 0924-0136/92/$05.00