scholarly journals Modeling of Rolling Force for Thick Plate of Multicomponent Alloys and Its Application on Thickness Prediction

2021 ◽  
Vol 8 ◽  
Author(s):  
Shun Hu Zhang ◽  
Jia Lin Xin ◽  
Li Zhi Che
Keyword(s):  
Thick Plate ◽  
Rolling Force ◽  
Yield Criterion ◽  
Metal Flow ◽  
Rolling Process ◽  
Logistic Function ◽  
Force Model ◽  
Multicomponent Alloys ◽  
Thickness Prediction ◽  
Predicted Values

During the rolling process of thick plate, the nonlinear specific plastic power that derived from the non-linear Mises yield criterion is difficult to be integrated, which has restricted the establishment of a rolling force model. To solve this problem, a new yield criterion is firstly established, and then used to derive a linear specific plastic power. Meanwhile, a kinematically admissible velocity field whose horizontal velocity component obeys the Logistic function is proposed to describe the metal flow of the deformed plate. On these bases, the rolling energy items including the internal deformation power of the deformed body, friction power on the contact surface, and shear power on the entry and exit sections are integrated successively, and the rolling force model is established. It is proved that the model can predict the rolling force well when compared with the actual data of multicomponent alloys. Besides, the formula for predicting the outlet thickness is ultimately given upon this derived model, and a good agreement is also found between the predicted values and the actual ones, since the absolute errors between them are within 0.50 mm.

scholarly journals Analysis of Rolling Force for Extra-Thick Plate with CA Criterion

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Shun Hu Zhang ◽  
Lei Deng ◽  
Peng Li
Keyword(s):  
Temperature Rise ◽  
Power Dissipation ◽  
Thick Plate ◽  
Control Method ◽  
Rolling Force ◽  
Yield Criterion ◽  
Inner Product ◽  
Relative Reduction ◽  
Force Model ◽  
Theoretical Results

In order to solve the nonlinear integral difficulty of the Mises yield criterion, a linear yield criterion, called the collaborative approximation (CA) yield criterion, is proposed by the collaborative control method. According to the approximation method, the mathematical expression of the CA yield criterion is derived as a linear function of the three principal stresses. The theoretical results based on the yield criterion in the form of the Lode parameter are verified with the classical test data, and a good agreement is found. Meanwhile, for the purpose of proving the effectiveness of the yield criterion, its specific plastic power is derived and applied to establish the rolling force model of an extra-thick plate. In the modeling, the internal power of plastic deformation is obtained by using the derived specific plastic power, while the shear power dissipation and the frictional power dissipation are obtained by using the methods of strain vector inner product and average velocity integration. Then, the analytical solution of the rolling force is obtained and then extended to the one accounting for the temperature rise. The maximum errors of the predicted rolling torque and rolling force without considering the temperature rise are 12.72% and 11.78%, respectively, while those considering the temperature rise decrease to 3.54% and 5.23%, respectively. Moreover, the influence of relative reduction, friction factor, surface temperature, and the temperature rise of the workpiece on the theoretical results is discussed.

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

Research and Improvement on the Rolling Force Model of Plate

2010 ◽  
Vol 97-101 ◽  
pp. 3091-3096 ◽  
Author(s):  
Jun Wang ◽  
Chun Li Jia ◽  
Zhong Zhao ◽  
Zhi Jie Jiao ◽  
Jian Ping Wang
Keyword(s):  
Rolling Force ◽  
Rolling Process ◽  
The Self ◽  
Force Model ◽  
Physical Conditions ◽  
The Core ◽  
Predictive Error ◽  
On Line ◽  
Self Learning ◽  
Thickness Layer

Rolling force model is the core of all the mathematical models of plate for rolling process, but the accuracy of traditional rolling force model is not high enough in application, so in this study the rolling force model of plate is researched and improved. The effects of different physical conditions on resistance of deformation are decoupled, and the formula acquired is practical. While the composition, Nb is used to calculate residual strain. At the same time, the self-learning method, which is based on the thickness layer is applied. The on-line application results show that the predictive error between force model calculated and measured can be controlled at less than 9% and 80% of the passes can be controlled within 5%.

SIMULATION OF MULTI-PASS HOT ROLLING BY A MIXED ANALYTICAL-NUMERICAL METHOD

2011 ◽  
Vol 03 (03) ◽  
pp. 469-489 ◽  
Author(s):  
JINLING ZHANG ◽  
ZHENSHAN CUI
Keyword(s):  
Mathematical Model ◽  
Flow Stress ◽  
Strain Rate ◽  
Numerical Method ◽  
Hot Rolling ◽  
High Efficiency ◽  
Rolling Force ◽  
Metal Flow ◽  
Fem Simulation ◽  
Rolling Process

A mathematical model integrating analytical method with numerical method was established to simulate the multi-pass plate hot rolling process, predicting its strain, strain rate, stress and temperature. Firstly, a temperature analytical model was derived through series function solution, the coefficients in which for successive processes were smoothly transformed from the former process to the latter. Therefore, the continuous computation of temperature for multi-operation and multi-pass was accomplished. Secondly, kinematically-admissible velocity function was developed in Eulerian coordinate system according to the principle of volume constancy and characteristics of metal flow during rolling with undetermined coefficients — which were eventually solved by Markov variational principle. Thirdly, strain rate was calculated through geometric equations and the difference-equations for solving strain and a subsequent recurrent solution were established. Fourthly, rolling force was calculated on the base of Orowan equilibrium equation, considering the contribution to flow stress of strain, strain rate and temperature, rather than taking the flow stress as a constant. Consequently, the thermo-mechanics and deformation variables are iteratively solved. This model was employed in the simulation of an industrial seven-pass plate hot rolling schedule. The comparisons of calculated results with the measured ones and the FEM simulation results indicate that this mathematical model is able to reasonably represent the evolutions of various variables during hot rolling so it can be used in the analysis of practical rolling. Above all, the greatest advantage of the presented is the high efficiency. It costs only 12 seconds to simulate a seven-pass schedule, more efficient than any other numerical methods.

scholarly journals Modeling of rolling force of ultra-heavy plate accounting for gradient temperature

2021 ◽  
Vol 13 (9) ◽  
pp. 168781402110476
Author(s):  
Shun Hu Zhang ◽  
Li Zhi Che
Keyword(s):  
Temperature Distribution ◽  
Velocity Field ◽  
Decomposition Method ◽  
Rolling Force ◽  
Metal Flow ◽  
Maximum Error ◽  
Root Vector ◽  
Force Model ◽  
Heavy Plate ◽  
Vector Decomposition

In this paper, the nonlinear specific plastic power of the Mises criterion is integrated analytically to establish the rolling force model of gradient temperature rolling for an ultra-heavy plate by a new method called the root vector decomposition method. Firstly, the sinusoidal velocity field is proposed in terms of the characteristics of metal flow during ultra-heavy plate rolling, which satisfies the kinematically admissible condition. Meanwhile, the characteristics of the temperature distribution along the thickness direction of the plate during the gradient temperature rolling is described mathematically. Based on the velocity field and the temperature distribution expression, the rolling energy functional is obtained by using the root vector decomposition method, and the analytical solution of rolling force is derived according to the variational principle. Through comparison and verification, the rolling force model solved by the root vector decomposition method in this paper is in good agreement with the measured one, and the maximum error of the rolling force is just 10.21%.

Influence of Wall Thickness Fluctuation of Pierced Shell on Continuous Tube Rolling Process of Semi-Floating Mandrel Mill

2011 ◽  
Vol 189-193 ◽  
pp. 2382-2386
Author(s):  
Yuan De Yin ◽  
Sheng Zhi Li ◽  
Yong Lin Kang ◽  
Yang Hua Li ◽  
Gong Ming Long ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Rolling Force ◽  
Metal Flow ◽  
Equivalent Plastic Strain ◽  
Rolling Process ◽  
Steel Tube ◽  
Transverse Wall ◽  
Tube Rolling ◽  
Boiler Steel ◽  
Rolling Moment

In continuous tube rolling process, wall thickness reduction per stand will be changed due to wall thickness fluctuation of pierced shell caused by piercing process, which results in changes in metal flow conditions and affects force parameters, deformation parameters, especially transverse wall thickness precision of rolled hollow tube. In this paper, with the aid of commercial FE code MSC.SuperForm, the high pressure boiler steel tube continuous rolling process of a typical hollow tube specification 133.0×4.0mm are simulated based on 133 main pass sequence of 89mm 6-stand semi-floating mandrel mill, and force parameters, equivalent plastic strain, transverse wall thickness precision, outline dimension and real roundness of rolled hollow tube are analyzed and compared on the condition of two different wall thicknesses of pierced shell. Analysis results indicate that force parameters increase with wall thickness of pierced shell, maximal rolling force, rolling moment and mandrel axial force increase 10% or so in the first three stands when rolling pierced shell of wall thickness 11.5mm compared to that of wall thickness 10.5mm. When rolling pierced shell of wall thickness 10.5mm, there exist front and back tensions among the third, the fourth and the fifth stands and outline dimension and real roundness of rolled hollow tube is slightly better. However, transverse wall thickness of rolled hollow tube at the bottom of groove is pulled thin obviously.

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.

Research on the Minimum Rolled Thickness of Strip Steel in Cold Tandem Rolling

2014 ◽  
Vol 622-623 ◽  
pp. 993-999
Author(s):  
Shou Min Wu ◽  
Lie Sheng Wei ◽  
Gang Huang
Keyword(s):  
Coulomb Friction ◽  
Production Efficiency ◽  
Field Experiments ◽  
Rolling Force ◽  
Rolling Process ◽  
Force Model ◽  
Constraint Condition ◽  
Steel Rolling ◽  
Strip Steel ◽  
Fully Integrated

In consideration of the zone between rolls and deformed area where friction at roll-sheet interface is lower than predetermined value of Coulomb friction in rolling process of ultrathin strip steel, fully integrated with equipment and process features of cold tandem mills, after a large number of field experiments and theoretical studies, on the basis of the improvement of ultrathin strip steel rolling force model, with the allowable rolling pressure and production efficiency as constraint condition, a new calculated theory about the minimum rolled thickness was put forward. What’s more, the theory will be used in the productive practice of 1220 five-rack cold tandem mills of China. The technique has the value to be further popularized.

scholarly journals Influence of snake rolling on metal flow in hot rolling of aluminum alloy thick plate

2020 ◽  
Vol 21 (5) ◽  
pp. 525
Author(s):  
Pujun Hao ◽  
Jingna Liu
Keyword(s):  
Finite Element ◽  
Aluminium Alloy ◽  
Thick Plate ◽  
Metal Flow ◽  
Element Model ◽  
Rolling Process ◽  
Negative Influence ◽  
Speed Ratio ◽  
Asymmetrical Rolling ◽  
Offset Distance

Most asymmetrical rolling conditions should not appear in regular rolling processes, but for obtaining large deformations inside aluminium alloy thick plates, the asymmetrical rolling process is the most effective method. Snake rolling is adopted for promoting more deformation inside the plates. For exploring the deformation inside an aluminium alloy thick plate, a finite element model for simulating the process of snake rolling is established and the key influence factors are set as initial thickness, speed ratio and offset distance. The results show that deformation inside of the plate increases obviously while the thickness of plate is less than 300 mm after snake rolling. The speed ratio has a positive effect on promoting deformation partly inside of the plate. On the contrary, the offset distance has a negative influence by affecting the exit thickness. A formula for calculating the exit thickness after snake rolling is proposed and validated by data from the finite element models. Thus, snake rolling is suggested to be used in the downstream pass of hot rough rolling considering that the influence of thickness and the offset distance should be controlled in a reasonable range.

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