Study on Minimum Rollable Thickness in Asymmetrical Rolling

2021 ◽  
Author(s):  
Ji Wang ◽  
Xianghua Liu
Keyword(s):  
Shear Zone ◽  
Deformation Zone ◽  
Rolling Force ◽  
Slip Zone ◽  
Speed Ratio ◽  
Slab Method ◽  
Roll Speed ◽  
Asymmetrical Rolling ◽  
New Model ◽  
Good Agreement

Abstract A new model for the asymmetrical rolling is proposed to calculate the minimum rollable thickness simply and fast by the slab method. The calculation formulas of the rolling pressure, the rolling force, the critical roll speed ratio and the critical front tension under different deformation zone configurations are proposed, and the deformation zone configuration - rolling parameters relationship diagram is given and analyzed. The results show that the minimum rollable thickness can be reached when the rolling parameters keep the deformation zone configuration as cross-shear zone + backward-slip zone (C+B) or all cross-shear zone (AC). The calculation formulas of the minimum rollable thickness and the required rolling parameters for different deformation zone configurations are proposed respectively. The calculated value is in good agreement with the experimental results.

The analytic study on the heavy steel plate snake rolling with the different roll diameters

2019 ◽  
Vol 116 (4) ◽  
pp. 402 ◽  
Author(s):  
Qing-cheng Meng ◽  
Lian-yun Jiang ◽  
Li-feng Ma ◽  
Jun-yi Lei
Keyword(s):  
Shear Zone ◽  
Deformation Zone ◽  
Steel Plate ◽  
Rolling Force ◽  
Slip Zone ◽  
Mechanical Parameters ◽  
Rolling Method ◽  
Rolling Torque ◽  
Inner Region ◽  
Rolling Deformation

The deformation in the inner region along the thickness of the heavy steel plate can be improved by snake rolling method. Then the microstructure and property will be refined and the crack in the inner region may be avoided. So the in-depth research on snake rolling method mechanics parameter modeling should be conducted to guide production. The rolling deformation zone will be divided into back slip zone, cross shear zone, front slip zone and reverse deflection zone according to the direction of the friction during the snake rolling process. The four zones may not exist at the same time. The boundary conditions of existence of the back slip zone, cross shear zone and front slip zone were established by calculating the position of neutral point by a special method. The calculating models which were used to calculate the snake rolling mechanical parameters including the rolling force and rolling torque were setup. The calculated models of unit compressive pressure in the four zones were setup by the slab method, and at this basis, the accurate calculating models of the rolling force and rolling torque were setup according to the composition of the rolling deformation zone and the boundary condition. The mechanical parameters were calculated by the analytic method and the numerical method, and the relative deviation is less than 5% which can satisfy the industrial requirement. The present analytical model can predict the characteristics during snake rolling easily and quickly and it is also suitable for online control applications.

scholarly journals A fast calculation method of large-cylinder asymmetrical rolling force considering shear effect

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401881952 ◽  
Author(s):  
Suwen Chen ◽  
Jie Li ◽  
Xingxing Yuan ◽  
Dapeng Gu ◽  
Hongmin Liu
Keyword(s):  
Shear Zone ◽  
Rolling Force ◽  
Speed Ratio ◽  
Shear Stresses ◽  
Shear Effect ◽  
Asymmetrical Rolling ◽  
Online Application ◽  
Vertical Side ◽  
Large Cylinder ◽  
Roll Gap

An analytical model for large-cylinder asymmetrical rolling is proposed based on an improved slab method, which can predict the rolling force more quickly. In this method, uneven normal and shear stresses acting on the vertical side are supposed. In the solution, the upper and lower contact lengths are different, and the roll gap is divided into four slabs. Moreover, the effects of the rolling parameters such as roll speed ratio, roll radius, exit thickness, and radius of cylinder on the rolling force and cross-shear zone ratio are investigated. The cross-shear zone ratio, which means the shear effect, is a key parameter in reducing rolling force and microstructure refinement. This method is conducted with the experimental and finite element verification, and good agreement has been found. It should be noted that the calculation result can be obtained rapidly and easily by this proposed model. Therefore, the present model is suitable for online application.

Analysis of snake rolling force and torque with changes of thickness depending on unequal roll radii based on pure aluminum experiments

2016 ◽  
Vol 231 (1) ◽  
pp. 161-174 ◽  
Author(s):  
HY Wang ◽  
ZH Wang ◽  
DH Zhang ◽  
DW Zhao
Keyword(s):  
Rolling Force ◽  
Pure Aluminum ◽  
Speed Ratio ◽  
Roll Speed ◽  
Equivalent Radius ◽  
Roll Torque ◽  
Offset Distance ◽  
Proposed Model ◽  
Theoretical Results ◽  
Good Agreement

An analytical model, in which unequal radii are replaced with an equivalent radius, is creatively proposed to predict the rolling force and roll torque in general case of snake rolling. With the model, the effects of roll radius ratio, roll speed ratio, offset distance between rolls, reduction and friction coefficient on rolling forces in hot snake rolling of aluminum alloy are obtained. Also, the thicknesses of slab are investigated in different zones, which firstly propose the changes of thickness during snake rolling. Owing to the good agreement with the results measured in experiments and calculated by finite element method and other traditional models, those calculated by the proposed model are verified. The proposed model can be used to predict more accurate theoretical results for snake rolling force and torque.

The mechanical parameters modeling of heavy steel plate snake/gradient temperature rolling with the same roll diameters

2020 ◽  
Vol 117 (3) ◽  
pp. 301
Author(s):  
Lian-Yun Jiang ◽  
Tao Zhen ◽  
Guo Yuan ◽  
Jin-Bo Huang ◽  
Yao-Yu Wei ◽  
...  
Keyword(s):  
Shear Zone ◽  
Steel Plate ◽  
Rolling Force ◽  
Slip Zone ◽  
Analytic Model ◽  
Mechanical Parameters ◽  
Ansys Software ◽  
Relative Deviation ◽  
Maximum Relative Deviation ◽  
Rolling Torque

The grains in the center of the heavy steel plate can be refined by the snake/gradient temperature rolling, and the deformation penetration, the microstructure, and the properties of the steel plate will be improved. The existing rolling mechanical models are not suitable for the snake/gradient temperature rolling, so it is necessary to establish the mechanical parameters model of the snake/gradient temperature rolling to instruct production. The yield criterion of rolled material was modified based on the idea of equivalent flow stress. The element stress analyses were carried out based on the uniform normal stress and nonuniform shear stress in the vertical sides of each slab. Then the equilibrium equation of the unit pressure based on the slab method was established on this basis. The deformation region was divided into three layers (the top layer, the bottom layer, and the central layer) and maximum four zones (back slip zone, front slip zone, cross shear zone, and reverse deflection zone) according to the temperature distribution and position of the neutral point, and then the 12 zones were formed during the snake/gradient temperature rolling. The boundary conditions of the existence of the back slip zone, the front slip zone, and the cross shear zone were established according to the relationship between the threading angle and the neutral angle. The accurate mechanical parameters model of the rolling force and rolling torque of the snake/gradient temperature rolling with the same roll diameters was set up on this basis. The ANSYS software has been used in the rolling process simulation by many scholars, and the calculating precision has been verified. So the rolling processes were simulated by the ANSYS software to validate the model precision. The results show that the maximum relative deviation of the rolling force analytic model is less than 7% compared with the numerical method, and the maximum relative deviation of the rolling torque analytic model is less than 11% compared with the measured results. The mechanical parameters model can accurately predict the rolling force and rolling torque during the snake/gradient temperature rolling with the same roll diameters, so as to provide a theoretical basis for the design of rolling mill and the setup of the process parameters.

Calculation of Rolling Force of 3700mm Cylindrical Shell Rolling Mill

2012 ◽  
Vol 572 ◽  
pp. 19-24
Author(s):  
Su Wen Chen ◽  
Hong Min Liu ◽  
Yan Peng ◽  
Jian Liang Sun ◽  
Bin Bin Sun
Keyword(s):  
Cylindrical Shell ◽  
Deformation Zone ◽  
Rolling Mill ◽  
Rolling Force ◽  
Metal Flow ◽  
Force Model ◽  
Equilibrium Equations ◽  
Stress Equilibrium ◽  
Slip Area ◽  
Good Agreement

Rolling force is an important technological parameter in designing of the 3700mm cylindrical shell rolling mill. Due to the characteristics of double driving rolls and asynchronous rolling of 3700 mm cylindrical shell rolling mill, the force analysis of the deformation zone is complex. In this study, an analytic method was used to calculate the rolling force. The deformation zone was divided into the forward slip area, the backward slip area and the rub rolling area on the basis of metal flow velocity. The stress equilibrium equations of each area were built. Then the rolling force model of the 3700mm cylindrical shell rolling mill was built and solved, according to the boundary conditions. At the same time, in order to verify the validity of the analysis, the calculated values were compared with the measured in the spot. They have a good agreement, which indicates the calculation accuracy of the model could meet the industry requirements.

scholarly journals The Stationary Concentrated Vortex Model

Climate ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 39
Author(s):  
Oleg Onishchenko ◽  
Viktor Fedun ◽  
Wendell Horton ◽  
Oleg Pokhotelov ◽  
Natalia Astafieva ◽  
...  
Keyword(s):  
Vortex Structure ◽  
Radial Direction ◽  
Symmetry Axis ◽  
Outer Part ◽  
Vertical Direction ◽  
Axially Symmetric ◽  
New Model ◽  
Vortex Model ◽  
Axis Of Symmetry ◽  
Good Agreement

A new model of an axially-symmetric stationary concentrated vortex for an inviscid incompressible flow is presented as an exact solution of the Euler equations. In this new model, the vortex is exponentially localised, not only in the radial direction, but also in height. This new model of stationary concentrated vortex arises when the radial flow, which concentrates vorticity in a narrow column around the axis of symmetry, is balanced by vortex advection along the symmetry axis. Unlike previous models, vortex velocity, vorticity and pressure are characterised not only by a characteristic vortex radius, but also by a characteristic vortex height. The vortex structure in the radial direction has two distinct regions defined by the internal and external parts: in the inner part the vortex flow is directed upward, and in the outer part it is downward. The vortex structure in the vertical direction can be divided into the bottom and top regions. At the bottom of the vortex the flow is centripetal and at the top it is centrifugal. Furthermore, at the top of the vortex the previously ascending fluid starts to descend. It is shown that this new model of a vortex is in good agreement with the results of field observations of dust vortices in the Earth’s atmosphere.

scholarly journals Thermal conductivity of unsaturated clay-rocks

2010 ◽  
Vol 14 (1) ◽  
pp. 91-98 ◽  
Author(s):  
D. Jougnot ◽  
A. Revil
Keyword(s):  
Thermal Conductivity ◽  
Porous Material ◽  
Solid Phase ◽  
Model Parameters ◽  
Electrical Parameters ◽  
New Model ◽  
Unsaturated Clay ◽  
Unsaturated Porous Material ◽  
Clay Rocks ◽  
Good Agreement

Abstract. The parameters used to describe the electrical conductivity of a porous material can be used to describe also its thermal conductivity. A new relationship is developed to connect the thermal conductivity of an unsaturated porous material to the thermal conductivity of the different phases of the composite, and two electrical parameters called the first and second Archie's exponents. A good agreement is obtained between the new model and thermal conductivity measurements performed using packs of glass beads and core samples of the Callovo-Oxfordian clay-rocks at different saturations of the water phase. We showed that the three model parameters optimised to fit the new model against experimental data (namely the thermal conductivity of the solid phase and the two Archie's exponents) are consistent with independent estimates. We also observed that the anisotropy of the effective thermal conductivity of the Callovo-Oxfordian clay-rock was mainly due to the anisotropy of the thermal conductivity of the solid phase.

DYNAMIC SIMULATION OF THE TAILING PROCESS IN HOT FINISHING MILL

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5661-5666
Author(s):  
SHINIL KIM ◽  
CHENG LU ◽  
XIAOZHONG DU ◽  
ANH KIET TIEU
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Tensile Stress ◽  
Deformation Behavior ◽  
Speed Ratio ◽  
Roll Speed ◽  
Dynamic Finite Element ◽  
Finishing Mill ◽  
Explicit Dynamic ◽  
Method Model

In this paper an explicit dynamic finite element method model has been developed to investigate the strip deformation behavior between two adjacent stands in hot finishing mill. The effect of the roll speed ratio of second stand to first stand on tension and the tailing behavior of the strip has been discussed in details. It has been found that the strip accumulation occurs if the roll speed ratio is small. The tensile stress increases with the roll speed ratio. During the tailing process the accumulated strip caused by the small roll speed ratios knocks onto the roll, while the swing of the strip tail occurs for the large roll speed ratios and it strikes the roll as well. Both tailing phenomena will result in the strip tail pincher or roll damage in the real operation.

scholarly journals Contact angle of water on iron ore fines: Measurement and analysis

2015 ◽  
Vol 51 (1) ◽  
pp. 33-40 ◽  
Author(s):  
X.B. Huang ◽  
X X.W. ◽  
J.J. Song ◽  
C.G. Bai ◽  
R.D. Zhang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Iron Ore ◽  
Contact Angles ◽  
Physical Parameters ◽  
Iron Ores ◽  
New Model ◽  
Pressure Method ◽  
Measurement And Analysis ◽  
Iron Ore Fines ◽  
Good Agreement

The relative contact angle (?RCA) for seven iron ore fines was measured by using Washburn Osmotic Pressure method under laboratory conditions. By choosing cyclohexane as the reference that can perfectly wet iron ore particles, the relative contact angles were measured and varied from 57? to 73?. With the volume % of goethite (?G) as the variable, a new model for relative contact angle was developed. The expected relative contact angle for pure goethite is about 56?, while that for goethite free samples is about 77?. Physical properties, such as surface morphology (SMI) and pore volume (Vpore) can influence the relative contact angle. The ?G can be expressed as a function of SMI and VPore. Thus, we inferred that the relative contact angle is a function of ?G for the iron ores used. The measured relative contact angles were found to be in good agreement (Radj 2 >0.97) with the calculated ones based on the research from Iveson, et al. (2004). Comparing with the model developed by Iveson et al.(2004), the new model for contact angle proposed in this paper is similar, but more detailed with two meaningful physical parameters. The modification of physicochemical properties on iron ores would be another topic in the further study on granulation.

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