Vertical Horizontal Rolling Process Research Articles

Short Stroke Control Model for Improving Width Precision at Head and Tail of Slab in Hot Vertical–Horizontal Rolling Process

The objectives of this study were to analyze the width changes about the head and tail ends of the slab occurring during vertical–horizontal rolling using finite element (FE) analysis, and to derive an appropriate short stroke control (SSC) model for vertical–horizontal rolling based on the results of analyses. The relationship between the process variables and slab deformation about the head and tail ends, including width shrinkage and length of width shrinkage, was derived using the linear regression method. From considering the amount of slab deformation, an advanced SSC model for vertical–horizontal rolling process has been developed. The proposed SSC model was verified via an FE simulation. Vertical rolling simulations were performed using the roll gap that was calculated via the respective SSC model for each steel slab. Horizontal rolling simulations were also conducted. Cropping lengths about the head and tail ends that were regulated by width control standards of the specific work site were compared.

Coupled Thermo-Mechanical FEM Simulation of Multi-Pass Vertical-Horizontal Rolling Process

The governing equations and the finite element model for the coupled thermo-mechanical multi-pass vertical-horizontal rolling process of a zircaloy strip are established. Considering the temperature-dependent and strain rate-dependent constitutive relation of zircaloy, the numerical simulation of the three-pass V-H rolling process is realized by the coupled thermo-mechanical dynamic explicit finite element method. The computational results such as the plastic deformation, the size variations and the temperature variations in three passes are discussed. The research results indicate that edging by vertical roller benefits improving the sizes of the strip and the temperature variations are rather obvious during the three-pass hot rolling process. The research provides experience and foundations for the FEM simulation of the hot rolling process of composite slabs for nuclear fuel elements.

Research and Design of Polynomial Short Stroke Control Curve for Roughing Process

A numerical simulation model for vertical-horizontal rolling process in roughing trains is built according to 3-D rigid-plastic finite element method (FEM), which is validated by comparing the simulation results with measured ones of industrial production. The principle of width deviation appearing on head and tail of slab is investigated by the finite element (FE) simulations. A new polynomial short stroke control (SSC) model is developed based on the comprehensive simulation results and the analyzed results show that, at the aspect of width control, the new SSC model is more effective than the two line one.

3-D Finite Element Simulation of the Vertical-Horizontal Rolling Process

In order to investigate the deformation behavior of a plate during a vertical-horizontal rolling process, a thermo-mechanical coupling analysis is carried out by three-dimensional (3-D) rigid-plastic FEM to simulate the process. The metal flow and the shape evolution of the plate are focused during this investigation. The thickness and the width of the plate agree well with the measured values.

Head and Tail Shape Control in Vertical-Horizontal Rolling Process by FEM

Using 3D rigid-plastic finite element method (FEM), a numerical simulation model for nonsteady state vertical-horizontal rolling process in roughing trains was built and was validated by comparing the simulated values with experimental ones of width and shape of the stock ends. According to certain 2050 roughing processing technologies, the short shape control (SSC) of the stock ends was investigated using the model. Based on the simulated results, a new SSC model was developed. The analyzed results showed that the new SSC model is effective in improving the shape of the stock ends.

Analysis of Crack Tip Stress of Transversal Crack on Slab Corner During Vertical-Horizontal Rolling Process by FEM

Behavior of transversal crack notched on slab corner during vertical-horizontal rolling process was simulated by FEM. The crack tip stress in the whole rolling process was obtained. Influences of the friction coefficient, the initial crack size, the edger roll profile, and the groove fillet radii of grooved edger roll on crack tip stress were analyzed. For vertical rolling, the tension stress appears at crack tip near the slab top surface and the compression stress appears at crack tip near the slab side surface for the flat edger roll; however, the compression stress appears at crack tip near the slab top surface and the tension stress appears at crack tip near the slab side surface in the exit stage for the grooved edger roll. For horizontal rolling, the tension stress appears at crack tip just at the exit stage for the flat edger roll, and the tension stress appears in whole rolling stage; the tension stress value near the slab side surface is much larger than that near the slab top surface for the grooved edger roll.

FEM analysis for V–H rolling process by updating geometric method

Three passes of slab rolling during vertical–horizontal rolling process were simulated with explicit dynamic FEM by updating geometric method. Simulation model of the next pass was built when the rolling geometry model was updated after previous pass was finished, changing roll gap, material attribution and boundary conditions. The calculated results of the slab shape are in good agreement with the experimental ones. It is shown that the explicit dynamic FEM and updating geometric method can be used effectively to analyze the multi-passes of V–H rolling process.

Explicit Dynamic FEM Analysis of Multipass Vertical-Horizontal Rolling

Three passes of plate rolling during vertical-horizontal rolling process are simulated with explicit dynamic finite element method and updating geometric method. The equivalent strain and stress fields, and shape change at the head and tail of slab during rolling are obtained. The calculated result of the shape at the head and tail of slab is in good agreement with the measured one. The explicit dynamic finite element method and updating geometric method can be used effectively to analyze the multipass vertical-horizontal (V-H) rolling process.

열간 압연에서 2단 사이징 프레스 금형에 의한 슬래브의 변형거동 예측

Extensive width reduction of slabs is an important technology for achieving continuous production between the steelmaking and hot rolling processes. However, the vertical horizontal rolling process has many disadvantages, e.g., large width deviations and less efficient width reduction. This study was carried out to investigate the deformation of slab by sizing press with two steps die. To do it, dog-bone and camber are discussed in width sizing process considering the deformation behavior according to the deviation of anvil velocity and the deviation of initial slab temperature. In this paper, the various causes of the sizing press phenomena are mentioned for the purpose of understanding of rolling conditions. As a result, the optimal anvil shape having a minimum-forming load is obtained by FE-simulation and ANN.

Three-dimensional modelling of the vertical–horizontal rolling process

This paper discusses the utilisation of the slightly compressible finite element formulation to the numerical analysis of the vertical–horizontal rolling process. The first part of the paper details the basis of the plasticity theory for slightly compressible materials and presents an overview of its numerical implementation. Of particular interest in vertical–horizontal rolling are topics related to the prediction of the dog-bone shape when using a Eulerian formulation, the treatment of the frictional boundary conditions along the three-dimensional roll–workpiece contact interfaces and the modelling of the material streamlines within the plastically deforming region. The second part of the paper presents a comparison between theoretical predictions obtained by means of a special purpose computer program developed under the proposed approach and experimental results taken from the literature. Assessment is made in terms of the cross-sectional shapes, roll separating force and torque.

Analysis of the non-steady state vertical–horizontal rolling process in roughing trains by the three-dimensional finite element method

The vertical–horizontal rolling process is often used to accomplish width reduction so as to provide a synchronising operation between the continuous slab casting and hot rolling processes. Numerical simulation of the non-steady state deformation behaviour around the head and tail ends during this process is made by the full three-dimensional rigid–plastic finite element method. An explanation is provided in the theory for the ‘thin element technique’ at the inlet surface of velocity discontinuity. To deal with the interpolation of friction within a surface of an element contacting partly with the roll, a new term, so-called ‘pseudo shape function’, is presented and a related new equation formula is deduced. The calculated shape of the slab edge, the separating force and the rolling torque are consistent with those measured experimental ones for the model material lead.

Three-dimensional thermo-mechanical finite element simulation of the vertical–horizontal rolling process

This paper presents a three-dimensional thermo-mechanical analysis of the vertical–horizontal rolling process utilised in the large width reductions of slabs in hot strip mills. The theoretical analysis is based on the utilisation of the finite element flow formulation to characterise the material flow, to predict the distribution of temperature and to estimate the roll separating force. The numerical predictions were verified by metal experiments performed at the hot strip mill unit of Bao Steels (China). The experimental work consisted of the monitorisation of the surface temperature and of the roll separating force for several rolled slabs. The theoretical distribution of stress obtained from the numerical simulation of the process is also analysed.

A three-dimensional finite element simulation of the vertical–horizontal rolling process in the width reduction of slab

A thermal coupling analysis is carried out by the full three-dimensional rigid–plastic finite element method to simulate vertical–horizontal rolling process during width reduction in the roughing stands of a hot strip mill. The slab shape, the spread and temperature as calculated are in good agreement with the experimental results in production mills, and the sectional distribution of temperature is given.

Simulation of vertical-horizontal rolling process during width reduction by full three-dimensional rigid-plastic finite element method

Vertical-horizontal (V-H) rolling is an important process during width reduction in the roughing stand of hot strip mill. A simulation of steady-state V-H rolling was carried out by the full three-dimensional rigid-plastic finite element method (3D RPFEM). To consider the shear work rate and cope with a singular point, an extremely thin array of elements was attached before the entry of the roll. The slab shape, the spread, the separating force, and the rolling torque calculated were in good agreement with the experimental values.