• Title/Summary/Keyword: Shape Rolling

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Effect of Rolling Speed on the Exit Cross Sectional Shape in Rod Rolling Process

  • Lee, Young-Seog
    • International Journal of Precision Engineering and Manufacturing
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    • v.8 no.1
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    • pp.27-31
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    • 2007
  • A rolling speed dependent spread model is proposed for predicting the exit cross sectional shape in oval-round (or round-oval) pass rod rolling process when the rolling speed is very high. The effect of rolling speed on the exit cross sectional shape is measured by performing a four-pass continuous high speed (${\sim}80m/s$) rod rolling test and is described in terms of the spread correction parameter. The validity of the model is examined by applying it to rod rolling process at POSCO No.3 Rod Mill. The cross sectional shapes of workpiece predicted by the proposed model coupled with the surface profile prediction $method^{6}$ are in good agreement with those obtained experimentally.

Effect of lubrication on the evolution of strain states in AA 5052 sheet during shape rolling (알루미늄 5052 합금 판재의 이형 압연 시 변형률 상태에 미치는 윤활의 영향)

  • Park, E.S.;Hwang, K.C.;Huh, M.Y.;Kim, H.J.;Bae, J.C.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.05a
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    • pp.256-259
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    • 2009
  • In order to investigate the effect of strain states attributed to the lubrication during shape rolling, shape rolling for V-sectioned sheets was carried out with and without lubrication. The evolution of strain states during shape rolling was studied by three-dimensional finite element method (FEM). Shape rolling with and without lubrication produces shape-rolled samples in fairly similar outer shapes, since the distribution of normal strain components is nearly independent of the lubrication condition. In contrast, the distribution of shear strain components strongly depends on the lubrication condition.

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Shape Prediction in Eulerian Analysis of Steady State Shape Rolling (정상상태 형상압연의 오일러리안 해석에서 형상 예측)

  • 이용신
    • Transactions of Materials Processing
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    • v.10 no.7
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    • pp.579-583
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    • 2001
  • Shape changes of a workpiece in an Eulerian Finite Element analysis for the steady state, three-roll-stand shape rolling are modelled. Although an Eulerian analysis has many advantages for the steady state rolling problems, it necessitates an assumption about the unknown shape of the control volume. In almost all cases, the assumed control volume does not match the final shape and the control volume should be updated. This update can be accomplished by performing a free surface correction. The final shape of a material point, which has a spherical shape at the inlet, can be also predicted by integrating a deformation gradient along a stream line. Analyses of three-roll-stand shape rolling are performed and the results are discussed in detail.

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Shape Prediction in Eulerian Analysis of Three-Roll-Stand Shape Rolling (Three-Ro II-Stand 형상압연의 오일러리안 해석에서 형상예측)

  • 이용신;나경환
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.328-331
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    • 2001
  • Shape changes of a workpiece in an Eulerian Finite Element analysis for the steady state. three-roll-stand shape rolling are modelled. Although an Eulerian analysis has many advantages for the steady state rolling problems, it necessitates an assumption about the unknown shape of the control volume. In almost all cases. the assumed control volume does not match the final shape and the control volume should be updated. This update can be accomplished by performing a free surface correction. The final shape of a material point, which has a spherical shape at the inlet, can be also predicted by integrating a deformation gradient along a stream line. Analyses of three-roll-stand shape rolling is in detail examined.

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HIGH LEVEL SHAPE CONTROL FOR PLATE ROLLING BY USING PAIR CROSS MILL (후판압연에서의 형상제어의 고도화)

  • 김영헌;남구원
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.08a
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    • pp.447-451
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    • 1999
  • The plate crown and shape control of plate rolling has become important to obtain not only improved quality but also better yield of products and higher work ratio of rolling. Therefore, the development of a new plate crown and shape control system has been demanded in plate rolling mill. The 3rd Plate Rolling Works of POSCO introduced the new unique system

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Simulation of square-to-oval single pass rolling using a computationally effective finite and slab element method

  • 이상매;김낙수
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1991.04a
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    • pp.237-242
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    • 1991
  • Shape rolling has been studied experimentally by many researchers. As large numbers of process variables are involved and the material flow is difficult to analyze in shape rolling, the use of numerical techniques as an engineering tool becomes extremely attractive. The first numerical approach to the three-dimensional plastic deformation of rolling was to investigate side spread in flat rolling. Oh and Kobayashi conducted a pioneering study in this field by applying an extremum principle for rigid, perfectlyplastic materials combined with the numerical computation. Since then, several other researchers have used three-dimensional finite element method for analysing spread in rolling . In this investigation of shaperolling al the computer simulations of shape rolling were conducted using TASKS. To verify the predictive capabilities of TASKS the first example chosen was square-to-round shape rolling

A Fuzzy Shape Control Method for the Stainless Steel at the Cold Rolling Process (스테인리스 냉연공정에서 퍼지 형상제어)

  • Hur, Yone-Gi
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.10
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    • pp.1062-1070
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    • 2009
  • The strip shape for the stainless steel process has made an issue of the strip quality, and hence the shape control method is developed at the Sendzimir rolling mill (ZRM). ZRM is a stainless cold rolling mill and has actuators for the shape control. They are first intermediate rolls and top crown rolls, which are controlled horizontally and vertically, respectively. The shape control of the stainless steel rolling process has difficulty in obtaining the symmetrical shape. The objective of the shape control is to minimize the shape deviation and to maintain stable state, which keeps symmetrical shape pattern in the lateral direction. The method of the shape recognition employs a least squares method and neural network. The shape deviation is the difference between the target shape and actual shape and is controlled by the fuzzy shape control. The fuzzy shape control using operator's informative knowledge is proposed in this paper. The experiments are carried out online for various stainless materials and sizes. The productivity of the rolling process has increased from 9.0 to 9.4 tons per hour.

Study on the Irregular Shape Rolling Process (비대칭 형상 압연 공정에 대한 연구)

  • 김용철;김동진;김병민
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.08a
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    • pp.98-106
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    • 1999
  • In this study cold rolling process for the irregular cross-sectional shape has been investigated. The product analyzed in present study is the steel cutter, which is frequently used to cut the desired shape on leather. Because steel cutter always has a irregular cross-section, after rolling process the workpiece is severely bended to every direction. The bending of the workpiece affects the processed performed after rolling such as heat treatment and grinding, then that of the workpiece becomes more severe. In this study, therefore, to prevent the bending of the workpiece to the left and right sides. rigid-plastic finite element method has been utilized and in order to find optimal roll geometry rapidly, one dimensional equal interval search technique has been also introduced. By using both rigid plastic finite element method and optimum technique, cold rolling process for the irregular cross-sectional shape has been successfully investigated.

Study of Edge Crack Growth According to Rolling Condition in Cold Rolling (냉간압연공정에서 공정변수에 따른 엣지 크랙 성장에 관한 연구)

  • Cui, X.Z.;Lee, S.H.;Lee, S.J.;Lee, J.B.;Kim, B.M.
    • Transactions of Materials Processing
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    • v.18 no.5
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    • pp.377-384
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    • 2009
  • The shape of edge cracking in rolling process generally occurred "V" shape. This cracking is successively generated at width edge of strip. The edge cracking is developed to center of strip during rolling process. In the results, the strip is occurred fracture, and the productivity is gone down because of the extensive production time. Accordingly, we need to control crack propagation during rolling process. But, the control of cracking is very difficult in rolling process. Previously the studies of edge cracking were mainly performed on hot rolling process. In this paper, the shape of the edge cracking in rolling was estimated according to process conditions such as initial edge crack size, reduction ratio and tension using FE-simulation and the simplicity experiments on cold rolling process.

The Analysis of H-Shape Rolling by the Finite Element Method (유한요소법에 의한 H형강 압연공정의 해석)

  • 신현우;김낙수;박종진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.5
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    • pp.1095-1105
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    • 1993
  • Shape rolling processes to produce H-section beams are numerically simulated by the simplified three-dimensional finite element method. The 2-dimensional finite element method, used for the generalized plane strain condition, is combined with the slab method. Computer simulation results of the 19-passes in H-section beam rolling in practice include the grid distortions, the cross-sectional area changes, the roll separating forces, and the roll torques. Also, the amount of side spread can be found during the multi-pass rolling simulations. The finite element mesh system is remeshed with I-DEAS whenever the billet distorts severely. This study would contribute to CAD/CAM of shape rolling process through the optimal roll pass schedule.