• Title/Summary/Keyword: Maximum Forging Load

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UBET Analysis on Precision Rib-Web Forgings (리브-웨브형 정밀단조에 관한 상계요소해석)

  • 이종헌;김영호;배원병
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.5
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    • pp.1211-1219
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    • 1995
  • An upper bound elemental technique (UBET) program has been developed to analyze forging load, die-cavity filling and effective strain distribution for flash and flashless forgings. The simulation for flash and flashless forgings are applied axisy mmetric and plane-strain closed-die forging with rib-web type cavity. Inverse triangular and inverse trapezoidal elements are used to analyze flashless forging. The analysis is described for merit of flashless precision forging. Experiments have been carried out with pure plasticine billets at room temperature. Theoretical predictions of the forging load and the flow pattern are in good agreement with experimental results.

A Study on Flashless Non-Axisymmetric Forging (플래시 없는 비축대칭 단조에 관한 연구)

  • Bae, Won-Byong;Kim, Young-Ho;Choi, Jae-Chan;Lee, Jong-Heon;Kim, Dong-Young
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.3
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    • pp.42-52
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    • 1995
  • An UBET(Upper Bound Elemental Techniquel) program has been developed to analyze forging load, die-cavity filling and effective strain distribution for flashless non-axisymmetric forging. To analyze the process easily, it is suggested that the deforma- tion is divided into two different parts. Those are axisymmetric part in corner and plane- strain part in lateral. The total power consumption is minimized through combination of two deformation parts by building block method, form which the upper-bound forging load, the flow pattern, the grid pattern, the velocity distribution and the effective strain are deter- mined. To show the merit of flashless forging, the results of flashless and flash-forging processes are compared through theory and experiment. Experiments have been carried out with plasticine billets at room temperature. The theoretical predictions of the forging load and the flow pattern are in good agrement with the experimental results.

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Forming Analysis and Experiment of Hard to Forming T Shape Aluminum Part (난성형 T형상 알루미늄 부품의 성형공정 해석 및 실험)

  • Jin, Chul-Kyu
    • Journal of the Korean Society of Industry Convergence
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    • v.20 no.2
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    • pp.141-148
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    • 2017
  • A process comprising a hot extrusion process and a warm forging process was designed to form a T-shaped aluminum structural component with a high degree of difficulty by the plastic forming method. A circular cylindrical part was extruded with a hot extrusion process, and then an embossing part was formed with a warm forging process. The formability and the maximum load required for forming were then determined using a forming analysis program. The hot extrusion process was executed at $450^{\circ}C$ under the extrusion speed at 6 mm/s, while the warm forging process was executed at $260^{\circ}C$ under the forging speed at 150 mm/s. For both the processes, a condition by which friction would not be generated between the mold and the material was implemented. The analysis results showed that the load required for hot extrusion was 1,019 tons, while the load required for the warm forging was 534 tons. The T-shaped part was manufactured by using a 1,600 tons capacity press. The graphite lubricant was coated on the mold as well as the material. A forming experiment was performed under the same condition with the analysis condition. The measured values from the load cell were 1,210 tons in the hot extrusion process and 600 tons in the warm forging process.

A Study on the Forming Conditions of a Forging Piston by using the Finite Element Simulation and the Taguchi Method (유한요소해석과 다구찌방법을 이용한 단조피스톤의 성형조건 연구)

  • You, Ho-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.5
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    • pp.1990-1995
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    • 2012
  • This paper presents design methodology to determine the design parameters that affect the manufacture of aluminum forging piston using the FE simulation and the Taguchi method. Maximum forging load is used as the objective function, and preform, material temperature and draft angle are selected as the design parameters. Their combinations are implemented by orthogonal array, and forging load is evaluated through the simulation. From the analytic results of design parameters to minimize the load using signal to noise ratio, their optimal combinations are proposed. The proposed design methodology will be able to help in selecting proper preform among preforms and to be used in determining the optimal combination of the parameters in metal forming process.

A Study on the Improvement of Forming Processes of Valve-Spring Retainer (Valve-Spring Retainer의 성형공정개선에 관한 연구)

  • 오현석;황병복;이호용
    • Transactions of Materials Processing
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    • v.5 no.2
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    • pp.145-155
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    • 1996
  • The conventional five-stage forming processes of the valve-spring retainer are simulated using the rigid-plstiv finite element method. As a design criterion the improved process should satisfy the maximum forging load during processes within the loading limit of the available press and should not induce any geometrical defects. hollow bars are recommended as initial billets to skip the heading and piercing processes. Through various simulations it is found out that the one stage process results in less forging loads and better strain distributions.

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Finite element analysis of eccentric loading in high-velocity impact forging (고속 타격단조시 발생되는 편심부하의 유한요소해석)

  • Yoo, Yo-Han;Yang, Dong-Yol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.10
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    • pp.1589-1597
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    • 1997
  • The high-velocity impact forging process with eccentric loading condition is analyzed using the explicit time integration finite element method. In order to consider the strain hardening, strain rate hardening and thermal softening effects, which are frequently observed in high-velocity deformation phenomena, the Johnson-Cook constitutive model is applied to model the workpiece. It is assumed that the material response of the dies is elastic in the study. As a result of the eccentric loading simulation, it is found that the increase of the eccentric ratio and the allowable tilting angle cause the decrease of the maximum forging load and the blow efficiency, and it is also found that the forging load and the blow efficiency generated in the high-velocity impact forging process with three-dimensional geometry can be obtained efficiently.

Process Planning and Die Design for the Super Hot Forging Product, the Piston Crown Used in Marine Engine (선박엔진용 초대형 열간단조품, 피스톤크라운의 단조공정 및 금형 설계)

  • Hwang, B.C.;Lee, W.H.;Bae, W.B.;Kim, C.
    • Transactions of Materials Processing
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    • v.17 no.8
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    • pp.600-606
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    • 2008
  • In closed-die hot forging, a billet is formed in dies such that the flow of metal from the die cavity is restricted. Some parts can be forged in a single set of dies, whilst others, due to shape complexity and material flow limitations, must be shaped in multi sets of dies. The purpose of a performing operation is to distribute the volume of the parts such that material flow in the finisher dies will be sound. This study focused on the design of preforms, flash thickness and land width by theoretical calculation and finite element analysis, to manufacture the super hot forging product, 70MC type piston crown used in marine engine. The optimal design of preforms by the finite element analysis and the design experiment achieves adequate metal distribution without any defects and guarantees the minimum forming load and fully filling of the cavity of the die for producing the large piston crown. The maximum loads obtained by finite element analysis are compared with the results of experiments. The loads of the analysis have good agreements with those of the experiment. Results obtained using DEFORM-2D enable the designer and manufacturer of super hot forging dies to be more efficient in this field.

A Study on the Optimal Stress Compensation to Dynamic Recrrystallization for the Estimation of Forming Loads (성형하중예측을 위한 재결저분율 보상의 최적조건 도출)

  • 장영원
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.03b
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    • pp.131.1-134
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    • 1999
  • The effect of dynamic recrystallization during hot forming process was implemented to a commercial FEM code by conditioned remeshing and remapping of sate variables. A datum strain for stress compensation was determined as a strain for maximum softening rate and was able to be formulated as a function of critical strain f($\varepsilon$). The validity of remapping criterion was examined by a series of mechanical tests and microstructural observation. The application of suggested datum resulted in better estimation of load-stroke during forging processes.

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Development of Rotary Forging Press with Multi-Rocking Motion (다운동 방식 회전단조기 개발)

  • 이윤우;김소겸;최상수;박준수;김윤배;임성주;윤덕재;김승수;박훈재
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1995.06a
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    • pp.47-54
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    • 1995
  • Rotary forging process has many advantages such as compacting of machine, low price of facilities and good quality of products. The last presented was a technical report about rotary forging press in the 100-ton class, which has the only orbital motion limited to the forming of axisymmetric parts. In this paper, the newly developed rotary forging press is introduced. The maximum capacity of forming load is 280 ton and five locking motion, this is, orbital, straight pivot, spiral and two kinds of clover can be available. This machine consists of transmission, double eccentric bush, rocking shaft, die set and hydraulic unit. Especially, the supports of rocking shaft and double eccentric bush are so crucial that hydrostatic bearings are adopted. Finally, it is expected that the technical know-how obtained in this research can be applied to the manufacturing of the another machine with large capacity.

A Study on the Determination of Initial Biller for Axisymmetric Cold Forging Products Using Neural Networks (신경망을 이용한 축대칭 냉간 단조품의 초기 소재 결정에 관한 연구)

  • 김영호;배원병;박종옥
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.217-222
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    • 1994
  • This paper describes the determination of optimal initial billet size for axisymmetric cold forging products using neural networks. The determination of optimal initial billet size is very important in forging design and forming sequence design, because the result of such designs and forming load can be different by variable initial billet sizes. The forming difficulty has been defined as the degree of difficulty in forming by 3 process ' forward extrusion, backward extrusion and upsetting. By neural networks a forming difficulty can be determined with the ratio of shape and forming process. From the graph of maximum, minimum, and average forming difficulties by variable billet sizes, the optimal billet size can be determined. The initial billets of a solid part and a hollow part whichwas determined by this study are compared with the sequence drawing generated by the one of forming sequence design system.

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