• Title/Summary/Keyword: Ring Forging

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Process Design on Fabrication of Large Sized Ring by Mandrel Forging of Hollow Cast Ingot (중공 잉곳을 이용한 대형 링 단조품 제조공정 설계 연구)

  • Lee, S.U.;Lee, Y.S.;Lee, M.W.;Lee, D.H.;Kim, S.S.
    • Transactions of Materials Processing
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    • v.19 no.6
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    • pp.329-336
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    • 2010
  • Ring forging process is more appropriate for high-length and thin walled ring, because it utilizes the forging press and hence does not require heavy-duty ring rolling mill. Although ring forging process is very simple and economic for facilities, the process is not efficient because of multi-forging-step and low material utilization. An effective ring forging process is developed using a hollow ingot. When a hollow ingot is used with a workpiece, the ingot can be forged into a final ring without multi-stage pre-forging process, such as, cogging, upsetting, and piercing, etc.. Finally it has advantages of the material utilization and process improvement because a few reheating and forging process are not necessary to make workpiece for ring forging. The important design variables are the applied plastic deformation energy to eliminate cast structure and make uniform properties. In this study, the mechanical properties after forging of hollow cast ingot were investigated from the experiment using circumferential sectional model. Also, the effects of process variables were studied by FEM simulation on the basis of thermo-visco-plastic constitutive equation. Applied strain is different at each position in length direction because diameter of hollow ingot is different in length direction. The different strain distribution become into a narrow gap by additional plastic deformation during diameter extension process.

Study on the Optimum Design of the Insert Ring and Shrunk Ring of the Cold Forging Die for an Automotive Wheel Nut (자동차 휠 너트용 냉간단조 금형에서 인서트링과 보강링의 최적 설계에 관한 연구)

  • Lee, K.S.;Kim, G.Y;Ahn, Y.S.
    • Transactions of Materials Processing
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    • v.27 no.3
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    • pp.165-170
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    • 2018
  • In order to increase the lifetimes of cold forging dies, insert rings are generally used. In this study, an insert ring and shrunk ring of the flange upsetting die were designed for the cold forging of an automotive wheel nut. The Stress distribution occurring in the die during forging was simulated using a commercial finite element analyzing program. The effects of the fitting interference and inclined angle of the insert ring on the compressive stress of the die inside were also investigated. The simulated data were compared with the real lifetimes of the forging dies. The maximum compressive stress acting on the edge of a forging die should have the most influence on die lifetime, an idea which could help develop the die design with the longest lifetime. The design of the most optimal forging die with the longest lifetime is made possible by analyzing the maximum inner pressure and principal stress between the shrunk ring and insert ring.

A Door Frame for Wind Turbine Towers Using Open-Die Forging and Ring-Rolling Method (열간자유단조와 링롤링공법을 이용한 풍력발전기용 도아프레임 개발)

  • Kwon, Yong Chul;Kang, Jong Hun;Kim, Sang Sik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.7
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    • pp.721-727
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    • 2015
  • The mechanical components for wind turbines are mainly manufactured using open-die forging. This research introduces an advanced forging method to produce the door frame of the tubular wind turbine tower. The advantages of this new forging method are an increase in the raw material utilization ratio and a reduction in energy cost. In the conventional method, the door frame is hot forged with a hydraulic press and amounts of material are machined out because of the shape difference between the forged and final machine products. The proposed forging method is composed of hot forging and ring rolling processes to increase the material utilization ratio. The effectiveness of this new forging method is deeply related to the ring rolled blank dimension before the final forging. To get the optimal ring rolled blank, forged shape prediction using the finite element analysis method was applied. The forged dimensions produced by the new forging method were verified through the first article production.

A Study on the Non-Axisymmetric Closed-Die Ring Forging (비축대칭 형상의 밀폐형 링 단조에 관한 연구)

  • 배원병;김영호;이종헌;이원희
    • Transactions of Materials Processing
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    • v.3 no.2
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    • pp.202-214
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    • 1994
  • An upper bound elemental technique(UBET) is applied to predict the forging load and die-cavity filling for non-axisymmetric ring forging. In order to analyze the process easily, it is suggested that the finial product is divided into three different deformation regions. That is axisymmetric part in corner, lateral plane-strain part and shear deformation on boundaries between them. the place-strain and axisymmetric part are combinded by building block method. Also the total energy is computered through combination of three deformation part. Experiments have been carried out with pure plasticine billets at room temperature. The theoretical predictions of the forging load and the flow pattern are in good agreement with the experimental results.

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A Study on Non-Axisymmetric Ring Forging Using UBET (UBET를 이용한 비축대칭 링 단조에 관한 연구)

  • 배원경;김영호;이종헌;이원희
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1994.03a
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    • pp.63-70
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    • 1994
  • An upper bound elemental technique(UBET) is applied to predict forging load and die-cavity filling for non-axisymmetric ring forging. The finial product is divided into three different deformation regions. That is axisymmetric part in corner, lateral plane-strain part and shear deformation on boundaries between them. The plane-strain and axisymmetric part are combinded by building block method. Also the total energy is computered through combination of three deformation part. Experiments have been carried out with pure plasticine billets at room temperature. The theoretical predictions of the forging load and the flow pattern are in good agreement with the experimental results.

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Development of Outer Support Ring using Complex Forging Processes (복합단조 공정을 적용한 Outer Support Ring 개발)

  • Ju, Won Hong;Park, Sung-young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.4
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    • pp.653-659
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    • 2017
  • In this study, the complex forging process of an outer support ring was developed and the prototype was manufactured. The current process, hot forging and MCT machining, has a disadvantage of excessive material removal rates and longer machining hours. To overcome this disadvantage, a general shape is given through hot forging and the precision is achieved through cold forging. The complex forging process was developed with the minimal machining process. Forging analysis was carried out to design a forging process using the commercial program, Deform-3D. The hot and cold forging processes were set up based on the analyzed result. The mold and prototype were manufactured. Hardness, surface roughness, internal defect, the grain low line of the prototype were evaluated. The results showed no particular problems, and there were no problems in mass production. Using complex forging, the material was reduced by approximately 27 % compared to the process using hot forging and MCT machining. In addition, the production speed was improved 2.15 fold compared to that of hot forging and MCT machining. Through this study, a cost-effective process and mold design technology were established, which is expected to have positive effects on other related automotive parts production.

A study on rib-web shaped ring forging using UBET (UBET를 이용한 리브-웨브형 링 단조에 관한 연구)

  • Kim, Y.H.;Bae, W.B.;Nam, K.H.
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.5
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    • pp.134-142
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    • 1994
  • An upper bound elemental technique (UBET) is applied to predict variations of neutral plane and optimal position of the initial billet for rib-wep shaped ring forging. In the analysis, the neutral plane position and velocity fields are determined by minimizing the total power consump- tion with respect to chosen parameters. The degree of die-cavity filling by initial billet-position and the variations of neutral plane by friction condition are investigated. Experiments have been carried out with pure 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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Effect of Process Conditions on the Microstructure and Mechanical Properties of 7175Al Ring Roll Forgings (7175Al 링롤단조재의 미세조직과 기계적 성질에 미치는 공정조건의 영향)

  • Lee, I.G.;Kang, R.K.;Lee, O.Y.
    • Journal of the Korean Society for Heat Treatment
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    • v.17 no.1
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    • pp.10-16
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    • 2004
  • The aim of this study is to investigate the process conditions on the microstructual changes and mechanical properties of large 7175 aluminum ring roll forgings. The billets range from 370 mm to 720 mm in diameter were homogenized and ring roll forged after direct chill casting. The tensile properties of ring roll forged specimen manufactured with ${\Phi}370mm$ billets were superior to those of ${\Phi}720mm$ billets under $T_6$ condition. Also, these properties showed better than those of military specification under $T_{74}$ treatment. The impact value of ring roll forged specimen under $T_{74}$ treatment increased up to 20% than that of $T_6$ condition. The fracture toughness of ring roll forged specimen manufactured with ${\Phi}370mm$ cast billet showed nearly same level of ${\Phi}720mm$ billet which was processed using MF or Cog free forging followed by ring roll forging.

Plastic Forming of Rolling Bearing Steel Components (구름 베어링 부품의 소성가공)

  • 송복한;박창남
    • Transactions of Materials Processing
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    • v.12 no.2
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    • pp.83-87
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    • 2003
  • Current state of plastic processes of steel bearing parts is surveyed. According to the advances in plastic forming technologies and their great advantage to mass production, plastic processes are adopted in manufacturing majority of bering parts. The rings are forged or ring rolled and the rolling elements, i.e, balls or rollers are cold formed before fine machining. Bearing's steel retainers are mainly press formed using cold rolled seel strips. Including the general explanation about above processes, some details of forging technology, control of forging temperature and after cooling process, and examples of computer simulation are described.

Evaluation of Friction Shear Factor By the Lubricating Methods in Warm Forging (온간 단조에서 윤활 분사 방법에 따른 마찰 상수값의 평가)

  • 정덕진;김동진;김병민
    • Transactions of Materials Processing
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    • v.10 no.4
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    • pp.319-328
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    • 2001
  • Quantitative evaluation of the tribological conditions at the tool-workpiece interface in metal forming is usually accomplished by the ring compression test. This paper describes an experimental investigation into friction factor under warm forming conditions according to the lubricants and the lubricating methods using the ring compression test. Four different lubricants, two water based graphite and two oil based graphite lubricants, and three different lubricating methods were applied in the experiments. Calibration curves with the friction shear factor were obtained using FEM analysis and verified by the experimental results. The influence of lubricant and lubricating methods on friction are discussed. In the ring compression test, the lower friction factor got to spray the oil based lubricant on die and billet in warm forging temperature.

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