Internal void closure during the forging of large cast ingots using a simulation approach

Lee, Y.S.; Lee, S.U.; Tyne, C. J. Van; Joo, B.D.; Moon, Young Hoon

doi:10.1016/j.jmatprotec.2011.01.017

Cited by 106 publications

(65 citation statements)

References 23 publications

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“…The poor quality of manufactured large forgings is explained by the poor quality of ingots [6][7][8][9][10]. Design of new, more efficient, technological processes is possible through the use of finite element simulation [11][12][13][14][15][16][17][18].…”

Section: Literature Review the State Of The Artmentioning

confidence: 99%

“…One branch of the machine manufacturing industry that can use considerable improvement is the forging of large parts as shown in a paper by Ameli and Movahhedy (2007) [1]. A specific example is the manufacture of wide plates, which, despite the simplicity of the shape, represents a serious problem comprised of poor quality of obtained forged parts, major labor and energy expenditures resulting from an excessive number of operations, heats, and tool changeovers as have been shown in a paper by Lee et al (2011) [14]. The traditional process of forging wide plates consists of the following operations: lining of the faces on an ingot upsetting with formation of a dimple, forging by flat anvil blocks, forging by narrow blocks, chipping, and final straightening of a forged piece as described in a paper [9].…”

Section: Literature Review the State Of The Artmentioning

confidence: 99%

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Development of a new process for forging plates using intensive plastic deformation

Марков

Perig

Markova

et al. 2015

Int J Adv Manuf Technol

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A new method of plate forging with V-shaped dies is proposed. The deformation state of a metal workpiece during forging has been investigated. The proposed method of forging increases the uniformity of the strain distribution with a high level of strain in the workpiece. The values of angles for V-shaped dies range from 120°to 140°. This range of die angles is the most rational from the standpoint of strain distribution uniformity and maximum widening. V-shaped die usage for plate forging leads to an increase in widening coefficient of 35 % in comparison with forging with flat dies. This forging technique provides the possibility of eliminating the operation of billet upsetting during plate forging. V-shaped die usage for plate forging also results in a decrease in deformation load in comparison with flat die forging. The scheme of plate forging by V-shaped dies results in the formation of an irregular compression state in the axial zone. It leads to the closing of defects during forging. The new technology of plate forging with V-shaped dies was tested under industrial conditions. The forged piece has satisfied the requirements of the customer's technical criteria. The ultrasonic check results have shown that the application of the proposed technology provides an increase in metal continuity within the central zone of the forged piece. The experimentally derived forging results have confirmed that upsetting operations can be eliminated, and as a result, energy expenditures and the overall cycle time of the forging operation have been reduced by 15 %.

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Section: Literature Review the State Of The Artmentioning

confidence: 99%

Section: Literature Review the State Of The Artmentioning

confidence: 99%

Development of a new process for forging plates using intensive plastic deformation

Марков

Perig

Markova

et al. 2015

Int J Adv Manuf Technol

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“…It is believed that the stress state in the stagnant deformation zone at the end of forging is hydrostatic pressure, where the shear stress can exceed critical shearing strength of material, and laminated shear crack parallel to the section appears where the shear deformation is very significant, namely reaching the critical condition. However, most investigations on heavy forging defects in the upsetting process focus on both the surface crack [16][17][18] and closing/bonding of inner void [19][20][21][22][23][24] of the forgings in recently years. Based on the above, there is not a uniform interpretation to the inner laminated crack of large forgings and its criterion model yet.…”

Section: Introductionmentioning

confidence: 99%

“…In the past years, commercial FEA software MARC was used to simulate the closing process of the inner crack in cylindrical body during hot upsetting, analyse the stress and strain of the crack during deformation, and various factors that affect closing and bonding of the inner crack [25] . Banaszek [19,20] studied the upsetting process of a cylinder with a void by the commercial FEA software Forge and through simulation investigate the influence of forging processing on the internal void closure of the forgings and gain the reasonable forging conditions of defect-free. Based on DEFORM software, the coupling thermal-mechanical model of upsetting process was established separately by Zhang [17] and Huang [26] , and to investigate the effect of upsetting parameters on centre compaction and void changing.…”

Section: Introductionmentioning

confidence: 99%

Analysis of laminated crack defect in the upsetting process of heavy disk-shaped forgings

Wang

et al. 2016

Engineering Failure Analysis

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Using nonlinear finite element method, a thermo-mechanical coupled simulation model for the formation mechanism of the laminated crack defect has been established in the upsetting of heavy disk-shaped forgings. Through numerical simulation, the distributions of stress, equivalent strain and strain rate were analysed. Meanwhile the distribution diagram of stress state evolution was obtained, and the uncoordinated deformation, under tri-lateral compression, is determined as the main reason leading to laminated crack defect. To reveal the characteristics of the uncoordinated deformation, the variations of each variable and its gradient in numerical simulation were presented, and a combined prediction model of laminated crack defect were proposed based on degree of deformation and gradient of deformation speed. Subsequently, the morphology and distribution of laminated crack were obtained in the centre of forging using the prediction model. Comparison of calculation results and experimental data indicates that both of them match well. In addition, the effect of friction coefficient on the deformation is also presented. The results show that the decreasing of friction coefficient is an effective measure to restrain the laminated crack defect. Abstract: Using nonlinear finite element method, a coupling thermo-mechanical simulation model for the formation mechanism of the laminated crack defect has been established in the upsetting of heavy disk-shaped forgings. Through numerical simulation, the distributions of stress, equivalent strain and strain rate were analyzed. Meanwhile the distribution diagram of stress state evolution was obtained, and the uncoordinated deformation, under tri-lateral compression, is determined as the main reason leading to laminated crack defect. To reveal the characteristics of the uncoordinated deformation, the variations of each variable and its gradient in numerical simulation were presented, and a combined prediction model of laminated crack defect were proposed based on degree of deformation and gradient of deformation speed. Subsequently, the morphology and distribution of laminated crack were obtained in the centre of forging using the prediction model. Comparison of calculation results and experimental data indicates that both of them match well. In addition, the effect of friction coefficient on the deformation is also presented. The results show that the decreasing of friction coefficient is an effective measure to restrain the laminated crack defect.

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“…Numerical modelling of the forging process using the Finite Element (FE) method in a 2D [7] or 3D [8,9] environment has been a cornerstone for the optimisation of ingot forging in recent decades. Mostly based at a theoretical level, the relevance to industry was limited.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Void Closure during Open Die Forging Process of Large Size Steel Ingots

Harris

Shahriari

Jahazi

2016

KEM

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Abstract. Large size forged ingots, made of high strength steel, are widely used in aerospace, transport and energy applications. The presence of internal voids in the as-cast ingot may significantly affect the mechanical properties of final products. Thus, such internal defects must be eliminated during first steps of the open die forging process. In this paper, the effect of in-billet void positioning on void closure throughout the ingot breakdown process and specifically the upsetting step in a large ingot size steel is quantitatively investigated. The developed Hansel-Spittel material model for new high strength steel is used in this study. The ingot forging process (3D simulation) was simulated with Forge NxT 1.0 ® according to existing industrial data. A degree of closure of ten virtual existing voids was evaluated using a semi-analytical void closure model. It is found that the upsetting process is most effective for void closure in core regions and central upper billet including certain areas within the dead metal zone (DMZ). The volumetric strain rate is determined and two types of inertial effects are observed. The dependence of void closure on accumulated equivalent deformation is calculated and discussed in relation to void in-billet locations. The original combination of information from both relative void closure and the volumetric strain rate provides a way to optimize the forging process in terms of void elimination.

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Internal void closure during the forging of large cast ingots using a simulation approach

Cited by 106 publications

References 23 publications

Development of a new process for forging plates using intensive plastic deformation

Development of a new process for forging plates using intensive plastic deformation

Analysis of laminated crack defect in the upsetting process of heavy disk-shaped forgings

Analysis of Void Closure during Open Die Forging Process of Large Size Steel Ingots

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