A Review on Field Areas of Research in Forging Process using FEA

A Review on Field Areas of Research in Forging Process using FEA

Jasleen Kaur Research Scholar Mech. Engg. Deptt.

NITTTR

Chandigarh, India

B. S. Pabla

Professor Mech. Engg. Deptt.

NITTTR

Chandigarh, India

1. S. Dhami

   Professor Mech. Engg. Deptt.

   NITTTR

   Chandigarh, India

   Abstract-Forging is a core process of the manufacturing industry. Being a primary metal forming process, it defines the mechanical properties of the part in the initial stage of manufacturing. An aligned grain flow pattern and a sound metal flow define a good forging. The present paper discusses the various fields of forging research. The different fields are basically the perspectives to produce a good quality product. Finally, the unexplored areas of research where further investigation is required are also given.

   Keywords- Forging, Finite Element Analysis, Numerical Simulation, Forging Defects, Optimization

   1. INTRODUCTION

      Forging is a primary metal forming process. It has an advantage over other processes because it gives products which have superior mechanical properties and is manufactured with minimum wastage of material. Forged parts have good strength and toughness which makes them suitable for use in highly stressed and critical applications like bevel gear, crankshaft, axle, connecting rod, etc. Various parameters that affect the forging operation are the material characteristics like material strength, ductility, deformation rate, temperature sensitivity and frictional characteristics of the workpiece, preform design, die design and die material. Process parameters include the type of forging press/hammer used, friction between die and workpiece, forging load, speed of operation of press, number of strokes required, temperature of workpiece and dies, etc. [67, 68]

   2. LITERATURE REVIEW

      The literature for forging is divided into various categories depending on the research done like defect removal, optimization of process, design of preform for forging, etc. The techniques used in the papers, the modifications done, results observed and case studies have also been discussed.

      1. Defect Removal

         Defect removal is a critical area of forging research because of the high losses resulting from rejections or rework in forging industry. The various geometrical defects that occur are lapping, mismatch, scales, quench cracks, underfilling, etc. [Thottungal and Sijo, 2013]. These can result from a poor design or poor execution of manufacturing or due to material related problems. These defects were investigated and rectified by various researchers using case studies of integral axle arm [Mathew, Koshy and Varma, 2013], axially symmetrical and flanged components [Chan, Fu and Lu, 2010], synchronizer ring [Chen, Zeng and Zheng, 2010], stud bolt [Doddamani and Uday, 2012], steel end plate used in automobile axles [Gulati et al., 2012], etc. The table1 describes the techniques used, modifications done, software used and the observed results in detail.

         TABLE I DEFECT REMOVAL

         Reference	Aim of Research Work	Technique used	Modification done	Software used	Component	Results observed
         [Thottungal and Sijo, 2013]	Controlling Measures to Reduce Rejection Rate due to Forging Defects	FEA	Material flow, proper lubricant, anti-scale coating, venting process to prevent underfilling	–	General	Better quality of forgings
         [Mathew, Koshy and Varma, 2013]	Study of Forging Defects in Integral Axle Arms	Pareto chart, Cause and effect diagram	Process and design parameters	–	Integral Axle Arms	Proper scale removal resulted in complete filling of die, lap formation was reduced
         [Chan, Fu and Lu, 2010]	FE Simulation-Based Folding Defect Prediction and Avoidance in Forging of Axially Symmetrical Flanged Components	FEA	Variation of geometry parameters and identification of the sensitivity of each parameter to folding defect	–	Automotive part	Material flow was improved and folding was removed
         [Chen, Zeng and Zheng, 2010]	Numerical analysis and defects of forging technology for synchronizing steel ring of automobile	FEA	Change in workpiece diameter, die structure and friction factor	DEFORM 3D	Synchronizing ring	Defect free forging, relation between maximum load and friction factor, effective strain distributions, effective strain rate distributions, effective stress distributions, velocity distributions and the load-stroke curves
         [Doddamani and Uday, 2012]	Simulation of Closed die forging for Stud Bolt and Castle Nut using AFDEX for prediction of defects	FEA	Process and design parameters	AFDEX	Stud bolts and castle nut	Effective stress, complete filling of die, load stroke curve
         [Gulati et al., 2012]	Simulation and optimization of material flow forging defects in automobile component and remedial measures using deform software	FEA	Change in positioning of billet	DEFORM 3D	Steel end plate used in automobile axles	Defect free part, temperature distribution, scrap volume

      2. Ease of Manufacturing

         Viability of manufacturing components is another aspect that is of importance to the industrialists which aids in the manufacturing of part with minimum forging load [Lei and Lissenden, 2001]. It can be executed through a proper die design, optimum billet shape and size and optimum process

         conditions [Mangshetty and Balgar, 2012]. These have been explained through various case studies have been taken up by researchers which include parts like wear specimen and centre guide [Lei and Lissenden, 2001], helical forging [Yang, Chang and Wang, 2010], aluminium alloy wheel [Zhu et al., 2010], etc. The details are given in the table II.

         TABLE II EASE OF MANUFACTURING

         Reference	Aim of Research Work	Technique used	Modification done	Software used	Component	Results observed
         [Lei and Lissenden, 2001]	FE simulation of ausforming of austempered ductile iron components to investigate the viability of manufacturing of the component	FEA	Change in design of perform and die set geometry	DEFORM 3D and ABAQUS	Wear specimen and centre guide	Optimum forging load, equivalent plastic strain distribution and the final geometry
         [Yang, Chang and Wang, 2010]	Predictions of Maximum Forging load and Effective Stress for Strain- Hardening Material of Near Net- Shape Helical Gear	FEA, Abductive network	Variation of material parameters like yielding stress, strength coefficient and strain hardening exponent	DEFORM 3D	Helical Gear	Optimum forging load, effective stress
         [Zhu et al., 2010]	Forging Simulation of Aluminum Alloy Wheels	FEA	Process parameters like billet temperature, punch speed, lubrication	SUPERFORM/ SUPERFORGE	Aluminium alloy wheel	Reduction in the number of steps of forging required, Reduction of billet weight, elimination of folding defect, complete filling of wheel rim
         [Nefissi, Bouaziz and Zghal, 2008]	Prediction and simulation of axisymmetric forging load of aluminium	FEA	Process and design parameters	DEFORM	Basic upsetting	Load stroke curve, load prediction
         [Mangshetty and Balgar, 2012]	Billet shape optimization for minimum forging load using FEM analysis	FEA	Use of Fem and ADPL algorithm and modification of billet shape	ANSYS	General	Crack free forgings, minimum forging load, von mises stress, displacement plot, radial and hoop stress plot, contact pressure plot, strain values

      3. Process Optimization

         The forging process can be optimized by variation of various process parameters like punch velocity, friction coefficient, temperature, etc. [Feng and Hua, 2010]. An optimized process is a good approach because it gives a good quality forging with minimum forging load. Various

         components have been studied like automotive starter motor ring gear [Wang et al., 2010], compressor blade [Zhang et al., 2010], helical gears [Feng and Hua, 2010], pneumatic clamp [Milutinovi et al., 2011], spindle and gear [Bonte et al., 2010], reservoir forging [Chiesa et al., 2004], screw head and clinched joint [Chenot et al., 2011], etc. The following table III gives the details.

         TABLE III PROCESS OPTIMIZATION

         Reference	Aim of Research Work	Technique used	Modification done	Software used	Component	Results observed
         [Wang et al., 2010]	Numerical simulation and Analysis of Forging Process for Automotive Starter Motor Ring Gear	FEA	Optimization of process parameters	–	External boss and internal gear for automobile	Proper metal flow, stress distribution and strain distribution
         [Zhang et al., 2010],	Process Optimization for Isothermal Forging of TiAl Compressor Blade by Numerical Simulation	FEA	Modification of perform dimensions	DEFORM 3D	Compressor blade	Optimized process, effect of friction coefficient on forging load, thickness of flash and microstructure
         [Feng and Hua, 2010]	Process parameters optimization for helical gears precision forging with damage minimization using FE simulation	FEA	Modification of process parameters like punch velocity, friction coefficient, temperature	DEFORM 3D	Helical Gear	Optimized process, maximum damage factor vs punch velocity, friction coefficient, temperature and distribution of damage factor
         [Schaeffer, Brito and Geier, 2005]	Numerical simulation using finite elements to develop and optimize forging processes	FEA	Process and design parameters	Q Form 3D	Billet	Optimized process, flow curves at different temperatures and strain rates
         [Milutinovi et al., 2011]	Design of hot forging process of parts with complex geometry in digital environment	FEA	Process and design parameters	Simufact	Pneumatic clamp	Reduced flash, complete filling of die, effective stresses, reduced material required for preform
         [Bonte et al., 2010]	Optimization of forging processes using Finite Element simulations	FEA	Use of metamodel algorithms to optimize forging	–	Spindle, gear	Decreased energy consumption and folding susceptibility of gear, sound results
         [Chiesa et al., 2004]	Parallel Optimization of Forging Processes for Optimal Material Properties	FEA	Process and design parameters	PRONTO2D	Typical reservoir forging	Yeild strength contour, stress states
         [Chenot et al., 2011]	Numerical Simulation and Optimization of the Forging Process	FEA	Process and design parameters	Forge 3	Screw head, clinched joint	Von mises stress distribution, tension test, surface response

      4. Preform Design

         Preform design includes the changing the billet shape, flash thickness and width, corner and fillet radii for reduced forging loads and complete die filling [Equbal et al., 2012]. A good preform design aids in the proper distribution of metal in the die cavity. The case studies taken up by

         researchers include rail rection and 3D metal hub [Thiyagarajan and Grandhi, 2005], pinion and helical gearing [Kang, Kim and Kang, 2007], connecting rod [Equbal et al., 2012], gear [Haider, Pathak and Agnihotri, 2010], etc. The tableIV defines clearly that FEA has been widely used for analysis.

         TABLE IV PREFORM DESIGN

         Reference	Aim of Research Work	Technique used	Modification done	Software used	Component	Results observed
         [Thiyagarajan and Grandhi, 2005]	3D preform shape optimization in forging using reduced basis techniques	FEA, reduced basis techniques	Change of billet shapes	DEFORM	Rail section and 3D metal hub	Strain variance, flash volume, underfill volume, load
         [Kang, Kim and Kang, 2007]	Numerical analysis and design of pinion with inner helical gear by FEM	FEA	Design of preform	DEFORM 3D	Pinion and helical gearing	Effective strain, load stroke curve, harness distribution
         [Equbal et al., 2012]	Preform Shape Optimization of Connecting Rod using Finite Element Method and Taguchi Method	FEA, Taguchi method	Modification of billet shape, flash thickness and width, corner and fillet radius	DEFORM 3D	Connecting Rod	Forging load, defect free forging, complete die filling, metal flow
         [Haider, Pathak and Agnihotri, 2010]	Preform design for near net shape close die gear forging using simulation technique	FEA	Modification of preform	Simufact	Gear	Effective stress, load stroke curve, maximum effective plastic strain

      5. Damage Models

         Damage models define the behavior of the system during forging. Various failure criteria are available, the suitability of which can be figured out using experimentation which

         can define the workability limits of forging [Rao, Kumar and Ramakrishnan, 2007]. The damage models can be compared using FEA technique to find out which one depicts the damage effectively [Christiansen et al., 2013]. The details are given in tableV.

         TABLE V DAMAGE MODELS

         Reference	Aim of Research Work	Tecnique used	Modification done	Software used	Component	Results observed
         [Rao, Kumar and Ramakrishnan, 2007]	Investigation of the effectiveness of theoretical failure criteria in the estimation of Workability Limits in Cold Forging through FEA	FEA	Variation of failure criteria	ABAQUS	Upsetting	Maximum principle stress, hydrostatic stress, effective strain, Gursons RD, hoop stress, axial stress
         [Christiansen et al., 2013]	Modelling of Damage During Hot Forging of Ingots	FEA	Use of different ductile damage criterion	–	Upsetting of flanged part	Damage criterion, stress triaxiality, equivalent plastic strain, element strain loading paths
         Meidert, Walter and Pohlandt]	Prediction of fatigue life of cold forging tools by FE simulation and comparison of applicability of different damage models	FEA	Application of various damage models	DEFORM and ANSYS	Cold forging tools	Damage after deformation of workpiece

      6. Die Analysis

         Die life is an important parameter in forging industry because of the high cost of die involved. Fatigue analysis of dies using FEA can give a good estimation of life of forging die and punch [Horita et al., 2012]. The surface texture of die is also an

         essential criteria because it affects the coefficient of friction and hence the metal flow in forging [Menezes, Kishore and Kailas, 2010]. The wear of die can be reduced by changing the rotational speed of the upper die, feed rate of the lower die, diameter workpiece [Han and Hua, 2013]. The details are given in the tableVI.

         TABLE VI DIE ANALYSIS

         Reference	Aim of Research Work	Technique used	Modification done	Software used	Component	Results observed
         [Horita et al., 2012]	Fatigue Analysis of Forging Die	FEA	Forgings tests, bending fatigue tests	SIMUFACT, CYBERNET, ANSYS	Forged part	Load vs stroke, fatigue analysis of forging die, stress distribution, stress intensity factor
         [Menezes, Kishore and Kailas, 2010]	A Study on the Influence of Die Surface Textures during Metal Forming Using Experiments and Simulation	FEA	Compression tests and variation of friction coefficients	DEFORM 3D	Cylinder	Variation of coefficient of friction with sliding distance, surface roughness, surface texture, load stroke curve, effective stress, maximum principle stress, strain rate
         [Han and Hua, 2013]	3D FE Modeling Simulation for Wear in Cold Rotary Forging of 20CrMnTi Alloy	FEA	Modification of rotational speed of upper die, feed rate of lower die, outer/inner diameter of the ring workpiece	ABAQUS	Cold rotary forging of ring	Contact pressure, slip distance response, wear response, friction calibration curves, energy curves of deforming workpiece

      7. Comparison of Constitutive laws

      Constitutive equations define the flow stress of material. Forging force, stress and strain can be studied to compare the constitutive laws to find out which one gives better results [Pantalé and Gueye, 2013]. The details are given in the tableVII.

      TABLE VII COMPARISON OF CONSTITUTIVE LAWS

      Reference	Aim of Research Work	Technique used	Modification done	Software used	Component	Results observed
      [Pantalé and Gueye, 2013]	Influence of the Constitutive Flow Law in FEM Simulation of the Radial Forging Process	FEA	Comparison of different constitutive flow laws	–	2D axisymmetric component	Forging force, product thickness, strains, stresses and CPU time

      Various researchers have done similar research works the details of which are given in table VIII.

      TABLE VIII USE OF FEA

      Reference	Aim of Research Work	Technique used	Modification done	Software used	Component	Results observed
      [Chenot, Bouchard, Fourment and Lasne, 2011]	Numerical Simulation and Optimization of the Forging Process	FEA	Process and design parameters	Forge 3	Screw head, clinched joint	Von mises stress distribution, tension test, surface response
      			Modification of
      			geometric
      			parameters,
      			solidification
      [Zhbankov and Perig, 2013]	Study of Forging of Ingots Without Hot Tops and shrinkage cavities	FEA	conditions and steel chemical composition and the use of	–	Ingot	Equivalent plastic strain, deformation of upset
      			preliminary
      			upsetting by plates
      			with holes instead
      			of hot tops
      	Eliminating Forging
      [António, Castro and Sousa, 2005]	Defects the use of Genetic Algorithms to calculate optimal shape geometry and	Genetic Algorithms	Modification of preform design and workpiece temperature	–	Axisymmetric H shaped component	Highest temperature detected during forging
      	temperature
      	A methodology for
      [Fu et al., 2006]	evaluation of metal forming system design and performance via	FEA	Development of quantitative design evaluation criteria	–	Forged part	Deformation load, damage factor, stress distribution
      	CAE simulation
      [Qingping, Huanyong and Yuzeng, 2010]	Process Design for Cold Precision Forging of Bevel Gear using finite element method	FEA	Change in forming laws, material plastic behavior and changed geometries	–	Bevel gear	Effective strain, effective stress, load stroke curve
      [Hu et al., 2010]	Study on precision forging process of spur gear in parking brake using fem	FEA	Change in process parameters like forging temperature and different contact conditions	DEFORM 3D	Spur gear in parking brake	Temperature fields, velocity distribution, equivalent strain fields, load stroke curve

      	Research on Finite
      	Element Modeling
      [Wang et al., 2010]	Technique of recision Forming Simulation for	FEA	Process and design parameters	DEFORM 3D	Hookes Joint	Equivalent strain, stress and velocity fields,
      	Complex Precision
      	Forging Part
      	Numerical
      	Simulation and
      [Liang and Pin, 2010]	Technology Research on the Precision Forging for Speed-Reducer	FEA	Process and design parameters	–	Speed-Reducer Shaft of Auto Starter	Equivalent stress, equivalent velocity field, punch force vs displacement
      	Shaft of Auto
      	Starter
      	Numerical
      	simulation and				Forging of
      [Wang et al., 2010]	Analysis of Forging Process for	FEA	Process and design parameters	DEFORM 3D	external boss and internal gear	Metal flow, stress strain distributions
      	Automotive Starter				for automotive
      	Motor Ring Gear
      						Die and slug
      [Gronostajski and Hawryluk, 2008]	The main aspects of precision forging	FEA	Tool and preform temperature, slug geometry, press settings, process speed, lubrication and cooling, tool shape	MSC. Marc	Arch and conical dies for forging CV joint tulips	thermal field distribution, material flow, plastic strain, vector distribution of unit pressures, hoop stress distribution, von mises stress
      						distribution
      	Relations between					Strain field
      [Skunca et al., 2006]	numerical simulation and experiment in closed die forging of	FEA	Process and design parameters	MSC. Marc Mentat	Tooling design for radial gear extrusion	distribution, grain size vs strain, force stroke curve, total equivalent plastic
      	a gear					strain
      			Change in forging
      [Chyla et al., 2011]	Closed die forging of turbine disc to fix blades from inconel	FEA	temperatures, tools temperature, friction, deformation size in	–	Turbine disc	Mean stress distribution, maximum load
      			upsetting operation
      [Jolgaf et al., 2008]	Closed Die Forging Geometrical Parameters Optimization for Al- MMC	FEA	Billet, radius, the rib height/width ratio, fillet radii, draft angle	ANSYS	Circular H shaped part	Equivalent strain distribution, contact gap
      	Forming of external
      [Gontarz and R.Myszak, 2010]	steps of shafts in three slide forging		Process and design parameters	–	Stepped shaft	Nomogram
      	press
      	Application of the					Stress strain
      [Maria, Roque and Button, 2000]	Finite Element Method In Cold	FEA	Upsetting and ring compression test	ANSYS	Basic	material curve, material flow,
      	Forging Processes					forming force
      	Numerical analysis
      [Lacki, 2009]	of the void evolution during metal plastic	FEA	Process and design parameters	ADINA system	Rolling bearing	Plastic strain distribution, better quality of products
      	deformation

      [Rith et al., 2009]	Experimentally validated approach for the simulation of the forging process using mechanical vibration	FEA	Process and design parameters	FORGE 2008	Basic upsetting	Force vs displacement curve, forging load vs displacement curve, forging load reduction vs normalised speed
      	Evaluating
      [Wang et al., 2010]	interactions between the heavy forging process and the assisting manipulator combining FEM simulation and	FEA	Process and design parameters	DEFORM 3D	Rounding of quadrangle cast blank, drawing of a rotor from an octagonal cast blank	Displacement and velocity variation with time, variation of load, temperature distribution, variation of reaction load
      	kinematics analysis
      	Processing
      [Sun, Tzou and Zheng, 2013]	animation simulation and FEM analysis of multi- stage cold forging of stainless automotive	FEA	Process and design parameters	DEFORM 3D	Automotive battery fastener	Effective stress, effective strain, velocity field, forging force
      	battery fastener
      	Numerical
      	Simulation and
      [Liang and Pin, 2010]	Technology Research on the Precision Forging for Speed-Reducer	FEA	Process and design parameters	–	Speed-Reducer Shaft of Auto Starter	Equivalent stress, equivalent velocity field, punch force vs displacement
      	Shaft of Auto
      	Starter
      	Process Design of
      	Extend Forging
      [Kakimoto et al., 2009]	Process Using Numerical Simulation Development of Process Design Method for the	FEA	Variation of feed, rotation angle, octagon size	FORGE 3D	Octagon process	Radius distribution, relation between angle of rotation and dimensional deviation
      	Finish Forging
      	Process
      						Effective stress,
      						effective plastic
      						strain, force stroke
      						curve, contact
      	Simulation of finite		Variation in			pressure,
      [Maarefdoust, 2012]	volume of hot forging process of	FEA	cefficient of friction,	SuperForge	Gear	temperature distribution,
      	industrial gear		temperature			maximum stress vs
      						coefficient of
      						friction, effect of
      						temperature on
      						force
      [Slagter, 2001]	Forging Simulation Tool Based on Breakthrough Technology	FEA	Process and design parameters	MSC.Superforge	pulley, crankshaft	Tooling cost savings, production line downtime savings, material cost savings
      [Sambhunath and M.T.Sijo, 2013]	Process parameters designing and simulation for the non isothermal forging of Ti-6Al- 4V alloy	FEA	Process and design parameters and flow stress models	ANSYS	Cylinderical billet	Flow stress vs temperature, flow stress vs strain rate, stress sensitivity vs temperature, deformation plot, stress distribution,

      						Stress, strain,
      						temperature, force,
      [Gohil, 2012]	The Simulation and Analysis of the Closed Die Hot Forging Process	FEA	Process and design parameters	–	General upsetting	flow stress and maximum stress vs deformation, strain vs deformation, load stroke curve,
      						temperature vs
      						deformation
      						Effective strain
      [Chen, Ku and Chen, 2012]	Study of Forging Process in 7075 Aluminum Alloy Professional Bicycle Pedal using Taguchi Method	FEA	Workpiece temperature, mold temperature, forging speed, friction factor	DEFORM 3D	Professional bicycle pedal	distribution, effective stress distribution, load variation, damage distribution, maximum principle
      						strain distribution
      						Effective plastic
      						strain vs
      [Maarefdoust and M.Kadkhodayan, 2010]	Simulation and analysis of hot forging process for industrial locking gear elevators	FEA	Billet temperature, preform, geometry of die,	Superforge	Industrial locking gear elevator	temperature, effective plastic strain distribution, effective stress vs die corner radius, flash thickness vs
      						press force, force
      						cycle curve
      [Arbak et al., 2007]	Forging Simulation at Izeltas	FEA	Modification of temperature, lubrication conditions	Quantors Qform, MSCs Superforge, SFTCs DEFORM, Transvalors Forge 3	Steering mechanism joint, ring wrench	Stress and temperature distributions, strain rate
      	Pseudo Inverse its	Pseudo Inverse				Equivalent plastic
      [Meng et al., 2011]	comparison with Adaptive Incremental	Approach, Adaptive Incremental	Process and design parameters	ABAQUS	Wheel	strain and stress, comparison of computation time of
      	Approach	Approach				softwares
      						No mesh distorsion
      [Joseph, Cleary and Prakash, 2006]	SPH modelling of metal forging	FEA, Smooth particle hydrodynamics	Change in hardness parameter, size of workpiece	–	General	or remeshing, removal of defects, plastic strain
      						distribution
      [Moradi and Nayebsadeghi, 2011]	3D simulation of the forging process of a gas turbine blade of nickel-based superalloy	FEA	Process and design parameters	–	Gas turbine blade	Temperature distribution, equivalent strain distribution, load displacement curve, flow stress
      [Gontarz, Z.Pater and K.Drozdowski,2013]	Hammer forging process of lever drop forging from az31 magnesium alloy	FEA	Process and design parameters	DEFORM 3D	Lever	Material flow kinematics, strain and damage criterion distributions, forging energy
      	Finite element
      	modelling and					Maximum
      [Sharma and K.Hans Raj, 2008]	simulation of hot upsetting process to minimize central	FEA	Preform and process design	–	Basic upsetting	equivalent strain rate, forging load, radius of curvature,
      	bulge in					bulge error
      	manufacturing

      						Load curves, metal
      	Comparison					flow analysis,
      [Han and Lin Hua, 2009]	between cold rotary forging and conventional	FEA	Process and design parameters	ABAQUS	Cylindrical workpiece	plastic deformation zone distribution, axial and radial
      	forging					strain distribution,
      						force and power
      	The Knowledge
      	Based System for
      [Numthong and S.Butdee, 2012]	Forging Process Design based on Case-Based Reasoning and	FEA, Case- Based Reasoning	Process and design parameters	DEFORM 3D, Manusoft	Rear axial shaft	Effective stress and strain distributions, temperature distribution
      	Finite Element
      	Method
      [Skubisz, Sinczak and Chyla, 2008]	Reduction of die loading by divided flow pattern in the finisher die web area	FEA	Process and design parameters	Qform 3D	Flanged component	Metal flow velocity, tool stress analysis, effective stress, contact surface
      						Velocity
      						distribution plots,
      	Simulation of					damage factor, load
      [Hussain et al., 2002]	clutch-hub forging process using	FEA	Process and design parameters	CAMPform	Clutch-hub	requirements, complete filling of
      	p>CAMPform					die, material flow,
      						effective strain
      						distribution,
      	Benchmark of a
      	forging process with
      	a hammer:					Equivalent von
      [Laberg`ere, 2011]	comparison between fem simulation	FEA	Process and design parameters	ABAQUS	Cylindrical part	mises stress vs equivalent plastic
      	results and real part					strain, damage,
      	shapes using 3D
      	digitising scanner

   3. DISCUSSIONS

      The various fields of research are the different perspectives to manufacture a good quality part. The field of optimization of process includes almost every aspect of research. It includes the optimum die design, preform design and the process parameters, which result in manufacturing of a defect free part with minimum forging load. An overview of the techniques of research shows that almost every researcher has used FEA for the analysis of forging operation. It is because of the advantages over other methods of analysis like slab method, slip line field method, upper bound method; which do not consider the temperature gradients which are present in the deforming material during hot forming operation. The use of FEA can also be attributed to the fact that it provides detailed information using soft computing and save a lot of time, effort and the resources of production. It allows the simulation of various things like the tool and workpiece temperatures, the heat transfer during deformation, strain- rate-dependent material properties, strain hardening characteristics and capabilities for microstructure analysis.

   4. CONCLUSIONS

Most of the research work has been done in the field of defect removal of forgings mainly through the use of finite element analysis. The technique is quite useful for prediction of defects, optimization of process, die analysis, forging loads, etc. The results of FEA have been validated by every researcher. Apart from using FEA various other techniques have been used by researchers like variational approach, genetic algorithms, reduced basis technique, adaptive remeshing technique, slab method analysis, case based reasoning, etc. The results are reduced cycle time, reduction of shop floor trials, removal of defects, production of optimized forgings, better die life, etc. A very few researchers have worked upon the control of the virtual environment of forging like damage models. This is a good field of research which can be explored. The study of constitutive equations in numerical modeling, different friction models, different material behavior and different solving methods can be further explored so that the virtual environment for simulation can be given a stronger foundation, thus, improving the forging operation. Metal flow is an area where minimal work has been done. It has not been related to any of the other parameters like stress and strain in the component or the design of the die. A

mathematical model related to metal flow can be very useful while die designing of the forging dies. FEA is a very strong base for research in the field of forging because it gives minimal effort for a flawed die design or an imperfect process plan.

REFERENCES

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3. Olivier Pantalé and Babacar Gueye, Influence of the Constitutive Flow Law in FEM Simulation of the Radial Forging Process, Journal of Engineering, pp.1-8 (2013).

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10. Sunil Mangshetty and Santosh Balgar, Billet Shape Optimization for Minimum Forging Load using FEM Analysis, International Journal of Engineering Research and Development, Vol. 3, Issue 3, ISSN 2278-800X, pp.11-16 (2012).

11. M.R.Doddamani and M.Uday, Simulation of Closed die forging for Stud Bolt and Castle Nut using AFDEX, International Journal of Engineering and Innovative Technology, Vol. 1, Issue 3, ISSN 2277- 3754, pp.16-22 (2012).

12. A.Horita, S.Ishihara, T.Goshima, M.Kawamoto, E.Kurosaki, M.Sawai and M.Takata, Fatigue Analysis of Forging Die, Journal of Thermal Stresses, ISSN 0149-5739, pp.157-168 (2012).

13. C.Numthong and S.Butdee, The Knowledge Based System for Forging Process Design based on Case-Based Reasoning and Finite Element Method, Asian International Journal of Science and Technology in Production and Manufacturing Engineering, Vol. 5, No. 2, pp. 45-54 (2012).

14. Piyush Gulati, Rajesh Kanda, Jaiinder Preet Singh and Manjinder Bajwa, Simulation and Optimization of Material Flow Forging Defects in Automobile Component and Remedial Measures using Deform Software, International Journal of Mechanical Engineering and Technology, Vol. 3, Issue 1, ISSN 0976-6340, pp.204-216 (2012).

15. Mahdi Maarefdoust, Simulation of Finite Volume of Hot Forging Process of Industrial Gear, International Conference on Networks and Information, Vol. 57, pp.111-115 (2012).

16. Dyi-Cheng Chen, Wen-Hsuan Ku and Ming-Ren Chen, Study of Forging Process in 7075 Aluminum Alloy Professional Bicycle Pedal using Taguchi Method, World Academy of Science, Engineering and Technology, pp.903-906 (2012).

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19. Mladomir Milutinovi, Dejan Movrin, Miroslav Planak, Saa Ranelovi, Toma Pepelnjak and Branimir Barii, Design of Hot Forging Process of Parts with Complex Geometry in Digital Environment, Trends in the Development of Machinery and Associated Technology, Prague, Czech Republic, pp.101-104 (2011).

20. F.J.Meng, A.Halouani, C.Labergere, Y.M.Li, B.Abbes, P.Lafon and Y.Q.Guo, Pseudo Inverse Approach for Cold Forging Processes and its Comparison with Adaptive Incremental Approach, 20ème Congrès Français De Mécanique Besançon, pp.1-6 (2011).

21. Mehran Moradi and Mohammadreza Nayebsadeghi, 3D Simulation of the Forging Process of a Gas Turbine Blade of Nickel-based Superalloy, Canadian Journal on Mechanical Sciences and Engineering, Vol. 2, No. 2, pp.19-22 (2011).

22. Jean-Loup Chenot, Pierre-Olivier Bouchard, Lionel Fourment and Patrice Lasne, Numerical Simulation and Optimization of the Forging Process, International Cold Forging Congress, Stuttgart, Germany (2011).

23. Carl Laberg`ere, S´ebastien Remy, Pascal Lafon, Arnaud Delespierre, Laurent Daniel and Gao Kang, Benchmark of a Forging Process with a Hammer: Comparison between FEM Simulation Results and Real Part Shapes using 3D Digitising Scanner, M´ecanique and Industries, pp.215-222 (2011).

24. Piotr Chyla, Aneta Lucaszek, Sylwia Bednarek and Pawel Chyla, Closed Die Forging of Turbine Disk to Fix Blades from Inconel 718, Metallurgy and Foundry Engineering, Vol. 37, No. 2, pp.151- 158 (2011).

25. Tung-Sheng Yang, Sheng-Yi Chang and Jian-Hui Wang, Predictions of Maximum Forging load and Effective Stress for Strain-Hardening Material of Near Net-Shape Helical Gear Forging, 2nd International Conference on Computer Engineering and Technology, Vol. 6, pp. 628-633 (2010).

26. Pradeep L.Menezes, Kishore and Satish V.Kailas, Influence of Die Surface Textures during Metal FormingA Study Using Experiments and Simulation, Materials and Manufacturing Processes, ISSN 1042-6914, pp.1030-1039 (2010).

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28. Zhang Qingping, Cui Huanyong and Wang Yuzeng, Process Design for Cold Precision Forging of Bevel Gear, International Conference on Digital Manufacturing and Automation, pp.114-116 (2010).

29. Cheng-Liang Hu, Li Wang, Zhen Zhao, Hai-Ying Zhang and Yi-Hua Wang, Study on Precision Forging Process of Spur Gear in Parking Brake, International Conference on Advanced Technology of Design and Manufacture, pp.268-273 (2010).

30. Jie Chen, Shun-Peng Zeng and Ji-Chao Zheng, Numerical Analysis and Defects of Forging Technology for Synchronizing Steel Ring of Automobile, IEEE, pp.478-481 (2010).

31. Ping Wang, Liang Li, Bin Wang and Yi Lian, Numerical Simulation and Analysis of Forging Process for Automotive Starter Motor Ring Gear, International Conference on System Science, Engineering Design and Manufacturing Informatization, pp.296-298 (2010).

32. H.Zhang, Y.Y.Zong, W.C.Xu and D.B.Shan, Process Optimization for Isothermal Forging of TiAl Compressor Blade by Numerical Simulation, IEEE, Vol. 5, pp.412-415 (2010).

33. Wei Feng and Lin Hua, Process Parameters Optimisation for Helical Gears Precision Forging with Damage Minimization, International Conference on Digital Manufacturing and Automation, pp.117-120 (2010).

34. Ping Wang, Bin Wang, Liang Li and Aihua Chen, Research on Finite Element Modeling Technique of Precision Forming Simulation for Complex Precision Forging Part, International Conference on Networking and Digital Society, pp.532-535 (2010).

35. Zhihua Zhu, Huixue Sun, Jinhua Hu, Yixiang Wang and Zhiquan Xiao, Forging Simulation of Aluminum Alloy Wheels, IEEE (2010).

36. A.Gontarz and R.Myszak, Forming of External Steps of Shafts in Three Slide Forging Press, Archives of Metallurgy and Materials, Vol. 55, Issue 3, pp.689-694 (2010).

37. Ping Wang, Liang Li, Bin Wang and Yi Lian, Numerical Simulation and Analysis of Forging Process for Automotive Starter Motor Ring Gear, International Conference on System Science, Engineering Design and Manufacturing Informatization, pp.296-298 (2010).

38. Li Liang and Wang Pin, Numerical Simulation and Technology Research on the Precision Forging for Speed-Reducer Shaft of Auto Starter, International Conference on System Science, Engineering Design and Manufacturing Informatization, pp.314-317 (2010).

39. Wu-rong Wang, Kai Zhao, Zhong-qin Lin and Hao Wang, Evaluating Interactions Between the Heavy Forging Process and the Assisting Manipulator Combining FEM Simulation and Kinematics Analysis, International Journal of Advanced Manufacturing Technology, pp.481-491 (2010).

40. Mohammad Haider, K.K.Pathak and Geeta Agnihotri, Preform Design for Near Net Shape Close Die Gear Forging using Simulation Technique, Archives of Applied Science Research, Vol. 2, ISSN 0975-508X, pp.317-324 (2010).

41. Martijn H.A.Bonte, Lionel Fourment, Tien-tho Do, A. H. van den Boogaard and J. Hu̩tink, Optimization of Forging Processes using Finite Element Simulations РA Comparison of Sequential Approximate Optimization and other Algorithms, Structural and Multidisciplinary Optimization, pp.797-810 (2010).

42. M.Maarefdoust and M.Kadkhodayan, Simulation and Analysis of Hot Forging Process for Industrial Locking Gear Elevators, NUMIFORM 2010, Proceedings of the 10th International Conference, pp.903-909 (2010).

43. P.Lacki, Numerical Analysis of the Void Evolution during Metal Plastic Deformation, Archives of Metallurgy And Materials, Vol. 54, Issue 3, pp.567-574 (2009).

44. Ly Rith, Giraud-Audine Christophe, Abba Gabriel and Bigot Régis, Experimentally Valided Approach for the Simulation of the Forging Process using Mechanical Vibration, International Journal of Material Forming, pp.133-136 (2009).

45. Xinghui Han and Lin Hua, Comparison between Cold Rotary Forging and Conventional Forging, Journal of Mechanical Science and Technology, Vol. 23, pp.2668-2678 (2009).

46. Hideki Kakimoto, Yoichi Takashi, Hideki Takamori, Tatsuya Tanaka and Yutaka Imaida, Process Design of Extend Forging Process using Numerical Simulation Development of Process Design Method for the Finish Forging Process, Materials Transactions, Vol. 50, No. 8, pp.1998-2004 (2009).

47. M.Jolgaf, S.B.Sulaiman, M.K.A.Ariffin and A.A.Faieza, Closed Die Forging Geometrical Parameters Optimization for Al-MMC, American Journal of Engineering and Applied Sciences, ISSN 1941- 7020, pp.1-6 (2008).

48. Rahul Swarup Sharma and K.Hans Raj, Finite Element Modelling and Simulation of Hot Upsetting Process to Minimize Central Bulge in Manufacturing, XXXII National Systems Conference, pp.485-489 (2008).

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50. Z.Gronostajski and M.Hawryluk, The Main Aspects of Precision Forging, Archives of Civil and Mechanical Engineering, Vol. 3, pp.39-55 (2008).

51. Piotr Skubisz, Jan Sinczak and Pawel Chyla, Reduction of Die Loading by Divided Flow Pattern in the Finisher Die Web Area, Metallurgy and Foundry Engineering, Vol. 34, No. 1, pp.23-32 (2008).

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54. A.Venugopal Rao, R.Krishna Kumar and N.Ramakrishnan, Workability Limits in Cold Forging: Investigation of the Deformation Mechanics through FEA, Mechanics of Advanced Materials and Structures, ISSN 1537-6494, pp.213-224 (2007).

55. M.W.Fu, M.S.Yong, K.K.Tong and T.Muramatsu, A Metodology for Evaluation of Metal Forming System Design and Performance via CAE Simulation, International Journal of Production Research, ISSN 0020-7543, Vol. 44, No. 6, pp.1075-1092 (2006).

56. H.A.Joseph, Paul W.Cleary and Mahesh Prakash, SPH Modelling of Metal Forging, Fifth International Conference on CFD in the Process Industries CSIRO, Melbourne, Australia, Vol. 195, pp.1-6 (2006).

57. M.Skunca, P.Skakun, Z.Keran, L.Sidjanin and M.D.Matha, Relations between Numerical Simulation and Experiment in Closed Die Forging of a Gear, Journal Of Materials Processing Technology, pp.256-260 (2006).

58. Carlos C.António, Catarina F.Castro and Luísa C.Sousa, Eliminating Forging Defects using Genetic Algorithms, Materials and Manufacturing Processes, ISSN 1042-6914, pp.509-522 (2005).

59. Nagarajan Thiyagarajan and Ramana V.Grandhi, 3D Preform Shape Optimization in Forging using Reduced Basis Techniques, Engineering Optimization, Vol. 37, No. 8, ISSN 1042-6914, pp.797- 811 (2005).

60. Lirio Schaeffer, Alberto M.G.Brito and Martin Geier, Numerical Simulation using Finite Elements to Develop and Optimize Forging Processes, Steel Research International, pp.199-204 (2005).

61. Michael L.Chiesa, Reese E.Jones, Kenneth J.Perano and Tamara G.Kolda, Parallel Optimization of Forging Processes for Optimal Material Properties, Materials Processing and Design: Modelling, Simulation and Applications, NUMIFORM, pp.2080-2084 (2004).

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63. X.Lei and C.J.Lissenden, Finite Element Simulation of Ausforming of Austempered Ductile Iron Components, Journal of Manufacturing Science and Engineering, Vol. 123, pp.420-425 (2001).

64. W.Slagter, Forging Simulation Tool Based on Breakthrough Technology, Second International Conference on Design and Production of Dies and Mold, (2001).

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