Cold and Hot Forging: Fundamentals and Applications / Edited by Taylan Altan, Gracious Ngaile, Gangshu Shen

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Near-Net Shape Forging and New Developments / 329

Fig. 23.14

Helical gear cup formed using the MF-7500

[Nakano, 1997]

Fig. 23.13 Multislide forging press MF-7500 [Nakano, 1997]

23.5.1 Microforming

The trend in miniaturization allows the pro-

duction of cold-forged parts with dimensions

less than 0.04 in. (1 mm) range for electronics

and biomedical applications. These parts are

currently produced by 3-D etching and other

metal-removal processes. Microforming is a po-

tential process for mass production of net shape/

near-net shape microcomponents. However, for

microforming to be cost-effective and competi-

tive, a comprehensive knowledge pertaining to

the following factors is needed: scale effects/mi-

croplasticity, effect of microstructure on the pro-

cess, relative stiffness of the tooling, and process

control and capability.

With the aid of ﬁnite-element modeling

(FEM), the interrelationships between these

variables can be studied so as to provide guide-

lines for developing microforming processes. In

cooperation with industry, the Engineering Re-

search Center for Net Shape Manufacturing

(ERC/NSM) at Ohio State University has de-

veloped a microforming process for production

of surgical blades. Figure 23.18 shows an ex-

ample of 3-D FE simulations for a surgical blade

with initial blank thickness of 0.004 in. (0.1 mm)

and ﬁnal edge thickness of 0.0004 in. (0.01 mm)

[Palaniswamy et al., 2001].

In microforming, due to a high surface-to-vol-

ume ratio of parts, friction becomes even more

important than in conventional forging. Effects

of miniaturization on friction have been inves-

tigated by using the double-cup backward extru-

sion test, with oil as a lubricant (Fig. 23.19)

[Tiesler et al., 1999]. Comparisons between ex-

periment and simulation show that friction ef-

fects increase with a decrease in the size of the

specimen. The friction energy observed for

forming a 0.04 in. (1 mm) diameter billet was,

in proportion to total forming energy, 4 times

larger than that needed for forging a 0.16 in. (4

mm) diameter billet.

23.5.2 Orbital or Rotary Forging

Orbital or rotary forging is a very unique pro-

cess with a complicated die movement that can

be used to reduce axial load requirements for

axisymmetric or near-axisymmetric forging

operations. This process is not new and has been

used for small- or medium-batch production of

various round parts. The principle of orbital

forming can be seen in Fig. 23.20 and is also

discussed in Chapter 12, “Special Machines for

Forging,” in this book. The main advantage of

this process is the reduction of the forging load,

since deformation takes place incrementally.

Furthermore, a forging process that may require

330 / Cold and Hot Forging: Fundamentals and Applications

Fig. 23.16

Sectional view of the drive mechanism of the Aida Digital Servo Former. Courtesy of Aida Engineering Co. [Aida

Engineering]

Fig. 23.15 Multiaction forming press with the dies and the forged gear [Nakano, 1997]

multiple-station operations can be done on one

machine, although the cycle time is longer than

in upset forging.

Recently, orbital forming has been used by

various bearing and axle manufacturers for the

assembly of spindle drives (NSK Bearings, Ja-

pan). At the ERC/NSM at Ohio State University,

orbital forging simulations using DEFORM-3D

(Scientiﬁc Forming Technologies Corp.) were

conducted to study and develop a robust assem-

bly process of an automotive spindle and an

outer ring. Figure 23.21 shows the simulation

progression, which considers elastic and plastic

deformation, residual stresses, and quality of as-

sembly. This application illustrates the current

capabilities of FEM in simulating complex and

incremental cold forging operations to optimize

process conditions and product design.

Near-Net Shape Forging and New Developments / 331

Fig. 23.17 Some example settings of forming motions and speeds. Courtesy of Aida Engineering Co. [Aida Engineering]

Fig. 23.18

Microforming of surgical blades. Blank thickness

⳱ 0.004 in. (0.1 mm); ﬁnal blade thickness ⳱

0.0004 in. (0.01 mm) [Palaniswamy et al., 2001]

Machines for hot forging large wheels or

rings, using the incremental forming principle of

orbital forging, have been developed by several

machine tool builders. In these designs, the

punch or tool does not move orbitally but rotates

around a ﬁxed inclined axis, as shown in Fig.

23.22 [Husmann, 1999]. The part, located in a

die, is rotated and pushed vertically upward

while the inclined punch rotates. Thus, the ma-

chine is similar to a ring rolling mill that has a

lower die cavity that is hydraulically pushed up-

ward (Fig. 23.23).

Such machines are used to forge railroad car

wheels or forgings for large gears and near-net

shape formed spiral bevel ring gears for truck

differentials (Fig. 23.24).

23.6 Future of Forging Technology in

the Global Marketplace

Automotive companies, which account for a

very large portion of forged parts, are rapidly

expanding global operations in an effort to pro-

duce cost-effective vehicles. This has vast im-

plications for local automotive suppliers. A

global economy allows, in many instances, any

supplier that can satisfy part design requirements

to bid and obtain a contract, irrespective of the

geographic boundaries. This implies that the

current automotive suppliers will have to change

their production strategies to remain competitive

in the global marketplace.

Due to globalization, forging technologies are

diffusing across ﬁrms and across boundaries at

increasing rates, through channels such as over-

seas patenting, licensing, exchange of technol-

ogy-intensive goods, international investments,

and alliances. As a result of inexpensive labor,

production costs for simple parts are much less

expensive in developing nations. Therefore,

conventional cold forging operations will grad-

ually shift to developing nations for production

of low-tech components.

In order to succeed in the global marketplace,

forging suppliers from developed nations must

focus on production of high-value-added forg-

ings, ﬁnished parts, and subassemblies with the

aid of new developments such as advances in

the use of computer modeling in forging process

development, advances in press design, use of

innovative tool design for complex forging

operations, appropriate training in advanced

cold forging technologies, and information man-

agement in forge shops. While the process tool

and equipment design have been the subject of

extensive research and development, the ad-

vances in information management and person-

nel training cannot be ignored. These two as-

pects are just as crucial to ensuring a defect-free

part with the desired functionality as the tech-

nical developments.

23.6.1 Information Management in the

Forge Shop

Management of complex engineering infor-

mation in the forging environment plays a big

role in ensuring that the desired production out-

puts are met. A forging company should have

the ability to organize engineering knowledge

and properly disseminate useful information to

the respective departments for implementation.

It is necessary to store an abundance of data, to

be retrieved when and where desired. A number

of forging companies have gone global, with

332 / Cold and Hot Forging: Fundamentals and Applications

Fig. 23.20

Schematic representation of the orbital forging

process [Oudot et al., 2001]

Fig. 23.19 Double-cup extrusion test for determination of friction conditions in microforming [Tiesler et al., 1999]

branches in various locations. Thus, information

ﬂow becomes complex and difﬁcult to manage

efﬁciently.

To date, companies such as Plexus Systems

have developed computerized systems that can

assist the management of information ﬂow at

various departmental levels, e.g., inventory

tracking, shipping, receiving, engineering, pur-

chasing, etc. [Beatty, 1997]. At the engineering

departmental level, information management

systems can be helpful for storing and retrieving

data pertaining to tool designs, changing tool

materials, product speciﬁcation, process instruc-

tions, just-in-time jobs/rush jobs, process control

plan, tool life tracking, machine speciﬁcations

and drawings, press stress analysis, engineering

drawing management, and dimensional control

plans.

More sophisticated computerized information

management systems will continue to emerge,

and the forging companies will be compelled to

adopt these systems. Failure to do so might

hinder their chances of competing on the global

marketplace. The steady growth and develop-

ment of the worldwide web has prompted many

forging ﬁrms to reassess and redesign the way

they share critical business information [Beatty

et al., 2001]. The web can provide cold forging

companies with both operational and adminis-

trative beneﬁts that can improve the ﬁrm’s over-

all competitive position.

23.6.2 Training of Personnel

Due to global competition, the training of

metal forming engineers, who are expected to

plan and supervise the design and production of

parts and dies, becomes increasingly important.

Continuous improvements in forging technol-

ogy and application of recently generated re-

search and development results require that

engineers be continuously updated in new meth-

ods, machines, and process technology. Profes-

sional education in forging and metal forming is

necessary not only to upgrade the knowledge

level of practicing forging engineers but also

that of industrial, mechanical, and metallurgical

engineers who may be assuming new responsi-

Near-Net Shape Forging and New Developments / 333

Fig. 23.22 Fundamental principle of axial closed-die rolling [Husmann, 1999]

Fig. 23.21 Finite-element simulation of orbital forming (ﬁnite-element model and stress distribution) [Altan et al., 2003]

bilities in the forging industry [Vazquez et al.,

1999 and 2000].

In order to prepare engineers who will work

in high-tech forging companies, the current cur-

riculum given in most universities would have

to be restructured. It should be noted that most

of the material related to advanced forging tech-

nology taught at the university level is very basic

and may not be of signiﬁcant value to the high-

tech forging industry. Universities may be re-

quired to revise their design courses or develop

new ones that address real design issues pertain-

ing to forging. More importantly, for the course

to be successful and cost-effective, there is a

need to link universities to the forging industry

in areas such as process sequence development,

die/tool designs, press automation and design,

and computational tools such as computer-aided

engineering (CAE) software, CAD, and CAM

systems.

334 / Cold and Hot Forging: Fundamentals and Applications

Fig. 23.24

Bevel gear with teeth made on an axial closed-

die rolling machine [Husmann, 1999]

Fig. 23.23

Axial closed-die rolling machine, type AGW,

tool section [Husmann, 1999]

The following strategies for technology de-

velopment are being increasingly adopted by

competitive world-class companies to respond

to increased market globalization:

●

Use of CAE for virtual prototyping of com-

plicated high-value parts (microforming,

helical gear extrusion, constant velocity

joing (CVJ) inner races) and prediction and

elimination of forming defects such as laps

and chevron cracks

●

Design and implementation of advanced

forging presses and tooling for production of

complex components

●

The adoption and development of effective

computerized information management sys-

tems for cold forging operations

●

Life-long learning and training of engineers

to equip them with relevant knowledge that

can be readily applied to the dynamic tech-

nological environment of the 21st century

23.6.3 Concluding Remarks

The forging industry will continue to focus on

the development of tooling and processes for net

shape manufacturing of complex forgings, with

an emphasis on reduction of press/tool elastic

deﬂection, reduction of variation of process con-

ditions, achieving tight tolerances, and use of

special tooling/presses with speciﬁc functions

that enhance part quality. To facilitate product

and process development in minimal time and

expense, it is imperative that state-of-the-art

CAE capabilities be fully exploited. Further-

more, leading-edge forging companies continue

to develop strategies and capabilities for pro-

ducing “ready-to-assemble” parts and subassem-

blies for their customers. Thus, it is expected

that high-tech cold forging suppliers in devel-

oped nations can remain competitive by produc-

ing high-value-added parts and subassemblies

that require advanced technological expertise.

REFERENCES

[Aida Engineering]: “The Aida Digital Servo

Former: NC-1 and NS-1, Hy-Flex D Series,”

Aida Engineering Ltd.

[Altan et al., 2003]: Altan, T., Ngaile, G., Shir-

gaokar, M., “Cold Forging Technology in

Global Competition,” International Confer-

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June 2–4, 2003.

[Balendra et al., 1996]: Balendra, R., and Ou,

H., “Inﬂuence of Forming Press Elasticity on

the Accuracy of Formed Components,” Ad-

vanced Technology of Plasticity, Vol. 1, Pro-

ceedings of the Fifth ICTP (Columbus, OH),

Oct. 7–10, 1996.

[Beatty, 1997]: Beatty, R., “Advanced Infor-

mation Management in the Forge Shop,”

Journal of Materials Processing Technology,

Vol. 71, 1997, p 25–29.

[Beatty et al., 2001]: “Factors Inﬂuencing Cor-

porate Web Site Adoption: A Time-Based As-

sessment,” Information and Management,

Vol. 38, 2001, p 337–354.

[Doege et al., 1990]: Doege, E., and Silberbach,

G., “Inﬂuence of Various Machine Tool Com-

Near-Net Shape Forging and New Developments / 335

ponents on Workpiece Quality,” Annals of

CIRP, Vol. 39 (No. 1), 1990.

[Groenbaek et al., 1997]: Groenbaek, J., and

Nielsen, E.B., “Stripwound Containers for

Combined Radial and Axial Prestressing,”

Journal of Materials Processing Technology,

Vol. 71, 1997, p 30–35.

[Groenbaek et al., 2000]: Groenbaek, J., and

Birker, T., “Innovations in Cold Forging Die

Design,” Journal of Materials Processing

Technology, Vol. 98, 2000, p 155–161.

[Husmann, 1999]: Husmann, J., “High Speed

Ring Rolling and Closed-Die Rolling,” pre-

sented at the FIA Conference (Reno, NV),

May 1999.

[Ishinaga, 1996]: Ishinaga, N., “An Advanced

Press Design for Cold Forging,” Third Inter-

national Cold and Warm Forging Technology

Conference, SME and ERC/NSM (Columbus,

OH), Oct. 7–9, 1996.

[Kocanda et al., 1996]: Kocanda, A., Cacko,

R., Czyzewski, P., “Some Aspects of Die De-

formation in Net-Shape Cold Forging,” Ad-

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Oct. 7–10, 1996.

[Kondo, 1999]: Kondo, K., “Improvement of

Product Accuracy in Cold Die Forging,” Ad-

vanced Technology of Plasticity, Vol. 1, Pro-

ceedings of the Sixth ICTP, Sept. 19–24,

1999.

[Kondo, 2002]: Kondo, K., “Some Reminis-

cences of the Development of Precision Forg-

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ticity, Vol. 1, Proceedings of the Seventh

ICTP (Yokohama, Japan), Oct. 28–31, 2002.

[Meidert et al., 2000]: Meidert, M., and Hansel,

M., “Net-Shape Cold Forging to Close Tol-

erances under QS 9000 Aspects,” Journal of

Materials Processing Technology, Vol. 98,

2000, p 150–154.

[Nakano, 1997]: Nakano, T., “Presses for Cold

Forging,” Aida Engineering Ltd., JSTP Inter-

national Seminar of Precision Forging

(Osaka, Japan), The Japanese Society for

Technology of Plasticity, March 31 to April

1, 1997.

[Osakada, 1999]: Osakada, K., “New Methods

for Precision Forging,” Advanced Technology

of Plasticity, Vol. 2, Proceedings of the Sixth

ICTP (Nuremberg, Germany), Sept. 19–24,

1999.

[Oudot et al., 2001]: Oudot, H., and Faure, H.,

“Improvement of Precision in Cold Forged

Parts,” La Forge, No. 4, April 2001, p 27 (in

French).

[Palaniswamy et al., 2001]: Palaniswamy, H.,

Ngaile, G., and Altan, T., “Coining of Surgi-

cal Slit Knife,” F/ERC/NSM-01-R-26, Engi-

neering Research Center for Net Shape Manu-

facturing, 2001.

[Siegert et al., 2003]: Siegert, K., and Baur, J.,

“Cold Lateral Extrusion of Automotive Com-

ponents,” Proceedings of the International

Cold Forging Group Conference (Columbus,

OH), ERC/NSM, Sept. 2–4, 2003.

[Tiesler et al., 1999]: Tiesler, N., Engel, U.,

Geiger, M., “Forming of Microparts—Effects

of Miniaturization on Friction,” Advanced

Technology of Plasticity, Vol. 2, Proceedings

of the Sixth ICTP (Nuremberg, Germany),

Sept. 19–24, 1999.

[Vazquez et al., 1999]: Vazquez, V., and Altan,

T., “State of the Art Technology for Training

Engineers for the Forging Industry,” pre-

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[Vazquez et al., 2000]: Vazquez, V., and Altan,

T., “State of the Art Technology for Training

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[Yamanaka et al., 2002]: Yamanaka, M., and

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[Yoshimura et al., 1997]: Yoshimura, H., and

Wang, C.C., “Manufacturing of Dies for Pre-

cision Forging,” Nichidai Corporation, JSTP

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(Osaka, Japan), March 31 to April 1, 1997.

[Yoshimura et al., 2000]: Yoshimura, H.,

Wang, X., Kubota, K., Hamaya, S., “Process

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SELECTED REFERENCE

●

[Yoshimura et al., 1983]: Yoshimura, H.,

and Shimasaki, S., “A Study of Enclosed Die

Forging,” Journal of the JSTP, 1983, p 24–

30.

Index

Accuracy

in forging 112

of mechanical presses 126–128(F, T)

of screw presses 133

Aircraft/aerospace applications

isothermal and hot-die forging 257–275(F, T)

process modeling for 199(F), 201–202, 203(F), 204(F),

205–206(F)

Aluminum and aluminum alloys

aircraft component, process modeling for 203(F),

205–206

cold forging of 213–215(F, T)

ﬂow stress-strain 30(F), 40(T), 44(T)

hot forging temperatures 163(T)

load-displacement curve 29(F)

lubrication 71(F), 73(T), 75(T), 214–215(F)

preform dies 174, 175(F, T)

ring testing 65(T), 87–89(F, T)

Analysis. See also Finite difference analysis; Finite

element analysis/modeling; Inverse analysis; Slab

analysis

for ﬂow stress and friction 83–89(F, T)

for forging operations 91–105(F, T)

Automated mesh generation 196

Automotive applications

and globalization 331–334

process modeling for 200(F), 201(F), 202–205(F),

239(F), 240(F), 241, 242(F)

Barreling, and ﬂow stress errors 33–35, 36(F), 37(F),

38(F), 238

Bending, load vs. displacement 109(F)

Biaxial stress 19–20(F)

Billets

and die failure 297–299

lubrication 214–215(T)

as process variable 8(F)

separation and shearing 151–157(F), 299

Blanking, load vs. displacement 109(F)

Blocking. See Dies, preform

Carbon steels

hot forging temperatures 163(T), 214(T)

lubrication 71–73(F, T), 74(T)

preform dies 174(T), 175(F)

Casting, of dies 292

Cemented carbides, for tooling 286–287, 288(T)

Ceramic dies 285

Closed-die forging. See also Impression-die forging

load vs. displacement 109(F), 110(F)

overview 10(F), 11(F)

Coining

load vs. displacement 109(F)

overview 14(F)

Cold forging

advantages 212–213

billet preparation 214(T)

dies 228–229, 230(F), 286–289(T)

ﬁnite-element modeling 307–311(F, T)

lubricants for 70–73(F, T), 214–215(F, T)

materials for 213–214(T)

overview 211–212(F)

process design 229–230, 231(F), 232(F)

process modeling 237–246(F)

system variables 213(F)

tooling 225–228(F), 230–233(F), 286–289(T)

Compression testing. See also Ring testing

errors 33–35, 36(F), 37(F), 38(F)

and ﬂow stress 26(F), 27(F), 28(F), 29–35(F, T), 36(F),

37(F), 38(F)

for microstructure model development 247–248

press slide parallelism 32–33, 34(F), 35(T)

specimen preparation 28(F), 31–32

tooling 27(F)

Computer-aided design (CAD) system, and FEM

simulation 244–245(F)

Connecting rod

load prediction 177–182(F, T)

process modeling for 206–207(F)

Copper and copper alloys

ﬂow stress-strain 40(T), 45(T)

hot forging temperatures 163(T)

lubrication 73(T), 75(T)

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338 / Cold and Hot Forging: Fundamentals and Applications

Crank presses. See Mechanical presses

Cross rolling. See Transverse rolling

Deformation. See Homogeneous deformation; Plastic

deformation; Superplastic deformation

Deformation energy 57

Deformation zone, as process variable 8(F), 9

Dies. See also Closed-die forging; Enclosed-die forging;

Impression-die forging; Open-die forging

advances in 325(F)

casting of 292

ceramic 285

cold forging 228–229, 230(F), 286–289(T)

extrusion 228–229, 230(F)

failure of 231–232, 295–317(F, T)

ﬁnisher design of, 165–167

ﬁnite-element modeling 307–316(F, T)

and friction/lubrication 70, 304

for isothermal and hot-die forging 264–267, 270(F)

lubrication 74(T)

machining of 291(F), 292, 320–321(F)

manufacture of 289–292(F, T), 303, 320–321(F)

materials for 277–289(F, T), 301–303

precision 320–321(F)

preform 171–177(F, T)

as process variable 8, 9

surface ﬁnish 303–304

surface treatments 292(T), 303

Double cup backward extrusion testing, for lubricity

77(F), 78–80(F, T), 243(F)

Eccentric presses. See Mechanical presses

Efﬁciency factor 111

Electro-upsetting 10, 11(F), 142–143, 145(F)

Electrochemical machining, of dies 292

Electrodischarge machining, of dies 291(F), 320–321(F)

Enclosed-die forging 323–325(F)

Energy requirements 108–109, 111, 123–124,

131–133(F)

Engineering strain 23(F)

Environmental factors 4, 8(F)

Equipment. See also Dies; Forging machines; Hammers;

Presses; Shearing

and die failure 299–301

as process variable 8(F), 161–162

selection, process modeling for 199(F), 201

Exhaust valves, FEM analysis of 314–315(F, T)

Extrusion

backward 11, 12(F), 109(F), 218–225(F, T), 308–309(F)

dies 228–229, 230(F)

double cup backward extrusion testing 77(F), 78–80(F,

T), 243(F)

forward 10–11, 12(F), 109(F), 218–225(F, T), 239(F),

240(F), 307–308(F, T)

friction and ﬂow stress 221–222

load and energy 218–220(F), 222–225(T)

lubrication 219

open-die 221(F)

tooling 225–228(F), 230–233(F)

trapped-die 220–221(F)

Failure, of dies 231–232, 295–317(F, T)

Fatigue, and die failure 301–303(F, T)

Finite difference analysis 92(T)

Finite element analysis/modeling 75(F), 83–89(F, T),

92–93(T), 98–104(F), 185, 189–190, 193–209(F),

237–246(F), 307–316(F, T)

Flash 10(F), 159–160, 161(F), 167–169(F)

Flow rules, and plastic deformation 55–56, 96

Flow stress

average values 48(T)

data representation 36–48(F, T)

estimation 178–181(T), 190(T), 191, 221–222

and forgeability 25–49(F, T), 161, 163(F)

inverse analysis 83–89(F, T), 238(F)

of nickel-base superalloys 266(F)

of titanium alloys 264(F), 265(F)

Forgeability, and ﬂow stress 25–49(F, T), 161, 163(F)

Forging machines. See also Hammers; Presses

advances in 326–328(F)

principles of 107–113(F, T)

special 141–150(F)

Forging processes. See also Cold forging; Hot forging;

Metal forming; Near-net shape forging; speciﬁc

forging processes

analysis methods for 91–105(F, T)

future developments 331–334

innovations 328–331(F)

load and energy requirements 108–109(F), 110(F), 111

system variables 7–9(F), 91, 160–161, 162(F), 322(F),

323

temperature and heat transfer in 59–66(F, T)

types of 9–14(F)

Fracture mechanisms, in die failure 296

Friction

estimation of 181, 221–222, 238

in forging 67–81(F, T)

inverse analysis 83–89(F, T)

laws 69

as process variable 9, 162, 196

Gatorizing 258

Gears

cold forging of 211(F)

process modeling for 200(F), 201(F), 202–203,

207–208(F)

punch failure 310–311(F)

Geometry

and manufacturing process 2

and process modeling 194–195, 237

as process variable 8, 9, 159, 160(F), 164–165, 166(F)

simpliﬁed model 187(F), 190–191

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Index / 339

Glass, as lubricant 74(T), 268–269, 271(F)

Globalization 331–334

Golf ball mold cavities, modeling of 239–241(F)

Grain growth 251–252, 253(F)

Graphite, as lubricant 74(T), 214

Hammers/hammer forging 110, 111(T), 135–139(F),

198–200(F), 300

Heading 13–14(F)

Heat checking, of die steels 283(T), 284(T)

Heat transfer, in metal forming 59–66(F, T), 162–163,

196

Heat treatment. See also Postforging heat treatment

of die steels 285

process modeling for 207–208(F)

HERF machines 111(T)

Hobbing

of dies 291–292

of golf ball mold cavities 239–241(F)

overview 11, 12(F)

Homogeneous deformation 21–23(F), 56(F)

Horizontal forging machines 144–145, 147(F)

Hot-die forging 257–275(F, T)

Hot forging

advantages 212–213, 233

die and tool materials for 277–285(F, T)

ﬁnite-element modeling 311–316(F, T)

lubricants for 73–74(F, T), 75(T)

overview 211, 233–234

process and machine variables 108(F)

temperatures 163(T)

Hydraulic presses 110, 111(T), 115–120(F), 263–264,

267(F)

Impression-die forging. See also Closed-die forging

load estimation, simpliﬁed method 185–192(F, T)

process design 159–183(F, T)

process modeling using FEA 193–209(F)

systems approach 8(F)

Information management 331–332

Inverse analysis, for ﬂow stress and friction

determination 83–89(F, T)

Ironing 14(F)

IsoCon process 258

Isothermal forging 11–12, 13(F), 257–275(F, T)

Jet engine disks, process modeling for 199(F), 201–202

Knockout pin, ﬁnite-element modeling of 309–310(F)

Knuckle-joint presses. See Mechanical presses

Lead and lead alloys, ﬂow stress-strain 47(T)

Load

in extrusion 218–220(F), 222–225(T)

in impression-die forging 167–171(F), 181–182(T),

185–192(F, T)

prediction, for connecting rod 177–182(F, T)

requirements 108–109(F), 110(F), 111, 123–124(F),

131–133(F)

Lot size, and die design 164

Low-alloy steels

for hot forging 278(T)

hot forging temperatures 163(T)

lubrication 214(T)

preform dies 174(T), 175(F)

Lubrication

and die failure 304

evaluation methods 74–80(F, T)

in extrusion 219

in forging 67–81(F, T)

in isothermal and hot-die forging 268–269, 271(F)

mechanisms 68–69(F)

as process variable 8, 9, 162

Machining, of dies 289–291

Magnesium and magnesium alloys

ﬂow stress-strain 47(T)

hot forging temperatures 163(T)

lubrication 75(T)

Manufacturing processes

characteristics of 2–4

classiﬁcation of 1–2

metal forming 1–5

Maraging steels

for dies 283–284(T)

hot forging temperatures 163(T)

Material characterization 8–9, 196, 237–238

Mechanical presses 111(T), 120–131(F). See also

Horizontal forging machines

Mesh generation, automated. See Automated mesh

generation

Metal forming

analysis methods 83–85(F), 91–105(F, T)

and ﬂow stress 25–49(F, T)

friction and lubrication 67–81(F, T)

and heat transfer 59–66(F, T)

in manufacturing 1–5

plastic deformation 17–23(F), 51–57(F)

Microforming 329, 331(F), 332(F)

Microstructure modeling, in superalloy forging 199(F),

200, 201–202, 247–255(F, T)

Modeling. See Microstructure modeling; Process modeling

Mohr circles 53(F), 54(F)

Molybdenite, as lubricant 74(T), 214

Molybdenum and molybdenum alloys, hot forging

temperatures 163(T)

Cold and Hot Forging: Fundamentals and Applications (#05104G)