Introduction
Basic Knowledge Forgings – Significance, Design, Production, Application
Forgings – Significance, Design, Production, Application 1 Directory
Page number Subject
30 Preface 4 - 80 Forging History 9 - 11 Production Statistics 12 - 14 Forging Materials 15 - 16 Grain-Flow 17 Tool Design and Profitability 18 - 19 Accuracy of Forged Pars 20 The most important forging processes 21 - 28 Forging Machinery 29 - 31 Automation 32 - 33 Pre-Forming 34 Ring Rolling 35 - 36 Open-die Forging 37 Special Process Hot Forging 38 Special Process Warm Forging 39 - 47 Cold Forging 48 - 52 Process Stages 53 Process Combinations 54 - 55 Tools 56 - 57 Heat Treatment 58 Surface Treatment 59 - 66 Quality Assurance and Material Testing 67 Machining Process 68 Forged parts in competition 69 - 81 Diversity of Forms 82 - 84 Applications 85 Diversity in Forging Technology 86 Optimization of Components NOTE: 87 - 90 Development Chain Please switch from standard view to 91 - 94 Simulation screen presentation to be able to 95 Sources of Illustrations and Information activate and use the links. 96 Imprint 97 - 101 Bibliography 102 Annex
Forgings – Significance, Design, Production, Application 2 Preface
Dear Readers, Ladies and Gentlemen, This presentation of the forging industry is designed to offer you an easily comprehensible insight into the highly interesting and, for the economy, tremendously important world of hot and cold forging. Even in the age of the Blackberry, IP-TV, Web 2.0 and all of the other colourful accomplishments that our modern world of the media presents us with every day, machine engineering and plant construction – which is dependent on forged components by massive forming – is and will remain one of the most important pillars of our present-day prosperity. Without high-strength, forged metal components, the economic and technical development that we have experienced over the last hundred years would not have been possible. Electricity and mobility in the form of motorised vehicles of all kinds are just two of the multifarious fields of application for modern forged parts. And also in the future, this technology will be used to an ever increasing extent: Thanks to worldwide economic growth in recent years, the export of forged parts from Germany to all parts of the world has been steadily increasing. Furthermore, the need to reduce CO2 emissions will also boost the demand for hot and cold forged parts. The use of renewable energy by way of wind and hydroelectric power plants, economical combustion engines with high combustion efficiency and low frictional losses, as well as efficient dual clutch transmissions are merely a few of the many examples of environment protection which would be impossible without forged components. To enable the development and application of these often very complex and, technically speaking, highly demanding components, an increasing use of cutting edge computer technology and simulation software is being made in this branch of the industry. This presentation “Basic Knowledge: Forgings – Significance, Design, Production, Application” is an “open” PowerPoint File. This means that it is possible for you to take elements from it for teaching purposes for your own presentation. By using the search function in PowerPoint, you are able to find the terms you need from the presentation in a few seconds. Besides the clear, summarised texts on the individual pages, many pages also show more detailed, full text descriptions that will provide you with further background information. Via directory you are able to switch within the subjects.
Hagen, 01/04/2011 Dr. Stefan Witt Chairman of the Board Industrieverband Massivumformung e. V. German Association of the Forging Industry
Back to directory >> Forgings – Significance, Design, Production, Application 3 The art of forging is already 6000 years old
Forging is one of mankind's oldest technological processes.
In 4000 BC metals were already being worked by smiths
The first copper-alloys appeared around 2500 BC - we call this the Bronze Age
Sketch from the pictures in the grave of Rechmiré, vizir in the 18th Dynasty (ca. 1450 BC)
Back to directory >> Forgings – Significance, Design, Production, Application 4 Forging through the ages I
Between 700 and 500 BC iron replaced bronze.
The smelting of the iron ore and the forging process were one unit until the 13th or 14th centuries.
Mediaeval smelting furnace with accompanying smithy. The furnace and the smith's fire both used charcoal as fuel in those days.
Back to directory >> Forgings – Significance, Design, Production, Application 5 Water and steam replace muscle power
Water-powered iron hammer (ca. 1780) Steam hammer "Fritz" in Essen (ca.1860)
Back to directory >> Forgings – Significance, Design, Production, Application 6 The start of drop forging
The smiths of those days used hammers driven by transmission shafts to produce a wide range of forged parts for the railways, for the car industry and for agricultural machinery
View of the production area of the Schmiedag Range of products of the Schöneweiss company in Hagen (ca.1910) drop-forging works (ca.1910)
Back to directory >> Forgings – Significance, Design, Production, Application 7 Development of forging technology
The development of drop forging made possible:
- increasing batch sizes for the automotive industry
- further development of and specialization in steel types
- new technologies for tool production
- development of new machine types, new production processes and combinations of processes, and automation
View of a production facility with a linked automated forging line
Back to directory >> Forgings – Significance, Design, Production, Application 8 Production figures - German forging sector
Production of forgings in 2010
Manufacturing group Production in '000 tonnes Proportion in %
Drop forging industry 1280 65
Flange manufacturers 68 3,5
Pipe-fittings producers 95 4,8
Cold-forging manufacturers 175 8,9
Open-die forgers 350 17,8
Total forging production 1968 100
Almost two-thirds of the total forging output comes from the drop-forging sector.
Back to directory >> Forgings – Significance, Design, Production, Application 9 Markets for forged products I
More than a third of all forged parts are exported. The automotive sector, together with system producers (tier one suppliers) receives more than 80% of the total production.
Mechanical engineering Others 5% 10%
Export 35% System suppliers 36% Domestic 65% Cars 34% Trucks 15%
Percentages of steel forged parts delivered in 2009, in tonnes.
Back to directory >> Forgings – Significance, Design, Production, Application 10 Current status of drop-forging technology
Germany is the number two producer world-wide. Production in 2008 was 3,000 000 tonnes.
Back to directory >> Forgings – Significance, Design, Production, Application 11 Forgeable materials I
All metals and metal alloys, with very few exceptions, are suitable for forging. There is a range of more than 2,500 types of steel from which to choose to achieve the most economical production process.
Steel group Standard Mild steels DIN EN 10222-1 DIN EN 10250-1/-2 Heat-treating steels DIN EN 10083-1/-2/-3 Case-hardening steels DIN EN 10084 Nitriding steels DIN EN 10085 Steels for flame- and DIN EN 10083-1/-2/-3 induction-hardening Ball- and roller- DIN EN ISO 683-17 bearing steels High-temperature DIN EN 10269 steels DIN EN 10222-1/-2 Tough-at-low- DIN EN 10269 temperature steels DIN EN 10222-1/-2/-3 Stainless steels DIN EN 10222-5 DIN EN 10250-1/-4 AFP-Steels DIN EN 10267 Forming characteristics of various material groups
Back to directory >> Forgings – Significance, Design, Production, Application 12 Forgeable materials II
Steel group Standard Application
Mild steels DIN EN 10222-1 Machine parts with low dynamic loading and tensile strength requirements DIN EN 10250-1/-2
Heat-treating steels DIN EN 10083-1/-2/-3 Machine parts and automotive components with higher dynamic or static loading such as steering knuckles, crank shafts, drive shafts and safety critical parts for automobiles and for use in cable cars and aerial ropeways.
Case-hardening steels DIN EN 10084 Case-hardened gearbox and drive-line components such as gears, shafts, toothed Nitriding steels DIN EN 10085 parts and wear-resistant forming tooling.
Steels for flame- and DIN EN 10083-1/-2/-3 Very high wear-resistance for chassis components, for tracked vehicles, conveyors induction-hardening for the mining industry, very large roller bearings with hardened tracks
Ball- and roller-bearing DIN EN ISO 683-17 Special steels for hardened roller bearing rings and bodies. The steels achieve their steels very high hardness values by good through-hardening.
High-temperature steels DIN EN 10269 High-alloyed steels for gas turbine engines, burners and industrial furnaces, forming DIN EN 10222-1/-2 tooling and dies.
Tough-at-low- DIN EN 10269 Machine parts for use at sub-zero temperatures, automotive components for use in temperature steels DIN EN 10222-1/-2/-3 extreme conditions, springs and applications with high dynamic loading.
Stainless steels DIN EN 10222-5 Fittings for the chemical and food industries, components for marine use, fittings for DIN EN 10250-1/-4 the building industry, cutlery and household wares, screws and fasteners and wire ropes for use in damp conditions.
AFP-Steels DIN EN 10267 Application as with heat-treated steels but more cost-effective for engine and chassis components such as connecting rods, crankshafts, steering components, drive shafts and axles.
Back to directory >> Forgings – Significance, Design, Production, Application 13 Forgeable materials III
For special applications, materials such as titanium, aluminium, nickel alloys and AFP-steels are also forged.
Medical components Front-wheel swing Heat-resistant turbine Connecting rods for (Hip joints) in titanium bearing blades in nickel alloys truck engines in AFP steel (precipitation hardening ferritic-perlitic steel)
Back to directory >> Forgings – Significance, Design, Production, Application 14 Grain-flow I
Grain-flow takes place during rolling through the longitudinal alignment of segregations in the steel. In an optimal forming process, this grain-flow is retained and runs parallel to the surface of the component.
Four cylinder crankshaft with counterweights
Optimal grain-flow increases the dynamic strength of the component
Back to directory >> Forgings – Significance, Design, Production, Application 15 Grain-flow II
The grain-flow (with the segregated core of the raw material) runs from left to right through the component. Grain-flow breaking out of the side would result in an undesirable stress-raising notch effect.
Automobile gearbox shaft cold The gear profile is milled in the two collars. In the area of the formed in two stages teeth, the grain-flow is perpendicular to the direction of the load
Back to directory >> Forgings – Significance, Design, Production, Application 16 Tool design and profitability
The required quantities and batch sizes Small quantity Medium quantity High quantity determine the form of Low degree of Moderate degree of High degree of the tooling and the most adaptation to the adaptation to the adaptation to the economical production finished form finished form finished form process to use. Expensive tooling and/or several pre-forming tools are easier to justify for high quantities. The production costs can be lowered by process Costs optimization and automation. The total costs can also be Finished part Machining Finished part Machining Finished part Machining lowered by reducing the Production Production amount of machining Production As-forged As-forged As-forged Material Material required. part Material part part
Tooling Tooling Tooling
Dependence of the costs of forgings and of finished parts on the quantity produced
Back to directory >> Forgings – Significance, Design, Production, Application 17 Accuracy of forged parts
= Achievable with conventional production equipment Precision forged pair of bevel = Achievable using special methods or in exceptional cases gears with helical teeth and Generally, for steel drop-forgings the dimensional clutch dogs tolerances laid down in DIN EN 10243-1 apply. Closer tolerances can be agreed individually between manufacturer and customer. For steel open-die forgings, special tolerances apply.
Back to directory >> Forgings – Significance, Design, Production, Application 18 Accuracy of forged parts
The tolerances that are technically possible for forgings depend on
• the position of the dimension; thickness dimensions which are formed across the parting line of the dies require larger tolerances than height and diameter dimensions contained entirely in one die-half
• the complexity of the forging; here a distinction is made depending on the fine detail of the forging
• the weight and size of the forging
• ease-of-forging, depending on the type of material
The calculation of tolerances is laid down in DIN EN 10243-1 Tighter tolerances are possible using extra measures and must be agreed with the manufacturer.
Back to directory >> Forgings – Significance, Design, Production, Application 19 The most important forging processes
Five main methods are used Gripper jaws in forging: Upper die Upsetting punch - Drop-forging - Upsetting Lower die - Extrusion - Open-die forging
- Ring rolling Workpiece
Workpiece Drop-forging Upsetting
Punch Main roll
Saddle Axial rolls Die Mandrel Workpiece Workpiece
Workpiece Saddle
Extrusion Ejector Open-die forging Ring rolling All hot-forming processes take place at around 1,200C
Back to directory >> Forgings – Significance, Design, Production, Application 20 Forging machinery I
Three main types Main types of machine Of machine are used for Forging: - energy- dependant press-force- energy-dependant machine-stroke-dependant - press-force- dependant dependant - machine- stroke- with linear with rotary dependant stroke working motion
Double-acting Eccentric presses hammers Ring rolling Hydraulic Crank presses Counterblow Reducer rolling presses Upsetting hammers Cross rolling machines Screw presses
Back to directory >> Forgings – Significance, Design, Production, Application 21 Forging machinery II
Presses
energy-dependant press-force-dependant machine-stroke-dependant
The machine types are shown depicting the limiting conditions at the end of the working stroke. Each machine type has its advantages and disadvantages and is specially chosen depending on the part to be produced.
Back to directory >> Forgings – Significance, Design, Production, Application 22 Hammers for drop forging I
1 Power unit 1 2 Ram
2 3 Upper die
4 Lower die 3 5 Anvil block 4 6 Vibration damper elements 5
6
The double-acting hammer To dampen the vibrations, the (energy-dependant) is hydraulically hammer is mounted on spring or pneumatically driven. elements
Back to directory >> Forgings – Significance, Design, Production, Application 23 Hammers for drop forging II
Drive 1 1 2 Ram 2 3 Upper die
3 4 Hammer frame 5 Lower die 4 6 Lower ram
5 7 Hydraulic ram clutch The counterblow hammer is driven 6 pneumatically – ideal for large pieceweights 7
The counter movements of the ram reduce vibrations
Back to directory >> Forgings – Significance, Design, Production, Application 24 Presses for drop forging I
Frame 8 1 6 2 Punch slide
9 3 Punch guide 4 Screw spindle
7 5 Spindle nut 4 6 Clutch
5 7 Flywheel bearings
8 Spindle brake Hydraulic
9 equipment 1 10 Ejector
11 11 Pneumatic 3 counterweight 2 10
The screw press is suitable for A large amount of forming energy long runs and can be automated is available
Back to directory >> Forgings – Significance, Design, Production, Application 25 Presses for drop forging II
1 Hydraulic cylinder
5 2 Ram
1 3 Table
2 4 Machine frame 4 Electric motors 6 5 6 Walking beam
8 automation 7 Forming station
8 Material feed 3
7
The hydraulic press offers a constant It is particularly suited for hot- and maximum press force over the whole cold-extruding with a long working stroke stroke
Back to directory >> Forgings – Significance, Design, Production, Application 26 Presses for drop forging III
5 9
6
3
7
8 2 4 10 1
The eccentric press is machine stroke 1 Frame 6 Counterweight dependant and readily automated at high 2 Ram 7 Ram adjustment rates of production (strokes per minute) 3 Connecting rod 8 Reduction gearbox 4 Ram guide 9 Double-helical gearing 5 Clutch and brake system 10 Upper and lower ejector
Back to directory >> Forgings – Significance, Design, Production, Application 27 Presses for drop forging IV
8 1
6
7
9
2 5
3 4 10
The wedge press is tip-resistant and is 1 Frame 6 Counterweight ideal for off-centre forging 2 Ram 7 Ram adjustment 3 Wedge 8 Reduction gearbox 4 Ram guide 9 Double-helical gearing 5 Clutch and brake system 10 Upper ejector
Back to directory >> Forgings – Significance, Design, Production, Application 28 Automation of important forging equipment
1 3
8
2 5
6 4 7
Walking beam system Tongs arm system
1 Feed gripper 4 Walking beam unit 1 Feed gripper 5 Tongs slide 2 Power unit 5 Press frame 2 Transport grippers 6 System drive unit 3 Transport 6 Lower die 3 Lower die 7 Transverse slide
grippers 4 Tongs arms 8 Press framer
Back to directory >> Forgings – Significance, Design, Production, Application 29 Automated multi-die hot-forging presses
Multi-die presses for hot forging (e.g. Hatebur) are fully automatic in operation. The speed is continuously variable and large numbers of pieces can be produced
Automatic multi-die hot-forging press with Tool area of a multi-die hot forging press with inductive pre-heating equipment four dies
Back to directory >> Forgings – Significance, Design, Production, Application 30 Automated production line
A series of eccentric presses linked to form a production line using robots – the operator is keeping an eye on the whole process
Back to directory >> Forgings – Significance, Design, Production, Application 31 Pre-forming 1
1 10 9
2 8
7
3
4 5 6
1 6 Roll drive with automatic Length compensation cylinder backlash compensation Reducer rolling, through the distribution 2 of material, optimises flash and saves Servo-controlled electric transverse feed Water-cooled brake and 7 asbestos-free brake pads raw material when forging 3 Crank-rocker drive mechanism 8 Clutch with asbestos-free pads
4 Eccentric mounting of the lower roll for Flywheel with large energy reserve adjusting the distance between rolls 9
10 Automatic rocker arm 5 Feeder device to position the workpiece between the grippers of the manipulator
Back to directory >> Forgings – Significance, Design, Production, Application 32 Pre-forming 2
4
1
2
3
Cross-wedge rolling is suitable for parts with a 1 Roll segments circular cross-section and is used to distribute 2 Work rest material in one production step. For simple shafts it can be suitable for the production of 3 Machine frame finished parts. 4 Electric motors
Back to directory >> Forgings – Significance, Design, Production, Application 33 Ring rolling
Seamless rolled rings are typical products of the forging industry.
Ring rolling can produce seamless rings with square and rectangular cross sections as well as rings with internal and/or external profiles.
The largest diameter which can be produced today is approx. 8 metres Typical radial-axial ring rolling machine
Back to directory >> Forgings – Significance, Design, Production, Application 34 Open-die forging I
Open-die forging is the oldest method of forging. It is used for one-off workpieces, short production runs and for very heavy parts
1 3
2
4 5
Open-die forging press with underfloor- mounted equipment and an integrated rail- Automated open-die forging using underfloor- mounted manipulator mounted equipment with a freely movable 1 Forging press 4 Forging saddle manipulator 2 Workpiece 5 Forging saddle
3 Manipulator
Back to directory >> Forgings – Significance, Design, Production, Application 35 Open-die forging II
Longitudinal forging machine with four radially-arranged tools.
1 The arrangement of the tooling on a longitudinal 2 forging machine for high precision rotary swaging of hollow parts with an optimized weight 3 4 5
1 Manipulator 4 Workpiece
2 Forging tools 5 Manipulator
3 Forging machine
Back to directory >> Forgings – Significance, Design, Production, Application 36 Special forging processes
These special processes are Anvil plate Contact electrode Upper tool largely used for the mass Hydraulic cylinder production of families of similarly Workpiece shaped parts Lower die
Workpiece
Electric upsetting Die rolling
Wobble bell Tool segment Roll segment Base tool
Upper die Workpiece Workpiece Workpiece
Roll segment
Lower die Tool segment Tool segment Base tool Cross-rolling Wobble forging Swaging
Back to directory >> Forgings – Significance, Design, Production, Application 37 Special process warm forging
Shaft for a tripod CV-joint manufactured using a combination of warm forging and cold sizing.
A drive shaft component manufactured using a combination of warm forging and cold sizing. As-forged part on the left, finished part on the right
Back to directory >> Forgings – Significance, Design, Production, Application 38 Cold Forging
Definition: Cold forging = no heating of the workpieces and/or forming starts at room temperature.
Most producing companies are medium-sized companies.
up to 49 employees 50 – 199 employees
200 – 399 employees 400 and more employees
Back to directory >> Forgings – Significance, Design, Production, Application 39 Cold Forging
Cold forging Worldwide 2008 Cold forging Europe-wide 2008
450 North America 399 Europe
160 China 298 Germany
122 Japan 50 France
40 Russia 160 UK
25 Australia 122 Spain
17 India 19 Rest
Annual production in thousands of tons Annual production in thousands of tons
German share German share Globally: 24.6% Europe-wide: 74.7%
Back to directory >> Forgings – Significance, Design, Production, Application 40 Cold Forging
Advantages Difficulties
Near-net-shape forming Extensive treatment of the workpiece
Higher dimensional accuracy than with Less degree of forming than with hot forming forged parts
Very high degree of material utilisation Complex forms difficult to realise
No scaling Higher tool expenditure
High surface quality
High workpiece strength through strain hardening
Expedient grain flow as with hot forming
No heating necessary
Very suitable especially for large quantities
Back to directory >> Forgings – Significance, Design, Production, Application 41 Cold Forging
Typical methods and special methods Essential cold forming processes are: Tapering, extruding, upsetting, thread rolling, and ironing
Forward extrusion Drawing Backward can extrusion Rotary swaging
movable roll jaw
fixed roll jaw
Raw material on which thread is applied Ironing Upsetting Thread rolling
Back to directory >> Forgings – Significance, Design, Production, Application 42 Cold Forging
Exemplary parts
Gear shaft Drive junction Shaft housing (car tie Gearshift level 5000g (cardan shaft) |1000g rod) | 290g (PRINZ) | 209g
Steering fork Pinion Clutch wheel Dowel screw (automotive) | 160g (acrument) | 137g (bicycle) | 18g (KAMAX) | 13g
Back to directory >> Forgings – Significance, Design, Production, Application 43 Cold Forging
Special methods
Hot forging Cold forging
High formability High precision
Combination of hot and cold forming Pinion cage Combination of hot and cold forming
Primary forming at high Part-conform finished sizes and temperature allows high degrees surface qualities can be achieved of forming in cold state
• The methods to be chosen depend on the process chain • Criterion for an expedient combination: Mere cold forming would require at least one process annealing step Fixed joint • Direct competition: hot forming and machining Combination of semi-hot and hot forming
Back to directory >> Forgings – Significance, Design, Production, Application 44 Cold Forging
Materials and machines Types of presses: Drive type: • Mechanical presses • Hydraulic presses • Servomotor presses
Number of steps:
Coil • Multi-step presses www.asia.ru • Single-step presses
Processable types of materials: Design: Hydraulic press • Steel • Horizontal • Non-ferrous heavy metals • Vertical • Aluminium • Stainless steel
Blank forming: • Sections • Coils
Tools of a multi-stage press Classic cold forming material: www. zeller-gmelin.de Preferably non-alloyed case hardening and tempering steels with a C-content of max. 0.5 % (alloy shares at most 5%).
Back to directory >> Forgings – Significance, Design, Production, Application 45 Cold Forging
Process chain
Forming mostly takes place in several stages
Pre-treatment Annealing Coating Forming Post-processing
• Shearing • Lubricant carrier layer • Coating removal • Blasting (e. g.: Zink phosphate) • Annealing • Lubricant • Machining (e. g.: soap, MoS2) • Thread rolling • New lubricant systems
Back to directory >> Forgings – Significance, Design, Production, Application 46 Cold Forging
Current trends and developments
• Function integration: Integration of additional functions in parts • New, more solid materials • Ready-to-fit parts • Reducing the economic minimum quantity • Phosphate-free forming / alternative lubricants
Back to directory >> Forgings – Significance, Design, Production, Application 47 Processes prior to forging I
Depending on the hardness of the material, its cross-section and the cut-off rate required, various cut-off systems are used for making blanks .
Sawing offers the Cold shearing has the Hot shearing is independent of advantage of the greatest advantages of low material material hardness and is well precision and the largest wastage and short cycle times. suited for integration into high cross-sections, but has The disadvantage is that the speed automated forging lines. higher material wastage, cross-sectional area is limited longer cycle times and (to max. 150mm) higher costs.
Back to directory >> Forgings – Significance, Design, Production, Application 48 Processes prior to forging II
Inductive heating equipment
Inductive heating of cut-off blanks to a forging temperature of approx. 1,250 C
Back to directory >> Forgings – Significance, Design, Production, Application 49 Process stages in manufacture
Production stages of a drop-forged crankshaft form left to right:
- Steel blank - Pre-formed blank - Rough-forged part - Finish-forged part - Forging and trimmed - flash - Crankshaft
Lower rough forging die Lower finish forging die Trimming tool Trimming punch
Back to directory >> Forgings – Significance, Design, Production, Application 50 Process steps after forging
Flash and piercing-slugs are Forging with flash Arm after removed by trimming and hole- bending and Trimming die Forging sizing piercing. Trimming punch
Post-forging processes save Arm before bending material and processing costs, Flash reduce the dimensional variation Forging Big and little and make possible undercuts. ends in as forged condition
Piercing punch Big and Forging with little ends inner flash punched to size Forging
Before Piercing die expanding
Forging After expanding
Forging Internal flash
Trimming and piercing Subsequent forming (e.g. bending, sizing, expanding)
Back to directory >> Forgings – Significance, Design, Production, Application 51 Special process for post forming
The connecting rod big end is fractured in a defined way using a splitting wedge to give an exact fit – this saves the sawing and milling operations. The individual fracture pattern is used to provide an exact fit between the two surfaces.
The breaking (cracking) of the big end is carried The pair of cracked surfaces are unique and offer out by applying pressure to a splitting wedge a high degree of fitting accuracy with relatively little effort
Back to directory >> Forgings – Significance, Design, Production, Application 52 Process combinations
The use of combinations of processes enables multi-axis forming to be carried out and thus complex geometrical forms to be manufactured
Shock absorber Gear wheel with Carrying sleeve for a Trailer axle: drop- lugs: drop-forged internal spline: warm- truck: drop-forged forged and welded; and upset forged and cold-sized; and hot-extruded; light-weight design with very high degree of multistage forming a combination of different accuracy on the flanks materials of the teeth
Back to directory >> Forgings – Significance, Design, Production, Application 53 Tooling for forging
For open-die forging, saddles with various different working surfaces are used. Dies have the "negative" form of the workpiece and can therefore only be used for specific forms Lower dies
Flat saddle
Single-impression die Multiple-impression die Multi-stage die Pointed saddle Upper die Forging Movable Die halves Die-holder opened
Rounded saddle Movable die halves Die-holder closed
Ejector Lower die Ejector Closed die Die with several closure lines Open-die forging Drop-forging: typical types of die Various forms of saddle
Back to directory >> Forgings – Significance, Design, Production, Application 54 Toolroom: manufacture of dies and other tooling
The form of a die is produced either by spark-erosion or by high-speed milling. The surface of the form is treated is various ways to improve its life (e.g. by grinding, polishing, nitriding and/or hard- chrome plating ).
Milling of CAD design of the electrode the form geometry
CNC milling of the form
Spark-erosion Finishing of of the die form the die form
Surface treatment of the die form Finished die
Diagram showing die manufacture The milling head of the high-speed milling machine rotates at up to 40,000 rpm.
Back to directory >> Forgings – Significance, Design, Production, Application 55 Heat treatment of forgings I
*Austenite formation and quenching Quenching Normalising (N) and tempering (QT)
Heat-treatment from the forging heat Soft-annealing (A)
Ac3: temperature at which the transformation of ferrite into austenite on heating is completed Ac1: temperature at which the formation of austenite on heating commences RT: room temperature Schematic representation of heat-treatment processes used for steel drop-forgings
Back to directory >> Forgings – Significance, Design, Production, Application 56 Heat treatment of forgings II
Controlled cooling from the forging heat, continuous cooling process
Controlled cooling from the forging heat (P), isothermal transformation left: diagram showing heat-treatment processes right: diagram showing the most important heat for steel drop-forgings Treatment processes for aluminium drop-forgings
Back to directory >> Forgings – Significance, Design, Production, Application 57 Surface treatment I
After forging the workpiece is descaled by shot-blasting. The shot size is between 0.8 and 2.8mm
Steel wire pellets (1,400 - 2,000 N/mm2) or steel grit (45 - 50 HRC) are used as blasting media
Back to directory >> Forgings – Significance, Design, Production, Application 58 Quality assurance for forged parts
The finished workpiece is checked dimensionally using a coordinate measurement machine. The measurements are made either on a sample basis or 100% for safety critical parts (e.g. for aircraft components).
The machine is calibrated using the yellow Diagram showing a quality control chart to workpiece (the so-called setting gauge or demonstrate process stability reference part).
Back to directory >> Forgings – Significance, Design, Production, Application 59 Non-destructive materials testing I
Magnetic-resonance testing: the raw material is Magna-Flux process: ferromagnetic particles excited by a magnetic field. Faults (resonances) align themselves preferentially along surface show up on the VDU. faults.
The lower green zigzag line on the VDU When examined under UV light, the surface indicates the fault faults become visible
Back to directory >> Forgings – Significance, Design, Production, Application 60 Non-destructive materials testing II
In non-destructive testing of materials the component remains intact and can be used further. This enables 100% testing to be carried out (e.g. for aircraft components)
Brinell hardness testing using Vickers hardness testing using a Rockwell hardness testing using a sphere and measuring the pyramid and calculating the area a cone and measurement of the diameter of indentation (10; 5; of indentation depth of indentation 2.5 and 1 mm)
Back to directory >> Forgings – Significance, Design, Production, Application 61 Non-destructive materials testing III
Ultrasonic testing
This method is used for both magnetic and non-magnetic materials.
This material fault (chevron crack) was caused by the material flow being too rapid
Back to directory >> Forgings – Significance, Design, Production, Application 62 Non-destructive materials testing IV
Ultrasonic testing VDU image
Back to directory >> Forgings – Significance, Design, Production, Application 63 Non-destructive materials testing V
Dye-penetration testing (capillary process)
A special dye, which penetrates cracks, is applied to the workpiece. After rinsing and the subsequent application of a developer, the cracks become visible. This process is used for testing non-magnetic metals.
Back to directory >> Forgings – Significance, Design, Production, Application 64 Destructive materials testing I
Destructive material testing for tensile strength and notch bar impact value is carried out on samples taken from batches of parts. The test specimens are made from finished components.
Tensile testing Load-displacement diagram of a tensile test
Back to directory >> Forgings – Significance, Design, Production, Application 65 Destructive materials testing II
The notched bar impact test is a destructive test. The test specimen is machined out of the finished component.
The notched test specimen has dimensions of 10 x 10 x 50 mm and is fractured by the pendulum
In the notched bar impact test a pendulum is swung against the test specimen. The energy required (in Joules) is proportional to the difference between the heights of the pendulum H and h. This gives a measure of the toughness of the material.
Back to directory >> Forgings – Significance, Design, Production, Application 66 Machining of forged parts
High-speed steel (HSS), tungsten carbide (TC) and ceramics are all used to make cutting tools.
Cutting speed vc (m/min) Turning Drilling
Cutting tool material f = 0,2 mm f = 0,4 mm Cutting tool material f = 0,02 x d
Hardness HB TC, uncoated 225 190 HSS, coated 25
TC, coated 290 230 TC, coated 90 190-220 ceramic 650 500
TC, uncoated 180 160 HSS, coated 18
220-250 TC, coated 250 190 TC, coated 70
ceramic 550 450
Milling cutter inserts Threads
Cutting tool material fz = 0,12 mm fz = 0,25 mm cutting tool material f = m (pitch)
190-220 TC, uncoated 300 250 HSS, coated 10
220-250 TC, coated 200 180 HSS, coated 8
Recommended cutting speeds for the machining of forgings
Back to directory >> Forgings – Significance, Design, Production, Application 67 Forged components in competition
In comparison with its cast equivalent the forged full-floating axle shown here has superior material properties and high process stability.
The costs were reduced markedly by The forged full-floating axle is cheaper, incorporating a forged part does not need subsequent hardening and tempering and has a reduced scrap rate.
Back to directory >> Forgings – Significance, Design, Production, Application 68 Diversity of forms in automotive manufacturing I
In car manufacture special properties are required, which can be achieved using hot-, warm- and cold- forging or a combination of several manufacturing steps.
Steel and aluminium chassis Engine parts are mostly made of Gear-box parts made of steel - components for car manufacture. hot-forged steel hot-forged and cold-sized
Back to directory >> Forgings – Significance, Design, Production, Application 69 Diversity of forms in automotive manufacturing II
Improved accuracy and finer detail can be achieved using combinations of hot-, warm- and cold forming processes.
Drive-train and axle parts: hot-, Gear-box shafts are often cold warm- and cold-forged extruded
Back to directory >> Forgings – Significance, Design, Production, Application 70 Diversity of forms in automotive manufacturing III
The high torques in the 2 1 2 gearboxes of today's diesel engines can only be transmitted by heavy duty forgings. The components are cold- or hot- forged or made using a combination of processes.
1 Gear-wheels
3 2 Shafts 3 Parking lot 4 4 Planet-carrier
Section through a Mercedes-Benz 7G-Tronic automatic gearbox
Back to directory >> Forgings – Significance, Design, Production, Application 71 Diversity of forms in automotive manufacturing IV
Forged parts meet high demands for fatigue strength, lightweight 5 construction and cost-effective manufacture
1 Axle pivot
2 Axle drive shaft
3 Control arm 4 Wheel carrier 1 2 3 4 5 Differential Mercedes-Benz Car, powered rear axle
Back to directory >> 72 Forgings – Significance, Design, Production, Application 72 Diversity of forms in automotive manufacturing V
Suspensions have to meet the 1 2 3 criteria of driving dynamics, ride comfort, component size, weight and modularization (platform systems).
4
1 Upper transverse control arm
2 Lower transverse control arm
3 Universal joint
4 Achszapfen
5 6 5 Left-hand wheel trunk
6 Right-hand wheel trunk Mercedes-Benz Car, non-driven front axle
Back to directory >> Forgings – Significance, Design, Production, Application 73 Diversity of forms in automotive manufacturing VI
In vehicle construction, engineers are looking for the lightest possible designs. This saves fuel and
CO2 emissions and improves comfort and driving dynamics.
This component, optimised using FEM methods, The low unsprung weight Is made of aluminium increases sprung comfort
Back to directory >> Forgings – Significance, Design, Production, Application 74 Diversity of forms in automotive manufacturing VII
Kurbelwelle Pleuel
Four cylinder motor-cycle crank drive with integrated forged gear-wheels to drive and Suspension support, forged in aluminium Control the camshaft
Back to directory >> Forgings – Significance, Design, Production, Application 75 Diversity of forms in automotive manufacturing VIII
The valve drive has to withstand extremely high accelerations and 1 temperatures. Forged components fulfil these requirements.
2
3
1 Rocker arm
2 Push-rods - cold-formed parts 5 4 3 Valve bridge
4 Camshaft
5 Inlet and outlet valves Four cylinder valve drive of a diesel engine
Back to directory >> Forgings – Significance, Design, Production, Application 76 Diversity of forms in automotive manufacturing VIII(a)
In very highly stressed areas 1 2 3 forged components improve operating safety.
1 Mount of support
2 Differential
3 Leaf spring holder
4 Gear wheels in differential
5 Propeller shaft
4 5 6 7 6 Axle drive shaft 7 Planetary gears Double floating axle with dual tyres on a truck.
Back to directory >> Forgings – Significance, Design, Production, Application 77 Diversity of forms in automotive manufacturing VIII(b)
In very highly stressed 1 areas forged components improve operating safety. 2
1 Differential
2 Leaf spring holder
3 Cardan shaft 3 4 4 Flange for cardan shaft
Double floating axle with dual tyres on a truck.
Back to directory >> Forgings – Significance, Design, Production, Application 78 Diversity of forms in automotive manufacturing IX
The individual components of a cardan shaft have to transmit high torques and be maintenance-free at the same time.
1 Flange 2 Cross pin
3 Joint fork
4 Hollow shaft 1 2 3 4 5 5 Butt-welded joint fork Cardan shaft with universal joints
Back to directory >> Forgings – Significance, Design, Production, Application 79 Diversity of forms in automotive manufacturing X
1 2 Forged components are ideal for handling the extreme mechanical and dynamic loading on heavy construction machinery.
1 Blade hinge
2 Cylinder eye
3 Scarifier tooth
4 Drive sprocket
7 6 5 4 3 5 Track guide 6 Track idlers
Bulldozer with scarifier Bulldozer 7 Track links with scarifier
Drive-sprocket segment
Back to directory >> Forgings – Significance, Design, Production, Application 80 Diversity of forms in automotive manufacturing XI
Forged components have a long life and 1 4 meet the high safety requirements of rail vehicles. 2 5 On the left a wagon bogie.
3 6 8 1 Lower pivot bearing
9 2 Brake lever joint
7 3 Axle
10 4 Side bearer 3 5 Slack adjuster 1 6 Brake block slack adjuster 2 7 Brake lever
8 Bow girder 8 9 Brake block shoe
10 10 Wheel tyre
Back to directory >> Forgings – Significance, Design, Production, Application 81 Use in pipe fittings
Valves are corrosion- and acid- 1 proof. They are used for liquid and gaseous media. 2
3 4 9 1 Handwheel
5 2 Collar
3 Neck
6 4 Gland follower 5 Bonnet
7 6 Casing 8 7 Flanges
8 Seating ring
9 Eyebolt
Left: Valve for direct welding into a pipeline Right: Valve with flanges for bolting
Back to directory >> Forgings – Significance, Design, Production, Application 82 Use in aircraft manufacture
Alongside their use in jet 1 engines, forged components are also used in highly-loaded areas such as wings, rudders, control surfaces and landing gear. 2 3
4 5
The four-engined Airbus A380 1 Low pressure compressor 2 High pressure turbine blades puts its trust in forging technology 3 Bladed disks 4 Turbine shaft 5 Turbine
Back to directory >> Forgings – Significance, Design, Production, Application 83 Use in wind turbines
1 Drive shaft 1 8
2 2 Generator
3 3 Planetary gearing
5 4 Blade adjustment. Rotor pitch
4 5 Disc brake
6 Connecting rings to steel tubular tower
7 Large roller bearing with azimuth adjustment
8 Blanks for gear-wheels, rolling and 6 plain bearings
7
View into the nacelle of a modern wind energy plant
Back to directory >> Forgings – Significance, Design, Production, Application 84 Diversity in forging technology
With the assistance of various forging and forming processes such as hot-, warm- and cold forging and their combinations, a large range and diversity of specialized components can be manufactured – with piece weights ranging from a few grams up to several tonnes in the case of open-die forging.
97 percent of forged and formed parts are made of steel, but also aluminium and titanium as well as such non-ferrous metals as copper, brass and nickel alloys.
Back to directory >> Forgings – Significance, Design, Production, Application 85 Optimization of components
FEM programs (finite element methods) offer the possibility of optimizing weight and geometry right at the design stage.
The illustration shows a steering arm with a generated FEM lattice grid
Back to directory >> Forgings – Significance, Design, Production, Application 86 Development chain I
Design, toolmaking and production are closely associated with each other to fulfil the customer's requirements.
production/ machining
specifications/ loadcases
process development part development part optimisation
A rear wheel carrier passes computer-aided through the stations above on its way from the specification through to production. Back to directory >> Forgings – Significance, Design, Production, Application 87 Development chain II
Design, toolmaking and production are closely associated with each other to fulfil the customer's requirements.
Example: the customer gives the installation space and the required properties for an aluminium front wheel swing bearing for a car. From this a first model is made and from this the forging design is developed.
Back to directory >> Forgings – Significance, Design, Production, Application 88 Development chain III
With the aid of design software (e.g. Catia, UG), the forging design is discretised according to the limiting stresses.
Back to directory >> Forgings – Significance, Design, Production, Application 89 Development chain IV
Linear-elastic FEM-simulation showing the stresses in the component.
Back to directory >> Forgings – Significance, Design, Production, Application 90 Simulation I
Simulation requires high-performance hardware for the very rapid calculation of the finite element simulation with the aid of a cluster.
Cluster of nine processor computers and one control computer
Back to directory >> Forgings – Significance, Design, Production, Application 91 Simulation II
Using the material flow simulation, designers can already see in advance whether the material distributes itself optimally during the forging process.
Visible fault caused by lack of material or an Visible lap caused by a fault in the form in the unsuitable die-form previous operation(s)
Back to directory >> Forgings – Significance, Design, Production, Application 92 Simulation III
The material flow simulation enables designers to view the forging process and possible faults in the developed tooling.
Yoke during the forging operation
Gear shaft
Back to directory >> Forgings – Significance, Design, Production, Application 93 Simulation IV
In addition, the tooling stress can be simulated in advance. The coloured gradation shows the relative or equivalent stress.
Back to directory >> Forgings – Significance, Design, Production, Application 94 Sources of illustrations and information
We would like to thank the following companies for their great help in providing illustrations and technical information: Acument Global Technologies, Inc. Lasco Umformtechnik GmbH BMW AG Mahle Brockhaus GmbH Bombardier AG Müller-Weingarten AG BPW AG Pratt & Whitney Buderus Edelstahlwerke- Presswerk Krefeld GmbH & Co. KG Schmiedetechnik GmbH Prinz Verbindungselemente GmbH Caterpillar AG Räuchle GmbH + Co. KG CDP Bharat Forge GmbH Schubert Maschinen und Anlagen GmbH Dango & Dienenthal GmbH Schuler Group Daimler AG Siepmann Persta GmbH FEMUTEC / simufact engineering GmbH SITEMA GmbH & Co. KG GKN GmbH SMS Group Hatebur AG ThyssenKrupp Gerlach GmbH Hammerwerk Fridingen GmbH ThyssenKrupp Presta AG Hirschvogel Automotive Group Volkswagen AG Kamax-Werke Zeller + Gmelin GmbH & Co. KG Karl Diederichs KG
Copyright 2011. All shown images, photos and texts are copyrighted. Partial reproduction of any contents only permitted by referencing the source. Infostelle Industrieverband Massivumformung e. V., Goldene Pforte 1, 58093 Hagen, Deutschland. Our website: www.metalform.de
Back to directory >> Forgings – Significance, Design, Production, Application 95 Imprint
Editor VAT-no.: DE 125 127 673 Infostelle Industrieverband Massivumformung e. V. Print-no. BW-411 Printed in Germany Editorial office and responsible for production: Infostelle Industrieverband Massivumformung e. V. ISBN: 978-3-923726-26-9
Manuscript The presentation is copyrighted. Partial reproduction of Ing. Horst Apholt any contents only permitted by referencing the source. The publications of the Infostelle Industrieverband Layout Massivumformung e. V. are based on the group research Peter Kanthak of the companies affiliated under the Industrieverband Freelance designer, Wickede Massivumformung e. V. organisation.
Publisher Image sources: Infostelle Industrieverband Massivumformung e. V. The following companies have supported this Goldene Pforte 1 presentation by providing source material: 58093 Hagen Germany Phone: +49 23 31 9588-30 Fax: +49 23 31 9587-30 E-mail: [email protected] Website: http://www.metalform.de
Back to directory >> Forgings – Significance, Design, Production, Application 96 Bibliography
Historical development Layout of forgings
Pischel, H.: DIN 7523: Geschichte des Massiv- und Blechumformens. Schmiedestücke aus Stahl; • Teil 2_09.86: Bearbeitungszugaben, Seitenschrägen, Krefeld: K. Dannat 1987 Kantenrundungen, Hohlkehlen, Bodendicken, Wanddicken,
Rippenbreiten und Rippenkopfradien Sonnenschein, F.H.: Die Technikgeschichte des Schmiedens. DIN 7527: Technische Kulturdenkmale 14 (1985) S. 12/17 Schmiedestücke aus Stahl; • Teil 1_10.71: Bearbeitungszugaben und zulässige Abweichungen v. Wedel, E.: für freiformgeschmiedete Scheiben Die Geschichtliche Entwicklung des Umformens in Gesenken. • Teil 2_10.71: Bearbeitungszugaben und zulässige Abweichungen Düsseldorf: VDI-Verlag 1960 für freiformgeschmiedete Lochscheiben • Teil 3_10.71: Bearbeitungszugaben und zulässige Abweichungen für nahtlos freiformgeschmiedete Ringe • Teil 4_01.72: Bearbeitungszugaben und zulässige Abweichungen Branch overview für nahtlos freiformgeschmiedete Buchsen
• Teil 5_01.72: Bearbeitungszugaben und zulässige Abweichungen Vieregge, K.: für freiformgeschmiedete, gerollte und geschweißte Ringe Gesenkschmieden in Deutschland – im Zeichen des Wandels. • Teil 6_02.75: Bearbeitungszugaben und zulässige Abweichungen Umformtechnik 27 (1993) 3 für freiformgeschmiedete Stäbe
Voigtländer, O.: Perspektiven der Massivumformung in den 90er Jahren. Werkstatt und Betrieb 121 (1988) 7. S. 561/567
Back to directory >> Forgings – Significance, Design, Production, Application 97 Bibliography
DIN EN 10 243: Production of forgings Gesenkschmiedeteile aus Stahl • Teil 1_12.95: Warm hergestellt in Hämmern und Pressen Dahme, M. und Hirschvogel, M: Maßtoleranzen Deutsche Fassung EN10 243-2: 1995 Möglichkeiten und Grenzen der Kalt-, Halbwarm- und Warmumformung. Werkstatt u. Betrieb 124 (1991), S. 865/868 DIN 17 864: 02.93: Schmiedestücke aus Titan und Titan-Knetlegierung Düser, R.: (Freiform- und Gesenkschmiedestücke) Gesenkwalzen – Ein Maximum an Präzision bei einem Minimum an Material- und Energieeinsatz. Umformtechnik 26 (1992) 1, S. 33/40
DIN Normenheft 7: Anwendung der Normen über Form- und Lagetoleranzen in der Praxis. 4. Auflage Berlin und Köln; Beuth-Verlag 1987
Breuer, H.-W.: Gestaltung beanspruchungs- und fertigungsgerechter Schmiedeteile. Konstruktion 43 (1991) S.285/291
Dahme, M. u.a.: Gemeinschaftliche CAD/CAM- Entwicklungen: Basis für Simultaneous Engineering. Schmiede-Journal (1995) September S. 17/18
Back to directory >> Forgings – Significance, Design, Production, Application 98 Bibliography
Elsinghorst, < Groene, S.: Lange, K. (Hrsg.): Axiales Gesenkwalzen – ein Verfahren der Warmformgebung zur Umformtechnik Bd. 2, Massivumformung. Berlin, Heidelberg, Herstellung von rotationssymetrischen Schmiedeteilen für die New York: Springer-Verlag 1988 Kraftfahrzeugindustrie, Thyssen Techn. Ber. 18 (1986) 2, S. 353/360 Metals Handbook: Vol. 14, Forming and Forging 9. Ed. Metals Park Jung, H.: (Ohio): American Soc. for Metals 1988 Erhöhung der Fertigungsgenauigkeit nach dem Schmiedeprozess durch Warm- und Kaltprägen, VDI-Z 133 (1991) 11, S. 49/56 Schiller, w.: Wirtschaftliches Fertigen durch gratloses Schmieden – Kostenvorteile, König, W. und Klocke, F.: Industrie-Anzeiger 110 (1988) 5, S. 34/36 Fertigungsverfahren Bd. 4 Massivumformung Düsseldorf VDI-Verlag 1995 Schuler GmbH (Hrsg.): Handbuch der Umformtechnik. Berlin, Heidelberg: König, W. und Klocke, F.: Springer-Verlag 1996 Fertigungsverfahren 4 - Umformen Springer-Verlag 2006 Vogt, H.–J.: Gesenkschmieden und Schweißen. Der Konstrukteur 10 (1979) 11, Körner. E. u.a.: S. 41/51 Möglichkeiten des HW-Fließpressens in Kombination mit dem Kaltfließpressen. Symposium „ Neuere Entwicklungen in der Material properties Massivumformung“ 28./29.05.91 Fellbach. DIN-Taschenbuch 218: Wärmebehandlung metallischer Werkstoffe, Normen. 2. Auflage Berlin und Köln: Beuth-Verlag 1989 Back to directory >> Forgings – Significance, Design, Production, Application 99 Bibliography DIN-Taschenbuch 401: Herbertz, R.: Stahl und Eisen; Gütenormen 1, Allgemeine Normen, Berlin, Wien, Qualitätssicherung für den Schmiedeprozess. In: Ber. Aus Forsch. Zürich: Beuth-Verlag 1993 und Entwicklung, Hagen: Industrieverband Deutscher Schmieden e.V. (Hrsg.) 1992 Stahleisen-Liste (Hrsg. VDEh): 9. Auflage Düsseldorf: Verlag Stahleisen 1994 Mäscher, G. und Schmidt, J.: Schmiedeteile aus AFP-Stählen. Erfahrungen bei der Anwendung Stahlschlüssel: in Kraftfahrzeugen. VDI-Z 133 (1991) 4, S. 124/131 18. Auflage Düsseldorf: Verlag Stahleisen 1998 Masing, W. (Hrsg.): Bräuer, G.: Handbuch Qualitätsmanagement. 3. Auflage Die Qualität von Schmiedeteilen sichern. VDI-Z 132 (1990) München: Carl Hanser Verlag 1994 4, S. 125/128 Schüle, W. und Huchtemann, B: Broszeit, E. und Steindorf, H.: Entwicklungsstand der ausscheidungshärtenden Mechanische Oberflächenbehandlung, Festwalzen, Kugelstrahlen, ferritischperlitischen (AFP-)Stähle mit Vandium-Zusatz für eine Sonderverfahren. geregelte Abkühlung von der Warmformgebungs-Temperatur. Oberursel: DGM Informationsgesellschaft 1989 VDI-Ber. Nr. 774, Düsseldorf: VDI-Verlag 1989 Grubisic, V. und Sonsino C.M.: Spitzer, H.: Einflußgrößen der Betriebsfestigkeit geschmiedeter Bauteile. Maschinenbaustähle-Entwicklungstendenzen und Normung. VDI-Z 134 (1992) 11, S. 105/112 Umformtechnik 27 (1993) 1, S. 39/45 Harms, w.: Sonsino, C.M. und Kaufmann: Qualitätssicherung für den Schmiedebetrieb umfasst die ganze Einflüsse auf die Schwingfestigkeit von Gesenkschmiedeteilen. Fertigung vom Entwurf bis zum Versand. Maschinenmarkt 97 VDI-Z 133 (1991) 4, S. 131/143 (1991) 25 S. 32/35 Back to directory >> Forgings – Significance, Design, Production, Application 100 Bibliography Winkler, H.: Breuer, H.-W.: Wirtschaftliches Spanen von Schmiedeteilen in der Praxis. Weiterentwicklung von Achsschenkel für Nutzfahrzeuge. Hagen: Informationsstelle Schmiedestück Verwendung Schmiede-Journal (1995) März, S. 18/19 1988 Jung, H.: N.N.: Gesenkschmiedestücke für Bergbaumaschinen. Moderne Methoden der Qualitätssicherung in der Bergbau 32 (1981) 6, S. 312/318 Umformtechnik. Umformtechnik 24 (1991) 4, S.69/76 Jung, H.: Gesenkschmiedestücke für Getriebe und Kupplungen. N.N.: VDI-Z 123 (1981) 11, S. 584/588 Praktische Wärmebehandlung. 2. Auflage Hagen: Industrieverband Deutscher Schmieden e.V. (Hrsg.) 1997 Schmieder, F. und Kettner, P.: Fertigung von Getriebe-Hohlwellen durch Massivumformung. Examples of application of forgings Konstruktion 48 (1996) S. 402/406 Adolf, W.W.: Westerkamper, Ch. und Weißmann, G: Entwicklungen bei Getriebewellen für Fahrzeuge. Präzisionsumformung – eine Schlüsseltechnologie für die Schmiede-Journal (1995) März, S. 15/17 Antriebstechnik. VDI-Z 9 (1997) S. 72/74 Adolf, W.W.: N.N.: Kurbelwellen für Straßenfahrzeug-Motoren. Schmiedestücke im Maschinen- und Anlagebau. Schmiede-Journal (1994) März, S. 13/16 Hagen: Informationsstelle Schmiedestück Verwendung 1981 Back to directory >> Forgings – Significance, Design, Production, Application 101 Annex Manufactures of hot and cold forgings The actual delivery facilities of the member companies within the Industrieverband Massivumformung e. V. you can find in our six different manufacturer lists (Drop-forged parts, upset forged parts, hot extruded parts, cold extruded parts, open-die forged parts, rolled rings). The manufacturer lists can be downloaded free of charge (pdf data) on the internet: www.metalform.de Back to directory >> Forgings – Significance, Design, Production, Application 102