Manufacturing Processes
Bulk Deforming (부피 성형가공)
Bulk Deforming
© www.afdex.com
Manufacturing
Processes
© 2012 Su-Jin Kim GNU
Su-Jin Kim
Mechanical Engineering
Gyeongsiang National University
Korea
Contents
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Forging
Rolling
Extrusion
Drawing
Tube deforming
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
Forging (단조)
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Forging is the shaping of metal using plastic
deformation takes place by compressive forces.
It can be carried out at room (cold forging 냉간단조) or
above recrystallization temperature (hot forging
열간단조).
Stronger than an equivalent cast or machined part.
Expensive die, press and furnace facilities.
Post machining is required. Ductile metal.
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
Open-die forging(자유단조)
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Open-die forging is usually done by hammering a part
between two flat faces.
It is used to make parts that are too big to be formed in
a closed die or in cases where only a few parts are to be
made without die.
©steelindustriesinc.com
Bulk Deforming
Manufacturing
Processes
http://www.youtube.com/watch?v=tLRkOupbARM&p=9B6D9EAE75875D9D
© 2012 Su-Jin Kim GNU
SME 1min
Open-die forging
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Berreling is caused by friction force at die-workpiece
interface.
Friction and the aspect ratio effects forging force.
Forging force: F≈σyA(1+μr/h)
F
h
Die
r
Barreling
μ, friction
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
Impression-die forging (형단조)
• Workpiece acquires the shape of the die cavity while
deformed between the closing dies.
• Forging force : F  k p y A
kp: pressure-multiplying factors (3~12)
• also called Closed-die forging (패쇠단조)
Die
Parting line
Flash Land
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
Forging Die (단조 금형)
• Require multi-stage forging to ensure proper distribution
of the material in the die cavities.
• Parting line is designed based on shape, metal flow, force.
• Flash clearance is 3% of max thickness.
• Draft angle > 5~7° for steel.
• Corner fillets radii for smooth flow. Die
Fillet
• low and wide Ribs
Parting line Flash
• Metal fiber flow lines.
Flow lines
Rib
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
Forging die & flash
• Source geometry and die and flash size.
Forging die
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
O
X flash
Impression-die hot forging
1STAGE
2STAGE
3STAGE
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
http://ma.gnu.ac.kr/vod/Forming/Hot_Forging.wmv Hot forging
Bucket
Tooth
©gsf.co.kr
Continuous Cross Section
• Rolling
• Extrusion
• Drawing
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
Rolling (압연)
• Metal stock is passed through a pair of rolls to reduce
thickness.
• Hot rolling(열간압연) > recrystallization temperature > Cold
rolling(냉간압연)
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(Roll bending)
(Roll forming)
Flat rolling
Ring rolling
Structural shape rolling
Bulk Deforming
Manufacturing
Processes
http://www.youtube.com/watch?v=6xnKmt_gsLs&p=9B6D9EAE75875D9D
© 2012 Su-Jin Kim GNU
Rolling 3m
Flat Rolling (평판 압연)
• Rectangular cross-section (sheet, plate)
• Force: F ≈ σylw
• Draft: t0 - tf < μ2R
w
t0
F
tf
l
R
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
Ex) Flat Rolling Force Power
Ductile plate (width: 0.1 m, thickness: 10 mm, strength: 400
MPa) is rolled by flat rollers (radius: 0.1 m). The friction
coefficient of roller and plate is 0.2 and production rate is 1
m/s. How many times should the plate pass the roller to get
5 mm thickness plate? Please predict approximate rolling
Force (kN) and Power (kW).
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
Ring rolling (링압연)
• Driven and idle roll presses the ring to decrease thickness
and increase diameter.
Driven roll
Idler roll
Side roll
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
http://www.youtube.com/watch?v=GDyWyDP3cvs Ring rolling
Structural shape rolling (형압연)
• Structural shape rolling uses profile rolling
techniques where the workpiece is passed
through a series of rollers that match the
workpieces' cross-section.
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
Thread rolling (나사 전조)
• Threads are formed by pressing a blank with the
former(shaped die).
Thread Rolling
Die
Blank
www.horstengineering.com
Bulk Deforming
Manufacturing
Processes
Bolt:
http://www.youtube.com/watch?v=7ORomNNCSUQ&p=9B6D9EAE75875D9D Bolt Nut 5m
© 2012 Su-Jin Kim GNU
Extrusion (압출)
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A round billet is placed in a chamber and forced through a
die opening by a ram.
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It creates complex fixed cross-sectionals.
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Pressure: p≈σy(0.8+1.4ln(Ao/Af))
Container
Die
Ram Billet
F
Ao
Af
Hot extrusion profiles of steel
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
http://www.youtube.com/watch?v=7qiDJ5U4uRc Extrusion 1m
Drawing (인발)
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Reduce the cross-section of a road, wire or tube by pulling
it through a drawing die
Lubrication is essential for good surface finish and long
die life
Die
A0
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
Af
F
Spring forming machine
• Spring forming machine controlled by mechanical cam
and link.
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
http://ma.gnu.ac.kr/vod/Forming/Spring_Former.wmv Spring former
Rotary Swaging
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Split dies separate and close to reduce the diameter and
produce a taper of tube.
Die
Tube
Mandrel
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
Tube (Pipe) Bending
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Straight tube is bended into the desired form.
Be careful to buckle inward during bending.
Former
Tube bending
Clamp
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
http://ma.gnu.ac.kr/vod/forming/Pipe_Bending.wmv
Tube Hydroforming
• Hydraulic pump injects high pressure fluid inside a
hollow tube to expand until it matches a negative mold.
• Strong and light structures for vehicles
Dies
Hydraulic
pressure
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
Tube
Seals
SME: http://www.youtube.com/watch?v=nylIvins3XE
Com: http://www.youtube.com/watch?v=i2ac6A3FJ6E&hl=ko
Characteristics (특징)
Advantages
Disadvantages
Fast & mass production
Expensive equipment and dies
Improved strength
Ductile materials
Surface finish and tolerance
are better than casting
Shape is limited by strain/flow
Size is limited by force/equipment
Strength is improved because of work hardening, grain refining, fevering,
defect closure
Surface finish and tolerance are better than casting, worse than machining
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
Economics (경제성)
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
4 5 6 7 8 9
Cost per pieces
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Tool and die cost middle or high but spread over the
number of parts
For large quantities forging is more economical than sand
casting
Investment
casting
Forging
Sand
casting
1 2 3
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100
Die
casting
101
102 103 104
Number of pieces
105
106
Bulk Deforming Simulation
• http://www.afdex.com
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU
References
• http://www.afdex.com
• http://www.kforge.or.kr
• http://www.posco.co.kr
Bulk Deforming
Manufacturing Processes
© 2012 Su-Jin Kim GNU