Industrialization of Cross Wedge Rolling
Eric FREMEAUX1, Catalina GUTIERREZ2, Laurent LANGLOIS2,
Philippe MANGIN2, Régis BIGOT2, Pierre KRUMPIPE3, Valery SHCHUKIN4
1Ateliers
des Janves, Avenue des marguerittes, 08120 Bogny-sur-Meuse, France
4 rue Augustin Fresnel, 57070 Metz, France
3CETIM, 7 rue de la Presse, 50802 Saint-Etienne cedex 1, France
4Physical – Technical Institute, 10 Kuprevich Street, 220141 Linsk, Belarus
2ENSAM,
With the technical and scientific support of:
- IWU Chemnitz, Dr-Ing Hab. Bernd LORENZ
11
Summary
1.
Introduction
• CWR principle
• Advantages and disadvantages
• Objectives
2.
CWR tool design
• Design rules
• Application
3.
To increase CWR Tool Life
• Identification of the limiting phenomenon
• Experimental – numerical investigation
4.
Conclusion and future evolution
22
Introduction
CWR is a metal forming process in which a cylindrical
billet is plastically deformed into another
axisymmetrical shape by the action of wedge segments.
The two main configurations industrially
developed are: (A) flat type and (B) two roll type
[Li, et al., 2008].
Flat wedge type
Two-roll type
CWR Facilities
at Ateliers Des Janves
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Cross wedge rolling
Rolled parts can be of simple diameter reduction or of several reductions.
Simple diameter reduction.
CWR tool with 1 wedge.
[PATER 2010]
Double-diameter reduction.
CWR tool with 2 wedges.
Five-diameter reductions
CWR tool with 5 wedges
44
Advantages and disadvantages
Benefits [Li and Lovell 2002] [Li and Lovell 2008]
• Material and energy saving process with lower environmental impact.
• Higher productivity (cycle time up to 5 – 10 sec).
• High accuracy and maximum proximity to required dimensions of finished products.
Cross Wedge Rolling
Forging Rolling
Difficulties [Weronski and Pater 1992]:
• Process with a high degree of technological complexity
• Number of parameters affecting the stability of the process.
• Relationship between the parameters that must be correctly chosen in order to
avoid failures.
• Slight variations in basic parameters can have a high impact on the rolled part.
• CWR tool design has been based on the experience and intuition of designers. No
decision-making tools publicly available to the date.
• Tool manufacturing and development cost
55
Introduction
Application
- Preform: Hot forging of connecting rod
- Robotized forging workcell
- Hammer
- Productivity
- 150% higher / Classical line
- Quality: number of scrap parts / 2
- Material saving (5%-15%)
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Objectives
In order to increase the performances of CWR
1. To reduce the developing time and cost of new CWR tool
•
•
To reduce the experimental part of the tool development
To automate as far as possible the tool design methodology
2. To improve the life of the CWR tools
•
•
To increase the life of CWR (Number of parts manufactured per tool)
To stabilize the tool behavior
• To reduce the dispersion of the tool life
• To reduce the number of defect types limiting the tool life
77
Summary
1.
Introduction
• CWR principle
• Advantages and disadvantages
• Objectives
2. CWR tool design
• Design rules
• Application
3.
To increase CWR Tool Life
• Identification of the limiting phenomenon
• Experimental – numerical investigation
4.
Conclusion and future evolution
88
CWR Tool Design
• It is based on the parametric definition of the desired rolled
part and on the parametric definition of the tool.
- Identification of the tool design parameter
Parameters
𝛼
𝛽
ϒ
Cp
Cg
Ce
Cc
Forming angle
Spreading angle
Knifing/ Ramp angle
Knifing zone
Guiding zone
Forming zone
Sizing zone
Yp Wedge height
Le Spacing of the wedge
Diagram of a wedge configuration [PATER
2003]
Parameters of die
configuration
Cc
α 03
Profil 03
Le
β 03
Ce
Profil 02
Yp
β 01
Profil 01
β 02
x
ϒ
Cp
x
z
y
Cg
α 02
α 01
y
z
Geometrical parameters of die configuration
99
Cross wedge rolling tool design procedure COLT
• Integrate the state of art and expertise as far as possible
Design rules
o Design rules found in literature and identified during
experimental work.
o Design rules are associated with stability index
o Flexible tool by allowing updating of the already existing rules
and the implementation of new design rules;
Stability Index:
- Associated with design parameters
or function of design parameters
- Associated with each defect
10
Cross wedge rolling tool design procedure COLT
Output:
• Geometrical parameters of the CWR tool
• Coordinates of remarkable points for
o flat type and/or
o two-roll type
• Stability Indexes (potential defects)
.txt file with
coordinates of
remarkable points
11
Cross wedge rolling tool design procedure COLT
Conclusions
A decision supporting methodology for the designing of the tool in CWR is being developed.
• Solution provided by COLT is not expected to be immediately efficient but as close as
possible to a performant solution.
• Synthesis of literature and experimental rules.
• The designing rules allow the selection of basic parameters.
• An stability index is introduced to take into account the inconsistencies in literature.
Benefits
The advantages of the methodology are:
• Non-expert user will have a first guided approach to the CWR process.
• Identification of the potential defects with the associated basic parameters.
• Flexibility of the methodology by the updating of exiting rules and implementation of new ones.
12
Summary
1.
Introduction
• CWR principle
• Advantages and disadvantages
• Objectives
2.
CWR tool design
• Design rules
• Application
3. To increase CWR Tool Life
• Identification of the limiting phenomenon
• Experimental – numerical investigation
4.
Conclusion and future evolution
13
CWR Tool Life
Tool Life in CWR are limited by geometrical defects of the rolled part
- The forged part doesn’t meet its requirements
- Defects
- Dimension
Spiral groove and striation
Center cracking
Common defects on CWR products [Li and Lovell 2002]
-
The shape of the rolled part cannot be hot forged
14
CWR Tool Life
Methodology
• Identification of the statistical correlations between:
• Geometrical, kinematical, thermo mechanical parameters
and
• Limiting phenomenon
• Initial value and evolution of the parameters along the tool life
•
Relative initial position of the different parts constituting the tools
•
Differential Kinematics of the tools
•
Evolution of the shape of the tool due to wear
•
Distribution of the temperature at the surface of the tool
•
…
15
CWR Tool Life
Synchronism of two-roll tool during rolling
High
speed
camera
Synchronism of the grooves
passing through a fixed
frame was studied.
Schema installation
recorded image by the high
speed camera
An analysis of the average angular velocity was calculated by measuring the time between
two grooves through the fixed frame.
16
CWR Tool Life
Evolution of tool wear
Non-contact 3D measurement methods
-
Relative position of the different parts of the tool
Evolution of the geometry due to wear
Computer stereo vision
17
CWR Tool Life
Conclusions and perspectives
1- Experimental and statistical identification of the correlation between
tool and process parameters and the phenomenon limiting tool life
2- Experimental and modelling-simulation investigation
Statistical relation  Qualitative – Quantitative Physical relation
3- To design and to implement solutions in order to increase and better control
the life cycle of the CWR tool.
4- Integration of the result as knowledge withn the tool design methodology
- New design rules
- New process parameters
18
Industrial – Academic Partnership
ENSAM – CETIM
Ateliers des Janves
-
-
State of the art
Identification of the key parameters
Initial version of the design methodology
(Formalization of the know-how)
Scientific et technological support of PTI and IWU
Financial support of Region Lorraine
Investment
Industrial implementation of the CWR
Know-how and experience
Industrial requirement
Know-how
Industrial facilities
Skill
- Knowledge management
- Process thermo mechanical simulation
- Measurement and control of manufacturing
process
Fruitfull collaboration
- Increase of the skill based on scientific and technological approach
- Integration of the skill as computer aid tool for the industrialization of the process
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Thank you
for your attention
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