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11 Industrialization of Cross Wedge Rolling Eric FREMEAUX 1, Catalina GUTIERREZ 2, Laurent LANGLOIS 2, Philippe MANGIN 2, Rgis BIGOT 2, Pierre KRUMPIPE 3, Valery SHCHUKIN 4 With the technical and scientific support of: -IWU Chemnitz, Dr-Ing Hab. Bernd LORENZ 1 Ateliers des Janves, Avenue des marguerittes, 08120 Bogny-sur-Meuse, France 2 ENSAM, 4 rue Augustin Fresnel, 57070 Metz, France 3 CETIM, 7 rue de la Presse, 50802 Saint-Etienne cedex 1, France 4 Physical Technical Institute, 10 Kuprevich Street, 220141 Linsk, Belarus

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22 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

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33 Introduction 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 is a metal forming process in which a cylindrical billet is plastically deformed into another axisymmetrical shape by the action of wedge segments. CWR Facilities at Ateliers Des Janves

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44 Cross wedge rolling Double-diameter reduction. CWR tool with 2 wedges. Rolled parts can be of simple diameter reduction or of several reductions. Five-diameter reductions CWR tool with 5 wedges Simple diameter reduction. CWR tool with 1 wedge. [PATER 2010]

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55 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. 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 Cross Wedge Rolling Forging Rolling

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66 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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77 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

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88 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

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99 Diagram of a wedge configuration [PATER 2003] CWR Tool Design Parameters Forming angle Spreading angle Knifing/ Ramp angle Cp Knifing zone Cg Guiding zone Ce Forming zone Cc Sizing zone Yp Wedge height Le Spacing of the wedge Cp Cg Ce Cc 02 01 02 03 Yp Le x x y y z z Profil 01 Profil 02 Profil 03 03 01 Geometrical parameters of die configuration Parameters of die configuration - Identification of the tool design parameter It is based on the parametric definition of the desired rolled part and on the parametric definition of the tool.

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10 Cross wedge rolling tool design procedure COLT Design rules Integrate the state of art and expertise as far as possible 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; [Fu and Dean 1992] Risk of central porosity [Fu and Dean 1992] Necking Stability Index: -Associated with design parameters or function of design parameters -Associated with each defect

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11 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

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12 Cross wedge rolling tool design procedure COLT 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. 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. Conclusions Benefits

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13 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

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14 Tool Life in CWR are limited by geometrical defects of the rolled part -The forged part doesnt meet its requirements -Defects -Dimension -The shape of the rolled part cannot be hot forged Common defects on CWR products [Li and Lovell 2002] CWR Tool Life Spiral groove and striation Center cracking

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15 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 CWR Tool Life

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16 Synchronism of two-roll tool during rolling High speed camera Schema installation recorded image by the high speed camera Synchronism of the grooves passing through a fixed frame was studied. An analysis of the average angular velocity was calculated by measuring the time between two grooves through the fixed frame. CWR Tool Life

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17 Evolution of tool wear Non-contact 3D measurement methods Computer stereo vision -Relative position of the different parts of the tool -Evolution of the geometry due to wear CWR Tool Life

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18 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 CWR Tool Life

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19 Industrial Academic Partnership ENSAM CETIM -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 Ateliers des Janves -Investment -Industrial implementation of the CWR -Know-how and experience Skill - Knowledge management - Process thermo mechanical simulation - Measurement and control of manufacturing process Industrial requirement Know-how Industrial facilities 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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20 Thank you for your attention