Flexible Rolling of Tailor Rolled Blanks - innovative light weight design in steel -

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1 Flexible Rolling of Tailor Rolled Blanks - innovative light weight design in steel - Dr.-Ing. Michael Rehse Muhr und Bender KG

2 Tailor Rolled Blanks - a light weight design opportunity - Flexible Rolling is a continuous rolling process with periodically varying thickness. Side Member Reinforcement Rocker Cross Member Rear Axle Heel Cross Member Side Member Rear Seat Cross Member Mubea developed the complete process chain for a steel component made of TRB The adoption of TRB in the automotive industry offers great potential for the optimization of weight, function, cost and complexity. Verification of competitiveness: supply orders with Audi, BMW, DCX, GM & Skoda ( 31 parts) Ongoing launches in Europe and North America Serial production of Tailor Rolled Tubes with an annual capacity of 1 million tubes Front Seat Cross Member Cockpit Cross Member Connection Member Application studies for multiple car and truck bodies Verification of volume production capability: 16,500 to / 5.75 million blanks up to now Bumper Reinforcement Safety Belt Side Member During the past 5 years, lightweight construction potential, feasibility, competitiveness and volume production capability of Flexible Rolling have been verified.

3 Mubea Group Product Range Engine Components Suspension Components Valve Springs Hose Clamps Belt Tensioner systems Camshafts Body & Interior Suspension Coil Springs Head Rests Stabilizer Bars Transmission Components Tailor Rolled Blanks System Components Suspension Transmission Disc Springs Drive and Transmission Shafts Mubea as a lightweight design specialist supplies automotive OEM s worldwide with steel based products. Using Mubea lightweight innovations, a weight reduction of 20 kg per vehicle can be achieved. Tailor Rolled Tubes

4 Mubea Group Worldwide presence Attendorn, Germany Warnstedt, Germany Florence, KY, USA Zebrák, Czech Republic Taicang, China Taubaté, Brazil Production plant Development Center Over 4, production sites enable us to serve the customers worldwide.

5 Mubea Group Sales development Target 2010: 1 billion Sales in M Mubea strives for a continuous growth in the coming years.

6 Mubea Cold Rolling Mill Many years of experience in the cold rolling area Annual production of t / year Core competence in the following materials - Spring steels - Mild and higher-tensile steels Expansion of the cold rolling mill in two steps Flexible rolling facility I: Flexible rolling facility II: Materials: - Deep-draw grades - Micro-alloyed steels - Higher-tensile steels t / year t / year Mubea has a long experience in cold rolling.

7 Principle of Flexible Rolling Defined sheet metal thickness contours Uniform thickness transition areas High efficiency as strip rolling process Can be applied to all rollable metals Mubea is convinced that lasting success can only be achieved in partnerships.

8 TRB Properties Feasible Profile Shapes Strip Banddicke thickness in mm Strip Banddicke thickness in mm in mm 1,6 1,4 1,2 1,0 0,8 0,6 0,4 0,2 0, gewalzte Bandkontur Sollprofil strip Meßweg length in in mm 0.5 gewalzte Bandkontur Sollprofil strip Meßweg length in in mm Varying sheet metal thickness with smooth transitions 50% max. thickness reduction Slope between 1/3000 up to 1/100 Thickness tolerances 50µm Optimized sheet thickness dependent upon the load The cost of the component does not depend on number of thickness steps Reduction of sheet and component weight Flexible Rolling allows to produce components with almost all thinkable thickness changes.

9 TRB Properties Strip thickness in mm Strip Banddicke thickness in mm in mm 1,8 1,6 1,4 1,2 1,0 0,8 0,6 0,4 0,2 0, gewalzte Bandkontur Sollprofil strip length in mm gewalztes Bandprofil Sollprofil strip Meßweg length in mm in mm Feasible Profile Shapes Varying sheet metal thickness with smooth transitions 50% max. thickness reduction Slope between 1/3000 up to 1/100 Thickness tolerances 50µm Optimized sheet thickness dependent upon the load The cost of the component does not depend on number of thickness steps Reduction of sheet and component weight Flexible Rolling allows to produce components with almost all thinkable thickness changes.

10 Principle and Status of TRB Flexible Rolling coil to coil hood-type annealing furnace Process chain of Tailor Rolled Blanks strip galvanizing profile levelling and cutting profile forming into a part part with different Sheet thicknesses Mubea has developed the complete process chain for a steel component made of Flexibly Rolled Parts.

11 Cold Rolling Plant in Attendorn Start of construction work: Ma `03 Completion of building: Jan `04 Start of equipment installation: Feb `04 First Coil: Aug `04 Capacity: t/year

12 Prinzip und Status von TRB FlexWalze 1

13 Principle and Status of TRB Process chain of Tailor Rolled Parts Flexible Rolling coil to coil hood-type annealing furnace strip galvanizing Coil Component manufacturing part with different Sheet thicknesses Mubea developed the complete process chain for a steel component made of Flexible Rolled Blanks.

14 Production Technology TRB Pressed Parts Mubea Press Shop Application Example: Steering Link Mechanical press, Press force: tonnes Max. length pressed parts: 1450mm Max. length developed blanks: 2500mm Fully automated part / developed blank production from coil Fully automated blank orientation (lengthwise or across the rolling direction), independent of die In-house processing of Tailor Rolled Blanks Principle and Status of TRB Wall Thickness in mm 4,00 3,00 2,00 1,00 New Mubea Press Shop 0, Platinenlänge in mm Blank Length in mm Process Chain Decoiling Cutting Transport + Forming Part Rotation Short processing time: raw material coil to the finished, flexibly rolled component in one plant. Cost reduction due to omittance of storing and one production step (stackling of blanks).

15 Properties of TRB Forming behaviour Tension distribution: Weld seam vs. continuous transition TWB TRB Analysis of the deep drawing performance Continuous transition Harmonic tension distribution throughout the thickness transition area Homogeneous surface No disturbed fibre pattern No notch effect No detrimental effects on microstructure caused by welding Can be modelled for simulation Source: RWTH Aachen, Institut für Bildsame Formgebung Forming properties are comparable to conventionally rolled metal The material and forming properties of Tailor Rolled Blanks are comparable to conventionally rolled metal.

16 Features of TRB Process flexibility sheet metal thickness in mm 1,60 1,20 0,80 0,40 0,00 contour changes length in mm The flexible rolling process enables non tool-related production Simple software programming allows contour changes from one coil to the other Cost efficient manufacturing of derivates or product variants Without set-up costs No additional body shop costs Easy contour optimization due to the flexibility of the process.

17 Features of TRB Functional improvement Cross member Side member 1,85 1,35 1,35 1,20 1,00 1,35 1,85 1,00 1,50 1,00 sheet metal thickness in mm 2,00 1,50 1,00 0, length in mm Part design requires increased thickness Optimized distribution of stiffness in outer areas by matching of sheet thickness (NVH) Front crash demands local up-gauging at load exposed front and below x-member Improvement of crash performance With local sheet metal thickness adaptations to the load Tailor Rolled Blanks provide best performance at minimum weight. sheet metal thickness in mm 1,60 1,20 0,80 0, length in mm

18 Features of TRB Integration of components sheet metal thickness in mm 2,50 2,00 1,50 1,00 0,50 conventional design TRB design length in mm Conventional design: 1 component 4 reinforcements 5 parts TRB design: 1 part Opportunities: production costs tool costs / investments assembly process logistic costs floor space required Potential savings up to 1 US$/unit exclusive of weight-increasing Reduction of assembly groups by Tailor Rolled Blanks.

19 Application Examples Structure & chassis parts tunnel reinforcement roof bow cross member Load exposed parts with sufficient thickness for local reductions Sub-assemblies with reinforcements strut tube Weight reduction of 20% and above Straight parts with high connection member rear side member material utilization from blank to part (below 40%) front side member seat cross member rocker panel Integration of parts to reduce complexity The technology offers high potentials for different components in the structure and chassis areas. Application criteria for optimum TRB applications have been identified.

20 TRB Series Applications Rear cross member Increased torsional stiffness Weight reduction of 1,2 kg vs. conventional part HSLA 300 / 350 TRB Z100 flexible rolled 1,9 > 1,05 > 1,9 mm 2 1,05 1,93 Strip Banddicke thickness in mm in mm 1,8 1,6 1,4 1,2 1 1,93 0, Strip length in mm Platinenlänge in mm Producing structure parts for the DC E-class and the BMW 5-series, we verified volume production capacity.

21 TRT Series Applications Cockpit cross member 30% weight reduction Narrowest part tolerances Cost-effective light weight construction HSLA420 TRB flexible rolled 1.0 > 1.6 > 1.8 > 1.6 > 1.0 > 1.4 > 1.0 Strip Wandstärke thickness in in mm mm 2,00 1,80 1,60 1,40 1,20 1,00 0,80 0,60 0,40 0,20 0, Tube Rohrlänge length in mm Considering the technology advantages of TRB during the part development process results in maximal weight reduction and low costs.

22 Tailor Rolled Products Tube Production Line Layout tube production line Discontinuous tube production High number of profile shapes by means of flexible forming techniques Connection by laser beam welding Integration of further process steps like bending and forming Profile shapes Tube with a constant outer diameter and invisible thickness transition run Tube with constant inner diameter and visible thickness transition run Tube with variable diameters and varying thicknesses Mubea put the first production line for Tailor Rolled Tubes in stream.

23 Development of Tailor Rolled Tubes (TRT) Tailor Rolled Tube with variable diameters Diameter variation: 52% Thickness variation: 43% Weight reduction: 33% Different diameters along the whole tube Different thicknesses over the whole length of the tube Maximum weight savings High degree of design flexibility Cost efficient manufacturing of complex tube Diameter variation: 31% Thickness variation: 50% Weight reduction: 35% geometries (compared to hydro forming) Manufacturing tubes with variable diameters and sheet metal thicknesses features maximum flexibility in weight optimization and design.

24 Hot fromed TRB Combination of Hot Forming and Flexible Rolling Coil Coil rolling levelling, profile cut Oven Press with cooling The combination of matched sheet metal thickness and extremely high material strengths allows a maximal weight reduction.

25 Hot fromed TRB PM49 B-Pillar 24% weight reduction Improved crash performance as a result of integration of components and adaptation of thickness BTR 165 TRB flexible rolled 1.0 > 1.9 > 1.6 > 1.3 sheet metal thickness in mm length in mm die hardened Rp0.2 [N/mm²] Rm [N/mm²] A5 [%] min. 950 min min. 6 Weight optimized B-pillar design through load adapted thicknesses.

26 Summary Flexible Rolling is designed as a continuous rolling process for metal sheets with periodically varying thickness. Mubea developed the complete process chain for a steel component made of Flexible Rolled Blanks. The adoption of Tailor Rolled Blanks in the automotive industry offers great potential for the optimization of weight, function, cost and complexity. The material and forming properties of Tailor Rolled Blanks are comparable to conventionally rolled metal. All conventional process steps for the production of metal parts are applicable for Tailor Rolled Blanks. The technology offers high potential for different components in the structure and chassis area. Mubea has put the first production line for Tailor Rolled Tubes in stream. World-wide, Mubea is leading in the production of Tailor Rolled Products.

27 THANK YOU VERY MUCH FOR YOUR ATTENTION!!!!