The Mass-Reduction Potential of Tailored Steel Products for Automobiles

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1 The Mass-Reduction Potential of Tailored Steel Products for Automobiles Peter R. Mould Tailored Steel Product Alliance (TSPA)

2 OUTLINE Definition of tailored steel products Description of TSPA Automotive Requirements Purpose of this study Potential (quantification) for mass reduction Overview of concepts/approaches Total mass savings Impact on costs Summary

3 DEFINITION OF TSP s Pre-welded structures for subsequent forming (i.e. stamping, hydro-forming, etc.) - Laser welded blanks or tubes - Mash seam welded blanks - Patch welded structures - Tailor rolled structures Allow use of different: - Steels (Mild Steel, HSS & AHSS) - Thicknesses Provide engineering flexibility for locating high strengths at critical locations - Cost effective - Minimize mass

4 DESCRIPTION OF TSPA Alliance: Tailored Steel Blank Manufacturers, Equipment Suppliers, North American Steel Companies. Purpose: To promote the use of tailored steel products in automotive applications.

5 TSPA MEMBERS Tailored Blank Manufacturers Noble International Nova-Hyfo Powerlasers ProCoil Company, LLC Shiloh Industries, Inc. TWB Company, LLC Equipment Suppliers Soutec Soudronic TRUMPF VIL/Wayne Trail Technologies North American Steel Companies AK Steel Corporation ArcelorMittal Nucor Corporation Severstal North America, Inc. United States Steel Corporation

6 TSPA TYPICAL PROJECTS Market Analysis Applications Materials Communications Benefits Development Programs Cost Model Applications Database

7 AUTOMOTIVE REQUIREMENTS Cost Minimization Materials Manufacturing Increased Engineering Performance Crash Stiffness / Ride Durability Environmental Requirements Mass Reduction How can TSPs help reduce mass?

8 INTRODUCTION Purpose Scope Review conceptual & actual approaches in using Tailored Steel Products (TSPs) Primary focus: Secondary focus: MASS SAVINGS Cost Source of information for concepts Members studies and prior proposals/ideas Examples from actual vehicles Organizational studies (AISI-ULSAB, A/SP, etc.)

9 METHODOLOGY Method Select specific areas of the vehicle most likely to offer mass reduction opportunities from TSPs: Body Side Structure Body Side Inner Body Side Outer B-pillar Reinforcement Rails Front/rear Connections to pans Floor Structure Floor/Rear Pans Wheelhouse Inner Motor Compartment Shock Tower Roof Structure Bumper Systems Bumper Beam Crush Box Closures Door Inners Side Impact Beam Life-gate Sub-frames Engine Cradle Rear Sub Frame Others Wheels Lower Control Arm Axle Mount Identify: Mass reduction ranges specific parts Sum the primary mass savings full vehicle Estimate secondary / total mass savings from BIW

10 OVERVIEW OF CONCEPTS Body-Side Structure Rails Sub-frames Other areas (not reviewed here) Front-end structures Motor compartment Roof structure Bumper systems Wheels Lower control areas Axle mounts

BODY SIDE STRUCTURE Body Side Inner Illustrative Example BSI and Reinforcement Ring (Member company concept) Part reduction: 17 to 7 Multiple steel grades Mass

11 BODY SIDE STRUCTURE Body Side Inner Illustrative Example BSI and Reinforcement Ring (Member company concept) Part reduction: 17 to 7 Multiple steel grades Mass reduction 13 to 15# Improved roof crush and side impact performance Lower variable cost and investment cost Manageable press loads compared with a single LWB inner

12 BODY SIDE STRUCTURE Body Side Outer (Exposed) Generic Example: 4-piece single LWB Exposed Quality Laser Welding Typical Body Side Outer & Reinforcements Future Body Side Outer Exposed Quality DP500 Steel Exposed Laser Welds Mass savings pounds/vehicle

13 BODY SIDE STRUCTURE Body Side Outer Other Options: Ford F-150 Door Opening Panel FORD F-150 DOP 1.1mm EG coating & 2mm HD coating Class 2 exposed BENEFITS Eliminated 8 reinforcements, 20 stampings and 88 stamping dies Improved stiffness Improved material utilization Mass savings Part reduction Mass savings/ vehicle = 59 pounds Reduced cost Good surface appearance of weld seam in semiexposed door location

14 BODY SIDE STRUCTURE B-Pillar Reinforcement Illustrative Example Hot stamped LWB of HSLA and Boron Steel (2-piece Audi A5) Boron steel HSLA 350 Mass savings = 4 pounds/vehicle

15 BODY SIDE STRUCTURE B-Pillar Reinforcement (continued) Illustrative Example Hot stamped LWB of HSLA and Boron Steel (2-piece Renault Laguna III Euro Car Body Conference 2007) Mass Saving /vehicle 3.5 kg 7.7 pounds

16 BODY SIDE STRUCTURE B-Pillar Reinforcement (continued) Other Options: Hot formed multi diameter tubular structure (member concept) Mass Saving /vehicle 1.6 pounds

17 RAILS Front Rails Illustrative Example: A/SP Light Weight Front End Structure (LWFES) study (Baseline: GM 2004 Malibu)

yield substantial mass reduction and some cost

18 RAILS Front Rails (continued) Illustrative Example: A/SP LWFES study: Stamping and Tubular options yield substantial mass reduction and some cost reduction. Mass savings (incl. bumper) = pounds/vehicle

19 RAIL INTEGRATIONS Rail to Floor Pan Illustrative Example: Redesign to allow integration with floor pan new Honda Accord Mass Saving /vehicle 6-7 pounds Euro. Car Body Conference 2007

20 SUB-FRAMES Engine Cradle Illustrative Example: Stamped Approach: plasma arc welded LWB (Yorosu/Nissan 2006 MY Metalforming Magazine April 2007) 8 pieces 1 to 2.9 mm thickness Mass savings = pounds

21 SUB-FRAMES Engine Cradle (continued) Other Option: Tubular Approach: HSS replacing Al die casting (Mercedes C-Class Euro. Car Body Conference 2007)

22 IMPACT ON MASS/VEHICLE Category Parts Estimated Mass Savings (pounds) Body in White Body Side Inner Body Side Structure Body Side Outer B-Pillar Rails Front rails (incl. bumper beam) Rear rails Rail/Pan Connection Floor/End Structures Floor/Rear pans 6-10 Wheelhouse inner 4-7 Dash panel Motor Compartment Shock Tower BIW = Roof Structure Sunroof Bumper Systems Bumper beam (1-4) Crash Box Bumpers = 3-5 Closures Door inners (4 doors) 4 8 Side Impact Beam (4 doors) 3 4 Lift gate Closures Sub-Frames Engine cradle Rear sub-frame Sub-frames Others Wheels Lower Control Arm 4 6 Axle Mount 2 4 Others TOTAL

23 MASS SAVINGS BIW and CLOSURES For BIW and Closures: survey has identified: pounds of Primary Mass Savings Additional Secondary Mass Savings No Resizing of Power Train Resizing of Power Train 0.5x Primary* 1.5x Primary* *Recent study by Auto / Steel Partnership - Future Generation Passenger Compartment Team

24 TOTAL MASS SAVINGS Est. Pounds/vehicle Estimated BIW & Closures mass savings Total estimated primary mass savings Additional secondary mass savings No Power Train Resizing (0.5 x Primary) * With Power Train Resizing (1.5 x Primary) * Total mass savings *Based on a recent study by the A/SP Future Generation Passenger Compartment Team

25 IMPACT OF TSP s ON COST TSPA has developed a cost model to compare the application costs of TSP s with conventional processes: Process-based Cost Methodology (MIT) Excel spreadsheet format User friendly 3 Case studies evaluated Door inner Body side inner Front rails All showed: - Lower cost for TSP s - Lower mass

26 TSPA COST MODEL DOOR INNER CASE STUDY 11 (279) Baseline LWB 22.8 (579) 22.8 (579) Mirror Support Gauge = (1.2) 31.5 (800) 50.5 (1283) 31.5 (800) 39.6 (1007) 50.5 (1283) 11 (279) Hinge Reinforcement Gauge = (1.2) 55 (1410) Inner Gauge = (0.7) (Dimensions in parentheses in mm) 14 (356) 41.5 (1054) 55 (1410) Inner Gauge = (1.5) - Left (0.7) - Right

27 DOOR INNER DESIGN CONTENT Baseline LWB # of Parts Weight (kg) Stampings # of Parts Weight (kg) Tailored Blanks TOTAL # of Spot Welds 50 0 Includes left and right assemblies Same materials in both designs (mild steel).

28 UNIT COST (275K VEHICLES / YEAR) Total Unit Cost $, (L & R assemblies) Door Inners Base LWB Total Cost: Other Labor & Equipment Variable & Fixed* Tooling Base LWB Blank Material Blanking Welding * Variable: Energy, process material costs Fixed: Building, maintenance, overhead

29 DOOR INNER TOOLING INVESTMENT COSTS Fixed Investment $ millions Baseline LWB LWB saves $1.28 million or 43%

30 SUMMARY Tailored Steel Products (TSPs) offer the potential for substantial mass savings: Up to 230 pounds (105 kg) without power train resizing Up to 380 pounds (173 kg) with power train resizing

31 SUMMARY Additional benefits can be realized by using TSPs Optimized performance Increased stiffness Improved safety / crash Selected use of different steels / different thickness The right steel for the right location Reduced cost Improved material utilization Reduced manufacturing / assembly costs Reduced tooling costs TSPs a powerful, cost-effective technology

32 MORE INFORMATION CONTACT: Peter R. Mould Program Manager TSPA (810) VISIT:

w w w. a u t o s t e e l. o r g

w w w. a u t o s t e e l. o r g Great Designs in Steel is Sponsored by: ArcelorMittal Dofasco, ArcelorMittal USA, Nucor Corporation, Severstal North America, Inc. and United States Steel Corporation 1 Tailored Steel Products A Smart