Validating NEXMET AHSS as a Lightweight Steel Solution

Transcription

1 Validating NEXMET AHSS as a Lightweight Steel Solution Scott Stevens AK Steel Corporation GDIS2018

2 Agenda Recap of NEXMET 1000 & 1200 AHSS Qualification & Characterization Applications under development Focused Study: Roof Bow & Door Beam Other considerations Q&A 2

3 NEXMET 1000 & 1200 AHSS 3

4 HDGI Mechanical Properties Grade Yield Strength, MPa Tensile Strength, MPa Total Elongation, % Uniform Elongation, % n-value (4-6%) n-value (10%- uniform strain) NEXMET 1000 NEXMET Grade NEXMET 1000 NEXMET Bend, Pass at r/t VDA Bend Test Hole Expansion Ratio, % Parallel Normal Parallel Normal

5 Global Formability Tensile Strength (MPa) vs Draw Depth (mm) Dual Phase NEXMET 1000 NEXMET

6 FLC Comparison 6

7 Springback Forming with no bead Forming with draw bead Forming with stake bead Setup Springback Setup Springback Setup Springback Forming with stake bead shows the best springback control 7

8 Fused Diameter (mm) Weld Testing 8 Good current range and electrode life Occasional LME cracking at highest current ST No Crack ST Crack CT No Crack CT Crack MWS Expulsion Current (ka)

9 Peak Load (kn) Peak Load (kn) Weld Mechanical Properties No Crack Crack MWS Fusion Zone (mm) Expulsion MWS Expulsion No Crack Crack Fusion Zone (mm) NEXMET 1000 Shear Tension NEXMET 1000 Cross Tension 9

10 High Strain Rate Testing Zwick HTM16020 High Strain Rate Test Frame 10

11 Early-Adopter OEM Qualifications complete by mid-year Full Commercialization to coincide CR/Uncoated To follow HDGI later this year GA In development Timing Product Development Validation Commercialization 11

12 Applications Under Development Part Front Panel Roof Bow PNL BD Lower Front Member Cross Bar Door Beam Base Material Base Gauge New Material New Gauge Pass FEA Prototype Attribute DP mm NEXMET mm Yes Yes Performance DP mm NEXMET mm Yes Yes Mass Saving DP mm NEXMET mm Yes TBD Mass Savings DP mm NEXMET mm Yes TBD Mass Savings DP mm NEXMET mm Yes Yes Mass Savings PHS 1.8mm NEXMET mm Yes Yes Performance 12 Striker Anchor Plate Reinf RKR INR DP mm NEXMET mm Yes Yes Formability / Springback DP mm NEXMET mm Yes Yes Mass Savings

13 Forming Feasibility for Stamped Parts Additional Work, OEM Directed 13

14 Forming Feasibility for Stamped Parts Additional Work, OEM Directed Laser Welding and Blank Development 14

15 Forming Feasibility for Stamped Parts Additional Work, OEM Directed Laser Welding Development Tubing and Hydroforming 15

16 Roof Bow Application Stamping FEA and Correlation Springback Prediction and Correlation Performance Comparison 3 Point Bend Modeling, Testing & Correlation Gauge Optimization Total Mass Savings 16

17 Stamping Feasibility Die Design 17 NEXMET 1200 FLC Plastic Strain Max: Formability

18 Stamping Springback Correlation Scan Thickness Changes - Simulation vs. Tryout FEA EP FEA KH 18

19 3 Point Bend Test and CAE Simulation Not Actual Speed 3 Point Bend Test mm 3 NEXMET 1.6 mm mm Nonlinear analysis using LS-Dyna to predict the load vs. deflection behavior in test 19

20 Test to CAE Correlation DP mm NEXMET mm PHS 1.8 mm 20

21 MATERIAL MATERIAL TEST Optimization Results PEAK LOAD (kn) SIMULATION DP mm NEXMET mm PHS 1.8 mm GAUGE (mm) WEIGHT (Kg) GAUGE OPTIMIZATION WEIGHT REDUCTION (Kg) WEIGHT REDUCTION % TEST PEAK LOAD (KN) SIMULATION DP 980 Baseline NEXMET PHS

22 Door Beam Study Cold Stamping NEXMET 1200 in Hot Stamp Die 22

23 3 Point Bend Test and CAE Simulation 23

24 In Conclusion GI NEXMET 1000 & 1200 AHSS Qualified & Commercially Available by Mid-Year Formability & Springback Correlated Performance Verified Alternative to PHS Mass Savings Confirmed 24

25 Committed to Automotive Scott Stevens AK Steel Corporation Jon Powers AK Steel Corporation