worldsteel / CISAChina Automotive Steel Conference Jae-Bok NAM POSCO Technical Research Lab. Development of New Auto Steels and Application Technology Nov. 21, 2013 - 0/26 - POSCO Automotive Steel - 1/26 - 0 0.High strength steel and AHSS are occupied with 44.Sales in 2003 to 2012 has been increasing by CAGR of 11.0 Sales of Automotive Steels.0 Product 4.7% .0 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Coated Product : 33.In 2012.7%. .2/26 - .0 2.0 Steel Grade 3.5% HSS+AHSS : 44.7% of total sales .3 million tons including 62% overseas sales. . total sales is 7. million ton 7.0 6.POSCO Automotive Steel Introduction Automotive Steels in POSCO Sales in 2003~2012 Sales Mix in 2012 8.0 1.0 5. 25.Giga duplex.TWIP steel .000 MPa·% Ultra-AHSS (U-AHSS) . Volume THERMEC 2009.TSxEl > 50.3/26 - .136 . p. HPF . CP.000 MPa·% Tensile strength (MPa) X-AHSS : eXtra-Advanced HSS / U-AHSS : Ultra-Advanced HSS Ref : Ohjoon Kwon.DP. Mart.000 MPa·% eXtra-AHSS (X-AHSS) .TSxEl < 25. Kwang Geun Chin et al : Materials Science Forum. TRIP.000 < TSxEl < 50.POSCO Automotive Steel Development of AHSS Banana Diagram Conventional AHSS Elongation (%) AHSS grade DP/CP TRIP Mart HPF TWIP Duplex/Lightweight IF Status Commercialized Developed Developing Mild BH . Light weight steel . POSCO Automotive Steel 490DP Steel for Outer Panel GA 490DP for Door Outer – World First Production（2005） Requirement : Surface quality. Stiffness 18 0. 0.7mm 17 16 340BH 490DP [ Weight reduction ] Dent load (kgf) Weight (kg) Replacement of 340BH steel by 490DP steel Weight reduction 7%. improvement of dent resistance 53% 25 20 15 10 5 0 + 53% 490DP 340BH [ Improvement of dent resistance ] Applications Body panel reinforcement sealer [ Door outer.7t GA 490DP ] .75mm .7% 0.4/26 - [ Removal of Body panel reinforcement sealer ] . Dent resistance. Fender GA 590DP (0.590DP Steel for Outer Panel POSCO Automotive Steel GA 590DP for Closure Parts Trial for hood outer : 21% weight reduction (0.55t 590DP) Trial for fender at Japanese automobile company shows good formability Applications Small Sedan.7t 340BH 0.5/26 - .55t) [ Hood outer using GA 590DP of 0.55mm thickness ] .55t) Japanese Car. Hood outer GA 590DP (0. 75 ≥180 ≥ 340 ≥ 35 2.25 Application 340E Steel on Korean OEM’s SIDE OTR PNL World’s first commercial application Weight Reduction 7% (EDDQ 0.POSCO Automotive Steel Super Formable IF HSS IF HSS (E/ES-class) High elongation and excellent r-value suitable for outer parts requiring strength & formability Grade 340E 340ES Class CR/EG GI/GA CR/EG GI/GA YS (MPa) TS (MPa) El (%) r ≥167 ≥ 340 ≥ 32 1.6/26 - GI .65t) We have 340ES for better than 340E [ One Piece Side Outer (domestic company) ] .7t 0. 5R 1.0 X X △ △ △ △ O △ 2.3 Bendability ( GA980DP: 2.POSCO Automotive Steel 980DP Steel CR/GI/GA 980DP with good bendability Reduce the strength difference between phases Improvement of bendability Low Ceq decreasing welding nugget hardness Increase of ductility ratio Bending direction Spec.5 ≤ 2.0R 1.7/26 - [ Floor panel tunnel (GI 980DP) ] .0t) 0.5 R/t 1.5 2.5 △ O 3. (R/t) L C ≤ 2.5 1.0 O O Applications [ Back side bracket (CR 980DP) ] [ Cross section of spot welded GA980DP steel ] . TS ≥ 1180 MPa Bending radius ≤ 3 x thickness Low Ceq and Si content 1180CP Suppress ferrite and promote bainite transformation High YR.POSCO Automotive Steel 1180CP Steel GA 1180CP for Reinforcement Parts Requirement Devloping Target High YR Bendability Spot weldability Zn coatability YS ≥ 850 MPa. excellent bending property Applications Martensite Ferrite Material Change (EG 590TRIP GA 1180CP steel) Achieve 33% of weight reduction First commercial production in the world Bainite [ Microstructure ] [ Rocker Outer (Domestic company) ] .8/26 - . 71 ≤6 1) Bendability = Min.POSCO Automotive Steel GI 1470Mart GI 1470Mart for Reinforcement Parts Safety regulation for frontal small overlap crash test : 25% offset collision introduced by IIHS So. www.iihs. rocker or side sill becomes more and more important where anti-corrosion is also significant Commercialization of the world 1st GI 1470 Martensitic steel * cf. corner radius / Thickness Applications Rocker Outer Bumper Beam First commercial production in the world .9/26 - [ Rocker Outer (Domestic company)] .org < Mechanical properties > YS (MPa) TS (MPa) T-El (%) YR Bendability(1） ≥ 1050 ≥ 1470 ≥5 > 0. Low arm : 540MPa FB (4 Ops) 980MPa TWIP (2 Ops) [ Wheel. High El : Wheel. 1300. member etc. 1100.10/26 - [Bumper Beam. 1700 grades) Applications High TS. Chassis with TWIP steel ] . Commercialized product (’12) ] . World First) Developing high YS TWIP steels (900. Commercialized Bumper of European Vehicle (28% weight reduction. Low arm etc . 22% cost saving) High HER. 1500. 65%) Commercialization : Cold rolled product. High El : Bumper. 2011~ (POSCO.POSCO Automotive Steel TWIP Steels (U-AHSS) Characteristics High Mn austenitic steel work-hardened by twinning High energy absorption by excellent strain hardening rate Very high strength-ductility combination (1000MPa. the number of chassis application is increasing as the advantage becomes apparent with TWIP steel. Recently.POSCO Automotive Steel TWIP Steels (U-AHSS) Part development of BIW (body in white) and Chassis Chassis BIW Spring Stopper Wheel Disc & Rim Lower Arm Front Cross Member The red colored parts are made from TWIP steel through collaboration with customers. .11/26 - . . MART HPF 0 200 1200_HY TWIP 1200 60 Stress (MPa) Elongation (%) 70 1400 0 0 400 600 800 1000 1200 1400 Tensile Strength (MPa) 20 40 Strain (%) 60 To meet the customers needs for high YS TWIP steels. . 900_HY. POSCO developed three grades. ★ : Developed ★980TWIP 50 ★ 900TWIP 40 ★900_HY TWIP LC 30 20 10 BH ★1000_HY TWIP 1000_HY TWIP 1000 ★1200_HY TWIP 900_HY TWIP 900TWIP 800 600 400 200 CP.12/26 - 80 .POSCO Automotive Steel TWIP Steels (U-AHSS) Development of TWIP steels with High YS ★ : Commercial. 1000_HY and 1200_HY. which is utilized work hardening by skin pass rolling . POSCO Automotive Steel Medium Mn TRIP steel (X-AHSS) Characteristics Medium Mn addition increase of austenite stability High TS strength. yield ratio and elongation with a large amount of austenite Duplex microstructure of ultra-fine retained austenite and ferrite < Mechanical Properties > YS (MPa) TS (MPa) El (%) TSxEl (MPa%) 980 DP 780 1040 11 11440 980 Duplex 937 1033 28 28924 < Microstructure > 1200 Strength(MPa) 1000 800 600 (TS X El ≥ 25.000MPa%) 400 200 0 Ferrite X-AHSS grade!! Austenite CR 980 Duplex 0 10 20 Strain(%) 30 .13/26 - . POSCO Application Technology New Forming Technology Lightweight Solutions for Chassis POSCO Lightweight Body Concept Electric Power Train .14/26 - . TWB HPF to enhance the ductility in sepecific area Multi-strength HPF HPF1470 (1.6GPa) (1 Piece Blank) TWB HPF HPF1470 Laser welding (1.POSCO Application Tech.6GPa) (TWB Blank) . New Forming Technology Tailored Hot Press Forming Implementation : Multi-strength HPF.5GPa) ③ HSS 590 ① HSS 590 HPF1470 (0.15/26 - .5GPa) ② HSS 380Y [ Conventional Design ] CHSP340Y (0. 16/26 - . New Forming Technology PosRollForm (Multi-Directional Roll Forming) Concept : Producing Variable Sectional Profile using Linear & Rotational Movement of Stands” POSCO’s own FE Program (Shape-MDRF) : Reduction of Calculation Time with High Accuracy Unique Solution for the Prevention of Distortion : Incremental Counter Forming Method Side Sill [Conventional Product] [PosRollForm Product] (Uniform Section) (Variable Section) Floor Cross Member [PosRollForm Test Facility] [PBC-EV PosRollForm Part] .POSCO Application Tech. 17/26 - .Lightweight Solution for Chassis POSCO Application Tech. Torsion Beam Axle Removing reinforcement (bracket) for a lightweight torsion beam Design Optimization and Advanced Manufacturing by Hydroforming Technology New Concept : Bended and Expanded Beam for Structural Performance Project on Torsion Beam Axle Development Original Beam Weight Down+Bracket Removing Design Optimization Durability Test PI Weld Durability Analysis Optimized H/F beam Proto Beam – Hydro forming FB780 One-piece Beam 17 . 6t / 3.Lightweight Solution for Chassis POSCO Application Tech. Styled Steel Wheel Lightweighting by Shape Optimization and Advanced Manufacturing Technology New Concept : High Stiffness Rim (TWIP980 steel + Hydroforming) TWB Disk (HB780 steel.18/26 - 18 TWB Disk .2t) HB780 Wheel Disk TWIP980 Wheel Rim Structural / Durability analysis Die design & Forming Analysis Styled Steel wheel TWIP980 – Rim Bead Optimization .3. Width 1830mm.285 [ Computational Fluid Dynamic (CFD) simulation ] . to provide Cost Efficient Steel Solutions for electric vehicle to our customers To identify Requirements of New Steel Grades and New Opportunities for Steel Dimensions Overall Length 4320mm. PBC-EV : POSCO Body Concept-Electric Vehicle Objectives To integrate POSCO’s steel products & application tech. Wheelbase 2750mm.POSCO Body Concept : PBC-EV POSCO Application Tech. Height 1550mm [ Final Styling ] Styling & Packages CFD Based Styling for Optimal Surface Streamline Separated Air Flow Aerodynamic Design High Roof Package for Maximizing Passenger/Battery Spaces Detachable Rear Battery Package Cd = 0.19/26 - . 1.2.4 % * Body Weight : Without Bumper Impact Beam . 8.2% 15. Dynamic Bending/Torsion = 51.20/26 - .3% TRIP590. Body Weight : 218 kg Weight Reduction : 26. 32.1180. POSCO Body Concept : PBC-EV PBC-EV Base Model Design Results Weight Reduction : 26. No Battery Damage [Stiffness] Static Bending/Torsion > 15000.4% Performance : [Crash] 5 Star & Good Safety Rating.5% Mg(Sheet).53% E-ES/C/R Class.3% DP980. DP490/590/780. 0.4% TRIP980.6% 10.9% 9. 10.6% CP1180/1470.2.2/47.3% AHSS = 65. TWIP980.4% 3. DUPLEX3.0% ETC.4Hz Steel Grades Steel Grades (As % of Body Weight) MILD.POSCO Application Tech.9% HPF1470/2000.0 % UHSS(≥1GPa) = 45. 2 % (Including PosRollForm) .21/26 - .POSCO Body Concept : PBC-EV POSCO Application Tech. Manufacturing Process Manufacturing Process (As % of BIW Structure Mass) Cost Efficient Manufacturing Roll Forming + Forming = 41. 22/26 - . Demonstration Transition line Weldability Test Assembly Process Design & Formability Analysis Ductile Zone Hard Zone Weld-line HPF1470 CHSP340Y Process Optimization & Prototyping Prototyping World 1st Body Concept for Electric Vehicle By Steel Company .POSCO Body Concept : PBC-EV POSCO Application Tech. 4% 50. High Torsional Stiffness Model (kN/deg) • Torsional Stiffness Improvement : 17.2 25.2 17.1%) Final Weight Savings 30% Modified Parts Design Modification for Extra Lightweight Torsional Stiffness 3.8 216kg 207kg 218kg PBC-EV Base Extra Light.1% 2. Extra Lightweight Model • Additional Lightweight by Structure Improvement and Increase of HPF Parts (HPF ratio in BIW : 8. Upgraded Models 1.23/26 - 50% 20. .4% 1.2 25.8 kN/deg) 17. High Stiff.POSCO Body Concept : PBC-EV POSCO Application Tech.0% (17.03 • Effective Solution for RCAR Structural Tests 2.3% RCAR Front/Rear Structural Test (CAE Result) 2. Solution for RCAR Test ※ Max.2 Analysis of Strain Energy & Thickness Sensitiveness .9% LH : 2. Effective Plastic Strain < 0. PCU Applications to EV (Electric Vehicle) • EV Conversion for EPT Test .Road Driving Test • Mid-size EV Buildup with Customer • Small Size EV Development in Consortium POSCO EPT Applications . EPT (Electric Power Train) * PMSM : Permanent Magnet Synchronous Motor POSCO EPT system High Performance and Reliability : PMSM EPT System with High Power Density & High Efficiency Compact Light Weight Low Cost Easy Installation High Power Density Key Factor for EV Optimized Design Parts Integration Products 100kW EPT – PMSM.POSCO Application Tech.24/26 - .Various Performance Evaluations . PCU 60kW EPT – PMSM. Torque : 320Nm/90sec .EPT (Electric Power Train) POSCO Application Tech. 260mm. 100kW PMSM Major Specifications . Torque Continuous Power Motor Speed (rpm) Power (kW) Torque (Nm) Max Torque 60kW is available stably for whole speed range * Avg.6kW/kg Performance T-N Curve Efficiency Map 100kW T-N characteristic 100kW output Max Power Cont. efficiency (UDDS LA4mode) : 92% .25/26 - . Weight 62kg) .000rpm .Max. 95% efficiency in most frequent usable operating ** Avg.600rpm/90sec .Motor Type : Interior Permanent Magnet .Continuous Power : 60kW@0~12. 12ℓ/min) 100kW PMSM (L 286mm H 325mm Stator Dia.Power Density : 1. Power : [email protected] : Water (65Ԩ.Max. Concluding Remarks POSCO has been developing new advanced materials and application technologies for vehicle lightweighting POSCO develops new technologies. utilizing external as well as internal resources for customer value creation POSCO Global R&D Network .26/26 - .