2 Center for Precision Forming - CPF CPF is supported by NSF and 16 member companies, interested in metal forming.
3 CPF – Current Projects Material Characterization Friction / LubricationProcess Simulation / Forming Al & AHSSDie Wear in Forming AHSSEdge Quality in Blanking / ShearingHot Stamping of UHSSServo Drive Presses and Hydraulic Cushions3
9 Summary of Hot Stamping Indirect Process:Direct Process:
10 Hot Stamping - Trends ≈ Mass % of hot stamped steel in BIW Audi A3 26%Volvo XC9044%Volvo V4020%Volvo XC907%VW Golf VII28%SAAB 9000VW Passat19%≈19842003200620122014Ref: Lund 2009, Holzkamp 2011, Lindh 2011, Bielz 2012, Mattsson 2012, VW Media Services.
11 Hot Stamping - Trends 210+ lines around the world +55 planned Parts per year (in millions)>20 Parts/ Vehicle6 Parts/ Vehicle8-10 Parts/ Vehicle450 million per year (2013)4 Parts/ Vehicle95 million per year (2007)8 million per year (1997)3 million per year (1987)210+ lines around the world+55 plannedRef: Oldenburg 2010, Hund 2011.
12 Hot Stamping - Trends Passenger Zone Deformation (b) Side view after crash(a) Front viewbefore crashRef: Macek 2006, Image from: IIHS.
13 Hot Stamping - Trends Tailor Rolled Blanks Tailor Welded Blanks Tailored Hot StampingRef: Rehse 2006, Hilfrich 2008, Lee 2012, Images from: IIHS, VW Media Services.
16 Finite Element Simulation of Hot Stamping Our simulations aim to predict the final properties of hot stamped components:Presence of defects: cracks, wrinkles or local necking,Hardness distribution (both in uniform and in tailored parts),Cooling channel analysis,Distortion of the final part.
17 Finite Element Simulation of Hot Stamping Fluid MechanicsHeat transfer to the coolant medium.Heat generation due to plastic deformation.Mechanical FieldThermal FieldThermal expansion.- Mechanical material properties, - Volume change due to phase transformation.Phase transformation depends on stress and strain.Microstructure depends on temperature.- Thermal material properties,- Latent heat due to phase transformation.Microstructure EvolutionRef: Åkerström 2006, Porzner 2012.
18 Finite Element Simulation of Hot Stamping Only needed in tailored parts
19 Predicting Defects Colors other than gray: Thinning >20%. Crack prediction in a Side Member ReinforcementColors other than gray:Thinning >20%.Part stamped at the participating company
27 Distortion Analysis Ongoing work: Distortion in Tailored Parts Ref: Porzner 2012.
28 Summary and Conclusions Several case studies were used to develop, calibrate and validate material models, conversion factors and methods to predict:Defects (cracks, wrinkles, local necks),Vickers hardness, yield and ultimate tensile strengths,Cooling channel / heating cartridge performance,Distortion in a non-uniform part.
29 What is next?1) New materials with even higher strength: More lightweight potential and increased productivity.2) New coatings: better corrosion properties and friction conditions.3) New heating, forming and quenching methods to improve productivity.High Strength (USIBOR 2000, MBW1900, HPF 2000)22MnB5 (USIBOR 1500, MBW1500, HPF1470)High Elongation (DUCTIBOR 500, MBW500)Competition: DP, TRIP, TWIP, and 3gAHS Steels with high YS and UTS.Ref: Lanzerath 2011, Vietoris 2011, Ferkel 2012, Lee 2012.
30 Deliverables / Hot Stamping As of September 2013:- 15 CPF Reports (Literature review and FE simulations), (5 in the last 6 months) [confidential to members],- 6 Stamping Journal R&D Updates (+1 more in progress),- 6 Conference Proceedings (+1 more submitted),- 1 Book Chapter in “Sheet Metal Forming: Vol 2: Processes and Applications”, (see next slide),- And a new “Hot Stamping” book in progress!
31 Questions / Comments? For more information , please contact: Dr. Eren Billur PhDr. Taylan Altan PhCenter for Precision Forming –CPF (www.cpforming.org)339 Baker Systems,1971 Neil Ave,Columbus, OH-43210Non-proprietary information can be found at web sites:References can be sent upon request.