Institute for Metal Forming Technology Prof. Dr.-Ing. Dr. h.c. Klaus Siegert Prof. Dr.-Ing. Dr. h.c. Klaus Siegert Dipl.-Ing. M. Vulcan Tool and Die Design for Deep Drawing AHSS
Jan 20, 2016
Institute for Metal Forming TechnologyProf. Dr.-Ing. Dr. h.c. Klaus Siegert
Prof. Dr.-Ing. Dr. h.c. Klaus SiegertDipl.-Ing. M. Vulcan
Tool and Die Design for Deep Drawing AHSS
WagnerS-2005-03 (2)
Stuttgart UniversityInstitute for Metal Forming Technology
High Strength Steel Sheets
Cushion Systems and Die Design
Stretch Drawing of Flat Parts
Controllable Draw Beads
Summary
WagnerS-2005-03 (3)
Stuttgart UniversityInstitute for Metal Forming Technology
1975 1975 1980 1980 1985 1985 1990 1990 1995 1995 20002000
Source: ThyssenDevelopment of High Strength Steels
Increase of strength by microstructural changeMultiphase Steel
Concerted control of grain refining by addingTitanium
Isotropic Steel
Solid solution hardeningHigher-Strength IF-Steel
Diffusion of interst. N und C to increase the yield strength
Bake Hardening Steel
Embedding hard martensite parts in ferritic matrixDual Phase Steel
Solid solution hardening by adding phosphorusPhosphorus-Alloyed Steel
Hardening by carbides of micro alloy elements Ti, Nb, V
Micro-Alloyed Steel
WagnerS-2005-03 (4)
Stuttgart UniversityInstitute for Metal Forming Technology
El
onga
tion
atFr
actu
reA
80 (%
)
Tensile Strength Rm (MPa)
50
0
10
20
30
40
60
200 300 400 500 600 700 800 900
TRIP - SteelTRIP 700TRIP 800
IF- SteelIF 180IF 260
Bake Hardening -
SteelHSLA 180BHHSLA 300BH
Micro AlloyedHSLA 260HSLA 420
Phosphoralloyed
HSLA 220PHSLA 300P
1000 1100
IsotropicHSLA 220iHSLA 280i
Complex-Phase -Steel
CP-W 800CP-W 1000
Martensite-Steel
MS-W 1000MS-W 1200
Dual-PhaseSteel
DP 500DP 600
Comparison of Different Steel Grades
WagnerS-2005-03 (5)
Stuttgart UniversityInstitute for Metal Forming Technology
Source: IFU
Flow Curves of Actual Sheet Metals
FePO4
200
500
0,10
700
kf
900
[N/mm²]
0,150 gϕ
100
300
400
600
IF 260
DP 500DP 600
TRIP 700
0,05Logarithmic True Strain
WagnerS-2005-03 (6)
Stuttgart UniversityInstitute for Metal Forming Technology
Source: Birzer
0,923574381DP 600
rm = 1,530400320280220HSLA 220 BH
10869567DP 800
0,7613501150MS 1200
14903793CP 800
0,820-30850680TRIP 700
16735583DP 700
High and Advanced High Strength Steels
rm = 1,326480400360300HSLA 300 BH
rm = 1,428440360320260HSLA 260 BH
rm = 1,932380300240180HSLA 180 BH
High Strength Bake-Hardening Steels
90°45°0°maxminmaxmin
R-ValueElong. at Fracture A80 in %
UTS in MPaYield Strength in MPa
WagnerS-2005-03 (7)
Stuttgart UniversityInstitute for Metal Forming Technology
High Strength Steel Sheets
Cushion Systems and Die Design
Stretch Drawing of Flat Parts
Controllable Draw Beads
Summary
WagnerS-2005-03 (8)
Stuttgart UniversityInstitute for Metal Forming Technology
GripperBlankholder
Hydraulic ValvesPunch
Frame
Source: T. Krockenberger, IFU
Test Equipment for Stretch Drawing followed by Deep Drawing
WagnerS-2005-03 (9)
Stuttgart UniversityInstitute for Metal Forming Technology
Test Equipment for Stretch Drawing followed by Deep Drawing,Installed in Single Acting Hydraulic Press at IFU
Source: T. Krockenberger, IFU
WagnerS-2005-03 (10)
Stuttgart UniversityInstitute for Metal Forming Technology
Source: D. Vlahovic, IFU
First Stage: Clamping the Sheet
WagnerS-2005-03 (11)
Stuttgart UniversityInstitute for Metal Forming Technology
Source: D. Vlahovic, IFU
Second Stage: Predefined Stretching of the Sheet
WagnerS-2005-03 (12)
Stuttgart UniversityInstitute for Metal Forming Technology
Source: D. Vlahovic, IFU
Third Stage: Tool Closing
WagnerS-2005-03 (13)
Stuttgart UniversityInstitute for Metal Forming Technology
Source: D. Vlahovic, IFU
Last Stage: Deep Drawing of the Sun Roof Panel
WagnerS-2005-03 (14)
Stuttgart UniversityInstitute for Metal Forming Technology
Principal Strain after Deep Drawing
Source: D. Vlahovic, IFU
Results FEM Process Simulation
Principal Strain after Pre-Stretching
WagnerS-2005-03 (15)
Stuttgart UniversityInstitute for Metal Forming Technology
High Strength Steel Sheets
Cushion Systems and Die Design
Stretch Drawing of Flat Parts
Controllable Draw Beads
Summary
WagnerS-2005-03 (16)
Stuttgart UniversityInstitute for Metal Forming Technology
Springback Reduction:
Increased Wall Stresses in the Straight Sides by Driving the Active Drawbeads Upwards.
Guideline: σWall< 0,8 σFracture
SafetyFactor
σFracture
σz, Wall, Basic
σz, Wall, Drawbead
Safety Distance
Desired Wall Stress DistributionSource: S. Beck, IFU
WagnerS-2005-03 (17)
Stuttgart UniversityInstitute for Metal Forming Technology
Safety Distance
Additional Force by IncreasedBlankholder Force and/orIncreased Drawbead Height
Intention: Improved Wall Quality by Introducing Additional Forces
Desired Punch Force TrajectorySource: S. Beck, IFU
WagnerS-2005-03 (18)
Stuttgart UniversityInstitute for Metal Forming Technology
Side Wall Stress SensorSource: S. Beck, IFU
Elastic Hinge
Load Cell
Force in theSheet
Vertical Force Horizontal Force
in the Sheet(Restraining Force)
Side Wall StressSensor
Punch
WagnerS-2005-03 (19)
Stuttgart UniversityInstitute for Metal Forming Technology
Drawbead 3 Connected
Drawbead 4
Drawbead 1
Drawbead 2
Optional
Sensor
Position of the Wall Stress Sensors and Position of the DrawbeadsSource: S. Beck, IFU
WagnerS-2005-03 (20)
Stuttgart UniversityInstitute for Metal Forming Technology
Stroke in mm
Stre
ssin
N/m
m2
0
50
100
150
200
250
300
350
0 20 40 60 80 100 120
Stress 1Stress 2Stress 3Stress 4
Stress at Fracture
Side Wall Stress vs. Stroke for Constant Draw Bead HeightsQuelle: S. Beck, IFU
WagnerS-2005-03 (21)
Stuttgart UniversityInstitute for Metal Forming Technology
R
r = 1/R
Curvature of the Side Wall for Variable Draw Bead Heights vs. StrokeSource: S. Beck, IFU
WagnerS-2005-03 (22)
Stuttgart UniversityInstitute for Metal Forming Technology
Springback Phenomena when Drawing U-ProfilesSource: M. Beth
WagnerS-2005-03 (23)
Stuttgart UniversityInstitute for Metal Forming Technology
Sidewall of the Part, drawn without Drawbeads
Sidewall of the Part, drawn with Controllable Drawbeads
Surface Quality with and without Controllable Drawbeads(Measured with the System Diffracto)
Source: S. Beck, IFU
WagnerS-2005-03 (24)
Stuttgart UniversityInstitute for Metal Forming Technology
High Strength Steel Sheets
Cushion Systems and Die Design
Stretch Drawing of Flat Parts
Controllable Draw Beads
Summary
WagnerS-2005-03 (25)
Stuttgart UniversityInstitute for Metal Forming Technology
Design of Conventional Draw Dies
Box-Profile
C-Profile
Source: M. Häussermann, IFU
WagnerS-2005-03 (26)
Stuttgart UniversityInstitute for Metal Forming Technology
Blankholder Pressure by the Box-Profile
Blankholder Pressure: 4 ... ... 0 N/mm24 ...4 ... ... 0 N/mm... 0 N/mm22
Source: M. Häussermann, IFU
WagnerS-2005-03 (27)
Stuttgart UniversityInstitute for Metal Forming Technology
Principle of the Segment-Elastic Blankholder
Draw Ring
Blankholder
Blank
FPin FPin FPin
Locally increased Blankholder Pressure
FPin, increased
Source: M. Häussermann, IFU
WagnerS-2005-03 (28)
Stuttgart UniversityInstitute for Metal Forming Technology
Prismatc DesignedDraw Ring
Return StrokeCylinders
Segment-Eelastic Blankholder
Servo Valves
Hydraulic Cylinders
Guide
Punch
StrokeMeasurement
Bottom Plate
Source: M. Häussermann, IFU
Draw Die with Segment-Elastic Blankholder,Prismatic Designed Draw Ring and 10-Point
Cushion System Integrated into the Die
WagnerS-2005-03 (29)
Stuttgart UniversityInstitute for Metal Forming Technology
Hydraulic Multipoint Cushion System in the Die
Source: M. Häussermann, IFU
WagnerS-2005-03 (30)
Stuttgart UniversityInstitute for Metal Forming Technology
Normal Pressure: 4,5 ... ... 0 N/mm2
Source: M. Häussermann, IFU
EqualPin Forces
Increase of100% in theMiddle Area
WagnerS-2005-03 (31)
Stuttgart UniversityInstitute for Metal Forming Technology
Optimization of the Cushion Pin Forces
2 kN90 kN 98 kN
52 kN
24 kN
13 kN99 kN102 kN7 kN
43 kN
Total Blankholder Force 530kN Good Part with 68 mm Draw Depth
Source: M. Häussermann, IFU
WagnerS-2005-03 (32)
Stuttgart UniversityInstitute for Metal Forming Technology
Punch
Blankholder
Cables and sensors
Valves
18 Nytrogen Cylinders
Source: D. Haller, IFU
Die for the Deep Drawing of Longitudinal Beams with Cushion
System integrated into the Die
WagnerS-2005-03 (33)
Stuttgart UniversityInstitute for Metal Forming Technology
Source: D. Haller, IFU
Die for the Deep Drawing of Longitudinal Beams with Cushion
System integrated into the Die
WagnerS-2005-03 (34)
Stuttgart UniversityInstitute for Metal Forming Technology
Experimental Die
Source: J. Hengelhaupt, IFU
Stuttgart UniversityInstitute for Metal Forming Technology
WagnerS-2005-03 (35)
Stuttgart UniversityInstitute for Metal Forming Technology
MOOG Controller Units
HydraulicHMI
HYDACPowerUnit
Main MobileHydraulic Unit
Cooling System
10 Point Flexible Binder Die
2 x Return Tank Units 2 x Bladder Accumulators Station(each 1 x 60 bar and
2 x 10 bar)
IFUHMI
20.000 kNHydraulic Press at
the IFU
PressHMI
Source: IFU
WagnerS-2005-03 (36)
Stuttgart UniversityInstitute for Metal Forming Technology
Source: M. Vulcan, IFUControl system with Touch Screen to Adjust
the Blankholder Pressure Area by Area
WagnerS-2005-03 (37)
Stuttgart UniversityInstitute for Metal Forming Technology
Source: IFU
Design of Closed Loop Control of the BHF
Nominal Value
Stroke
Controller
Cushion System integratedinto the Die
Segment-elasticBlankholder
Actual Values
Ram
Upper Binder
MeasuringFrictionForce andWrinkleHeight
Friction Force versus the StrokeMax. Wrinkle Height
WagnerS-2005-03 (38)
Stuttgart UniversityInstitute for Metal Forming Technology
Tool and Die Design for
Deep DrawingAHSS
WagnerS-2005-03 (39)
Stuttgart UniversityInstitute for Metal Forming Technology
w w w . a u t o s t e e l . o r g
Great Designs in Steel is Sponsored by:•AK Steel Corporation•Dofasco Inc.
•Severstal North America Inc.•United States Steel Corporation
•Mittal Steel Company•Nucor Corporation