Potential for Mn in New Automotive Steels

1

• Potential for Mn in New Automotive Steels

2
Hot Rolled Products Overview and Evolution
Increase Strength-Ductility Balance Availability
of very HSS in low thicknesses Precoated Products
Elongation ()

4
0
USIFORM 450-550
Trend
3
5
USIPHASE D550
USIPHASE D 600
USIPHASE T 800
3
0
USIPHASE D800
2
5
USIDUR
3
1
5
-
420
USIFORM 600
USIDUR 700
2
0
Trend
USIPHASE M 800 (t 1.6 mm)
1
5
Trend to low thicknesses
USIPHASE M 1000 (t 1.6 mm)
1
0
1100 T.S. Mpa
4
0
0







5
0
0







6
0
0







7
0
0







8
0
0







9
0
0






1
0
0
0
3
Colled rolled steels
1000
TRIP Dual Phase Dual Phase HSS
900
800
Microalloyed (HSLA)
HS
Isotropic
Bake-Hardening (HS BH)
700
IF HS
TS (MPa)
Rephosphorized
USISTAMP06
600
USISTAMP07
500
400
300
El ( )
4
Floor Panel in EDDQ Steel
5
Seat Stand
6
Dual Phase Microstructure
USIPHASE D 600Ferrite Martensite
7
TRIP Microstructure
USIPHASE T 800Ferrite Bainite Residual
Austenite
8
Arcelor Offer Ts 600MPa
9
Arcelor Offer Ts 800MPa
35
30
Usiphase T800
Usiphase T800
B/EZ
B/EZ
25
Usiphase D80
Total elongation
B/ EZ(lt3mm)
Usiphase D750
B/HDG/ EZ(lt2mm)
20
15
Usiphase M800
B/ EZ(lt3mm) /HDG(lt3mm)
10
0
1
2
3
4
5
Available thicknesses (mm)
10
Arcelor Offer Ts 1000MPa
30
B/ EZ
25
Usiphase T1000
20
Total elongation
15
Usiphase M1000

B/ HDG
10
5
0
1
2
3
4
5
Available thicknesses (mm)
11
Dimensioning Stresses
Processing Constraints
Stiffness E
Crash (YS, TS, El, n)
Fatigue (TS)
Exceptional Stresses (YS, E)
Profilage
Welding
Stamping
Stretch flanging





Wheel Rims




Wheel disks





Suspension arms





Engine cradles





Rear Axle
Chassis Parts
12
Hole Expansion Ratio

'

(
A
C


(
D
-
D
o
)
/
D
o

x
1
0
0
)
)
Die
1
8
0
USIFORM 450-550
Punch
1
6
0
USIDUR
3
1
5
-
5
5
0
1
4
0
USIFORM 600
Nakazima-Hecker Method
1
2
0
1
0
0
USIFORM 800
8
0

T.S.

(MPa)
4
0
0







5
0
0







6
0
0







7
0
0







8
0
0







9
0
0






1
0
0
0
13
DENT RESISTANCE INTEREST OF BAKE-HARDENINGSTEEL
GRADESUSIPLUS
Load 400N (rubber punch diameter 15 mm
hardness 80 shore)
14
BH and Ageing Behaviour of DP and TRIP Steels
Bake Hardening 170C / 20mn
Aging 70C / 10H
MPa
MPa
100
100
DP450
80
80
DP500
60
60
DP600
40
40
BH after Tensile Test
DP750
Ageing after T.T.
TRIP800
20
20
BH after SkP
0
0
Ageing après SkP
0
2
4
6
8
10
12
14
0
2
4
6
8
10
Predeformation ()
predeformation
- No ageing and low BH without predeformation -
High BH after predeformation
15
Crash Energy Management
Anti Intrusion
Energy Absorption
16
Weight reduction potential in flexion vs.
USISTAMP 04 ()
60,00
50,00
40,00
30,00
Ultimate force
58
49
47
20,00
37
34
33
32
24
23
10,00
20
19
10
9
0
0,00
HLE500
Usidur315
Usistamp04
Usiphor280
Usidraw440
Usibor 1500
UsiphaseT800
UsiphaseD450
UsiphaseD500
UsiphaseD600
UsiphaseD750
UsiphaseM800
UsiphaseM1000
UsiphaseTR1000
17
(No Transcript)
18
DP and TRIP typical mechanical properties
TRIP800
900
DP750
800
700
DP600
600
Usidur360
500
(MPa)
400
Conventional Stress
300
Usistamp 04
200
100
0
1100
TRIP800
0
5
10
15
20
25
30
35
40
1000
DP750
Elongation
900
DP600
800
TS
700
Dir.
Yp0,2
El()
Ag()
rd
r
delta r
nd
n
Usidur360
600
T
519
840
26,3
21,0
1,18
1,01
0,07
0,217
0,221
Usiphor280
500
L
478
830
28,3
22,5
0,90
0,228
400
D
508
834
25,5
21,1
0,97
0,221
Rational Stress (MPa)
Usistamp 04
300
200

100
0
0
0,05
0,1
0,15
0,2
0,25
Rational Strain
19

• Influence of 10 prestrain on Usiphase D600 GA
  Fatigue Resistance

Max Stress (Mpa)
Mechanical Characteristics YS 379 MPa TS
630 MPa t 1,95 mm
600
10 Prestrain
550
500
Alternating Tension Rs 0,1
As delivered
450
Fatigue Results
400
350
6
State
s
5.10
cycles
d
Delivery
455 MPa
300
Prestrain 10
541 MPa
100000
1000000
10000000
Number of cycles
20
Problems to consider
Springback Control
Others - avoid wrinkles formation then difficult
to eliminate - Stamping Presses Capacity -
tools coatings - tools pollution by steel
coatings due to heat - welding adjustments
7
-j/ep.1.2 - R 3 - R 2 -j/ep.1 - R 3 -
R 2 -j/ep.0.95 - R 3 - R 2
6
5
4
3
Springback Angle
2
1
0
300
400
500
600
700
800
TS (MPa)
Decrease with - die radius - punch-die
clearance - blankholder force increase
21
(No Transcript)
22
TYPICAL HOT-STAMPING ( direct process)
Heating 5-10 min
880-950 C Austenitisation alloying reaction on
coating

• First stage heating in furnace

23
Hot stamping what is it ?
TYPICAL HOT-STAMPING ( direct process)
Heating 5-10 min
880-950 C Austenitisation alloying reaction on
coating

• First stage heating in furnace

• Second stage hot forming (600-800C) and ...

24
Hot stamping what is it ?
TYPICAL HOT-STAMPING ( direct process)

• First stage heating in furnace

• Second stage hot forming and ...

• Third stage quenching between the dies

25
HOT STAMPING ( direct process )
Fast transfer time between furnace and
dies Stamping with high speed and low pressures
(200 to 500 T) Stamping is carried out between
800C and 600C
20C
At high temperature, USIBOR 1500 P has very high
elongations (gt 50)
400C
600C
800C
26
TYPICAL HOT-STAMPING LINE ( direct process )
27
USIBOR 1500 P APPLICATIONS
Hood reinforcement
A-pillar reinforcement
Door beams
B-pillar reinforcement
Bumper beam
Side rail member
28
Renault Laguna II
USIBOR 1500 P
FRONT BUMPER BEAM OF THE LAGUNA II USIBOR 1500
PRECOATED IN 2 mm THICKNESS (PHOTO WITH THE KIND
PERMISSION OF RENAULT SA)
29
Citroën C5
USIBOR 1500 P
A PILLAR RENFORCEMENT OF THE CITROËN C5 USIBOR
1500 PRECOATED IN 1.17 mm THICKNESS (PHOTO WITH
THE KIND PERMISSION OF PSA PEUGEOT CITROËN)
30
WELDED BLANKS MARKET IN EUROPE
31
Multi Thickness Blanks

• MTB are Steel Solutions which allow
• Weight Saving
• Reduction of the number of parts
• Reduction of the manufacturing time for the
  function
• Reduction of functionnal cost on the Global
  chain
• And / Or an increase of in-service performance.

32
TYPICAL INDUSTRIAL APPLICATIONS

• Closure inners(hinges and latch
• reinforcements)
• Shock tower
• Reinforcements of pillars,
• side rails,
• front and rear rails
• and transverse members
• Local reinforcements
• of floor panel
• ...

33
CASE OF A DOOR INNER

• Suppresssion of the
• post-assembly hinges
• Reinforcement integrated
• Better stiffness
• Cost reduction
• Weight reduction

Door Inner 2,3 Kg of weight reduction
34
Laser Tailored Blank
Patchwork
35
TWB contribute to mass of vehicle reduction
Body side 8 kg of weight saving (25)
Rail 2,4 Kg of weight saving (18,5)
B. Pillar 2.5 kg of Weight Saving (14)
Suspension support 1,2 Kg of weight saving
(33)
Door Inner 2,3 Kg of weight saving (17)