Complex Phase steels

Automotive Worldwide
Complex Phase steels
Extract from the product catalogue -European edition
Note: Information contained in this catalogue is subject to change.
Please contact our sales team whenever you place an order to ensure that your requirements are fully met.
Please contact us if you have a specific requirement that is not included in the range of products and services covered by this catalogue.
We are also reachable by the e-mail address automotive.request@arcelormittal.com.
We are also reachable by the e-mail address automotive.request@arcelormittal.com.
Complex Phase steels
Very high strength steels
Description
The Complex Phase family of steels supplements ArcelorMittal's VHSS (very high strength steel) product range. These steels are cold
formed to make lightweight structural elements. A number of automotive parts, such as sills and door reinforcements, have simple shapes
and the steel is therefore only slightly deformed. For this reason, ArcelorMittal has added the Complex Phase family of steels to its range.
These steels offer high as-delivered yield strength and good bendability and stretch flangeability.
Applications
Given their high energy absorption capacity and fatigue strength, these grades are particularly well suited for automotive safety components
requiring good impact strength and for suspension system components.
Seat flange in Complex Phase 600 (thickness: 1.5 mm)
Door bar in Complex Phase 1000 (thickness: 2 mm)
Tunnel stiffener in Complex Phase 800 (thickness: 1.6 mm)
2
Fender beam in Complex Phase 1000 (roll-formed)
Fender beam in Complex Phase 1000 (roll-formed)
Suspension arm in Complex Phase 800 (thickness: 3.1 mm)
Designation and standard
Complex Phase 600
Euronorms
VDA 239-100
HCT600C (+ZE)
Complex Phase 800 Y500
Complex Phase 800 Y600
HCT780C (+ZE, +Z)
CR570Y780T-CP (-UNC,-EG,-GI)
Complex Phase 1000
HCT980C (+ZE)
CR780Y980T-CP (-UNC,-EG)
Complex Phase 1000 Y800
HCT980C (+Z)
CR780Y980T-CP (-GI)
Complex Phase 750
HDT750C (+Z)
Complex Phase 800 SF
HDT780C (+Z)
Complex Phase 1000
HDT950C (+Z)
Complex Phase 1000 SF
3
HR660Y760T-CP (-UNC,-GI)
Euronorms
Uncoated (EN 10338 :2015): Steel grade name
Electrogalvanized (EN 10338 :2015 + EN 10152 :2009): Steel grade name +ZE
Galvannealed (EN 10346 :2015): Steel grade name +ZF
Extragal® (EN 10346 :2015): Steel grade name +Z
VDA 239-100
Uncoated: Steel grade name-UNC
Electrogalvanized: Steel grade name-EG
Galvannealed: Steel grade name-GA
Extragal®: Steel grade name-GI
Hot rolled Cold rolled
SF (Stretch Flanging): grade specially developed for improved stretch flangeability.
While the ArcelorMittal grades conform perfectly well to the indicated EN standards, ArcelorMittal grades generally offer tighter mechanical
properties (see table below).
The above indicative table summarizes the European and VDA standards corresponding to the ArcelorMittal product range.
Technical characteristics
Mechanical properties
Guaranteed values for ISO 20x80 specimen of uncoated sheet in the strip center at ambient temperature
ST -Transverse direction (perpendicular to the rolling direction) / SL -Rolling direction
YS (MPa)
UTS (MPa)
ef (%)
L0 = 80 mm
th < 3 mm
Direction
Complex Phase 600*
360 -440
600 -700
≥ 19
SL
Complex Phase 800 Y500
500 -650
780 -900
≥ 13
SL
Complex Phase 800 Y600
600 -700
780 -900
≥ 10
SL
Complex Phase 1000
700 -850
980 -1200
≥8
SL
Complex Phase 1000 SF
780 -950
980 -1200
≥7
SL
Complex Phase 1000
Y800
800 -950
980 -1130
≥6
SL
Complex Phase 750
620 -750
≥ 750
≥ 10
SL
Complex Phase 800
680 -830
≥ 780
≥ 10
ST
Complex Phase 1000*
800 -950
≥ 950
≥ 10
SL
Hot rolled Cold rolled
SF (Stretch Flanging): grade specially developed for improved stretch flangeability.
* The guarantees for this grade are subject to change.
Microstructure of hot rolled Complex Phase 800
4
Microstructure of hot rolled Complex Phase 1000
Chemical composition (%)
C
Max
Mn
Max
Si
Max
Complex Phase 600
0,10
1,60
0,40
Complex Phase 800 Y500
0,17
2,20
0,60
Complex Phase 800 Y600
0,17
2,20
0,60
Complex Phase 1000
0,18
2,40
0,60
Complex Phase 1000 SF
0,18
2,40
0,60
Complex Phase 1000 Y800
0,20
2,70
0,80
Complex Phase 750
0,25
1,40
0,40
Complex Phase 800
0,10
2,00
0,25
Complex Phase 1000
0,14
1,70
0,25
Hot rolled Cold rolled
SF (Stretch Flanging): grade specially developed for improved stretch flangeability.
Available coatings and surface conditions
Uncoated
Electrogalvanized
Complex Phase 600
X
X
Extragal®
Complex Phase 800 Y500
X
X
Complex Phase 800 Y600
X
X
X
Complex Phase 1000
X
X
O
Complex Phase 1000 SF
X
X
O
O
X
Complex Phase 1000 Y800
Complex Phase 750
X
X
Complex Phase 800
X
X
Complex Phase 1000
O
X
Hot rolled Cold rolled
X Product available /O Product under development
SF (Stretch Flanging): grade specially developed for improved stretch flangeability.
Please consult us about products under development.
Recommendations for use and secondary processing
Forming
Although their ultimate elongation is lower than that of DP and TRIP steels, Complex Phase steels have good formability for their high
strength level.
Forming limit curves can be used to define maximum strains without necking for different deformation paths.
5
Forming limit curves can be used to define maximum strains without necking for different deformation paths.
Forming limit curves for Complex Phase steels:
Cold rolled in 1.5 mm thickness
Hot rolled in 3 mm thickness
In addition, Complex Phase steels exhibit good roll-forming, bending and hole expansion behavior.
The graph below illustrates hole expansion behavior according to the ISO 16630 standard for a number of Dual Phase and Complex Phase
steels with UTS=1000 MPa. The Complex Phase family -and especially the Complex Phase Stretch Flangeable (SF) product, which was
specially designed for exceptional stretch flangeability -has higher hole expansion values.
6
View of hole expansion in grades CR-CP 1000 and CR-CP
1000 SF in 1.5 mm thickness.
The CP 1000 SP achieves a much higher hole expansion
value.
The table below shows typical minimum bending radius values for Complex Phase steels in 1.5 mm thickness.
Rolling direction
Transverse direction
Complex Phase 600
0
0
Complex Phase 800 Y500
0
0,5
Complex Phase 800 Y600
0,5
0,5
Complex Phase 1000
0,5
1
Complex Phase 1000 SF
0,5
1
Hot rolled Cold rolled
Rolling direction
Transverse direction
Bending method: 90° flanging
For more information about the forming of Complex Phase steels in special thicknesses and with special coatings, please consult us.
Welding
Resistance spot welding
The Complex Phase range of steels has very good resistance spot weldability. The welding range, determined according to the ISO 18278-2
standard, is quite wide. The table below shows examples (indicative) of spot welding characteristics for Complex Phase matching joints,
determined according to the ISO 18278-2 standards.
7
The Complex Phase range of steels has very good resistance spot weldability. The welding range, determined according to the ISO 18278-2
standard, is quite wide. The table below shows examples (indicative) of spot welding characteristics for Complex Phase matching joints,
determined according to the ISO 18278-2 standards.
Coating
Thickness
(mm)
Complex Phase
600
-
1.5
8.4
15.1
9
21.2
Complex Phase
800
-
1.5
8.7
13.2
7.6
24.2
Complex Phase
1000
-
1.6
7.2
9.9
6.9
28.1
Complex Phase
800
-
3
11.3
41.4
9.6
48.2
3
9.8
31.1
9.4
51.1
Complex Phase
Extragal®
1000
Hot rolled Cold rolled
Nugget diameter Pure tensile Weld diameter Tensile-shear
(mm)
(kN)
(mm)
(kN)
Laser welding
Laser welding tests have revealed no particular difficulties.
ArcelorMittal can provide technical assistance in adjusting the welding parameters for all steels in the Complex Phase range.
Fatigue
Complex Phase steels exhibit good fatigue properties and can be used in suspension system parts such as suspension arms. The table
below gives examples of Wöhler curves for a variety of Complex Phase steels. They are expressed as stress amplitude versus cycles to
failure and are obtained with a stress ratio of R = 0.1 and repeated tensile loading.
Wöhler or SN curves for Complex Phase steels (R=0.1)
The graph below shows the low cycle or EN curves for the same steels. These are expressed as strain amplitude versus number of reversals
(one cycle equals two reversals). Other high and low cycle fatigue data are available on request.
Low cycle or EN curves for Complex Phase steels (R=-1)
ArcelorMittal can provide a full database on the fatigue performance of Complex Phase steels.
Impact strength
As a result of their very high YS and UTS values, Complex Phase steels are particularly well suited for anti-intrusion parts.
8
As a result of their very high YS and UTS values, Complex Phase steels are particularly well suited for anti-intrusion parts.
Complex Phase steels have been characterized in the 3-point bending flex test using top hat cross-section specimens impacted at 30 kph.
The tests showed very good behavior of these steels.
Mass savings potential compared to an HSLA 380 steel
(reference)
© ArcelorMittal | Last update: 08-01-2016
9