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 Advanced high strength steels

Description

The Complex Phase family of steels supplements ArcelorMittal's AHSS (advanced 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)

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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

  Euronorms VDA 239-100

Complex Phase 600 HCT600C (+ZE) Complex Phase 800 Y500

Complex Phase 800 Y600 HCT780C (+ZE, +Z) CR570Y780T-CP (-UNC,-EG,-GI) Complex Phase 1000

Complex Phase 1000 SF 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) HR660Y760T-CP (-UNC,-GI) Complex Phase 1000 HDT950C (+Z)

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  Euronorms Uncoated (EN 10338 :2015): Steel grade nameElectrogalvanized (EN 10338 :2015 + EN 10152 :2017): Steel grade name +ZEGalvannealed (EN 10346 :2015): Steel grade name +ZFExtragal® (EN 10346 :2015): Steel grade name +Z

VDA 239-100 Uncoated: Steel grade name-UNCElectrogalvanized: Steel grade name-EGGalvannealed: Steel grade name-GAExtragal®: 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 propertiesGuaranteed values for ISO 20x80 specimen of uncoated sheet in the strip center at ambient temperatureST -Transverse direction (perpendicular to the rolling direction) / SL -Rolling direction

  YS (MPa) UTS (MPa)ef (%)

L0 = 80 mmth < 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

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Microstructure of hot rolled Complex Phase 1000

Chemical composition (%)

  C Mn Si  Max Max 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 Worldwide availability

  Uncoated Electrogalvanized

  EUR NAM SAM RSA CHI EUR NAM SAM RSA CHI

Complex Phase 600                

Complex Phase 800 Y500                

Complex Phase 800 Y600                

Complex Phase 1000 SF                    

Complex Phase 1000 SF /Complex Phase 1000 Y800

               

Complex Phase 750 /MP 800

             

Complex Phase 800 /M 800 HY

             

Complex Phase 1000 /MP 1000

             

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  Extragal® Jetgal®

  EUR NAM SAM RSA CHI EUR NAM SAM RSA CHI

Complex Phase 600                  

Complex Phase 800 Y500                  

Complex Phase 800 Y600                

Complex Phase 1000 SF                    

Complex Phase 1000 SF /Complex Phase 1000 Y800

               

Complex Phase 750 /MP 800

                 

Complex Phase 800 /M 800 HY

                 

Complex Phase 1000 /MP 1000

                 

 Hot rolled      Cold rolled

Available in non-visible part quality Undergoing customer testing Under development Available in visible and non-visible part quality (Z)

EUR : Europe Region -NAM : North America Region -SAM : South America Region -RSA : South Africa Region -CHI : China

X  Product available /O Product under developmentSF (Stretch Flanging): grade specially developed for improved stretch flangeability.Please consult us about products under development.

Recommendations for use and secondary processing

FormingAlthough 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.

Forming limit curves for Complex Phase steels:

Cold rolled in 1.5 mm thickness

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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.

View of hole expansion in grades CR-CP 1000 and CR-CP 1000 SF in 1.5 mm thickness.The CP 1000 SF 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.

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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 weldingThe 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)

Nugget diameter (mm)

Pure tensile (kN)

Weld diameter (mm)

Tensile-shear (kN)

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

Complex Phase 1000 Extragal® 3 9.8 31.1 9.4 51.1

  Hot rolled      Cold rolled

Laser weldingLaser 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

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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.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: 04-06-2018

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