festo

Automotive Worldwide

Extract from the product catalogue

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 [email protected].

Index

ArcelorMittal 2Development Trends 3Product Safety and Toxicology 5Life Cycle Analysis and Recycling 7Product Definition 9Product Selection Guide 17Equivalent Standards Tables 20Worldwide product availability 24Dual Phase steels 25TRIP (TRansformation Induced Plasticity) steels 32Complex Phase steels 37Hot rolled ferrite-bainite steels 45Steels for hot stamping -Usibor 50Steels for cold stamping -Fortiform 58MartINsite steels 63High strength low alloy (HSLA) steels for cold forming 68Bake hardening steels 73High strength IF steels 78Solid solution steels 81High formability steels for drawing 84Extragal double-sided pure zinc galvanized steels 90Ultragal 92Galvannealed zinc-iron alloy coated steels 94Steels coated with galfan zinc-aluminium alloy 96Electrogalvanized sheet coated on one or both sides 99Surface treatments 101Thin Organic Coatings (TOCs) 103Steels coated with Alusi, an aluminum-silicon alloy: general points 106Steels coated with Alusi aluminum-silicon alloy: specific applications 108iCARe: ArcelorMittals range of electrical steels for automotive 113iCARe Save 117iCARe Torque 119iCARe Speed 121Coatings for iCARe 123Advanced technical support for iCARe 125A range of technical services to support product selection 127Finishing: Auto Processing 128Multi-thickness laser welded blanks: Tailored Blanks 131

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We are also reachable by the e-mail address [email protected].

ArcelorMittal

An unparalleled partner for automotive manufacturers

ArcelorMittal is the world's number one steel company. ArcelorMittal is the leader in all major global markets, including automotive, construction, household appliances and packaging. Supporting our position is a commitment to industry leading R&D and technology.The Group holds sizeable captive supplies of raw materials and operates an extensive distribution network, ensuring sustainability and quality throughout the supply chain. Its industrial presence in 20 countries across Europe, Asia, Africa andAmericagives the Group exposure to all the key steel markets, from mature to emerging, such as the high growth markets inChinaandIndia.

As a supplier of automotive steels, ArcelorMittal is unequaled. The dedicated organization it has put in place to serve automotive manufacturers, sub-contractors and equipment suppliers gives them the benefit of global expertise, state-of-the-art research and development and a comprehensive and internationally available product, solution and service offering.

Within this dedicated organization, separate customer teams are structured to support each customer's worldwide growth while providing local service. Teams are made up of account managers in charge of supporting the customer's strategy and technical experts able to anticipate and facilitate product utilization. The flexibility of this organization enables ArcelorMittal to serve as a co-engineering partner throughout the life of the vehicle, from design through production.

The purpose of ArcelorMittal Research and Development, which has dedicated automotive laboratories in the United States and Europe, is to propose increasingly innovative solutions to automotive manufacturers. Its primary goal is to stay ahead of the curve, anticipating the environmental, safety and cost control issues facing the automotive sector and devising effective and sustainable solutions to address them. It develops breakthrough product and processing technologies while maintaining a constant focus on cost control.

ArcelorMittal automotive steels have outstanding properties in use and cover the full range of metallurgical families, coatings and surface treatments. ArcelorMittal has a recognized global technological edge in galvanized steels for exposed parts and coated steels for hot stamping. Striking an optimum balance between mass savings and formability, its wide range of products is available throughout the world and is supplemented by services and solutions provided by the Group's international network of wholly-owned and associated processing centers, welded blank production units and drawing partners.

ArcelorMittal offers its customers unrivaled value creation by addressing the ever-changing challenges they face, supporting their expansion and growth and providing them with outstanding products and services.

ArcelorMittal | Last update: 26-12-2012

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Development Trends

The Automotive Worldwide catalogue reflects the major trends in new product development being pursued by the ArcelorMittal group in response to the needs of its automotive sector customers:

Proposals for reducing vehicle weightCost reductionsEnvironmental protection

As world leader, ArcelorMittal is called upon to take the lead in innovation, focusing on breakthrough technologies that will, in some cases, prove indispensable in the future.

Reduction of vehicle weight

We are constantly extending our range of very high strength steels suitable for structural parts. We have, for example, added several grades in the 800 to1200 MPa tensile strength range. These products-hot and cold rolled, coated and uncoated Dual Phase, Complex Phase and martensitic steels-provide many different combinations of weight reduction capacity and formability.

To meet the need for weight reduction in closures, our catalogue now includes a Dual Phase FF 280 DP Extragal adapted to the requirements for visible parts.

Other metallurgical concepts are being studied by our R&D team in our ongoing endeavour to further expand our product range.

Cost reduction

ArcelorMittal offers high-performance solutions with proven capacity for reducing certain process costs. For example, the new surface treatments for zinc coatings-NIT and L-Treatment-improve the robustness of the drawing process. Because of their surface properties, the frequency of equipment cleaning operations (which are crucial, especially for skin parts) can often be reduced.

Ultragal offers new guarantees with respect to waviness and hence to paint appearance in the galvanized range for visible parts. It offers opportunities for synergies with new shorter-and thus more cost-effective-painting processes.

Environmental protection

ArcelorMittal strives to help protect the environment. For example, Chrome VI has been removed from the group's automotive catalogue. Chromating on a metallic coating has been replaced by E-passivation and surface treatments in the weldable thin organic coatings range are now entirely chromium-free.

Breakthrough technology

The increasingly competitive and global automotive market calls for the development of top-performance products. The quest for combinations of different properties and the need for savings will increasingly require simultaneous product and process development. ArcelorMittal devotes significant resources to the search for breakthrough technologies. A typical example is the emergence of vacuum PVD (Physical Vapour Deposition). New prospects for breakthrough product development have opened up as a result of this technology, which exists in other industries but has never before been applied in a continuous steelmaking process.

The first of these products will probably be the ZEMg coating, obtained by vacuum deposition. The ZEMg PVD coating's capacity for corrosion protection and its surface quality recommend it for many automotive industry applications, for both visible and non-visible parts.These ZEMg PVD coatings have been specially developed to increase corrosion protection in hollow parts and abutments of adjoining parts. They can help reduce the need for additional protective measures such as wax and mastics. They can also improve protection in hollow areas taht are difficult to protect by cataphoresis and can considerably reduce design costs. The main applications are closures, body sides,

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These ZEMg PVD coatings have been specially developed to increase corrosion protection in hollow parts and abutments of adjoining parts. They can help reduce the need for additional protective measures such as wax and mastics. They can also improve protection in hollow areas taht are difficult to protect by cataphoresis and can considerably reduce design costs. The main applications are closures, body sides, underbodies, shock absorbers and all hollow beams in vehicles. These products are aimed at meeting the needs of car body manufacturers with respect to reducting the cost of anti-corrosion guarantees.

Surface appearance of ZEMg PVD coating (Scanning electron micrograph)

Cross-sectional view of ZEMg PVD coating


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Product Safety and Toxicology

Compliance of steels with EoL Directive 2000/53/EC and with automotive industry requirements

Directive 2000/53/EC requires that vehicles placed on the market after 1 July 2003 contain no lead, cadmium, mercury or hexavalent chromium, other than in the cases listed in its Annex 2.

It also requires the identification of other dangerous substances (as defined in Directive 67/548/EEC1 and Regulation (EC) No. 1272/2008*

and Regulation (EC) No. 1272/2008**)that may be used in the manufacture of vehicles. The amendment of Annex 2 of the Directive, published on 20 September 2005 (Council Decision 2005/673/EC), set 1 July 2007 as the date for a comprehensive ban on the use of hexavalent chromium.

In addition, tolerance thresholds were set for these substances:0.1% (1.000 ppm) for lead, mercury and hexavalent chromium0.01% (100 ppm) for cadmium.

Consequently, there is a twofold requirement:Guarantee of compliance of the steel with the Directive, with provision of information on any use of prohibited substances or metals in our products and timetable for implementation of the heavy metal prohibition in the products involved;Provision of information on the composition of our steels, in particular by reporting such information in databases such as IMDS.

* Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances. The classification of dangerous substances can be accessed via http://ecb.jrc.it/classification-labelling/** Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on classification, labeling and packaging of substances and mixtures, amending and repealing Directives 67/548/EEC and 1999/45/EC, and amending Regulation (EC) No 1907/2006

Characteristics of steels supplied to the automotive sector and their compliance with regulations

Composition of steelsThe steels supplied to the automotive sector are often complex, multi-layer products, made up of a substrate with a zinc and/or aluminum based alloy coating, with one or more subsequent surface treatments.

SubstrateThe chemical composition of steel varies from one grade to another. Generally the total concentration of alloying elements does not exceed 3%. The maximum concentration per element may be up to 3% (certain VHS steels contain more than 2% manganese, for example). The most frequently used alloying elements are carbon, manganese, silicon, phosphorous, sulphur, niobium, aluminum, boron, chromium, vanadium, molybdenum and titanium.

Trace lead in steel substrates is not due to deliberate additions during production, but rather to the fact that current processes do not fully eliminate trace elements from raw materials and recycled materials.

Metal coatingsThese coatings are obtained either by continuous hot-dip galvanization or by electrodeposition.

Trace lead and cadmium in coatings (dissolved in the metal lattice) are not due to deliberate additions during production, but rather to the fact that current processes do not fully eliminate trace elements from raw materials and recycled materials.

The sum of lead (Pb) and cadmium (Cd) content in spangle-free coating is less than 100 ppm and mercury (Hg) is not detectable.

Surface treatments:

PassivationArcelorMittal has introduced Cr(VI)-free passivation (E-Passivation), in line with legislation.

PhosphatingThis treatment (42% phosphate, 35% Zn, 5% Mn, 1% Ni) complies with regulations.

Thin organic coatings (TOCs)ArcelorMittal now offers a range of thin organic coatings over hexavalent chromium-free pre-treatment.

Development of environmentally-friendly products

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Development of environmentally-friendly products

ArcelorMittal has implemented a Cr(VI)-free substitution programme, offering Cr(VI)-free solutions for its entire range of products, including sandwich sheet, in accordance with the timetable set by the Directive and/or vehicle manufacturers' decisions.

Communication of information relating to the composition of steel products

Since 2002, the composition of steels supplied to the automotive sector has been available in the IMDS data base.

ArcelorMittal's steels are reported under their commercial name, with a layer by layer description and ID number.

ArcelorMittal's identification number in IMDS is 5502.

We also work with manufacturers who have not joined the IMDS system.

Certification and reporting of dangerous substances

The ArcelorMittal Technology -Health and Safety -Product Safety Department is responsible for the certification procedure.

The risks that might arise during secondary processing of steels are set out in the Safety Data Sheets (SDSs), which may be downloaded from www.arcelormittal.com/fce website under Products & Services > MSDS (Material Safety Data Sheets)'.

Compliance with the REACH Regulation EC 1907/2006

ArcelorMittal is implementing the various aspects of the REACH Regulation according to the regulatory timeframe. In particular, we are making every effort to ensure that the use of our products by our clients is correctly assessed and that all substances present in the products delivered to our clients have been properly registered. Steel coils, slit bands, sheets, blanks and their derivatives are to be considered as articles in the sense of the REACH reglementation. The selection process of substances to be included in the Candidate List of Substances of Very High Concern or in REACH Annex XIV is carefully monitored. We are committed to informing our clients about the presence of any such substances in our products, as provided for in this Regulation. Our Safety Data Sheets have been adapted to the new requirements laid down by REACH and the new CLP (Classification Labelling and Packaging) directive. Further updates may be made as additional information becomes available.

If you have any questions on product safety and toxicology, please ask your usual contact or send an e-mail to: [email protected].


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Life Cycle Analysis and Recycling

The environment a priority focus from the R&D stage onward

Protecting the environment is a key challenge of our time and as the world's leading steel company, ArcelorMittal is committed to helping develop sustainable solutions. The Group's research centers have set up dedicated Life Cycle Analysis (LCA) and recycling units to assess the impact of new products on the environment at the design stage (by means of LCA) and at end-of-life recovery and disposal (by validating their recyclability).

Life Cycle Analysis

This standardized (ISO 14040) method is used to determine the potential impact of a product on the environment throughout its entire life cycle, i.e. from the extraction of the raw materials needed to produce it (ore, oil, etc.) to its production, utilization and end-of-life disposal (recycling, incineration, etc.).The entire life cycle of steel must be considered in the automotive sector since:

the utilization phase accounts for some 80% of a vehicle's overall environmental impact;steel often has an impact that is far smaller than that of its competitors in the production phase;steel's recyclability is a major advantage in end-of-life vehicle regulations.

An LCA study is carried out in four phases:Definition of objectives and of the system studied: observation of the life cycle in order to model it and definition of the functional unit (quantity of product studied = 1 m2 of roofing, 100 beverage cans, vehicle traveling 200.000 km, etc.);

1.

Inventory of flows: list of all the inputs and outputs of the system (quantity of each material needed, emissions, etc.);2. Assessment of impacts: use of inventory data to calculate environmental impact in terms of: global warming, natural resources, acidification, etc.;

3.

Interpretation: proposal of alternative production processes to reduce impact. Comparison of different products to support the choice of the product that best protects the environment.

4.

ArcelorMittal and a variety of consortia have carried out studies that have demonstrated the competitive advantages of steel in this area.

End-of-life vehicle recycling

Directive 2000/53/EC of the European Parliament and the Council of 18 September 2000 on end-of-life vehicles was drawn up to limit or prohibit the presence in vehicles of dangerous substances such as lead, cadmium, chromium IV and mercury, in order to reduce the environmental impact of vehicles throughout their lives. It also defines target recycling and waste-to-energy rates with the goal of reducing as far as possible the ultimate waste from of end-of-life vehicles that is landfilled. In 2006, the target was recycling of at least 80% of materials in addition to a maximum 5% waste-to-energy rate to ensure that a maximum of 15% of the average mass of end-of-life vehicles is landfilled. In 2015, these objectives will increase to 85% materials recycling, 10% waste-to-energy and only 5% landfilled.A large number of vehicle shredding and shredded scrap characterization tests have shown that the ferrous fraction of vehicles is both 100% recyclable and 100% recycled. To ensure that this recycling is sustainable, the ArcelorMittal Group undertakes to verify that all new steels developed for automotive production are easy to recover and recycle. In this spirit, a research team at the ArcelorMittal Research Center in Maizires-les-Metz has developed a methodology making it possible for compliance with the specifications of the European Directive described above to be validated at the time new steels are developed (see diagram below).In partnership with professional scrap processors, the ArcelorMittal Recycling R&D team offers solutions for easily recovering the ferrous fraction generated by their processes, including, importantly, non-magnetic steels. The new steels offered by ArcelorMittal are also subjected to the conventional treatment applied to end-of-life capital goods in which they are used. For example, shredding and sorting tests are carried out in industrial facilities and the scrap recovered is then melted in pilot furnaces so as to determine its meltability and verify that scrap melting does not impact the environment.

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The ArcelorMittal Group is thus able to provide its customers with a guarantee of sustainable recycling of all the steels offered.

Flowchart -Compliance of new steels with Directive 2000/53/EC

Steel is an environmentally-friendly material in use and is virtually infinitely recyclable.


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Product Definition

Major metallurgical families and characterization

ArcelorMittal's range of steels for the automotive sector comprises all the main metallurgical families:Steels for drawing: aluminum killed and IF (Interstitial Free);High-strength steels: high yield strength steels, rephosphorized steels, high strength IF steels, isotropic and bake hardening steels;Very high strength multiphase steels: Dual Phase, TRIP, ferrite-bainite, Complex Phase steels.

The mechanical properties of these steels are the result of a combination of parameters that are defined throughout the steel manufacturing process. The two main parameters are:

Chemical composition;Thermo-mechanical process.

Mechanical propertiesTo obtain the required mechanical properties, the steelmaker devises a range of strength/formability combinations suitable for the uses to which products are to be put in the automobile.A number of hardening processes are available. They can be employed alone or in combination:

Steel hardening mechanism

To activate and control these processes, the steelmaker varies:

a) Chemical composition

The composition of the alloy lends the steel its mechanical strength. Iron from the blast furnace, the first stage in the steel production process, is uniform for all products.In the following process stage, alloying elements are added to or removed from the iron. This stage determines the main families of steel, from the strongest to the most formable. The proportion of carbon plays a crucial role in this determination, since it is the main hardening element added to iron. Other elements such as manganese, silicon and phosphorous are also used to adjust the strength of the steel. More selectively, further alloying elements such as titanium, niobium and vanadium can be added to lend specific hardness properties to the steel. These are called micro-alloyed steels, since these elements have an effect even when added in very small quantities compared to the other alloying elements.In multiphase steels (Dual Phase, TRIP, Complex Phase...) it may be necessary to add chromium and molybdenum to obtain hard phases.Nitrogen and carbon are chemical elements of small atomic size compared to iron. They are called interstitial elements because they are easily positioned within the iron crystal lattice (positions 2 and 3 in the figure below: positions 4 and 5 are occupied by substitution elements such as Mn, Si, etc., and position 1 is a vacancy). Placed in the interstices of the crystal lattice, they harden the crystal as a whole by preventing the atomic planes from sliding against each other. The quantity of interstitial elements in steel determines its mechanical properties. Carbon content is adjusted primarily by blowing oxygen through the molten metal and can be further lowered by vacuum treatment.There are two possible methods for removing carbides and nitrides, i.e. for inducing the precipitation of residual carbon and nitrogen atoms contained in compounds too voluminous to occupy interstitial positions. One-the method used for ordinary and high strength steels-consists in adding aluminum (in this case the steels are said to be "aluminum killed"). The other consists in adding titanium (these steels are then said

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There are two possible methods for removing carbides and nitrides, i.e. for inducing the precipitation of residual carbon and nitrogen atoms contained in compounds too voluminous to occupy interstitial positions. One-the method used for ordinary and high strength steels-consists in adding aluminum (in this case the steels are said to be "aluminum killed"). The other consists in adding titanium (these steels are then said to be "titanium killed"). The second method is the more efficient in reducing total interstitial nitrogen and carbon. This method is used to produce "Interstitial Free" (IF) type mild steels.

Various positions that alloying elements can occupy in the iron crystal lattice

b) Thermo-mechanical process

The grain structure of steel influences its mechanical behavior at two levels:Microscopically, through alignment irregularities (dislocations) and interstitial or substitutional alloying elements within each grain, which is itself a single crystal of iron;More macroscopically, through the shape (elongated or equi-axed) and size of the grains.

For a given chemical composition, these characteristics of a steel are related to the thermo-mechanical cycles it undergoes throughout the manufacturing process:

Solidification in slab form;Hot rolling;Cold rolling;Annealing;Skin-pass.

Rolling temperatures, cooling speeds, coiling temperatures, thickness reduction rates in the cold rolling mill, annealing cycles and skin-pass parameters are all varied in order to adjust the structure of the steel and hence the product's final properties.

Steel grain structure

Tensile testSteel is characterized by the mechanical properties of products sold both in the cold rolled (thicknesses below 3.0 mm) and the hot rolled (currently, thicknesses higher than 1.8 mm) state. These properties reflect the product's propensity for secondary processing and for forming by means of drawing, bending, hydro-forming, etc. The method most commonly used to determine the mechanical properties of materials is the tensile test.It has two advantages:

It is easy, rapid and standardized.The resulting stress-strain curve provides a large amount of precise information.

The test consists in gradually elongating a specimen of the grade to be characterized. A uniaxial load is applied to the specimen in the rolling or transverse direction. The load needed to deform the specimen to failure and the elongation of the specimen are recorded simultaneously. These values are used to plot stress (load divided by the initial cross-section of the specimen) against strain (expressed as percent

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The test consists in gradually elongating a specimen of the grade to be characterized. A uniaxial load is applied to the specimen in the rolling or transverse direction. The load needed to deform the specimen to failure and the elongation of the specimen are recorded simultaneously. These values are used to plot stress (load divided by the initial cross-section of the specimen) against strain (expressed as percent elongation of the initial gage L0).This is the stress-strain curve, shown in the figure opposite. This uniaxial test is spelled out precisely in the EN 10002-1 standard and elsewhere. The importance of specimen preparation (machining), especially for high strength steels, should be borne in mind.

Shape of the stress-strain specimen

Configuration of the tensile test machine

Shape of the stress-strain curve

RemarksTest specimen dimensions:1. The dimension of tensile test specimens varies according to the thickness of the product tested:a. thickness 3 mm: width 20 mm and length 80 mm;b. thickness > 3 mm: width 30 mm and length 5.65 S0. where S0 = width x thickness. Standard dimensions in Europe (EN standards).2. Specimen dimensions also vary from one country to another:a. Japan (JIS standard): width 25 mm and length 50 mm;b. USA (ASTM standard): width 12.5 mm and length 50 mm.

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b. USA (ASTM standard): width 12.5 mm and length 50 mm.Because of these variations in specimen size, the mechanical properties measured are not directly comparable. However, well-established conversions exist between the different standards.

JIS -EN -ISO elongation value correlations

These conversions are indicative. Our technical department can provide further information as required.

Tensile test directionAll parameters derived from the tensile test reflect the properties of the steel in a specific direction: that of the tensile test. These values depend on the direction in which the sample was taken with respect to the direction in which the thin sheet was rolled.When indicating the mechanical properties of steel, the sampling direction with respect to the rolling direction must always be specified:

Rolling direction RD (indicated by 0);Transverse direction TD (indicated by 90);Oblique direction (indicated by 45).

Main mechanical properties

The tensile test measures the following parameters, which characterize the material:

a) Yield stress: YS

Point A on the stress-strain curve. It represents the load at which the elastic domain, in which deformation is reversible, ends and the plastic domain, in which deformation is irreversible, begins.

Typically, there are two types of transition:

The transition between the elastic and plastic domains shows a maximum followed by a sudden drop in yield stress and a plateau. A distinction is made between upper yield stress UYS, corresponding to the peak, and lower yield stress LYS, corresponding to the plateau. The length of the plateau is the yield point elongation es.The transition is gradual. Yield stress is then defined conventionally. It is measured for 0.2% elongation and termed 0.2% proof stress (0.2% PS). The term YS will be used to cover both types in this document.

Definition of yield stress and plateau

b) Ultimate tensile stress (or tensile strength or mechanical strength): UTS

Point B on the stress-strain curve. This is the maximum load reached during the tensile test.

Beyond this point, deformation begins to concentrate locally in a phenomenon called "necking", which explains the drop in the load required for further deformation beyond Point B.

c) Fracture elongation: ef%

This is the residual elongation after failure of the specimen at point C on the stress-strain curve.

d) Strain hardening coefficient: n

In the tensile test, loads are measured with respect to the initial cross-section of the specimen. True stress and true strain are determined by calculating the load with respect to the instantaneous cross section, using the law of conservation of mass/matter.The resulting plot of = f() is called the true stress-strain curve. This curve can be described by the Holloman law: = k.n, in which n is called the strain hardening coefficient. It describes the propensity of steel to harden during deformation in the plastic domain (the higher the value of n, the more rapidly the steel hardens), to deform in the expansion mode and to redistribute strains.

e) Anisotropy coefficient: r

The anisotropy coefficient measures the tendency of the steel to resist thinning during the tensile test. It expresses the ratio between specimen width deformation and specimen thickness deformation and thus reflects the steel's ability to undergo severe deep drawing strains.

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The values of r are usually on the order of 1 for hot-rolled sheet but can go up to nearly 3 for steels with the highest drawability.

f) Bake hardening

Bake hardening describes the steel's ability to harden during paint baking; this is used to increase the yield strength of the finished part.

These steels thus combine good drawability with good dent resistance after paint curing (YS value higher than in the initial blank) and good plastic deformation resistance in the finished part.Bake hardening is determined by measuring the increase in YS following heat treatment at 170C for 20 minutes, simulating paint curing conditions, after 2% uniaxial pre-strain (most representative value). This parameter is called BH2.

g) Work hardening

Work hardening describes the increase in yield stress compared to a reference level following plastic deformation. It is directly correlated with the steel's strain hardening coefficient n.

Low-carbon flat steel families

Low-carbon flat steels can be grouped into families according to their mechanical properties, their strength/ductility combination and the metallurgy (chemistry and thermo-mechanical processes) employed in their manufacturing. Within the metallurgical families, classification by YS and UTS range defines grades.

Metallurgical families

Range of ArcelorMittal steels for the automotive sector

Usibor steels for hot forming are not shown. Their mechanical strength is on the order of 1500 MPa after hardening.

Coatings

In the automotive industry, autobody anti-corrosion protection, expressed as the anti-corrosion guarantee, has become a major selling point.

Several protection solutions have been developed and the most widely used can be divided into three groups:

Hot-dip metal coatings applied by immersion in a liquid metal bath (at temperatures up to 700C);Metal coatings applied by electrodeposition (at temperatures slightly above ambient);Thin (0.5 to 6 m) organic coatings applied on a substrate previously protected by electrodeposited or hot dip metal coating and pre-treated to increase corrosion resistance and adhesion of the organic coating.

Various families of coatings exist, depending on deposition process, chemical composition, thickness (or weight per unit area), application on one or both sides and surface appearance requirements.

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Various families of coatings exist, depending on deposition process, chemical composition, thickness (or weight per unit area), application on one or both sides and surface appearance requirements.Coating thickness is measured continuously on coating lines by means of x-ray gauges that scan the full width of the moving strip.

Other types of measurement can be carried out to obtain a point value:Permascope, to determine the difference in product thickness with and without the coating;Chemical measurement, to determine the difference in the weight of a sample with and without the coating (this is the most accurate measurement);Optical microscopy, to determine highly local coating thickness values.

Surface condition

The surface condition of steels has a major impact on their service properties, particularly during the forming and painting processes.

Surface quality is characterized primarily by:Surfacetopography;Lubrication;Chemical treatment.

Surface topographySurface topography describes the surface micro-geometry of the steel sheet. This is essentially a two-dimensional parameter but it is usually characterized by a series of profiles (cross-sections). A profile is measured by means of a roughness tester, generally mechanical, and the profile is recorded by the vertical movements of a stylus placed on the surface. The signal can be broken down into several sinusoidal components with different wavelengths and amplitudes. The shortest wavelengths correspond to roughness and the longest to waviness.

Breakdown of a surface profile: the profile is a superimposed image of roughness, waviness and flatness defect, if any

Roughness:Two parameters are primarily measured:

Roughness, Ra, i.e. the average depth of the surface profile. It generally ranges between 0.5 and 3 m;Peak count, RPc, i.e. the number of peaks that consecutively project beyond a band of given width (generally 0.5 m) centered around the mean profile depth, expressed in number per unit length (n.cm-1).

Increasing surface roughness while holding lubrication constant can help prevent seizing during drawing, especially in the case of uncoated products.

However, any increase in roughness must be assessed in terms of the entire process, with particular attention to surface appearance after painting.

Remark:The calculation of roughness parameters is performed on the basis of a specific length for precise evaluation (at least five times the cut-off length). Depending on the measurement instrument, total length is generally 12.5 mm.The cut-off length is the long wavelength filtering threshold necessary for obtaining measurements representative of local micro-geometry.

Waviness:Profile scanning also includes a measurement of waviness, which is the average value of the amplitudes within the wavelength limits set.Waviness is major factor in appearance after painting (alongside, of course, painting process parameters). It is measured by, for example, the Wa 0.8 parameter.For additional information, please contact our technical support department.

Surface texture controlSurface topography is imprinted on the strip by the roughness of the working rollers.Roughness is transferred in the last stand of the cold rolling mill and during the skin pass operation after annealing or hot-dip galvanizing. Most of the roughness is transferred during the skin pass.ArcelorMittal has developed special expertise in this area and can achieve the best possible combination of drawability and paint appearance.Two main texturing processes are used:

EDT (Electrical Discharge Texturing) produces a stochastic surface texture;

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EDT (Electrical Discharge Texturing) produces a stochastic surface texture;EBT (Electron Beam Texturing) produces a fully controlled displacement of the electron beam, with impingement equally spaced along the axis and circumference of the work rolls.

Examples of roughness profiles (parallel scanning to obtain a 3D image)

Example of surface appearance after skin pass with EDT texture

LubricationLubrication serves two purposes. It:

protects surfaces, both uncoated (red rust) and coated (white rust), against oxidation during storage and handling;reduces friction and the tendency to seize during drawing.

Lubrication consists in depositing oils in a set quantity (ranging between 0.5 and 2.5 g/m2/side).Lubricant suppliers offer a variety of products, from which ArcelorMittal has selected a range corresponding to the various requirements of its customers; certain oils called "prelubes", in particular, spectacularly improve the tribological performance of a given steel at constant texture.ArcelorMittal also offers a range of dry films (drylubes) that can be applied to most coatings and to uncoated steels. These lubricants lend the steel very high friction performance and in most cases eliminate the need to re-oil, even in the most difficult situations. Because they are dry, they also have the advantage of helping to keep the shop floor clean. To develop an appropriate lubrication for an application, full-scale tests should be carried out to investigate forming behavior as well as possible impact on downstream processes (adhesive bonding, de-greasing and surface treatment in particular).

Chemical treatmentsArcelorMittal provides a wide range of chemical post-treatments designed to improve the drawing performance of coated steels:

Specific chemical treatments such as S250 improve the tribological behavior of electrogalvanized products;Pre-phosphating electrogalvanized sheet improves tribological properties, limits particle formation during drawing, increases corrosion protection and facilitates paint adhesion;NIT treatment achieves the tribological performance of pre-phosphating. It is available on electrogalvanized and pure zinc galvanized substrates. It is particularly useful in difficult drawing operations, ensuring uniform friction when the steel has been lightly oiled and limiting particle formation during drawing;

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NIT treatment achieves the tribological performance of pre-phosphating. It is available on electrogalvanized and pure zinc galvanized substrates. It is particularly useful in difficult drawing operations, ensuring uniform friction when the steel has been lightly oiled and limiting particle formation during drawing;L-Treatment, which serves comparable purposes on Galvannealed substrate.

The friction behavior of NIT on galvanized sheet is similar to that of pre-phosphated electrogalvanized sheet

These post-treatments all strengthen the drawing process. They potentially reduce reject/rework rates.They cannot be considered universal solutions. Their use must be examined on a case-by-case basis and they must be discussed with our technical support teams.

Surface appearance after painting

With ongoing improvements in steel substrates and painting techniques, it is now possible to obtain very good painting quality. Nevertheless, a film of paint is never completely flat and it never completely reflects light, as would a perfect mirror. The discrepancy between this ideal and the painted surface can be expressed in terms of distinctness of image (DOI) and gloss. DOI is the ability of the painted sheet to reflect an image distinctly.It is measured, for example, by the DOI (Distinctness of Image) factor. Gloss is thecapacity of the sheet to avoid distortions of the reflected object, often called the orange peel effect.

Painted appearance assessment: typical measurements

The painted appearance quality of a sheet to be used for skin parts is first dependent on painting process parameters-layer thicknesses and application and curing conditions.Once the painting process has been optimized, the best results can be obtained by controlling the topographical parameters of the sheet. The waviness parameter (expressed as Wa 0.8), more than roughness, is crucial in this regard.ArcelorMittal has developed its process for manufacturing coated steels for skin parts to control waviness in the initial blank and limit the recurrence of waviness after drawing.


16


Product Selection Guide

ArcelorMittal offers a wide range of steel grades and coatings to help its automotive sector customers design and produce vehicle bodies and components meeting the requirements of an increasingly demanding market.

Several elements define a steel product:metallurgical grade, often broken down into several qualities, determining the mechanical strength and formability required for the part;coating, to meet corrosion resistance and surface appearance specifications;surface condition, determining friction behavior during forming as well as adhesion properties and post-paint appearance.

This catalogue is thus organized in dedicated technical sheets:metallurgical grades: products are defined according to their metallurgy and their mechanical strength, often involving specific applications,coatings, including hot-dipped and electrodeposited metal and organic coatings,aluminized steels, specific to exhaust systems, fuel tanks and heat shields. These are covered in a separate chapter,composite products such as sound-absorption sheet and thick polymer core sheet.

This catalogue has been designed as a working tool and reflects the range of products and services available from ArcelorMittal at a given point in time. The range is subject to ongoing development and will be expanded in coming years to include new grades offering improved strength-formability combinations and coatings for a wider range of substrates. All product range extensions and product renewals will be directly accessible from the customer's usual technical or sales contact and posted on the ArcelorMittal catalogue website.

The following section explains the approach to be used to identify the ArcelorMittal product which will best suit a given application, system or component. The reader thus has the benefit of the experience ArcelorMittal has built up with its customers in the area of product selection for the main automotive systems.

Choice of steel grade

The choice of a steel grade is generally a compromise between two more or less conflicting objectives:

1. Part performance in service.

The design office calculates the minimum strength (yield and/or tensile strength) level required. These must be guaranteed for each component in order to meet the relevant performance requirements, especially in terms of impact strength (deformation resistance or energy absorption in crash conditions) and durability (fatigue strength).

It should be emphasized that the move to save mass (in order to reduce CO2 emissions) is prompting manufacturers to reduce thickness as much as possible, which in turn means that strength levels need to be increased.

2. Industrial feasibility under economically acceptable conditions, generally at high production rates.

To meet this objective, good ductility, generally expressed as high ultimate elongation, is required.

ArcelorMittal steel grades are therefore ranked in the following tables by strength level.

Recommended products

Specifications

Choice of coatings

Product/coating availability

The final mechanical properties of a steel are determined by all of the mechanical (hot rolling, cold rolling, skin pass, tension leveling, etc,) and thermal (hot rolling, continuous or batch annealing, galvanizing, etc.) treatments that the steel strip undergoes throughout the manufacturing process.

During hot dip coating (zinc or aluminum), the strip passes through a liquid coating bath held at approximately 460C in the case of galvanizing and 680C in the case of aluminizing. For Galvannealed type coatings and organic coatings, a further baking stage is required in order to:

achieve Fe-Zn alliation at between 500 and 550C in the case of Galvannealed,cross-link resins and evaporate solvents at between 150 and 250C in the case of organic coatings.

17

Clearly, the thermo-mechanical processing plan must include the coating phase to ensure that the required final product mechanical properties are achieved. This means that the choice of a steel grade and the choice of coating are linked. The detailed product sheets provided later on in this catalogue give the combinations of grades and coatings that are currently possible.

In the case of thin organic coatings (TOC), the grade/coating/TOC combinations are too complex to be summarized in a simple table and customers are asked to consult us.

Coating properties in service

Apart from the question of availability in the chosen grade (this applies mainly to external body parts), the choice of coating is a compromise between:

1. coating compatibility with the process employed:drawing behaviorinfluence on weldingphosphating aptitude

2. coating characteristics in service:appearance after paintingcorrosion resistance

The tables below give a comparative evaluation of the most common coatings in terms of these criteria:

Extragal Galvannealed Galfan Electrogalvanized Treated electrogalvanized

Drawing behavior + + [] (1) + + + + +Influence on welding [] + + # + + (2)

Aptitude for phosphating [] (3) + # + + +Appearance after painting + + [] (4) # + + +

Corrosion resistance + + + + + + + + +

+ + Excellent+ Very good[] Good# Good, but with reservations(1) Risk of powdering, based on Fe-Zn alliation rate(2) On electrogalvanized substrate(3) Compatibility to be verified, particularly in the case of Ni-free cataphoresis(4) Prone to cratering

Extragal Galvannealed Galfan Alusi Electrogalvanized TOC

Visible parts *Structural parts

suspension system components Exhaust system

Heat screens Under-hood parts

Fuel tanks

* Resin deposited on the non-visible side only.

As indicated, all automotive manufacturing sectors are called upon to make coating choices; no optimum solution can be identified across the board, since the options selected are determined by each manufacturer's specific constraints, know-how and judgment.

Currently options are under review as a result of three significant trends:

The ongoing extension of anti-corrosion guarantees is prompting automakers and equipment manufacturers to seek products offering the best possible corrosion performance; this has notably resulted in the widespread use of sheet coated on both sides.

1.

Environmental protection standards are being stepped up; this has a number of implications, including discontinuation of the use of heavy metals (especially Chromium VI) in coatings (particularly in zones liable to undergo sanding) and in surface treatments.

2.

Surface appearance has been improved by better control of "dedicated automotive" hot-dip coating processes, enabling these coatings to be used for the majority of visible parts and providing an opportunity for cost savings.

3.

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Surface appearance has been improved by better control of "dedicated automotive" hot-dip coating processes, enabling these coatings to be used for the majority of visible parts and providing an opportunity for cost savings.

3.

ArcelorMittal can supply an optimum coating for each system: alloyed and non-alloyed hot-dip and electrolytic metal coatingsin thicknesses ranging from approximately one micron to over 10 microns, with and without thin organic resin films and paint.

As part of the technical support service ArcelorMittal offers its customers, experts are available to help you make the best possible choice.


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Equivalent Standards Tables

The indicative tables below summarize the European standards corresponding to the ArcelorMittal product range. ArcelorMittal grades generally offer tighter mechanical property guarantees than the standards.

Dual Phase steels

prEN 10338 :2009(uncoated)

prEN 10338 :2009 + EN 10152 :2009

(electrogalvanized)

EN 10346 :2009(Extragal/Galvannealed)

FF 280 DP

Dual Phase 450 HCT450X HCT450X +ZE HCT450X +Z/ZF Dual Phase 500 HCT500X HCT500X +ZE HCT500X +Z Dual Phase 600 HCT600X HCT600X +ZE HCT600X +Z/ZF Dual Phase 780 Y450 HCT780X HCT780X +ZE HCT780X +Z/ZF Dual Phase 780 LCE Y450 HCT780X HCT780X +ZE HCT780X +Z/ZF Dual Phase 780 Y500

Dual Phase 980 LCE Y600 HCT980X HCT980X +ZE HCT980X +Z/ZF Dual Phase 980 LCE Y660

Dual Phase 980 Y700

Dual Phase 980 LCE Y700

Dual Phase 1180

Dual Phase 600 HDT580X Dual Phase 780

Hot rolled Cold rolled

FF 280 DP (Full Finished): grade specially developed for skin parts.LCE: Low Carbon Equivalent grade used to optimize properties in service.

While the ArcelorMittal grades conform perfectly well to the indicated EN standards, ArcelorMittal grades generally offer tighter mechanical properties (see table below).

TRIP (TRansformation Induced Plasticity) steels


prEN 10338 :2009 + EN 10152 :2009

(electrogalvanized)


TRIP 690 HCT690T HCT690T +ZE HCT690T +Z TRIP 780 HCT780T HCT780T +ZE HCT780T +Z/+ZF



Complex Phase steels

20

Complex Phase steels


prEN 10338 :2009 + EN 10152 :2009

(electrogalvanized)


Complex Phase 600 HCT600C HCT600C +ZE Complex Phase 800 Y500 HCT780C HCT780C +ZE Complex Phase 800 Y600 HCT780C HCT780C +ZE HCT780C +Z Complex Phase 1000 HCT980C HCT980C +ZE Complex Phase 1000 SF

Complex Phase 1000 Y800

Complex Phase 750 HDT750C HDT750C +Z Complex Phase 800 HDT780C HDT780C +Z Complex Phase 1000 HDT950C +Z


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).

Hot rolled ferrite-bainite steels

prEN 10338 :2009(uncoated)EN 10346 :2009

(Extragal)

FB 450 HDT450F HDT450F +Z FB 540

FB 560 HDT560F +Z FB 590 HDT590F FB 590 HHE*


HHE: High Hole Expansion

While the ArcelorMittal grades conform perfectly well to the indicated EN standards, ArcelorMittal grades generally offer tighter mechanical properties(see table below).

High strength low alloy (HSLA) steels for cold forming

EN 10268 :2006(uncoated)

EN 10268 :2006 + EN 10152 :2009

(electrogalvanized)

EN 10346 :2009(Extragal/galfan/

Galvannealed)

HSLA 260 HC260LA HC260LA +ZE HX260LAD +Z/+ZA/+ZF HSLA 300 HC300LA HC300LA +ZE HX300LAD +Z/+ZA/+ZF HSLA 340 HC340LA HC340LA +ZE HC340LAD +Z/+ZA/+ZF HSLA 380 HC380LA HC380LA +ZE HX380LAD +Z/+ZA/+ZF HSLA 420 HC420LA HC420LA +ZE HX420LAD +Z/+ZA/+ZF



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EN 10149-2 :1995

HSLA 320 S315MC HSLA 360 S355MC HSLA 420 S420MC HSLA 460 S460MC HSLA 500 S500MC HSLA 550 S550MC


While the ArcelorMittal grades conform perfectly well to the indicated EN standards, ArcelorMittal grades generally offer tighter mechanical properties(see table below).

Bake hardening steels


EN 10268 :2006 + EN 10152 :2009

(electrogalvanized)


180 BH HC180B HC180B +ZE HX180BD +Z 195 BH

220 BH HC220B HC220B +ZE HX220BD +Z 260 BH HC260B HC260B +ZE HX260BD +Z 300 BH HC300B HC300B +ZE HX300BD +Z



High strength IF steels


EN 10268 :2006 + EN 10152 :2009

(electrogalvanized)


IF 180 HC180Y HC180Y +ZE HX180YD +Z/+ZF IF 220 HC220Y HC220Y +ZE HX220YD +Z/+ZF IF 260 HC260Y HC260Y +ZE HX260YD +Z/+ZF IF 300 HX300YD +Z/+ZF



Solid solution steels

EN 10268 :2006(uncoated)EN 10268 :2006 + EN 10152 :2009

(electrogalvanized)

H 220 HC220P HC220P +ZE H 260 HC260P HC260P +ZE H 300 HC300P HC300P +ZE



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High formability steels for drawing

EN 10130 :2006(uncoated)EN 10152 :2009

(electrogalvanized)

ArcelorMittal 01 DC01 DC01+ZE ArcelorMittal 02

ArcelorMittal 03 DC03 DC03+ZE ArcelorMittal 04 DC04 DC04+ZE ArcelorMittal 05 DC05 DC05+ZE ArcelorMittal 06 DC06 DC06+ZE ArcelorMittal 07 DC07



ArcelorMittal 51 DX51D +Z/+ZF ArcelorMittal 52 DX52D +Z/+ZF ArcelorMittal 53 DX53D +Z/+ZF ArcelorMittal 54 DX54D +Z/+ZF ArcelorMittal 56 DX56D +Z/+ZF ArcelorMittal 57 DX57D +Z/+ZF



ArcelorMittal 11 DD11 ArcelorMittal 12 DD12 ArcelorMittal 13 DD13 ArcelorMittal 14 DD14 ArcelorMittal 15

ArcelorMittal 16




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Worldwide product availability

When the ArcelorMittal Group was set up, one of its major initiatives in the automotive sector was to draw up a worldwide catalogue covering the product range in the various regions in which the Group operates. This document shows:the very broad ArcelorMittal product offering, ranging from IF steels for deep drawing to very high strength hot stamped Usibor steels;1. the worldwide availability of a large number of widely used products and in particular a broad offering available in both North America and Europe;2. ongoing development aimed at further extending the availability of the worldwide product offering.3.

Products shown as being available in different regions do not necessarily have identical metallurgy. Customers interested in these products should contact their technical support structure about local mechanical property and chemical guarantees.ArcelorMittal R&D has pooled its available resources in the various regions. This enables new products to be developed simultaneously and consistently, reduces development times and ensures optimization of metallurgical choices. ArcelorMittal applies this ambitious product policy in order to offer its automotive sector customers strong support for their worldwide development.


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Dual Phase steels Very high strength steels

Description

Dual Phase steels offer an outstanding combination of strength and drawability as a result of their microstructure, in which a hard martensitic or bainitic phase is dispersed in a soft ferritic matrix. These steels have high strain hardenability. This gives them good strain redistribution capacity and thus drawability as well as finished part mechanical properties, including yield strength, that are far superior to those of the initial blank. The yield strength of Dual Phase steels is further increased by the paint baking (also called Bake Hardening, BH) process.

High finished part mechanical strength lends these steels excellent fatigue strength and good energy absorption capacity, making them suitable for use in structural parts and reinforcements. The strain hardening capacity of these steels combined with a strong bake hardening effect gives them excellent potential for reducing the weight of structural parts and even " notably in the case of FullFinished 280 DP (FF 280 DP) " skin parts.

Applications

Given their high energy absorption capacity and fatigue strength, cold rolled Dual Phase Steels are particularly well suited for automotive structural and safety parts such as longitudinal beams, cross members and reinforcements.FF 280 DPcan be used to make visible parts with 20% higher dent resistance than conventional high strength steels, resulting in a potential weight saving of some 15%.

As a result of its mechanical strength, hot rolled Dual Phase 600 can be used to reduce the weight of structural parts by decreasing their thickness. Relevant automotive applications include:

wheel webslongitudinal railsshock towersfasteners.

Bumper in Dual Phase 1180 (thickness: 1.35 mm)

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B-pillar reinforcement in Dual Phase 980 LCE Y600Extragal

Wheel web in hot rolled Dual Phase 600 -Patented VersaStyle wheel from Hayes Lemmerz International

ArcelorMittal has an extensive database on the forming and service characteristics of the entire range of Dual Phase steels. To integrate these steels at the design stage, a team of experts is available to carry out specific studies based on modeling and testing.

Designation and standard


prEN 10338 :2009 + EN 10152 :2009

(electrogalvanized)


FF 280 DP

Dual Phase 450 HCT450X HCT450X +ZE HCT450X +Z/ZF Dual Phase 500 HCT500X HCT500X +ZE HCT500X +Z Dual Phase 600 HCT600X HCT600X +ZE HCT600X +Z/ZF Dual Phase 780 Y450 HCT780X HCT780X +ZE HCT780X +Z/ZF Dual Phase 780 LCE Y450 HCT780X HCT780X +ZE HCT780X +Z/ZF Dual Phase 780 Y500

Dual Phase 980 LCE Y600 HCT980X HCT980X +ZE HCT980X +Z/ZF Dual Phase 980 LCE Y660

Dual Phase 980 Y700

Dual Phase 980 LCE Y700

Dual Phase 1180

Dual Phase 600 HDT580X

26

Dual Phase 780


FF 280 DP (Full Finished): grade specially developed for skin parts.LCE: Low Carbon Equivalent grade used to optimize properties in service.


Technical characteristics

Mechanical propertiesGuaranteed for 20x80 mm ISO tensile specimens (uncoated sheet)ST-Transverse direction (perpendicular to the rolling direction) /SL -Rolling direction

YS (MPa) UTS (MPa)ef (%)

L0 = 80 mmth < 3 mm

Ef (%)L0 = 5,65 S

0 (mm)th 3 mm

n BH2 (MPa) Direction

FF 280 DP* 300 -380 490 25 0,15 30 STDual Phase 450 280 -340 450 -530 27 0,16 30 STDual Phase 500 300 -380 500 -600 25 0,15 30 SLDual Phase 600 330 -410 600 -700 21 0,14 30 SLDual Phase 780 Y450 450 -550 780 -900 15 0,10 30 SLDual Phase 780 LCE

Y450 450 -550 780 -900 15 0,10 30 SL

Dual Phase 780 Y500 500 -600 780 -900 13 0,10 30 SLDual Phase 780 LCE

Y500 500 -600 780 -900 13 0,10 30 SL

Dual Phase 980 LCE Y600 600 -750 980 -1100 10 30 ST

Dual Phase 980 LCE Y660 660 -830 980 -1100 10 30 ST

Dual Phase 980 Y700 700 -850 980 -1100 8 30 SLDual Phase 980 LCE

Y700 700 -850 980 -1100 8 30 SL

Dual Phase 1180 900 -1100 1180 5 30 SLDual Phase 600 330 -460 580 -670 22 24 30 SLDual Phase 780* 450 750 15 18 30 SL


* The guarantees for this grade are subject to change.FF 280 DP (Full Finished): grade specially developed for skin parts.LCE: Low Carbon Equivalent grade, used to optimize properties in service.

Chemical Composition (%)

27

Chemical Composition (%)

C Mn Si Max Max Max

FF 280 DP 0,14 1,6 0,40 Dual Phase 450 0,08 1,6 0,40 Dual Phase 500 0,14 1,6 0,40 Dual Phase 600 0,14 2,1 0,40 Dual Phase 780 Y450 0,17 2,2 0,60 Dual Phase 780 LCE Y450 0,10 2,0 0,40 Dual Phase 780 Y500 0,17 2,2 0,60 Dual Phase 780 LCE Y500 0,10 2,0 0,40 Dual Phase 980 LCE Y600 0,11 2,9 0,70 Dual Phase 980 LCE Y660 0,11 2,9 0,70 Dual Phase 980 Y700 0,18 2,4 0,60 Dual Phase 980 LCE Y700 0,11 2,9 0,70 Dual Phase 1180 0,18 2,4 0,60 Dual Phase 600 0,09 1,0 0,25 Dual Phase 780 0,09 1,0 0,30


FF 280 DP (Full Finished): grade specially developed for skin parts.LCE: Low Carbon Equivalent grade, used to optimize properties in service.

Dual Phase 600

Dual Phase 980 Y700

28

The service properties of Dual Phase steels are guaranteed by the controlled manufacturing process. The controlled (temperature, cooling speed) annealing cycle in particular ensures achievement of the Dual Phase microstructure and reproducibility of mechanical properties.

Available coatings and surface conditions

Uncoated Electrogalvanized Galvannealed Extragal

FF 280 DP X Dual Phase 450 X X X X Dual Phase 500 X X X X Dual Phase 600 X X X X Dual Phase 780 Y450 X X O X Dual Phase 780 LCE Y450 X X Dual Phase 780 Y500 O X Dual Phase 780 LCE Y500 X X Dual Phase 980 LCE Y600 X X X X Dual Phase 980 LCE Y660 X Dual Phase 980 Y700 X X Dual Phase 980 LCE Y700 X X X Dual Phase 1180 X X Dual Phase 600 X Dual Phase 780 X


X available /O under developmentFF 280 DP (Full Finished): grade specially developed for skin parts.Please inquire about the availability of products shown as being under development or left blank in the table.LCE: Low Carbon Equivalent grade, used to optimize properties in service.

Recommendations for use and secondary processing

FormingDual Phase steels offer an excellent combination of strength and drawability as a result of their good ductility and strain hardening capacityfrom the beginning of deformation, which ensure homogeneous strain redistribution and reduce local thinning. For example, in Dual Phase 500, the yield strength increases by about 120 MPa after 2% of plastic strain in uniaxial tension (a phenomenon known as work hardening or WH2). The yield strength can be further increased through bake hardening (BH2) after paint curing.FF 280 DPcan also be used to manufacture skin parts, as a result of its excellent biaxial and uniaxial stretch formability.Dual Phase steels can be drawn on conventional tools, provided the settings are properly adjusted. For example, drawing pressure should be increased by approximately 20% for a Dual Phase 600, compared to a micro-alloyed (HSLA) type steel of the same thickness. It should be noted that these steels, especially the highest grades, are sensitive to the so-called springback phenomenon. Component geometry must be carefully studied during design (small die radius, reinforcement perpendicular to bends to stiffen open parts, etc.) and drawing sequence definition (overbending, calibration tool, punch stroke, increased blank-holder force, etc.).ArcelorMittal has developed expertise in controlling springback by means of part and drawing tool design (OUTIFO method).

Forming limit curves for the cold-rolled Dual Phase family of steels (typical data)

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For more information about the forming of Dual Phase steels in special thicknesses and with special coatings, please consult us.

Welding

Although Dual Phase steels are more highly alloyed than HSLA steels, they can be readily welded using conventional resistance spot welding processes, provided the parameters used in industrial conditions are adjusted. The table below gives indicative examples of spot weld properties for homogeneous Dual Phase steel joints complying with the ISO 18278-2 standard.

Coating Thickness (mm)Nugget diameter

(mm)Pure tensile

(kN)Weld diameter

(mm)Tensile-shear

(kN)

Dual Phase 500 - 1.5 8 14.2 8.8 18.4 Dual Phase 600 Extragal 1.5 7.7 13.1 9.5 22.3 Dual Phase 780 Extragal 1.5 8.9 10.5 9.4 25.6 Dual Phase 780

LCE - 1.5 7.6 14.3 6.6 22.7

Dual Phase 980 LCE Extragal 1.5 8.4 13.2 10.1 30.4

Dual Phase 600 - 3 11.6 32.6 11.2 46.7


For coated (galvanized and alloy galvanized) products, electrode life tests show values characteristic of the type of coating considered, with no significant modification due to the Dual Phase substrate.In butt or lap MAG (Metal Active Gas) arc welding, maximum hardness in the fusion zone does not exceed 300 HV for a Dual Phase 600, whatever the parameters. The weld seams meet ISO 25817 Class B requirements. Recommended welding consumables are:

Filler: G3Si1 NF EN 440;Protective gas: Ar + 8% CO2.

Dual phase steels have excellent mechanical strength in laser lap welding. Based on long shop-floor experience in characterizing its products, ArcelorMittal can provide technical assistance in adjusting the welding parameters for steels in the Dual Phase range.

Fatigue strength

As a result of their high mechanical strength, Dual Phase steels have good fatigue properties. Examples of Whler curves for a variety of Dual Phase steels are given in the two graphs below. The curves plot maximum stress versus number of cycles to failure. They are calculated for two loading ratios: tension-compression R=-1 and tension-tension R=0.1.

Whler curves or S-N curves for a variety of Dual Phase steels

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The graph below shows the low-cycle fatigue or E-N curves for the same steels. The curves plot strain amplitude versus number of reversals to failure (one cycle corresponds to two reversals). Other high and low cycle fatigue data can be provided on request.

ArcelorMittal can make a Dual Phase steel fatigue database available to its customers.

Impact strength

As a result of their very high tensile strength, Dual Phase steels are particularly suitable for parts designed to absorb energy during an impact.Dual Phase steels have been characterized in dynamic axial compression tests using an top hat structure with a spot-welded closure plate at an impact velocity of 56 kph. These tests have demonstrated the good impact behavior of these steels.

Mass reduction potential compared to that of an HSLA 380 steel (reference)


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TRIP (TRansformation Induced Plasticity) steels Very high strength steels

Description

TRIP steels offer an outstanding combination of strength and ductility as a result of their microstructure. They are thus suitable for structural and reinforcement parts of complex shape. The microstructure of these steels is composed of islands of hard residual austenite and carbide-free bainite dispersed in a soft ferritic matrix. Austenite is transformed into martensite during plastic deformation (TRIP: TRansformation Induced Plasticity effect), making it possible to achieve greater elongations and lending these steels their excellent combination of strength and ductility.

These steels have high strain hardening capacity. They exhibit good strain redistribution and thus good drawability. As a result of strain hardening, the mechanical properties, and especially the yield strength, of the finished part are far superior to those of the initial blank.High strain hardening capacity and high mechanical strength lend these steels excellent energy absorption capacity. TRIP steels also exhibit a strong bake hardening (BH) effect following deformation, which further improves their crash performance.The TRIP range of steels comprises 2 cold rolled grades in both uncoated and coated formats (TRIP 690 and TRIP 780) and one hot rolled grade (TRIP 780), identified by their minimum tensile strength expressed in MPa.

Applications

As a result of their high energy absorption capacity and fatigue strength, TRIP steels are particularly well suited for automotive structural and safety parts such as cross members, longitudinal beams, B-pillar reinforcements, sills and bumper reinforcements.ArcelorMittal has extensive data on the forming and service characteristics of the TRIP family of steels. To integrate these steels at the design stage, a team of experts is available to carry out specific studies based on modeling and experimental tests.

B-pillar reinforcement in electrogalvanized TRIP 780 (thickness: 1.2 mm)

Bumper cross memberin electrogalvanized TRIP 780 (thickness: 1.6 mm)


32



prEN 10338 :2009 + EN 10152 :2009

(electrogalvanized)


TRIP 690 HCT690T HCT690T +ZE HCT690T +Z TRIP 780 HCT780T HCT780T +ZE HCT780T +Z/+ZF




Mechanical propertiesGuaranteed for 20x80 mm ISO tensile specimens (uncoated sheets) with the tensile axix parallel to the rolling direction


L0 = 80 mmth < 3 mm

n BH2 (MPa)

TRIP 690 410 -510 690 -800 25 0,19 40TRIP 780* 450 -550 780 -900 23 0,18 40


* The product is also available with a minimum yield stress of 500 MPa

Typical cold rolled electrogalvanized TRIP 780 microstructure (residual austenite fraction about 18%)

Typical hot dip galvanized TRIP 690 microstructure (residual austenite fraction about 10%)

Chemical composition (%) 33

Chemical composition (%)

C Mn Al +Si Max Max Max

TRIP 690 0,200 2,0 2,0 TRIP 780 0,250 2,0 2,0


Available coatings

Uncoated Electrogalvanized Galvannealed Extragal

TRIP 690 X X X TRIP 780 X X X O


X Available-O Under development


FormingTRIP steels offer high ductility for their tensile strength. For example, cold rolled TRIP 780 has uniform elongation comparable to that of an ArcelorMittal 04.

The figure below shows examples of forming limit curves for cold rolled TRIP 690 and TRIP 780 steels in 1.5 mm thickness. Their formability is superior to that of a lower strength Dual Phase 600 steel.

Forming limit curves for TRIP 690 and 780 (thickness: 1.5 mm)

Please consult us for more information about the forming of TRIP steels.

In order to fully exploit the potential of TRIP steels, the metal characteristics after forming rather than those of the initial blank should be used in the design stage.

Because of their very good drawability, this family of steels can be used to make safety and structural parts with both simple and complex geometries, provided springback is taken into account at the design stage.

Welding

Resistance spot welding

TRIP steels can be readily welded using conventional welding processes, provided the parameters are adjusted. Because of the high carbon equivalent, electrode forces must be increased and welding cycles adjusted to obtain high-quality weld spots. The risk of interface fracture, which can occur in TRIP-TRIP welds, can be reduced by optimizing the welding parameters.

34

TRIP steels can be readily welded using conventional welding processes, provided the parameters are adjusted. Because of the high carbon equivalent, electrode forces must be increased and welding cycles adjusted to obtain high-quality weld spots. The risk of interface fracture, which can occur in TRIP-TRIP welds, can be reduced by optimizing the welding parameters.

The table below gives examples (indicative only) of spot welding parameters for TRIP 690 Extragal and TRIP 780 electrogalvanized matching joints, determined according to the ISO 18278-2 standard:

Coating Thickness (mm)Max. intensity

(kA)Nugget diameter

(mm)Pure tensile

(kN)Tensile-shear

(kN)

TRIP 690 Extragal 1.0 8.3 6.5 6.7 13

TRIP 780 Electrogalvanized 1.0 7.7 6.7 5.5 13.7


MAG arc welding

MAG (Metal Active Gas) arc welding employs a filler wire in a protective gas shield. It can be used for thicknesses greater than 0.8 mm. MAG weldability of TRIP 780 has been assessed using CMOS technology according to the EN 288 and EN 25817 standards for 1.5 mm thick butt joints. Heat input is of the order of 2 kJ/cm.

As a result of its chemical composition, TRIP 780 typically has a relatively high carbon equivalent of about 0.50. However, no particular precautions are needed to prevent cold cracking. The small thicknesses employed (< 2 mm) minimize restraint stresses during welding.

The most appropriate combination for MAG welding of TRIP 780 in a thickness range of about 1.5 mm is the following:Filler: G3Si1 type in accordance with EN 440;Protective gas: Ar + 8% CO2.

(M21 according to EN 439).

The CMOS evaluation shows satisfactory overall weld behavior meeting the mechanical strength criteria set out in the standards, given that:bends are good up to 120 and crack on the reverse side at 180;all tensile test failures occur in the base metal, even with G3Si1 filler metal, as a result of the associated dilution.

Laser welding

Laser welding tests have revealed no particular difficulties.Laser lap welding is particularly suitable for TRIP/TRIP joining.Based on long shop-floor experience in characterizing its products, ArcelorMittal can provide technical assistance in adjusting the welding parameters for all steels in the TRIP range.

Fatigue strength

Due to their high mechanical strength, TRIP grades have significantly better fatigue properties than conventional steels.

Examples of Whler curves for a variety TRIP grades are shown in the two graphs below. The curves plot maximum stress versus number of cycles to failure. They are calculated for two loading ratios: tension-compression R=-1 and tension-tension R=0.1.

Whler curves or S-N curves for TRIP steels

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The graph below shows the low-cycle fatigue or E-N curves for the same steels. The curves plot strain amplitude versus number of reversals to failure (one cycle corresponds to two reversals). Other high and low cycle fatigue data can be provided on request.

Low-cycle fatigue or E-N curves for TRIP steels

ArcelorMittal can make a TRIP steel fatigue database available to its customers.

Impact strength

As a result of their very high tensile strength, TRIP steels are particularly suitable for parts designed to absorb energy in an impact.

TRIP steels have been characterized in dynamic axial compression tests using an omega structure with a spot-welded closure plate at an impact velocity of 56 kph. These tests have demonstrated the very good impact behavior of these steels.

Mass reduction potential compared to that of an HSLA 380 steel (reference)

These results are obtained for specimens produced by bending. Strain hardening during drawing enhances the energy absorption capacity of this grade. In order to fully exploit the potential of TRIP steels, the metal characteristics after forming (hardening) rather than those of the initial blank should be used in the design stage. Crushing tests have shown a 9% gain in energy absorption of drawn parts compared to parts obtained by bending.


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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)

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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)



prEN 10338 :2009 + EN 10152 :2009

(electrogalvanized)


Complex Phase 600 HCT600C HCT600C +ZE Complex Phase 800 Y500 HCT780C HCT780C +ZE Complex Phase 800 Y600 HCT780C HCT780C +ZE HCT780C +Z Complex Phase 1000 HCT980C HCT980C +ZE Complex Phase 1000 SF

Complex Phase 1000 Y800

Complex Phase 750 HDT750C HDT750C +Z Complex Phase 800 HDT780C HDT780C +Z Complex Phase 1000 HDT950C +Z


SF(Stretch Flanging): grade specially developed for improved stretch flangeability.

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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).


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


L0 = 80 mmth < 3 mm

Direction

Complex Phase 600* 360 -440 600 -700 19 SLComplex Phase 800 Y500 500 -650 780 -900 13 SLComplex Phase 800 Y600 600 -700 780 -900 10 SLComplex Phase 1000 700 -850 980 -1200 8 SLComplex Phase 1000 SF 780 -950 980 -1200 7 SLComplex Phase 1000

Y800 800 -950 980 -1130 6 SL

Complex Phase 750 620 -750 750 10 SLComplex Phase 800 680 -830 780 10 STComplex Phase 1000* 800 -950 950 10 SL


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

Microstructure of hot rolled Complex Phase 1000


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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


SF(Stretch Flanging): grade specially developed for improved stretch flangeability.

Available coatings and surface conditions

Uncoated Electrogalvanized Extragal

Complex Phase 600 X X Complex Phase 800 Y500 X X O Complex Phase 800 Y600 X X X Complex Phase 1000 X X O Complex Phase 1000 SF X X O Complex Phase 1000 Y800 X Complex Phase 750 X X Complex Phase 800 X X Complex Phase 1000 O X


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


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:

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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.

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View of hole expansion in grades CR-CP 1000 andCR-CP 1000 SFin1.5 mm thickness.TheCP 1000 SPachieves 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


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.

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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)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


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

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 Whler 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.

Whler 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. 43

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)


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Hot rolled ferrite-bainite steels Very high strength steels

Description

This range of hot-rolled high strength steels has been developed to meet weight reduction requirements. It comprises four strength levels: FB 450, 540, 560 and 590. This family of steels extends the HSLA range of micro-alloyed steels to include products combining high tensile strength (UTS) with excellent formability and hole expansion (stretch flangeability) based on their ferrite-bainite microstructure.

Applications

These steels are cold-drawn. The main applications are:

structural parts (longitudinal beams, cross beams, car-body and ground liason parts),wheels,mechanical parts (ground liason parts, gear boxes...).

ArcelorMittal hasan extensive database relating to the forming and service properties of the entire range of ferrite-bainite steels. To integrate these steels at the design stage, a team of experts is available to perform specific studies based on modeling or laboratory tests.

Front and rear underseat cross member in galvanised FB 560 (thickness: 1.8 mm)

Suspension arm in uncoatedFB 540 (thickness: 4 mm)

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Suspension arm in Extragal FB 560 (thickness: 4 mm)

Pillar reinforcement in galvanised FB 560 (thickness: 1.8 mm)

Wheel in FB 590

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Designation and standa

festo

Documents

martinsite steels

plasticity steels

supplier of automotive

high formability steels

dual phase steels

complex phase steels

solid solution steels

ferritebainite steels