EP2028282B1 - Dual-phase steel, flat product made of such dual-phase steel and method for manufacturing a flat product - Google Patents

Dual-phase steel, flat product made of such dual-phase steel and method for manufacturing a flat product Download PDF

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Publication number
EP2028282B1
EP2028282B1 EP07114398A EP07114398A EP2028282B1 EP 2028282 B1 EP2028282 B1 EP 2028282B1 EP 07114398 A EP07114398 A EP 07114398A EP 07114398 A EP07114398 A EP 07114398A EP 2028282 B1 EP2028282 B1 EP 2028282B1
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EP
European Patent Office
Prior art keywords
dual
phase steel
weight
content
steel according
Prior art date
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EP07114398A
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German (de)
French (fr)
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EP2028282A1 (en
Inventor
Ekaterina Bocharova
Thomas Heller
Dorothea Mattissen
Thomas Nickels
Günter STICH
Silke Strauss
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ThyssenKrupp Steel Europe AG
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ThyssenKrupp Steel Europe AG
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Priority to EP07114398A priority Critical patent/EP2028282B1/en
Application filed by ThyssenKrupp Steel Europe AG filed Critical ThyssenKrupp Steel Europe AG
Priority to PL07114398T priority patent/PL2028282T3/en
Priority to ES07114398T priority patent/ES2387040T3/en
Priority to US12/673,388 priority patent/US20100273024A1/en
Priority to CN2008801034262A priority patent/CN101802233B/en
Priority to PCT/EP2008/060381 priority patent/WO2009021897A1/en
Priority to JP2010520536A priority patent/JP5486496B2/en
Publication of EP2028282A1 publication Critical patent/EP2028282A1/en
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Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12785—Group IIB metal-base component
    • Y10T428/12792—Zn-base component
    • Y10T428/12799—Next to Fe-base component [e.g., galvanized]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12861—Group VIII or IB metal-base component
    • Y10T428/12951—Fe-base component
    • Y10T428/12972—Containing 0.01-1.7% carbon [i.e., steel]

Definitions

  • the invention relates to a dual-phase steel, the structure of which consists essentially of martensite and ferrite or bainite, shares of retained austenite may be present and the dual-phase steel has a tensile strength of at least 950 MPa.
  • the invention likewise relates to a flat product produced from such a dual-phase steel and to methods for producing such a flat product.
  • flat product typically includes steel strips and sheets of the type according to the invention.
  • the EP 1 431 107 A1 a steel that is not only good deep-draw, but also has high tensile strength, a flat product produced from it and a method for its production known.
  • the well-known steel contains besides iron and the unavoidable impurities (in% by weight) 0.08 - 0.25% C, 0.001 - 1.5% Si, 0.01 - 2.0% Mn, 0, 001 - 0.06% P, to to 0.05% S, 0.001-0.007% N and 0.008-0.2% Al.
  • the upper limit of the content of Mn of 1.5% has been set in view of the decrease in the r values associated with exceeding this limit, with Mn contents in the range of 0.04 for optimizing the r values of the known steel sheet - 0.8 wt .-%, in particular 0.04 - 0.12 wt .-%, have been considered advantageous.
  • the known steel to further increase its strength in addition to other optionally added alloying elements also contents of B from 0.0001 to 0.01 wt .-% B, of Ti, Nb and / or V in a total amount of 0.001 to 0.2 wt .-% and Sn, Cr, Cu, Ni, Co, W and / or Mo in a total amount of 0.001 - have 2.5 wt .-%.
  • B contents of B from 0.0001 to 0.01 wt .-% B, of Ti, Nb and / or V in a total amount of 0.001 to 0.2 wt .-% and Sn, Cr, Cu, Ni, Co, W and / or Mo in a total amount of 0.001 - have 2.5 wt .-%.
  • the total content of these elements is limited to the respective upper limit.
  • the steels described have strengths of more than 850 MPa, they do not have a dual-phase structure, but theirs Structure consists either only of martensite or only of ferrite or bainite. Also found in the EP 1 431 407 A1 this is not an example, for example, by which the effects of Cr, Mo, Ti or B could be reconstructed with simultaneously small amounts of Si or higher contents of Mn. Rather, those in the EP 1 431 407 A1 Examples given that according to this prior art, the strength has been adjusted substantially by a suitable vote of the Mn and Si contents to the respective steel alloy.
  • the Martenistanteil of the steel in question is about 5% to 20% of the predominantly martensitic-ferritic microstructure.
  • a flat product produced in this way has strengths of at least 500 N / mm 2 and at the same time good formability, without requiring particularly high contents of certain alloying elements.
  • Cr may be provided in this alloy to increase the strength, according to the embodiments of the EP 1 808 505 A1 the Cr contents are each well below 0.05 wt .-%.
  • Al should be added to this known alloy on the one hand for deoxidation, on the other hand, but also to improve the toughness.
  • the in the EP 1 808 505 A1 specified embodiments show that this possibility of increasing the toughness has been taken up by adding high Al contents.
  • These known steel alloys which regularly reach tensile strengths of more than 600 MPa contain for this purpose (in% by weight) 0.05-0.5% C, 0.05-1.5% Si, 1-2.5% Mn , ⁇ 0.75% Cr, titanium as specified 0.01% ⁇ (Ti-2.4N) ⁇ 0.2% and / or Nb with the proviso 0.01% ⁇ (Nb-6.5N) ⁇ 0.2%, 0.01 - 1.5% Al, ⁇ 0.1% P, ⁇ 0.01% S, ⁇ 0.01% N, balance iron and unavoidable impurities.
  • the general alloying standard in question should contain 0.1-1% C, 0.05-2% Si, 1-5% Mn, 0.1-1% Cr, 0.005-0 , 1% Ti, 0.0003 - 0.01% B, 0.1 - 1% Mo, ⁇ 1% Al, 0.005 - 0.01% P and up to 0.01% N.
  • the strength values of example steels produced from this alloy spread over a wide range.
  • the object of the invention was to develop a steel and a flat product produced therefrom which reliably has a strength of at least 950 MPa and good deformability.
  • the steel should have a surface finish which, using a simple manufacturing process, allows a flat product produced from this steel, in the uncoated or corrosion-protective coating state, to deform into a complex shaped component, such as a part of an automobile body.
  • a method should also be given that allows in a simple manner to produce in the above-mentioned manner manufactured flat products.
  • a the above-mentioned object solving flat product according to claim 19 according to the invention characterized in that it consists of a composite according to the invention and procured steel.
  • a steel according to the invention is characterized by high strengths of at least 950 MPa, in particular more than 980 MPa, with regularities of 1000 MPa and more being achieved on a regular basis. At the same time it has a yield strength of at least 580 MPa, in particular at least 600 MPa, and has an elongation A 80 of at least 10%.
  • steel according to the invention is particularly suitable for the production of complex shaped, highly loaded in practical use components, such as those required in the field of bodywork for automobiles.
  • the alloy of a steel according to the invention is composed so that it has a martensite content of at least 20%, preferably more than 30%, up to a maximum of 70%.
  • the remainder of the microstructure of a dual-phase steel according to the invention consists respectively of ferrite and / or bainite (bainitic ferrite + carbides).
  • the high strengths and good elongation properties have been achieved by the adjustment of the dual-phase structure according to the invention. This has been made possible by a narrow selection of the contents of the individual alloying elements present in a steel according to the invention besides iron and unavoidable impurities.
  • the invention provides a C content of 0.10-0.20 wt%.
  • the minimum content of carbon of 0.10 wt .-% has been chosen to achieve the formation of martensitic structure with sufficient hardness and to set the desired combination of properties of the steel according to the invention.
  • carbon hinders the formation of the desired ferritic / bainitic portion of the structure.
  • higher C contents have a negative effect on the weldability, which is of particular importance for the application of the material according to the invention, for example in the field of automotive engineering.
  • the advantageous effect of carbon in a steel according to the invention can be used particularly reliably if the C content of a steel according to the invention is 0.12-0.18% by weight, in particular 0.15-0.16% by weight ,
  • Si also serves to increase the strength by hardening the ferrite or bainite.
  • the effect of Si is particularly safe when the Si content of a steel according to the invention is at least 0.2 wt .-%, in particular at least 0.25 wt .-% .
  • the upper limit of the Si content has at the same time been set at 0.6% by weight. Also, adherence to this upper limit minimizes the risk of grain boundary oxidation. In this case, an unfavorable influence of Si on the properties of the steel according to the invention can be avoided with even greater certainty that the Si content of the steel according to the invention is limited to 0.4% by weight, in particular 0.35% by weight.
  • the Mn content of a steel according to the invention is in the range of 1.5-2.5% by weight, in particular 1.5-2.35% by weight, in order to utilize the strength-increasing effect of this element.
  • the presence of Mn supports the formation of martensite.
  • the contents of Mn provided according to the invention prevent the formation of perlite during cooling after annealing, in particular in the case where a cold strip is produced from steel according to the invention and this cold strip is finally annealed.
  • the upper limit of the contents of Mn is on 2.5 wt .-% set in inventive steel.
  • the possibly negative influences of Mn on a steel according to the invention can be excluded with increased certainty that the Mn content is limited to 2.20% by weight, in particular 2.00% by weight.
  • Cr also strengthens in a dual phase steel at levels of 0.2-0.8% by weight. This effect occurs in particular when the Cr content according to the invention is at least 0.3% by weight, in particular at least 0.5% by weight. At the same time, however, the Cr content of a steel according to the invention is limited to 0.8% by weight in order to reduce the risk of grain boundary oxidation and to ensure good elongation properties of the steel according to the invention. Also, adherence to this upper limit achieves a surface that can be well provided with a metallic coating. Negative effects of the contents of Cr are avoided, in particular, if the upper limit of the chromium content of a steel according to the invention is set to not more than 0.7% by weight, in particular 0.6% by weight.
  • the presence of titanium at levels of at least 0.02% by weight also contributes to increasing the strength of a steel according to the invention by forming fine precipitates of TiC or Ti (C, N) and contributing to grain refining.
  • Another positive effect of Ti is the setting of possibly present nitrogen, so that the formation of boron nitrides in the steel according to the invention is prevented. These would have a strong negative impact on the elongation properties and, consequently, on the formability of a flat product according to the invention.
  • Ti thus ensures, in the case of an addition of boron to increase the strength, that the boron can fully develop its effect.
  • too high Ti contents lead to unfavorably high recrystallization temperatures, which has a negative effect, in particular, when cold-rolled flat products are produced from steel according to the invention, which are finally annealed. Therefore, the upper limit of the Ti content has been limited to 0.08 wt%, especially 0.06 wt%.
  • the positive influence of Ti on the properties of a steel according to the invention can be used particularly reliably if its Ti content is 0.03-0.055% by weight, in particular 0.040-0.050% by weight.
  • the strength of the steel according to the invention is also increased by the amounts of B, which are optionally provided according to the invention, of up to 0.002% by weight and, as in the case of the addition of Mn, Cr and Mo in the case of the production of cold strip of steel according to the invention, the critical cooling rate lowered after annealing. Therefore, according to a particularly practical embodiment of the invention, the B content is at least 0.0005 wt .-%. At the same time, however, excessively high contents of B can reduce the deformability of the steel according to the invention and adversely affect the expression of the dual-phase structure desired according to the invention. Optimized effects of boron therefore result in a steel according to the invention Contents of 0.0007 - 0.0016 wt .-%, in particular 0.0008 - 0.0013 wt .-%.
  • the inventively optional levels of molybdenum contribute to increasing the strength of a steel according to the invention.
  • the presence of Mo does not adversely affect the coatability of the flat product with a metallic coating and its ductility.
  • Practical experiments have shown that the positive effects of Mo up to contents of 0.25% by weight, in particular 0.22% by weight, can be used particularly effectively, even from a cost point of view.
  • contents of 0.05% by weight Mo have a positive effect on the properties of the steel according to the invention.
  • the desired effect of molybdenum in a steel according to the invention occurs in particular if its Mo content is 0.065-0.18% by weight, in particular 0.08-0.13% by weight, is.
  • Mo contents of less than 1.7% by weight and / or Cr contents of less than 0.4% by weight are present in the steel according to the invention, it is advantageous to secure the required strength of the invention Steel 0.05 - 0.22 wt .-% Mo added.
  • Aluminum is used in the melting of a steel according to the invention for deoxidizing and for setting nitrogen which may be present in the steel.
  • Al may be added in amounts of less than 0.1% by weight to the steel of the present invention, with the desired effect of Al being particularly safe occurs when its contents in the range of 0.01 to 0.06 wt .-%, in particular 0.020 to 0.050 wt .-%, are.
  • Nitrogen is allowed in inventive steel only in amounts of up to 0.012 wt .-%, in order to avoid the formation of boron nitrides especially in the simultaneous presence of B.
  • the N content is preferably limited to 0.007% by weight.
  • the P content according to the invention is preferably limited to ⁇ 0.1 wt .-%, in particular ⁇ 0.02 wt .-%, with particularly good results at P contents of ⁇ 0.010 wt .-% can be achieved.
  • existing flat products can be supplied as immediately after hot rolling hot strip, ie without subsequently performed cold rolling process, further processing.
  • obtained hot strip in uncoated state form highly resilient components. If these components are to be particularly protected against corrosion, then the hot strips can be provided before or after their transformation to the respective component with a metallic protective coating.
  • the hot strips produced from steel according to the invention can first be subjected to cold rolling and subsequent annealing, in which case they can be further processed as cold strip, if appropriate after application of a metallic coating which protects against corrosion.
  • the flat product according to the invention is provided with a metallic protective coating, this can be done, for example, by hot-dip galvanizing, galvannealing or electrolytic coating. If necessary, a pre-oxidation can be carried out before the coating in order to ensure a secure connection of the metallic coating to the respective substrate to be coated.
  • a dual phase steel composed according to the invention is first melted, the melt is cast into a precursor, such as slab or thin slab, the primary product reheated or held at a hot rolling start temperature of 1100-1300 ° C, the precursor at a hot rolling end temperature of 800-950 ° C to the Hot rolled hot strip and the hot strip obtained at a reel temperature of up to 570 ° C reeled.
  • a precursor such as slab or thin slab
  • the primary product reheated or held at a hot rolling start temperature of 1100-1300 ° C
  • the precursor at a hot rolling end temperature of 800-950 ° C to the Hot rolled hot strip and the hot strip obtained at a reel temperature of up to 570 ° C reeled.
  • the dual-phase structure of the as such subsequently no longer rolled hot strip can be adjusted to obtain the desired combination of properties.
  • the hot strip obtained in the manner according to the invention should remain uncoated or be electrolytically coated with a metallic coating as a hot strip, no annealing of the flat product is required.
  • the hot-rolled strip is to be coated with a metallic coating by hot-dip galvanizing, then it is first annealed at a maximum annealing temperature of 600 ° C. and then cooled to the temperature of the coating bath, which may be, for example, a zinc bath. After passing through the zinc bath, the coated hot strip can be conventionally cooled to room temperature.
  • a dual phase steel composed according to the invention is melted, the corresponding molten steel is cast into a precursor, such as a slab or thin slab, and the primary product is reheated or held at a hot rolling start temperature of 1100 to 1300 ° C. , the precursor hot rolled at a hot rolling end temperature of 800 - 950 ° C to a hot strip, the hot strip at a reel temperature of 500 - 650 ° C, the cold rolled after hot rolling, the cold strip obtained at annealed at a 700-900 ° C annealing temperature and the cold strip cooled after annealing controlled.
  • a precursor such as a slab or thin slab
  • the primary product is reheated or held at a hot rolling start temperature of 1100 to 1300 ° C.
  • the precursor hot rolled at a hot rolling end temperature of 800 - 950 ° C to a hot strip the hot strip at a reel temperature of 500 - 650 ° C
  • the cold rolled after hot rolling the cold
  • Coiling temperatures in the range of up to 580 ° C have proven to be particularly advantageous in connection with the production of cold strip, because when exceeding the coiler temperature of 580 ° C, the risk of grain boundary oxidation increases. With low reel temperatures, the strength and yield strength of the hot strip increases, so that the hot strip can be cold rolled more and more difficult. Accordingly, the cold strip to be cold rolled to cold strip is preferably at least 530 ° C, in particular at least 550 ° C, reeled.
  • the cold strip produced according to the invention remains uncoated or is to be electrolytically coated, an annealing treatment in a continuous annealing anneal takes place as a separate working step.
  • the maximum annealing temperatures achieved are in the range of 700-900 ° C at heating rates of 1-50 K / s.
  • the annealed cold strip for the targeted setting of the desired property combination according to the invention is preferably cooled in such a way that in the temperature range of 550-650 ° C cooling rates of at least 10 K / s are achieved in order to suppress the formation of perlite.
  • the strip can be held for a period of 10 to 300 s or cooled directly to room temperature at a cooling rate of 0.5 to 30 K / s.
  • the cold strip is to be coated by hot dip galvanizing, then the steps of annealing and coating can be combined.
  • the steps of annealing and coating can be combined.
  • the strip is then held at this temperature for 10-200 seconds.
  • the strip is then cooled to the temperature of the respective coating bath, which is typically below 500 ° C., which is typically a zinc bath, the cooling rate also being more than 10 K in the temperature range 550-650 ° C. in this case / s should be.
  • the cold strip can be held at the respective temperature for 10 - 300 s.
  • the annealed cold strip passes through the respective coating bath, which is preferably a zinc bath. This is followed by either cooling to room temperature to obtain a conventionally hot-dip galvanized cold-rolled strip or rapid heating followed by cooling to room temperature to produce a galvannealed cold-rolled strip.
  • Such cold-rolled cold rolled strip according to the invention typically has thicknesses of 0.8-2.5 mm.
  • the cold-rolled strip may be in the coated or uncoated state of a temper rolling mill be subjected to be applied in which lying in the range of up to 2% lying Dressiergrade.
  • the hot rolled strips thus obtained were rewound at a coiler temperature of 550 ° C., adjusted to an accuracy of +/- 30 ° C., before being cold rolled to a thickness of 50%, 65% and 70%, respectively from 0.8 mm to 2 mm cold rolled.
  • the cold strips obtained have been subjected to annealing and controlled cooling in the manner already described above in general form for a cold-rolled strip to be delivered uncoated.
  • Table 2 shows the microstructural state, the mechanical properties as well as the respectively set cold rolling degrees and strip thicknesses for the cold strips produced in the first test series from melts 1 to 16.
  • Table 1 melt C Si Mn al Not a word Ti Cr B P S N 1* 0,149 0.30 1.97 0,007 - - 0.45 0.0004 0,003 0,004 0.0013 2 * 0,150 0.30 1.97 ⁇ 0.005 - 0.023 0.45 0.0021 0.005 0,004 0,015 3 * 0,152 0.30 1.99 0.005 - - 0.46 0.0004 0,004 0,004 0.0014 4 * 0,157 0.30 1.97 0.005 - - 0.81 0.0005 0,004 0,004 0.0017 5 * 0.153 0.30 1.50 0.005 - - 0.81 0.0004 0,004 0,004 0.0015 6 * 0,150 0.02 1.98 ⁇ 0.005 - 0.023 0.80 0.0022 0,004 0.005 0.0015 7 0,152 0.60 1.97 ⁇ 0.005 - 0,021 0.45 0.0022 0,004 0,004 0.0024 8th 0.154 0.19 2.07 0,004 - 0,022 0.60 0.0011 0,004 0,007

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  • Mechanical Engineering (AREA)
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Description

Die Erfindung betrifft einen Dualphasenstahl, dessen Gefüge im Wesentlichen aus Martensit und Ferrit bzw. Bainit besteht, wobei Anteile an Restaustenit vorhanden sein können und der Dualphasenstahl eine Zugfestigkeit von mindestens 950 MPa aufweist. Ebenso betrifft die Erfindung ein aus einem solchen Dualphasenstahl hergestelltes Flachprodukt sowie Verfahren zur Herstellung eines solchen Flachprodukts.The invention relates to a dual-phase steel, the structure of which consists essentially of martensite and ferrite or bainite, shares of retained austenite may be present and the dual-phase steel has a tensile strength of at least 950 MPa. The invention likewise relates to a flat product produced from such a dual-phase steel and to methods for producing such a flat product.

Unter den Oberbegriff "Flachprodukt" fallen hier typischerweise Stahlbänder und -bleche der erfindungsgemäßen Art.The generic term "flat product" typically includes steel strips and sheets of the type according to the invention.

Gerade im Bereich des Fahrzeugkarosseriebaus besteht die Forderung nach Stählen, die einerseits bei geringem Gewicht eine hohe Festigkeit, andererseits jedoch auch eine gute Verformbarkeit besitzen. Es ist eine große Zahl von Versuchen bekannt, Stähle zu erzeugen, die diese an sich widersprüchlichen Eigenschaften in sich vereinen.Especially in the field of vehicle bodyworking, there is a demand for steels which on the one hand have high strength on the one hand with low weight, but on the other hand also have good deformability. There are a large number of attempts to produce steels that combine these inherently contradictory properties.

So sind beispielsweise aus der EP 1 431 107 A1 ein Stahl, der nicht nur gut tiefziehbar sein soll, sondern auch hohe Zugfestigkeiten besitzt, ein daraus hergestelltes Flachprodukt und ein Verfahren zu dessen Herstellung bekannt. Der bekannte Stahl enthält neben Eisen und den unvermeidbaren Verunreinigungen (in Gew.-%) 0,08 - 0,25 % C, 0, 001 - 1,5 % Si, 0,01 - 2,0 % Mn, 0, 001 - 0,06 % P, bis zu 0,05 % S, 0,001 - 0,007 % N und 0,008 - 0,2 % Al. Gleichzeitig soll er einen mittleren r-Wert von mindestens 1,2, einen r-Wert in Walzrichtung von mindestens 1,3, einen r-Wert in einer Richtung von 45° bezogen auf die Walzrichtung von mindestens 0,9 und einen r-Wert quer zur Walzrichtung von mindestens 1,2 aufweisen. In dem bekannten Stahl wird Silizium eine festigkeitssteigernde Wirkung zugeschrieben, wobei die Obergrenze von 1,5 Gew.-% im Hinblick auf eine gute Beschichtbarkeit des Stahls gewählt worden ist. Ebenso wird der positive Einfluss von Mn auf die Festigkeit hervorgehoben. Dabei ist die Obergrenze des Gehalts an Mn von 1,5 % im Hinblick auf die mit dem Überschreiten dieser Grenze einhergehende Abnahme der r-Werte gesetzt worden, wobei zur Optimierung der r-Werte des bekannten Stahlblechs Mn-Gehalte im Bereich von 0,04 - 0,8 Gew.-%, insbesondere 0,04 - 0,12 Gew.-%, als vorteilhaft angesehen worden sind.For example, from the EP 1 431 107 A1 a steel that is not only good deep-draw, but also has high tensile strength, a flat product produced from it and a method for its production known. The well-known steel contains besides iron and the unavoidable impurities (in% by weight) 0.08 - 0.25% C, 0.001 - 1.5% Si, 0.01 - 2.0% Mn, 0, 001 - 0.06% P, to to 0.05% S, 0.001-0.007% N and 0.008-0.2% Al. At the same time, it should have a mean r-value of at least 1.2, an r-value in the rolling direction of at least 1.3, an r-value in a direction of 45 ° with respect to the rolling direction of at least 0.9 and an r-value transverse to the rolling direction of at least 1.2. In the known steel, silicon is attributed a strength-increasing effect, with the upper limit of 1.5% by weight having been selected in view of good coatability of the steel. Likewise, the positive influence of Mn on strength is emphasized. In this case, the upper limit of the content of Mn of 1.5% has been set in view of the decrease in the r values associated with exceeding this limit, with Mn contents in the range of 0.04 for optimizing the r values of the known steel sheet - 0.8 wt .-%, in particular 0.04 - 0.12 wt .-%, have been considered advantageous.

Optional kann der bekannte Stahl zur weiteren Steigerung seiner Festigkeit neben anderen wahlweise zugegebenen Legierungselementen auch Gehalte an B von 0.0001 - 0.01 Gew.-% B, an Ti, Nb und/oder V in einer Gesamtmenge von 0.001 - 0.2 Gew.-% sowie an Sn, Cr, Cu, Ni, Co, W und / oder Mo in einer Gesamtmenge von 0.001 - 2.5 Gew.-% aufweisen. Aus Kostengründen ist dabei der Gesamtgehalt dieser Elemente auf die jeweils angegebene Obergrenze beschränkt.Optionally, the known steel to further increase its strength in addition to other optionally added alloying elements also contents of B from 0.0001 to 0.01 wt .-% B, of Ti, Nb and / or V in a total amount of 0.001 to 0.2 wt .-% and Sn, Cr, Cu, Ni, Co, W and / or Mo in a total amount of 0.001 - have 2.5 wt .-%. For cost reasons, the total content of these elements is limited to the respective upper limit.

Sofern die in der EP 1 431 407 A1 beschriebenen Stähle Festigkeiten von mehr als 850 MPa besitzen, weisen sie allerdings kein Dualphasengefüge mehr auf, sondern ihr Gefüge besteht entweder nur aus Martensit oder nur aus Ferrit bzw. Bainit. Auch findet sich in der EP 1 431 407 A1 kein Beispiel, anhand dessen beispielsweise die Wirkungen von Cr, Mo, Ti oder B bei gleichzeitig geringen Mengen an Si oder höheren Gehalten an Mn nachvollzogen werden könnten. Vielmehr belegen die in der EP 1 431 407 A1 angegebenen Beispiele, dass gemäß diesem Stand der Technik die Festigkeit im Wesentlichen durch eine geeignete Abstimmung der Mn- und Si-Gehalte zur jeweiligen Stahllegierung eingestellt worden ist.Unless in the EP 1 431 407 A1 Although the steels described have strengths of more than 850 MPa, they do not have a dual-phase structure, but theirs Structure consists either only of martensite or only of ferrite or bainite. Also found in the EP 1 431 407 A1 this is not an example, for example, by which the effects of Cr, Mo, Ti or B could be reconstructed with simultaneously small amounts of Si or higher contents of Mn. Rather, those in the EP 1 431 407 A1 Examples given that according to this prior art, the strength has been adjusted substantially by a suitable vote of the Mn and Si contents to the respective steel alloy.

Eine weitere Möglichkeit der Erzeugung von aus höherfesten Dualphasenstählen bestehenden Flachprodukten, die auch nach Durchlauf eines Glühprozesses unter Einschluss einer Überalterungsbehandlung noch gute mechanisch-technologische Eigenschaften besitzen, ist aus der EP 1 200 635 A1 bekannt. Bei dem aus dieser Druckschrift bekannt Verfahren wird ein Stahlband oder -blech erzeugt, welches ein überwiegend ferritischmartensitisches Gefüge aufweist, an welchem der Martensitanteil zwischen 4 bis 20 % beträgt, wobei das Stahlband oder -blech neben Fe und erschmelzungsbedingten Verunreinigungen (in Gew.-%) 0,05 - 0,2 % C, bis zu 1,0 % Si, bis zu 2,0 % Mn, bis zu 0,1 % P, bis zu 0,015 % S, 0,02 - 0,4 % Al, bis zu 0,005 % N, 0,25 - 1,0 % Cr, 0,002 - 0,01 % B enthält. Vorzugsweise beträgt dabei der Martenistanteil des betreffenden Stahls rund 5 % bis 20 % des überwiegend martensitisch-ferritischen Gefüges. Ein solcherart erzeugtes Flachprodukt weist Festigkeiten von mindestens 500 N/mm2 bei gleichzeitig gutem Umformvermögen auf, ohne dass dazu besonders hohe Gehalte an bestimmten Legierungselementen erforderlich sind.Another possibility of producing high-strength dual-phase steels flat products, which still have good mechanical and technological properties even after passing through an annealing process including an overaging treatment, is from the EP 1 200 635 A1 known. In the process known from this document, a steel strip or sheet is produced which has a predominantly ferritic-martensitic microstructure in which the martensite fraction is between 4 and 20%, the steel strip or sheet containing Fe and melt-caused impurities (in% by weight). ) 0.05-0.2% C, up to 1.0% Si, up to 2.0% Mn, up to 0.1% P, up to 0.015% S, 0.02-0.4% Al containing up to 0.005% N, 0.25-1.0% Cr, 0.002-0.01% B. Preferably, the Martenistanteil of the steel in question is about 5% to 20% of the predominantly martensitic-ferritic microstructure. A flat product produced in this way has strengths of at least 500 N / mm 2 and at the same time good formability, without requiring particularly high contents of certain alloying elements.

Zur Steigerung der Festigkeit ist bei dem in der EP 1 200 635 A1 beschriebenen Stahl auf den umwandlungsbeeinflussenden Effekt des Elementes Bor zurückgegriffen worden. Dessen festigkeitssteigernde Wirkung wird bei dem bekannten Stahl dadurch sichergestellt, dass dem Stahlwerkstoff mindestens ein alternativer Nitridbildner, vorzugsweise Al und ergänzend Ti, beigegeben wird. Die Wirkung der Zugabe an Titan und Aluminium besteht darin, dass sie den im Stahl enthaltenen Stickstoff binden, so dass Bor zur Bildung von härtesteigernden Karbiden zur Verfügung steht. Unterstützt durch den notwendig vorhandenen Cr-Gehalt wird auf diese Weise ein höheres Festigkeitsniveau erreicht als bei vergleichbaren Stählen. Jedoch liegt das Maximum der Festigkeit der in der EP 1 200 635 beispielhaft angegebenen Stähle jeweils unterhalb von 900 MPa.To increase the strength is in the in the EP 1 200 635 A1 described steel has been resorted to the conversion-influencing effect of the element boron. Its strength-increasing effect is ensured in the known steel in that at least one alternative nitride former, preferably Al and additionally Ti, is added to the steel material. The effect of the addition of titanium and aluminum is that they bind the nitrogen contained in the steel, so that boron is available for the formation of hardness-increasing carbides. Supported by the necessary Cr content, a higher strength level is achieved in this way than with comparable steels. However, the maximum of the strength lies in the EP 1 200 635 Steels exemplified below 900 MPa.

Schließlich ist aus der EP 1 559 797 A1 ein höherfester Dualphasenstahl mit einem mehr als 60 % Ferrit und 5 - 30 % Martensit aufweisenden Gefüge bekannt, der neben Eisen und unvermeidbaren Verunreinigungen (in Gew.-%) 0, 05 - 0,15 % C, bis zu 0,5 % Si, 1 - 2 % Mn, 0,01 - 0,1 % Al, bis zu 0,009 % P, bis zu 0,01 % S und bis zu 0,005 % N enthält. Um seine Festigkeit weiter zu erhöhen, können diesem bekannten Stahl 0,01 - 0,3 % Mo, 0,001 - 0,05 % Nb, 0,001 - 0,1 % Ti, 0,0003 - 0,002 % B, und 0,05 - 0,49 % Cr zugegeben werden. Der in dieser Weise legierte und beschaffene bekannte Stahl erreicht bei einer guten Verformbarkeit und Oberflächenbeschaffenheit Zugfestigkeiten von bis zu 700 MPa. Ziel der in der EP 1 559 797 A1 beschriebenen Entwicklung war dabei eine Verbesserung der mechanischen Eigenschaften eines solchen Stahls unter Vermeidung einer Zulegierung von größeren Mengen an hinsichtlich der Oberflächenbeschaffenheit, Verschweißbarkeit und Verformbarkeit kritischen Legierungselementen, wie Si, P und Al.Finally, out of the EP 1 559 797 A1 a higher-strength dual-phase steel with a structure containing more than 60% ferrite and 5-30% martensite, which in addition to iron and unavoidable impurities (in wt .-%) 0, 05 - 0.15% C, up to 0.5% Si , 1 - 2% Mn, 0.01 - 0.1% Al, up to 0.009% P, up to 0.01% S and up to 0.005% N. To further increase its strength, this known steel may contain 0.01-0.3% Mo, 0.001-0.05% Nb, 0.001-0.1% Ti, 0.0003-0.002% B, and 0.05. 0.49% Cr can be added. The well-known steel alloyed and obtained in this way achieves tensile strengths of up to 700 MPa with good ductility and surface finish. Goal of in the EP 1 559 797 A1 The development described here was an improvement in the mechanical properties of such a steel while avoiding the addition of larger Amounts of surface alloy, weldability and ductility critical alloying elements such as Si, P and Al.

Neben dem voranstehend erläuterten Stand der Technik ist aus der EP 1 808 505 A1 ein Stahl mit (in Gew.-%) 0,03 - 0,25 C, 0,4 - 2,0 Si, 0,8 - 3,1 Mn, 0,005 - 2 Cr, 0,002 - 1 Ti, 0,0002 - 0,1 B, 0,005 - 1 Mo, ≤ 2,0 Al, ≤ 0,02 P, ≤ 0,02 S, ≤ 0,01 N, Rest Eisen und unvermeidbare Verunreinigungen bekannt, dessen Gefüge neben Bainit 10 - 60 % Martensit, 1 - 10 % Restaustenit sowie 10 - 80 % Ferrit enthalten soll. Cr kann in dieser Legierung zur Steigerung der Festigkeit vorgesehen sein, wobei nach den Ausführungsbeispielen der EP 1 808 505 A1 die Cr-Gehalte jeweils deutlich unterhalb von 0,05 Gew.-% liegen. Al soll dieser bekannten Legierung einerseits zur Desoxidation, andererseits aber auch zur Verbesserung der Zähigkeit zugegeben werden. Die in der EP 1 808 505 A1 angegebenen Ausführungsbeispiele zeigen, dass diese Möglichkeit der Steigerung der Zähigkeit durch Zugabe hoher Al-Gehalte aufgegriffen worden ist.In addition to the above-described prior art is from the EP 1 808 505 A1 a steel having (in wt%) 0.03-0.25 C, 0.4-2.0 Si, 0.8-3.1 Mn, 0.005-2 Cr, 0.002-1 Ti, 0.0002 - 0.1 B, 0.005 - 1 Mo, ≤ 2.0 Al, ≤ 0.02 P, ≤ 0.02 S, ≤ 0.01 N, the remainder iron and unavoidable impurities known, whose structure in addition to bainite 10 - 60% Martensite, 1 - 10% retained austenite and 10 - 80% ferrite. Cr may be provided in this alloy to increase the strength, according to the embodiments of the EP 1 808 505 A1 the Cr contents are each well below 0.05 wt .-%. Al should be added to this known alloy on the one hand for deoxidation, on the other hand, but also to improve the toughness. The in the EP 1 808 505 A1 specified embodiments show that this possibility of increasing the toughness has been taken up by adding high Al contents.

Ebenso ist aus der EP 1 319 726 A1 ein Legierungskonzept bekannt, das auf dem Gedanken gründet, einem Stahl eine Menge an Mikrolegierungselementen zuzugeben, die ausreicht, um einerseits den im Stahl vorhandenen Stickstoff zu binden und andererseits festigkeitssteigernde Ausscheidungen zu bilden. Diese bekannte, Zugfestigkeiten von mehr als 600 MPa regelmäßig erreichende Stahllegierung enthält zu diesem Zweck (in Gew.-%) 0,05 - 0,5 % C, 0,05 - 1,5 % Si, 1 - 2,5 % Mn, ≤ 0,75 % Cr, Titan mit der Maßgabe 0,01 % ≤ (Ti-2,4N) ≤ 0,2 % und/oder Nb mit der Maßgabe 0,01 % ≤ (Nb-6,5N) ≤ 0,2 %, 0,01 - 1,5 % Al, ≤ 0,1% P, ≤ 0,01% S, ≤ 0,01% N, Rest Eisen und unvermeidbare Verunreinigungen.Likewise is from the EP 1 319 726 A1 An alloy concept is known which is based on the idea of adding to a steel a quantity of micro-alloying elements which is sufficient, on the one hand, to bind the nitrogen present in the steel and, on the other hand, to form strength-enhancing precipitates. These known steel alloys which regularly reach tensile strengths of more than 600 MPa contain for this purpose (in% by weight) 0.05-0.5% C, 0.05-1.5% Si, 1-2.5% Mn , ≤ 0.75% Cr, titanium as specified 0.01% ≤ (Ti-2.4N) ≤ 0.2% and / or Nb with the proviso 0.01% ≤ (Nb-6.5N) ≤ 0.2%, 0.01 - 1.5% Al, ≤ 0.1% P, ≤ 0.01% S, ≤ 0.01% N, balance iron and unavoidable impurities.

Aus der EP 1 548 142 A1 geht des Weiteren eine allgemeine Legierungsvorschrift hervor, innerhalb der die durch diverse von den Gehalten ihrer Legierungselemente einzuhaltende Bedingungen näher charakterisierten Stahlzusammensetzungen liegen sollen. Die betreffende allgemeine Legierungsvorschrift soll neben Eisen und unvermeidbaren Verunreinigungen (in Gew.-%) 0,1 - 1% C, 0,05 - 2 % Si, 1 - 5 % Mn, 0,1 - 1 % Cr, 0,005 - 0,1 % Ti, 0,0003 - 0,01 % B, 0,1 - 1 % Mo, ≤ 1 % Al, 0,005 - 0,01 % P und bis zu 0,01 % N enthalten. Die Festigkeitswerte von aus dieser Legierung erzeugten Beispielsstählen streuen über einen weiten Bereich.From the EP 1 548 142 A1 In addition, a general alloying regulation emerges, within which the steel compositions should be more closely characterized by various conditions to be met by the contents of their alloying elements. In addition to iron and unavoidable impurities (in% by weight), the general alloying standard in question should contain 0.1-1% C, 0.05-2% Si, 1-5% Mn, 0.1-1% Cr, 0.005-0 , 1% Ti, 0.0003 - 0.01% B, 0.1 - 1% Mo, ≤ 1% Al, 0.005 - 0.01% P and up to 0.01% N. The strength values of example steels produced from this alloy spread over a wide range.

Aus der EP 0 966 547 B1 ist schließlich auch noch ein Alberuhigter Mehrphasenstahl bekannt, der (in Gew.-%) 0,10 - 0,20 % C, 0,30 - 0,60 % Si, 1,50 - 2,00 % Mn, 0,30 - 0,80 % Cr, ≤ 0,2 % Ti, ≤ 0,40 % Mo, ≤ 0,08 % P, ≤ 0,8 % Nb, Zr ≤ 0,2, Rest Eisen und unvermeidbare Verunreinigungen enthält und Zugfestigkeiten von mindestens 900 MPa aufweisen soll. Diese Legierung gründet auf dem Gedanken, in dem Stahl sehr feine Mikrostrukturen zu bilden, die aus weichen und harten Phasen nebeneinander, kombiniert mit einer Verteilung feinster Ausscheidungen bestehen. Die Wirkung von Cr wird dabei darin gesehen, dass dieses Element die Entstehung von Bainit fördert. Gleichzeitig werden hohe Ti-Gehalte empfohlen, um eine maximale Anzahl feinstverteilter Ti-Ausscheidungen zu erzeugen.From the EP 0 966 547 B1 Finally, there is also known an Al-killed multiphase steel which contains (in% by weight) 0.10-0.20% C, 0.30-0.60% Si, 1.50-2.00% Mn, 0.30 0.80% Cr, ≤ 0.2% Ti, ≤ 0.40% Mo, ≤ 0.08% P, ≤ 0.8% Nb, Zr ≤ 0.2, remainder contains iron and unavoidable impurities and tensile strengths of should have at least 900 MPa. This alloy is based on the idea of forming very fine microstructures in the steel, which consist of soft and hard phases next to each other, combined with a distribution of finest precipitates. The effect of Cr is seen in the fact that this element promotes the formation of bainite. At the same time high Ti contents recommended to produce a maximum number of finely divided Ti precipitates.

Vor dem Hintergrund des voranstehend beschriebenen Standes der Technik lag der Erfindung die Aufgabe zu Grunde, einen Stahl und ein daraus hergestelltes Flachprodukt zu entwickeln, das zuverlässig eine Festigkeit von mindestens 950 MPa und eine gute Verformbarkeit aufweist. Darüber hinaus sollte der Stahl eine Oberflächenbeschaffenheit besitzen, die es unter Anwendung eines einfachen Herstellverfahrens erlaubt, ein aus diesem Stahl erzeugtes Flachprodukt im unbeschichteten oder mit einem vor Korrosion schützenden Überzug versehenen Zustand zu einem komplex geformten Bauteil, wie einem Teil einer Automobilkarosserie, zu verformen. Des Weiteren sollte auch ein Verfahren angegeben werden, dass es auf einfache Weise erlaubt, in der voranstehend genannten Weise beschaffene Flachprodukte herzustellen.Against the background of the prior art described above, the object of the invention was to develop a steel and a flat product produced therefrom which reliably has a strength of at least 950 MPa and good deformability. In addition, the steel should have a surface finish which, using a simple manufacturing process, allows a flat product produced from this steel, in the uncoated or corrosion-protective coating state, to deform into a complex shaped component, such as a part of an automobile body. Furthermore, a method should also be given that allows in a simple manner to produce in the above-mentioned manner manufactured flat products.

In Bezug auf den Werkstoff ist diese Aufgabe erfindungsgemäß durch den in Anspruch 1 angegebenen Dualphasenstahl gelöst worden. Vorteilhafte Ausgestaltungen dieses Stahls sind in den auf Anspruch 1 rückbezogenen Ansprüchen genannt.With respect to the material, this object has been achieved by the dual-phase steel specified in claim 1. Advantageous embodiments of this steel are mentioned in the dependent claims on claim 1.

Ein die voranstehend genannte Aufgabe lösendes Flachprodukt ist entsprechend Anspruch 19 erfindungsgemäß dadurch gekennzeichnet, dass es aus einem erfindungsgemäß zusammengesetzten und beschaffenen Stahl besteht.A the above-mentioned object solving flat product according to claim 19 according to the invention, characterized in that it consists of a composite according to the invention and procured steel.

In Bezug auf das Herstellverfahren ist die oben genannte Aufgabe schließlich erfindungsgemäß durch die in denWith respect to the manufacturing process, the above object is finally achieved by the invention in the

Ansprüchen 25 und 26 angegebenen Herstellweisen gelöst worden, wobei sich das in Anspruch 25 angegebene Verfahren auf die erfindungsgemäße Herstellung eines Warmbands und die in Anspruch 26 angegebene Vorgehensweise sich auf die erfindungsgemäße Herstellung eines Kaltbands beziehen. In den auf die Ansprüche 25 und 26 rückbezogenen Ansprüchen sind jeweils vorteilhafte Varianten der erfindungsgemäßen Verfahren enthalten. Zusätzlich sind nachfolgend für die praktische Anwendung der erfindungsgemäßen Verfahren und seiner in den Ansprüchen angegebenen Varianten besonders vorteilhafte Ausgestaltungen erläutert.Claims 25 and 26 specified have been solved, wherein the specified in claim 25 method on the inventive production of a hot strip and the procedure specified in claim 26 relate to the production of a cold strip according to the invention. In the claims dependent on claims 25 and 26, respectively advantageous variants of the inventive method are included. In addition, for the practical application of the method according to the invention and its variants indicated in the claims, particularly advantageous embodiments are explained below.

Ein erfindungsgemäßer Stahl zeichnet sich durch hohe Festigkeiten von mindestens 950 MPa, insbesondere mehr als 980 MPa, aus, wobei regelmäßig auch Festigkeiten von 1000 MPa und mehr erreicht werden. Gleichzeitig besitzt er eine Streckgrenze von mindestens 580 MPa, insbesondere mindestens 600 MPa, und weist eine Dehnung A80 von mindestens 10 % auf.A steel according to the invention is characterized by high strengths of at least 950 MPa, in particular more than 980 MPa, with regularities of 1000 MPa and more being achieved on a regular basis. At the same time it has a yield strength of at least 580 MPa, in particular at least 600 MPa, and has an elongation A 80 of at least 10%.

Aufgrund der Kombination aus hoher Festigkeit und guter Verformbarkeit eignet sich erfindungsgemäßer Stahl insbesondere zur Herstellung von komplex geformten, im praktischen Einsatz hoch belasteten Bauteilen, wie sie beispielsweise im Bereich des Karosseriebaus für Automobile benötigt werden.Due to the combination of high strength and good deformability, steel according to the invention is particularly suitable for the production of complex shaped, highly loaded in practical use components, such as those required in the field of bodywork for automobiles.

Dank seines Dualphasengefüges besitzt erfindungsgemäßer Stahl eine hohe Festigkeit bei gleichzeitig guter Dehnung. So ist die Legierung eines erfindungsgemäßen Stahls so zusammengesetzt , dass er einen Martensitanteil von mindestens 20 %, bevorzugt mehr als 30 %, bis maximal 70 % besitzt. Gleichzeitig können Restaustenitanteile von bis zu 8 % vorteilhaft sein, wobei in der Regel geringere Restaustenitanteile von maximal 7 % oder darunter bevorzugt werden. Der Rest des Gefüges eines erfindungsgemäßen Dualphasenstahls besteht jeweils aus Ferrit und / oder Bainit (bainitischer Ferrit + Karbide).Thanks to its dual-phase structure steel according to the invention has a high strength with good elongation at the same time. Thus, the alloy of a steel according to the invention is composed so that it has a martensite content of at least 20%, preferably more than 30%, up to a maximum of 70%. At the same time, retained austenite shares of up to 8%, with lower retained austenite contents of at most 7% or less being preferred. The remainder of the microstructure of a dual-phase steel according to the invention consists respectively of ferrite and / or bainite (bainitic ferrite + carbides).

Die hohen Festigkeiten und guten Dehnungseigenschaften sind durch die erfindungsgemäße Einstellung des Dualphasengefüges erzielt worden. Diese ist durch eine enge Auswahl der Gehalte an den einzelnen Legierungselementen ermöglicht worden, die in einem erfindungsgemäßen Stahl neben Eisen und unvermeidbaren Verunreinigungen vorhanden sind.The high strengths and good elongation properties have been achieved by the adjustment of the dual-phase structure according to the invention. This has been made possible by a narrow selection of the contents of the individual alloying elements present in a steel according to the invention besides iron and unavoidable impurities.

So sieht die Erfindung einen C-Gehalt von 0,10 - 0,20 Gew.-% vor. Der Mindestgehalt an Kohlenstoff von 0,10 Gew.-% ist dabei gewählt worden, um die Ausbildung von martensitischem Gefüge mit ausreichender Härte zu erreichen und um die gewünschte Eigenschaftskombination des erfindungsgemäßen Stahls einzustellen. Bei Gehalten von mehr als 0,20 Gew.-% behindert Kohlenstoff jedoch die Entstehung des gewünschten ferritischen / bainitischen Gefügeanteils. Auch wirken sich höhere C-Gehalte negativ auf die Schweißeignung aus, was für die Anwendung des erfindungsgemäßen Materials beispielsweise im Bereich des Automobilbaus von besonderer Bedeutung ist. Besonders sicher kann die vorteilhafte Wirkung von Kohlenstoff in einem erfindungsgemäßen Stahl dann genutzt werden, wenn der C-Gehalt eines erfindungsgemäßen Stahls 0,12 - 0,18 Gew.-%, insbesondere 0,15 - 0,16 Gew.-%, beträgt.Thus, the invention provides a C content of 0.10-0.20 wt%. The minimum content of carbon of 0.10 wt .-% has been chosen to achieve the formation of martensitic structure with sufficient hardness and to set the desired combination of properties of the steel according to the invention. However, at levels greater than 0.20% by weight, carbon hinders the formation of the desired ferritic / bainitic portion of the structure. Also, higher C contents have a negative effect on the weldability, which is of particular importance for the application of the material according to the invention, for example in the field of automotive engineering. The advantageous effect of carbon in a steel according to the invention can be used particularly reliably if the C content of a steel according to the invention is 0.12-0.18% by weight, in particular 0.15-0.16% by weight ,

Si dient in einem erfindungsgemäßen Stahl ebenfalls zur Steigerung der Festigkeit durch Härtung des Ferrits bzw. Bainits. Um diesen Effekt nutzen zu können, ist ein Mindestgehalt an Si von 0,10 Gew.-% vorgesehen, wobei die Wirkung von Si dann besonders sicher eintritt, wenn der Si-Gehalt eines erfindungsgemäßen Stahls mindestens 0,2 Gew.-%, insbesondere mindestens 0,25 Gew.-% beträgt. Im Hinblick darauf, dass ein aus einem erfindungsgemäßen Stahl erzeugtes Flachprodukt eine für die weitere Verarbeitung und erforderlichenfalls aufgetragene Beschichtungen optimale Oberflächenbeschaffenheit besitzen soll, ist gleichzeitig die Obergrenze des Si-Gehaltes auf 0,6 Gew.-% festgelegt worden. Auch ist bei Einhaltung dieser Obergrenze die Gefahr von Korngrenzoxidation minimiert. Dabei lässt sich ein ungünstiger Einfluss von Si auf die Eigenschaften des erfindungsgemäßen Stahls dadurch mit noch größerer Sicherheit vermeiden, dass der Si-Gehalt des erfindungsgemäßen Stahls auf 0,4 Gew.-%, insbesondere 0,35 Gew.-%, beschränkt wird.In a steel according to the invention, Si also serves to increase the strength by hardening the ferrite or bainite. To use this effect is a Si content of 0.10 wt .-% provided, the effect of Si is particularly safe when the Si content of a steel according to the invention is at least 0.2 wt .-%, in particular at least 0.25 wt .-% , In view of the fact that a flat product produced from a steel according to the invention should have an optimum surface finish for further processing and, if necessary, applied coatings, the upper limit of the Si content has at the same time been set at 0.6% by weight. Also, adherence to this upper limit minimizes the risk of grain boundary oxidation. In this case, an unfavorable influence of Si on the properties of the steel according to the invention can be avoided with even greater certainty that the Si content of the steel according to the invention is limited to 0.4% by weight, in particular 0.35% by weight.

Der Mn-Gehalt eines erfindungsgemäßen Stahls liegt im Bereich von 1,5 - 2,50 Gew.-%, insbesondere 1,5 - 2,35 Gew.-%, um die festigkeitssteigernde Wirkung dieses Elements zu nutzen. So wird durch die Anwesenheit von Mn die Entstehung von Martensit unterstützt. Dabei verhindern die erfindungsgemäß vorgesehenen Gehalte an Mn insbesondere im Fall, dass aus erfindungsgemäßem Stahl ein Kaltband hergestellt und dieses Kaltband abschließend geglüht wird, die Bildung von Perlit bei der Abkühlung nach dem Glühen. Diese positiven Effekte der Anwesenheit von Mn in einem erfindungsgemäßen Stahl lassen sich dann besonders sicher nutzen, wenn der Mn-Gehalt mindestens 1,7 Gew.-%, insbesondere mindestens 1,80 Gew.-% beträgt. Um jedoch einen negativen Einfluss von Mn auf die Verformbarkeit, Schweißeignung und Beschichtbarkeit zu vermeiden, ist die Obergrenze für die Gehalte an Mn auf 2,5 Gew.-% in erfindungsgemäßem Stahl gesetzt. Die möglicherweise negativen Einflüsse von Mn auf einen erfindungsgemäßen Stahl können dadurch mit erhöhter Sicherheit ausgeschlossen werden, dass der Mn-Gehalt auf 2,20 Gew.-%, insbesondere 2,00 Gew.-%, beschränkt wird.The Mn content of a steel according to the invention is in the range of 1.5-2.5% by weight, in particular 1.5-2.35% by weight, in order to utilize the strength-increasing effect of this element. Thus, the presence of Mn supports the formation of martensite. In this case, the contents of Mn provided according to the invention prevent the formation of perlite during cooling after annealing, in particular in the case where a cold strip is produced from steel according to the invention and this cold strip is finally annealed. These positive effects of the presence of Mn in a steel according to the invention can be used particularly reliably if the Mn content is at least 1.7% by weight, in particular at least 1.80% by weight. However, in order to avoid a negative influence of Mn on moldability, weldability and coatability, the upper limit of the contents of Mn is on 2.5 wt .-% set in inventive steel. The possibly negative influences of Mn on a steel according to the invention can be excluded with increased certainty that the Mn content is limited to 2.20% by weight, in particular 2.00% by weight.

Cr wirkt in einem Dualphasenstahl in Gehalten von 0,2 - 0,8 Gew.-% ebenfalls festigkeitssteigernd. Diese Wirkung tritt insbesondere dann ein, wenn der Cr-Gehalt erfindungsgemäß mindestens 0,3 Gew.-%, insbesondere mindestens 0,5 Gew.-% beträgt. Gleichzeitig ist der Cr-Gehalt eines erfindungsgemäßen Stahls jedoch auf 0,8 Gew.-% beschränkt, um die Gefahr der Entstehung von Korngrenzoxidation zu vermindern und gute Dehnungseigenschaften des erfindungsgemäßen Stahls zu sichern. Auch wird bei Einhaltung dieser Obergrenze eine Oberfläche erreicht, die gut mit einer metallischen Beschichtung versehen werden kann. Negative Einflüsse der Gehalte an Cr werden insbesondere dann vermieden, wenn die Obergrenze des Chrom-Gehalts eines erfindungsgemäßen Stahls auf höchstens 0,7 Gew.-%, insbesondere 0,6 Gew.-%, festgesetzt wird.Cr also strengthens in a dual phase steel at levels of 0.2-0.8% by weight. This effect occurs in particular when the Cr content according to the invention is at least 0.3% by weight, in particular at least 0.5% by weight. At the same time, however, the Cr content of a steel according to the invention is limited to 0.8% by weight in order to reduce the risk of grain boundary oxidation and to ensure good elongation properties of the steel according to the invention. Also, adherence to this upper limit achieves a surface that can be well provided with a metallic coating. Negative effects of the contents of Cr are avoided, in particular, if the upper limit of the chromium content of a steel according to the invention is set to not more than 0.7% by weight, in particular 0.6% by weight.

Die Anwesenheit von Titan in Gehalten von mindestens 0,02 Gew.-% trägt ebenfalls zur Steigerung der Festigkeit eines erfindungsgemäßen Stahls bei, indem es feine Ausscheidungen von TiC bzw. Ti(C,N) bildet und zur Kornfeinung beiträgt. Eine weitere positive Wirkung von Ti besteht in der Abbindung eventuell vorhandenen Stickstoffs, so dass die Bildung von Bornitriden im erfindungsgemäßen Stahl verhindert wird. Diese hätten einen stark negativen Einfluss auf die Dehnungseigenschaften und damit einhergehend auf die Umformbarkeit eines erfindungsgemäßen Flachproduktes.The presence of titanium at levels of at least 0.02% by weight also contributes to increasing the strength of a steel according to the invention by forming fine precipitates of TiC or Ti (C, N) and contributing to grain refining. Another positive effect of Ti is the setting of possibly present nitrogen, so that the formation of boron nitrides in the steel according to the invention is prevented. These would have a strong negative impact on the elongation properties and, consequently, on the formability of a flat product according to the invention.

Durch die Anwesenheit von Ti wird somit im Fall einer Zugabe von Bor zur Festigkeitssteigerung auch sichergestellt, dass das Bor seine Wirkung voll entfalten kann. Zu diesem Zweck kann es günstig sein, wenn Ti in einer Menge zugegeben wird, die mehr als das 5,1-fache des jeweiligen N-Gehaltes beträgt (d. h. Ti-Gehalt > 1,5 (3,4 x N-Gehalt)). Zu hohe Ti-Gehalte führen allerdings zu ungünstig hohen Rekristallisationstemperaturen, was sich insbesondere dann negativ auswirkt, wenn aus erfindungsgemäßem Stahl kaltgewalzte Flachprodukte erzeugt werden, die abschließend geglüht werden. Daher ist die Obergrenze des Ti-Gehalts auf 0,08 Gew.-%, insbesondere 0,06 Gew.-%, beschränkt worden. Besonders sicher lässt sich der positive Einfluss von Ti auf die Eigenschaften eines erfindungsgemäßen Stahls nutzen, wenn sein Ti-Gehalt 0,03 - 0,055 Gew.-%, insbesondere 0,040 - 0,050 Gew.-%, beträgt.The presence of Ti thus ensures, in the case of an addition of boron to increase the strength, that the boron can fully develop its effect. For this purpose, it may be favorable if Ti is added in an amount which is more than 5.1 times the respective N content (ie Ti content> 1.5 (3.4 × N content)). , However, too high Ti contents lead to unfavorably high recrystallization temperatures, which has a negative effect, in particular, when cold-rolled flat products are produced from steel according to the invention, which are finally annealed. Therefore, the upper limit of the Ti content has been limited to 0.08 wt%, especially 0.06 wt%. The positive influence of Ti on the properties of a steel according to the invention can be used particularly reliably if its Ti content is 0.03-0.055% by weight, in particular 0.040-0.050% by weight.

Auch durch die erfindungsgemäß optional vorgesehenen Gehalte an B von bis zu 0,002 Gew.-% wird die Festigkeit des erfindungsgemäßen Stahls erhöht und, wie durch die jeweilige Zugabe von Mn, Cr und Mo, im Falle der Herstellung von Kaltband aus erfindungsgemäßem Stahl die kritische Abkühlgeschwindigkeit nach dem Glühen herabgesetzt. Deshalb beträgt gemäß einer besonders praxisgerechten Ausgestaltung der Erfindung der B-Gehalt mindestens 0,0005 Gew.-%. Gleichzeitig können jedoch zu hohe Gehalte an B die Verformbarkeit des erfindungsgemäßen Stahls herabsetzen und die Ausprägung des erfindungsgemäß angestrebten Dualphasengefüges negativ beeinflussen. Optimierte Wirkungen von Bor ergeben sich in einem erfindungsgemäßen Stahl daher bei Gehalten von 0,0007 - 0,0016 Gew.-%, insbesondere 0,0008 - 0,0013 Gew.-%.The strength of the steel according to the invention is also increased by the amounts of B, which are optionally provided according to the invention, of up to 0.002% by weight and, as in the case of the addition of Mn, Cr and Mo in the case of the production of cold strip of steel according to the invention, the critical cooling rate lowered after annealing. Therefore, according to a particularly practical embodiment of the invention, the B content is at least 0.0005 wt .-%. At the same time, however, excessively high contents of B can reduce the deformability of the steel according to the invention and adversely affect the expression of the dual-phase structure desired according to the invention. Optimized effects of boron therefore result in a steel according to the invention Contents of 0.0007 - 0.0016 wt .-%, in particular 0.0008 - 0.0013 wt .-%.

Wie Bor oder Cr in den voranstehend genannten Gehaltsbereichen tragen auch die erfindungsgemäß wahlweise vorhandenen Gehalte an Molybdän zur Erhöhung der Festigkeit eines erfindungsgemäßen Stahls bei. Dabei wirkt sich die Anwesenheit von Mo erfahrungsgemäß nicht negativ auf die Beschichtbarkeit des Flachproduktes mit einer metallischen Beschichtung und seine Dehnbarkeit aus. Praktische Versuche haben gezeigt, dass sich die positiven Einflüsse von Mo bis zu Gehalten von 0,25 Gew.-%, insbesondere 0,22 Gew.-%, auch unter Kostengesichtspunkten besonders effektiv nutzen lassen. So wirken sich bereits Gehalte von 0,05 Gew.-% Mo positiv auf die Eigenschaften des erfindungsgemäßen Stahls aus. Bei Anwesenheit ausreichender Mengen an anderen festigkeitssteigernden Elementen tritt die erwünschte Wirkung von Molybdän in einem erfindungsgemäßen Stahl insbesondere dann ein, wenn sein Mo-Gehalt 0,065 - 0,18 Gew.-%, insbesondere 0,08 - 0,13 Gew.-%, beträgt. Dann jedoch, wenn Mo-Gehalte von weniger als 1,7 Gew.-% und/oder Cr-Gehalte von weniger als 0,4 Gew.-% im erfindungsgemäßen Stahl vorhanden sind, ist es vorteilhaft, zur Sicherung der geforderten Festigkeit des erfindungsgemäßen Stahls 0,05 - 0,22 Gew.-% Mo zuzugeben.Like boron or Cr in the above-mentioned content ranges, the inventively optional levels of molybdenum contribute to increasing the strength of a steel according to the invention. Experience has shown that the presence of Mo does not adversely affect the coatability of the flat product with a metallic coating and its ductility. Practical experiments have shown that the positive effects of Mo up to contents of 0.25% by weight, in particular 0.22% by weight, can be used particularly effectively, even from a cost point of view. For example, contents of 0.05% by weight Mo have a positive effect on the properties of the steel according to the invention. In the presence of sufficient amounts of other strength-enhancing elements, the desired effect of molybdenum in a steel according to the invention occurs in particular if its Mo content is 0.065-0.18% by weight, in particular 0.08-0.13% by weight, is. However, if Mo contents of less than 1.7% by weight and / or Cr contents of less than 0.4% by weight are present in the steel according to the invention, it is advantageous to secure the required strength of the invention Steel 0.05 - 0.22 wt .-% Mo added.

Aluminium wird bei der Erschmelzung eines erfindungsgemäßen Stahls zur Desoxidation und zum Abbinden von gegebenenfalls in dem Stahl enthaltenem Stickstoff genutzt. Zu diesem Zweck kann dem erfindungsgemäßen Stahl erforderlichenfalls Al in Gehalten von weniger als 0,1 Gew.-% zugegeben werden, wobei die gewünschte Wirkung von Al dann besonders sicher eintritt, wenn dessen Gehalte im Bereich von 0,01 - 0,06 Gew.-%, insbesondere 0,020 - 0,050 Gew.-%, liegen.Aluminum is used in the melting of a steel according to the invention for deoxidizing and for setting nitrogen which may be present in the steel. For this purpose, if necessary, Al may be added in amounts of less than 0.1% by weight to the steel of the present invention, with the desired effect of Al being particularly safe occurs when its contents in the range of 0.01 to 0.06 wt .-%, in particular 0.020 to 0.050 wt .-%, are.

Stickstoff ist in erfindungsgemäßem Stahl nur in Gehalten von bis zu 0,012 Gew.-% zugelassen, um insbesondere bei gleichzeitiger Anwesenheit von B die Bildung von Bornitriden zu vermeiden. Um sicher zu verhindern, dass das jeweils vorhandene Titan vollständig mit N abgebunden wird und nicht mehr als Mikrolegierungselement wirksam sein kann, ist der N-Gehalt bevorzugt auf 0,007 Gew.-% beschränkt.Nitrogen is allowed in inventive steel only in amounts of up to 0.012 wt .-%, in order to avoid the formation of boron nitrides especially in the simultaneous presence of B. In order to reliably prevent the titanium present in each case from being completely set to N and can no longer be effective as a micro-alloying element, the N content is preferably limited to 0.007% by weight.

Niedrige, unterhalb der erfindungsgemäß vorgesehenen Obergrenze liegende P-Gehalte tragen zur guten Schweißbarkeit erfindungsgemäßen Stahls bei. Daher wird der P-Gehalt erfindungsgemäß bevorzugt auf < 0,1 Gew.-%, insbesondere < 0,02 Gew.-%, beschränkt, wobei besonders gute Ergebnisse bei P-Gehalten von < 0,010 Gew.-% erzielt werden.Low P contents below the upper limit provided by the invention contribute to the good weldability of the steel according to the invention. Therefore, the P content according to the invention is preferably limited to <0.1 wt .-%, in particular <0.02 wt .-%, with particularly good results at P contents of <0.010 wt .-% can be achieved.

Bei unterhalb der erfindungsgemäß vorgegebenen Obergrenze liegenden Gehalten an Schwefel wird die Bildung von MnS bzw. (Mn,Fe)S unterdrückt, so dass eine gute Dehnbarkeit des erfindungsgemäßen Stahls bzw. der daraus hergestellten Flachprodukte gewährleistet ist. Dies ist insbesondere dann der Fall, wenn der S-Gehalt unter 0,003 Gew.-% liegt.At below the inventively given upper limit levels of sulfur, the formation of MnS or (Mn, Fe) S is suppressed, so that a good extensibility of the steel according to the invention or the flat products produced therefrom is ensured. This is especially the case when the S-content is less than 0.003 wt .-%.

In erfindungsgemäßer Weise aus einem erfindungsgemäßen Dualphasenstahl bestehende Flachprodukte können als nach dem Warmwalzen erhaltenes Warmband unmittelbar, d. h. ohne nachfolgend durchgeführten Kaltwalzprozess, der weiteren Verarbeitung zugeführt werden. So lassen sich aus erfindungsgemäß beschaffenem Warmband im unbeschichteten Zustand hoch belastbare Bauteile formen. Sollen diese Bauteile besonders gegen Korrosion geschützt werden, so können die Warmbänder vor oder nach ihrer Umformung zu dem jeweiligen Bauteil mit einem metallischen Schutzüberzug versehen werden.In accordance with the invention from a dual phase steel according to the invention existing flat products can be supplied as immediately after hot rolling hot strip, ie without subsequently performed cold rolling process, further processing. Thus, according to the invention obtained hot strip in uncoated state form highly resilient components. If these components are to be particularly protected against corrosion, then the hot strips can be provided before or after their transformation to the respective component with a metallic protective coating.

Werden dagegen Flachprodukte mit geringerer Dicke gefordert, so können die aus erfindungsgemäßem Stahl erzeugten Warmbänder zunächst einer Kaltwalzung und einer anschließenden Glühung unterzogen werden, um dann als Kaltband gegebenenfalls nach Auftrag eines metallischen, vor Korrosion schützenden Überzugs weiterverarbeitet zu werden.If, on the other hand, flat products with a smaller thickness are required, then the hot strips produced from steel according to the invention can first be subjected to cold rolling and subsequent annealing, in which case they can be further processed as cold strip, if appropriate after application of a metallic coating which protects against corrosion.

Sofern das erfindungsgemäße Flachprodukt mit einem metallischen Schutzüberzug versehen wird, kann dies beispielsweise durch Feuerverzinken, eine Galvannealing-Behandlung oder elektrolytisches Beschichten erfolgen. Erforderlichenfalls kann dabei vor dem Beschichten eine Voroxidation durchgeführt werden, um eine sichere Anbindung der metallischen Beschichtung an das jeweils zu beschichtende Substrat zu gewährleisten.If the flat product according to the invention is provided with a metallic protective coating, this can be done, for example, by hot-dip galvanizing, galvannealing or electrolytic coating. If necessary, a pre-oxidation can be carried out before the coating in order to ensure a secure connection of the metallic coating to the respective substrate to be coated.

Zur erfindungsgemäßen Herstellung eines als Warmband vorliegenden Flachprodukts mit einer Zugfestigkeit von mindestens 950 MPa sowie einer Dehnung A 80 von mindestens 10% und einem Dualphasengefüge, das zu 20 - 70 % aus Martensit, bis zu 8 % aus Restaustenit und als Rest aus Ferrit und/oder Bainit besteht, wird zunächst ein erfindungsgemäß zusammengesetzter Dualphasenstahl erschmolzen, die Schmelze zu einem Vorprodukt, wie Bramme oder Dünnbramme, vergossen, das Vorprodukt bei einer Warmwalzstarttemperatur von 1100 - 1300 °C wiedererwärmt oder gehalten, das Vorprodukt bei einer Warmwalzendtemperatur von 800 - 950 °C zu dem Warmband warmgewalzt und das erhaltene Warmband bei einer Haspeltemperatur von bis zu 570 °C gehaspelt.For the production according to the invention of a hot-rolled flat product having a tensile strength of at least 950 MPa and an elongation A 80 of at least 10% and a dual-phase structure consisting of 20-70% of martensite, up to 8% of retained austenite and the remainder of ferrite and / or bainite, a dual phase steel composed according to the invention is first melted, the melt is cast into a precursor, such as slab or thin slab, the primary product reheated or held at a hot rolling start temperature of 1100-1300 ° C, the precursor at a hot rolling end temperature of 800-950 ° C to the Hot rolled hot strip and the hot strip obtained at a reel temperature of up to 570 ° C reeled.

Durch eine geeignete Einstellung der Haspeltemperatur im Bereich von Raumtemperatur bis 570 °C lässt sich das Dualphasengefüge des als solches anschließend nicht mehr weiter gewalzten Warmbandes einstellen, um die jeweils gewünschte Eigenschaftskombination zu erhalten.By a suitable adjustment of the reel temperature in the range from room temperature to 570 ° C, the dual-phase structure of the as such subsequently no longer rolled hot strip can be adjusted to obtain the desired combination of properties.

Soll das in erfindungsgemäßer Weise erhaltene Warmband unbeschichtet bleiben oder als Warmband elektrolytisch mit einem metallischen Überzug beschichtet werden, so ist keine Glühung des Flachproduktes erforderlich. Soll dagegen das Warmband durch Feuerverzinken mit einem metallischen Überzug beschichtet werden, so wird es zunächst bei einer maximalen Glühtemperatur von 600 °C geglüht und dann auf die Temperatur des Beschichtungsbades, bei dem es sich beispielsweise um ein Zinkbad handeln kann, abgekühlt. Nach dem Durchlauf des Zinkbades kann das beschichtete Warmband in konventioneller Weise auf Raumtemperatur abgekühlt werden.If the hot strip obtained in the manner according to the invention should remain uncoated or be electrolytically coated with a metallic coating as a hot strip, no annealing of the flat product is required. If, on the other hand, the hot-rolled strip is to be coated with a metallic coating by hot-dip galvanizing, then it is first annealed at a maximum annealing temperature of 600 ° C. and then cooled to the temperature of the coating bath, which may be, for example, a zinc bath. After passing through the zinc bath, the coated hot strip can be conventionally cooled to room temperature.

Soll ein erfindungsgemäßes Flachprodukt in Form eines Kaltbandes zur Verfügung gestellt werden, so wird dazu ein erfindungsgemäß zusammengesetzter Dualphasenstahl erschmolzen, die entsprechende Stahlschmelze zu einem Vorprodukt, wie Bramme oder Dünnbramme, vergossen, das Vorprodukt bei einer Warmwalzstarttemperatur von 1100 - 1300 °C wiedererwärmt oder gehalten, das Vorprodukt bei einer Warmwalzendtemperatur von 800 - 950 °C zu einem Warmband warmgewalzt, das Warmband bei einer Haspeltemperatur von 500 - 650 °C gehaspelt, das Warmband nach dem Haspeln kaltgewalzt, das erhaltene Kaltband bei einer 700 - 900 °C betragenden Glühtemperatur geglüht und das Kaltband nach dem Glühen kontrolliert abgekühlt.If a flat product according to the invention in the form of a cold strip is to be made available, a dual phase steel composed according to the invention is melted, the corresponding molten steel is cast into a precursor, such as a slab or thin slab, and the primary product is reheated or held at a hot rolling start temperature of 1100 to 1300 ° C. , the precursor hot rolled at a hot rolling end temperature of 800 - 950 ° C to a hot strip, the hot strip at a reel temperature of 500 - 650 ° C, the cold rolled after hot rolling, the cold strip obtained at annealed at a 700-900 ° C annealing temperature and the cold strip cooled after annealing controlled.

Haspeltemperaturen im Bereich von bis zu 580 °C haben sich im Zusammenhang mit der Erzeugung von Kaltband als besonders vorteilhaft erwiesen, weil bei Überschreiten der Haspeltemperatur von 580 °C die Gefahr von Korngrenzoxidation ansteigt. Mit niedrigen Haspeltemperaturen steigt die Festigkeit und Streckgrenze des Warmbands an, so dass das Warmband immer schwerer kaltgewalzt werden kann. Dementsprechend wird das zu Kaltband kaltzuwalzende Warmband bevorzugt bei mindestens 530 °C, insbesondere mindestens 550 °C, gehaspelt.Coiling temperatures in the range of up to 580 ° C have proven to be particularly advantageous in connection with the production of cold strip, because when exceeding the coiler temperature of 580 ° C, the risk of grain boundary oxidation increases. With low reel temperatures, the strength and yield strength of the hot strip increases, so that the hot strip can be cold rolled more and more difficult. Accordingly, the cold strip to be cold rolled to cold strip is preferably at least 530 ° C, in particular at least 550 ° C, reeled.

Wenn das erfindungsgemäß erzeugte Kaltband unbeschichtet bleiben oder elektrolytisch beschichtet werden soll, so erfolgt eine Glühbehandlung in einer Conti-Glühe als separater Arbeitsschritt. Die dabei erreichten maximalen Glühtemperaturen liegen im Bereich von 700 - 900 °C bei Aufheizraten von 1 - 50 K/s. Anschließend wird das geglühte Kaltband zur gezielten Einstellung der erfindungsgemäß angestrebten Eigenschaftskombination bevorzugt in der Weise abgekühlt, dass im Temperaturbereich von 550 - 650 °C Abkühlgeschwindigkeiten von mindestens 10 K/s erreicht werden, um die Bildung von Perlit zu unterdrücken. Nach Erreichen der in diesem kritischen Temperaturbereich liegenden Temperatur kann das Band für eine Dauer von 10 - 300 s gehalten werden oder direkt mit einer Abkühlrate von 0,5 - 30 K/s auf Raumtemperatur abgekühlt werden.If the cold strip produced according to the invention remains uncoated or is to be electrolytically coated, an annealing treatment in a continuous annealing anneal takes place as a separate working step. The maximum annealing temperatures achieved are in the range of 700-900 ° C at heating rates of 1-50 K / s. Subsequently, the annealed cold strip for the targeted setting of the desired property combination according to the invention is preferably cooled in such a way that in the temperature range of 550-650 ° C cooling rates of at least 10 K / s are achieved in order to suppress the formation of perlite. After reaching the temperature lying within this critical temperature range, the strip can be held for a period of 10 to 300 s or cooled directly to room temperature at a cooling rate of 0.5 to 30 K / s.

Wenn das Kaltband jedoch durch Feuerverzinken beschichtet werden soll, dann lassen sich die Arbeitsschritte des Glühens und des Beschichtens zusammenlegen. In diesem Fall durchläuft das Kaltband in kontinuierlicher Abfolge verschiedene Ofenabschnitte einer Feuerbeschichtungsanlage, wobei in den einzelnen Ofenabschnitten unterschiedliche Temperaturen herrschen, die im Maximum im Bereich von 700 - 900 °C liegen, wobei Aufheizraten im Bereich von 2 - 100 K/s gewählt werden sollten. Nach Erreichen der jeweiligen Glühtemperatur wird das Band dann für 10 - 200 s bei dieser Temperatur gehalten. Anschließend wird das Band auf die in der Regel unter 500 °C liegende Temperatur des jeweiligen Beschichtungsbades, bei dem es sich typischerweise um ein Zinkbad handelt, abgekühlt, wobei auch in diesem Fall im Temperaturbereich von 550 - 650 °C die Abkühlgeschwindigkeit mehr als 10 K/s betragen sollte. Optional kann das Kaltband nach Erreichen dieser Temperaturstufe für 10 - 300 s bei der jeweiligen Temperatur gehalten werden. Dann läuft das geglühte Kaltband durch das jeweilige Beschichtungsbad, bei dem es sich bevorzugt um ein Zinkbad handelt. Anschließend erfolgt entweder eine Abkühlung auf Raumtemperatur, um ein konventionell feuerverzinktes Kaltband zu erhalten, oder ein schnelles Aufheizen mit anschließender Abkühlung auf Raumtemperatur, um ein Galvannealed-Kaltband herzustellen.However, if the cold strip is to be coated by hot dip galvanizing, then the steps of annealing and coating can be combined. In this case goes through the cold strip in continuous sequence different furnace sections of a fire-coating plant, wherein prevail different temperatures in the individual furnace sections, which are in the range in the range of 700 - 900 ° C, with heating rates in the range of 2 - 100 K / s should be selected. After reaching the respective annealing temperature, the strip is then held at this temperature for 10-200 seconds. The strip is then cooled to the temperature of the respective coating bath, which is typically below 500 ° C., which is typically a zinc bath, the cooling rate also being more than 10 K in the temperature range 550-650 ° C. in this case / s should be. Optionally, after reaching this temperature level, the cold strip can be held at the respective temperature for 10 - 300 s. Then the annealed cold strip passes through the respective coating bath, which is preferably a zinc bath. This is followed by either cooling to room temperature to obtain a conventionally hot-dip galvanized cold-rolled strip or rapid heating followed by cooling to room temperature to produce a galvannealed cold-rolled strip.

Wird das Warmband zu Kaltband kaltgewalzt, so hat es sich als günstig erwiesen, wenn dabei Kaltwalzgrade eingestellt werden, die 40 - 70 %, insbesondere 50 - 60 %, betragen, um unter optimaler Ausnutzung der jeweils zur Verfügung stehenden Anlagentechnik ausreichend hohe Verfestigungen des gewalzten Bandes zu erreichen. Derart kaltgewalztes erfindungsgemäßes Kaltband weist typischerweise Dicken von 0,8 - 2,5 mm auf.If the hot strip is cold rolled to cold strip, so it has proven to be favorable when doing cold rolling degrees are set, the 40-70%, in particular 50-60%, in order to achieve optimal utilization of the respective available plant technology sufficiently high solidities of the rolled Bandes to reach. Such cold-rolled cold rolled strip according to the invention typically has thicknesses of 0.8-2.5 mm.

Erforderlichenfalls kann das Kaltband im beschichteten oder unbeschichteten Zustand einer Dressierwalzung unterzogen werden, bei der im Bereich von bis zu 2 % liegende Dressiergrade eingestellt werden.If necessary, the cold-rolled strip may be in the coated or uncoated state of a temper rolling mill be subjected to be applied in which lying in the range of up to 2% lying Dressiergrade.

Nachfolgend wird die Erfindung anhand von Ausführungsbeispielen näher erläutert.The invention will be explained in more detail by means of exemplary embodiments.

Sechzehn Stahlschmelzen 1 - 16, deren Zusammensetzungen in Tabelle 1 angegeben sind und von denen die Stähle 1-6, 10, 11, 13 und 16 nicht erfindungsgemäß sind, sind in konventioneller Weise erschmolzen und zu Brammen vergossen worden. Die Brammen sind anschließend in einem Ofen auf 1200 °C wiedererwärmt und ausgehend von dieser Temperatur in konventioneller Weise warmgewalzt worden. Die Walzendtemperatur betrug dabei 900 °C.Sixteen molten steels 1-16, the compositions of which are given in Table 1 and of which the steels 1-6, 10, 11, 13 and 16 are not in accordance with the invention, have been conventionally melted and cast into slabs. The slabs were then reheated to 1200 ° C in an oven and hot rolled from this temperature in a conventional manner. The rolling end temperature was 900 ° C.

Für eine erste Versuchsreihe sind die so erhaltenen Warmbänder bei einer mit einer Genauigkeit von +/- 30°C eingestellten Haspeltemperatur von 550 °C gehaspelt worden, bevor sie mit einem Kaltwalzgrad von 50 %, 65 % bzw. 70 % zu Kaltband mit einer Dicke von 0,8 mm bis 2 mm kaltgewalzt worden sind.For a first series of tests, the hot rolled strips thus obtained were rewound at a coiler temperature of 550 ° C., adjusted to an accuracy of +/- 30 ° C., before being cold rolled to a thickness of 50%, 65% and 70%, respectively from 0.8 mm to 2 mm cold rolled.

Anschließend sind die erhaltenen Kaltbänder in der oben bereits in allgemeiner Form für ein unbeschichtet auszulieferndes Kaltband beschriebenen Weise einer Glühung und kontrollierten Abkühlung unterzogen worden.Subsequently, the cold strips obtained have been subjected to annealing and controlled cooling in the manner already described above in general form for a cold-rolled strip to be delivered uncoated.

In Tabelle 2 sind für die in der ersten Versuchsreihe aus den Schmelzen 1 bis 16 erzeugten Kaltbänder der Gefügezustand, die mechanischen Eigenschaften sowie die jeweils eingestellten Kaltwalzgrade und Banddicken angegeben.Table 2 shows the microstructural state, the mechanical properties as well as the respectively set cold rolling degrees and strip thicknesses for the cold strips produced in the first test series from melts 1 to 16.

In drei weiteren Versuchsreihen sind die aus den Schmelzen 1 bis 16 in der voranstehend beschriebenen Weise erzeugten Warmbänder bei einer weniger als 100 °C, bei einer 500 °C und bei einer 650 °C betragenden Haspeltemperatur gehaspelt worden. Die für diese Warmbänder ermittelten Eigenschaften sind in den Tabellen 3 (Haspeltemperatur 20 °C), 4 (Haspeltemperatur = 500 °C) und 5 (Haspeltemperatur = 570 °C) eingetragen. Die so erhaltenen Warmbänder waren nicht für das Kaltwalzen bestimmt, sondern sind als Warmbänder - ggf. nach Auftrag einer metallischen Schutzbeschichtung - der weiteren Verarbeitung zu Bauteilen zugeführt worden. Tabelle 1 Schmelze C Si Mn Al Mo Ti Cr B P S N 1* 0,149 0,30 1,97 0,007 - - 0,45 0,0004 0,003 0,004 0,0013 2* 0,150 0,30 1,97 <0,005 - 0,023 0,45 0,0021 0,005 0,004 0,015 3* 0,152 0,30 1,99 0,005 - - 0,46 0,0004 0,004 0,004 0,0014 4* 0,157 0,30 1,97 0,005 - - 0,81 0,0005 0,004 0,004 0,0017 5* 0,153 0,30 1,50 0,005 - - 0,81 0,0004 0,004 0,004 0,0015 6* 0,150 0,02 1,98 <0,005 - 0,023 0,80 0,0022 0,004 0,005 0,0015 7 0,152 0,60 1,97 <0,005 - 0,021 0,45 0,0022 0,004 0,004 0,0024 8 0,154 0,19 2,07 0,004 - 0,022 0,60 0,0011 0,004 0,007 0,0052 9 0,16 0,29 1,8 0,032 0,08 0,046 0,52 0,0009 0,013 0,001 0,004 10* 0,152 0,28 1,7 0,028 0,15 0,051 0,3 0,0012 0,008 0,001 0,0045 11* 0,145 0,21 1,7 0,036 0,19 0,035 0,45 0,0010 0,011 0,0015 0,0042 12 0,148 0,24 1,83 0,031 0,22 0,035 0,65 0,0012 0,010 0,0015 0,0042 13* 0,153 0,29 2,2 0,029 0,08 0,090 0,59 0,0018 0,012 0,0013 0,0051 14 0,19 0,22 1,75 0,033 0,18 0,052 0,51 0,0009 0,007 0,0020 0,0031 15 0,12 0,27 2,35 0,027 - 0,051 0,5 0,0012 0,014 0,0012 0,0029 16* 0,1 0,31 2,31 0,031 0,22 0,086 0,66 0,0016 0,013 0,0016 0,0047 Angaben in Gew.-%, Rest Eisen und unvermeidbare Verunreinigungen
* nicht erfindungsgemäß Tabelle 2 Schmelze Rp0,2 Rm A80 Gefügeanteile Kaltwalz-grad Blech-dicke [MPa] [%] Matrix Martensit [%] Bainit [%] Rest-austenit [%] Karbide [%] [mm] 1* 580 955 15,2 Ferrit 20 etwas Bainit - - 50 2,0 2* 598 1057 8,3 Ferrit 50 etwas Bainit - - 65 1,2 3* 581 970 14,9 Ferrit 30 - 40 Bainit - Karbide 50 2,0 4* 590 1023 12,5 Ferrit 20 - 0 10 Karbide 70 0,8 5* 585 960 17,1 Ferrit 20 - - Karbide 50 2,0 6* 601 997 8,6 Bainit 50 - - Karbide 50 2,0 7 607 1038 10,8 Bainit + 10% Ferrit 50 - - Karbide 70 0,8 8 602 992 14 Bainit 40 - 45 - 6,5 - 50 2,0 9 645 1071 14,8 Ferrit 50 - 60 - 2,5 - 50 2,0 10* 635 1054 15,1 Ferrit 45 - 2,0 - 70 0,8 11* 618 1035 15,3 Ferrit 30 - 40 - 1 - 65 1,2 12 626 1047 14,2 Ferrit / Bainit 40 - 50 - - - 70 0,8 13* 675 1102 10,5 Bainit / Ferrit 60 - 70 - - - 50 2,0 14 609 1031 15,4 Ferrit 35 - 45 - 3 - 50 2,0 15 612 1010 11,3 Ferrit 40 - 1,5 - 65 1,2 16* 603 1016 13,6 Ferrit 55 - 65 - 3 - 65 1,2 * nicht erfindungsgemäß Tabelle 3 Schmelze Rp0,2 Rm A80 Gefügeanteile [MPa] [MPa] [%] Matrix Martensit [%] 1* 580 950 12,3 Bainit / Ferrit 20 2* 621 1023 11,5 Bainit 20 - 30 3* 614 985 13,4 Bainit / Ferrit 25 - 30 4* 639 1012 12,9 Bainit 25 5* 580 950 14,5 Bainit 20 6* 725 996 13,7 Bainit 25 7 594 998 13,5 Bainit 20 - 30 8 731 1005 13,9 Bainit 25 - 35 9 1070 1129 12,1 Bainit 45 - 55 10* 642 1014 13,4 Bainit 30 - 35 11* 626 1007 14,8 Bainit 25 - 35 12 640 1017 15,7 Bainit 20 - 30 13* 854 1121 10,7 Bainit 60 - 70 14 674 1014 12,8 Bainit 25 - 35 15 685 1027 12,7 Bainit 35 - 45 16* 691 1031 13,8 Bainit 30 - 40 * nicht erfindungsgemäß Tabelle 4 Schmelze Rp0,2 Rm A80 Gefügeanteile [MPa] [MPa] [%] Matrix Martensit [%] Restaustenit [%] 1* 580 950 14 Bainit / Ferrit 20 - 2* 600 985 12 Bainit 25 3 3* 630 970 14 Bainit / Ferrit 20 1 4* 580 950 15 Bainit / Ferrit 25 5,5 5* 600 1005 15,2 Bainit 25 < 1 6* 642 1012 12,1 Bainit 20 1 7 585 970 13,8 Bainit 20 - 25 5,5 8 855 1002 13 Bainit 20 3 9 801 1079 10,6 Bainit 20 - 25 2,5 10* 634 970 13 Bainit / Ferrit 20 3,5 11* 671 954 14,2 Bainit 20 3 12 678 1021 10,6 Bainit 30 1 13* 716 1069 11,8 Bainit 25 - 30 6 14 681 1012 13,2 Bainit / Ferrit 35 3 15 706 1010 13,1 Bainit 30 1 16* 724 986 15,6 Bainit 30 5 * nicht erfindungsgemäß Tabelle 5 Schmelze Rp0,2 Rm A80 Gefügeanteile [MPa] [MPa] [%] Matrix Martensit [%] Restaustenit [%] 1* 580 950 13 Ferrit 20 - 2* 590 980 13,6 Ferrit / Bainit 20 6 3* 610 965 15,8 Ferrit 20 - 4* 580 950 17,2 Ferrit / Bainit 25 3 5* 585 995 18,4 Ferrit 20 - 6* 580 1003 16,4 Ferrit / Bainit 20 4 7 590 960 15,9 Ferrit / Bainit 35 3 8 654 1003 15 Ferrit / Bainit 30 3 9 618 1006 15,4 Ferrit / Bainit 30 8 10* 580 940 17,1 Ferrit / Bainit 25 6 11* 595 911 18,4 Ferrit / Bainit 25 6 12 641 1011 13,7 Bainit / Ferrit 30 2 13* 698 1021 13,4 Bainit 35 6 14 585 921 16,7 Ferrit / Bainit 25 5 15 712 1001 15,4 Bainit / Ferrit 30 7 16* 722 1015 16,3 Bainit / Ferrit 35 2 * nicht erfindungsgemäß In three further series of experiments are those of the melts 1 to 16 in the above Wound hot strip produced at less than 100 ° C, coiled at 500 ° C and at 650 ° C reel temperature. The properties determined for these hot strips are given in Tables 3 (reel temperature 20 ° C), 4 (reel temperature = 500 ° C) and 5 (reel temperature = 570 ° C). The hot strips thus obtained were not intended for cold rolling, but have been supplied as hot strips - possibly after application of a metallic protective coating - the further processing to components. Table 1 melt C Si Mn al Not a word Ti Cr B P S N 1* 0,149 0.30 1.97 0,007 - - 0.45 0.0004 0,003 0,004 0.0013 2 * 0,150 0.30 1.97 <0.005 - 0.023 0.45 0.0021 0.005 0,004 0,015 3 * 0,152 0.30 1.99 0.005 - - 0.46 0.0004 0,004 0,004 0.0014 4 * 0,157 0.30 1.97 0.005 - - 0.81 0.0005 0,004 0,004 0.0017 5 * 0.153 0.30 1.50 0.005 - - 0.81 0.0004 0,004 0,004 0.0015 6 * 0,150 0.02 1.98 <0.005 - 0.023 0.80 0.0022 0,004 0.005 0.0015 7 0,152 0.60 1.97 <0.005 - 0,021 0.45 0.0022 0,004 0,004 0.0024 8th 0.154 0.19 2.07 0,004 - 0,022 0.60 0.0011 0,004 0,007 0.0052 9 0.16 0.29 1.8 0.032 0.08 0.046 0.52 0.0009 0,013 0.001 0,004 10 * 0,152 0.28 1.7 0.028 0.15 0,051 0.3 0.0012 0,008 0.001 0.0045 11 * 0.145 0.21 1.7 0,036 0.19 0,035 0.45 0.0010 0.011 0.0015 0.0042 12 0.148 0.24 1.83 0.031 0.22 0,035 0.65 0.0012 0,010 0.0015 0.0042 13 * 0.153 0.29 2.2 0,029 0.08 0,090 0.59 0.0018 0,012 0.0013 0.0051 14 0.19 0.22 1.75 0.033 0.18 0,052 0.51 0.0009 0,007 0.0020 0.0031 15 0.12 0.27 2.35 0.027 - 0,051 0.5 0.0012 0,014 0.0012 0.0029 16. * 0.1 0.31 2.31 0.031 0.22 0.086 0.66 0.0016 0,013 0.0016 0.0047 Data in wt .-%, balance iron and unavoidable impurities
* not according to the invention melt R p0,2 R m A 80 portion of structure Cold rolling degree Sheet thickness [MPa] [%] matrix Martensite [%] Bainite [%] Residual austenite [%] carbides [%] [Mm] 1* 580 955 15.2 ferrite 20 something bainite - - 50 2.0 2 * 598 1057 8.3 ferrite 50 something bainite - - 65 1.2 3 * 581 970 14.9 ferrite 30 - 40 bainit - carbides 50 2.0 4 * 590 1023 12.5 ferrite 20 - 0 10 carbides 70 0.8 5 * 585 960 17.1 ferrite 20 - - carbides 50 2.0 6 * 601 997 8.6 bainit 50 - - carbides 50 2.0 7 607 1038 10.8 Bainite + 10% ferrite 50 - - carbides 70 0.8 8th 602 992 14 bainit 40 - 45 - 6.5 - 50 2.0 9 645 1071 14.8 ferrite 50 - 60 - 2.5 - 50 2.0 10 * 635 1054 15.1 ferrite 45 - 2.0 - 70 0.8 11 * 618 1035 15.3 ferrite 30 - 40 - 1 - 65 1.2 12 626 1047 14.2 Ferrite / bainite 40 - 50 - - - 70 0.8 13 * 675 1102 10.5 Bainite / ferrite 60 - 70 - - - 50 2.0 14 609 1031 15.4 ferrite 35 - 45 - 3 - 50 2.0 15 612 1010 11.3 ferrite 40 - 1.5 - 65 1.2 16. * 603 1016 13.6 ferrite 55 - 65 - 3 - 65 1.2 * not according to the invention melt R p0,2 R m A 80 portion of structure [MPa] [MPa] [%] matrix Martensite [%] 1* 580 950 12.3 Bainite / ferrite 20 2 * 621 1023 11.5 bainit 20 - 30 3 * 614 985 13.4 Bainite / ferrite 25 - 30 4 * 639 1012 12.9 bainit 25 5 * 580 950 14.5 bainit 20 6 * 725 996 13.7 bainit 25 7 594 998 13.5 bainit 20 - 30 8th 731 1005 13.9 bainit 25 - 35 9 1070 1129 12.1 bainit 45 - 55 10 * 642 1014 13.4 bainit 30 - 35 11 * 626 1007 14.8 bainit 25 - 35 12 640 1017 15.7 bainit 20 - 30 13 * 854 1121 10.7 bainit 60 - 70 14 674 1014 12.8 bainit 25 - 35 15 685 1027 12.7 bainit 35 - 45 16. * 691 1031 13.8 bainit 30 - 40 * not according to the invention melt R p0,2 R m A 80 portion of structure [MPa] [MPa] [%] matrix Martensite [%] Retained austenite [%] 1* 580 950 14 Bainite / ferrite 20 - 2 * 600 985 12 bainite 25 3 3 * 630 970 14 Bainite / ferrite 20 1 4 * 580 950 15 Bainite / ferrite 25 5.5 5 * 600 1005 15.2 bainit 25 <1 6 * 642 1012 12.1 bainit 20 1 7 585 970 13.8 bainit 20 - 25 5.5 8th 855 1002 13 bainit 20 3 9 801 1079 10.6 bainit 20 - 25 2.5 10 * 634 970 13 Bainite / ferrite 20 3.5 11 * 671 954 14.2 bainit 20 3 12 678 1021 10.6 bainit 30 1 13 * 716 1069 11.8 bainit 25 - 30 6 14 681 1012 13.2 Bainite / ferrite 35 3 15 706 1010 13.1 bainit 30 1 16. * 724 986 15.6 bainit 30 5 * not according to the invention melt R p0,2 R m A 80 portion of structure [MPa] [MPa] [%] matrix Martensite [%] Retained austenite [%] 1* 580 950 13 ferrite 20 - 2 * 590 980 13.6 Ferrite / bainite 20 6 3 * 610 965 15.8 ferrite 20 - 4 * 580 950 17.2 Ferrite / bainite 25 3 5 * 585 995 18.4 ferrite 20 - 6 * 580 1003 16.4 Ferrite / bainite 20 4 7 590 960 15.9 Ferrite / bainite 35 3 8th 654 1003 15 Ferrite / bainite 30 3 9 618 1006 15.4 Ferrite / bainite 30 8th 10 * 580 940 17.1 Ferrite / bainite 25 6 11 * 595 911 18.4 Ferrite / bainite 25 6 12 641 1011 13.7 Bainite / ferrite 30 2 13 * 698 1021 13.4 bainit 35 6 14 585 921 16.7 Ferrite / bainite 25 5 15 712 1001 15.4 Bainite / ferrite 30 7 16. * 722 1015 16.3 Bainite / ferrite 35 2 * not according to the invention

Claims (28)

  1. Dual-phase steel, the structure of which consists to 20 - 70 % of martensite, up to 8 % of retained austenite and for the remainder of ferrite and/or bainite and which has a tensile strength of at least 950 MPa and an elongation A80 of at least 10%, with the following composition (in % by weight): C: 0.10 - 0.20 %, Si: 0.10 - 0.60 %, Mn: 1.50 - 2.50 %, Cr: 0.30 - 0.70 %, Ti: 0.02 - 0.08 %, B: < 0.0020 %, Mo : < 0.25 %, Al : < 0.10 %, P : ≤ 0.2 %, S : ≤ 0.01 %, N : ≤ 0.012 %
    the remainder being iron and unavoidable impurities.
  2. Dual-phase steel according to claim 1, characterised in that the yield strength thereof is at least 580 MPa.
  3. Dual-phase steel according to any one of the preceding claims, characterised in that the P content thereof is < 0.1 % by weight, in particular < 0.02 % by weight.
  4. Dual-phase steel according to any one of the preceding claims, characterised in that the C content thereof is from 0.12 to 0.18 % by weight.
  5. Dual-phase steel according to any one of the preceding claims, characterised in that the Si content thereof is from 0.20 to 0.40 % by weight.
  6. Dual-phase steel according to any one of the preceding claims, characterised in that the Mn content thereof is from 1.50 to 2.35 % by weight.
  7. Dual-phase steel according to any one of the preceding claims, characterised in that the Ti content thereof is from 0.030 to 0.055 % by weight.
  8. Dual-phase steel according to any one of the preceding claims, characterised in that in the presence of N, the Ti content of said dual-phase steel is more than 5.1 times greater than the respective N content.
  9. Dual-phase steel according to any one of the preceding claims, characterised in that the B content thereof is from 0.0005 to 0.0020 % by weight.
  10. Dual-phase steel according to claim 9, characterised in that the B content thereof is from 0.0007 to 0.0016 % by weight.
  11. Dual-phase steel according to any one of the preceding claims, characterised in that the Mo content thereof is from 0.05 to 0.22 % by weight.
  12. Dual-phase steel according to claim 11, characterised in that the Mn content thereof is < 1.7 % by weight.
  13. Dual-phase steel according to either claim 11 or claim 12, characterised in that the Cr content thereof is < 0.4 % by weight.
  14. Dual-phase steel according to any one of the preceding claims, characterised in that the Mo content thereof is from 0.065 to 0.150 % by weight.
  15. Dual-phase steel according to any one of the preceding claims, characterised in that the Al content thereof is from 0.01 to 0.06 % by weight.
  16. Dual-phase steel according to any one of the preceding claims, characterised in that the S content thereof is < 0.003 % by weight.
  17. Dual-phase steel according to any one of the preceding claims, characterised in that the N content thereof is < 0.007 % by weight.
  18. Dual-phase steel according to any one of the preceding claims, characterised in that the retained austenite content thereof is less than 7 %.
  19. Flat product consisting of a dual-phase steel obtained according to any one of claims 1 to 18.
  20. Flat product according to claim 19, characterised in that it is a hot strip which has only been hot-rolled.
  21. Flat product according to claim 19, characterised in that it is a cold strip obtained by cold rolling.
  22. Flat product according to any one of claims 19 to 21, characterised in that it is provided with a protective metallic coating.
  23. Flat product according to claim 22, characterised in that the protective metallic coating is produced by hot-dip galvanisation.
  24. Flat product according to claim 22, characterised in that the protective metallic coating is produced by galvannealing.
  25. Process for the production of a hot strip having a tensile strength of at least 950 MPa and an elongation A80 of at least 10% and a dual-phase structure which consists to 20 - 70 % of martensite, up to 8 % of retained austenite and for the remainder of ferrite and/or bainite, comprising the following steps:
    - melting a dual-phase steel obtained according to any one of claims 1 to 18,
    - casting the melt into a pre-product, such as slab or thin slab,
    - reheating to or keeping the pre-product at a starting hot rolling temperature of 1100 - 1300 °C,
    - hot rolling the pre-product at a final hot rolling temperature of 800 - 950 °C into the hot strip, and
    - reeling the hot strip at a reeling temperature of up to 570 °C.
  26. Process for the production of a cold strip having a tensile strength of at least 950 MPa and an elongation A80 of at least 10 % and a dual-phase structure which consists to 20 - 70 % of martensite, up to 8 % of retained austenite and for the remainder of ferrite and/or bainite, comprising the following steps:
    - melting a dual-phase steel composed according to any one of claims 1 to 18,
    - casting the melt into a pre-product, such as slab or thin slab,
    - reheating to or keeping the pre-product at a starting hot rolling temperature of 1100 - 1300 °C,
    - hot rolling the pre-product at a final hot rolling temperature of 800 - 950 °C into a hot strip,
    - reeling the hot strip at a reeling temperature of 500 - 650 °C,
    - cold-rolling the hot strip after reeling,
    - annealing the cold strip at an annealing temperature of 700 - 900 °C, and
    - cooling the annealed cold strip in a controlled manner.
  27. Process according to claim 26, characterised in that the hot strip is cold-rolled into a cold strip with a degree of cold-rolling of from 40 to 70 %.
  28. Process according to either claim 26 or claim 27, characterised in that the controlled cooling is carried out within a temperature range of from 550 to 650 °C at a cooling rate of at least 10 K/s.
EP07114398A 2007-08-15 2007-08-15 Dual-phase steel, flat product made of such dual-phase steel and method for manufacturing a flat product Active EP2028282B1 (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
PL07114398T PL2028282T3 (en) 2007-08-15 2007-08-15 Dual-phase steel, flat product made of such dual-phase steel and method for manufacturing a flat product
ES07114398T ES2387040T3 (en) 2007-08-15 2007-08-15 Double phase steel, flat product of a double phase steel of this type and process for manufacturing a flat product
EP07114398A EP2028282B1 (en) 2007-08-15 2007-08-15 Dual-phase steel, flat product made of such dual-phase steel and method for manufacturing a flat product
CN2008801034262A CN101802233B (en) 2007-08-15 2008-08-07 Dual-phase steel, flat product made of such dual-phase steel and method for producing flat product
US12/673,388 US20100273024A1 (en) 2007-08-15 2008-08-07 Dual-phase steel, flat product made of a dual-phase steel of this type and processes for the production of a flat product
PCT/EP2008/060381 WO2009021897A1 (en) 2007-08-15 2008-08-07 Dual-phase steel, flat product made of such dual-phase steel and method for producing a flat product
JP2010520536A JP5486496B2 (en) 2007-08-15 2008-08-07 Dual-phase steel, flat products made of this type of dual-phase steel and methods for producing flat products

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Families Citing this family (46)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20100034118A (en) * 2008-09-23 2010-04-01 포항공과대학교 산학협력단 Hot-dip galvanized steel sheet having a martensitic structure with ultimate high strength and method for manufacturing the same
EP2383353B1 (en) 2010-04-30 2019-11-06 ThyssenKrupp Steel Europe AG High tensile steel containing Mn, steel surface product made from such steel and method for producing same
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DE102012002079B4 (en) * 2012-01-30 2015-05-13 Salzgitter Flachstahl Gmbh Process for producing a cold or hot rolled steel strip from a high strength multiphase steel
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CN104520448B (en) * 2012-06-05 2017-08-11 蒂森克虏伯钢铁欧洲股份公司 The manufacture method of steel, flat product and the flat product
PL2684975T3 (en) * 2012-07-10 2017-08-31 Thyssenkrupp Steel Europe Ag Cold rolled steel flat product and method for its production
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CN103060703B (en) * 2013-01-22 2015-09-23 宝山钢铁股份有限公司 A kind of cold rolling diphasic strip steel of 780MPa level and manufacture method thereof
JP6291289B2 (en) * 2013-03-06 2018-03-14 株式会社神戸製鋼所 High-strength cold-rolled steel sheet excellent in steel sheet shape and shape freezing property and method for producing the same
MX2016016129A (en) * 2014-06-06 2017-03-28 Arcelormittal High strength multiphase galvanized steel sheet, production method and use.
WO2016001700A1 (en) 2014-07-03 2016-01-07 Arcelormittal Method for producing a high strength steel sheet having improved strength, ductility and formability
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CN104264056B (en) * 2014-09-16 2017-01-18 河北钢铁股份有限公司唐山分公司 800-MPa medium-carbon high-silicon cold-rolled galvanized sheet and preparation method thereof
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DE102021119047A1 (en) 2021-07-22 2023-01-26 Thyssenkrupp Steel Europe Ag Method for producing a cold-rolled flat steel product with a bainitic matrix and cold-rolled flat steel product with a bainitic matrix
CN114959482B (en) * 2022-05-31 2023-05-30 山东钢铁集团日照有限公司 Multipurpose 800 MPa-grade dual-phase steel and regulating and controlling method thereof
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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0966547B1 (en) * 1997-03-13 2001-10-04 Thyssen Krupp Stahl AG Method for producing a highly resistant, very ductile steel strip

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000282175A (en) * 1999-04-02 2000-10-10 Kawasaki Steel Corp Superhigh strength hot-rolled steel sheet excellent in workability, and its production
DE19936151A1 (en) * 1999-07-31 2001-02-08 Thyssenkrupp Stahl Ag High-strength steel strip or sheet and process for its manufacture
FR2833617B1 (en) 2001-12-14 2004-08-20 Usinor METHOD FOR MANUFACTURING VERY HIGH STRENGTH COLD ROLLED SHEET OF MICRO-ALLOY DUAL STEEL
JP4167587B2 (en) * 2003-02-28 2008-10-15 新日本製鐵株式会社 High-strength steel sheet excellent in hydrogen embrittlement resistance and method for producing the same
JP4649868B2 (en) * 2003-04-21 2011-03-16 Ｊｆｅスチール株式会社 High strength hot rolled steel sheet and method for producing the same
FR2855184B1 (en) * 2003-05-19 2006-05-19 Usinor COLD LAMINATED, ALUMINATED, HIGH STRENGTH, DUAL PHASE STEEL FOR TELEVISION ANTI-IMPLOSION BELT, AND METHOD FOR MANUFACTURING THE SAME
JP3934604B2 (en) * 2003-12-25 2007-06-20 株式会社神戸製鋼所 High strength cold-rolled steel sheet with excellent coating adhesion
US20070144633A1 (en) * 2004-03-31 2007-06-28 Taro Kizu High-stiffness high-strength thin steel sheet and method for producing the same
JP4445365B2 (en) * 2004-10-06 2010-04-07 新日本製鐵株式会社 Manufacturing method of high-strength thin steel sheet with excellent elongation and hole expandability

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0966547B1 (en) * 1997-03-13 2001-10-04 Thyssen Krupp Stahl AG Method for producing a highly resistant, very ductile steel strip

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ES2387040T3 (en) 2012-09-12
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JP2010535946A (en) 2010-11-25
CN101802233B (en) 2013-08-14
CN101802233A (en) 2010-08-11
US20100273024A1 (en) 2010-10-28
WO2009021897A1 (en) 2009-02-19
EP2028282A1 (en) 2009-02-25

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