EP2439290B1 - Multiphase steel, cold rolled flat product produced from this multiphase steel and method for producing same - Google Patents

Multiphase steel, cold rolled flat product produced from this multiphase steel and method for producing same Download PDF

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Publication number
EP2439290B1
EP2439290B1 EP10186553.3A EP10186553A EP2439290B1 EP 2439290 B1 EP2439290 B1 EP 2439290B1 EP 10186553 A EP10186553 A EP 10186553A EP 2439290 B1 EP2439290 B1 EP 2439290B1
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EP
European Patent Office
Prior art keywords
phase steel
cold
annealing
content
steel
Prior art date
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Application number
EP10186553.3A
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German (de)
French (fr)
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EP2439290A1 (en
Inventor
Dr. Ekaterina Bocharova
Dr. Dorothea Mattissen
Dr. Roland Sebald
Dr. Daniel Krizan
Dr. Andreas Pichler
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Voestalpine Stahl GmbH
ThyssenKrupp Steel Europe AG
Original Assignee
Voestalpine Stahl GmbH
ThyssenKrupp Steel Europe AG
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Publication date
Application filed by Voestalpine Stahl GmbH, ThyssenKrupp Steel Europe AG filed Critical Voestalpine Stahl GmbH
Priority to EP10186553.3A priority Critical patent/EP2439290B1/en
Priority to PCT/EP2011/066522 priority patent/WO2012045595A1/en
Priority to US13/877,782 priority patent/US9970088B2/en
Priority to KR1020137011457A priority patent/KR101848876B1/en
Priority to JP2013532112A priority patent/JP6001541B2/en
Priority to CN201180048744.5A priority patent/CN103210097B/en
Publication of EP2439290A1 publication Critical patent/EP2439290A1/en
Application granted granted Critical
Publication of EP2439290B1 publication Critical patent/EP2439290B1/en
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Classifications

    • 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
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/005—Heat treatment of ferrous alloys containing Mn
    • 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
    • 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
    • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
    • 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
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • 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
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • 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
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • 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
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • 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
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/001—Austenite
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/002—Bainite
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/008—Martensite

Definitions

  • the invention relates to a multiphase steel, a Kaltwalzflach etc. produced by such a multi-phase steel by cold rolling and a process for its preparation.
  • the "flat products” according to the invention may be sheets, strips, blanks obtained therefrom or comparable products. If this is referred to as "cold flat products", it means flat products produced by cold rolling.
  • a multiphase steel which should have a balanced property profile in this respect, is from the EP 1 367 143 A1 known. In addition to a comparable high strength and good ductility of the known steel should also have a particularly good weldability.
  • the known steel contains to 0.03 - 0.25 wt .-% C, by its presence in combination with the other alloying elements tensile strengths of at least 700 MPa to be achieved.
  • the strength of the known steel is to be supported by Mn in contents of 1.4-3.5% by weight.
  • Al is used in the melting of the known steel as the oxidizing agent and may be present in the steel in amounts of up to 0.1% by weight.
  • the known steel may also have up to 0.7% by weight of Si, the presence of which stabilizes the ferritic-martensitic structure of the steel.
  • Cr is added to the known steel in amounts of 0.05-1% by weight in order to reduce the influence of the heat introduced by the welding process in the region of the weld.
  • Nb should additionally have a positive influence on the deformability of the steel, since its presence brings about a thinning of the ferrite grain.
  • 0.05 to 1% by weight of Mo, 0.02 to 0.5% by weight of V, 0.005 to 0.05% by weight of Ti and 0.0002 to 0.002% by weight of the known steel can be used.
  • % B are added. Mo and V contribute to the hardenability of the known steel, while Ti and B should additionally have a positive effect on the strength of the steel.
  • Another, also made of a high strength multiphase steel, well malleable steel sheet is from the EP 1 589 126 B1 known.
  • This known steel sheet contains 0.10-0.28 wt% C, 1.0-2.0 wt% Si, 1.0-3.0 wt% Mn, 0.03-0.10 Wt% Nb, up to 0.5 wt% Al, up to 0.15 wt% P, up to 0.02 wt% S.
  • the steel sheet up to 1.0 wt% Mo, up to 0.5 wt% Ni, up to 0.5 wt% Cu, to 0.003 wt% Ca, up to 0.003 Wt .-% rare earth metals, up to 0.1 wt .-% Ti or up to 0.1 wt .-% V be present.
  • the structure of the known steel sheet based on its overall structure, has a retained austenite content of 5 to 20% and at least 50% bainitic ferrite.
  • the proportion of polygonal ferrite in the structure of the known steel sheet should be at most 30%.
  • the proportion of polygonal ferrite in the known steel sheet bainite to form the matrix phase and Restautenit shares be present, which contribute to the balance of tensile strength and ductility.
  • the presence of Nb should ensure that the retained austenite content of the microstructure is fine-grained.
  • this is also a final annealing at temperatures above the Ac 3 temperature, followed by controlled cooling with a Cooling rate of at least 10 ° C / s up to a lying in the range of 300 - 450 ° C temperature at which the bainite transformation is completed, and finally a holding at this temperature for a sufficiently long time may be required.
  • the flat steel product has in addition to iron and unavoidable impurities (in% by mass) 0.06 - 0.6% C, 1 - 6% Mn, 0.1 - 2% Si and 0.01 - 3% Al, wherein for the contents of Si and Mn should satisfy the condition Si / Mn ⁇ 0.40.
  • the flat steel product may be 0.005 - 0.1% Nb, up to 0.02% S, 0.0005 - 0.1% P, up to 0.01% N, 0.005 - 0.1% Ti, 0.0003 - 0.01% B and 0.005 - 0.1% V contained.
  • the structure of the flat steel product should have at least 75% bainitic ferrite and polygonal ferrite and at least 3% retained austenite, the proportion of the polygonal ferrite being 1-50% and the proportion of bainitic ferrite being at least 40%.
  • the microstructure may also contain at least 75% tempered martensite and ferrite and at least 3% retained austenite, in which case the proportion of ferrite should be 4-40% and the proportion of martensite at least 50%.
  • the flat steel product undergoes hot rolling followed by surface and heat treatment, with specially adapted temperature specifications Need to become. In this way, not only the desired surface texture, but also the formation of cracks during forming should be avoided.
  • the object of the invention was to further increase a multiphase steel To provide strength, which also has a high elongation at break.
  • a flat product with a further optimized combination of high strength and good ductility and a method for producing such a flat product should be specified.
  • the solution of the above-mentioned object consists of a cold flat product designed according to claim 11.
  • a multiphase steel according to the invention contains (in% by weight) C: 0.14-0.25%, Mn: 1, 7-2.5%, Si: 0.2-0.7%, Al: 0.5- 1, 5%, Cr: ⁇ 0.1%, Mo: ⁇ 0.05%, Nb: 0.02-0.06%, S: up to 0.01%, in particular up to 0.005%, P: to to 0.02%, N: up to 0.01%, and optionally at least one element from the group "Ti, B, V", and the balance iron and unavoidable impurities, wherein for the contents of the optionally provided elements are provided such that Ti: ⁇ 0.1%, B: ⁇ 0.002%, V: ⁇ 0.15% and wherein in the structure of the steel at least 10% by volume of ferrite and at least 6% by volume. % Retained austenite are present.
  • a steel assembled and obtained according to the invention achieves a tensile strength R m of at least 950 MPa, a yield strength R eL of at least 500 MPa and an elongation at break A 80 in the transverse direction of at least 15%.
  • Carbon increases the amount and stability of retained austenite. Therefore, in the steel of the present invention, at least 0.14 wt% of carbon is present to stabilize the austenite to room temperature and to prevent complete conversion of the austenite formed in an annealing treatment into martensite, ferrite or bainite, and bainitic ferrite, respectively. However, over 0.25 wt .-% lying carbon contents have a negative effect on the weldability.
  • Mn Like C, Mn contributes to the strength and increase the amount and stability of the retained austenite. However, excessive Mn levels increase the risk of segregation. They also have a negative effect on the elongation at break, since the ferrite and bainite conversions are greatly delayed and, as a result, comparatively high amounts of martensite remain in the microstructure.
  • the Mn content of a steel according to the invention is set at 1.7-2.5% by weight.
  • Al are present in amounts of 0.5-1.5% by weight and Si in contents of 0.2-0.7% by weight. present in order to avoid carbide formation in the bainite step in the over-aging treatment carried out in the course of the inventive processing of the steel.
  • the bainite transformation does not proceed completely due to the presence of Al and Si, so that only bainitic ferrite is formed and carbide formation does not occur. In this way, the present invention desired stability of carbon-enriched retained austenite is achieved.
  • This effect can be ensured particularly reliably by limiting the Si content to 0.6% by weight or the Al content to 0.7-1.4% by weight, with Si contents of more than are set as 0.2 wt .-% and less than 0.6 wt .-% and the Al contents between 0.7 wt .-% and 1.4 wt .-% are.
  • Si contents of more than are set as 0.2 wt .-% and less than 0.6 wt .-% and the Al contents between 0.7 wt .-% and 1.4 wt .-% are.
  • optimum properties of the multiphase steel according to the invention result when the sum of its Al and Si contents is 1.2-2.0% by weight.
  • the Cr content is limited to less than 0.1% by weight and the Mo content of a steel according to the invention to less than 0.05% by weight, in particular less than 0.01% by weight.
  • a steel according to the invention contains Nb in amounts of 0.02-0.06% by weight and optionally one or more of the elements "Ti, V, B" in order to increase the strength of the steel steel according to the invention.
  • Nb, Ti, V and B form very fine precipitates with the C and N present in the steel according to the invention. These precipitates increase strength and yield strength by particle hardening and grain refining. The grain refining is also of great advantage for the forming properties of the steel.
  • Ti still binds N during solidification or at very high temperatures, so that possible negative effects of this element on the properties of the steel according to the invention are reduced to a minimum.
  • up to 0.1% by weight of Ti and up to 0.15% by weight of V can be added to a steel according to the invention in addition to the ever present Nb.
  • the positive influence of the presence of Ti with respect to the setting of the N content can be used particularly purposefully if the Ti content "% Ti" of a multiphase steel according to the invention fulfills the following condition [3]: % Ti ⁇ 3 . 4 x % N . where "% N" denotes the respective N content of the multiphase steel and this condition is to be observed, in particular, when the Ti content is 0.01-0.03 wt%.
  • the positive effect of Ti in a steel according to the invention occurs particularly reliably when its Ti content is at least 0.01% by weight.
  • the ferrite formation can be delayed upon cooling, so that a larger amount of austenite is present in the bainite. As a result, the amount and the stability of the retained austenite can be increased.
  • bainitic ferrite is formed instead of normal ferrite, which contributes to increasing the yield strength.
  • At least 10% by volume of ferrite, in particular at least 12% by volume of ferrite, and at least 6% by volume of retained austenite are present in the structure of a steel according to the invention, in order to ensure the desired high strength on the one hand and good ductility on the other hand.
  • up to 90% by volume of the microstructure can be used for this purpose Ferrite and up to 20 vol .-% consist of retained austenite.
  • Contents of at least 5 vol.% Martensite in the structure of the steel according to the invention contribute to its strength, wherein the martensite content to max. 40 vol .-% should be limited to ensure sufficient extensibility of the steel according to the invention.
  • optionally 5 to 40% by volume of bainite can be present in the microstructure of a steel according to the invention.
  • the retained austenite of a steel according to the invention is enriched with carbon in such a way that its content is as described in the article of A. Zarei Hanzaki et al. in ISIJ Int. Vol. 35, No 3, 1995, pp. 324 - 331 published formula [1] calculated C inRA content is more than 0.6 wt .-%.
  • C INRA a RA - a ⁇ / 0 . 0044 with a ⁇ : 0.3578 nm (lattice constant of austenite); a RA : respective lattice parameter of the retained austenite after final cooling in nm measured on the finished cold strip.
  • the amount of carbon present in the retained austenite substantially affects the TRIP properties and ductility of a steel according to the invention. Accordingly, it is advantageous if the C inRA content is as high as possible.
  • the invention further provides that the steel according to the invention has a compound of the formula [2] calculated quality G RA of the retained austenite ("retained austenite quality") of more than 6, in particular more than 8, having.
  • G RA % RA x C INRA with% RA: retained austenite content of the multiphase steel in% by volume;
  • C inRA C content of retained austenite calculated according to formula [1].
  • a cold-rolled flat product of the type according to the invention can be produced according to the invention by melting an inventive multi-phase steel in the first working step and casting it into a preliminary product.
  • This precursor may be a slab or thin slab.
  • the precursor is then, if necessary, reheated to a temperature of 1100-1300 ° C, from which the precursor is then hot rolled into a hot strip.
  • the final temperature of the hot rolling is according to the invention 820-950 ° C.
  • the resulting hot strip is wound into a coil at a reel temperature of 400-750 ° C., in particular 530-600 ° C.
  • the hot strip may be subjected to annealing after being reeled and before being cold rolled. This can be advantageously carried out as a bell annealing or completed in a continuous flow annealing.
  • the at the cold rolling preparatory annealing set annealing temperatures are typically 400 - 700 ° C.
  • the hot strip at cold rolling degrees of 30 - 80%, especially 50 - 70%, cold rolled to a cold rolled product, with cold rolling degrees of 30 - 75%, especially 50 - 65% lead particularly safe to the desired result.
  • the resulting cold-rolled product is then subjected to a heat treatment in which it undergoes a continuous annealing at a 750 - 900 ° C, in particular 800 - 830 ° C, amounting annealing temperature, then at 350 - 500 ° C, especially 370 - 460 ° C. to be subjected to an overaging treatment.
  • the annealing time over which the cold flat product is annealed in the course of continuous annealing at the annealing temperature is typically 10 - 300 s, while the duration of the over-aging treatment after annealing can be up to 800 s, with the minimum annealing time generally being 10 s becomes.
  • the annealed cold rolled product may be quenched between annealing and overaging to obtain a return to ferrite and to suppress the formation of perlite.
  • the respective set cooling rate can be at least 5 ° C / s.
  • a holding of the cold-flat product at the intermediate temperature takes place over a duration which is sufficient for the formation of the desired microstructure, on the down the cold flat product is then cooled further.
  • the annealing of the cold flat product can be carried out in the course of a fire coating, in which the cold flat product is provided with a metallic protective coating.
  • the cold strip produced according to the invention with a protective layer after the heat treatment by electrolytic coating or another deposition method.
  • the cold strip obtained can also be subjected to re-rolling at degrees of deformation of up to 10% in order to improve its dimensional stability, surface finish and mechanical properties.
  • melts S1 to S13 given in Table 1 were melted and processed into cold-rolled products K1-K41.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Sheet Steel (AREA)

Description

Die Erfindung betrifft einen Mehrphasenstahl, ein aus einem solchen Mehrphasenstahl durch Kaltwalzen erzeugtes Kaltwalzflachprodukt sowie ein Verfahren zu dessen Herstellung. Bei den erfindungsgemäßen "Flachprodukten" kann es sich um Bleche, Bänder, daraus gewonnene Zuschnitte oder vergleichbare Produkte handeln. Wenn hier von "Kaltflachprodukten" die Rede ist, dann sind damit durch Kaltwalzen erzeugte Flachprodukte gemeint.The invention relates to a multiphase steel, a Kaltwalzflachprodukt produced by such a multi-phase steel by cold rolling and a process for its preparation. The "flat products" according to the invention may be sheets, strips, blanks obtained therefrom or comparable products. If this is referred to as "cold flat products", it means flat products produced by cold rolling.

Insbesondere im Bereich des Fahrzeugkarosseriebaus besteht die Forderung nach Werkstoffen, die einerseits hohe Festigkeiten besitzen, andererseits aber auch so gut verformbar sind, dass aus ihnen mit einfachen Mitteln komplex gestaltete Bauteile geformt werden können.Particularly in the field of vehicle body construction, there is a demand for materials which, on the one hand, have high strengths but, on the other hand, are also so easily deformable that complex components can be formed from them by simple means.

Ein Mehrphasenstahl, der ein in dieser Hinsicht ausgewogenes Eigenschaftsprofil besitzen soll, ist aus der EP 1 367 143 A1 bekannt. Neben einer vergleichbar hohen Festigkeit und guten Verformbarkeit soll der bekannte Stahl auch eine besonders gute Schweißbarkeit besitzen.A multiphase steel, which should have a balanced property profile in this respect, is from the EP 1 367 143 A1 known. In addition to a comparable high strength and good ductility of the known steel should also have a particularly good weldability.

Der bekannte Stahl enthält dazu 0,03 - 0,25 Gew.-% C, durch dessen Anwesenheit in Kombination mit den anderen Legierungselementen Zugfestigkeiten von mindestens 700 MPa erreicht werden sollen. Zusätzlich unterstützt werden soll die Festigkeit des bekannten Stahls durch Mn in Gehalten von 1,4 - 3,5 Gew.-%. Al wird bei der Erschmelzung des bekannten Stahls als Oxidationsmittel eingesetzt und kann in dem Stahl in Gehalten von bis zu 0,1 Gew.-% vorhanden sein. Der bekannte Stahl kann auch bis zu 0,7 Gew.-% Si aufweisen, durch dessen Anwesenheit sich die ferritisch-martensitische Struktur des Stahls stabilisieren lässt. Cr wird dem bekannten Stahl in Gehalten von 0,05 - 1 Gew.-% zugegeben, um den Einfluss der durch den Schweißvorgang im Bereich der Schweißnaht eingetragenen Wärme zu vermindern. Für denselben Zweck sind in dem bekannten Stahl 0,005 - 0,1 Gew.-% Nb vorhanden. Nb soll dabei zusätzlich einen positiven Einfluss auf die Verformbarkeit des Stahls besitzen, da seine Anwesenheit eine Feinung des Ferritkorns mit sich bringt. Für denselben Zweck können dem bekannten Stahl 0,05 - 1 Gew.-% Mo, 0,02 - 0,5 Gew.-% V, 0,005 - 0,05 Gew.-% Ti und 0,0002 - 0,002 Gew.-% B zugegeben werden. Mo und V tragen dabei zur Härtbarkeit des bekannten Stahls bei, während Ti und B sich zusätzlich positiv auf die Festigkeit des Stahls auswirken sollen.The known steel contains to 0.03 - 0.25 wt .-% C, by its presence in combination with the other alloying elements tensile strengths of at least 700 MPa to be achieved. In addition, the strength of the known steel is to be supported by Mn in contents of 1.4-3.5% by weight. Al is used in the melting of the known steel as the oxidizing agent and may be present in the steel in amounts of up to 0.1% by weight. The known steel may also have up to 0.7% by weight of Si, the presence of which stabilizes the ferritic-martensitic structure of the steel. Cr is added to the known steel in amounts of 0.05-1% by weight in order to reduce the influence of the heat introduced by the welding process in the region of the weld. For the same purpose 0.005 - 0.1 wt .-% Nb are present in the known steel. Nb should additionally have a positive influence on the deformability of the steel, since its presence brings about a thinning of the ferrite grain. For the same purpose, 0.05 to 1% by weight of Mo, 0.02 to 0.5% by weight of V, 0.005 to 0.05% by weight of Ti and 0.0002 to 0.002% by weight of the known steel can be used. % B are added. Mo and V contribute to the hardenability of the known steel, while Ti and B should additionally have a positive effect on the strength of the steel.

Ein anderes, ebenfalls aus einem hochfesten Mehrphasenstahl bestehendes, gut verformbares Stahlblech ist aus der EP 1 589 126 B1 bekannt. Dieses bekannte Stahlblech enthält 0,10 - 0,28 Gew.-% C, 1,0 - 2,0 Gew.-% Si, 1,0 - 3,0 Gew.-% Mn, 0,03 - 0,10 Gew.-% Nb, bis zu 0,5 Gew.-% Al, bis zu 0,15 Gew.-% P, bis zu 0,02 Gew.-% S. Optional können in dem Stahlblech bis zu 1,0 Gew.-% Mo, bis zu 0,5 Gew.-% Ni, bis zu 0,5 Gew.-% Cu, bis 0,003 Gew.-% Ca bis zu 0,003 Gew.-% Seltenerdmetalle, bis zu 0,1 Gew.-% Ti oder bis zu 0,1 Gew.-% V vorhanden sein. Das Gefüge des bekannten Stahlblechs weist bezogen auf seine Gesamtstruktur einen Restaustenit-Gehalt von 5 - 20 % sowie mindestens 50 % bainitischen Ferrit auf.Another, also made of a high strength multiphase steel, well malleable steel sheet is from the EP 1 589 126 B1 known. This known steel sheet contains 0.10-0.28 wt% C, 1.0-2.0 wt% Si, 1.0-3.0 wt% Mn, 0.03-0.10 Wt% Nb, up to 0.5 wt% Al, up to 0.15 wt% P, up to 0.02 wt% S. Optionally, in the steel sheet, up to 1.0 wt% Mo, up to 0.5 wt% Ni, up to 0.5 wt% Cu, to 0.003 wt% Ca, up to 0.003 Wt .-% rare earth metals, up to 0.1 wt .-% Ti or up to 0.1 wt .-% V be present. The structure of the known steel sheet, based on its overall structure, has a retained austenite content of 5 to 20% and at least 50% bainitic ferrite.

Gleichzeitig soll der Anteil an polygonalem Ferrit an dem Gefüge des bekannten Stahlblechs höchstens 30 % betragen. Durch die Beschränkung des Anteils an polygonalem Ferrit soll in dem bekannten Stahlblech Bainit die Matrix-Phase bilden und Restautenit-Anteile vorhanden sein, die zur Ausgewogenheit von Zugfestigkeit und Verformbarkeit beitragen. Auch dabei soll die Anwesenheit von Nb sicherstellen, dass der Restaustenit-Anteil des Gefüges feinkörnig ausgebildet ist.At the same time, the proportion of polygonal ferrite in the structure of the known steel sheet should be at most 30%. By limiting the proportion of polygonal ferrite in the known steel sheet bainite to form the matrix phase and Restautenit shares be present, which contribute to the balance of tensile strength and ductility. Here, too, the presence of Nb should ensure that the retained austenite content of the microstructure is fine-grained.

Um diesen Effekt zu gewährleisten, wird im Zuge der Erzeugung des aus der EP 1 589 126 B1 bekannten Stahlblechs eine besonders hohe Anfangstemperatur des Warmwalzens von 1250 - 1350 °C gewählt. In diesem Temperaturbereich geht Nb vollständig in feste Lösung, so dass sich während des Warmwalzens des Stahls eine große Zahl von feinen Nb-Karbiden bildet, die im polygonalen Ferrit oder im Bainit vorliegen. Weiter heißt es in der EP 1 589 126 B1 , dass die hohe Anfangstemperatur des Warmwalzens zwar die Voraussetzung für die Feinheit des Restaustenits ist, jedoch nicht alleine den gewünschten Effekt hat. Vielmehr soll dazu auch eine abschließende Glühung bei Temperaturen oberhalb der Ac3-Temperatur, ein darauf folgendes kontrolliertes Abkühlen mit einer Abkühlrate von mindestens 10 °C/s bis zu einer im Bereich von 300 - 450 °C liegenden Temperatur, bei der die Bainit-Umwandlung abläuft, und schließlich ein Halten bei dieser Temperatur über eine ausreichend lange Zeit erforderlich sein.To ensure this effect is in the course of the production of the EP 1 589 126 B1 known steel sheet a particularly high initial temperature of hot rolling 1250-1350 ° C chosen. In this temperature range, Nb is completely solidified, so that during the hot rolling of the steel, a large number of fine Nb carbides are formed in the polygonal ferrite or bainite. It is said in the EP 1 589 126 B1 in that although the high initial temperature of hot rolling is the prerequisite for the fineness of the retained austenite, it does not alone have the desired effect. Rather, this is also a final annealing at temperatures above the Ac 3 temperature, followed by controlled cooling with a Cooling rate of at least 10 ° C / s up to a lying in the range of 300 - 450 ° C temperature at which the bainite transformation is completed, and finally a holding at this temperature for a sufficiently long time may be required.

Aus der EP 1 865 085 A1 ist ein hochfestes kaltgewalztes Stahlflachprodukt bekannt, bei dem eine optimierte Haftung einer metallischen Beschichtung, eine gute Verarbeitbarkeit und eine hohe Widerstandsfähigkeit gegen Wasserstoffversprödung gewährleistet sein soll. Das Stahlflachprodukt weist dazu neben Eisen und unvermeidbaren Verunreinigungen (in Masse-%) 0,06 - 0,6 % C, 1 - 6 % Mn, 0,1 - 2 % Si und 0,01 - 3 % Al auf, wobei für die Gehalte an Si und Mn die Bedingung Si/Mn ≤ 0,40 erfüllen sollen. Optional kann das Stahlflachprodukt 0,005 - 0,1 % Nb, bis zu 0,02 % S, 0,0005 - 0,1 % P, bis zu 0,01 % N, 0,005 - 0,1 % Ti, 0,0003 - 0,01 % B und 0,005 - 0,1 % V enthalten. Das Gefüge des Stahlflachprodukts soll dabei gemäß einer Variante mindestens 75 % bainitisches Ferrit und polygonales Ferrit und mindestens 3 % Restaustenit aufweisen, wobei der Anteil des polygonalen Ferrits 1 - 50 % und der Anteil des bainitischen Ferrits mindestens 40 % betragen soll. Alternativ kann das Gefüge auch mindestens 75 % angelassenes Martensit und Ferrit und mindestens 3 % Restaustenit enthalten, wobei in diesem Fall der Anteil des Ferrits 4 - 40 % und der Anteil des Martensits mindestens 50 % betragen soll. Bei seiner Herstellung durchläuft das Stahlflachprodukt ein Warmwalzen mit einer anschließenden Oberflächen- und Wärmebehandlung, bei denen speziell abgestimmte Temperaturvorgaben beachtet werden müssen. Auf diese Weise soll nicht nur die angestrebte Oberflächenbeschaffenheit, sondern auch die Bildung von Rissen bei der Umformung vermieden werden.From the EP 1 865 085 A1 is a high-strength cold-rolled steel flat product is known in which an optimized adhesion of a metallic coating, good workability and a high resistance to hydrogen embrittlement should be ensured. The flat steel product has in addition to iron and unavoidable impurities (in% by mass) 0.06 - 0.6% C, 1 - 6% Mn, 0.1 - 2% Si and 0.01 - 3% Al, wherein for the contents of Si and Mn should satisfy the condition Si / Mn ≤ 0.40. Optionally, the flat steel product may be 0.005 - 0.1% Nb, up to 0.02% S, 0.0005 - 0.1% P, up to 0.01% N, 0.005 - 0.1% Ti, 0.0003 - 0.01% B and 0.005 - 0.1% V contained. According to a variant, the structure of the flat steel product should have at least 75% bainitic ferrite and polygonal ferrite and at least 3% retained austenite, the proportion of the polygonal ferrite being 1-50% and the proportion of bainitic ferrite being at least 40%. Alternatively, the microstructure may also contain at least 75% tempered martensite and ferrite and at least 3% retained austenite, in which case the proportion of ferrite should be 4-40% and the proportion of martensite at least 50%. In its manufacture, the flat steel product undergoes hot rolling followed by surface and heat treatment, with specially adapted temperature specifications Need to become. In this way, not only the desired surface texture, but also the formation of cracks during forming should be avoided.

Aus der EP 1 431 406 A1 ist des Weiteren ein Stahl bekannt, der neben Eisen und unvermeidbaren Verunreinigungen 0,13 - 0,26 % C, 1,0 - 2,2 % Mn, 0,8 - 1,5 % Al, 0,2 - 0,6 % Si, 0,04 - 0,1 % P, max. 0,012 S, max. 0,02 % N, jeweils max. 0,1 % Ti, Nb oder V und max. 0,001 % B enthalten kann. Der so beschaffene Stahl wird zu Brammen vergossen, bei einer oberhalb der Ar3-Temperaur liegenden Warmwalzendtemperatur warmgewalzt, bei einer 500 - 680 °C betragenden Haspeltemperatur gehaspelt, anschließend gebeizt und dann bei einem Kaltwalzgrad von mindestens 40 % zu einem Kaltband kaltgewalzt. Die so erhaltenen Kaltbänder sollen eine Zugefestigkeit von mindestens 590 MPa, eine Streckgrenze von 320 - 480 MPa und eine Dehnung A80 von mehr als 26 % aufweisen.From the EP 1 431 406 A1 Further, there is known a steel containing, in addition to iron and unavoidable impurities, 0.13-0.26% C, 1.0-2.2% Mn, 0.8-1.5% Al, 0.2-0.6 % Si, 0.04 - 0.1% P, max. 0,012 S, max. 0.02% N, max. 0.1% Ti, Nb or V and max. 0.001% B may contain. The thus constituted steel is cast into slabs, hot rolled at a temperature above the Ar 3 -Temperaur hot-rolling, at a 500-680 ° C amount coiling temperature coiled, then pickled and then cold rolled at a cold-rolling degree of at least 40% to form a cold strip. The cold-rolled strips obtained in this way should have a tensile strength of at least 590 MPa, a yield strength of 320-480 MPa and an elongation A80 of more than 26%.

In Bleck et al. "Control of microstructure in TRIP steels by niobium", Mat. Science Forum, ISSN: 0255-5476, CH, Bd 426 - 432, Nr. 1, (2003-01-01 ), Seiten 43 - 48, ist schließlich auf Grundlage einer Stahllegierung, die neben Eisen und unvermeidbaren Verunreinigungen (in Masse-%) 0,2 % C, 1,4 % Mn, 0,5 % Si, 0,75 % Al und 0,04 % P sowie optional 0,03 % Nb enthält, der Einfluss von Nb auf die Ausprägung des Gefüges in Abhängigkeit von verschiedenen Wärmebehandlungen erläutert.In Bleck et al. "Control of microstructure in TRIP steels by niobium", Mat. Science Forum, ISSN: 0255-5476, CH, Vol. 426-432, No. 1, (2003-01-01 ), Pages 43-48, is finally based on a steel alloy, in addition to iron and unavoidable impurities (in% by mass) 0.2% C, 1.4% Mn, 0.5% Si, 0.75% Al and 0.04% P and optionally 0.03% Nb, the influence of Nb on the shape of the structure depending on different heat treatments explained.

Vor dem Hintergrund des voranstehend beschriebenen Standes der Technik bestand die Aufgabe der Erfindung darin, einen Mehrphasenstahl mit einer weiter erhöhten Festigkeit zu schaffen, der gleichzeitig eine hohe Bruchdehnung besitzt. Ebenso sollten ein Flachprodukt mit einer weiter optimierten Kombination aus hoher Festigkeit und gute Verformbarkeit sowie ein Verfahren zur Herstellung eines solchen Flachproduktes angegeben werden.Against the background of the prior art described above, the object of the invention was to further increase a multiphase steel To provide strength, which also has a high elongation at break. Likewise, a flat product with a further optimized combination of high strength and good ductility and a method for producing such a flat product should be specified.

In Bezug auf den Stahl ist die voranstehend angegebene Aufgabe erfindungsgemäß durch einen gemäß Anspruch 1 beschaffenen Stahl gelöst worden.With regard to the steel, the above-mentioned object has been achieved according to the invention by a procured according to claim 1 steel.

In Bezug auf das Flachprodukt besteht die Lösung der oben genannten Aufgabe in einem gemäß Anspruch 11 ausgebildeten Kaltflachprodukt.With regard to the flat product, the solution of the above-mentioned object consists of a cold flat product designed according to claim 11.

Im Hinblick auf das Verfahren ist die oben angegebene Aufgabe schließlich erfindungsgemäß dadurch gelöst worden, dass die in Anspruch 12 angegebenen Arbeitsschritte durchlaufen werden.With regard to the method, the abovementioned object has finally been achieved according to the invention in that the working steps specified in claim 12 are run through.

Vorteilhafte Ausgestaltungen der Erfindung sind in den abhängigen Ansprüchen angegeben und werden nachfolgend gemeinsam mit dem allgemeinen Erfindungsgedanken im Einzelnen erläutert.Advantageous embodiments of the invention are specified in the dependent claims and will be explained in detail together with the general inventive concept.

Ein erfindungsgemäßer Mehrphasenstahl enthält (in Gew.-%) C: 0,14 - 0,25 %, Mn: 1, 7 - 2, 5 %, Si: 0,2 - 0, 7 %, Al: 0,5 - 1, 5 %, Cr: < 0,1 %, Mo: < 0,05 %, Nb: 0,02 - 0,06 %, S: bis zu 0,01 %, insbesondere bis zu 0,005 %, P: bis zu 0,02 %, N: bis zu 0,01 %, sowie optional mindestens ein Element aus der Gruppe "Ti, B, V", und als Rest Eisen und unvermeidbare Verunreinigungen, wobei für die Gehalte der optional vorgesehenen Elemente vorgesehen ist, dass Ti: ≤ 0,1 %, B: ≤ 0,002 %, V: ≤ 0,15 % und wobei im Gefüge des Stahls mindestens 10 Vol.-% Ferrit sowie mindestens 6 Vol.-% Restaustenit vorhanden sind.A multiphase steel according to the invention contains (in% by weight) C: 0.14-0.25%, Mn: 1, 7-2.5%, Si: 0.2-0.7%, Al: 0.5- 1, 5%, Cr: <0.1%, Mo: <0.05%, Nb: 0.02-0.06%, S: up to 0.01%, in particular up to 0.005%, P: to to 0.02%, N: up to 0.01%, and optionally at least one element from the group "Ti, B, V", and the balance iron and unavoidable impurities, wherein for the contents of the optionally provided elements are provided such that Ti: ≦ 0.1%, B: ≦ 0.002%, V: ≦ 0.15% and wherein in the structure of the steel at least 10% by volume of ferrite and at least 6% by volume. % Retained austenite are present.

Ein erfindungsgemäß zusammengesetzter und beschaffener Stahl erreicht eine Zugfestigkeit Rm von mindestens 950 MPa, eine Streckgrenze ReL von mindestens 500 MPa und eine Bruchdehnung A80 in Querrichtung von mindestens 15 %.A steel assembled and obtained according to the invention achieves a tensile strength R m of at least 950 MPa, a yield strength R eL of at least 500 MPa and an elongation at break A 80 in the transverse direction of at least 15%.

Kohlenstoff erhöht die Menge und die Stabilität des Restaustenits. In erfindungsgemäßem Stahl ist daher mindestens 0,14 Gew.-% Kohlenstoff vorhanden, um den Austenit bis Raumtemperatur zu stabilisieren und eine vollständige Umwandlung des bei einer Glühbehandlung gebildeten Austenits in Martensit, Ferrit oder Bainit bzw. bainitischen Ferrit zu verhindern. Über 0,25 Gew.-% liegende Kohlenstoffgehalte wirken sich jedoch auf die Schweißeignung negativ aus.Carbon increases the amount and stability of retained austenite. Therefore, in the steel of the present invention, at least 0.14 wt% of carbon is present to stabilize the austenite to room temperature and to prevent complete conversion of the austenite formed in an annealing treatment into martensite, ferrite or bainite, and bainitic ferrite, respectively. However, over 0.25 wt .-% lying carbon contents have a negative effect on the weldability.

Mn trägt wie C zur Festigkeit und zur Erhöhung der Menge und der Stabilität des Restaustenits bei. Zu hohe Mn-Gehalte verstärken jedoch die Gefahr der Seigerungsbildung. Sie wirken sich zudem negativ auf die Bruchdehnung aus, da die Ferrit- und Bainit-Umwandlungen stark verzögert werden und als Folge vergleichbar hohe Mengen an Martensit im Gefüge verbleiben. Der Mn-Gehalt eines erfindungsgemäßen Stahls ist auf 1,7 - 2,5 Gew.-% festgesetzt.Like C, Mn contributes to the strength and increase the amount and stability of the retained austenite. However, excessive Mn levels increase the risk of segregation. They also have a negative effect on the elongation at break, since the ferrite and bainite conversions are greatly delayed and, as a result, comparatively high amounts of martensite remain in the microstructure. The Mn content of a steel according to the invention is set at 1.7-2.5% by weight.

In einem erfindungsgemäßen Stahl sind Al in Gehalten von 0,5 - 1,5 Gew.-% und Si in Gehalten von 0,2 - 0,7 Gew.-% vorhanden, um bei der im Zuge der erfindungsgemäßen Verarbeitung des Stahls durchgeführten Überalterungsbehandlung die Karbidbildung in der Bainitstufe zu vermeiden. Die Bainitumwandlung läuft in Folge der Anwesenheit von Al und Si nicht vollständig ab, so dass nur bainitischer Ferrit gebildet wird und die Karbidbildung nicht zu Stande kommt. Auf diese Weise wird die erfindungsgemäß angestrebte Stabilität von an Kohlenstoff angereichertem Restaustenit erzielt. Besonders sicher lässt sich dieser Effekt dadurch gewährleisten, dass der Si-Gehalt auf bis zu 0,6 Gew.-% oder der Al-Gehalt auf 0,7 - 1,4 Gew.-% beschränkt werden, wobei Si-Gehalte von mehr als 0,2 Gew.-% und weniger als 0,6 Gew.-% eingestellt werden und die Al-Gehalte zwischen 0,7 Gew.-% und 1,4 Gew.-% liegen. Bei kombinierter Anwesenheit von Si und Al ergeben sich optimale Eigenschaften des erfindungsgemäßen Mehrphasenstahls, wenn die Summe seiner Al- und Si-Gehalte 1,2 - 2,0 Gew.-% beträgt.In a steel according to the invention, Al are present in amounts of 0.5-1.5% by weight and Si in contents of 0.2-0.7% by weight. present in order to avoid carbide formation in the bainite step in the over-aging treatment carried out in the course of the inventive processing of the steel. The bainite transformation does not proceed completely due to the presence of Al and Si, so that only bainitic ferrite is formed and carbide formation does not occur. In this way, the present invention desired stability of carbon-enriched retained austenite is achieved. This effect can be ensured particularly reliably by limiting the Si content to 0.6% by weight or the Al content to 0.7-1.4% by weight, with Si contents of more than are set as 0.2 wt .-% and less than 0.6 wt .-% and the Al contents between 0.7 wt .-% and 1.4 wt .-% are. In the combined presence of Si and Al, optimum properties of the multiphase steel according to the invention result when the sum of its Al and Si contents is 1.2-2.0% by weight.

Cr und Mo sind in einem erfindungsgemäßen Stahl unerwünscht und sollen daher nur in unwirksamen Mengen vorhanden sein, da sie die bainitische Umwandlung verzögern und die Stabilisierung des Restaustenits behindern. Daher ist erfindungsgemäß der Cr-Gehalt auf weniger als 0,1 Gew.-% und der Mo-Gehalt eines erfindungsgemäßen Stahls auf weniger als 0,05 Gew.-%, insbesondere weniger als 0,01 Gew.-%, beschränkt.Cr and Mo are undesirable in a steel according to the invention and should therefore be present only in ineffective amounts, as they delay the bainitic transformation and hinder the stabilization of the retained austenite. Therefore, according to the invention, the Cr content is limited to less than 0.1% by weight and the Mo content of a steel according to the invention to less than 0.05% by weight, in particular less than 0.01% by weight.

Ein erfindungsgemäßer Stahl enthält Nb in Gehalten von 0,02 - 0,06 Gew.-% sowie optional eines oder mehrere der Elemente "Ti, V, B", um die Festigkeit des erfindungsgemäßen Stahls zu steigern. Nb, Ti, V und B bilden mit dem im erfindungsgemäßen Stahl vorhandenen C und N sehr feine Ausscheidungen. Diese Ausscheidungen wirken festigkeits- und streckgrenzensteigernd durch Teilchenhärtung und Kornfeinung. Die Kornfeinung ist auch für die umformtechnischen Eigenschaften des Stahls von großem Vorteil.A steel according to the invention contains Nb in amounts of 0.02-0.06% by weight and optionally one or more of the elements "Ti, V, B" in order to increase the strength of the steel steel according to the invention. Nb, Ti, V and B form very fine precipitates with the C and N present in the steel according to the invention. These precipitates increase strength and yield strength by particle hardening and grain refining. The grain refining is also of great advantage for the forming properties of the steel.

Ti bindet N noch bei der Erstarrung bzw. bei sehr hohen Temperaturen ab, so dass mögliche negative Wirkungen dieses Elements auf die Eigenschaften des erfindungsgemäßen Stahls auf ein Minimum reduziert sind. Um diese Effekte zu nutzen, kann einem erfindungsgemäßen Stahl zusätzlich zum stets vorhandenen Nb bis zu 0,1 Gew.-% Ti und bis zu 0,15 Gew.-% V zugegeben werden.Ti still binds N during solidification or at very high temperatures, so that possible negative effects of this element on the properties of the steel according to the invention are reduced to a minimum. In order to utilize these effects, up to 0.1% by weight of Ti and up to 0.15% by weight of V can be added to a steel according to the invention in addition to the ever present Nb.

Eine Überschreitung der erfindungsgemäß vorgegebenen Obergrenzen der Gehalte an Mikrolegierungselementen würde zur Verzögerung der Rekristallisation während des Glühens führen, so dass diese bei der realen Produktion entweder nicht realisiert werden kann oder eine zusätzliche Ofenleistung erfordern würde.Exceeding the inventively given upper limits of the contents of micro-alloying elements would lead to the delay of the recrystallization during annealing, so that they either can not be realized in real production or would require an additional furnace performance.

Der positive Einfluss der Anwesenheit von Ti in Bezug auf die Abbindung des N-Gehalts kann dann besonders zielgerichtet genutzt werden, wenn der Ti-Gehalt "%Ti" eines erfindungsgemäßen Mehrphasenstahls folgende Bedingung [3] erfüllt: % Ti ≥ 3 , 4 x % N ,

Figure imgb0001
wobei mit "%N" der jeweilige N-Gehalt des Mehrphasenstahls bezeichnet ist und diese Bedingung insbesondere dann einzuhalten ist, wenn der Ti-Gehalt 0,01 - 0,03 Gew.-% beträgt.The positive influence of the presence of Ti with respect to the setting of the N content can be used particularly purposefully if the Ti content "% Ti" of a multiphase steel according to the invention fulfills the following condition [3]: % Ti ≥ 3 . 4 x % N .
Figure imgb0001
 where "% N" denotes the respective N content of the multiphase steel and this condition is to be observed, in particular, when the Ti content is 0.01-0.03 wt%.

Besonders sicher tritt die positive Wirkung von Ti in einem erfindungsgemäßen Stahl dann ein, wenn sein Ti-Gehalt mindestens 0,01 Gew.-% beträgt.The positive effect of Ti in a steel according to the invention occurs particularly reliably when its Ti content is at least 0.01% by weight.

Durch die Zugabe von bis zu 0,002 Gew.-% Bor kann die Ferritbildung bei der Abkühlung verzögert werden, so dass eine größere Austenitmenge in der Bainitstufe vorliegt. Dadurch können die Menge und die Stabilität des Restaustenits erhöht werden. Darüber hinaus wird statt normalem Ferrit bainitischer Ferrit gebildet, der zur Erhöhung der Streckgrenze beiträgt.The addition of up to 0.002 wt .-% boron, the ferrite formation can be delayed upon cooling, so that a larger amount of austenite is present in the bainite. As a result, the amount and the stability of the retained austenite can be increased. In addition, bainitic ferrite is formed instead of normal ferrite, which contributes to increasing the yield strength.

Praxisgerechte, im Hinblick auf die Kosten und das Eigenschaftsprofil des erfindungsgemäßen Stahls besonders vorteilhafte Varianten des erfindungsgemäßen Stahls ergeben sich, wenn der Ti-Gehalt auf 0,02 Gew.-% beschränkt ist sowie B in Gehalten von 0,0005 - 0,002 Gew.-% oder V in Gehalten von 0,06 - 0,15 Gew.-% vorhanden sind.Practical variants of the steel according to the invention that are particularly advantageous with regard to the costs and the property profile of the steel according to the invention result if the Ti content is limited to 0.02% by weight and B in amounts of 0.0005-0.002% by weight. % or V are present at levels of 0.06 - 0.15% by weight.

Im Gefüge eines erfindungsgemäßen Stahls sind mindestens 10 Vol.-% Ferrit, insbesondere mindestens 12 Vol.-% Ferrit, sowie mindestens 6 Vol.-% Restaustenit vorhanden, um einerseits die angestrebte hohe Festigkeit und andererseits die gute Verformbarkeit zu sichern. Dazu können abhängig von der Menge der übrigen Gefügebestandteile bis zu 90 Vol.-% des Gefüges aus Ferrit und bis maximal 20 Vol.-% aus Restaustenit bestehen. Gehalte von mindestens 5 Vol.-% Martensit im Gefüge des erfindungsgemäßen Stahls tragen zu dessen Festigkeit bei, wobei der Martensitgehalt auf max. 40 Vol.-% beschränkt sein sollte, um eine ausreichende Dehnbarkeit des erfindungsgemäßen Stahls sicherzustellen. Dabei können optional 5 - 40 Vol.-% Bainit im Gefüge eines erfindungsgemäßen Stahls vorhanden sein.At least 10% by volume of ferrite, in particular at least 12% by volume of ferrite, and at least 6% by volume of retained austenite are present in the structure of a steel according to the invention, in order to ensure the desired high strength on the one hand and good ductility on the other hand. Depending on the amount of the remaining structural constituents, up to 90% by volume of the microstructure can be used for this purpose Ferrite and up to 20 vol .-% consist of retained austenite. Contents of at least 5 vol.% Martensite in the structure of the steel according to the invention contribute to its strength, wherein the martensite content to max. 40 vol .-% should be limited to ensure sufficient extensibility of the steel according to the invention. In this case, optionally 5 to 40% by volume of bainite can be present in the microstructure of a steel according to the invention.

Erfindungsgemäß ist der Restaustenit eines erfindungsgemäßen Stahls so mit Kohlenstoff angereichert, dass sein gemäß der im Artikel von A. Zarei Hanzaki et al. in ISIJ Int. Vol. 35, No 3, 1995, pp. 324 - 331 veröffentlichten Formel [1] berechneter CinRA-Gehalt mehr als 0,6 Gew.-% beträgt. C inRA = a RA - a γ / 0 , 0044

Figure imgb0002

mit aγ: 0,3578 nm (Gitterkonstante des Austenits);
aRA: jeweiliger Gitterparameter des Restaustenits nach der Endabkühlung in nm am fertigen Kaltband gemessen.According to the invention, the retained austenite of a steel according to the invention is enriched with carbon in such a way that its content is as described in the article of A. Zarei Hanzaki et al. in ISIJ Int. Vol. 35, No 3, 1995, pp. 324 - 331 published formula [1] calculated C inRA content is more than 0.6 wt .-%. C INRA = a RA - a γ / 0 . 0044
Figure imgb0002
with a γ : 0.3578 nm (lattice constant of austenite);
a RA : respective lattice parameter of the retained austenite after final cooling in nm measured on the finished cold strip.

Die Menge des im Restaustenit vorhandenen Kohlenstoffs beeinflusst wesentlich die TRIP-Eigenschaften und die Dehnbarkeit eines erfindungsgemäßen Stahls. Dementsprechend ist es vorteilhaft, wenn der CinRA-Gehalt so hoch wie möglich ist.The amount of carbon present in the retained austenite substantially affects the TRIP properties and ductility of a steel according to the invention. Accordingly, it is advantageous if the C inRA content is as high as possible.

In Bezug auf die angestrebt hohe Stabilität des Restaustenits sieht die Erfindung darüber hinaus vor, dass der erfindungsgemäße Stahl eine nach der Formel [2] berechnete Güte GRA des Restaustenits ("Restaustenitgüte") von mehr als 6, insbesondere mehr als 8, aufweist. G RA = % RA x C inRA

Figure imgb0003

mit %RA: Restaustenit-Gehalt.des Mehrphasenstahls in Vol.-%;
CinRA:C-Gehalt des Restaustenits berechnet gemäß Formel [1].With regard to the desired high stability of the retained austenite, the invention further provides that the steel according to the invention has a compound of the formula [2] calculated quality G RA of the retained austenite ("retained austenite quality") of more than 6, in particular more than 8, having. G RA = % RA x C INRA
Figure imgb0003
with% RA: retained austenite content of the multiphase steel in% by volume;
C inRA : C content of retained austenite calculated according to formula [1].

Ein kaltgewalztes Flachprodukt der erfindungsgemäßen Art lässt sich in erfindungsgemäßer Weise dadurch erzeugen, dass im ersten Arbeitsschritt ein erfindungsgemäßer Mehrphasenstahl erschmolzen und zu einem Vorprodukt vergossen wird. Bei diesem Vorprodukt kann es sich um eine Bramme oder Dünnbramme handeln.A cold-rolled flat product of the type according to the invention can be produced according to the invention by melting an inventive multi-phase steel in the first working step and casting it into a preliminary product. This precursor may be a slab or thin slab.

Das Vorprodukt wird dann erforderlichenfalls auf eine 1100 - 1300 °C betragende Temperatur wiedererwärmt, von der ausgehend das Vorprodukt anschließend zu einem Warmband warmgewalzt wird. Die Endtemperatur des Warmwalzens beträgt erfindungsgemäß 820 - 950 °C. Das erhaltene Warmband wird bei einer 400 - 750 °C, insbesondere 530 - 600 °C, betragenden Haspeltemperatur zu einem Coil gewickelt.The precursor is then, if necessary, reheated to a temperature of 1100-1300 ° C, from which the precursor is then hot rolled into a hot strip. The final temperature of the hot rolling is according to the invention 820-950 ° C. The resulting hot strip is wound into a coil at a reel temperature of 400-750 ° C., in particular 530-600 ° C.

Um die Kaltwalzbarkeit des Warmbands zu verbessern, kann das Warmband nach dem Haspeln und vor dem Kaltwalzen einer Glühung unterzogen werden. Diese kann vorteilhafterweise als Haubenglühung oder im kontinuierlichen Durchlauf absolvierte Glühung durchgeführt werden. Die bei der das Kaltwalzen vorbereitenden Glühung eingestellten Glühtemperaturen betragen typischerweise 400 - 700 °C.In order to improve the cold rolling capability of the hot strip, the hot strip may be subjected to annealing after being reeled and before being cold rolled. This can be advantageously carried out as a bell annealing or completed in a continuous flow annealing. The at the cold rolling preparatory annealing set annealing temperatures are typically 400 - 700 ° C.

Nach dem Haspeln wird das Warmband bei Kaltwalzgraden von 30 - 80 %, insbesondere 50 - 70 %, zu einem Kaltflachprodukt kaltgewalzt, wobei Kaltwalzgrade von 30 - 75 %, insbesondere 50 - 65 % besonders sicher zu dem gewünschten Ergebnis führen. Das erhaltene Kaltflachprodukt wird anschließend einer Wärmbehandlung unterzogen, bei der es zunächst ein Durchlaufglühen bei einer 750 - 900 °C, insbesondere 800 - 830 °C, betragenden Glühtemperatur durchläuft, um anschließend bei einer 350 - 500 °C, insbesondere 370 - 460 °C, betragenden Überalterungstemperatur einer Überalterungsbehandlung unterzogen zu werden. Die Glühdauer, über die das Kaltflachprodukt im Zuge des Durchlaufglühens bei der Glühtemperatur geglüht wird, beträgt typischerweise 10 - 300 s, während die Dauer der nach dem Glühen durchgeführten Überalterungsbehandlung bis zu 800 s betragen kann, wobei hier in der Regel die Mindestglühdauer 10 s betragen wird.After coiling, the hot strip at cold rolling degrees of 30 - 80%, especially 50 - 70%, cold rolled to a cold rolled product, with cold rolling degrees of 30 - 75%, especially 50 - 65% lead particularly safe to the desired result. The resulting cold-rolled product is then subjected to a heat treatment in which it undergoes a continuous annealing at a 750 - 900 ° C, in particular 800 - 830 ° C, amounting annealing temperature, then at 350 - 500 ° C, especially 370 - 460 ° C. to be subjected to an overaging treatment. The annealing time over which the cold flat product is annealed in the course of continuous annealing at the annealing temperature is typically 10 - 300 s, while the duration of the over-aging treatment after annealing can be up to 800 s, with the minimum annealing time generally being 10 s becomes.

Optional kann das geglühte Kaltflachprodukt zwischen dem Glühen und dem Überaltern beschleunigt abgekühlt werden, um eine Rückumwandlung in Ferrit zu erlangen und die Entstehung von Perlit zu unterdrücken. Ausgehend von der Glühtemperatur bis zu einer 500 °C betragenden Zwischentemperatur kann dazu die jeweils eingestellte Abkühlgeschwindigkeit mindestens 5 °C/s betragen. Anschließend erfolgt gegebenenfalls über eine für die Entstehung des gewünschten Gefüges ausreichende Dauer ein Halten des Kaltflachprodukts bei der Zwischentemperatur, auf das hin das Kaltflachprodukt dann weiter abgekühlt wird.Optionally, the annealed cold rolled product may be quenched between annealing and overaging to obtain a return to ferrite and to suppress the formation of perlite. Starting from the annealing temperature up to an intermediate temperature of 500 ° C, the respective set cooling rate can be at least 5 ° C / s. Thereafter, if necessary, a holding of the cold-flat product at the intermediate temperature takes place over a duration which is sufficient for the formation of the desired microstructure, on the down the cold flat product is then cooled further.

Das Glühen des Kaltflachprodukts kann im Zuge einer Feuerbeschichtung durchgeführt werden, bei der das Kaltflachprodukt mit einer metallischen Schutzbeschichtung versehen wird.The annealing of the cold flat product can be carried out in the course of a fire coating, in which the cold flat product is provided with a metallic protective coating.

Ebenso ist es möglich, das erfindungsgemäß erzeugte Kaltband nach der Wärmebehandlung durch elektrolytisches Beschichten oder ein anderes Abscheideverfahren mit einer Schutzschicht zu versehen.It is likewise possible to provide the cold strip produced according to the invention with a protective layer after the heat treatment by electrolytic coating or another deposition method.

Ergänzend oder alternativ kann es ebenso zweckmäßig sein, das Kaltflachprodukt mit einer organischen Schutzschicht zu belegen.Additionally or alternatively, it may also be expedient to cover the cold-rolled product with an organic protective layer.

Optional kann das erhaltene Kaltband auch noch einer Nachwalzung bei Verformungsgraden von bis zu 10 % unterzogen werden, um seine Maßhaltigkeit, Oberflächenbeschaffenheit und mechanische Eigenschaften zu verbessern.Optionally, the cold strip obtained can also be subjected to re-rolling at degrees of deformation of up to 10% in order to improve its dimensional stability, surface finish and mechanical properties.

Zum Nachweis der Eigenschaften erfindungsgemäß beschaffener und erzeugter Bleche sind die in Tabelle 1 angegebenen Schmelzen S1 bis S13 erschmolzen und zu Kaltflachprodukten K1 - K41 verarbeitet worden.To demonstrate the properties of sheets produced and produced according to the invention, the melts S1 to S13 given in Table 1 were melted and processed into cold-rolled products K1-K41.

Die Erzeugung der Kaltflachprodukte K1 - K41 umfasste die Arbeitsschritte:

  • Erschmelzen und Vergießen der Schmelzen S1 - S13 zu jeweils einer Dünnbramme;
  • Warmwalzen der Dünnbramme des Vorprodukts ausgehend von einer Anfangstemperatur WAT und endend bei einer Endtemperatur WET zu einem Warmband;
  • Haspeln des Warmbands bei einer Haspeltemperatur HT;
  • Kaltwalzen des Warmbands nach dem Haspeln bei Kaltwalzgraden KWG zum jeweiligen Kaltflachprodukt K1 - K41;
  • Durchlaufglühen des Kaltflachprodukts bei einer Glühtemperatur GT innerhalb einer Glühdauer Gt;
  • Überaltern des Kaltflachprodukts bei einer betragenden Überalterungstemperatur UA T über eine Überalterungsdauer UA t.
    In Tabelle 2 sind für Glüh- und Überalterungszyklen 1 - 15 die jeweils eingestellten Parameter "Glühtemperatur GT", "Glühzeit Gt", "Abkühlgeschwindigkeit V nach dem Glühen", "Überalterungstemperatur UA T" und "Überalterungszeit UA t" angegeben.
The production of cold flat products K1 - K41 included the following steps:
  • Melting and casting of the melts S1 - S13 into one thin slab each;
  • Hot rolling the thin slab of the precursor from an initial temperature WAT and ending at a final temperature WET to a hot strip;
  • Coiling the hot strip at a reel temperature HT;
  • Cold rolling of the hot strip after reeling with cold rolling degrees KWG to the respective cold flat product K1 - K41;
  • Continuous annealing of the cold flat product at an annealing temperature GT within an annealing time Gt;
  • Overaging of the cold-rolled product at an excess aging temperature UA T over an overaging period UA t.
    Table 2 shows the respectively set parameters "annealing temperature GT", "annealing time Gt", "cooling rate V after annealing", "aging temperature UA T" and "aging time UA t" for annealing and overaging cycles 1-15.

Die bei der Erzeugung der als Kaltbänder oder -bleche vorliegenden Kaltflachprodukte K1 - K41 im Übrigen jeweils eingestellten Parameter, der jeweils gewählte Glühzyklus sowie die Eigenschaften der erhaltenen Kaltbänder K1 - K41 sind in Tabelle 3 verzeichnet. Tabelle 1 (Gehaltsangaben in Gew.-%, Rest Eisen und unvermeidbare Verunreinigungen) Schmelze C Si Mn Al Nb V Ti P S N B Erfindungsgemäß? S1 0,210 0,41 1,82 1, 020 0,041 0,004 0,005 0,004 0,003 0,0015 0,0005 JA S2 0,250 0,42 1,79 0, 970 0,044 0,006 0,003 0,005 0,004 0,0041 0,0004 JA S3 0,230 0,42 2, 48 0, 980 0,042 0,005 0,015 0,006 0,005 0,0016 0,0004 JA S4 0,220 0,42 2,27 0, 98 0,040 0, 011 0,015 0,004 0,003 0,0016 0,0016 JA S5 0,231 0,70 1,83 1,020 0,044 0, 120 0,006 0,004 0,003 0,0015 0,0005 JA S6 0,220 0,40 1,83 1,03 0,045 0,006 0,003 0,004 0,005 0,0011 0,0006 JA S7 0,231 0,40 1,90 1,400 0,025 0, 100 0,007 0,004 0,004 0,0013 0,0004 JA S8 0,215 0,41 2,23 0,970 0, 058 0,005 0,004 0,003 0,004 0,0014 0,0005 JA S9 0,222 0,40 1,80 1,01 0,045 0,10 0,003 0,004 0,004 0,0017 0,0005 JA S10 0,220 0,65 1,95 1,250 0,029 0,006 0, 019 0,005 0,003 0,0016 0,0013 JA S11 0,215 0,41 2,24 0,91 0,041 0, 11 0,004 0,005 0,003 0,0016 0,0005 JA S12 0,220 0,35 2,50 1,230 0,027 0, 005 0,017 0,005 0,003 0,0016 0,0010 JA S13 0,226 0,41 1, 81 1,03 0,003 0,005 0,001 0,003 0,005 0,0013 0,0006 NEIN Tabelle 2 GlühZyklus Nr. GT [°C] Gt [s] V [°C/s] UA T [°C] UA t [s] 1 820 60 15 375 60 2 820 60 15 375 120 3 820 60 15 375 360 4 820 60 15 425 30 5 820 60 15 425 60 6 820 60 15 425 120 7 820 60 15 450 30 8 820 60 15 450 60 9 820 60 15 450 120 10 820 60 50 425 30 11 820 60 50 425 60 12 820 60 50 425 120 13 820 60 100 425 120 14 840 60 100 425 120 15 860 60 100 425 120 Tabelle 3 Schmelze Glüh.Nr. WAT [°C] WET [°C] HT [°C] KWG [%] ReL [MPa] Rm [MPa] A80 [%] RA [Vol-%] CinRA [Gew.-%] Güte RA aRa [nm] Erfindungsgemäß? K1 S1 1 1250 940 600 65 512 975 23,1 18,0 0,76 13,68 0,3611 ja K2 S1 2 1260 940 610 68 550 1002 23,7 17,0 0,78 13,26 0,3612 ja K3 S1 3 1250 930 620 63 561 963 24,6 16,5 0,81 13,37 0,3614 ja K4 S2 13 1300 930 700 63 614 1070 18,2 15,0 0,91 13,65 0,3618 ja K5 S2 14 1140 950 690 55 603 1050 23,1 15,5 0,93 14,42 0,3619 ja K6 S2 15 1250 870 400 56 580 1020 23,6 17,0 0,94 15,98 0,3619 ja K7 S3 10 1160 860 430 52 552 1.103 15,5 15,0 0,65 9,75 0,3607 ja K8 S3 11 1180 870 420 55 584 1070 17,1 17,5 0,74 12,95 0,3611 ja K9 S3 12 1180 920 560 54 570 1007 18,2 18,0 0,78 14,04 0,3612 ja K10 S4 10 1190 920 560 63 509 964 16,1 15,5 0,73 11,32 0,3610 ja K11 S4 11 1170 910 550 75 592 990 18,5 18,0 0,82 14,76 0,3614 ja K12 S4 12 1260 910 530 73 548 1050 21,4 19,0 0,80 15,20 0,3613 ja K13 S4 14 1240 820 450 30 517 1035 25,6 13,0 0,95 12,35 0,3620 ja K14 S5 7 1300 940 560 54 503 981 18,1 16,5 0,78 12,87 0,3612 ja K15 S5 8 1250 830 450 45 524 968 19,3 17,5 0,83 14,53 0,3615 ja K16 S5 9 1140 850 460 50 563 1003 20,8 18,0 0,85 15,30 0,3615 ja K17 S6 4 1150 900 500 50 532 1010 25,9 18,0 0,84 15,12 0,3615 ja K18 S6 5 1300 900 530 56 575 986 26,6 16,5 0,91 15,02 0,3618 ja K19 S6 6 1290 930 530 53 584 978 28,0 16,5 0,95 15,68 0,3620 ja K20 S7 4 1280 920 540 54 520 965 22,1 17,5 0,76 13,30 0,3611 ja K21 S7 5 1280 930 700 56 536 954 22,5 18,0 0,81 14,58 0,3614 ja K22 S7 6 1290 910 650 58 587 992 21,4 18,5 0,84 15,54 0,3615 ja K23 S8 13 1150 880 430 60 571 997 20,7 14,5 0,91 13,20 0,3618 ja K24 S8 14 1150 870 460 65 525 981 22,4 15,0 0,95 14,25 0,3620 ja K25 S8 15 1100 880 460 45 521 962 24,1 15,5 0,94 14,57 0,3619 ja K26 S9 4 1160 930 660 63 511 1009 18,7 17,0 0,77 13,09 0,3612 ja K27 S9 5 1230 950 650 62 526 1021 19,5 17,5 0,82 14,35 0,3614 ja K28 S9 6 1230 950 650 70 574 1019 21,2 18,5 0,86 15,91 0,3616 ja K29 S10 10 1170 940 680 75 510 1003 20,1 17,5 0,79 13,83 0,3613 ja K30 S10 11 1240 930 560 64 564 997 21,6 18,5 0,84 15,54 0,3615 ja K31 S10 12 1200 850 490 55 589 1011 22,2 18,5 0,88 16,28 0,3617 ja K32 S11 10 1190 860 470 46 545 1130 15,5 15,0 0,70 10,50 0,3609 ja K33 S11 11 1190 870 470 35 529 1062 16,7 17,0 0,82 13,94 0,3614 ja Schmelze Glüh.Nr. WAT [°C] WET [°C] HT [°C] KWG [%] ReL [MPa] Rm [MPa] A80 [%] RA [Vol-%] CinRA [Gew.-%] Güte RA aRa [nm] Erfindungsgemäß? K34 S11 12 1150 910 530 49 602 1018 18,1 18,0 0,80 14,40 0,3613 ja K35 S11 14 1160 920 520 51 608 993 23,4 13,5 0,93 12,56 0,3619 ja K36 S12 10 1140 910 520 52 542 1089 15,9 15,5 0,65 10,08 0,3607 ja K37 S12 11 1200 920 530 50 583 1054 18,1 17,0 0,63 10,71 0,3606 ja K38 S12 12 1210 930 560 49 589 1023 19,4 18,5 0,67 12,40 0,3607 ja K39 S13 7 1210 940 700 70 404 796 30,0 19,5 0,91 17,75 0,3618 nein K40 S13 8 1220 860 410 45 440 763 27,0 18,0 0,93 16,74 0,3619 nein K41 S13 9 1230 870 420 60 453 775 25,4 17,5 0,95 16,63 0,3620 nein The cold-rolled products K1-K41, which are otherwise set in the production of the cold strips or sheets, the respectively set annealing cycle and the properties of the cold strips K1-K41 obtained are listed in Table 3. Table 1 (content by weight in%, balance iron and unavoidable impurities) melt C Si Mn al Nb V Ti P S N B According to the invention? S1 0.210 0.41 1.82 1, 020 0,041 0,004 0.005 0,004 0,003 0.0015 0.0005 YES S2 0,250 0.42 1.79 0, 970 0,044 0,006 0,003 0.005 0,004 0.0041 0.0004 YES S3 0.230 0.42 2, 48 0, 980 0,042 0.005 0,015 0,006 0.005 0.0016 0.0004 YES S4 0,220 0.42 2.27 0, 98 0,040 0, 011 0,015 0,004 0,003 0.0016 0.0016 YES S5 0.231 0.70 1.83 1,020 0,044 0, 120 0,006 0,004 0,003 0.0015 0.0005 YES S6 0,220 0.40 1.83 1.03 0,045 0,006 0,003 0,004 0.005 0.0011 0.0006 YES S7 0.231 0.40 1.90 1,400 0,025 0, 100 0,007 0,004 0,004 0.0013 0.0004 YES S8 0.215 0.41 2.23 0.970 0, 058 0.005 0,004 0,003 0,004 0.0014 0.0005 YES S9 0.222 0.40 1.80 1.01 0,045 0.10 0,003 0,004 0,004 0.0017 0.0005 YES S10 0,220 0.65 1.95 1,250 0,029 0,006 0, 019 0.005 0,003 0.0016 0.0013 YES S11 0.215 0.41 2.24 0.91 0,041 0, 11 0,004 0.005 0,003 0.0016 0.0005 YES S12 0,220 0.35 2.50 1,230 0.027 0, 005 0,017 0.005 0,003 0.0016 0.0010 YES S13 0.226 0.41 1, 81 1.03 0,003 0.005 0.001 0,003 0.005 0.0013 0.0006 NO Glow Cycle No. GT [° C] Gt [s] V [° C / s] UA T [° C] UA t [s] 1 820 60 15 375 60 2 820 60 15 375 120 3 820 60 15 375 360 4 820 60 15 425 30 5 820 60 15 425 60 6 820 60 15 425 120 7 820 60 15 450 30 8th 820 60 15 450 60 9 820 60 15 450 120 10 820 60 50 425 30 11 820 60 50 425 60 12 820 60 50 425 120 13 820 60 100 425 120 14 840 60 100 425 120 15 860 60 100 425 120 melt Glüh.Nr. WAT [° C] WET [° C] HT [° C] KWG [%] R el [MPa] R m [MPa] A 80 [%] RA [Vol%] C in RA [% by weight] Goodness RA a Ra [nm] According to the invention? K1 S1 1 1250 940 600 65 512 975 23.1 18.0 0.76 13.68 .3611 Yes K2 S1 2 1260 940 610 68 550 1002 23.7 17.0 0.78 13.26 .3612 Yes K3 S1 3 1250 930 620 63 561 963 24.6 16.5 0.81 13.37 .3614 Yes K4 S2 13 1300 930 700 63 614 1070 18.2 15.0 0.91 13.65 .3618 Yes K5 S2 14 1140 950 690 55 603 1050 23.1 15.5 0.93 14.42 .3619 Yes K6 S2 15 1250 870 400 56 580 1020 23.6 17.0 0.94 15,98 .3619 Yes K7 S3 10 1160 860 430 52 552 1103 15.5 15.0 0.65 9.75 .3607 Yes K8 S3 11 1180 870 420 55 584 1070 17.1 17.5 0.74 12.95 .3611 Yes K9 S3 12 1180 920 560 54 570 1007 18.2 18.0 0.78 14.04 .3612 Yes K10 S4 10 1190 920 560 63 509 964 16.1 15.5 0.73 11.32 .3610 Yes K11 S4 11 1170 910 550 75 592 990 18.5 18.0 0.82 14.76 .3614 Yes K12 S4 12 1260 910 530 73 548 1050 21.4 19.0 0.80 15.20 .3613 Yes K13 S4 14 1240 820 450 30 517 1035 25.6 13.0 0.95 12.35 .3620 Yes K14 S5 7 1300 940 560 54 503 981 18.1 16.5 0.78 12.87 .3612 Yes K15 S5 8th 1250 830 450 45 524 968 19.3 17.5 0.83 14.53 .3615 Yes K16 S5 9 1140 850 460 50 563 1003 20.8 18.0 0.85 15,30 .3615 Yes K17 S6 4 1150 900 500 50 532 1010 25.9 18.0 0.84 15,12 .3615 Yes K18 S6 5 1300 900 530 56 575 986 26.6 16.5 0.91 15.02 .3618 Yes K19 S6 6 1290 930 530 53 584 978 28.0 16.5 0.95 15.68 .3620 Yes K20 S7 4 1280 920 540 54 520 965 22.1 17.5 0.76 13,30 .3611 Yes K21 S7 5 1280 930 700 56 536 954 22.5 18.0 0.81 14.58 .3614 Yes K22 S7 6 1290 910 650 58 587 992 21.4 18.5 0.84 15.54 .3615 Yes K23 S8 13 1150 880 430 60 571 997 20.7 14.5 0.91 13,20 .3618 Yes K24 S8 14 1150 870 460 65 525 981 22.4 15.0 0.95 14.25 .3620 Yes K25 S8 15 1100 880 460 45 521 962 24.1 15.5 0.94 14.57 .3619 Yes K26 S9 4 1160 930 660 63 511 1009 18.7 17.0 0.77 13,09 .3612 Yes K27 S9 5 1230 950 650 62 526 1021 19.5 17.5 0.82 14.35 .3614 Yes K28 S9 6 1230 950 650 70 574 1019 21.2 18.5 0.86 15.91 .3616 Yes K29 S10 10 1170 940 680 75 510 1003 20.1 17.5 0.79 13.83 .3613 Yes K30 S10 11 1240 930 560 64 564 997 21.6 18.5 0.84 15.54 .3615 Yes K31 S10 12 1200 850 490 55 589 1011 22.2 18.5 0.88 16.28 .3617 Yes K32 S11 10 1190 860 470 46 545 1130 15.5 15.0 0.70 10.50 .3609 Yes K33 S11 11 1190 870 470 35 529 1062 16.7 17.0 0.82 13.94 .3614 Yes melt Glüh.Nr. WAT [° C] WET [° C] HT [° C] KWG [%] R el [MPa] R m [MPa] A 80 [%] RA [Vol%] C in RA [% by weight] Goodness RA a Ra [nm] According to the invention? K34 S11 12 1150 910 530 49 602 1018 18.1 18.0 0.80 14,40 .3613 Yes K35 S11 14 1160 920 520 51 608 993 23.4 13.5 0.93 12.56 .3619 Yes K36 S12 10 1140 910 520 52 542 1089 15.9 15.5 0.65 10.08 .3607 Yes K37 S12 11 1200 920 530 50 583 1054 18.1 17.0 0.63 10.71 .3606 Yes K38 S12 12 1210 930 560 49 589 1023 19.4 18.5 0.67 12.40 .3607 Yes K39 S13 7 1210 940 700 70 404 796 30.0 19.5 0.91 17.75 .3618 No K40 S13 8th 1220 860 410 45 440 763 27.0 18.0 0.93 16.74 .3619 No K41 S13 9 1230 870 420 60 453 775 25.4 17.5 0.95 16,63 .3620 No

Claims (14)

  1. Multi-phase steel containing (in % wt.) C: 0.14 - 0.25 %
    Mn: 1.7 - 2.5 %
    Si: 0.2 - 0.7 %
    Al: 0.5 - 1.5 %
    Cr: < 0.1 %
    Mo: < 0.05 %
    Nb: 0.02 - 0.06 %
    S: up to 0.01 %
    P: up to 0.02 %
    N: up to 0.01 %
    and optionally at least one element from the group "Ti, B, V" according to the following stipulation:
    Ti: up to 0.1 %
    B: up to 0.002 %
    V: up to 0.15 %
    with the remainder iron and unavoidable impurities,
    - wherein in the microstructure of the steel at least 10 % vol. ferrite and at least 6 % vol. residual austenite are present and the steel has a tensile strength Rm of at least 950 MPa, a yield point ReL of at least 500 MPa and an elongation at break A80 measured in the transverse direction of at least 15 %,
    - wherein the CinRA content of the residual austenite calculated according to formula [1] is more than 0.6 % wt.: C inRA = a RA - a γ / 0.0044
    Figure imgb0007
    with aγ: 0.3578 nm (the lattice constant of the
    austenite); aRA: the lattice parameter of the residual austenite in the finished multi-phase steel after final cooling in nm.
    - wherein the multi-phase steel has a grade GRA of the residual austenite calculated according to formula [2], for which GRA > 6 applies: G RA = % RA x C inRA
    Figure imgb0008
    with %RA: the residual austenite content of the multi-phase steel in % vol.;
    CinRA: the C content of the residual austenite
    calculated according to formula [1].
  2. Multi-phase steel according to Claim 1, characterised in that the sum of its Al and Si contents is 1.2 - 2.0 % wt.
  3. Multi-phase steel according to any one of the preceding claims, characterised in that its Si content is less than 0.6 % wt.
  4. Multi-phase steel according to any one of the preceding claims, characterised in that its Al content is 0.7 - 1.4 % wt.
  5. Multi-phase steel according to any one of the preceding claims, characterised in that its Ti content is up to 0.02 % wt.
  6. Multi-phase steel according to any one of the preceding claims, characterised in that its Ti content %Ti fulfils the condition [3]: % Ti > = 3.4 x % N
    Figure imgb0009
    with %N: the N content of the multi-phase steel.
  7. Multi-phase steel according to any one of the preceding claims, characterised in that it contains at least 0.0005 % wt. B.
  8. Multi-phase steel according to any one of the preceding claims, characterised in that it contains at least 0.06 % wt. V.
  9. Multi-phase steel according to any one of the preceding claims, characterised in that its microstructure has a martensite portion of at least 5 % vol.
  10. Multi-phase steel according to any one of the preceding claims, characterised in that its microstructure has a bainite portion of 5 to 40 % vol.
  11. Cold flat product produced from a multi-phase steel constituted according to any one of Claims 1 to 10.
  12. Method for producing a cold flat product according to Claim 11, in which the following production steps are performed:
    - melting and casting a multi-phase steel constituted according to any one of Claims 1 to 10 into a semi-finished product;
    - hot rolling the semi-finished product into a hot strip starting from an initial temperature of 1100 - 1300 °C and ending at a final temperature of 820 - 950 °C;
    - coiling the hot strip at a coiling temperature of 400 - 750 °C;
    - optionally annealing the hot strip to improve its ability to be cold rolled;
    - after coiling cold rolling the hot strip into the cold flat product at cold rolling degrees of 30 - 80 %;
    - continuously annealing the cold flat product at an annealing temperature of 750 - 900 °C;
    - optionally accelerated cooling of the continuously annealed cold flat product;
    - overageing the cold flat product at an overageing temperature of 350 - 500 °C.
  13. Method according to Claim 12, characterised in that the coiling temperature is 530 - 600 °C, the cold-rolling degree is 50 - 70 %, the annealing temperature is 800 - 830 °C or the overageing temperature is 370 - 460 °C.
  14. Method according to either of Claims 12 and 13, characterised in that the annealing optionally performed after the coiling and before the cold rolling is carried out as batch annealing or as continuous annealing at an annealing temperature of 400 - 700 °C.
EP10186553.3A 2010-10-05 2010-10-05 Multiphase steel, cold rolled flat product produced from this multiphase steel and method for producing same Active EP2439290B1 (en)

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EP10186553.3A EP2439290B1 (en) 2010-10-05 2010-10-05 Multiphase steel, cold rolled flat product produced from this multiphase steel and method for producing same
PCT/EP2011/066522 WO2012045595A1 (en) 2010-10-05 2011-09-22 Multi-phase steel, cold-rolled flat product which is produced from a multi-phase steel of this type, and method for producing it
US13/877,782 US9970088B2 (en) 2010-10-05 2011-09-22 Multi-phase steel, cold-rolled flat product produced from such a multi-phase steel and method for producing it
KR1020137011457A KR101848876B1 (en) 2010-10-05 2011-09-22 Multi-phase steel, cold-rolled flat product which is produced from a multi-phase steel of this type, and method for producing it
JP2013532112A JP6001541B2 (en) 2010-10-05 2011-09-22 Cold rolled flat steel product made from multiphase steel and its manufacturing method
CN201180048744.5A CN103210097B (en) 2010-10-05 2011-09-22 The manufacture method of multi-phase Steels, the flat cold-rolled bar goods be made up of this multi-phase Steels and this product

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102022102418A1 (en) 2022-02-02 2023-08-03 Salzgitter Flachstahl Gmbh High-strength, hot-dip coated steel strip having structural transformation-induced plasticity and method of making same

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2665798T3 (en) * 2014-07-07 2018-04-27 Tata Steel Ijmuiden Bv Steel band with high strength and high formability, the steel band has a zinc-based hot dip coating
CN104328336B (en) * 2014-11-06 2016-04-20 东北大学 Tough steel sheet of height of a kind of submicron austenite highly malleablized and preparation method thereof
CN107208209B (en) * 2015-02-20 2019-04-16 新日铁住金株式会社 Hot rolled steel plate
EP3390040B2 (en) 2015-12-15 2023-08-30 Tata Steel IJmuiden B.V. High strength hot dip galvanised steel strip
CN105886908A (en) * 2016-07-04 2016-08-24 湖南华菱湘潭钢铁有限公司 Production method of hot-rolled multiphase steel plate
BR112019000766B8 (en) 2016-08-05 2023-03-14 Nippon Steel & Sumitomo Metal Corp STEEL SHEET
US11732341B2 (en) 2016-10-19 2023-08-22 Nippon Steel Corporation Metal coated steel sheet, manufacturing method of hot-dip galvanized steel sheet, and manufacturing method of alloyed galvannealed steel sheet
CN108342656A (en) * 2018-03-13 2018-07-31 朱威威 A kind of superhigh intensity automobile structural steel and its production method
CN110724877B (en) * 2019-10-30 2021-05-28 鞍钢股份有限公司 1180MPa grade high-plasticity bainite complex phase steel plate for automobile and preparation method thereof
CN111733366B (en) * 2020-07-08 2021-06-22 马鞍山钢铁股份有限公司 Aluminum-containing cold-rolled ultrahigh-strength steel and preparation method and application thereof
SE545209C2 (en) * 2020-12-23 2023-05-23 Voestalpine Stahl Gmbh Coiling temperature influenced cold rolled strip or steel
KR20230004237A (en) * 2021-06-29 2023-01-06 현대제철 주식회사 Cold-rolled steel sheet and method of manufacturing the same
SE545181C2 (en) * 2021-07-20 2023-05-02 Voestalpine Stahl Gmbh High strength cold rolled steel strip sheet for automotive use having good withstandability to retained austentite decomposition

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01272720A (en) 1988-04-22 1989-10-31 Kobe Steel Ltd Production of high ductility and high strength steel sheet with composite structure
US6395108B2 (en) * 1998-07-08 2002-05-28 Recherche Et Developpement Du Groupe Cockerill Sambre Flat product, such as sheet, made of steel having a high yield strength and exhibiting good ductility and process for manufacturing this product
JP4414563B2 (en) 2000-06-12 2010-02-10 新日本製鐵株式会社 High-strength steel sheet excellent in formability and hole expansibility and method for producing the same
JP4085583B2 (en) 2001-02-27 2008-05-14 Ｊｆｅスチール株式会社 High-strength cold-rolled galvanized steel sheet and method for producing the same
EP1431406A1 (en) * 2002-12-20 2004-06-23 Sidmar N.V. A steel composition for the production of cold rolled multiphase steel products
JP4150277B2 (en) * 2003-03-26 2008-09-17 新日本製鐵株式会社 High strength galvannealed steel sheet excellent in press formability and method for producing the same
DE602005013442D1 (en) 2004-04-22 2009-05-07 Kobe Steel Ltd High-strength and cold-rolled steel sheet with excellent ductility and clad steel sheet
JP2005325393A (en) * 2004-05-13 2005-11-24 Jfe Steel Kk High strength cold rolled steel sheet and its manufacturing method
JP4529549B2 (en) * 2004-06-15 2010-08-25 Ｊｆｅスチール株式会社 Manufacturing method of high-strength cold-rolled steel sheets with excellent ductility and hole-expansion workability
EP2671961A1 (en) 2005-03-31 2013-12-11 Kabushiki Kaisha Kobe Seiko Sho High strength cold-rolled steel sheet and automobile components of steel having excellent properties in coating film adhesion, workability, and hydrogen embrittlement resistivity
JP5250939B2 (en) * 2005-03-31 2013-07-31 Ｊｆｅスチール株式会社 Method for producing galvannealed steel sheet
JP5213307B2 (en) * 2005-03-31 2013-06-19 Ｊｆｅスチール株式会社 Method for producing high ductility and high strength alloyed hot-dip galvanized steel sheet with excellent surface properties
KR100711475B1 (en) 2005-12-26 2007-04-24 주식회사 포스코 Method for manufacturing high strength steel strips with superior formability and excellent coatability
DE502006003833D1 (en) * 2006-10-30 2009-07-09 Thyssenkrupp Steel Ag Method for producing steel flat products from a silicon-alloyed multiphase steel
JP5352963B2 (en) * 2007-03-28 2013-11-27 Ｊｆｅスチール株式会社 High-tensile steel plate with excellent shape freezing property and manufacturing method thereof
CN101613827A (en) * 2008-06-27 2009-12-30 鞍钢股份有限公司 A kind of high-performance cold rolled phase transformation plasticity steel and preparation method thereof
KR101024800B1 (en) * 2008-08-28 2011-03-24 현대제철 주식회사 High strength hot- dip galvanized steel sheet having excellent formability and galvanizing property, and method for producing the same
CN101805871B (en) * 2010-04-09 2012-02-29 中国石油天然气集团公司 Manufacturing method of expandable casing for oil and gas well

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102022102418A1 (en) 2022-02-02 2023-08-03 Salzgitter Flachstahl Gmbh High-strength, hot-dip coated steel strip having structural transformation-induced plasticity and method of making same
WO2023148199A1 (en) 2022-02-02 2023-08-10 Salzgitter Flachstahl Gmbh High-strength hot dip-coated steel strip with plasticity brought about by microstructural transformation and method for production thereof

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