EP0914480B1 - Process for producing an easily shaped cold-rolled sheet or strip - Google Patents

Process for producing an easily shaped cold-rolled sheet or strip Download PDF

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Publication number
EP0914480B1
EP0914480B1 EP97922915A EP97922915A EP0914480B1 EP 0914480 B1 EP0914480 B1 EP 0914480B1 EP 97922915 A EP97922915 A EP 97922915A EP 97922915 A EP97922915 A EP 97922915A EP 0914480 B1 EP0914480 B1 EP 0914480B1
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maximum
cold
temperature
strip
hot
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German (de)
French (fr)
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EP0914480A1 (en
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Ilse Heckelmann
Ullrich Heidtmann
Rolf Bode
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ThyssenKrupp Steel Europe AG
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ThyssenKrupp Stahl AG
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    • 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
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • 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
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0447—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the heat treatment
    • C21D8/0473—Final recrystallisation annealing
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
    • C23C2/022—Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating
    • C23C2/0224—Two or more thermal pretreatments
    • 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
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
    • C21D8/0426—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
    • 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
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
    • C21D8/0436—Cold rolling

Definitions

  • the invention relates to a method for generating a with cold-rolled high-strength steel sheet or strip good formability, especially stretchability for Manufacture of pressed parts with high dent resistance.
  • the pressed parts should have a high basic material strength have and after an additional heat treatment, such as it is usually used for painting, one additional material hardening ("bake hardening") receive. This gives excellent buckling stiffness properties reached.
  • Pressed parts with high Stretch-drawing components are e.g. flat body parts in the Automotive industry, such as doors, hoods, roofs.
  • An unalloyed LC steel can be used in continuous furnaces Have aging parts in line, also as bake-hardening Steel can be produced by chemical Steel composition, cooling rate and aging condition be precisely coordinated. This The process is already being used on an industrial scale.
  • a Optimization of the generation conditions is e.g. of Hayashida et al. (T. Hayashida, M. Oda, T. Yamada, Y. Matsukawa, J. Tanaka: "Development and applications of continuous-annealed low-carbon Al-killed BH steel sheets ", Poc. Of the Symp. On High-Strength Sheet steels for the Automotive Industry, Baltimore, October 16-19, 1994, p.135).
  • low-carbon steels so-called ultra-low-carbon (ULC) steels
  • ULC ultra-low-carbon
  • the carbon content should be between 15 and 25 ppm.
  • the titanium content is adjusted to the nitrogen and sulfur contents with 48/14 N ⁇ Ti ⁇ 48 (N / 14 + S / 32).
  • the aim is to completely bind the nitrogen in titanium nitrides, but to ensure the bake-hardening effect, a small amount of carbon must remain in solution. Generation in vacuum degassing plants is necessary.
  • the advantage of this process is that there is no aging annealing, which makes it suitable for hot-dip coating systems.
  • the bake-hardening parameters determined in the tensile test after 2% pre-stretching (BH 2 value) reach approximately 40 N / mm 2 for the steels produced in this way.
  • the yield strengths are around 200 N / mm 2
  • the values for the mean vertical anisotropy (r value) are around 1.8.
  • EP 0 620 288 A1 discloses a process for producing only cold-rolled or fire-coated cold-rolled steel strip in continuous strip lines, which, in addition to being resistant to aging, has high bake-hardening properties and good deep-drawing properties due to high r values.
  • a ULC steel itself or a ULC steel is annealed with either a titanium or a niobium alloy above the Ac 3 transformation temperature, ie in the austenite area.
  • the bake-hardening values in this process reach 100 N / mm 2 .
  • An aging glow is not necessary.
  • ULC steel the steel must be manufactured in a vacuum degassing plant. Difficulties with regard to strip flatness are caused by the high annealing temperatures required in this process. A large-scale application of this method is not known.
  • processes previously used or described in the literature for the production of readily deformable cold sheet with bake-hardening properties in continuous strip systems either include the additional annealing treatment described above in the case of using a soft, unalloyed A1-soaked deep-drawing steel, which is a production in a common one Fire coating system is not allowed, or the more complex to produce ULC steels with very low carbon contents must be used.
  • the above-described methods based on ULC steels mainly include steels with yield strengths in the lower range up to 240 N / mm 2 . Due to the high average r-values (> 1.5), they are suitable for pressed parts with a high proportion of deep-drawn parts.
  • thermomechanical Rolling of Hot strip made of microalloyed structural steels steel and iron 111 (1991) No. 5, known, thermomechanically rolled To produce hot strips from low-pearlite special structural steels.
  • the hot strips are due to low alloy contents high yield strength and good cold formability characterized.
  • To influence the grain size are the Steels added to the nitrogen setting Ti and Nb. The Levels of these alloying elements are in each case well above the stoichiometric setting of the Amount of nitrogen required.
  • EP 0 432 498 B1 describes a method for Production of a high tensile strength cold-rolled steel sheet known, which a has improved stretch flanging properties.
  • the Sheet steel has to produce a uniform, fine structure contents of Nb in the range from 0.005 to 0.045%.
  • Manufactured by the known method Steel sheets have high cold-rolled condition Tensile strengths so that they can only be applied relatively high forces can be deformed. Due to their high strength, the after known methods produced sheets in particular for Manufacture of rust-resistant reinforcement elements suitable for automobiles.
  • the task is derived from this ab, a well formable, high-strength cold-rolled Steel sheet or strip in a continuous Belt plant without a subsequent aging annealing treatment manufacture aging-resistant, which also has good bake hardening properties.
  • the combination of the high basic material strength and The bake hardening potential is said to be excellent Bulge stiffness of the pressed parts.
  • the steel achieves its aging resistance through a titanium addition matched to the nitrogen content. This leads to an early complete setting of nitrogen, which as a the aging resistance severely impairing element is known.
  • the Aging tests see examples below
  • the volume fraction and however, the number of titanium carbides must never be increased be high so that the steel is used for high forming requirements necessary hardening characteristics and sufficient stretch and toughness properties has. Therefore, the amount of nitrogen should not bound nitride formers are 0.003 to 0.015% Ti. This limitation of the amount of nitride is guaranteed uniform mechanical properties that opposite process-related fluctuations in hot strip temperature control (Influencing the excretion distribution) are largely invariant.
  • the silicon content should be used for hot-dip galvanized sheet preferably to max. 0.15% may be limited.
  • the economic advantage of the method according to the invention is that the additional process step aging annealing to achieve aging resistance not applicable, although the steel composition Based on the analysis of soft, unalloyed Al-calmed (LC) steels based. Steel production can be due to this Analysis concept without complex metallurgical production processes respectively. In addition, Titan is only in small amounts needed, so the steel too with regard to the alloy additions generate is.
  • the cold strip should preferably be at a speed in Range from 5 to 10 K / s on the temperature of the recrystallization annealing be heated.
  • the recrystallizing Annealing can preferably be in line with one Hot dip galvanizing plant can be made.
  • the steel strips or sheets produced by the process according to the invention are distinguished by an initial yield point (greater than 240 N / mm 2 ) which is favorable with regard to the subsequent deformation and a high strengthening capacity in the range of small plastic expansions. Together with low values of the vertical anisotropy, which characterize a preferred flow from the thickness, pressed parts with a high stretch-drawing proportion, for example automobile outer skin parts, are the ideal area of application.
  • the strong solidification of this material which occurs even with small plastic deformations and is expressed in very high work hardening values, is an essential point for the properties of the product. The strong solidification favors the transmission of force to neighboring material areas, which prevents local premature material failure, eg constriction.
  • the material can therefore flow more evenly over the entire surface of the pressed part.
  • the small differences in the r values depending on the angle to the rolling direction have a favorable effect on uniform forming behavior. This isotropic behavior is evidenced by small values of the planar anisotropy.
  • the slabs produced by continuous casting according to the invention manufactured steels A and B, their chemical Compositions listed in Table 1 were found in reheated in a pusher furnace to temperatures of approx. 1200 ° C and to final thicknesses of 2.8 - 3.3 mm above the
  • Ar 3 temperature hot rolled Ar 3 temperature hot rolled.
  • the finish rolling and reel temperatures are shown in Table 2.
  • Two reel temperature classes were used for the strips of steels A and B: 730 ° C (steels A1 and B1) and 600 ° C (steels A2 and B2).
  • the strips were cold-rolled with degrees of deformation between 65 and 75% to thicknesses between 0.8 and 1.0 mm and then first recrystallized in a hot-dip coating plant and then hot-dip galvanized.
  • the strip temperature in the recrystallization furnace was 800 ° C.
  • the cooling rates after the recrystallizing annealing were between 10 and 50 K / s.
  • the galvanized belts were treated with 1.8% and were then free from elongation limit.
  • the BH 0 value corresponds to the increase in the lower yield strength after a heat treatment of 20 minutes at 170 ° C.
  • the size WH indicates the amount of deformation hardening when the tensile test is stretched by 2%. It is calculated by subtracting the yield strength Rp 0.2 from the measured stress at 2% deformation.
  • the size BH 2 corresponds to the increase in the lower yield strength after a heat treatment of 20 minutes at 170 ° C, measured on the 2% pre-stretched tensile test.
  • the hot-dip galvanized cold-rolled strips made of steels A and B show an almost unchanged level of the lower or upper yield strength after artificial aging of 60 minutes at 100 ° C (Table 3).
  • the extent of the yield point elongation also remains below 0.5%, which means that the aging resistance is sufficient for processing without flow figures even after long periods of storage.
  • the course of the differential (instantaneous) hardening exponent (n value) over the total strain is plotted in FIG. 1 for steel A1 (reel temperature 730 ° C.) and in FIG. 2 for steel A2 (reel temperature 600 ° C.).
  • the maxima of the differential n values are listed in Table 2; For steels A and B, they reach at least 0.170 for both reel temperature classes, and at least 0.180 for high reel temperatures.
  • the n value maximum of steels A and B is in the range of low total strains between 2 and 5%.
  • the yield strengths are approximately 50 N / mm 2 larger for the higher-coiled variants A1 and B1 than for the low-coiled variants A2 and B2, so that the starting position of the yield strength can be determined by the choice of the coiling temperature.
  • the values for the mean vertical anisotropy for the steels A1, A2, B1 and B2 according to the invention are low at 1.0-1.1.
  • the reel temperature Regardless of the reel temperature, they have isotropic properties with ⁇ r values between 0 and 0.3.
  • the work-hardening values which are a measure of the hardening by plastic deformation, are very high at approx. 50 N / mm 2 .
  • the parameters for bake hardening with or without pre-deformation in all cases reach at least 45 N / mm 2 .
  • the increase in yield strength after the painting treatment of a pressed part can be estimated by the sum WH + BH 2 .
  • At high reel temperatures (steels A1 and B1) these values are at least 100 N / mm 2 .
  • the sum WH + BH 2 with at least 60 N / mm 2 is still cheap.
  • Tables 1, 2 and 3 also list steels C to E for comparison, which, in contrast to steels A and B, either contain no titanium (steel E) or have titanium contents that are substoichiometric in relation to the nitrogen content (steels C and D with Ti / N ⁇ 3.4).
  • the increase in the lower yield strength (R e1 ) and the yield strength expansions after artificial aging are significantly higher in these comparative steels than in the steels A and B produced according to the invention.
  • the upper yield strength (deer) increases

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  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
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Abstract

PCT No. PCT/EP97/02169 Sec. 371 Date Oct. 27, 1998 Sec. 102(e) Date Oct. 27, 1998 PCT Filed Apr. 26, 1997 PCT Pub. No. WO97/46720 PCT Pub. Date Dec. 11, 1997A method for producing a cold-rolled steel sheet or strip with good formability, especially stretch formability, for making pressings with a high buckling resistance from a steel comprising (in % by mass): 0.01 to 0.08% C, 0.10 to 0.80% Mn, maximum 0.15% Si, 0.015 to 0.08% Al, a maximum 0.005% N, 0.01 to 0.04% Ti and/or Nb, whose contents exceeding the quantity necessary for stoichiometric binding of the nitrogen, ranges from 0.003 to 0.015% Ti or 0.0015 to 0.008% Nb, and a maximum 0.15% in total of one or several elements from the group copper, vanadium, nickel, the remainder being iron, including unavoidable impurities, including a maximum 0.08% P and a maximum 0.02% S, comprises preheating the cast slab to a temperature exceeding 1050 DEG C., hot-rolling at a final temperature ranging from over the Ar3 temperature to 950 DEG C., coiling the hot-rolled strip at a temperature ranging from 550 to 750 DEG C., cold-rolling at a total cold-rolling degree of deformation from 40 to 85%, recrystallization annealing of the cold strip in a continuous furnace at a temperature of at least 720 DEG C., subsequent cooling at 5 to 70 K/s; and skin passing.

Description

Die Erfindung betrifft ein Verfahren zur Erzeugung eines kaltgewalzten höherfesten Stahlbleches oder -bandes mit guter Umformbarkeit, insbesondere Streckziehbarkeit zur Herstellung von Preßteilen mit hoher Beulsteifigkeit.The invention relates to a method for generating a with cold-rolled high-strength steel sheet or strip good formability, especially stretchability for Manufacture of pressed parts with high dent resistance.

Die Preßteile sollen eine hohe Materialgrundfestigkeit haben und nach einer zusätzlichen Wärmebehandlung, wie sie üblicherweise beim Lackieren angewendet wird, eine zusätzliche Materialverfestigung ("Bake-hardening") erhalten. Dadurch werden hervorragende Beulsteifigkeitseigenschaften erreicht. Preßteile mit hohem Streckziehanteil sind z.B. flache Karosserieteile in der Automobilindustrie, wie Türen, Hauben, Dächer.The pressed parts should have a high basic material strength have and after an additional heat treatment, such as it is usually used for painting, one additional material hardening ("bake hardening") receive. This gives excellent buckling stiffness properties reached. Pressed parts with high Stretch-drawing components are e.g. flat body parts in the Automotive industry, such as doors, hoods, roofs.

Bei der Herstellung von durchlaufgeglühten Al-beruhigten unlegierten Tiefziehstählen mit besonderen Umformansprüchen wird nach Abkühlung von Rekristallisationstemperatur eine zusätzliche Glühung, die sogenannte überalterungsglühung, angewendet um Alterungsbeständigkeit zu gewährleisten. Ein alterungsbeständiger Werkstoff ist dadurch gekennzeichnet, daß auch nach längeren Lagerzeiten keine nennenswerten Veränderungen der Werkstoffeigenschaften auftreten und eine fehlerfreie, fließfigurenfreie Weiterverarbeitung möglich ist. In einem Durchlaufofen kann diese Behandlung in einem Überalterungsteil der Linie erfolgen. Bei Bändern, die in einer gängigen Feuerbeschichtungsanlage erzeugt werden, muß eine anschließende externe Glühung, üblicherweise im Bund, durchgeführt werden. Der Gehalt an Kohlenstoff liegt bei den Al-beruhigten unlegierten Tiefziehstählen, auch "Lowcarbon" (LC)-Stähle genannt, im Bereich 0,02 bis 0,08%.In the production of continuous annealed Al-calm unalloyed deep-drawing steels with special forming requirements after cooling of Recrystallization temperature an additional annealing, the so-called aging annealing applied around To ensure aging resistance. On This makes the material resistant to aging characterized in that even after long periods of storage noteworthy changes in material properties occur and a flawless, flow figure-free Further processing is possible. In a continuous furnace can this treatment in an aging part of the Line. For tapes in a common Fire coating system must be generated subsequent external annealing, usually in the collar, be performed. The carbon content is included Al-calmed unalloyed deep-drawing steels, also "low carbon" Called (LC) steels, in the range 0.02 to 0.08%.

Vor allem für den Automobilkarosseriebau ist aus Gründen der Gewichtseinsparung der Einsatz von möglichst dünnem Blech erwünscht. Um die erforderlichen Beulsteifigkeiten trotz Dickenreduzierung der Bleche zu gewährleisten, sind höhere Festigkeiten notwendig. Hierfür finden Bake-hardening Stähle zunehmend Einsatz. Stähle mit Bake-hardening Eigenschaften zeichnen sich durch eine zusätzliche Streckgrenzensteigerung am gezogenen Bauteil aus. Diese wird dadurch erreicht, daß der Werkstoff neben der beim Pressen auftretenden Verformungsverfestigung ("Work-hardening") noch eine zusätzliche Festigkeitssteigerung beim Einbrennlackieren, dem "Bake-hardening", erfährt. Die physikalische Ursache ist eine kontrolliert ablaufende Kohlenstoffalterung. Für Bake-hardening Stähle und deren Anwendungsgebiet ist eine ausreichende Alterungsbeständigkeit für fehlerfreie Oberflächen nach dem Verpressen ebenfalls notwendig.Especially for automobile body construction is for reasons the weight saving the use of the thinnest possible Sheet metal desired. To the required buckling stiffness to be guaranteed despite the reduction in thickness of the sheets higher strengths necessary. For this you will find bake hardening Steels are increasingly used. Steels with bake hardening Characteristics are characterized by a additional increase in yield strength on the drawn component out. This is achieved in that the material in addition the deformation hardening that occurs during pressing ("Work-hardening") an additional increase in strength with stove enamelling, "bake hardening", experiences. The physical cause is controlled ongoing carbon aging. For bake-hardening steels and their field of application is sufficient Resistance to aging for flawless surfaces pressing is also necessary.

Ein unlegierter LC-Stahl kann in Durchlauföfen, die einen Überalterungsteil in Linie besitzen, auch als Bake-hardening Stahl erzeugt werden, indem chemische Stahlzusammensetzung, Abkühlrate und Überalterungsbedingung genau aufeinander abgestimmt werden. Dieses Verfahren wird bereits großtechnisch angewendet. Eine Optimierung der Erzeugungsbedingungen wird z.B. von Hayashida et al. (T. Hayashida, M. Oda, T. Yamada, Y. Matsukawa, J. Tanaka: "Development and applications of continuous-annealed low-carbon Al-killed BH steel sheets", Poc. of the Symp. on High-Strength Sheet steels for the Automotive Industry, Baltimore, October 16-19, 1994, p.135) beschrieben.An unalloyed LC steel can be used in continuous furnaces Have aging parts in line, also as bake-hardening Steel can be produced by chemical Steel composition, cooling rate and aging condition be precisely coordinated. This The process is already being used on an industrial scale. A Optimization of the generation conditions is e.g. of Hayashida et al. (T. Hayashida, M. Oda, T. Yamada, Y. Matsukawa, J. Tanaka: "Development and applications of continuous-annealed low-carbon Al-killed BH steel sheets ", Poc. Of the Symp. On High-Strength Sheet steels for the Automotive Industry, Baltimore, October 16-19, 1994, p.135).

In anderen Verfahren zur Erzeugung von alterungsbeständigen kaltgewalzten Stählen mit Bake-hardening Eigenschaften in kontinuierlichen Bandanlagen werden niedrig gekohlte Stähle, sogenannte Ultra-low-carbon (ULC) Stähle, verwendet. N. Mizui, A. Okamoto, T. Tanioku: "Recent Development in Bake-hardenable Sheet Steel for Automotive Body Panels"; Internationale Tagung "Stahl im Automobilbau", Würzburg 24.-26.9.1990) beschreiben ein Verfahren auf Basis eines mit Titan teilstabilisierten ULC-Stahles für Feuerbeschichtungsanlagen. Der Kohlenstoffgehalt soll zwischen 15 und 25 ppm liegen. Der Titangehalt wird den Stickstoff- und Schwefelgehalten mit 48/14 N < Ti < 48 (N/14+S/32) angepaßt. Ziel ist die vollständige Abbindung des Stickstoffs in Titannitriden, wobei jedoch zur Gewährleistung des Bake-hardening Effektes eine geringe Menge an Kohlenstoff in Lösung bleiben muß. Eine Erzeugung in Vakuumentgasungsanlagen ist notwendig. Vorteil dieses Verfahrens ist der Wegfall der Überalterungsglühung, wodurch eine Eignung für Feuerbeschichtungsanlagen gegeben ist. Die im Zugversuch ermittelten Bake-hardening Kenngrößen nach 2 % Vordehnung (BH2-Wert) erreichen bei den so hergestellten Stählen cirka 40 N/mm2. Die Streckgrenzen liegen bei ca. 200 N/mm2, die Werte für die mittlere senkrechte Anisotropie (r-Wert) bei ca. 1,8. In other processes for the production of aging-resistant cold-rolled steels with bake-hardening properties in continuous belt systems, low-carbon steels, so-called ultra-low-carbon (ULC) steels, are used. N. Mizui, A. Okamoto, T. Tanioku: "Recent Development in Bake-hardenable Sheet Steel for Automotive Body Panels"; International conference "Steel in Automotive Engineering", Würzburg, September 24-26, 1990) describes a process based on a titanium partially stabilized ULC steel for hot-dip coating systems. The carbon content should be between 15 and 25 ppm. The titanium content is adjusted to the nitrogen and sulfur contents with 48/14 N <Ti <48 (N / 14 + S / 32). The aim is to completely bind the nitrogen in titanium nitrides, but to ensure the bake-hardening effect, a small amount of carbon must remain in solution. Generation in vacuum degassing plants is necessary. The advantage of this process is that there is no aging annealing, which makes it suitable for hot-dip coating systems. The bake-hardening parameters determined in the tensile test after 2% pre-stretching (BH 2 value) reach approximately 40 N / mm 2 for the steels produced in this way. The yield strengths are around 200 N / mm 2 , the values for the mean vertical anisotropy (r value) are around 1.8.

Für die Darstellung solcher mit Titan teilstabilisierten ULC-Stähle liegen nach W. Bleck, R. Bode, 0. Maid,For the representation of those partially stabilized with titanium ULC steels are based on W. Bleck, R. Bode, 0. Maid,

L. Meyer: "Metallurgical Design of High-Strength ULC Steels", Proc. of the Symp. on High-Strength Sheet Steels for the Automotive Industry, Baltimore, October 16-19, 1994) die Titangehalte zwischen dem 0,6- und 3,4-fachen des Stickstoffgehaltes. Der Gesamtgehalt an Kohlenstoff und Stickstoff soll 50 ppm nicht überschreiten.L. Meyer: "Metallurgical Design of High-Strength ULC Steels ", Proc. Of the Symp. On High-Strength Sheet Steels for the Automotive Industry, Baltimore, October 16-19, 1994) the titanium content between 0.6 and 3.4 times the nitrogen content. The total carbon content and nitrogen should not exceed 50 ppm.

Die EP 0 620 288 A1 offenbart ein Verfahren zur Herstellung eines nur kaltgewalzten oder feuerbeschichteten kaltgewalzten Stahlbandes in kontinuierlichen Bandanlagen, das neben der Alterungsbeständigkeit hohe Bake-hardening Eigenschaften und aufgrund hoher r-Werte gute Tiefzieheigenschaften besitzt. Hierbei wird ein ULC-Stahl selbst oder ein ULC-Stahl mit entweder einer Titan- oder einer Nioblegierung oberhalb der Ac3-Umwandlungstemperatur, d.h. im Austenitgebiet, geglüht. Die Bake-hardening Werte erreichen bei diesem Verfahren 100 N/mm2. Eine Überalterungsglühung ist nicht notwendig. Als ULC-Stahl muß die Stahlherstellung in einer Vakuumentgasungsanlage erfolgen. Schwierigkeiten hinsichtlich der Bandebenheit bereiten bei diesem Verfahren die notwendigen hohen Glühtemperaturen. Eine großtechnische Anwendung dieses Verfahrens ist nicht bekannt.EP 0 620 288 A1 discloses a process for producing only cold-rolled or fire-coated cold-rolled steel strip in continuous strip lines, which, in addition to being resistant to aging, has high bake-hardening properties and good deep-drawing properties due to high r values. Here, a ULC steel itself or a ULC steel is annealed with either a titanium or a niobium alloy above the Ac 3 transformation temperature, ie in the austenite area. The bake-hardening values in this process reach 100 N / mm 2 . An aging glow is not necessary. As ULC steel, the steel must be manufactured in a vacuum degassing plant. Difficulties with regard to strip flatness are caused by the high annealing temperatures required in this process. A large-scale application of this method is not known.

In Bleck et al. a.a.O. wird darauf hingewiesen, daß die Erzeugung eines alterungsbeständigen Stahles mit guten Umformeigenschaften auf Basis unlegierter LC-Stähle in kontinuierlichen Bandanlagen ohne eine Überalterung nicht möglich ist. Da der Abkühlprozeß in gängigen Feuerbeschichtungsanlagen aufgrund der Schmelztaucheinrichtung eingeschränkt ist, kann hier eine Überalterungsglühung in Linie, wie oben erwähnt, nicht stattfinden. Die Erzeugung alterungsbeständiger Stähle mit Bake-hardening-Eigenschaften in Feuerbeschichtungsanlagen beschränkt sich daher nach bisherigem Stand der Technik ausschließlich auf ULC-Stähle. Somit beinhalten bisher angewendete oder in der Literatur beschriebene Verfahren zur Herstellung von gut umförmbarem Kaltfeinblech mit Bake-hardening-Eigenschaften in kontinuierlichen Bandanlagen entweder die oben beschriebene zusätzliche Gühbehandlung für den Fall der Verwendung eines weichen unlegierten A1-beruhigten Tiefziehstahles, was eine Erzeugung in einer gängigen Feuerbeschichtungsanlage nicht erlaubt, oder es müssen die aufwendiger herzustellenden ULC-Stähle mit sehr geringen Kohlenstoffgehalten verwendet werden. Die oben beschriebenen Verfahren auf Basis der ULC-Stähle umfassen hauptsächlich Stähle mit Streckgrenzen im unteren Bereich bis 240 N/mm2. Aufgrund der hohen mittleren r-Werte (> 1,5) eignen sie sich für Preßteile mit hohem Tiefziehanteil.In Bleck et al. As mentioned above, it is pointed out that the production of an aging-resistant steel with good forming properties based on unalloyed LC steels in continuous belt systems is not possible without aging. Since the cooling process in conventional hot-dip coating systems is restricted due to the hot-dip device, an aging annealing in line, as mentioned above, cannot take place here. The production of aging-resistant steels with bake-hardening properties in hot-dip coating plants is therefore limited to ULC steels according to the current state of the art. Thus, processes previously used or described in the literature for the production of readily deformable cold sheet with bake-hardening properties in continuous strip systems either include the additional annealing treatment described above in the case of using a soft, unalloyed A1-soaked deep-drawing steel, which is a production in a common one Fire coating system is not allowed, or the more complex to produce ULC steels with very low carbon contents must be used. The above-described methods based on ULC steels mainly include steels with yield strengths in the lower range up to 240 N / mm 2 . Due to the high average r-values (> 1.5), they are suitable for pressed parts with a high proportion of deep-drawn parts.

Neben dem voranstehend erläuterten Stand der Technik ist es aus dem Artikel "Thermomechanisches Walzen von Warmband aus mikrolegierten Baustählen", Stahl u. Eisen 111 (1991) Nr. 5, bekannt, thermomechanisch gewalzte Warmbänder aus perlitarmen Sonderbaustählen zu erzeugen. Die Warmbänder sind durch geringe Legierungsgehalte bei hohem Streckgrenzniveau und einer guten Kaltumformbarkeit gekennzeichnet. Zur Beeinflussung der Korngröße sind den Stählen zur Stickstoffabbindung Ti und Nb zugegeben. Die Gehalte dieser Legierungselemente liegen dabei jeweils deutlich oberhalb der zur stöchiometrischen Abbindung des Stickstoffs benötigten Menge. In addition to the prior art explained above it from the article "Thermomechanical Rolling of Hot strip made of microalloyed structural steels ", steel and iron 111 (1991) No. 5, known, thermomechanically rolled To produce hot strips from low-pearlite special structural steels. The hot strips are due to low alloy contents high yield strength and good cold formability characterized. To influence the grain size are the Steels added to the nitrogen setting Ti and Nb. The Levels of these alloying elements are in each case well above the stoichiometric setting of the Amount of nitrogen required.

Aus der EP 0 432 498 B1 ist schließlich ein Verfahren zur Herstellung eines eine hohe Zugfestigkeit aufweisenden kaltgewalzten Stahlblechs bekannt, welches eine verbesserte Streckbördeleigenschaft besitzt. Das Stahlblech weist zur Erzeugung eines einheitlichen, feinen Gefüges Gehalte an Nb im Bereich von 0,005 bis 0,045 % auf. Nach dem bekannten Verfahren hergestellte Stahlbleche weisen im kaltgewalzten Zustand hohe Zugfestigkeiten auf, so daß sie nur durch Aufbringen verhältnismäßig hoher Kräfte verformt werden können. Aufgrund ihrer hohen Festigkeit sind die nach dem bekannten Verfahren erzeugten Bleche insbesondere zur Herstellung von rost-beständigen Verstärkungselementen von Automobilen geeignet. Daraus leitet sich die Aufgabe ab, ein gut umformbares höherfestes kaltgewalztes Stahlblech oder -band in einer kontinuierlichen Bandanlage ohne eine nachfolgende Überalterungsglühbehandlung alterungsbeständig herzustellen, das außerdem gute Bake-hardening-Eigenschaften besitzt. Die Kombination der hohen Werkstoffgrundfestigkeit und dem Bake-hardening Potential soll zu ausgezeichneten Beulsteifigkeiten der Preßteile führen.Finally, EP 0 432 498 B1 describes a method for Production of a high tensile strength cold-rolled steel sheet known, which a has improved stretch flanging properties. The Sheet steel has to produce a uniform, fine structure contents of Nb in the range from 0.005 to 0.045%. Manufactured by the known method Steel sheets have high cold-rolled condition Tensile strengths so that they can only be applied relatively high forces can be deformed. Due to their high strength, the after known methods produced sheets in particular for Manufacture of rust-resistant reinforcement elements suitable for automobiles. The task is derived from this ab, a well formable, high-strength cold-rolled Steel sheet or strip in a continuous Belt plant without a subsequent aging annealing treatment manufacture aging-resistant, which also has good bake hardening properties. The combination of the high basic material strength and The bake hardening potential is said to be excellent Bulge stiffness of the pressed parts.

Zur Lösung dieser Aufgabe wird ein Verfahren zur Erzeugung eines kaltgewalzten Stahlbleches oder -bandes mit guter Umformbarkeit, insbesondere Streckziehbarkeit zur Herstellung von Preßteilen mit hoher Beulsteifigkeit aus einem Stahl folgender Zusammensetzung (in Masse-%) :

  • C: 0,01 - 0,08 %,
  • Mn: 0,10 - 0,80 %,
  • Si: max. 0,60 %,
  • Al: 0,015 - 0,08 %,
  • N: max. 0,005 %,
  • Ti: 0,01 - 0,04 %, wobei der über die zur stöchiometrischen Abbindung von Stickstoff notwendige Menge hinausgehende Gehalt im Bereich von 0,003 bis 0,015 % Ti liegt,
    • ferner max. 0,15 % insgesamt eines oder mehrerer aus der Gruppe Kupfer, Vanadium, Nickel, Rest Eisen und unvermeidbare Verunreinigungen, einschließlich max. 0,08 % P, max. 0,02 % S,
    vorgeschlagen, bestehend aus
    • Vorwärmen der gegossenen Bramme auf eine Temperatur oberhalb von 1050 °C,
    • Warmwalzen mit einer Endtemperatur im Bereich von oberhalb Ar3 bis 950 °C,
    • Haspeln des warmgewalzten Bandes bei einer Temperatur im Bereich von 550 bis 750 °C,
    • Kaltwalzen mit einem Gesamtverformungsgrad von 40 bis 85 %,
    • rekristallisierendem Glühen des Kaltbandes bei einer Temperatur von mind. 720 °C in einem Durchlaufofen,
    • Abkühlen mit Abkühlraten von 5 bis 70 K/s und
    • abschließendem Dressieren.
    To solve this problem, a method for producing a cold-rolled steel sheet or strip with good formability, in particular stretchability for producing pressed parts with high buckling stiffness from a steel of the following composition (in mass%):
  • C: 0.01-0.08%,
  • Mn: 0.10 - 0.80%,
  • Si: max. 0.60%,
  • Al: 0.015 - 0.08%,
  • N: max. 0.005%,
  • Ti: 0.01-0.04%, the content going beyond the amount necessary for the stoichiometric setting of nitrogen in the range from 0.003 to 0.015% Ti,
    • furthermore max. 0.15% in total of one or more from the group copper, vanadium, nickel, remainder iron and unavoidable impurities, including max. 0.08% P, max. 0.02% S,
    proposed consisting of
    • Preheating the cast slab to a temperature above 1050 ° C,
    • Hot rolling with a final temperature in the range from above Ar 3 to 950 ° C,
    • Coiling the hot-rolled strip at a temperature in the range from 550 to 750 ° C,
    • Cold rolling with a total degree of deformation of 40 to 85%,
    • recrystallizing annealing of the cold strip at a temperature of at least 720 ° C in a continuous furnace,
    • Cooling down with cooling rates from 5 to 70 K / s and
    • final skin training.

    Seine Alterungsbeständigkeit erreicht der Stahl durch eine auf den Stickstoffgehalt abgestimmte Titanzugabe. Diese führt zu einer frühzeitigen vollständigen Abbindung des Stickstoffs, der als ein die Alterungsbeständigkeit stark beeinträchtigendes Element bekannt ist. In den Alterungsuntersuchungen (siehe nachfolgende Beispiele) wurde festgestellt, daß eine ausreichende Alterungsbeständigkeit dann besteht, wenn eine über die zur Stickstoffabbindung hinausgehende Menge an Titan vorhanden ist, so daß die Bildung einer Mindestmenge an Titankarbiden gewährleistet ist. Der Volumenanteil und die Zahl an Titankarbiden dürfen jedoch keinesfalls zu hoch sein, damit der Stahl die für den hohen Umformanspruch notwendige Verfestigungscharakteristik und ausreichende Dehnungs- und Zähigkeitseigenschaften besitzt. Daher sollte die Menge des nicht an Stickstoff gebundenen Nitridbildners 0,003 bis 0,015 % Ti liegen. Diese Begrenzung der Nitridbildnermenge gewährleistet gleichmäßige mechanische Eigenschaften, die gegenüber prozeßbedingten Schwankungen in der Warmbandtemperaturführung (Beeinflussung der Ausscheidungsverteilung) weitgehend invariant sind.The steel achieves its aging resistance through a titanium addition matched to the nitrogen content. This leads to an early complete setting of nitrogen, which as a the aging resistance severely impairing element is known. In the Aging tests (see examples below) it has been found that adequate aging resistance then exists if one over the for Amount of titanium exceeding nitrogen is present so that the formation of a minimum amount Titanium carbides is guaranteed. The volume fraction and however, the number of titanium carbides must never be increased be high so that the steel is used for high forming requirements necessary hardening characteristics and sufficient stretch and toughness properties has. Therefore, the amount of nitrogen should not bound nitride formers are 0.003 to 0.015% Ti. This limitation of the amount of nitride is guaranteed uniform mechanical properties that opposite process-related fluctuations in hot strip temperature control (Influencing the excretion distribution) are largely invariant.

    Bei Anwendung dieses Analysenkonzeptes ist sichergestellt, daß nach Abkühlung von Rekristallisationstemperatur genügend Kohlenstoff in gelöster Form vorhanden ist, damit gute Bake-hardening Eigenschaften vorliegen.When using this analysis concept, it is ensured that that after cooling from recrystallization temperature enough carbon in dissolved form is present for good bake-hardening properties available.

    Der Siliziumgehalt sollte für feuerverzinktes Feinblech vorzugsweise auf max. 0,15 % begrenzt sein.The silicon content should be used for hot-dip galvanized sheet preferably to max. 0.15% may be limited.

    Der wirtschaftliche Vorteil des erfindungsgemäßen Verfahrens besteht darin, daß der zusätzliche Prozeßschritt der Überalterungsglühung zum Erreichen der Alterungsbeständigkeit entfällt, obwohl die Stahlzusammensetzung auf Basis der Analyse weicher unlegierter Al-beruhigter (LC)-Stähle beruht. Die Stahlerzeugung kann aufgrund dieses Analysenkonzeptes ohne aufwendige metallurgische Erzeugungsverfahren erfolgen. Außerdem wird Titan nur in geringen Mengen benötigt, so daß der Stahl auch hinsichtlich der Legierungszugaben kostengünstig zu erzeugen ist.The economic advantage of the method according to the invention is that the additional process step aging annealing to achieve aging resistance not applicable, although the steel composition Based on the analysis of soft, unalloyed Al-calmed (LC) steels based. Steel production can be due to this Analysis concept without complex metallurgical production processes respectively. In addition, Titan is only in small amounts needed, so the steel too with regard to the alloy additions generate is.

    Das Herstellungsverfahren des Stahls umfaßt das

    • Vorwärmen der gegossenen Bramme auf eine Temperatur oberhalb von 1050 °C,
    • Warmwalzen mit einer Endtemperatur im Bereich von > Ar3 bis 950 °C,
    • Haspeln des warmgewalzten Bandes im Temperaturbereich von 550 bis 750 °C,
    • Kaltwalzen mit einem Gesamtverformungsgrad von 40 bis 85%,- Rekristallisierendes Glühen des Kaltbandes bei mindestens 720 °C in einem Durchlaufofen
    • Abkühlen mit Abkühlraten von 5 bis 70 K/s und
    • Dressieren.
    The steel manufacturing process includes this
    • Preheating the cast slab to a temperature above 1050 ° C,
    • Hot rolling with a final temperature in the range of> Ar 3 to 950 ° C,
    • Coiling of the hot-rolled strip in the temperature range from 550 to 750 ° C,
    • Cold rolling with a total degree of deformation of 40 to 85%, - recrystallizing annealing of the cold strip at at least 720 ° C in a continuous furnace
    • Cooling down with cooling rates from 5 to 70 K / s and
    • Temper rolling.

    Bevorzugt soll das Kaltband mit einer Geschwindigkeit im Bereich von 5 bis 10 K/s auf die Temperatur der Rekristallisationsglühung erhitzt werden. Das rekristallisierende Glühen kann bevorzugt in Linie mit einer Feuerverzinkungsanlage vorgenommen werden.The cold strip should preferably be at a speed in Range from 5 to 10 K / s on the temperature of the recrystallization annealing be heated. The recrystallizing Annealing can preferably be in line with one Hot dip galvanizing plant can be made.

    Die nach dem erfindungsgemäßen Verfahren hergestellten Stahlbänder oder -bleche zeichnen sich durch eine im Hinblick auf die anschließende Verformung günstige Ausgangsstreckgrenze (größer 240 N/mm2) und ein hohes Verfestigungsvermögen im Bereich kleiner plastischer Dehnungen aus. Zusammen mit niedrigen Werten der senkrechten Anisotropie, die ein bevorzugtes Fließen aus der Dicke kennzeichnen, sind Preßteile mit hohem Streckziehanteil, z.B. Automobilaußenhautteile, der ideale Anwendungsbereich. Die starke Verfestigung dieses Werkstoffes, die schon bei kleinen plastischen Verformungen auftritt und sich in sehr hohen Workhardening-Werten äußert, ist ein wesentlicher Punkt für die Eigenschaften des Produktes. Die starke Verfestigung begünstigt die Kraftübertragung auf benachbarte Werkstoffbereiche, wodurch ein lokales frühzeitiges Materialversagen, z.B. Einschnürung, vermieden wird. Der Werkstoff kann somit über die gesamte Preßteilfläche gleichmäßiger fließen. Zusätzlich wirken sich die geringen Unterschiede der r-Werte in Abhängigkeit vom Winkel zur Walzrichtung günstig für ein gleichmäßiges Umformverhalten aus. Dieses isotrope Verhalten wird durch kleine Werte der planaren Anisotropie belegt.The steel strips or sheets produced by the process according to the invention are distinguished by an initial yield point (greater than 240 N / mm 2 ) which is favorable with regard to the subsequent deformation and a high strengthening capacity in the range of small plastic expansions. Together with low values of the vertical anisotropy, which characterize a preferred flow from the thickness, pressed parts with a high stretch-drawing proportion, for example automobile outer skin parts, are the ideal area of application. The strong solidification of this material, which occurs even with small plastic deformations and is expressed in very high work hardening values, is an essential point for the properties of the product. The strong solidification favors the transmission of force to neighboring material areas, which prevents local premature material failure, eg constriction. The material can therefore flow more evenly over the entire surface of the pressed part. In addition, the small differences in the r values depending on the angle to the rolling direction have a favorable effect on uniform forming behavior. This isotropic behavior is evidenced by small values of the planar anisotropy.

    BeispieleExamples

    Die über Strangguß hergestellten Brammen der erfindungsgemäß hergestellten Stähle A und B, deren chemische Zusammensetzungen in Tabelle 1 aufgeführt sind, wurden in einem Stoßofen auf Temperaturen von ca. 1200 °C wiedererwärmt und auf Enddicken von 2,8 - 3,3 mm oberhalb derThe slabs produced by continuous casting according to the invention manufactured steels A and B, their chemical Compositions listed in Table 1 were found in reheated in a pusher furnace to temperatures of approx. 1200 ° C and to final thicknesses of 2.8 - 3.3 mm above the

    Ar3-Temperatur warmgewalzt. Die Endwalz- und Haspeltemperaturen sind Tabelle 2 zu entnehmen. Für die Bänder der Stähle A und B wurden zwei Haspeltemperaturklassen angewendet: 730 °C (Stähle A1 und B1) und 600°C (Stähle A2 und B2). Die Bänder wurden mit Verformungsgraden zwischen 65 und 75 % auf Dicken zwischen 0,8 und 1,0 mm kaltgewalzt und anschließend in einer Feuerbeschichtungsanlage erst rekristallisierend geglüht und danach feuerverzinkt. Die Bandtemperatur im Rekristallisationsofen betrug 800 °C. Die Abkühlgeschwindigkeiten nach dem rekristallisierenden Glühen lagen zwischen 10 und 50 K/s. Die verzinkten Bänder wurden mit 1,8 % dressiert und waren danach streckgrenzendehnungsfrei.Ar 3 temperature hot rolled. The finish rolling and reel temperatures are shown in Table 2. Two reel temperature classes were used for the strips of steels A and B: 730 ° C (steels A1 and B1) and 600 ° C (steels A2 and B2). The strips were cold-rolled with degrees of deformation between 65 and 75% to thicknesses between 0.8 and 1.0 mm and then first recrystallized in a hot-dip coating plant and then hot-dip galvanized. The strip temperature in the recrystallization furnace was 800 ° C. The cooling rates after the recrystallizing annealing were between 10 and 50 K / s. The galvanized belts were treated with 1.8% and were then free from elongation limit.

    Tabellen 2 und 3 zeigen die im Zugversuch ermittelten mechanischen Eigenschaften und Korngrößen der Bänder A und B im Winkel von 90° zur Walzrichtung gemessen. Nur die r-Werte und die Werte für die planare Anisotropie berechnen sich wie folgt jeweils aus drei Zugproben, die in den Winkellagen 0°, 45° und 90° zur Walzrichtung entnommen wurden rm = (r0° + 2 r45° + r90°) / 4 , Δr = (r0° - 2 r45° + r90° ) / 2. Tables 2 and 3 show the mechanical properties and grain sizes of strips A and B determined in the tensile test measured at an angle of 90 ° to the rolling direction. Only the r values and the values for the planar anisotropy are calculated as follows from three tensile specimens, which were taken in the angular positions 0 °, 45 ° and 90 ° to the rolling direction r m = (r 0 ° + 2 r 45 ° + r 90 ° ) / 4, Δr = (r 0 ° - 2 r 45 ° + r 90 ° ) / 2.

    Der BH0-Wert entspricht dem Anstieg der unteren Streckgrenze nach einer Wärmebehandlung von 20 Minuten bei 170 °C. Die Größe WH gibt die Höhe der Verformungsverfestigung bei einer Reckung der Zugprobe um 2 % an. Sie wird berechnet, indem die Streckgrenze Rp0.2 von der gemessenen Spannung bei 2 % Verformung subtrahiert wird. Die Größe BH2 entspricht dem Anstieg der unteren Streckgrenze nach einer Wärmebehandlung von 20 Minuten bei 170 °C, gemessen an der 2 % vorgereckten Zugprobe.The BH 0 value corresponds to the increase in the lower yield strength after a heat treatment of 20 minutes at 170 ° C. The size WH indicates the amount of deformation hardening when the tensile test is stretched by 2%. It is calculated by subtracting the yield strength Rp 0.2 from the measured stress at 2% deformation. The size BH 2 corresponds to the increase in the lower yield strength after a heat treatment of 20 minutes at 170 ° C, measured on the 2% pre-stretched tensile test.

    Die feuerverzinkten kaltgewalzten Bänder aus den Stählen A und B zeigen nach einer künstlichen Alterung von 60 Minuten bei 100 °C ein nahezu unverändertes Niveau der unteren oder oberen Streckgrenze (Tabelle 3). Auch die Ausprägung der Streckgrenzendehnung bleibt unter 0,5 %, wodurch die Alterungsbeständigkeit für eine fließfigurenfreie Verarbeitung auch nach längeren Lagerzeiten ausreichend ist. Der Verlauf des differentiellen (momentanen) Verfestigungsexponentes (n-Wert) über der Gesamtdehnung ist in Fig. 1 für den Stahl A1 (Haspeltemperatur 730 °C) und in Fig. 2 für den Stahl A2 (Haspeltemperatur 600 °C) aufgetragen. Die Maxima der differentiellen n-Werte sind in Tabelle 2 jeweils aufgeführt; sie erreichen bei den Stählen A und B für beide Haspeltemperaturklassen mindestens 0,170, bei den hohen Haspeltemperaturen sogar mindestens 0,180. Das n-Wert-Maximum der Stähle A und B liegt im Bereich geringer Gesamtdehnungen zwischen 2 und 5 %. Die Streckgrenzen sind für die höhergehaspelten Varianten A1 und B1 ca. 50 N/mm2 größer als für die niedrig gehaspelten Varianten A2 und B2, so daß durch die Wahl der Haspeltemperatur die Ausgangslage der Streckgrenze festgelegt werden kann. Die Werte für die mittlere senkrechte Anisotropie sind für die erfindungsgemäßen Stähle A1, A2, B1 und B2 mit 1,0-1,1 gering. Unabhängig von der Haspeltemperatur besitzen sie isotrope Eigenschaften mit Δr-Werten zwischen 0 und 0,3. Bei Anwendung der hohen Haspeltemperaturen liegen die Work-hardening Werte, die ein Maß für die Verfestigung durch plastische Verformung darstellen, mit ca. 50 N/mm2 sehr hoch. Unabhängig von der Haspeltemperatur erreichen die Kenngrößen für das Bake-hardening mit oder ohne Vorverformung in allen Fällen mindestens 45 N/mm2. Der Streckgrenzenanstieg nach der Lackierbehandlung eines gepreßten Teiles kann durch die Summe WH+BH2 abgeschätzt werden. Bei den hohen Haspeltemperaturen (Stähle A1 und B1) liegen diese Werte mindestens bei 100 N/mm2. Bei den niedrigeren Haspeltemperaturen (Stähle A2 und B2) ist die Summe WH+BH2 mit mindestens 60 N/mm2 immer noch günstig.The hot-dip galvanized cold-rolled strips made of steels A and B show an almost unchanged level of the lower or upper yield strength after artificial aging of 60 minutes at 100 ° C (Table 3). The extent of the yield point elongation also remains below 0.5%, which means that the aging resistance is sufficient for processing without flow figures even after long periods of storage. The course of the differential (instantaneous) hardening exponent (n value) over the total strain is plotted in FIG. 1 for steel A1 (reel temperature 730 ° C.) and in FIG. 2 for steel A2 (reel temperature 600 ° C.). The maxima of the differential n values are listed in Table 2; For steels A and B, they reach at least 0.170 for both reel temperature classes, and at least 0.180 for high reel temperatures. The n value maximum of steels A and B is in the range of low total strains between 2 and 5%. The yield strengths are approximately 50 N / mm 2 larger for the higher-coiled variants A1 and B1 than for the low-coiled variants A2 and B2, so that the starting position of the yield strength can be determined by the choice of the coiling temperature. The values for the mean vertical anisotropy for the steels A1, A2, B1 and B2 according to the invention are low at 1.0-1.1. Regardless of the reel temperature, they have isotropic properties with Δr values between 0 and 0.3. When using the high reel temperatures, the work-hardening values, which are a measure of the hardening by plastic deformation, are very high at approx. 50 N / mm 2 . Regardless of the reel temperature, the parameters for bake hardening with or without pre-deformation in all cases reach at least 45 N / mm 2 . The increase in yield strength after the painting treatment of a pressed part can be estimated by the sum WH + BH 2 . At high reel temperatures (steels A1 and B1) these values are at least 100 N / mm 2 . At the lower reel temperatures (steels A2 and B2) the sum WH + BH 2 with at least 60 N / mm 2 is still cheap.

    In den Tabellen 1, 2 und 3 sind zusätzlich Stähle C bis E zum Vergleich aufgeführt, die im Unterschied zu den Stählen A und B entweder kein Titan enthalten (Stahl E) oder Titangehalte besitzen, die bezogen auf den Stickstoffgehalt unterstöchiometrisch liegen (Stähle C und D mit Ti/N < 3.4). Die Werte des Ausgangszustandes, d.h. nicht gealtert, beziehen sich auf den ausdressierten Zustand. Der Anstieg der unteren Streckgrenze (Re1) und der Streckgrenzendehnungen nach einer künstlichen Alterung sind bei diesen Vergleichsstählen deutlich höher als bei den erfindungsgemäß hergestellten Stählen A und B. Vor allem die obere Streckgrenze (Reh) nimmt bis zuTables 1, 2 and 3 also list steels C to E for comparison, which, in contrast to steels A and B, either contain no titanium (steel E) or have titanium contents that are substoichiometric in relation to the nitrogen content (steels C and D with Ti / N <3.4). The values of the initial state, ie not aged, refer to the extracted state. The increase in the lower yield strength (R e1 ) and the yield strength expansions after artificial aging are significantly higher in these comparative steels than in the steels A and B produced according to the invention. In particular, the upper yield strength (deer) increases

    70 N/mm2 zu. Eine fehlerfreie Verarbeitung nach längerer Auslagerung ist bei den Stählen C bis E nicht möglich.70 N / mm 2 too. Error-free processing after long outsourcing is not possible with steels C to E.

    Das Umformverhalten der erfindungsgemäß hergestellten Stähle A1 und B1 wurde in einem praxisnahen Großversuch anhand von formgepreßten PKW-Motorhauben umfangreich untersucht. Es wurden bezüglich Formtreue und Oberfläche der Preßteile einwandfreie Abpreßergebnisse erzielt, die auch bei der Verarbeitung nach einer Lagerzeit von 5 Monaten reproduzierbar waren. Stahl C Mn Si P S Al N Ti Nb Ti/N A 0.042 0.24 0.01 0.009 0.005 0.037 0.0028 0.016 - 5.7 B 0.041 0.24 0.05 0.009 .0.005 0.042 0.0025 0.015 - 6.0 C 0.050 0.25 0.01 0.009 0.010 0.030 0.0042 0.009 - 2.1 D 0.044 0.26 0.01 0.011 0.007 0.036 0.0034 0.009 - 2.6 E 0.031 0.23 0.01 0.010 0.011 0.039 0.0045 - - - Stahl Endwalztemperatur (°C) Haspeltemperatur (°C) Kallwalzgrad (%) Kallbanddicke (mm) Rpo2 (N/mm2) Rm (N/mm7) A (%) mittlerer r-Wert Δ r Korngröße in µm2 A1 910 730 70 1.0 262 375 33 1.1 0.25 180 A2 870 600 70 1.0 315 390 35 1.0 0.18 130 B1 900 730 73 0.8 265 375 31 1.0 0.28 170 B2 870 600 70 1.0 318 305 34 1.1 0.15 130 C 870 570 61 1.5 285 373 33 D 880 600 65 1.0 298 390 33 E 900 760 68 0.9 232 365 32 250

    Figure 00150001
    The forming behavior of the steels A1 and B1 produced according to the invention was extensively investigated in a practical large-scale test using molded car bonnets. Flawless pressing results were achieved with respect to the shape and surface of the pressed parts, which were reproducible even after processing after a storage period of 5 months. steel C Mn Si P S al N Ti Nb Ti / N A 0042 00:24 00:01 0009 0005 0037 0.0028 0016 - 5.7 B 0041 00:24 00:05 0009 .0.005 0042 0.0025 0015 - 6.0 C 0050 00:25 00:01 0009 0010 0030 0.0042 0009 - 2.1 D 0044 00:26 00:01 0011 0007 0036 0.0034 0009 - 2.6 e 0031 00:23 00:01 0010 0011 0039 0.0045 - - - steel Finish rolling temperature (° C) Reel temperature (° C) Kallwalzgrad (%) Tape thickness (mm) R po2 (N / mm 2 ) Rm (N / mm 7 ) A (%) mean r-value Δ r Grain size in µm 2 A1 910 730 70 1.0 262 375 33 1.1 00:25 180 A2 870 600 70 1.0 315 390 35 1.0 00:18 130 B1 900 730 73 0.8 265 375 31 1.0 00:28 170 B2 870 600 70 1.0 318 305 34 1.1 00:15 130 C 870 570 61 1.5 285 373 33 D 880 600 65 1.0 298 390 33 e 900 760 68 0.9 232 365 32 250
    Figure 00150001

    Claims (5)

    1. Method for producing a cold-rolled steel sheet or strip having good formability, in particular stretch formability for making pressings with high buckling resistance from a steel comprising (in % by mass):
      C: 0.01 - 0.08%
      Mn: 0.10 - 0.80%
      Si: maximum of 0.60%
      Al: 0.015 - 0.08%
      N: maximum of 0.005%
      Ti: 0.01 - 0. 04 %, whose content exceeding the quantity necessary for stoichiometric binding of nitrogen ranges from 0.003 to 0.015 % Ti, and a maximum 0.15 % in total of one or several elements from the group copper, vanadium, nickel, the remainder being iron and unavoidable impurities, including a maximum of 0.08 % P and a maximum 0.02 % S,
      consisting of preheating the cast slab to a temperature exceeding 1050° C,
      hot-rolling at a final temperature ranging from over the Ar3 temperature to 950° C,
      coiling the hot-rolled strip at a temperature ranging from 550 to 750° C
      cold-rolling with a total degree of deformation from 40 to 85 %,
      recrystallisation annealing of the cold strip in a continuous furnace at a temperature of at least 720° C,
      cooling at cooling rates of 5 to 70 K/s and
      final skin-passing.
    2. Method according to Claim 1, characterised in that the cold rolled strip is heated to the temperature of recrystallisation annealing at a rate ranging from 5 to 10 K/s.
    3. Method according to Claims 1 or 2, characterised in that the recrystallisation annealing of the cold-rolled strip takes place in-line in a zinc hot-dip galvanizing plant.
    4. Method according to Claim 3, characterised in that the silicon content is limited to a maximum of 0.15 %.
    5. Method according to Claim 1, characterised in that the final rolling takes place at a temperature ranging from 870 to 950° C.
    EP97922915A 1996-06-01 1997-04-26 Process for producing an easily shaped cold-rolled sheet or strip Expired - Lifetime EP0914480B1 (en)

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    DE19740148C1 (en) * 1997-09-12 1999-07-15 Thyssenkrupp Stahl Ag Process for the manufacture of dent-resistant enamelled components made of age-sensitive steel
    FR2795740B1 (en) * 1999-07-01 2001-08-03 Lorraine Laminage CALM LOW-CARBON STEEL SHEET WITH ALUMINUM FOR PACKAGING
    FR2795742B1 (en) * 1999-07-01 2001-08-03 Lorraine Laminage CALM ALUMINUM CARBON STEEL SHEET FOR PACKAGING
    FR2795743B1 (en) 1999-07-01 2001-08-03 Lorraine Laminage LOW ALUMINUM STEEL SHEET FOR PACKAGING
    FR2795741B1 (en) * 1999-07-01 2001-08-03 Lorraine Laminage CALM LOW-CARBON STEEL SHEET WITH ALUMINUM FOR PACKAGING
    DE10020118B4 (en) * 2000-04-22 2009-11-12 Schaeffler Kg Method for verifying sealability of selected exhaust valve of selected cylinder in internal combustion engine in motor vehicle, involves concluding sealability of valve based on measured values of lambda sensor in one of exhaust gas strands
    DE10102932C1 (en) * 2001-01-23 2002-08-22 Salzgitter Ag Process for producing a cold-rolled steel strip or sheet and strip or sheet which can be produced by the process
    FR2820150B1 (en) * 2001-01-26 2003-03-28 Usinor HIGH STRENGTH ISOTROPIC STEEL, METHOD FOR MANUFACTURING SHEETS AND SHEETS OBTAINED
    US6635127B2 (en) * 2001-08-02 2003-10-21 Illinois Tool Works Inc. Steel strapping and method of making
    SE526120C2 (en) 2002-03-13 2005-07-05 Avestapolarit Ab Process for the manufacture of an ultra-high-strength stretched or stretched product of steel
    FR2845694B1 (en) * 2002-10-14 2005-12-30 Usinor METHOD FOR MANUFACTURING COOK-CURABLE STEEL SHEETS, STEEL SHEETS AND PIECES THUS OBTAINED
    KR20060028909A (en) * 2004-09-30 2006-04-04 주식회사 포스코 High strength cold rolled steel sheet excellent in shape freezability,and manufacturing method thereof
    DE102005058658A1 (en) * 2005-12-07 2007-06-14 Kermi Gmbh Method for reducing the wall thickness of steel radiators
    CN103108964B (en) 2010-08-31 2015-06-17 塔塔钢铁艾默伊登有限责任公司 Method for hot forming a coated metal part and formed part
    UA109963C2 (en) * 2011-09-06 2015-10-26 CATHANE STEEL, APPROVING CONSEQUENCES OF SEPARATION OF PARTS AFTER HOT FORMING AND / OR CUTTING IN TOOL, THAT HAS A HIGHER MACHINE
    JP5618431B2 (en) 2013-01-31 2014-11-05 日新製鋼株式会社 Cold rolled steel sheet and method for producing the same
    US20140261903A1 (en) * 2013-03-15 2014-09-18 Am/Ns Calvert Llc High strength bake hardenable low alloy steel and process for manufacture thereof
    CN103276172B (en) * 2013-05-14 2015-01-21 武汉钢铁(集团)公司 Energy-saving rolling method of low alloy steel based on critical temperature
    JP6636512B2 (en) * 2014-10-09 2020-01-29 ティッセンクルップ スチール ヨーロッパ アクチェンゲゼルシャフトＴｈｙｓｓｅｎＫｒｕｐｐ Ｓｔｅｅｌ Ｅｕｒｏｐｅ ＡＧ Cold rolled and recrystallized annealed flat steel products and methods for producing the same
    BR112019002875B1 (en) 2016-09-20 2022-11-22 Thyssenkrupp Steel Europe Ag METHOD FOR MANUFACTURING FLAT STEEL PRODUCTS AND FLAT STEEL PRODUCTS
    CN112131528B (en) * 2020-09-10 2023-08-04 东北大学 Tension distribution setting method for asynchronous cold continuous rolling process of steel strip
    CN112853212B (en) * 2021-01-05 2022-06-07 广西柳钢华创科技研发有限公司 Low-cost cold-rolled high-strength steel for tool cabinets

    Family Cites Families (4)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    JPS5246323A (en) * 1975-10-10 1977-04-13 Nisshin Steel Co Ltd Process for producing cold rolled high tensile strength steel plate ha ving excellent flange pressed drawability
    DE3803064C2 (en) * 1988-01-29 1995-04-20 Preussag Stahl Ag Cold rolled sheet or strip and process for its manufacture
    WO1994005823A1 (en) * 1992-08-31 1994-03-17 Nippon Steel Corporation Cold-rolled sheet and hot-galvanized, cold-rolled sheet, both excellent in bake hardening, cold nonaging and forming properties, and process for producing the same
    DE19547181C1 (en) * 1995-12-16 1996-10-10 Krupp Ag Hoesch Krupp Mfg. cold-rolled, high strength steel strip with good shapability

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