EP2045360B1 - Method for manufacturing a steel part by hot forming and steel part manufactured by hot forming - Google Patents

Method for manufacturing a steel part by hot forming and steel part manufactured by hot forming Download PDF

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Publication number
EP2045360B1
EP2045360B1 EP07117719A EP07117719A EP2045360B1 EP 2045360 B1 EP2045360 B1 EP 2045360B1 EP 07117719 A EP07117719 A EP 07117719A EP 07117719 A EP07117719 A EP 07117719A EP 2045360 B1 EP2045360 B1 EP 2045360B1
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EP
European Patent Office
Prior art keywords
coating
steel
hot
flat product
base layer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Revoked
Application number
EP07117719A
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German (de)
French (fr)
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EP2045360A1 (en
Inventor
Sabine Hasenfuss
Barbara Lupp
Ansgar Albers
Manfred Meurer
Wilhelm Warnecke
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ThyssenKrupp Steel Europe AG
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ThyssenKrupp Steel Europe AG
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Application filed by ThyssenKrupp Steel Europe AG filed Critical ThyssenKrupp Steel Europe AG
Priority to EP07117719A priority Critical patent/EP2045360B1/en
Priority to AT07117719T priority patent/ATE535631T1/en
Priority to US12/681,286 priority patent/US20100294400A1/en
Priority to PCT/EP2008/063139 priority patent/WO2009047183A1/en
Publication of EP2045360A1 publication Critical patent/EP2045360A1/en
Application granted granted Critical
Publication of EP2045360B1 publication Critical patent/EP2045360B1/en
Revoked legal-status Critical Current
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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
    • C21D7/00—Modifying the physical properties of iron or steel by deformation
    • C21D7/02—Modifying the physical properties of iron or steel by deformation by cold working
    • 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
    • C21D8/0278—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips involving a particular surface treatment
    • 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
    • C21D9/48—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals deep-drawing sheets
    • 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
    • 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
    • C23C2/024—Pretreatment of the material to be coated, e.g. for coating on selected surface areas by cleaning or etching
    • 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
    • C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/06—Zinc or cadmium or alloys based thereon
    • 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
    • C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/12—Aluminium or alloys based thereon

Definitions

  • the invention relates to a method for producing a steel component provided with a metallic coating which protects against corrosion, in particular by a cathodic protective effect, by thermoforming a flat steel product produced from a low-alloy tempered steel. Moreover, the invention relates to a steel component produced by thermoforming a flat steel product and provided with a corrosion protection coating which protects against corrosion, in particular by a cathodic protective action.
  • a process that allows the production of correspondingly high-strength and at the same time thin-walled steel components is hot-press hardening.
  • hot press hardening a circuit board is first cut from a steel strip. This board is then heated to a thermoforming temperature that is typically above the Ar3 temperature of the particular steel material being processed. The thus heated board is then placed in a hot state in a forming tool and placed in the desired component shape. Subsequently, or meanwhile, there is a cooling of the molded component, in which a hardened or hardened structure is produced in the processed steel.
  • the thus composed steel strip is according to the EP 0 971 044 B1 provided with a coating based on aluminum or an aluminum alloy.
  • this coating is an AlSi coating which has Fe contents.
  • the thus coated steel strip is heated to a temperature of more than 750 ° C, formed into a component and then cooled at a cooling rate, under which forms a hardness structure.
  • the object of the invention was to provide an economical process for the production of high-strength steel components, which have optimized corrosion protection and are particularly suitable for use in automobile bodies.
  • a suitably procured steel component should be created.
  • a metallic coating is produced on a flat steel product produced from a low-alloy tempered steel, which consists of two successively applied in two process steps Layers is formed.
  • the tempering steel may be, for example, a Mn-B steel, as it is already widely used in the prior art.
  • the flat steel product produced from the suitably composed tempering steel is provided with an Al coating containing at least 85% by weight of Al, with additional contents of up to 15% by weight of Si in the Al coating applied according to the invention available.
  • Typical variants of the Al coating applied according to the invention are a coating consisting almost entirely of Al or an AlSi variant in which the Si content of the applied AlSi coating is 8-12% by weight Si.
  • a Zn coating is applied to this Al-coating, which consists of at least 90 wt .-% of zinc.
  • the two-layered coated flat steel product is then heated to at least 750 ° C hot forming temperature. This results in the formation of an alloyed Al, Fe, Zn and Si base layer in which Al has the largest share, but Fe, Zn and Si emerge as essential ingredients.
  • thermoforming temperatures of 850 to 950 ° C., in particular 850 to 900 ° C., are typically set according to the invention.
  • the heated to the hot forming temperature flat steel product is thermoformed in a further step in a conventional manner to the respective component and in one accelerated for the desired training of the tempering or hardening structure accelerated.
  • the heating to the thermoforming temperature can be preceded by a division of the flat product, which has previously been present as a strip in the manner according to the invention in two layers, into sheets.
  • each of the individual coating steps may be preceded by a cleaning of the surface of the flat steel product or the coating applied thereto.
  • coated flat steel product proved both for a direct, d. h as a one-step work step without previous cold forming performed thermoforming, as well as for an indirect, d. H. at least two-stage shaping characterized by a succession of cold working and hot working.
  • a steel component obtained in accordance with the invention bears a metallic coating which is formed by a base layer resting on the flat steel product and a cover layer lying on the base layer, the base layer containing at least 30% by weight Al, at least 20% by weight. % Fe and at least 3 wt .-% Si and the top layer at least 60 wt .-% Zn, in particular at least 80 wt .-%, and at least 5 wt .-% Al and up to 10 wt .-% Fe and up to 10 wt .-% Si has.
  • the Zn coating is deposited electrolytically on the Al coating as an alternative to hot-dip galvanizing.
  • electrolytic galvanizing is preferably a layer with a Zn content of at least 99 wt .-% deposited.
  • Another alternative way of applying the Zn layer is to deposit the Zn coating on the Al coating in a PVD process.
  • PVD Physical Vapor Deposition
  • At least one other element of Al, Mg or Fe may be included.
  • the contents should not exceed 5% by weight Al, 5% by weight Mg and / or 0.5% by weight Si.
  • the contents of other accompanying elements in the Zn coating should not exceed 1 wt .-% in total.
  • the flat products coated according to the invention are passed through an acid bath which rinses the oxide layer off them, without attacking the surface of the flat steel product itself.
  • the Oxidabtrag is controlled so that you get a favorable set for the electrolytic strip galvanizing surface.
  • the process according to the invention can be carried out in a particularly economical manner when the Al coating and then the Zn coating and all the work steps required between the respective coating steps are completed in a sequence of operations continuously following each other.
  • coated steel strip according to the invention proves to be particularly insensitive to those in hot forming in one Traces occurring even if the respective component receives a complex shape.
  • a base layer which is directly on the flat steel product and consists predominantly of Al and additional Fe, Zn and Si contents, on which predominantly Zn and additional contents are present Al, Si and Fe existing cover layer is located.
  • the base layer has at least 30 wt .-% Al, at least 20 wt .-% Fe, at least 3 wt .-% Si and at most 30 wt .-% Zn, while in the top layer at least 60 wt .-%, in particular at least 80 wt .-%, Zn at least 5 wt .-% Al and at most 10 wt .-% Fe and at most 10 wt .-% Si are present.
  • the thickness of the base layer of the finished molded component according to the invention is typically 10 to 50 ⁇ m, in particular 15 to 25 ⁇ m, while the thickness of the cover layer is typically in the range of 5 to 20 ⁇ m, in particular 3 to 10 ⁇ m.
  • Fig. 2 shows an example where the in Fig. 1 are passed through specified work steps, but not in a continuous, but in a broken sequence. So is in the in Fig. 2 Example given after the passing of the previously hot-rolled steel strip, the strip wound into a coil, brought to an electrolytic coating device, cleaned there and dekapiert and then provided electrolytically with the applied to the AlSi coating Zn coating.
  • Fig. 5 there is an example of a procedure in which the steel strip is first cleaned, then fire-aluminized (ie annealed and passed through an AlSi melt bath), then finish rolled, then cleaned, and finally by using a PVD method the Zn layer is coated.
  • Fig. 6 shows in its left half the layer structure of a coating, as it is present in the inventive procedure before heating to thermoforming temperature. Accordingly, an alloy layer containing Al, Si and Fe is formed between the steel substrate and the overlying AlSi layer containing typically 90 wt% and 10 wt% Si.
  • the AlSi layer (“first layer”) and the alloy layer together form the "base layer” of the overall coating.
  • the Zn layer (“second layer”) which typically consists of 99% by weight of Zn and less than 1% by weight of Al, is applied to the "base layer" as the "top layer".
  • Fig. 6 shows the layer structure of the overall coating, which is at a temperature of more than five minutes extending heating of the layer structure shown in the left half of 900 ° C.
  • a base layer consisting of 40% by weight of Al, 30% by weight of Fe, 20% by weight of Zn and 5% by weight of Si, on which a covering layer consisting of 80% by weight of Zn, 16% by weight of Al, 2% by weight of Si and 2% by weight of Fe.
  • Cover layer and base layer together form the total coating there as well.
  • a steel strip made of a hardenable steel having a carbon content of 0.22%, a Mn content of 1.2%, a Cr content of 0.20% and a B content of 0.003% is referred to as a cold-rolled strip in annealed in a continuous hot dip coating line and coated with an AlSi melt.
  • the tape was first cleaned in a cleaning part of the debris from the cold rolling process and then went through an annealing furnace by being heated to 750 ° C.
  • the strip has been recrystallized in the annealing furnace in a protective gas atmosphere with 10% H 2 and balance N 2 recrystallizing.
  • the surface roughness of the strip provided with the AlSi coating is adjusted by temper rolling in a skin pass mill.
  • the strip was then first chemically treated in an aqueous solution with 80 g / l HCl (hydrochloric acid) for 10 s at 40 ° C.
  • Fig. 9 is shown for the existing on the thus produced component total coating.
  • a steel strip of a hardenable steel is as a cold-rolled strip in a continuous Hot dip coating line annealed and coated.
  • the tape has first been cleaned and annealed as in Example 1. Subsequently, it has undergone an aluminum-silicon bath (Si content 10%) whose temperature was 660 ° C. The thickness of the resulting AlSi coating then adjusted by means of wiping nozzles was 15 ⁇ m. After a cooling section, over which the tape has been cooled to 480 ° C, the tape is immersed in a second molten bath of zinc, which was provided with an addition of 0.2% Al. With the subsequent wiping a zinc coating thickness of 5 microns has been set. After cooling the strip to ⁇ 50 ° C, the setting of the surface roughness was carried out in a skin pass mill. Finally, the tape has been wound into a finished coil.
  • a steel strip of a hardenable steel has been annealed and coated as a cold rolled strip in a continuous hot dip coating line.
  • the tape is first cleaned as in Example 1, annealed and provided with an AlSi coating.
  • the coating thickness set by the wiping nozzles is in this case 20 ⁇ m. After cooling the strip to ⁇ 50 ° C, the surface roughness was adjusted by temper rolling in a skin pass mill.
  • the strip was first cleaned alkaline, then to be coated in a PVD module with a zinc coating of 3 microns. Finally, the tape has been wound into a finished coil.
  • Blanks were cut from the coated strip for the hot forming process and heated in an oven at 900 ° C for 5 min. Subsequently, the boards are transferred by manipulator in a forming press and here converted into a component and cooled in the tool accelerated.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Other Surface Treatments For Metallic Materials (AREA)
  • Coating With Molten Metal (AREA)
  • Physical Vapour Deposition (AREA)

Abstract

A low-alloy, sheet steel which can be hardened, is coated with metal containing at least 85 wt% aluminum and up to 15 wt% Si. A zinc coating is then added, containing at least 90 wt% Zn. The material is heated to at least 750[deg] C prior to thermal deformation. The flat product is then thermo-formed to make the steel component. To produce the hardened structure, it is cooled at a sufficiently rapid rate. The hot deformation temperature is preferably 850-900[deg] C. The aluminum coating is added by hot dip aluminization. It contains 5-12 wt% silicon. The zinc is coated onto the aluminum layer electrolytically. It contains at least 99 wt% Zn. It is alternatively coated by physical vapor deposition. In the zinc coating, one or more of Al, Mg and Si are contained. Before zinc coating, the aluminum-coated steel is given a rolled finish. It is pickled before zinc coating. Both coatings take pace continuously, in successive processes. Alternatively, successive batch processes are used. Hot deformation takes place in one or more stages. This is optionally preceded by cold deformation. Before heating, the aluminum coating has a thickness of 5-25 mu m. Before heating, a 2-5 mu m thick alloying boundary layer containing Al, Si and Fe is provided between the steel and the aluminum. The total thickness of the coating on the steel before heating, is 7-35 mu m. The base layer coating on the steel is predominantly aluminum, containing Fe, Zn and Si. This is coated with a layer of metal predominantly comprising zinc, which contains Al, Si and Fe. The base layer contains at least: 30 wt% Al, 20 wt% Fe and 3 wt% Si. The outer covering layer contains at least: 60 wt% Zn, 5 wt% Al. It also includes up to: 10 wt% Fe and 10 wt% Si. The base layer thickness is 15-25 mu m. The covering layer thickness is 3-10 mu m. The sheet steel product is produced from manganese-boron steel. An independent claim IS INCLUDED FOR the corresponding steel component.

Description

Die Erfindung betrifft ein Verfahren zum Herstellen eines mit einer metallischen, vor Korrosion, insbesondere durch eine kathodische Schutzwirkung, schützenden Überzug versehenen Stahlbauteils durch Warmformen eines aus einem niedrig legierten Vergütungsstahl erzeugten Stahlflachprodukts. Darüber hinaus betrifft die Erfindung ein durch Warmformen eines Stahlflachproduktes erzeugtes, mit einer metallischen, vor Korrosion, insbesondere durch eine kathodische Schutzwirkung, schützenden Korrosionsschutzbeschichtung versehenes Stahlbauteil.The invention relates to a method for producing a steel component provided with a metallic coating which protects against corrosion, in particular by a cathodic protective effect, by thermoforming a flat steel product produced from a low-alloy tempered steel. Moreover, the invention relates to a steel component produced by thermoforming a flat steel product and provided with a corrosion protection coating which protects against corrosion, in particular by a cathodic protective action.

Wenn hier von Stahlflachprodukten die Rede ist, so sind damit Stahlbänder, Stahlbleche oder daraus gewonnene Platinen sowie das Stahlsubstrat des aus solchen Bändern, Blechen oder Platinen gewonnenen Stahlbauteils gemeint.When it comes to flat-rolled steel products, it refers to steel strips, steel sheets or blanks obtained therefrom and the steel substrate of the steel component obtained from such strips, sheets or blanks.

An die Steifigkeit und Festigkeit von Bauteilen werden gerade im Fahrzeugbau zunehmend hohe Anforderungen gestellt. Gleichzeitig werden jedoch im Interesse einer Optimierung des für den Antrieb des jeweiligen Fahrzeugs benötigten Energieverbrauchs ein möglichst geringes Karosseriegewicht und entsprechend geringe Materialdicken angestrebt. Erfüllt werden können diese auf den ersten Blick widersprüchlichen Anforderungen durch hochfeste und höchstfeste Stahlwerkstoffe, welche unter Anwendung geeigneter Verfahrensschritte die Herstellung von Bauteilen mit sehr hoher Festigkeit bei geringer Materialdicke erlauben.The rigidity and strength of components are becoming increasingly demanding, especially in vehicle construction. At the same time, however, in the interest of optimizing the energy consumption required for the drive of the respective vehicle, it is desirable to have the lowest possible body weight and correspondingly low material thicknesses. These can be fulfilled at first View contradictory requirements by high-strength and ultra-high-strength steel materials, which allow the use of suitable process steps to produce components with very high strength and low material thickness.

Ein Verfahren, dass die Herstellung entsprechend hochfester und gleichzeitig dünnwandiger Stahlbauteile erlaubt, ist das Warmpresshärten. Beim Warmpresshärten wird zunächst aus einem Stahlband eine Platine geschnitten. Diese Platine wird dann auf eine Warmformtemperatur erwärmt, die in der Regel oberhalb der Ar3-Temperatur des jeweils verarbeiteten Stahlwerkstoffs liegt. Die so erwärmte Platine wird dann im warmen Zustand in ein Umformwerkzeug gelegt und darin in die gewünschte Bauteilform gebracht. Anschließend bzw. unterdessen erfolgt eine Abkühlung des geformten Bauteils, bei der im verarbeiteten Stahl ein Vergütungs- bzw. Härtegefüge entsteht.A process that allows the production of correspondingly high-strength and at the same time thin-walled steel components is hot-press hardening. In hot press hardening, a circuit board is first cut from a steel strip. This board is then heated to a thermoforming temperature that is typically above the Ar3 temperature of the particular steel material being processed. The thus heated board is then placed in a hot state in a forming tool and placed in the desired component shape. Subsequently, or meanwhile, there is a cooling of the molded component, in which a hardened or hardened structure is produced in the processed steel.

Für das Pressformhärten kommen niedrig legierte Stähle in Frage. Allerdings sind diese Stähle empfindlich gegen korrosive Angriffe, denen sie insbesondere dann ausgesetzt sind, wenn sie für den Bau von Fahrzeugkarosserien verwendet werden.For compression molding, low alloyed steels come into question. However, these steels are susceptible to corrosive attack which they are exposed to when used for the construction of vehicle bodies.

In jüngerer Zeit sind verschiedene Versuche gemacht worden, die Vorteile des Warmumformens von hochfesten, für das Warmpresshärten geeigneten Stählen gerade auch für diese Einsatzbereiche nutzbar machen. Als Vorreiter dieser Entwicklung ist der in der EP 0 971 044 B1 beschriebene Stand der Technik zu nennen. Gemäß diesem bekannten Verfahren wird ein warmgewalztes Stahlblech verarbeitet, welches neben Eisen und unvermeidbaren Verunreinigungen in (Gew.-%) zwischen 0,15 - 0,5 % C, zwischen 0,5 - 3 % Mn, zwischen 0,1 - 0,5 % Si, zwischen 0,01 - 1 % Cr, weniger als 0,2 % Ti, jeweils weniger als 0,1 % A1 und P, weniger als 0,05 S sowie zwischen 0,0005 - 0,08 % B enthält. Der entsprechend dieser Vorschrift zusammengesetzte Stahl ist in der Praxis unter der Bezeichnung 22MnB5 bekannt.More recently, various attempts have been made to harness the benefits of hot forming high strength steels suitable for hot press hardening, especially for these applications. As a pioneer of this development is in the EP 0 971 044 B1 To describe prior art described. According to this known processes, a hot rolled steel sheet is processed, which in addition to iron and unavoidable impurities in (wt .-%) between 0.15 - 0.5% C, between 0.5 - 3% Mn, between 0.1 - 0.5% Si, between 0.01-1% Cr, less than 0.2% Ti, less than 0.1% A1 and P, less than 0.05 S, and between 0.0005-0.08% B, respectively. The steel assembled in accordance with this requirement is known in practice as 22MnB5.

Das derart zusammengesetzte Stahlband wird gemäß der EP 0 971 044 B1 mit einer Beschichtung versehen, die auf Aluminium oder einer Aluminiumlegierung basiert. Insbesondere handelt es sich bei dieser Beschichtung um einen AlSi-Überzug, der Gehalte an Fe aufweist. Das derart beschichtete Stahlband wird auf eine Temperatur von mehr als 750 °C erwärmt, zu einem Bauteil geformt und anschließend mit einer Abkühlgeschwindigkeit abgekühlt, unter der sich ein Härtegefüge ausbildet.The thus composed steel strip is according to the EP 0 971 044 B1 provided with a coating based on aluminum or an aluminum alloy. In particular, this coating is an AlSi coating which has Fe contents. The thus coated steel strip is heated to a temperature of more than 750 ° C, formed into a component and then cooled at a cooling rate, under which forms a hardness structure.

Das in der aus der EP 0 971 044 B1 bekannten Weise erzeugte Stahlbauteil weist neben guten Festigkeitseigenschaften eine grundsätzlich gute Beständigkeit gegen Korrosion auf. Gleichzeitig lassen sich aus den gemäß diesem Stand der Technik zur Verfügung gestellten Stahlblechen in nur einem einzigen Warmumformschritt Stahlbauteile erzeugen, ohne dass es zu einer Beschädigung der Al-Beschichtung kommt.That in the from the EP 0 971 044 B1 known steel component produced in addition to good strength properties a basically good resistance to corrosion. At the same time, the steel sheets made available in accordance with this prior art can be used to produce steel components in just one hot stamping step, without the Al coating being damaged.

Den in der bekannten Weise verarbeiteten, mit einem Albasierten Überzug versehenen Stählen fehlt eine wesentliche Eigenschaft, die den Stahl bei Verletzung kathodisch gegen Korrosion schützt. Diese Empfindlichkeit erweist sich insbesondere beim Einsatz der nach dem bekannten Verfahren verarbeiteten Stähle im Bereich von Karosserie für Automobile als problematisch.The processed in the known manner, provided with an Albasierten coating steel is missing an essential property that the steel in case of injury cathodic protects against corrosion. This sensitivity is particularly problematic when using the steels processed by the known method in the field of bodywork for automobiles.

Um diesen Nachteil zu vermeiden, ist in der WO 2005/021820 A1 , der WO 2005/021821 A1 und der WO 2005/021822 A1 vorgeschlagen worden, anstelle eines Albasierten Überzugs eine auf Zink basierende Beschichtung auf das Stahlsubstrat aufzubringen. Aus derart beschichteten Stahlflachprodukten erzeugte Blechbauteile weisen zwar einen kathodischen Korrosionsschutz auf. Dazu muss allerdings in Kauf genommen werden, dass die Verformung des jeweiligen Stahlflachprodukts zu dem Bauteil in mindestens zwei Stufen erfolgen muss, wobei die erste Stufe eine Kaltverformung ist, in der der weitaus größte Teil der Formgebung erfolgt, und im Zuge der Warmverformungsstufe lediglich noch eine Kalibrierung des Bauteils mit anschließender Abschreckung möglich ist. Dies führt zu einer nur begrenzten wirtschaftlichen Nutzbarkeit dieses bekannten Prozesses.To avoid this disadvantage is in the WO 2005/021820 A1 , of the WO 2005/021821 A1 and the WO 2005/021822 A1 It has been proposed to apply a zinc-based coating to the steel substrate instead of an albuminated coating. Although sheet metal components produced from such coated flat steel products have cathodic corrosion protection. It must be accepted, however, that the deformation of the respective flat steel product to the component must be carried out in at least two stages, the first stage is a cold deformation, in which by far the largest part of the shaping takes place, and in the course of the hot deformation stage only one Calibration of the component with subsequent deterrence is possible. This leads to a limited economic usability of this known process.

Ein alternativer Versuch, aus Stählen der in der EP 0 971 044 B1 beschriebenen Art erzeugte Bauteile effektiver für den Einsatz im Fahrzeugkarosseriebau verwenden zu können, ist aus der DE 103 33 166 A1 beschrieben. Gemäß dem aus dieser Offenlegungsschrift bekannten Verfahren wird ein Stahlbauteil in einer aus der EP 0 971 044 B1 bekannten Weise erzeugt und anschließend mit einer zusätzlichen Zinkschicht überzogen. Durch diese nachträgliche Stückverzinkung ist zwar das Problem des kathodischen Korrosionsschutzes gelöst, jedoch muss dazu ein zusätzlicher nachträglicher Beschichtungsschritt in Kauf genommen werden, der nicht nur zu einem erhöhten Zeitaufwand bei der Herstellung von Karosseriebauteilen, sondern auch zu einem erhöhten Kostenaufwand führt.An alternative experiment, made of steels in the EP 0 971 044 B1 described to be able to use components produced more effectively for use in vehicle body construction, is from the DE 103 33 166 A1 described. According to the method known from this publication, a steel component in one of the EP 0 971 044 B1 produced manner known and then coated with an additional zinc layer. By this subsequent piece galvanizing is indeed the problem of cathodic corrosion protection solved, however, must be taken to an additional subsequent coating step in purchasing, which not only leads to an increased expenditure of time in the manufacture of body parts, but also at an increased cost.

Vor dem Hintergrund des voranstehend erläuterten Standes der Technik lag der Erfindung die Aufgabe zugrunde, ein wirtschaftliches Verfahren zur Herstellung von hochfesten Stahlbauteilen anzugeben, die einen optimierten Korrosionsschutz besitzen und insbesondere für den Einsatz in Automobilkarosserien geeignet sind. Darüber hinaus sollte ein entsprechend beschaffenes Stahlbauteil geschaffen werden.Against the background of the prior art explained above, the object of the invention was to provide an economical process for the production of high-strength steel components, which have optimized corrosion protection and are particularly suitable for use in automobile bodies. In addition, a suitably procured steel component should be created.

In Bezug auf das Verfahren ist diese Aufgabe erfindungsgemäße dadurch gelöst worden, dass bei der Herstellung eines Stahlbauteils die in Anspruch 1 angegebenen Arbeitsschritte durchlaufen werden. Vorteilhafte Ausgestaltungen dieses Verfahrens sind in den auf Anspruch 1 rückbezogenen Ansprüchen angegeben.With regard to the method, this object has been achieved according to the invention in that in the production of a steel component, the operations specified in claim 1 are performed. Advantageous embodiments of this method are specified in the dependent claims on claim 1.

In Bezug auf das Stahlbauteil ist diese Aufgabe erfindungsgemäß dadurch gelöst worden, dass ein solches Stahlbauteil gemäß Anspruch 27 ausgebildet ist. Vorteilhafte Ausgestaltungen dieses Bauteils sind in den von Anspruch 27 abhängigen Ansprüchen genannt.With regard to the steel component, this object has been achieved according to the invention in that such a steel component is designed according to claim 27. Advantageous embodiments of this component are mentioned in the dependent of claim 27 claims.

Gemäß der Erfindung wird auf einem aus einem niedrig legierten Vergütungsstahl erzeugten Stahlflachprodukt eine metallische Beschichtung erzeugt, die aus zwei in zwei Verfahrensschritten nacheinander aufgebrachten Schichten gebildet ist. Bei dem Vergütungsstahl kann es sich beispielsweise um einen Mn-B-Stahl handeln, wie er bereits im Stand der Technik vielfach eingesetzt wird.According to the invention, a metallic coating is produced on a flat steel product produced from a low-alloy tempered steel, which consists of two successively applied in two process steps Layers is formed. The tempering steel may be, for example, a Mn-B steel, as it is already widely used in the prior art.

Gemäß der Erfindung wird im ersten Arbeitsschritt das aus dem geeignet zusammengesetzten Vergütungsstahl erzeugte Stahlflachprodukt mit einem Al-Überzug, der mindestens 85 Gew.-% Al enthält, wobei zusätzlich Gehalte von bis zu 15 Gew.-% Si in dem erfindungsgemäß aufgetragenen Al-Überzug vorhanden sind. Typische Varianten der erfindungsgemäß aufgetragenen Al-Beschichtung sind ein fast vollständig aus Al bestehender Überzug oder eine AlSi-Variante, bei der der Si-Gehalt des aufgetragenen AlSi-Überzugs 8 - 12 Gew.-% Si beträgt.According to the invention, in the first step, the flat steel product produced from the suitably composed tempering steel is provided with an Al coating containing at least 85% by weight of Al, with additional contents of up to 15% by weight of Si in the Al coating applied according to the invention available. Typical variants of the Al coating applied according to the invention are a coating consisting almost entirely of Al or an AlSi variant in which the Si content of the applied AlSi coating is 8-12% by weight Si.

Anschließend wird auf diesen Al-Überzug ein Zn-Überzug aufgetragen, der zu mindestens 90 Gew.-% aus Zink besteht.Subsequently, a Zn coating is applied to this Al-coating, which consists of at least 90 wt .-% of zinc.

Vor der Umformung zum jeweiligen Bauteil wird das derart zweischichtig beschichtete Stahlflachprodukt dann auf eine mindestens 750 °C betragende Warmformtemperatur erwärmt. Dabei kommt es zur Ausbildung einer aus Al, Fe, Zn und Si legierten Grundschicht, an der Al den größten Anteil hat, jedoch auch Fe, Zn und Si als wesentliche Bestandteile hervortreten. In der Praxis werden erfindungsgemäß typischerweise Warmformtemperaturen von 850 bis 950 °C, insbesondere 850 - 900 °C, eingestellt.Before the forming of the respective component, the two-layered coated flat steel product is then heated to at least 750 ° C hot forming temperature. This results in the formation of an alloyed Al, Fe, Zn and Si base layer in which Al has the largest share, but Fe, Zn and Si emerge as essential ingredients. In practice, thermoforming temperatures of 850 to 950 ° C., in particular 850 to 900 ° C., are typically set according to the invention.

Das auf die Warmformtemperatur erwärmte Stahlflachprodukt wird in einem weiteren Arbeitsschritt in an sich bekannter Weise zum jeweiligen Bauteil warmgeformt und in einer für die gewünschte Ausbildung des Vergütungs- bzw. Härtegefüges beschleunigt abgekühlt.The heated to the hot forming temperature flat steel product is thermoformed in a further step in a conventional manner to the respective component and in one accelerated for the desired training of the tempering or hardening structure accelerated.

Bei den voranstehend aufgezählten Arbeitsschritten handelt es sich um die Maßnahmen, die mindestens notwendig sind, um den erfindungsgemäß erzielten Erfolg zu erreichen. Selbstverständlich können zusätzliche Schritte vorgesehen werden, wenn dies sich aus produktionstechnischer Sicht für notwendig erweist.The steps listed above are the measures that are at least necessary in order to achieve the success achieved according to the invention. Of course, additional steps can be provided if this proves necessary from a production point of view.

So kann dem Erwärmen auf die Warmformtemperatur beispielsweise ein Zerteilen des zuvor als Band vorliegenden in der erfindungsgemäßen Weise zweischichtig überzogenen Flachprodukts zu Platinen vorausgehen. Darüber hinaus kann den einzelnen Beschichtungsschritten jeweils eine Reinigung der Oberfläche des Stahlflachproduktes bzw. der darauf aufgetragenen Beschichtung vorangehen.For example, the heating to the thermoforming temperature can be preceded by a division of the flat product, which has previously been present as a strip in the manner according to the invention in two layers, into sheets. In addition, each of the individual coating steps may be preceded by a cleaning of the surface of the flat steel product or the coating applied thereto.

Überraschend hat sich zunächst gezeigt, dass das in erfindungsgemäßer Weise beschichtete Stahlflachprodukt sich problemlos zu einem Stahlbauteil umformen lässt. So erwies sich erfindungsgemäß beschichtetes Stahlflachprodukt sowohl für eine direkte, d. h als einstufiger Arbeitsschritt ohne vorhergehende Kaltverformung durchgeführte Warmformgebung, als auch für eine indirekte, d. h. mindestens zweistufige, durch eine Aufeinanderfolge von Kaltverformung und Warmverformung gekennzeichnete Formgebung geeignet.Surprisingly, it has initially been shown that the steel flat product coated in accordance with the invention can be easily converted into a steel component. Thus, according to the invention coated flat steel product proved both for a direct, d. h as a one-step work step without previous cold forming performed thermoforming, as well as for an indirect, d. H. at least two-stage shaping characterized by a succession of cold working and hot working.

Nach der jeweils durchgeführten Warmformgebung liegt bei einem erfindungsgemäßen Stahlbauteil eine zinklegierte Oberfläche mit einem Zink-Gehalt von mindesten 60 Gew.-%, insbesondere von mindestens 80 Gew.-%, vor. Daraus resultiert ein kathodischer Korrosionsschutz, der elektrochemisch eindeutig nachweisbar ist. So konnte im beschleunigten Korrosionstest (Salzsprühnebeltest) nachgewiesen werden, dass erfindungsgemäß erzeugte Überzüge eine Beständigkeit gegen Korrosion besitzen, die mit reinen Zinküberzügen mindestens vergleichbar sind.After each thermoforming carried out in a steel component according to the invention is a zinc alloy Surface having a zinc content of at least 60 wt .-%, in particular of at least 80 wt .-%, before. This results in a cathodic corrosion protection, which is clearly detectable electrochemically. Thus, it could be demonstrated in the accelerated corrosion test (salt spray test) that coatings produced according to the invention have a resistance to corrosion which is at least comparable to pure zinc coatings.

Aus dem Umstand, dass bis zu 30 % Al in der Deckschicht des erfindungsgemäß erhaltenen Stahlbauteils vorhanden sein können, ergeben sich zusätzliche Vorteile in Bezug auf den Korrosionsschutz.From the fact that up to 30% Al can be present in the top layer of the steel component obtained according to the invention, additional advantages with regard to corrosion protection result.

Die einen hohen Anteil an Al aufweisende, zwischen der Zn-dominierten Deckschicht und dem jeweiligen Stahlsubstrat angeordnete Grundschicht des erfindungsgemäß erzeugten metallischen Gesamtüberzugs schützt diesen vor einer übermäßigen Zink- und Eisendiffusion während der Wärmebehandlung bei den erfindungsgemäß bevorzugt im Bereich von 750 bis 900 °C, insbesondere 850 bis 900 °C gewählten Warmformtemperaturen. Als Vorteile der Sperrwirkung der Grundschicht ist zum einen eine verzögerte Rotrostbildung an der Oberfläche zu nennen. Zum anderen verhindert die Grundschicht, dass Zink auf die Korngrenzen des Stahlsubstrats gelangen kann, was die Gefahr einer Rissbildung bei der Warmumformung zur Folge hätte. Die Al-Fe-Zn-Si-haltige Grundschicht des erfindungsgemäß erzeugten Gesamtüberzuges schützt das Stahlsubstrat darüber hinaus besonders wirksam gegen eine Oxidation mit dem Sauerstoff der Umgebung.The high level of Al having, between the Zn-dominated top layer and the respective steel substrate arranged base layer of the metallic total coating produced according to the invention protects it against excessive zinc and iron diffusion during the heat treatment in accordance with the invention preferably in the range of 750 to 900 ° C, in particular 850 to 900 ° C selected thermoforming temperatures. One of the advantages of the barrier effect of the base layer is the delayed formation of red rust on the surface. On the other hand, the base layer prevents zinc from reaching the grain boundaries of the steel substrate, which would lead to the risk of cracking during hot forming. The Al-Fe-Zn-Si-containing base layer of the total coating produced according to the invention moreover protects the steel substrate particularly effectively against oxidation with the oxygen of the environment.

Mit der erfindungsgemäßen Vorgehensweise steht somit eine besonders wirtschaftlich durchführbare Möglichkeit der Herstellung von optimiert korrosionsgeschützten Bauteilen aus hochfesten warmpressformbaren Stählen zur Verfügung.Thus, with the procedure according to the invention, a particularly economically feasible option is available for the production of optimized corrosion-protected components made of high-strength hot-press-formable steels.

Ein in erfindungsgemäßer Weise beschaffenes Stahlbauteil trägt den voranstehend zusammengefassten Erkenntnissen folgend eine metallische Beschichtung, die durch eine auf dem Stahlflachprodukt aufliegenden Grundschicht und einer auf der Grundschicht liegenden Deckschicht gebildet ist, wobei die Grundschicht mindestens 30 Gew.-% Al, mindestens 20 Gew.-% Fe und mindestens 3 Gew.-% Si enthält und die Deckschicht mindestens 60 Gew.-% Zn, insbesondere mindestens 80 Gew.-%, und mindestens 5 Gew.-% Al sowie bis zu 10 Gew.-% Fe und bis zu 10 Gew.-% Si aufweist.According to the findings summarized above, a steel component obtained in accordance with the invention bears a metallic coating which is formed by a base layer resting on the flat steel product and a cover layer lying on the base layer, the base layer containing at least 30% by weight Al, at least 20% by weight. % Fe and at least 3 wt .-% Si and the top layer at least 60 wt .-% Zn, in particular at least 80 wt .-%, and at least 5 wt .-% Al and up to 10 wt .-% Fe and up to 10 wt .-% Si has.

Besonders wirtschaftlich bei gleichzeitig optimalem Beschichtungsergebnis kann der Al-Überzug durch Feueraluminieren als erste Überzugsschicht auf das jeweilige Stahlflachprodukt aufgebracht werden.Particularly economical with the same optimum coating result, the Al-coating can be applied by fire aluminizing as the first coating layer on the respective flat steel product.

Der Zn-Überzug kann dann ebenfalls besonders wirtschaftlich in vergleichbarer, an sich bekannter und in der Praxis bewährten Weise durch ein Feuerverzinken auf die zuvor auf das Stahlflachprodukt aufgebrachte Al-Schicht aufgetragen werden.The Zn coating can then also be applied particularly economically in a comparable, known manner and proven in practice by hot-dip galvanizing onto the Al layer previously applied to the flat steel product.

Besonders gute Beschichtungserfolge lassen sich darüber hinaus dadurch erzielen, wenn der Zn-Überzug alternativ zu einem Feuerverzinken elektrolytisch auf dem Al-Überzug abgeschieden wird. Beim elektrolytischen Verzinken wird bevorzugt eine Schicht mit einem Zn-Gehalt von mindestens 99 Gew.-% abgeschieden.In addition, particularly good coating results can be achieved if the Zn coating is deposited electrolytically on the Al coating as an alternative to hot-dip galvanizing. When electrolytic galvanizing is preferably a layer with a Zn content of at least 99 wt .-% deposited.

Eine weitere alternative Möglichkeit des Auftrags der Zn-Schicht besteht darin, dass der Zn-Überzug in einem PVD-Verfahren auf dem Al-Überzug abgeschieden wird. Die Nutzung des PVD-Verfahrens (PVD = Physical Vapor Deposition) für den Auftrag der Zn-Schicht erlaubt eine besonders exakte Einstellung der Schichtdicke.Another alternative way of applying the Zn layer is to deposit the Zn coating on the Al coating in a PVD process. The use of the PVD method (PVD = Physical Vapor Deposition) for the application of the Zn layer allows a particularly exact adjustment of the layer thickness.

Beim Feuerverzinken und beim Auftrag mittels PVD-Verfahren können neben Zn mindestens ein weiteres Element aus Al, Mg oder Fe enthalten sein. Vorteilhafterweise sollten die Gehalte 5 Gew.-% Al, 5 Gew.-% Mg und/oder 0,5 Gew.-% Si nicht überschreiten.When hot-dip galvanizing and when applying by PVD method Zn at least one other element of Al, Mg or Fe may be included. Advantageously, the contents should not exceed 5% by weight Al, 5% by weight Mg and / or 0.5% by weight Si.

Die Gehalte an weiteren Begleitelementen im Zn-Überzug, wie z.B. Pb, Bi, Cd, Ti, Cu, Cr oder Ni, sollten in Summe 1 Gew.-% nicht überschreiten.The contents of other accompanying elements in the Zn coating, such as e.g. Pb, Bi, Cd, Ti, Cu, Cr or Ni, should not exceed 1 wt .-% in total.

Zur Einstellung einer die Benetzbarkeit und Anbindung der anschließend aufgetragenen Zn-Schicht verbessernden Oberflächenrauhigkeit kann es zweckmäßig sein, das mit dem Al-Überzug versehene Stahlflachprodukt vor dem Auftrag des Zn-Überzugs einem Dressierwalzen zu unterziehen.In order to set a surface roughness which improves the wettability and bonding of the subsequently applied Zn layer, it may be expedient to subject the flat steel product provided with the Al coating to temper rolling before application of the Zn coating.

Für denselben Zweck kann es vorteilhaft sein, das mit dem Al-Überzug versehene Stahlflachprodukt vor dem Auftrag des Zn-Überzugs zu dekapieren. Beim Dekapieren werden die erfindungsgemäß beschichteten Flachprodukte durch ein Säurebad geleitet, das die Oxidschicht von ihnen abspült, ohne die Oberfläche des Stahlflachprodukts selbst anzugreifen. Durch den gezielt durchgeführten Schritt der Dekapierung wird der Oxidabtrag so gesteuert, dass man eine für die elektrolytische Bandverzinkung günstig eingestellte Oberfläche erhält.For the same purpose, it may be advantageous to decap the Al-coated flat steel product prior to application of the Zn coating. During pickling, the flat products coated according to the invention are passed through an acid bath which rinses the oxide layer off them, without attacking the surface of the flat steel product itself. By the deliberately carried out step of pickling the Oxidabtrag is controlled so that you get a favorable set for the electrolytic strip galvanizing surface.

In manchen Fällen, insbesondere bei einer nicht kontinuierlichen Durchführung der Verfahrensschritte, ist es vorteilhaft, zusätzlich vor dem Dekapieren eine alkalische Reinigung durchzuführen.In some cases, in particular in a non-continuous implementation of the method steps, it is advantageous to additionally perform an alkaline cleaning before picking.

Besonders wirtschaftlich lässt sich das erfindungsgemäße Verfahren dann durchführen, wenn der Al-Überzug und anschließend der Zn-Überzug sowie alle zwischen den jeweiligen Beschichtungsschritten erforderlichen Arbeitsschritte in einer kontinuierlich aufeinand folgend durchlaufenen Arbeitsfolge absolviert werden.The process according to the invention can be carried out in a particularly economical manner when the Al coating and then the Zn coating and all the work steps required between the respective coating steps are completed in a sequence of operations continuously following each other.

Steht eine entsprechende Anlagentechnik nicht zur Verfügung oder erweist es sich aus sonstigen Gründen als zweckmäßig, so ist es jedoch auch problemlos möglich, den Al-Überzug und anschließend den Zn-Überzug in einer gebrochenen, diskontinuierlichen Arbeitsweise aufzubringen.If a corresponding system technology is not available or if it proves to be expedient for other reasons, then it is also easily possible to apply the Al coating and then the Zn coating in a fractured, discontinuous mode of operation.

Der besondere Vorteil der Erfindung besteht, wie bereits erläutert, darin, dass die Umformung des Stahlflachprodukts zu dem Stahlbauteil in einem einzigen Warmformschritt erfolgen kann. So erweist sich erfindungsgemäß beschichtetes Stahlband als besonders unempfindlich gegen die bei der Warmumformung in einem Zuge auftretenden Belastungen auch dann, wenn das jeweilige Bauteil eine komplexe Form erhält.The particular advantage of the invention, as already explained, is that the transformation of the flat steel product to the steel component can take place in a single thermoforming step. Thus, coated steel strip according to the invention proves to be particularly insensitive to those in hot forming in one Traces occurring even if the respective component receives a complex shape.

Genauso ist es jedoch auch möglich, die Umformung des erfindungsgemäß beschichteten Flachprodukts mehrstufig durchzuführen, wobei jeweils mindestens eine Umformstufe als auf die Erwärmung auf Warmformtemperatur folgender Warmformschritt ausgeführt wird. Dementsprechend kann, wenn sich dies aus produktionstechnischer Sicht als vorteilhaft erweist, das Stahlflachprodukt vor der Erwärmung auf die Warmformtemperatur mindestens einen Kaltumformschritt durchlaufen. Dabei kann die Verformung fast vollständig bei der Kaltumformung erfolgen, so dass in diesem Fall der nach der Kaltverformung durchgeführte Warmformschritt eher ein Warmkalibrieren mit anschließendem Abschrecken im Werkzeug darstellt.Equally, however, it is also possible to carry out the forming of the flat product coated according to the invention in several stages, wherein in each case at least one forming step is carried out as the warm forming step following the hot forming temperature. Accordingly, if this proves to be advantageous from a production point of view, the flat steel product may undergo at least one cold forming step before being heated to the hot forming temperature. In this case, the deformation can take place almost completely during the cold forming, so that in this case the hot forming step carried out after the cold forming represents rather a warm calibration with subsequent quenching in the tool.

Besonders gute Arbeitsergebnisse stellen sich ein, wenn der auf das Stahlflachprodukt aufgetragene Al-Überzug vor der Erwärmung auf die Warmformtemperatur eine Dicke von 5 - 25 µm, insbesondere von 5 - 15 µm, und der auf den AlSi-Überzug aufgetragene Zn-Überzug vor der Erwärmung auf die Warmformtemperatur eine Dicke von 2 - 10 µm aufweist. Dabei haben Untersuchungen ergeben, dass insbesondere dann, wenn der AlSi-Überzug durch Feueraluminieren aufgetragen wird, vor der Erwärmung auf die Warmformtemperatur zwischen dem Stahlflachprodukt und dem entsprechend aufgetragenen AlSi-Uberzug eine 2 - 5 µm dicke, Al, Si und Fe enthaltende Legierungsgrenzschicht vorhanden ist. Unter Berücksichtigung der voranstehend genannten Dicken seiner einzelnen Schichten weist eine erfindungsgemäß in zwei Arbeitsgängen auf das zu verformende Flachprodukt aufgebrachte metallische Beschichtung typischerweise eine Gesamtdicke von 7 - 35 µm auf.Particularly good results are obtained when the Al coating applied to the flat steel product before heating to the thermoforming temperature has a thickness of 5 to 25 μm, in particular 5 to 15 μm, and the Zn coating applied to the AlSi coating Heating to the thermoforming temperature has a thickness of 2 - 10 microns. Examinations have shown that especially when the AlSi coating is applied by fire aluminizing, prior to heating to the thermoforming temperature between the flat steel product and the correspondingly applied AlSi coating, there is a 2-5 μm thick alloy boundary layer containing Al, Si and Fe is. Taking into account the above-mentioned thicknesses of its individual layers, an invention according to the invention in two operations to deforming flat product applied metallic coating typically has a total thickness of 7 - 35 microns on.

Wie erläutert, ist bei einem erfindungsgemäß fertig geformten bzw. beschaffenen Bauteil eine unmittelbar auf dem Stahlflachprodukt aufliegende zum überwiegenden Teil aus Al und zusätzlichen Gehalten an Fe, Zn und Si bestehende Grundschicht vorhanden ist, auf der eine zum überwiegenden Teil aus Zn und zusätzlichen Gehalten aus Al, Si und Fe bestehende Deckschicht liegt. Die Grundschicht weist dabei mindestens 30 Gew.-% Al, mindestens 20 Gew.-% Fe, mindestens 3 Gew.-% Si und höchstens 30 Gew.-% Zn auf, während in der Deckschicht mindestens 60 Gew.-%, insbesondere mindestens 80 Gew.-%, Zn mindestens 5 Gew.-% Al sowie maximal 10 Gew.-% Fe und maximal 10 Gew.-% Si vorhanden sind.As explained, in an inventively finished or produced component there is a base layer which is directly on the flat steel product and consists predominantly of Al and additional Fe, Zn and Si contents, on which predominantly Zn and additional contents are present Al, Si and Fe existing cover layer is located. The base layer has at least 30 wt .-% Al, at least 20 wt .-% Fe, at least 3 wt .-% Si and at most 30 wt .-% Zn, while in the top layer at least 60 wt .-%, in particular at least 80 wt .-%, Zn at least 5 wt .-% Al and at most 10 wt .-% Fe and at most 10 wt .-% Si are present.

Die Dicke der Grundschicht des erfindungsgemäß fertig geformten Bauteils beträgt typischerweise 10 - 50 µm, insbesondere 15 - 25 µm, während die Dicke der Deckschicht typischerweise im Bereich von 5 - 20 µm, insbesondere 3 - 10 µm, liegt.The thickness of the base layer of the finished molded component according to the invention is typically 10 to 50 μm, in particular 15 to 25 μm, while the thickness of the cover layer is typically in the range of 5 to 20 μm, in particular 3 to 10 μm.

Nachfolgend wird die Erfindung anhand von Ausführungsbeispielen näher erläutert. Es zeigen:

Fig. 1
eine schematische Darstellung eines ersten erfindungsgemäßen Arbeitsablaufs bei der Beschichtung eines Stahlflachproduktes;
Fig. 2
eine schematische Darstellung eines zweiten erfindungsgemäßen Arbeitsablaufs bei der Beschichtung eines Stahlflachproduktes;
Fig. 3
eine schematische Darstellung eines dritten erfindungsgemäßen Arbeitsablaufs bei der Beschichtung eines Stahlflachproduktes;
Fig. 4
eine schematische Darstellung eines vierten erfindungsgemäßen Arbeitsablaufs bei der Beschichtung eines Stahlflachproduktes;
Fig. 5
eine schematische Darstellung eines fünften erfindungsgemäßen Arbeitsablaufs bei der Beschichtung eines Stahlflachproduktes;
Fig. 6
einen Vergleich des Schichtaufbaus auf einem erfindungsgemäß beschichteten Stahlflachprodukt vor und nach der Erwärmung auf Warmformtemperatur;
Fig. 7
das Ergebnis einer Ruhepotenzialmessung an verschiedenen Proben;
Fig. 8
einen Ausschnitt eines Schliffbilds eines erfindungsgemäß beschichteten Stahlflachprodukts vor dem Erwärmen auf Umformtemperatur;
Fig. 9
einen Ausschnitt eines Schliffbilds eines erfindungsgemäß beschichteten Stahlflachprodukts nach dem Erwärmen auf Umformtemperatur.
The invention will be explained in more detail by means of exemplary embodiments. Show it:
Fig. 1
a schematic representation of a first workflow according to the invention in the coating of a flat steel product;
Fig. 2
a schematic representation of a second workflow according to the invention in the coating of a flat steel product;
Fig. 3
a schematic representation of a third inventive workflow in the coating of a flat steel product;
Fig. 4
a schematic representation of a fourth inventive workflow in the coating of a flat steel product;
Fig. 5
a schematic representation of a fifth inventive workflow in the coating of a flat steel product;
Fig. 6
a comparison of the layer structure on a coated steel flat product according to the invention before and after the heating to thermoforming temperature;
Fig. 7
the result of a resting potential measurement on different samples;
Fig. 8
a section of a micrograph of a coated steel flat product according to the invention before heating to forming temperature;
Fig. 9
a section of a micrograph of a coated steel flat product according to the invention after heating to forming temperature.

In den Figuren 1 bis 5 sind verschiedene Möglichkeiten der praktischen Umsetzung des erfindungsgemäßen Verfahrens beispielhaft angegeben. Dabei gehen die betreffenden Beispiele jeweils aus von einem kaltgewalzten Stahlband, das beispielsweise aus dem bekannten 22MnB5-Stahl erzeugt ist.In the FIGS. 1 to 5 various possibilities of practical implementation of the method according to the invention are given by way of example. In each case, the respective examples are based on a cold-rolled steel strip which is produced, for example, from the known 22MnB5 steel.

Bei der in Fig. 1 angegebenen Verfahrensweise werden die Arbeitsschritte Reinigen, Feueraluminieren (d. h.: Glühen, Durchleiten durch ein AlSi-Schmelztauchbad), Dressieren und elektrolytisches Beschichten in einer kontinuierlich durchlaufenen Arbeitsfolge absolviert.At the in Fig. 1 the procedure described cleaning the work, fire aluminizing (ie: annealing, passing through an AlSi hot dip), dressing and electrolytic coating completed in a continuous work sequence.

Fig. 2 zeigt ein Beispiel, bei der die in Fig. 1 angegebenen Arbeitsschritte durchlaufen werden, jedoch nicht in einer kontinuierlichen, sondern in einer gebrochenen Arbeitsfolge. So wird bei dem in Fig. 2 angegebenen Beispiel nach dem Dressieren des zuvor feueraluminierten Stahlbands das Band zu einem Coil gewickelt, zu einer elektrolytisch arbeitenden Beschichtungseinrichtung verbracht, dort gereinigt und dekapiert und sodann elektrolytisch mit der auf die AlSi-Beschichtung aufgetragenen Zn-Beschichtung versehen. Fig. 2 shows an example where the in Fig. 1 are passed through specified work steps, but not in a continuous, but in a broken sequence. So is in the in Fig. 2 Example given after the passing of the previously hot-rolled steel strip, the strip wound into a coil, brought to an electrolytic coating device, cleaned there and dekapiert and then provided electrolytically with the applied to the AlSi coating Zn coating.

Beim in Fig. 3 angegebenen Beispiel werden die Arbeitsschritte Reinigen des Kaltbands, Feueraluminieren (d. h.: Glühen und Durchleiten durch ein AlSi-Schmelzenbad), Feuerverzinken (d. h.: Kühlen auf die Badeintrittstemperatur und Durchleiten durch ein Zn-Schmelzenbad) sowie Dressieren in einem kontinuierlichen Arbeitsablauf durchlaufen, während beim in Fig. 4 dargestellten Beispiel dieselben Arbeitsschritte insofern diskontinuierlich absolviert werden, als dort nach dem Feueraluminieren das mit der AlSi-Beschichtung versehene Band auf Raumtemperatur abgekühlt und zu einer Feuerverzinkungsanlage verbracht wird, bevor es dort wieder geglüht und durch das Schmelzenbad geleitet wird.When in Fig. 3 In the example given, the cold strip cleaning, fire aluminizing (ie: annealing and passing through an AlSi melt bath), hot dip galvanizing (ie, cooling to the bath inlet temperature and passing through a Zn melt bath), and skin pass coating operations are performed in a continuous process while the in-line Fig. 4 illustrated example, the same steps so far be completed discontinuously, as there after the fire aluminizing provided with the AlSi coating tape is cooled to room temperature and placed in a hot-dip galvanizing plant before being annealed there and passed through the melt bath.

Fig. 5 gibt schließlich ein Beispiel für eine Verfahrensweise an, bei der das Stahlband zunächst gereinigt wird, dann feueraluminiert wird (d. h.: geglüht und durch ein AlSi-Schmelzenbad geleitet wird), anschließend dressiergewalzt wird, daraufhin gereinigt wird und schließlich durch Anwendung eines PVD-Verfahrens mit der Zn-Schicht beschichtet wird. Fig. 5 Finally, there is an example of a procedure in which the steel strip is first cleaned, then fire-aluminized (ie annealed and passed through an AlSi melt bath), then finish rolled, then cleaned, and finally by using a PVD method the Zn layer is coated.

Fig. 6 zeigt in ihrer linken Hälfte den Schichtaufbau eines Überzugs, wie er bei erfindungsgemäßer Vorgehensweise vor der Erwärmung auf Warmformtemperatur vorhanden ist. Demnach ist zwischen dem Stahlsubstrat und der darüber liegenden, typischerweise 90 Gew.-% und 10 Gew.-% Si enthaltenden AlSi-Schicht eine Legierungsschicht ausgebildet, die Al, Si und Fe enthält. Die AlSi-Schicht ("erste Schicht") und die Legierungsschicht bilden gemeinsam die "Grundschicht" des Gesamtüberzugs. Auf der "Grundschicht" ist als "Deckschicht" die Zn-Schicht ("zweite Schicht") aufgetragen, die typischerweise zu 99 Gew.-% aus Zn und weniger als 1 Gew.-% aus Al besteht. Fig. 6 shows in its left half the layer structure of a coating, as it is present in the inventive procedure before heating to thermoforming temperature. Accordingly, an alloy layer containing Al, Si and Fe is formed between the steel substrate and the overlying AlSi layer containing typically 90 wt% and 10 wt% Si. The AlSi layer ("first layer") and the alloy layer together form the "base layer" of the overall coating. The Zn layer ("second layer"), which typically consists of 99% by weight of Zn and less than 1% by weight of Al, is applied to the "base layer" as the "top layer".

In der rechten Hälfte von Fig. 6 ist der Schichtaufbau des Gesamtüberzugs dargestellt, der sich bei einer über fünf Minuten erstreckenden Erwärmung des in der linken Hälfte dargestellten Schichtaufbaus auf eine Temperatur von 900 °C einstellt. Demnach ist nach dieser Erwärmung auf dem Stahlsubstrat eine zu 40 Gew.-% aus Al, zu 30 Gew.-% aus Fe, zu 20 Gew.-% aus Zn und zu 5 Gew.-% aus Si bestehende Grundschicht vorhanden, auf der eine zu 80 Gew.-% aus Zn, zu 16 Gew.-% aus Al, zu 2 Gew.-% aus Si und zu 2 Gew.-% aus Fe bestehende Deckschicht liegt. Deckschicht und Grundschicht bilden auch dort gemeinsam den Gesamtüberzug.In the right half of Fig. 6 shows the layer structure of the overall coating, which is at a temperature of more than five minutes extending heating of the layer structure shown in the left half of 900 ° C. Accordingly, after this heating on the steel substrate, a base layer consisting of 40% by weight of Al, 30% by weight of Fe, 20% by weight of Zn and 5% by weight of Si, on which a covering layer consisting of 80% by weight of Zn, 16% by weight of Al, 2% by weight of Si and 2% by weight of Fe. Cover layer and base layer together form the total coating there as well.

Anhand von Ruhepotenzialmessungen, deren Ergebnisse in Fig. 7 zusammengefasst sind, ist die kathodische Schutzwirkung des erfindungsgemäß erzeugten, nach einer Erwärmung auf eine Warmformtemperatur von 880 °C erhaltenen Überzugs nachgewiesen worden (Kurve "AS+Zn, geglüht 880 °C"). Es zeigte sich, dass die kathodische Schutzwirkung des erfindungsgemäß erzeugten Überzugs besser ist als die Wirkung eines konventionellen Zn-Überzugs nach einer Erwärmung auf 880 °C (Kurve "Z geglüht 880 °C") und der Schutzwirkung eines ungeglühten Zn-Überzugs (Kurve "Z ungeglüht") annähernd gleich kommt. Auch haben die Ruhepotenzialmessungen bestätigt, dass ein konventioneller AlSi-Überzug (Kurve "AS geglüht 950 °C") nach einer Erwärmung auf die in diesem Fall für das Warmformen geforderte Warmformtemperatur von 950 °C keine Verbesserung des kathodischen Schutzes gegenüber einem nicht beschichteten, ungeglühten Feinblech (Kurve "Feinblech ungeglüht") ergibt.On the basis of resting potential measurements, the results in Fig. 7 are summarized, the cathodic protection of the present invention, after heating to a thermoforming temperature of 880 ° C obtained coating has been detected (curve "AS + Zn, annealed 880 ° C"). It was found that the cathodic protective effect of the coating produced according to the invention is better than the effect of a conventional Zn coating after heating to 880 ° C. (curve "Z annealed 880 ° C.") and the protective effect of an unannealed Zn coating (curve " Z unannealed ") comes approximately the same. Also, the quiescent potential measurements confirmed that a conventional AlSi coating (curve "AS annealed 950 ° C") after heating to the hot forming temperature of 950 ° C required for thermoforming did not improve the cathodic protection over uncoated, unirradiated Sheet (curve "sheet unground") yields.

Zur Erprobung des erfindungsgemäßen Verfahrens sind eine Vielzahl von Versuchen durchgeführt worden, von denen nachstehend drei beispielhaft erläutert werden:To test the method according to the invention, a large number of experiments have been carried out, of which three are explained by way of example below:

Versuch 1:Trial 1:

Ein Stahlband aus einem härtbaren Stahl mit einem Kohlenstoff-Gehalt von 0,22 %, einem Mn-Gehalt von 1,2 %, einem Cr-Gehalt von 0,20 % und einem B-Gehalt von 0,003 % ist als kaltgewalztes Band in an sich bekannter Weise in einer kontinuierlichen Schmelztauchbeschichtungslinie geglüht und mit einer AlSi-Schmelze beschichtet worden. Dazu ist das Band zunächst in einem Reinigungsteil von den Schmutzrückständen aus dem Kaltwalzprozess gereinigt worden und hat dann einen Glühofen durchlaufen, indem es auf 750 °C erwärmt worden ist.A steel strip made of a hardenable steel having a carbon content of 0.22%, a Mn content of 1.2%, a Cr content of 0.20% and a B content of 0.003% is referred to as a cold-rolled strip in annealed in a continuous hot dip coating line and coated with an AlSi melt. For this purpose, the tape was first cleaned in a cleaning part of the debris from the cold rolling process and then went through an annealing furnace by being heated to 750 ° C.

Bei dieser Temperatur ist das Band im Glühofen in einer Schutzgasatmosphäre mit 10 % H2 und Rest N2 rekristallisierend geglüht worden.At this temperature, the strip has been recrystallized in the annealing furnace in a protective gas atmosphere with 10% H 2 and balance N 2 recrystallizing.

Nach Abkühlen auf eine Temperatur von 680 °C (ebenfalls noch unter Schutzgas 10 % H2, Rest N2) ist das Band in ein Aluminiumbad mit einer Temperatur von 660 °C eingetreten. Neben Al enthielt das Aluminiumbad zusätzlich ca. 10 Gew.-% Silizium.After cooling to a temperature of 680 ° C (also still under inert gas 10% H 2 , balance N 2 ), the tape has entered an aluminum bath with a temperature of 660 ° C. In addition to Al, the aluminum bath additionally contained about 10% by weight of silicon.

Nach dem Herausziehen des Bandes aus dem Schmelzbad ist mittels Düsenabstreifsystem eine Überzugsdicke von 18 µm eingestellt worden.After the tape has been pulled out of the molten bath, a coating thickness of 18 μm has been set by means of the nozzle scraping system.

Nach Abkühlung des Bandes auf < 50 °C erfolgt durch Dressierwalzen in einem Dressiergerüst die Einstellung der Oberflächenrauheit des mit der AlSi-Beschichtung versehenen Bandes.After the strip has been cooled to <50 ° C., the surface roughness of the strip provided with the AlSi coating is adjusted by temper rolling in a skin pass mill.

In einem folgenden Abschnitt der Produktionslinie ist das Band dann zunächst in einer wässrigen Lösung mit 80 g/l HCl (Salzsäure) für 10 s bei 40 °C chemisch behandelt worden.In a subsequent section of the production line, the strip was then first chemically treated in an aqueous solution with 80 g / l HCl (hydrochloric acid) for 10 s at 40 ° C.

Danach erfolgte in Elektrolysezellen die elektrolytische Abscheidung von 7 µm Zink aus einem Zinksulfat-Elektrolyten bei einer Stromdichte von rd. 50 A/dm2 und einer Elektrolyttemperatur von rd. 60 °C auf der Oberfläche des AlSi-Überzuges.This was followed in electrolysis cells, the electrolytic deposition of 7 microns zinc from a zinc sulfate electrolyte at a current density of approx. 50 A / dm 2 and an electrolyte temperature of approx. 60 ° C on the surface of the AlSi coating.

Abschließend ist das Band zu einem fertigen Coil aufgehaspelt worden.Finally, the tape has been wound into a finished coil.

Aus dem beschichteten Band sind Platinen zugeschnitten und zunächst in einer Umformpresse kalt vorgeformt worden. Die vorgeformten Teile sind dann in einem Ofen auf eine Warmformtemperatur von 880 °C für 5 min erwärmt worden. Der vor der Erwärmung auf die Warmformtemperatur vorhandene Schichtaufbau ist in Fig. 8 dargestellt.From the coated tape boards have been cut and first cold preformed in a forming press. The preformed parts were then heated in an oven to a thermoforming temperature of 880 ° C for 5 minutes. The existing before the heating to the hot forming temperature layer structure is in Fig. 8 shown.

Anschließend sind die erwärmten Platinen mittels eines Manipulators in eine Warmumformpresse überführt und dort zu einem fertigen Bauteil umgeformt und im Werkzeug in bekannter Weise schnell abgekühlt worden. In Fig. 9 ist die für die auf dem so erzeugten Bauteil vorhandene Gesamtbeschichtung dargestellt.Subsequently, the heated blanks are transferred by means of a manipulator in a hot forming press and formed there to a finished component and cooled quickly in the tool in a known manner. In Fig. 9 is shown for the existing on the thus produced component total coating.

Versuch 2:Trial 2:

Ein Stahlband aus einem härtbaren Stahl ist als kaltgewalztes Band in einer kontinuierlichen Schmelztauchbeschichtungslinie geglüht und beschichtet worden. Dabei ist das Band zunächst wie im Beispiel 1 gereinigt und geglüht worden. Anschließend hat es ein Aluminium-Siliziumbad (Si-Anteil 10 %) durchlaufen, dessen Temperatur 660 °C betrug. Die anschließend mittels Abstreifdüsen eingestellte Dicke des erhaltenen AlSi-Überzugs betrug 15 µm. Nach einer Kühlstrecke, über die das Band auf 480 °C abkühlt worden ist, ist das Band in ein zweites Schmelzbad aus Zink eingetaucht, das mit einem Zusatz von 0,2 % Al versehen war. Mit den anschließenden Abstreifdüsen ist eine Zinküberzugsdicke von 5 µm eingestellt worden. Nach Abkühlung des Bandes auf < 50 °C erfolgte in einem Dressiergerüst die Einstellung der Oberflächenrauheit. Abschließend ist das Band zu einem fertigen Coil aufgehaspelt worden.A steel strip of a hardenable steel is as a cold-rolled strip in a continuous Hot dip coating line annealed and coated. The tape has first been cleaned and annealed as in Example 1. Subsequently, it has undergone an aluminum-silicon bath (Si content 10%) whose temperature was 660 ° C. The thickness of the resulting AlSi coating then adjusted by means of wiping nozzles was 15 μm. After a cooling section, over which the tape has been cooled to 480 ° C, the tape is immersed in a second molten bath of zinc, which was provided with an addition of 0.2% Al. With the subsequent wiping a zinc coating thickness of 5 microns has been set. After cooling the strip to <50 ° C, the setting of the surface roughness was carried out in a skin pass mill. Finally, the tape has been wound into a finished coil.

Aus dem so mit einer ersten AlSi-Schicht und einer darauf aufgetragenen zweiten Zn-Schicht beschichteten Band sind Platinen für den Warmumformprozess zugeschnitten und in einem Ofen auf 900 °C für 5 min erwärmt worden. Anschließend sind die Platinen mittels Manipulator in eine Umformpresse überführt und hier zu einem Bauteil umgeformt und im Werkzeug abgekühlt worden.From the strip thus coated with a first AlSi layer and a second Zn layer coated thereon, blanks for the hot forming process were cut and heated in an oven at 900 ° C for 5 minutes. Subsequently, the boards are transferred by manipulator in a forming press and here converted into a component and cooled in the tool.

Auch für das derart erhaltene Bauteil konnten Korrosionsschutzeigenschaften nachgewiesen werden, die den Eigenschaften entsprachen, die für das gemäß Versuch 1 erzeugte Bauteil ermittelt worden sind.Also for the thus obtained component corrosion protection properties could be detected, which corresponded to the properties that have been determined for the component produced in accordance with Experiment 1.

Versuch 3:Trial 3:

Ein Stahlband aus einem härtbaren Stahl ist als kaltgewalztes Band in einer kontinuierlichen Schmelztauchbeschichtungslinie geglüht und beschichtet worden. Dabei ist das Band zunächst wie im Beispiel 1 gereinigt, geglüht und mit einem AlSi-Überzug versehen worden. Die durch die Abstreifdüsen eingestellte Überzugsdicke beträgt in diesem Fall 20 µm. Nach Abkühlung des Bandes auf < 50 °C erfolgte durch Dressierwalzen in einem Dressiergerüst die Einstellung der Oberflächenrauheit.A steel strip of a hardenable steel has been annealed and coated as a cold rolled strip in a continuous hot dip coating line. The tape is first cleaned as in Example 1, annealed and provided with an AlSi coating. The coating thickness set by the wiping nozzles is in this case 20 μm. After cooling the strip to <50 ° C, the surface roughness was adjusted by temper rolling in a skin pass mill.

In einem darauf folgend durchlaufenen Abschnitt ist das Band zunächst alkalisch gereinigt worden, um anschließend in einem PVD-Modul mit einem Zinküberzug von 3 µm beschichtet zu werden. Abschließend ist das Band zu einem fertigen Coil aufgehaspelt worden.In a subsequently run through section, the strip was first cleaned alkaline, then to be coated in a PVD module with a zinc coating of 3 microns. Finally, the tape has been wound into a finished coil.

Aus dem so beschichteten Band sind Platinen für den Warmumformprozess zugeschnitten und in einem Ofen auf 900 °C für 5 min erwärmt worden. Anschließend sind die Platinen mittels Manipulator in eine Umformpresse überführt und hier zu einem Bauteil umgeformt und im Werkzeug beschleunigt abgekühlt worden.Blanks were cut from the coated strip for the hot forming process and heated in an oven at 900 ° C for 5 min. Subsequently, the boards are transferred by manipulator in a forming press and here converted into a component and cooled in the tool accelerated.

Auch für das derart erhaltene Bauteil konnten Korrosionsschutzeigenschaften nachgewiesen werden, die den Eigenschaften entsprachen, die für das gemäß Versuch 1 erzeugte Bauteil ermittelt worden sind.Also for the thus obtained component corrosion protection properties could be detected, which corresponded to the properties that have been determined for the component produced in accordance with Experiment 1.

Claims (30)

  1. Method for producing a steel component provided with a metallic coating which protects against corrosion, comprising the following production steps:
    - Coating a steel flat product, produced from a low-alloy heat-treated steel, with an Al coating which contains at least 85 % wt. Al, wherein additionally contents up to 15 % wt. Si are present in the applied Al coating,
    - Coating the steel flat product provided with the Al coating with a Zn coating which contains at least 90 % wt. Zn,
    - Heating the steel flat product to a hot-forming temperature which is at least 750 °C,
    - Hot forming the heated steel component made from the steel flat product, and
    - Cooling the hot-formed steel component which takes place accelerated to form a tempered or martensitic structure.
  2. Method according to Claim 1, characterised in that the hot-forming temperature is 850 to 950 °C, in particular 850 - 900 °C.
  3. Method according to Claim 1 or 2, characterised in that the Al coating is applied by hot-dip aluminising.
  4. Method according to any one of the preceding claims, characterised in that the Al coating contains 5-12 % wt. Si.
  5. Method according to any one of the preceding claims, characterised in that the Zn coating is applied by a hot-dip galvanising onto the Al layer which was previously applied onto the steel flat product.
  6. Method according to any one of Claims 1 to 4, characterised in that the Zn coating is deposited on the Al coating electrolytically.
  7. Method according to Claim 6, characterised in that the Zn coating contains at least 99 % wt. Zn.
  8. Method according to any one of Claims 1 to 4, characterised in that the Zn coating is deposited on the Al coating in a PVD process.
  9. Method according to Claim 5 or 8, characterised in that besides Zn at least one element from the group "Al, Mg, Si" is contained in the Zn coating.
  10. Method according to any one of the preceding claims, characterised in that the steel flat product provided with the Al coating is subjected to skin-pass rolling before the Zn coating is applied.
  11. Method according to any one of the preceding claims, characterised in that the steel flat product provided with the Al coating is subjected to pickling before the Zn coating is applied.
  12. Method according to any one of the preceding claims, characterised in that the Al coating and subsequently the Zn coating are applied in production steps following continuously one after the other.
  13. Method according to any one of Claims 1 to 11, characterised in that the Al coating and subsequently the Zn coating are applied in production steps which do not follow continuously one after the other.
  14. Method according to any one of the preceding claims, characterised in that the steel flat product is formed into the steel component in a single hot-forming step.
  15. Method according to any one of Claims 1 to 13, characterised in that the forming takes place in multiple stages, wherein at least one forming stage is carried out as a hot-forming step which follows on from heating to hot-forming temperature.
  16. Method according to Claim 15, characterised in that before heating to the hot-forming temperature the steel flat product passes through at least one cold-forming step.
  17. Method according to any one of the preceding claims, characterised in that before heating to the hot-forming temperature the Al coating applied onto the steel flat product has a thickness of 5 - 25 µm.
  18. Method according to any one of the preceding claims, characterised in that before heating to the hot-forming temperature the Zn coating applied onto the Al coating has a thickness of 2 - 10 µm.
  19. Method according to any one of the preceding claims, characterised in that before heating to the hot-forming temperature a 2 - 5 µm thick alloy barrier layer containing Al, Si and Fe is present between the steel flat product and the Al coating.
  20. Method according to any one of Claims 17 to 19, characterised in that the total thickness of the metal coating present on the steel flat product before heating to the hot-forming temperature is 7 - 35 µm.
  21. Method according to any one of the preceding claims, characterised in that the finish-formed steel component has a base layer, lying directly on the steel flat product, from which the steel component is formed, and predominantly consisting of Al and additional contents of Fe, Zn and Si, on which base layer a top layer predominantly consisting of Zn and additional contents of Al, Si and Fe lies.
  22. Method according to Claim 21, characterised in that the base layer has at least 30 % wt. Al, at least 20 % wt. Fe and at least 3 % wt. Si and at most 30 % wt. Zn.
  23. Method according to Claim 21 or 22, characterised in that the top layer has at least 60 % wt. Zn, at least 5 % wt. Al, as well as up to 10 % wt. Fe and up to 10 % wt. Si.
  24. Method according to any one of Claims 21 to 23, characterised in that the thickness of the base layer is 15 - 25 µm.
  25. Method according to any one of Claims 21 to 24, characterised in that the thickness of the top layer is 3 - 10 µm.
  26. Method according to any one of the preceding claims, characterised in that the steel flat product is produced from a manganese boron steel.
  27. Steel component hot-formed from a steel flat product which is produced from a low-alloy heat-treated steel and coated with a metallic coating protecting against corrosion, characterised in that the metallic coating is formed by a base layer lying on the steel flat product and by a top layer lying on the base layer, in that the base layer contains at least 30 % wt. Al, at least 20 % wt. Fe, at least 3 % wt. Si and at most 30 % wt. Zn, and in that the top layer has at least 60 % wt. Zn, at least 5 % wt. Al, up to 10 % wt. Fe and up to 10 % wt. Si.
  28. Steel component according to Claim 27, characterised in that the thickness of the base layer is 10 - 50 µm, in particular 15 - 25 µm.
  29. Steel component according to Claim 27 or 28, characterised in that the thickness of the top layer is 5 - 20 µm, in particular 3 - 10 µm.
  30. Steel component according to any one of Claims 27 to 29, characterised in that the steel flat product is produced from a manganese boron steel.
EP07117719A 2007-10-02 2007-10-02 Method for manufacturing a steel part by hot forming and steel part manufactured by hot forming Revoked EP2045360B1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP07117719A EP2045360B1 (en) 2007-10-02 2007-10-02 Method for manufacturing a steel part by hot forming and steel part manufactured by hot forming
AT07117719T ATE535631T1 (en) 2007-10-02 2007-10-02 METHOD FOR PRODUCING A STEEL COMPONENT BY HOT FORMING AND STEEL COMPONENT PRODUCED BY HOT FORMING
US12/681,286 US20100294400A1 (en) 2007-10-02 2008-10-01 Method for producing a steel component by hot forming and steel component produced by hot forming
PCT/EP2008/063139 WO2009047183A1 (en) 2007-10-02 2008-10-01 Method for the production of a steel component by thermoforming, and steel component produced by thermoforming

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP07117719A EP2045360B1 (en) 2007-10-02 2007-10-02 Method for manufacturing a steel part by hot forming and steel part manufactured by hot forming

Publications (2)

Publication Number Publication Date
EP2045360A1 EP2045360A1 (en) 2009-04-08
EP2045360B1 true EP2045360B1 (en) 2011-11-30

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EP07117719A Revoked EP2045360B1 (en) 2007-10-02 2007-10-02 Method for manufacturing a steel part by hot forming and steel part manufactured by hot forming

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US (1) US20100294400A1 (en)
EP (1) EP2045360B1 (en)
AT (1) ATE535631T1 (en)
WO (1) WO2009047183A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4071273A4 (en) * 2019-12-05 2022-10-19 Posco Steel sheet plated with al alloy and manufacturing method therefor

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009015160A1 (en) 2009-03-26 2010-09-30 Bayerische Motoren Werke Aktiengesellschaft Process for producing a coated and / or available sheet metal part with a corrosion protection coating
DE102009051673B3 (en) * 2009-11-03 2011-04-14 Voestalpine Stahl Gmbh Production of galvannealed sheets by heat treatment of electrolytically finished sheets
ES2345029B1 (en) * 2010-04-19 2011-07-18 Autotech Engineering, Aie STRUCTURAL COMPONENT OF A VEHICLE AND MANUFACTURING PROCEDURE.
DE102011051458B3 (en) * 2011-06-30 2012-07-05 Benteler Automobiltechnik Gmbh Preparing press-hardened form conservations e.g. body or structure conservations of motor cars, comprises heating a blank in a liquid bath, and press-hardening the blank in a pressing tool for forming a hot-formed mold component
US9677145B2 (en) * 2011-08-12 2017-06-13 GM Global Technology Operations LLC Pre-diffused Al—Si coatings for use in rapid induction heating of press-hardened steel
JP6113539B2 (en) * 2013-03-18 2017-04-12 日新製鋼株式会社 Manufacturing method of plated steel sheet
EP2848709B1 (en) 2013-09-13 2020-03-04 ThyssenKrupp Steel Europe AG Method for producing a steel component with an anti-corrosive metal coating and steel component
DE102014004657A1 (en) * 2014-03-29 2015-10-01 Daimler Ag Component, in particular structural component, for a motor vehicle, and method for producing a component
EP2993248B1 (en) 2014-09-05 2020-06-24 ThyssenKrupp Steel Europe AG Flat steel product with an Al coating, method for producing the same, and method for producing a hot-formed steel component
WO2016132165A1 (en) * 2015-02-19 2016-08-25 Arcelormittal Method of producing a phosphatable part from a sheet coated with an aluminium-based coating and a zinc coating
WO2018153755A1 (en) 2017-02-21 2018-08-30 Salzgitter Flachstahl Gmbh Method for coating steel sheets or steel strips and method for producing press-hardened components therefrom
DE102017208727A1 (en) 2017-05-23 2018-11-29 Thyssenkrupp Ag Improvement of cold forming suitability of aluminum based coating by alloying of alkaline earth metals
WO2020048602A1 (en) * 2018-09-06 2020-03-12 Thyssenkrupp Steel Europe Ag Galvanised cold-rolled sheet having improved tribological properties ii
WO2020048601A1 (en) * 2018-09-06 2020-03-12 Thyssenkrupp Steel Europe Ag Galvanised cold-rolled sheet having improved tribological properties i
DE102018222063A1 (en) * 2018-12-18 2020-06-18 Volkswagen Aktiengesellschaft Steel substrate for the production of a hot-formed and press-hardened sheet steel component as well as a hot-forming process
CN115261714A (en) * 2021-04-29 2022-11-01 宝山钢铁股份有限公司 Steel for pressure container and preparation method thereof
WO2023132350A1 (en) * 2022-01-06 2023-07-13 日本製鉄株式会社 Steel sheet for hot stamping, method for producing steel sheet for hot stamping, and hot-stamped molded article
WO2023132349A1 (en) * 2022-01-06 2023-07-13 日本製鉄株式会社 Steel sheet for hot stamping, method for manufacturing steel sheet for hot stamping, and hot stamp molded body
WO2023202765A1 (en) 2022-04-20 2023-10-26 Thyssenkrupp Steel Europe Ag Flat steel product having an al coating, method for the production thereof, steel component, and method for production thereof

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57200548A (en) * 1981-06-04 1982-12-08 Mitsubishi Heavy Ind Ltd Surface treated steel material
FR2780984B1 (en) * 1998-07-09 2001-06-22 Lorraine Laminage COATED HOT AND COLD STEEL SHEET HAVING VERY HIGH RESISTANCE AFTER HEAT TREATMENT
FR2787735B1 (en) * 1998-12-24 2001-02-02 Lorraine Laminage PROCESS FOR PRODUCING A WORKPIECE FROM A STRIP OF ROLLED STEEL SHEET AND ESPECIALLY HOT ROLLED
FR2807447B1 (en) * 2000-04-07 2002-10-11 Usinor METHOD FOR MAKING A PART WITH VERY HIGH MECHANICAL CHARACTERISTICS, SHAPED BY STAMPING, FROM A STRIP OF LAMINATED AND IN PARTICULAR HOT ROLLED AND COATED STEEL SHEET
DE10146791A1 (en) * 2001-09-20 2003-04-10 Sms Demag Ag Method and device for coating the surface of strand-like metallic material
DE10246614A1 (en) * 2002-10-07 2004-04-15 Benteler Automobiltechnik Gmbh Method of making vehicle component with metallic coating from steel sheet or strip, involves coating metal from non-aqueous organic solution before cold forming, hot forming and hardening
DE10333166A1 (en) * 2003-07-22 2005-02-10 Daimlerchrysler Ag Press-hardened component and method for producing a press-hardened component
JP4510488B2 (en) * 2004-03-11 2010-07-21 新日本製鐵株式会社 Hot-dip galvanized composite high-strength steel sheet excellent in formability and hole expansibility and method for producing the same
DE102004052482A1 (en) * 2004-10-28 2006-05-11 Thyssenkrupp Steel Ag Method for producing a corrosion-protected steel sheet
DE102005045780A1 (en) * 2005-09-23 2007-04-12 Thyssenkrupp Steel Ag Method for producing a corrosion-protected flat steel product

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4071273A4 (en) * 2019-12-05 2022-10-19 Posco Steel sheet plated with al alloy and manufacturing method therefor

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US20100294400A1 (en) 2010-11-25
ATE535631T1 (en) 2011-12-15
WO2009047183A1 (en) 2009-04-16
EP2045360A1 (en) 2009-04-08

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