EP3827103A1 - Procédé pour la fabrication d'un produit en acier durci - Google Patents

Procédé pour la fabrication d'un produit en acier durci

Info

Publication number
EP3827103A1
EP3827103A1 EP19749593.0A EP19749593A EP3827103A1 EP 3827103 A1 EP3827103 A1 EP 3827103A1 EP 19749593 A EP19749593 A EP 19749593A EP 3827103 A1 EP3827103 A1 EP 3827103A1
Authority
EP
European Patent Office
Prior art keywords
thickness
coating
steel substrate
micrometers
less
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.)
Pending
Application number
EP19749593.0A
Other languages
German (de)
English (en)
Inventor
Stefan Pohl
Elisabeth Danger
Thorsten LABUDDE
Jürgen Butzkamm
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Muhr und Bender KG
Original Assignee
Muhr und Bender KG
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Muhr und Bender KG filed Critical Muhr und Bender KG
Publication of EP3827103A1 publication Critical patent/EP3827103A1/fr
Pending legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • C—CHEMISTRY; METALLURGY
    • 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
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/62—Quenching devices
    • C21D1/673—Quenching devices for die quenching
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/004—Heat treatment of ferrous alloys containing Cr and Ni
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/005—Heat treatment of ferrous alloys containing Mn
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/008—Heat treatment of ferrous alloys containing Si
    • 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
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
    • 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
    • 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
    • C23C2/26—After-treatment
    • 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
    • C23C2/26—After-treatment
    • C23C2/28—Thermal after-treatment, e.g. treatment in oil bath
    • 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
    • C23C2/26—After-treatment
    • C23C2/28—Thermal after-treatment, e.g. treatment in oil bath
    • C23C2/29—Cooling or quenching

Definitions

  • the invention relates to a method for producing coated hardened steel products, in particular for use as a structural component of a motor vehicle.
  • WO 2009/090555 A1 discloses a method for producing a hot-stamped coated steel section, comprising the steps of: pre-coating a steel strip with aluminum or aluminum alloy by hot dipping, the thickness of the precoating having 20 to 33 micrometers on each side, cutting the precoated steel strip into a steel section, heating the steel section in an oven, transferring the heated steel section into a press tool, hot stamping the steel section in the press tool, and cooling the steel section.
  • DE 10 2007 019 196 A1 discloses a method for producing flexibly rolled strip material with a cathodic corrosion protection layer.
  • the strip material is coated at a higher strip temperature in a zinc pot (hot dipped galvanized steel).
  • the zinc coating is in the same ratio rolled, like the actual strip thickness, whereby a final coating thickness after flexible rolling of greater than or equal to 7.5 micrometers is aimed for.
  • a method for producing a sheet metal component is known from WO 2008/1 13426 A2, a hot or cold strip being hot-dip coated or electrolytically coated and then subjected to a flexible rolling process.
  • a hot or cold strip being hot-dip coated or electrolytically coated and then subjected to a flexible rolling process.
  • different sheet pressures produce different sheet thicknesses of the flexibly rolled steel strip.
  • the coating is formed to be of different thicknesses during coating, the coating thickness being increased depending on the rolling pressure with increasing rolling pressure to be expected.
  • WO 2006 097 237 A1 discloses a method and a system for hot-dip coating hot-rolled steel strip.
  • the steel strip passes through a pickling station, a rinsing station, a drying station, a heating furnace and then a melting bath.
  • the finished thickness and the thickness tolerance of the hot-dip coated steel strip are achieved by controlled thickness reduction in a roll stand in the process line by checking the finished thickness in the outlet of the roll stand using a thickness measuring device and tracing deviations from the target thickness as a control signal to the position of the roll stand becomes.
  • WO 2016/198186 A1 discloses a method for hot forming a steel structure.
  • the steel component is provided with a corrosion-resistant scale protection layer and before hot forming there is a surface oxidation in which a corrosion-resistant oxidation layer is formed on the scale protection layer.
  • the present invention is based on the object of proposing a method for producing a coated and hardened component, in particular as a structural component for a motor vehicle, which has good corrosion protection resistance in areas with different thicknesses.
  • the object is achieved by means of a method for producing a hardened steel product with the steps: providing a steel substrate with a Base material made of hardenable steel; Coating the steel substrate with a pre-coating containing aluminum to produce a pre-coated steel substrate, the coating of the pre-coated steel substrate having a thickness (d1) of at least 34 micrometers (gm); Flexible rolling of the pre-coated steel substrate in such a way that successive sections of the pre-coated steel substrate are rolled out to different degrees to produce a variable thickness over the length of the pre-coated steel substrate, the pre-coating after the flexible rolling in thinner first sections being a reduced first Thickness (d2a) of less than 33 micrometers and in thicker second sections a reduced second thickness (d2b) which is thicker than the reduced first thickness (d2a); Working out a board from the flexibly rolled strip material; Heating the circuit board in such a way that the base material of the circuit board is at least partially austenitized, with the diffusion processes taking place
  • the substrate has a sufficiently thick coating even after flexible rolling. It has been shown that the coating increases during heating for the subsequent hot forming due to the diffusion processes, so that the final thickness of the coating after the hot forming is greater than the respective coating thickness after the flexible rolling and before the heating for the hot forming. Due to the fact that the precoating has a thickness of at least 34 micrometers, the coating is sufficiently thick to provide good protection against corrosion, even in the thinner first sections, due to the subsequent heating for hot forming, despite the reduction in thickness that results from flexible rolling to reach. In the thicker sections of the finished component, which generally have to withstand higher loads, the coating is also correspondingly thicker, so that these sections are particularly well protected.
  • the steel substrate can be, for example, a hardenable or temperable, in particular manganese-containing, steel material. In addition to manganese, this can contain further microalloying elements.
  • the steel material can contain, for example, the following proportions of alloy elements in percent by weight:
  • Manganese (Mn) with at least 0.5% and at most 5.0%, in particular at least 0.8% and at most 2.5%;
  • Silicon (Si) with at least 0.1% and at most 0.9%, in particular at most 0.5%;
  • Boron (B) with at least 0.0005 and at most 0.080%, in particular at least 0.002% and at most 0.006%;
  • Phosphorus (P) with at most 0.1%, in particular at most 0.01%;
  • alloying elements with a share of up to 1.55% (1550 ppm); the rest iron (Fe) and unavoidable impurities.
  • the substrate can in each case in percent by weight in particular at least one of:
  • Copper (Cu) with at most 0.1%
  • V Vanadium (V) with a maximum of 0.25%
  • the mass fraction of the optional alloying elements can also be lower, for example molybdenum can also be present at a maximum of 0.8%, 0.5% or 0.25%.
  • the mass fraction of the optional alloy elements is a maximum of 1.55%, in particular a maximum of 1.0%, in particular a maximum of 0.8%.
  • the alloy element niobium advantageously brings about a fine-grained structure of a component that is hot-formed from the alloy. In particular, in cooperation with molybdenum, which can inhibit grain growth, a particularly fine-grained structure results, which in turn has a favorable effect on the strength of the component produced therefrom.
  • Examples of usable steel materials containing boron manganese are 17MnB5, 20MnB5, 20MnB8, 22MnB5, 26MnB5 or 34MnB5.
  • the starting material can have a tensile strength of, for example, at least 450 MPa.
  • a molded part produced from the coated steel substrate can have a final tensile strength of, for example, at least 1 100 MPa, in particular at least 1500 MPa. It is also possible for certain sub-areas of the molded part, where necessary, to be set to a lower tensile strength of less than 1,100 MPa and therefore higher ductility.
  • the steel substrate can have an initial thickness of, for example, between 1.0 and 4.0 mm.
  • the coating preferably contains at least 85% by weight of aluminum, which also includes the possibility of using a pure aluminum coating (100% by weight of Al), as well as the use of an alloy which, as the main alloy component, contains aluminum with at least 85% by weight and optionally further Contains alloy components, for example silicon with, for example, between 5 and 15 percent by weight and / or iron with up to 5 percent by weight and / or one or more other alloying elements in smaller proportions.
  • alloy components for example silicon with, for example, between 5 and 15 percent by weight and / or iron with up to 5 percent by weight and / or one or more other alloying elements in smaller proportions.
  • the proportion of the other alloying elements for example at least one from the group of Mn, Cr, Ti, B, P, S, Cu, Ni, Nb, Mo, V, can together be, for example, up to 1.5% by weight.
  • the term aluminum coating or aluminum-based coating is generally used on the basis of the main constituent aluminum, with which the abovementioned possibilities of other alloy compositions are to be conceptually included.
  • the aluminum coating can, for example, be applied to the steel substrate in a hot-dip process in a melt bath with at least 85 percent by weight of aluminum and, if appropriate, other alloy components or other customary coating processes.
  • An exemplary composition of the molten bath or the applied coating can contain up to 3% by weight of iron, 9 to 12% by weight of silicon, optionally one or more contain further alloy elements with up to 1.5 percent by weight, and the rest of aluminum. It is understood that inevitable impurities may also be included.
  • the precoating is applied to the steel substrate with a thickness (d1) of at least 36 micrometers, in particular at least 40 micrometers.
  • the steel substrate pre-coated in this way forms the basis for a hardened component with variable thicknesses to be produced therefrom.
  • the coating of the steel substrate can be applied, for example, by means of hot-dip coating, the steel substrate being immersed in a basin with melted coating material. It is understood that other known coating methods can also be used.
  • the pre-coated steel substrate is rolled flexibly after the pre-coating, it being understood that further steps, such as heating, for unwinding, unwinding, straightening, cleaning or the like can be interposed.
  • the steel substrate is heated in the coating system after the application of the precoating in order to achieve pre-diffusion between the precoating and the steel substrate.
  • the pre-diffusion heating is carried out at temperatures below the melting temperature of the coating material, for example in a temperature window between 0.5 times and 0.9 times the melting temperature of the coating material.
  • a thicker interdiffusion zone is formed between the base material of the steel substrate and the coating material during the coating process. This makes it possible to carry out the heating more quickly in the course of hot forming, which has an overall favorable effect on the cycle times during hot forming.
  • strip material with a substantially uniform sheet thickness is rolled out by changing the roll gap during the process to form strip material with a variable sheet thickness over the length.
  • the sections of different thicknesses produced by the flexible rolling extend transversely to the longitudinal direction or direction of rolling of the strip material.
  • the strip material can be easily rewound into the coil and fed to further processing at another location, or it can be processed directly, for example by cutting the strip material to individual sheet metal elements.
  • Flexible rolling can be carried out with rolling degrees of at least 1% and / or a maximum of 60% based on the initial thickness (d1) of the precoated steel substrate, in particular with rolling degrees between 3% and 55%. Due to the flexible rolling, the thickness of the pre-coating is reduced accordingly with the steel substrate.
  • the precoating after the flexible rolling in thinner first sections can in particular have a reduced first thickness (d2a) of less than 20 micrometers.
  • the flexible rolling is carried out in such a way that the precoating after the flexible rolling in thicker second sections has a reduced second thickness (d2b) of more than 33 micrometers, in particular of more than 36 micrometers. It goes without saying that between the thinnest sections and the thickest sections of the strip material, depending on the desired component geometry, there may be any other thickness ranges or transition regions in between.
  • a process step downstream of the flexible rolling blanks are produced from the flexibly rolled strip material.
  • This process step is also called separating.
  • the separation can be carried out by mechanical cutting or by laser cutting.
  • the term circuit boards is intended to include both rectangular metal sheets that have been cut out of the strip material and shape cuts.
  • Shape cuts are sheet metal elements made from the strip material, the outer contour of which is already adapted to the shape of the end product.
  • the sheet metal blanks are hot-formed after the separation, it being possible for further process steps to be interposed if necessary.
  • the blank is at least in part at the austenitizing temperature heated; then placed in a thermoforming tool and formed in the thermoforming tool and cooled quickly, so that a hardened molded part is produced.
  • Heating to austenitizing temperature means a temperature range in which at least partial austenitizing takes place or is present, that is, a microstructure in the two-phase region of ferrite and austenite.
  • the board is heated to a temperature above Ac1, that is, the temperature at which austenite begins to form.
  • the board can be heated to a temperature of over 880 ° C and / or up to 960 ° C.
  • the circuit board is heated at least up to a temperature of 700 ° C. with a heating rate of more than 12 K / sec. The manufacturing time is reduced by rapid heating.
  • the board After heating to the austenitizing temperature and inserting it into the thermoforming tool, the board is formed and quickly cooled.
  • the rapid cooling of the molded part in the forming tool creates a hardened, at least partially martensitic structure in the component.
  • This process of hot forming and rapid cooling in a forming tool is also known as press hardening.
  • the first final thickness (d3a) is preferably formed in the thinner first sections of the finished component with more than 15 micrometers, in particular more than 20 micrometers, and less than 50 micrometers, in particular less than 40 micrometers.
  • the coating after the hot forming in the thicker second sections can have a second final thickness (d3b) of less than 60 micrometers, in particular less than 50 micrometers and / or more than 30 micrometers, in particular more than 35 micrometers exhibit.
  • the coating grows more strongly in the thinner areas in the course of hot forming than in thicker areas.
  • the coating with a final thickness ratio (d3a / d3b) of the first Final thickness (d3a) to the second final thickness (d3b) is formed, which is greater than an intermediate thickness ratio (d2a / d2b) of the reduced first thickness (d2a) to the reduced second thickness (d2b).
  • the different coating thicknesses in general adapt advantageously to one another, so that overall good protection against corrosion is achieved in all sections of the component.
  • the hot forming can be carried out as an indirect process, which comprises the sub-steps cold preforming, subsequent heating of the cold preformed component to austenitizing temperature and subsequent hot forming to produce the final contour of the product.
  • hot forming can also be carried out as a direct process, which is characterized in that the component is heated directly to the austenitizing temperature and then hot formed to the desired final contour in one step. A previous (cold) preforming does not take place here.
  • the coating can be produced in the forming tool in such a way that a metal oxide layer is formed on the surface.
  • a metal oxide layer is corrosion-resistant and inert, so tool wear during forming is reduced. If a metal oxide layer is formed on the coating surface, the present disclosure for the state after hot forming at given layer thicknesses relates to the total coating thickness, that is to say including the oxide layer. Preferred exemplary embodiments are explained below with reference to the drawing figures. Here shows
  • Figure 1 shows schematically an inventive method for producing a coated, hardened molded part
  • FIG. 2A shows a detail of the coated steel substrate after the precoating in an enlarged schematic representation
  • FIG. 2B shows a detail of the coated steel substrate after the flexible rolling in an enlarged schematic illustration
  • Figure 2C shows a detail of the coated and flexibly rolled steel substrate after hot forming in an enlarged schematic representation.
  • FIG. 1 shows a method according to the invention for securing a hardened product from a coated steel substrate 2.
  • the steel substrate is also referred to in strip form as a steel strip or generally as a strip material. When isolated, the steel substrate is also referred to as a circuit board.
  • the steel substrate 2 includes a hardenable flat steel product which, for example, can each contain the following proportions of alloy elements in percent by weight:
  • Manganese (Mn) with at least 0.5% and at most 5.0%, in particular at least 0.8% and at most 2.5%;
  • Silicon (Si) with at least 0.1% and at most 0.9%, in particular at most 0.5%;
  • Boron (B) with at least 0.0005 and at most 0.080%, in particular at least 0.002% and at most 0.006%;
  • Phosphorus (P) with at most 0.1%, in particular at most 0.01%;
  • This alloy composition includes, for example, boron-manganese-containing steel materials such as 17MnB5, 20MnB5, 20MnB8, 22MnB5, 26MnB5 and 34MnB5.
  • the steel material can have a yield strength of, for example, 150 to 1100 MPa and / or a tensile strength of at least 450 MPa.
  • the optional further alloy elements can be selected from the group: copper (Cu) with at most 0.1%;
  • V Vanadium (V) with a maximum of 0.25%
  • the percentages given refer in each case to the percentage by mass of the steel substrate.
  • One or more of the optional alloying elements mentioned can be used.
  • the mass fraction of the optional alloy elements is a maximum of 1.55%, in particular a maximum of 1.0%, preferably a maximum of 0.8%.
  • the steel substrate 2 which can be wound on a coil 3 in the initial state, is provided with a precoating 4.
  • the precoat 4 contains aluminum with at least 85 percent by weight and silicon with up to 15 percent by weight.
  • other alloying elements can be included at the expense of the silicon content, for example iron and / or other alloying elements with a total of up to 5 percent by weight.
  • the precoating 4 can be applied to the steel substrate 2 using generally known methods. One possibility is the hot dip application.
  • the steel substrate 2 passes through in a coating system 6 a molten bath 5 made of liquid coating material 4, which adheres to the surface of the substrate 2, so that a precoated steel substrate is produced.
  • the melt of the coating material can, for example, 8 to 15 weight percent silicon, 2 to 4 weight percent iron, optionally one or more further alloy elements, such as at least one from the group of Mn, Cr, Ti, B, P, S, Cu, Ni, Nb , Mo, V, of up to 1.5 percent by weight, and the remainder contain aluminum and unavoidable impurities.
  • the precoating 4 is applied to the steel substrate 2 with a thickness d1 of at least 36 micrometers, in particular at least 40 micrometers.
  • the coating thickness d1 can have a maximum thickness of 60 micrometers, in particular up to 50 micrometers in particular.
  • FIG. 2A schematically shows a section of the steel substrate 2 with precoating 4, the combination of steel substrate with precoating being provided with reference number 2 '.
  • the coated steel substrate 2 ' is rolled flexibly (S2).
  • the coated steel strip 2 ' which has a largely constant sheet thickness D1 over the length before the flexible rolling, is rolled by means of rollers 7, 8 in such a way that it receives a variable sheet thickness D2a, D2b, D2c along the rolling direction.
  • the coated and flexibly rolled steel substrate is provided with the reference number 12.
  • the process is monitored and controlled during rolling, the data determined by a sheet thickness measurement 9 being used as an input signal for controlling the rolls 7, 8.
  • the flexible rolling is carried out in accordance with the desired target thickness profile of a blank to be cut from the strip material 12 or a component to be produced therefrom.
  • the flexible rolling can be carried out with rolling degrees of at least 1% and / or a maximum of 60% based on the initial thickness D1 of the precoated steel substrate 2 ', in particular with rolling degrees between 3% and 55%.
  • FIG. 2B shows a section of the precoated steel substrate 12 after flexible rolling. It can be seen that the flexibly rolled strip material 12 after the rolling has more rolled out first areas a with a first thickness D2a and less rolled out second areas b with a second thickness D2b as well as intermediate areas c with variable thickness D2c. In the context of flexible rolling, there is a reduction in thickness both in the substrate 2 and accordingly in the precoating 4.
  • the precoating 4 has a reduced first thickness d2a of in particular less than 20 micrometers in the thinner first sections a, and a reduced second thickness d2b of in thicker second sections b in particular more than 33 micrometers, preferably more than 36 micrometers.
  • the strip material 12 can be rewound into the coil 3 so that it can be transported to a subsequent processing station.
  • the steel strip 12 can be smoothed in a subsequent process step, which takes place in a strip straightening device.
  • the smoothing step is optional and can also be omitted.
  • the coated and flexibly rolled steel strip 12 is separated in step S3.
  • Individual sheet metal blanks 22 are machined out of the steel strip 12, for example by means of a punching and / or cutting device 10. Depending on the shape of the sheet metal blanks 22 to be produced, they can be punched out of the strip material 12 as a shape cut, with an edge which is no longer used being eliminated as scrap , or the strip material 12 can simply be cut to pieces.
  • the blanks 22 are hot formed in a subsequent step S4, which can also be referred to as press hardening.
  • the plate 22 is heated to a temperature which is generally above the AC1 or AC3 temperature of the material, for example between 750 ° C. and 1000 ° C.
  • the heating can be carried out by suitable methods, such as for example by means of inductive heating, conductive heating, heating in the roller hearth furnace, contact heating by hot plates, infrared, or other known methods.
  • the board 22 is then placed in a thermoforming tool 11 and shaped therein and cooled or quenched so quickly that at least partially a martensitic hardness structure is produced in the molded part produced in this way.
  • hot forming can be carried out as a direct process.
  • the circuit board 22 is heated directly to the austenitizing temperature and then hot-worked in one step to the desired final contour. shaped.
  • a previous (cold) preforming does not take place here.
  • hot forming can also be carried out as an indirect process which comprises the sub-steps of cold preforming, subsequent heating of the cold preformed component to austenitizing temperature and subsequent hot forming to produce the final contour of the molded part.
  • the holding time for austenitizing the coated board 22 depends on the selected temperature and can be between 4 and 10 minutes.
  • the coating 4 of the hot-formed product 32 in the thinner first sections a preferably has a final coating thickness d3a of more than 15 micrometers, in particular more than 20 micrometers.
  • the coating 4 can have a second final thickness d3b, in particular of more than 30 micrometers, preferably more than 35 micrometers, after the heating or hot forming.
  • the final thickness d3a of the coating 4 is less than 50 micrometers, in particular less than 40 micrometers, in the thin regions a, and less than 60 micrometers, in particular less than 50, in the thicker regions b Micrometer.
  • a surface oxidation of the coated and flexibly rolled substrate 2 can be carried out before hot forming (S4).
  • An oxidation layer is formed on the coating 4. This leads to a higher heat absorption, so that the heating-up times can be shortened.
  • the blank can be heated at least up to a temperature of 700 ° C. with a heating rate of more than 12 K / sec in the course of hot forming.
  • thermoforming tool 10 cutting device 1 1 thermoforming tool 12 flexibly rolled substrate 22 circuit board

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Coating With Molten Metal (AREA)
  • Heat Treatment Of Articles (AREA)

Abstract

La présente invention concerne un procédé pour la fabrication d'un produit en acier durci comprenant les étapes suivantes consistant à : fournir un substrat d'acier (2) constitué d'acier durcissable ; recouvrir le substrat d'acier (2) d'une précouche en aluminium (4), la précouche (4) d'une épaisseur (d1) d'au moins 34 μm étant appliquée sur le substrat d'acier (2) ; réaliser un laminage flexible du substrat d'acier (2) préalablement revêtu afin d'obtenir une épaisseur variable sur la longueur du substrat d'acier (2) préalablement revêtu, la précouche étant laminée en premiers segments plus minces d'une première épaisseur réduite (d2a) inférieure à 33 μm et en seconds segments plus épais d'une seconde épaisseur réduite (d2b) qui est plus épaisse que la première épaisseur réduite (d2a) ; façonner un larget (22) à partir du substrat d'acier (2) ayant subi un laminage flexible ; chauffer le larget (22) à une température d'austénitisation, des processus de diffusion se produisant entre le matériau de base et la précouche (4) ; et thermoformer (S4) le larget (22) chauffé, le larget (22) chauffé étant mis en forme et ainsi rapidement refroidi de manière à fabriquer un produit en acier durci (42) comprenant un revêtement.
EP19749593.0A 2018-07-25 2019-07-10 Procédé pour la fabrication d'un produit en acier durci Pending EP3827103A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102018118015.2A DE102018118015A1 (de) 2018-07-25 2018-07-25 Verfahren zur Herstellung eines gehärteten Stahlprodukts
PCT/EP2019/068581 WO2020020644A1 (fr) 2018-07-25 2019-07-10 Procédé pour la fabrication d'un produit en acier durci

Publications (1)

Publication Number Publication Date
EP3827103A1 true EP3827103A1 (fr) 2021-06-02

Family

ID=67544154

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19749593.0A Pending EP3827103A1 (fr) 2018-07-25 2019-07-10 Procédé pour la fabrication d'un produit en acier durci

Country Status (5)

Country Link
US (1) US20210301364A1 (fr)
EP (1) EP3827103A1 (fr)
CN (1) CN112567054A (fr)
DE (1) DE102018118015A1 (fr)
WO (1) WO2020020644A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102020120580A1 (de) 2020-08-04 2022-02-10 Muhr Und Bender Kg Verfahren zum herstellen von beschichtetem stahlband, und verfahren zum herstellen eines gehärteten stahlprodukts
EP3964602A1 (fr) * 2020-09-02 2022-03-09 ThyssenKrupp Steel Europe AG Procédé de fabrication d'un composant en tôle par formage à chaud d'un produit en acier plat pourvu d'un revêtement de protection contre la corrosion

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005013103A1 (de) 2005-03-18 2006-09-28 Sms Demag Ag Kontrollierte Dickenreduktion bei schmelztauchbeschichtetem warmgewalztem Stahlband und hierbei eingesetzte Anlage
DE102005031461A1 (de) * 2005-07-04 2007-01-11 Bilstein Gmbh & Co. Kg Verfahren zur Herstellung eines mikrolegierten Kaltbandes mit einem auf den Dickenverlauf abgestimmten Eigenschaftsprofil
DE102007013739B3 (de) * 2007-03-22 2008-09-04 Voestalpine Stahl Gmbh Verfahren zum flexiblen Walzen von beschichteten Stahlbändern
DE102007019196A1 (de) * 2007-04-20 2008-10-23 Muhr Und Bender Kg Verfahren zum Erzeugen von flexibel gewalztem Bandmaterial mit einer kathodischen Korrosionsschutzschicht
EP2025771A1 (fr) * 2007-08-15 2009-02-18 Corus Staal BV Procédé de production de bande d'acier revêtu pour produire des éléments taylorisés adaptés à la mise en forme thermomécanique, bande produite, et utilisation d'une telle bande revêtue
WO2009090443A1 (fr) 2008-01-15 2009-07-23 Arcelormittal France Procédé pour fabriquer des produits estampés, et produits estampés préparés à l'aide de celui-ci
DE102009007909A1 (de) * 2009-02-06 2010-08-12 Thyssenkrupp Steel Europe Ag Verfahren zum Herstellen eines Stahlbauteils durch Warmformen und durch Warmformen hergestelltes Stahlbauteil
CN103492600B (zh) * 2011-04-27 2015-12-02 新日铁住金株式会社 热冲压部件用钢板及其制造方法
DE102012110972B3 (de) * 2012-11-14 2014-03-06 Muhr Und Bender Kg Verfahren zum Herstellen eines Erzeugnisses aus flexibel gewalztem Bandmaterial und Erzeugnis aus flexibel gewalztem Bandmaterial
KR101696069B1 (ko) * 2015-05-26 2017-01-13 주식회사 포스코 내박리성이 우수한 hpf 성형부재 및 그 제조방법
DE102015210459B4 (de) * 2015-06-08 2021-03-04 Volkswagen Aktiengesellschaft Verfahren zur Warmumformung eines Stahlbauteils
WO2017017485A1 (fr) * 2015-07-30 2017-02-02 Arcelormittal Procédé de fabrication d'une pièce phosphatable à partir d'une tôle d'acier revêtue d'un revêtement métallique à base d'aluminium
ES2659866T3 (es) * 2015-12-18 2018-03-19 Muhr Und Bender Kg Procedimiento e instalación para la fabricación de una pletina de chapa
DE102017127987A1 (de) * 2017-11-27 2019-05-29 Muhr Und Bender Kg Beschichtetes Stahlsubstrat und Verfahren zum Herstellen eines gehärteten Bauteils aus einem beschichteten Stahlsubstrat

Also Published As

Publication number Publication date
DE102018118015A1 (de) 2020-01-30
WO2020020644A1 (fr) 2020-01-30
US20210301364A1 (en) 2021-09-30
CN112567054A (zh) 2021-03-26

Similar Documents

Publication Publication Date Title
EP2733226B1 (fr) Procédé de fabrication d'un produit à partir d'un matériau de bande enroulé de façon flexible
EP2553133B1 (fr) Acier, produit plat en acier, élément en acier et procédé de fabrication d'un élément en acier
DE102008035714B9 (de) Stahlblech zum Warmpreßformen, das Niedrigtemperatur-Vergütungseigenschaft hat, Verfahren zum Herstellen desselben, Verfahren zum Herstellen von Teilen unter Verwendung desselben, und damit hergestellte Teile
EP3221484B1 (fr) Procédé de production d'une bande en acier polyphasé, durcissant à l'air, ayant une haute résistance et ayant d'excellentes propriétés de mise en oeuvre
DE102017127987A1 (de) Beschichtetes Stahlsubstrat und Verfahren zum Herstellen eines gehärteten Bauteils aus einem beschichteten Stahlsubstrat
EP2848709A1 (fr) Procédé de fabrication d'un composant en acier revêtu d'une coiffe métallique protégeant de la corrosion et composant en acier
WO2012085248A2 (fr) Procédé de formage et de durcissement de tôles d'acier revêtues
EP3250727B1 (fr) Pièce constituée de tôle d'acier revêtue à base d'aluminium durcie par moulage par compression et procédé de fabrication d'une telle pièce
EP3692178B1 (fr) Procede de fabrication d'une bande d'acier a partir d'un acier multiphase a tres haute resistance
EP3642371B1 (fr) Procédé de fabrication d'un composant en acier pourvu d'un revêtement métallique anticorrosion
EP3724359B1 (fr) Produit plat en acier laminé à chaud, à rigidité élevée, doté d'une résistance à la fissuration de bords élevée ainsi que d'une capacité de durcissement à la cuisson élevée et procédé de fabrication d'un tel produit plat en acier
EP3056591A1 (fr) Procede de fabrication d'un produit a partir d'un materiau de bande enroule
EP3877564B1 (fr) Élément structural trempé comprenant un substrat en acier et un revêtement anticorrosion, élément structural correspondant pour la réalisation de l'élément structural trempé ainsi que procédé de fabrication et utilisation
EP3827103A1 (fr) Procédé pour la fabrication d'un produit en acier durci
EP1865086B1 (fr) Utilisation d'un produit plat fabriqué à partir d'un acier au manganèse et au bore et procédé de sa fabrication
EP4192993A1 (fr) Procédé de production d'une bande d'acier revêtue, et procédé de production d'un produit d'acier trempé à partir de celle-ci
WO2022184811A1 (fr) Produit plat en acier, son procédé de production, et utilisation d'un tel produit plat en acier
EP4038215B1 (fr) Procédé de fabrication d'une pièce en tôle d'acier trempée à la presse présentant un revêtement à base d'aluminium, ébauche de tôle initiale et pièce en tôle d'acier trempée à la presse fabriquée à partir de celle-ci
WO2019242818A1 (fr) Composant de véhicule automobile composé d'un acier de traitement
WO2022106561A1 (fr) Matériau d'acier et son procédé de production
WO2024179867A1 (fr) Procédé de formage à la presse à chaud présentant des propriétés améliorées
DE102020113397A1 (de) Beschichtete Blechplatine zur Herstellung eines warmumgeformten und pressgehärteten Stahlblechbauteils
DE202024001189U1 (de) Riss-behaftetes durch Hot Stamping gebildetes Stahlteil mit einer dünnen Beschichtung ausgezeichneter Punktschweißbarkeit und ausgezeichneter Lackhaftung
WO2019011644A1 (fr) Procédé de fabrication d'un composant trempé à la presse

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20210203

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20230123