WO2022195024A1 - Bande, feuille ou ébauche d'acier et procédé de production d'une pièce formée à chaud ou d'une pièce préformée traitée à chaud - Google Patents

Bande, feuille ou ébauche d'acier et procédé de production d'une pièce formée à chaud ou d'une pièce préformée traitée à chaud Download PDF

Info

Publication number
WO2022195024A1
WO2022195024A1 PCT/EP2022/057019 EP2022057019W WO2022195024A1 WO 2022195024 A1 WO2022195024 A1 WO 2022195024A1 EP 2022057019 W EP2022057019 W EP 2022057019W WO 2022195024 A1 WO2022195024 A1 WO 2022195024A1
Authority
WO
WIPO (PCT)
Prior art keywords
steel
hot
formed part
blank
temperature
Prior art date
Application number
PCT/EP2022/057019
Other languages
English (en)
Inventor
Radhakanta RANA
Original Assignee
Tata Steel Ijmuiden B.V.
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 Tata Steel Ijmuiden B.V. filed Critical Tata Steel Ijmuiden B.V.
Priority to CN202280028300.3A priority Critical patent/CN117120636A/zh
Priority to EP22718071.8A priority patent/EP4308736A1/fr
Priority to KR1020237033887A priority patent/KR20230157997A/ko
Publication of WO2022195024A1 publication Critical patent/WO2022195024A1/fr

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/02Ferrous alloys, e.g. steel alloys containing silicon
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D1/00General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18Hardening; Quenching with or without subsequent tempering
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D1/00General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/62Quenching devices
    • C21D1/673Quenching devices for die quenching
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D8/00Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D8/00Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/04Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D9/00Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/0068Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for particular articles not mentioned below
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D9/00Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D9/00Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • C21D9/48Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals deep-drawing sheets
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/001Ferrous alloys, e.g. steel alloys containing N
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/04Ferrous alloys, e.g. steel alloys containing manganese
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/06Ferrous alloys, e.g. steel alloys containing aluminium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/12Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/20Ferrous alloys, e.g. steel alloys containing chromium with copper
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/22Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/24Ferrous alloys, e.g. steel alloys containing chromium with vanadium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/28Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/38Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
    • CCHEMISTRY; METALLURGY
    • C23COATING 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
    • C23CCOATING 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
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/02Pretreatment of the material to be coated, e.g. for coating on selected surface areas
    • CCHEMISTRY; METALLURGY
    • C23COATING 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
    • C23CCOATING 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
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/02Pretreatment of the material to be coated, e.g. for coating on selected surface areas
    • C23C2/022Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating
    • C23C2/0224Two or more thermal pretreatments
    • CCHEMISTRY; METALLURGY
    • C23COATING 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
    • C23CCOATING 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
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/02Pretreatment of the material to be coated, e.g. for coating on selected surface areas
    • C23C2/024Pretreatment of the material to be coated, e.g. for coating on selected surface areas by cleaning or etching
    • CCHEMISTRY; METALLURGY
    • C23COATING 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
    • C23CCOATING 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
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/04Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/06Zinc or cadmium or alloys based thereon
    • CCHEMISTRY; METALLURGY
    • C23COATING 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
    • C23CCOATING 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
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/04Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/12Aluminium or alloys based thereon
    • CCHEMISTRY; METALLURGY
    • C23COATING 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
    • C23CCOATING 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
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/26After-treatment
    • C23C2/28Thermal after-treatment, e.g. treatment in oil bath
    • CCHEMISTRY; METALLURGY
    • C23COATING 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
    • C23CCOATING 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
    • C23C30/00Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00Microstructure comprising significant phases
    • C21D2211/002Bainite
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00Microstructure comprising significant phases
    • C21D2211/005Ferrite
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00Microstructure comprising significant phases
    • C21D2211/008Martensite

Definitions

  • This invention relates to a steel strip, sheet or blank for producing a hot-formed part or a heat-treated pre-formed part, and to a method for hot-forming a steel blank or heat-treating a pre-formed part into an article and the use thereof.
  • the steel In cold-stamping or cold-forming processes, the steel is shaped into a product at near-room temperature.
  • Steel products produced in this way are for instance dual phase (DP) steels which have a ferritic-martensitic microstructure.
  • DP steels display a high ultimate tensile strength, their bendability and yield strength are low which is undesirable since these reduce crash performance in service.
  • Fracture toughness measurement is a useful tool to indicate the crash energy absorption of steels. When the fracture toughness parameters are high, generally a good crash behaviour is obtained. In view of the above, it will be clear that there is a need for steel parts that display an excellent ultimate tensile strength, and at the same time an excellent yield strength, bendability and fracture toughness, and in turn excellent crash energy absorption.
  • Alloying elements are elements that are deliberately added or allowed in the steel to provide a desirable effect. Boron and niobium are deemed not to provide a desirable effect in the steel according to the invention. Any boron or niobium that is present in the steel is to be qualified as inevitable impurities resulting from the Basic Oxygen Steelmaking (BOS) or the Electric Arc Furnace (EAF) process.
  • BOS Basic Oxygen Steelmaking
  • EAF Electric Arc Furnace
  • inevitable or unavoidable impurities mean that the low alloy steel does not contain any deliberately added elements other than those specified, and that the inevitable or unavoidable impurities are present only as a result of a technical or economical inability to remove them completely from the steel melt during the BOS- or EAF-process.
  • Carbon is added as the main strengthening element and also to promote hardenability.
  • C increases strength by distorting the cubic BCC lattice and converting it to a BCT lattice.
  • In bainite which is a mixture of ferrite and carbides, C strengthens the ferrite by solid solution hardening. According to the invention the carbon content is 0.07 to 0.20 wt.%.
  • Manganese and silicon are added also to increase the hardenability.
  • Mn causes solid solution hardening as well.
  • Mn below the limit will give insufficient hardenability and above the limit will make the steel difficult to process - as for example in terms of rolling, hot dip galvanising.
  • Si also causes solid solution strengthening.
  • the chromium content in the steel is at most 0.050 wt.%, and preferably it is present only as an inevitable impurity, i.e. it is not added as an alloying element.
  • the chromium content in the steel is at most 0.040 wt.%, and preferably is at most 0.020 wt.%. in some embodiment the chromium content in the steel is at most 0.010 wt.%.
  • the chromium content in the steel is lower than 0.0001 wt %, preferably there is no chromium present in the steel according to the invention.
  • the carbon content is at least 0.10 wt.%, preferably at least 0.12 wt.%.
  • the steel strip, sheet or blank is provided with a metallic coating layer such as a (commercially pure) aluminium layer or an aluminium alloy layer.
  • a typical metal bath for a hot dip coating such an aluminium layer comprises of aluminium alloyed with silicon e.g. aluminium alloyed with 8 to 11 wt.% of silicon and at most 4 wt.% of iron, optionally at most 0.2 wt.% of one or more additional elements such as calcium, unavoidable impurities, the remainder being aluminium.
  • Silicon is present in order to prevent the formation of a thick iron-intermetallic layer which reduces adherence and formability.
  • Iron is preferably present in amounts between 1 and 4 wt.%, more preferably at least 2 wt.%.
  • the hot-formed part or heat- treated pre-formed part produced from a steel strip, sheet or blank according to any one of the preceding claims, wherein the hot-formed part has a tensile strength of at least 700 MPa, preferably of at least 750 MPa.
  • a method for hot-forming a steel blank or heat-treating a pre-formed part into an article comprising the steps of:
  • Arl is the temperature at which the austenite to ferrite transformation completes during cooling of the steel and Mf is the martensite transformation finish temperature.
  • thermo-mechanical routes A, B or C which all benefit from the specific chemical composition designed in this invention.
  • the difference between the three different thermo-mechanical routes lies in the combination or separation of the mechanical and the thermal part of the thermo-mechanical route.
  • Route A heating a steel blank to achieve the austenite or austenite + ferrite state, deform it to its final shape while it is in the defined state (> Arl) and cool it to transform the austenite into the desired microstructure (direct hot-forming of the article), or
  • the method according to the invention includes a paint baking treatment, used after painting hot-formed component, for instance an additional ageing treatment at about 170-200°C for 20 minutes.
  • Example 1 As substrates the materials according to table 1 were used.
  • the inventive steel was cast and processed into cold-rolled strips with a gauge of 1.5 mm through reheating the cast steel to 1200°C, hot-rolling (Finish Rolling Temperature 900°C) to a final hot- rolled thickness of 4 mm. After finish rolling the steel was cooled on the run-out table at 25 °C/s to 700°C and simulated for coil cooling (i.e. coiling). After pickling the hot- rolled strips were cold-rolled to 1.5 mm.
  • the comparative steels of DP1000 and DP800 which are two cold-formable commercial steels, were also processed to the same condition (cold-rolled 1.5 mm gauge) and continuously annealed to achieve their mechanical properties as specified in the well-known industry specifications such as in VDA 239-100.
  • Table 1 Steel chemistry in wt.% (balance Fe and inevitable impurities).
  • Blanks of dimensions 220 mm x 110 mm x 1.5 mm, were prepared from the cold- rolled material and were subjected to reheating to 900°C (10°C below Ac3) and 940°C (30°C above Ac3) and were soaked for 5 min. in a nitrogen atmosphere to minimize surface degradation, transferred resulting in a temperature drop of 120°C in 10s and then subjected to cooling to about 160°C in the following rates: 30, 40, 50, 60, 80, 200°C/s. From the heat-treated samples, A50 tensile specimens along the rolling direction were prepared and tested with quasi-static strain rate (EN10002 standard). Microstructures were characterized from the RD-ND planes (RD and ND stand for rolling direction and normal direction respectively).
  • Table 3 shows that the ultimate tensile strength (UTS) greater than 700 MPa was achieved for all the cooling rates.
  • the yield strength (YS) increases with increasing cooling rate for both reheating temperatures since the amount of martensite increased in the microstructure with cooling rate.
  • Microstructures are either fully martensitic or a mixture of martensite, bainite and small amount of ferrite. High bending angles, greater than at least 115° at 1 mm thickness are also achieved as shown in Table 4 for both the specimen orientations.
  • the high performance of the invented steel in comparison with the available steels of similar strength is due to the higher bending angle and higher fracture toughness properties.
  • the component needs to fold, to be able to absorb energy without fracture, which is determined by its bendability.
  • the energy absorption capability before failure is determined by its fracture toughness parameters.
  • the improvements in these properties of the invented steel have been possible by virtue of the inventive steel chemistry design that provided the suitable microstructures, as defined in this invention, through the defined hot-forming processes.
  • Table 5 Tensile properties and bendability. hot pressed (900°C reheating with 200°C/s cooling rate) and baked.
  • Bending specimens (40 mm x 30 mm x 1.5 mm) from both parallel to rolling direction and perpendicular to rolling direction were prepared from each of the conditions and tested till fracture by three-point bending test according to the VDA 238-100 standard. These samples with bending axis parallel to the rolling direction are identified as longitudinal (L) bending specimens.
  • FIG. 3 Experimental details of the direct hot-forming experiments. Same temperature schedule is used for indirect hot-forming at a different timescale. Some critical temperatures, cooling rates, durations and process stages are indicated.
  • Figure 4 Graphical presentation of the mechanical property data in Table 3 after annealing at (a) 900 or (b) 940°C.
  • Left Y-axis - Open square tensile strength (Rm), open circles: yield strength (Rp);

Landscapes

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

Abstract

La présente invention concerne une bande, feuille ou ébauche d'acier pour produire des pièces formées à chaud ou une pièce préformée traitée à chaud, et un procédé de formage à chaud d'une ébauche d'acier ou de traitement à chaud d'une pièce préformée en un article et une utilisation associée, la bande, la feuille ou l'ébauche d'acier ayant la composition suivante, en % en poids : - C : de 0,07 à 0,20; - Mn : de 0,5 à 2,0; - Si : de 0,3 à 1,5; - Mo : de 0,1 à 1,0; et éventuellement un ou plusieurs des éléments choisis parmi : - Al : < 0,1; - Cr : au plus 0,050; - Cu : < 0,2; - N : < 0,01; - P : < 0,04; - S : < 0,025; - O : < 0.01; - Ti : < 0,10; - V : < 0,15; le reste étant du fer et des impuretés inévitables.
PCT/EP2022/057019 2021-03-17 2022-03-17 Bande, feuille ou ébauche d'acier et procédé de production d'une pièce formée à chaud ou d'une pièce préformée traitée à chaud WO2022195024A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
CN202280028300.3A CN117120636A (zh) 2021-03-17 2022-03-17 钢带材、片材或坯料以及用于生产热成形零件或热处理的预成形零件的方法
EP22718071.8A EP4308736A1 (fr) 2021-03-17 2022-03-17 Bande, feuille ou ébauche d'acier et procédé de production d'une pièce formée à chaud ou d'une pièce préformée traitée à chaud
KR1020237033887A KR20230157997A (ko) 2021-03-17 2022-03-17 열간-성형 부품 또는 열처리 사전성형 부품을 제조하는 방법과 강철 스트립, 시트 또는 블랭크

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP21163271 2021-03-17
EP21163271.6 2021-03-17

Publications (1)

Publication Number Publication Date
WO2022195024A1 true WO2022195024A1 (fr) 2022-09-22

Family

ID=74947259

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2022/057019 WO2022195024A1 (fr) 2021-03-17 2022-03-17 Bande, feuille ou ébauche d'acier et procédé de production d'une pièce formée à chaud ou d'une pièce préformée traitée à chaud

Country Status (4)

Country Link
EP (1) EP4308736A1 (fr)
KR (1) KR20230157997A (fr)
CN (1) CN117120636A (fr)
WO (1) WO2022195024A1 (fr)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1490535A (en) 1973-11-06 1977-11-02 Norrbottens Jaernverk Ab Manufacturing a hardened steel article
EP2708613A1 (fr) * 2011-05-13 2014-03-19 Nippon Steel & Sumitomo Metal Corporation Article moulé estampé à chaud et son procédé de production, élément d'absorption d'énergie et son procédé de production
EP2719786A1 (fr) * 2011-06-10 2014-04-16 Kabushiki Kaisha Kobe Seiko Sho Article moulé par pressage à chaud, procédé pour produire celui-ci, et tôle d'acier mince pour moulage à la presse à chaud
EP2728027A1 (fr) * 2011-06-30 2014-05-07 Hyundai Steel Company Acier thermodurci ayant une excellente résistance aux chocs et procédé de fabrication de pièces thermodurcissables au moyen dudit acier
EP2886674A1 (fr) * 2012-08-15 2015-06-24 Nippon Steel & Sumitomo Metal Corporation Tôle d'acier pour formage à chaud à la presse, son procédé de production, et élément de tôle d'acier pour formage à chaud à la presse
EP3235923A1 (fr) * 2014-12-19 2017-10-25 Baoshan Iron & Steel Co., Ltd. Acier à haute résistance, dont la limite d'élasticité est de 800 mpa et son procédé de production
WO2019223854A1 (fr) * 2018-05-22 2019-11-28 Thyssenkrupp Steel Europe Ag Pièce façonnée en tôle composée d'acier et présentant une résistance élevée à la traction, et procédé de fabrication de ladite pièce
EP3611288A1 (fr) * 2018-04-28 2020-02-19 Ironovation Materials Technology Co., Ltd. Composant estampé à chaud, plaque d'acier prérevêtue pour estampage à chaud et procédé d'estampage à chaud
WO2020239891A1 (fr) * 2019-05-28 2020-12-03 Tata Steel Ijmuiden B.V. Bande, tôle ou ébauche en acier pour la fabrication d'une pièce estampée à chaud, et procédé d'estampage à chaud d'une ébauche pour former une pièce

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1490535A (en) 1973-11-06 1977-11-02 Norrbottens Jaernverk Ab Manufacturing a hardened steel article
EP2708613A1 (fr) * 2011-05-13 2014-03-19 Nippon Steel & Sumitomo Metal Corporation Article moulé estampé à chaud et son procédé de production, élément d'absorption d'énergie et son procédé de production
EP2719786A1 (fr) * 2011-06-10 2014-04-16 Kabushiki Kaisha Kobe Seiko Sho Article moulé par pressage à chaud, procédé pour produire celui-ci, et tôle d'acier mince pour moulage à la presse à chaud
EP2728027A1 (fr) * 2011-06-30 2014-05-07 Hyundai Steel Company Acier thermodurci ayant une excellente résistance aux chocs et procédé de fabrication de pièces thermodurcissables au moyen dudit acier
EP2886674A1 (fr) * 2012-08-15 2015-06-24 Nippon Steel & Sumitomo Metal Corporation Tôle d'acier pour formage à chaud à la presse, son procédé de production, et élément de tôle d'acier pour formage à chaud à la presse
EP3235923A1 (fr) * 2014-12-19 2017-10-25 Baoshan Iron & Steel Co., Ltd. Acier à haute résistance, dont la limite d'élasticité est de 800 mpa et son procédé de production
EP3611288A1 (fr) * 2018-04-28 2020-02-19 Ironovation Materials Technology Co., Ltd. Composant estampé à chaud, plaque d'acier prérevêtue pour estampage à chaud et procédé d'estampage à chaud
WO2019223854A1 (fr) * 2018-05-22 2019-11-28 Thyssenkrupp Steel Europe Ag Pièce façonnée en tôle composée d'acier et présentant une résistance élevée à la traction, et procédé de fabrication de ladite pièce
WO2020239891A1 (fr) * 2019-05-28 2020-12-03 Tata Steel Ijmuiden B.V. Bande, tôle ou ébauche en acier pour la fabrication d'une pièce estampée à chaud, et procédé d'estampage à chaud d'une ébauche pour former une pièce

Also Published As

Publication number Publication date
EP4308736A1 (fr) 2024-01-24
KR20230157997A (ko) 2023-11-17
CN117120636A (zh) 2023-11-24

Similar Documents

Publication Publication Date Title
US20220282348A1 (en) Method for manufacturing a high strength steel product and steel product thereby obtained
US10995386B2 (en) Double annealed steel sheet having high mechanical strength and ductility characteristics, method of manufacture and use of such sheets
US20090071575A1 (en) Hot rolled dual phase steel sheet, and method of making the same
CN105849298A (zh) 具有优异的弯曲性能及超高强度的热压成型品用钢板、利用该钢板的热压成型品以及它们的制备方法
KR20190076258A (ko) 충돌특성 및 성형성이 고강도 강판 및 이의 제조방법
US20210147953A1 (en) Method for producing a high-strength steel strip with improved properties for further processing, and a steel strip of this type
ZA200505161B (en) Ultrahigh strength hot-rolled steel and method of producing bands
JP3587126B2 (ja) 延性に優れる高張力溶融亜鉛めっき鋼板およびその製造方法
KR20190052683A (ko) 망간 함유 평탄 강으로 이루어지는 평탄 강 제품을 제조하는 방법 및 이러한 평탄 강 제품
WO2020239891A1 (fr) Bande, tôle ou ébauche en acier pour la fabrication d&#39;une pièce estampée à chaud, et procédé d&#39;estampage à chaud d&#39;une ébauche pour former une pièce
JP7463408B2 (ja) 冷間圧延及び被覆された鋼板並びにその製造方法
KR20230016218A (ko) 열처리 냉연 강판 및 그 제조 방법
JP7326247B2 (ja) 熱間成形された部品を製造するための鋼ストリップ、シート又はブランク、部品、及びブランクを部品に熱間成形する方法
JP2024138480A (ja) 熱処理された冷間圧延鋼板及びその製造方法
WO2024104280A1 (fr) Composant de formage par estampage à chaud à haute ténacité et à faible teneur en carbone et feuille d&#39;acier
KR20230100737A (ko) 코팅 강판 및 고강도 프레스 경화 강 부품 및 그 제조 방법
JP4265152B2 (ja) 伸びおよび伸びフランジ性に優れた高張力冷延鋼板およびその製造方法
JP4265153B2 (ja) 伸びおよび伸びフランジ性に優れた高張力冷延鋼板およびその製造方法
JPH06145893A (ja) 延性と耐遅れ破壊特性に優れた高強度溶融亜鉛めっき鋼板およびその製造方法
WO2022195024A1 (fr) Bande, feuille ou ébauche d&#39;acier et procédé de production d&#39;une pièce formée à chaud ou d&#39;une pièce préformée traitée à chaud
JP4854924B2 (ja) プレス成形性に優れた高強度冷延鋼板およびその製造方法
CN110945148B (zh) 用于制备热成形零件的钢带材、片材或坯料,零件,和用于将坯料热成形为零件的方法
JP2004131754A (ja) 加工性と形状凍結性に優れた冷延鋼板及びその製造方法
JP2002317245A (ja) プレス加工性に優れた高強度溶融亜鉛めっき鋼板およびその製造方法
JP2004285435A (ja) 溶融亜鉛めっき鋼板およびその製造方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22718071

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 20237033887

Country of ref document: KR

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 1020237033887

Country of ref document: KR

WWE Wipo information: entry into national phase

Ref document number: 2022718071

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2022718071

Country of ref document: EP

Effective date: 20231017