EP4392584A1 - Produit plat en acier laminé à froid et son procédé de production - Google Patents

Produit plat en acier laminé à froid et son procédé de production

Info

Publication number
EP4392584A1
EP4392584A1 EP22768283.8A EP22768283A EP4392584A1 EP 4392584 A1 EP4392584 A1 EP 4392584A1 EP 22768283 A EP22768283 A EP 22768283A EP 4392584 A1 EP4392584 A1 EP 4392584A1
Authority
EP
European Patent Office
Prior art keywords
cold
product
flat steel
rolled
steel product
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
EP22768283.8A
Other languages
German (de)
English (en)
Inventor
Dr. Ekaterina Bocharova
Dr. Frank HISKER
Dr. Nicholas WINZER
Dr. Alexander ZIMMERMANN
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.)
ThyssenKrupp Steel Europe AG
Original Assignee
ThyssenKrupp Steel Europe AG
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 ThyssenKrupp Steel Europe AG filed Critical ThyssenKrupp Steel Europe AG
Publication of EP4392584A1 publication Critical patent/EP4392584A1/fr
Pending legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • 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
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • C21D1/19—Hardening; Quenching with or without subsequent tempering by interrupted quenching
    • C21D1/20—Isothermal quenching, e.g. bainitic hardening
    • 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 of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties of ferrous metals or ferrous alloys 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
    • 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 of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0236—Cold rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0263—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0273—Final recrystallisation annealing
    • 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
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • 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
    • C23C2/04—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
    • C23C2/26—After-treatment
    • C23C2/28—Thermal after-treatment, e.g. treatment in oil bath
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/001—Austenite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/002—Bainite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite

Definitions

  • a cost effective weight reduction measure is the use of high strength steels. This enables the production of thin-walled components which, despite their low weight, can withstand high mechanical loads. So that the steels can also be formed into components with greater geometric complexity, these must also have greater ductility. Typically, the strength and ductility of steels are anti-correlated, i.e. the higher the strength, the lower the ductility. For this reason, the use of high-strength steels for such components is only possible to a limited extent.
  • DP steels typically consist largely of ferrite and martensite, but may also contain other phases such as bainite and/or residual austenite.
  • DP steels typically consist largely of ferrite and martensite, but may also contain other phases such as bainite and/or residual austenite.
  • the soft ferrite is usually deformed, while the hard martensite increases strength.
  • martensite can also be formed from optionally present retained austenite. This also contributes to the increase in strength without affecting the first stages of plastic deformation.
  • a disadvantage of DP steels relative to other high-strength steels is their high susceptibility to edge cracking, which can occur during the forming of stamped sheet metal.
  • edge crack sensitivity of a steel is evaluated with the so-called "hole expansion test”, in which a hole punched in a sheet metal sample is widened with a mandrel until the first crack appears, see ISO 16630:2017, "Metallic materials -- Sheet and strip -- Hole expanding test”. From the diameter of the hole before testing, D o , and when cracking first started, DR , the hole expansion ratio, X, is calculated using the following formula:
  • the object of the invention is therefore to provide a cold-rolled flat steel product with an optimized combination of high tensile strength R m , a low yield point R p0.2 and a high elongation at break A 80 , and to specify a corresponding method for its production.
  • a cold-rolled flat steel product which, in addition to Fe and unavoidable impurities in wt
  • the flat steel product according to the invention has a structure together with unavoidable structural components, which comprises the following phases (in %):
  • Martensite up to 20% (including 0).
  • the flat steel product according to the invention has a tensile strength R m determined according to DIN EN ISO 6892-1:2017 (specimen shape 2, longitudinal samples) of at least 780 MPa, a yield point R p o.2 of a maximum of 600 MPa and an elongation at break A 80 of at least 18%.
  • the Yield point R p0.2 can in particular be limited to a maximum of 580 MPa, preferably to a maximum of 550 MPa.
  • the minimum yield point is at least 440 MPa.
  • the lowest permissible hole expansion ratio X (in %) determined according to DIN EN ISO 16630:2017 can be calculated using the following formula:
  • the hole expansion ratio X -0.067 x Rm + A, where the constant A is at least 75%, in particular at least 78%, preferably at least 80%.
  • a time frame for the test is not specified in ISO 16630:2017. The values given here refer to tests carried out within 5 hours after punching the hole according to ISO 16630:2017.
  • the tensile strength R m is in particular a maximum of 920 MPa, preferably a maximum of 900 MPa.
  • a relatively high proportion of ferrite is required for a low yield strength R p0.2 .
  • the ferrite is preferentially deformed, while the harder, carbon-rich phases such as bainite, retained austenite and martensite serve as reinforcement.
  • the yield point is mainly influenced by the ferrite content. It has been found that for a yield point in the desired range there should be at least 20% by area, in particular at least 30% by area, preferably 40% by area.
  • a high proportion of martensite is generally associated with a low hole expansion ratio X, since the boundaries between adjacent ferrite grains and martensite packets serve as crack initiation points under external mechanical loads. A high density of potential crack initiation points has a negative effect on the sensitivity of the cut edges. For this reason, the proportion of martensite in the structure should be minimized as much as possible. Accordingly, the proportion of martensite is limited to a maximum of 20% by area, in particular to a maximum of 17% by area, preferably to a maximum of 13% by area, preferably to a maximum of 10% by area.
  • the martensite content can be 0.
  • the required mechanical properties can be achieved with a bainite content of between 10 and 70% by area. If the proportion of bainite is too low, the minimum requirements in terms of tensile strength R m and hole expansion ratio X are not met. For this reason, a bainite content of at least 10% by area, in particular at least 15% by area, preferably at least 20% by area. On the other hand, if the proportion of bainite is too high, the yield point R p0,2- is too high. For this reason, the proportion of bainite is limited to a maximum of 70% by area, in particular to a maximum of 60% by area, preferably to a maximum of 50% by area.
  • the relatively high elongation at break A 80 in relation to the tensile strength R m of the flat steel product according to the invention is mainly a consequence of the relatively high proportion of retained austenite in the structure. This has a positive effect on the elongation at break A 80 based on the strain-induced transformation of the retained austenite (ie the so-called TRI P effect) without influencing the first stages of plastic deformation (characterized by the yield point R p0.2 ).
  • a residual austenite content of at least 5%, in particular at least 6%, preferably at least 7%, is required.
  • the flat steel product according to the invention may contain a maximum of 15%, in particular a maximum of 13%, preferably a maximum of 12%.
  • Fine precipitations (carbides or carbonitrides) based on Nb can also be embedded in the microstructure. Due to their fineness, these cannot be detected using LOM, but can only be detected using transmission electron microscopy (TEM) at a magnification of 50,000 to 500,000 times.
  • Precipitations mean carbides or carbonitrides with a NaCl (Bl) crystal structure, which mainly consist of Nb and C.
  • the precipitates can also contain a small concentration of Ti, V, Mo, Cr, W or N.
  • Fine Nb-based precipitates promote a fine grain structure and can therefore have a positive effect on the mechanical properties and the hole expansion ratio.
  • the method according to the invention for producing a cold-rolled flat steel product with a ferritic matrix comprises the steps: a) Melting a steel consisting of Fe and unavoidable impurities (in % by weight) from
  • Nb 0.01 to 0.06%, with the following alloying elements from the group (P, S, N, Ti, V, Mo, B, Cu, W, Ni, Sn, As, Co, Zr, La, Ce, Nd, Pr, Ca, 0, H) and can be present with the following contents:
  • the pre-product is hot-rolled in one or more roll stands (hot rolling mill) with a final hot-rolling temperature of between 850 and 980 °C to form a hot-rolled flat steel product.
  • a final hot-rolling temperature for producing the hot-rolled flat steel product of at least 850° C., in particular at least 880° C. is chosen so that the deformation resistance does not increase too much. If the final hot rolling temperatures were too low, the rolling forces would increase disproportionately and the desired isotropy of the material would be lost due to the effects of thermomechanical rolling. In order to avoid undesirable coarse grain formation, the final rolling temperature for producing the hot-rolled flat steel product is limited to a maximum of 980 °C.
  • the cold-rolled steel flat product is held in a fourth stage of annealing at the final temperature coming out of the third stage equal to or higher than Ms and less than 455 °C for a period of 1 to 1000 s.
  • the setting of the temperature and time in the fourth stage is of crucial importance for the formation of a high proportion of bainite, which is necessary for achieving the required mechanical and technological properties of the end product.
  • Temperatures equal to or higher than Ms and less than 455 °C correspond to the range in which bainite is formed by the decomposition of austenite, provided that the austenite is obtained by adjusting the annealing temperature in the range between 840 and 900 °C and the duration between 30 and has been destabilized for 300 s.
  • the martensite start temperature Ms (in °C) is calculated from the C, Mn and Cr contents (each in % by weight) using the formula:
  • Copper (Cu) can separate out in the form of coarse particles, which have a negative effect on the mechanical properties.
  • Cu has a negative impact on castability.
  • the Cu content is limited to at most 0.1% by weight, particularly at most 0.05% by weight.
  • melts A - Y alloyed according to the compositions given in Table 1 were produced and cast to form slabs.
  • the melts not according to the invention and their contents of certain alloying elements, which deviate from the requirements of the invention, are underlined in Table 1. Contents of an alloying element that were so low that they were "0" in the technical sense, i.e. so low that they had no influence on the properties of the steel, are indicated in Table 1 by the entry.
  • Example A2 was produced with too low a VWO, but is otherwise the same as example A1.
  • the deviating VWO resulted in too low a proportion of bainite, too low a proportion of retained austenite and too high a proportion of undesirable microstructure components.
  • example A2 has too low a tensile strength R m , too low an elongation at break A 80 and too low a constant A.
  • Example A2 is therefore used here as a counter-example.
  • Steel A was also used in examples A3 - A6 to study the influence of the annealing temperature HT1. With the exception of HT1 (and consequently the average heating rate HR and the average cooling rate KR1), examples A3 to A6 are otherwise the same as example A1.
  • Too low HT1 as in example A3, resulted in too low a bainite content and too high a martensite content, hence very low X and too low a constant A.
  • too high HT1 as in example Example A6, too high a proportion of bainite and too low a proportion of ferrite, consequently too low R m and too high R p0.2 .
  • Examples Bl - El were produced with a low but allowable VWO and WET compared to those of example Al.
  • the examples Bl - El differed by their C content. This showed that the R m increases and the A 80 decreases with increasing C content. Both mechanical-mechanical-technological properties and structural characteristics were able to be achieved in the desired range with Examples CI and D1.
  • Steel B has too low a C content.
  • example Bl has an insufficient R m .
  • Steel E on the other hand, has too high a C content. This led to the formation of an excessively high proportion of undesirable structural components, consequently to an A 80 that was too low and a constant A that was too low in example E1.
  • Examples B1 and E1 therefore serve as counterexamples.
  • Examples C2 and C3 are comparable to Example CI but were made with even lower WET.
  • the WET was below the acceptable range. This led to a low A 80 and a constant A that is too low. C2 therefore serves as a counterexample.
  • the WET was very low but within acceptable limits. As a result, the mechanical-technological properties of the example were within the desired range.
  • Steels F - J differ primarily in their Mn content, but are otherwise comparable to steel A.
  • Examples F1 - J1 showed that the R m increases with increasing Mn content.
  • Examples Fl - Hl were also generated with a relatively low HT1.
  • Examples II - J1 were again created with a relatively high HT1.
  • the Mn content was below the required minimum content. This resulted in too low an Rm and too low a constant A.
  • sample J1 has too high a Mn content. This led to an excessive formation of martensite and retained austenite, which had a negative effect on the X and the A constant. Examples II and J1 therefore serve as counterexamples.
  • Examples F1 through J1 were also produced with a relatively low AKR.
  • the influence of ASR can be seen by comparing Examples II, 12 and 13.
  • Example 12 was produced with too low ASR but is otherwise the same as Example II.
  • Example 12 therefore serves as a counter-example.
  • Example 13 was produced with a very high AKR. However, this had not affected the mechanical-technological properties in any way.
  • Example NI has a very high Si content and a low Al content. These gave a relatively low X, but were within target range.
  • Example 01 is also one of the counter-examples with too high a Si content. In a similar way to Example LI, this resulted in too high a proportion of retained austenite, which adversely affected the X.
  • Examples N2-N4 are variations of example NI, with the duration or holding time HZ1 being varied. Too short HZ1 in counterexample N2 resulted in too high a proportion of martensite and too low a proportion of bainite, which resulted in a low X and consequently too low an A constant.
  • Example N3 had a longer HZ1 compared to example NI, but this had no significant effect on the structural characteristics and the mechanical-technological properties.
  • an excessively high HZ1 was set, which led to an excessively high proportion of bainite and an excessively low proportion of ferrite, and consequently to an R p0.2 that was too high.
  • Steels P to S have different Nb contents, but are otherwise comparable to steel A. These were processed in examples PI - S1 with a low HT2, a low DG and without a Zn-based anti-corrosion coating.
  • the comparison between Examples PI to S1 shows that the R m increases and the A 80 decreases with increasing Nb content.
  • Example PI has too low Nb content and consequently insufficient R m
  • example S1 has too high Nb content and consequently too low A 80 .
  • Examples PI and S1 therefore serve as counterexamples.
  • Example T5 is also similar to example TI, but was created with a KWG that was too high. This resulted in an A 80 that was too low and a constant A that was too low. Therefore, example T5 serves as a counterexample.
  • Steels W through Y differ in their levels of impurity elements V, Ti, Mo, Cu, Ni, P, S, N and B, but are otherwise comparable to steel A.
  • Steel W contains very low levels of impurity elements and was tested in Example W1 processed analogously to example Al.
  • the structural characteristics and the mechanical-technological properties of example W1 are comparable to those of example A1.
  • steel X has a higher but still acceptable concentration of impurity elements.
  • the resulting mechanical-technological properties, which were produced under the same process conditions, were worse than, for example, Al, but still within the target range.
  • Steel Y has too high a concentration of impurity elements.
  • Table 3 Process conditions of the exemplary embodiments with regard to the annealing and the optional hot-dip coating

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

Abstract

L'invention concerne un produit plat en acier laminé à froid présentant une résistance à la traction Rm d'au moins 780 MPa, un seuil d'écoulement RP0,2 d'au moins 440 MPa et inférieur à 600 MPa et un allongement à la rupture A80 d'au moins 18 %, ainsi qu'un procédé pour sa production.
EP22768283.8A 2021-08-25 2022-08-17 Produit plat en acier laminé à froid et son procédé de production Pending EP4392584A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102021121997.3A DE102021121997A1 (de) 2021-08-25 2021-08-25 Kaltgewalztes Stahlflachprodukt und Verfahren zu seiner Herstellung
PCT/EP2022/072977 WO2023025635A1 (fr) 2021-08-25 2022-08-17 Produit plat en acier laminé à froid et son procédé de production

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EP4392584A1 true EP4392584A1 (fr) 2024-07-03

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Country Link
EP (1) EP4392584A1 (fr)
CN (1) CN117957335A (fr)
DE (1) DE102021121997A1 (fr)
WO (1) WO2023025635A1 (fr)

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EP4627122A1 (fr) 2022-11-30 2025-10-08 ThyssenKrupp Steel Europe AG Produit plat en acier laminé à froid et son procédé de fabrication

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Publication number Priority date Publication date Assignee Title
JP5167487B2 (ja) 2008-02-19 2013-03-21 Ｊｆｅスチール株式会社 延性に優れる高強度鋼板およびその製造方法
CN103857808B (zh) 2011-09-13 2016-11-23 塔塔钢铁艾默伊登有限责任公司 高强度热浸镀锌钢带材
JP6310452B2 (ja) 2012-06-05 2018-04-11 ティッセンクルップ スチール ヨーロッパ アーゲーＴｈｙｓｓｅｎｋｒｕｐｐ Ｓｔｅｅｌ Ｅｕｒｏｐｅ Ａｇ 鋼、平鋼材及び平鋼材の製造方法
ES2614465T3 (es) * 2012-07-10 2017-05-31 Thyssenkrupp Steel Europe Ag Producto plano de acero laminado en frío y procedimiento para su fabricación
ES2625754T3 (es) 2013-03-11 2017-07-20 Tata Steel Ijmuiden Bv Fleje de acero de fase compleja galvanizado por inmersión en caliente de alta resistencia
US20140275516A1 (en) 2013-03-14 2014-09-18 Celanese Acetate Llc Naturally derived mixed cellulose esters and methods relating thereto
MX2018000329A (es) 2015-07-13 2018-03-14 Nippon Steel & Sumitomo Metal Corp Lamina de acero, lamina de acero galvanizado por inmersion en caliente, lamina de acero recocido y galvanizado y metodos de fabricacion.
JP2022520485A (ja) * 2019-02-18 2022-03-30 タタ、スティール、アイモイデン、ベスローテン、フェンノートシャップ 機械的特性が改善された高強度鋼
WO2020245626A1 (fr) * 2019-06-03 2020-12-10 Arcelormittal Tôle d'acier laminée à froid et revêtue et son procédé de fabrication

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