US20100307644A1 - Process for manufacturing cold-rolled and annealed steel sheet with a very high strength, and sheet thus produced - Google Patents

Process for manufacturing cold-rolled and annealed steel sheet with a very high strength, and sheet thus produced Download PDF

Info

Publication number
US20100307644A1
US20100307644A1 US12/599,166 US59916608A US2010307644A1 US 20100307644 A1 US20100307644 A1 US 20100307644A1 US 59916608 A US59916608 A US 59916608A US 2010307644 A1 US2010307644 A1 US 2010307644A1
Authority
US
United States
Prior art keywords
steel
sheet
rolled
cold
composition
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.)
Abandoned
Application number
US12/599,166
Other languages
English (en)
Inventor
Javier Gil Otin
Antoine Moulin
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.)
ArcelorMittal France SA
Original Assignee
ArcelorMittal France SA
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
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=38596874&utm_source=***_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=US20100307644(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by ArcelorMittal France SA filed Critical ArcelorMittal France SA
Assigned to ARCELORMITTAL FRANCE reassignment ARCELORMITTAL FRANCE ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: GIL OTIN, JAVIER, MOULIN, ANTOINE
Publication of US20100307644A1 publication Critical patent/US20100307644A1/en
Priority to US15/243,610 priority Critical patent/US10612106B2/en
Abandoned legal-status Critical Current

Links

Images

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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/001—Continuous casting of metals, i.e. casting in indefinite lengths of specific 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
    • 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
    • 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
    • C21D8/0236—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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • 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
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • 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
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • 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
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing 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
    • C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium 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
    • C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium 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
    • C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium 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
    • C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium 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
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • 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
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
    • C23G1/08—Iron or steel

Definitions

  • the invention relates to the manufacture of thin cold-rolled and annealed steel sheet having a strength greater than 1200 MPa and an elongation at break greater than 8%.
  • the automotive sector and general industry particularly constitute fields of application of such steel sheet.
  • Dual-phase or TRIP steel sheets have been proposed with a maximum strength level of the order to 1000 MPa.
  • a maximum strength level of the order to 1000 MPa.
  • significantly higher strength levels for example 1200 ⁇ 1400 MPa, various difficulties arise:
  • multiphase steels having a predominantly bainitic structure have been developed.
  • multiphase steel sheet of moderate thickness is used to advantage for structural parts such as fender cross-members, pillars and various reinforcements.
  • patent EP 1 559 798 discloses the manufacture of steels having the composition: 0.10 ⁇ 0.25% C; 1.0 ⁇ 2.0% Si; and 1.5 ⁇ 3% Mn, the microstructure consisting of at least 60% bainitic ferrite and at least 5% residual austenite, the polygonal ferrite being less than 20%.
  • the exemplary embodiments presented in this document show that the strength does not exceed 1200 MPa.
  • Patent EP 1 589 126 also discloses the manufacture of thin cold-rolled sheet, the strength ⁇ elongation product of which is greater than 20000 MPa %.
  • the composition of the steels contains: 0.10 ⁇ 0.28% C; 1.0-2.0% Si; 1 ⁇ 3% Mn; and less than 0.10% Nb.
  • the structure consists of more than 50% bainitic ferrite, 5 to 20% residual austenite and less than 30% polygonal ferrite.
  • the embodiments presented show that the strength is still less than 1200 MPa.
  • the object of the present invention is to solve the abovementioned problems. Its aim is to provide a cold-rolled and annealed steel sheet having a strength greater than 1200 MPa together with an elongation at break greater than 8% and good cold formability. Another aim of the invention is to provide a steel that is largely insensitive to damage when being cut by a mechanical process.
  • the aim of the invention is to provide a process for manufacturing thin sheet in which slight variations of the parameters do not result in substantial modifications to the microstructure or the mechanical properties.
  • the aim of the invention is also to provide a steel sheet that can be easily manufactured by cold rolling, that is to say the hardness of which after the hot-rolling step is limited in such a way that the rolling forces remain modest during the cold-rolling step.
  • the aim of the invention is also to provide a thin steel sheet suitable for the optional deposition of a metal coating using standard processes.
  • the aim of the invention is also to provide a steel sheet that is largely insensitive to damage by cutting and is capable of hole expansion.
  • the aim of the invention is also to provide a steel exhibiting good weldability by means of standard assembly processes such as spot resistance welding.
  • one subject of the invention is a cold-rolled and annealed steel sheet with a strength greater than 1200 MPa, the composition of which comprises, the contents being expressed by weight: 0.10% ⁇ C ⁇ 0.25%, 1% ⁇ Mn ⁇ 3%, Al ⁇ 0.010%, Si ⁇ 2.990%, S ⁇ 0.015%, P ⁇ 0.1%, N ⁇ 0.008%, it being understood that 1% ⁇ Si+Al ⁇ 3%, the composition optionally comprising: 0.05% ⁇ V ⁇ 0.15%, B ⁇ 0.005%, Mo ⁇ 0.25%, Cr ⁇ 1.65%, it being understood that Cr+3Mo ⁇ 0.3%, Ti in an amount such that Ti/N ⁇ 4 and Ti ⁇ 0.040%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting, the microstructure of said steel comprising 15 to 90% bainite, the remainder consisting of martensite and residual austenite.
  • Yet another subject of the invention is a steel sheet of the above composition, with a strength greater than 1400 MPa and an elongation at break greater than 8%, characterized in that it contains: Mo ⁇ 0.25%, Cr ⁇ 1.65%, it being understood that Cr+3Mo ⁇ 0.3%, the microstructure of the steel comprising 45 to 65% bainite, the remainder consisting of islands of martensite and residual austenite.
  • Another subject of the invention is a steel sheet of the above composition, with a strength greater than 1600 MPa and an elongation at break greater than 8%, characterized in that it contains: Mo ⁇ 0.25%, Cr ⁇ 1.65%, it being understood that Cr+3Mo ⁇ 0.3%, the microstructure of the steel comprising 15 to 45% bainite, the remainder consisting of martensite and residual austenite.
  • the composition comprises: 0.19% ⁇ C ⁇ 0.23%
  • the composition comprises: 1.5% ⁇ Mn ⁇ 2.5%
  • the composition comprises: 1.2% ⁇ Si ⁇ 1.8%
  • the composition comprises: 1.2% ⁇ Al ⁇ 1.5%
  • the composition comprises 0.05% ⁇ V ⁇ 0.15% 0 . 004 ⁇ N ⁇ 0.008%.
  • the composition comprises: 0.12% ⁇ V ⁇ 0.15%
  • the composition comprises: 0.0005 ⁇ B ⁇ 0.003%.
  • the average size of the islands of martensite and residual austenite is less than 1 micron, the average distance between the islands being less than 6 microns.
  • a semifinished product is cast from this steel; then the semifinished product is brought to a temperature greater than 1150° C.
  • the semifinished product is hot-rolled so as to obtain a hot-rolled sheet.
  • the sheet is coiled and pickled; then the latter is cold-rolled with a reduction ratio of between 30 and 80% so as to obtain a cold-rolled sheet.
  • the cold-rolled sheet is reheated at a rate V c between 5 and 15° C./s up to a temperature T 1 between Ac3 and Ac3+20° C., and held there for a time t 1 between 50 and 150 s, then the sheet is cooled at a rate V R1 greater than 40° C./s but below 100° C./s down to a temperature T 2 between (M S ⁇ 30° C. and M S +30° C.).
  • the sheet is maintained at said temperature T 2 for a time t 2 between 150 and 350 s and then it is cooled at a rate V R2 of less than 30° C./s down to the ambient temperature.
  • Another subject of the invention is a process for manufacturing a cold-rolled steel sheet with a strength greater than 1200 MPa and an elongation at break greater than 8%, in which a steel is provided having a composition: 0.10% ⁇ C ⁇ 0.25%; 1% ⁇ Mn ⁇ 3%; Al ⁇ 0.010%; Si ⁇ 2.990%, it being understood that 1% ⁇ Si+Al ⁇ 3%; S ⁇ 0.015%; P ⁇ 0.1%; N ⁇ 0.008%; Mo ⁇ 0.25%; Cr ⁇ 1.65%, it being understood that Cr+3Mo ⁇ 0.3%, optionally 0.05% ⁇ V ⁇ 0.15%, B ⁇ 0.005% and Ti in an amount such that Ti/N ⁇ 4 and Ti ⁇ 0.040%.
  • a semifinished product is cast from this steel; then the semifinished product is brought to a temperature greater than 1150° C.; then the semifinished product is hot-rolled so as to obtain a hot-rolled sheet.
  • the sheet is coiled; then the latter is pickled; then the sheet is cold-rolled with a reduction ratio of between 30 and 80% so as to obtain a cold-rolled sheet.
  • the cold-rolled sheet is reheated at a rate V c between 5 and 15° C./s up to a temperature T 1 between Ac3 and Ac3+20° C., and held there for a time t 1 between 50 and 150 s, then the latter is cooled at a rate V R1 greater than 25° C./s but below 100° C./s down to a temperature T 2 between B S , and (M S ⁇ 20° C.).
  • the sheet is maintained at the temperature T 2 for a time t 2 between 150 and 350 s and then it is cooled at a rate V R2 of less than 30° C./s down to the ambient temperature.
  • the temperature T 1 is preferably between Ac3+10° C. and Ac3+20° C.
  • Another subject of the invention is the use of a cold-rolled and annealed steel sheet according to one of the above embodiments, or manufactured by a process according to one of the above embodiments, for the manufacture of structural parts or reinforcing elements in the automotive field.
  • FIG. 1 shows an example of the structure of a steel sheet according to the invention, the structure being revealed by the LePera etchant;
  • FIG. 2 shows an example of the structure of a steel sheet according to the invention, the structure being revealed by the Nital etchant.
  • the inventors have demonstrated that the above problems are solved when the cold-rolled and annealed thin steel sheet has a bainitic microstructure, complemented with islands of martensite and residual austenite, or “M-A” islands.
  • M-A martensite and residual austenite
  • carbon plays a very important role in the formation of the microstructure and in the mechanical properties: in conjunction with other elements (Cr, Mo, Mn) of the composition and with the annealing heat treatment after cold rolling, carbon increases the hardenability and makes it possible to obtain a bainitic transformation.
  • the carbon contents according to the invention also result in the formation of islands of martensite and residual austenite, the quantity, the morphology and the composition of which enable the above-mentioned properties to be obtained.
  • Carbon also retards the formation of proeutectoid ferrite after the annealing heat treatment following the cold rolling: otherwise, the presence of this low-hardness phase would result in excessively large amounts of local damage at the interface with the matrix, the hardness of which is higher. To achieve high strength levels, the presence of proeutectoid ferrite resulting from the annealing must therefore be avoided.
  • the carbon content is between 0.10 and 0.25% by weight. Below 0.10%, sufficient strength cannot be obtained and the stability of the residual austenite is unsatisfactory. Above 0.25%, the weldability is reduced because of the formation of quench microstructures in the heat-affected zone.
  • the carbon content is between 0.19 and 0.23%.
  • the weldability is very satisfactory and the quantity, the stability and the morphology of the M-A islands are particularly suitable for obtaining a favorable pair of mechanical properties, namely strength/elongation.
  • an addition of manganese which is an element promoting formation of the gamma-phase, prevents the formation of proeutectoid ferrite upon cooling after the annealing that follows the cold rolling.
  • Manganese also contributes to deoxidizing the steel during smelting in the liquid phase.
  • the addition of manganese also contributes to effective solid-solution hardening and to the achievement of a higher strength.
  • the manganese content is between 1.5 and 2.5% so that its effects are obtained, but without the risk of forming a deleterious banded structure.
  • An addition of silicon according to the invention therefore helps to stabilize a sufficient amount of residual austenite in the form of islands, which subsequently and progressively are transformed to martensite under the effect of a deformation. Another portion of the austenite is transformed directly to martensite upon cooling after annealing.
  • Aluminum is a very effective element for deoxidizing the steel. In this regard, its content is equal to or greater than 0.010%. Like silicon, it stabilizes the residual austenite.
  • the effects of aluminum and silicon on the stabilization of the austenite are similar.
  • the silicon and aluminum contents are such that 1% ⁇ Si+Al ⁇ 3%, satisfactory stabilization of the austenite is obtained, thereby making it possible to form the desired microstructures while still maintaining satisfactory usage properties.
  • the minimum aluminum content is 0.010%, the silicon content does not exceed 2.990%.
  • the silicon content is between 1.2 and 1.8% for stabilizing a sufficient amount of residual austenite and to prevent integranular oxidation during the hot-coiling step that precedes the cold rolling. In this way, the formation of highly adherent oxides is avoided, as is any appearance of surface defects that would result in particular in a lack of wettability in hot-dip galvanizing operations.
  • the aluminum content is preferably between 1.2 and 1.8%.
  • the effects of the aluminum are similar to those explained above in the case of silicon, but the risk of surface defects appearing is however less.
  • the steels according to the invention optionally contain molybdenum and/or chromium.
  • Molybdenum increases the hardenability, prevents the formation of proeutectoid ferrite and effectively refines the bainitic microstructure.
  • a content greater than 0.25% by weight increases the risk of forming a predominantly martensitic microstructure to the detriment of the formation of bainite.
  • Chromium also contributes to preventing the formation of proeutectoid ferrite and to the refinement of the bainitic microstructure. Above 1.65%, the risk of obtaining a predominantly martensitic structure is high.
  • the chromium and molybdenum contents are such that Cr+3Mo ⁇ 0.3%.
  • the chromium and molybdenum factors in this relationship reflect their influence on the hardenability, in particular the respective capability of these elements to prevent the formation of proeutectoid ferrite under the particular cooling conditions of the invention.
  • the steel may have very low or zero molybdenum and chromium contents, that is to say contents below 0.005% by weight for these two elements, and 0% boron.
  • the phosphorus content is limited to 0.1% so as to maintain a sufficient hot ductility.
  • the nitrogen content is limited to 0.008% so as to avoid any ageing.
  • the steel according to the invention optionally contains vanadium in an amount between 0.05 and 0.15%.
  • the nitrogen content is between 0.004 and 0.008%, precipitation of the vanadium in the form of fine carbonitrides may occur during the annealing that follows cold rolling, these carbonitrides providing additional hardening.
  • the vanadium content is between 0.12 and 0.15% by weight, the uniform elongation or the elongation at break is particularly increased.
  • the steel may optionally contain boron in an amount not exceeding 0.005%.
  • the steel preferably contains between 0.0005 and 0.003% boron, thereby helping to suppress the proeutectoid ferrite in the presence of chromium and/or molybdenum.
  • boron added in the amount mentioned above, makes it possible to obtain a strength greater than 1400 MPa.
  • the steel may optionally contain titanium in an amount such that Ti/N ⁇ 4 and Ti ⁇ 0.040%. This enables titanium carbonitrides to be formed and increases the hardening.
  • the balance of the composition consists of inevitable impurities resulting from the smelting.
  • the contents of these impurities, such as Sn, Sb and As, are less than 0.005%.
  • the microstructure of the steel is composed of 65 to 90% bainite, these contents referring to percentages per unit area, the remainder consisting of islands of martensite and residual austenite (islands of M-A compounds).
  • This structure is predominantly bainitic, containing no low-hardness proeutectoid ferrite, and has an elongation at break greater than 10%.
  • the M-A islands uniformly dispersed in the matrix have an average size of less than 1 micron.
  • FIG. 1 shows an example of the microstructure of a steel sheet according to the invention.
  • the morphology of the M-A islands was revealed by means of appropriate chemical etchants: after etching, the M-A islands appear as white on a relatively dark bainite matrix. Some of the small islands are localized between the bainitic ferrite laths. The islands are observed at magnifications ranging from about 500 ⁇ to 1500 ⁇ on a statistically representative area and the average size of the islands and the average distance between these islands are measured using image analysis software. In the case of FIG. 1 , the percentage of islands per unit area is 12% and the average size of the M-A islands is less than 1 micron.
  • the microstructure is composed of 45 to 65% bainite, the remainder consisting of islands of martensite and residual austenite.
  • the microstructure is composed of 15 to 45% bainite, the remainder consisting of martensite and residual austenite.
  • the casting may be carried out to form ingots or continuously to form slabs with a thickness of around 200 mm.
  • the casting may also be carried out to form thin slabs with a thickness of a few tens of millimeters, or to form thin strip between steel counter-rotating rolls.
  • the cast semifinished products are firstly heated to a temperature above 1150° C. so as to achieve, at all points, a temperature favorable for the high deformation that the steel undergoes during rolling.
  • the step of hot rolling these semifinished products starting at most at 1150° C. may be carried out directly after casting, so that an intermediate reheating step is in this case unnecessary;
  • the next step of the process depends on the chromium and molybdenum contents of the steel:
  • microstructural constituents measured by quantitative microscopy, namely fractions per unit area of bainite, martensite and residual austenite.
  • the M-A islands were revealed by the LePera etchant. Their morphology was examined using Scion® image analysis software.
  • the fracture energy at ⁇ 40° C. was determined on toughness specimens of the Charpy V type with a thickness reduced to 1.4 mm.
  • the damage associated with cutting (for example shearing or punching), which could possibly reduce the subsequent deformability of a cut part, was also evaluated.
  • the damage near the cut edges on specimens measuring 105 ⁇ 105 mm 2 having a hole with an initial diameter of 10 mm was also evaluated.
  • the relative increase in the diameter of the hole after introducing a conical punch was measured until cracking occurred.
  • the sheets of composition according to the invention and manufactured according to the conditions of the invention have a particularly advantageous combination of mechanical properties: on the one hand, a strength greater than 1200 MPa and, on the other hand, an elongation at break always greater than or equal to 10%.
  • the steels according to the invention also have a Charpy V fraction energy at ⁇ 40° C. of greater than 40 joules/cm 2 . This allows the manufacture of parts that are resistant to the sudden propagation of a fault, especially in the case of dynamic stressing.
  • the microstructures of the steels with a minimum strength of 1200 MPa and a minimum elongation at break of 10% according to the invention have a bainite content between 65 and 90%, the remainder consisting of M-A islands.
  • FIG. 1 thus shows the microstructure of the steel sheet 13 a comprising 88% bainite and 12% M-A islands, this micro-structure being revealed by etching with the LePera etchant.
  • FIG. 2 shows this microstructure revealed by a Nital etchant.
  • the steels according to the invention have a bainite content of between 45 and 65%, the remainder being M-A islands.
  • the steels according to the invention have a bainite content of between 15 and 35%, the remainder being martensite and residual austenite.
  • the steel sheets according to the invention have an M-A island size of less than 1 micron, the inter-island distance being less than 6 microns.
  • the steels according to the invention also have good resistance to damage in the case of cutting, since the damage factor ⁇ is limited to ⁇ 23%.
  • a steel sheet (R5) not having these features may have a damage factor of 43%.
  • the sheets according to the invention exhibit good hole expansion capability.
  • the steels according to the invention also have good homogeneous weldability: for welding parameters suitable for the thicknesses indicated above, the welded joints are free of cold or hot cracks.
  • the steel sheets I1-b and I1-c were annealed at too low a temperature T 1 , the austenitic transformation not being complete. Consequently, the microstructure includes proeutectoid ferrite (40% in the case of I1b and 20% in the case of I1-c) and an excessive content of M-A islands. The strength is therefore reduced by the presence of proeutectoid ferrite.
  • the soak temperature T 2 is above M S +30° C.: the bainitic transformation that occurs at a higher temperature gives rise to a coarser structure and results in an insufficient strength.
  • the soak temperature T 2 is below M S ⁇ 20° C. Consequently, the cooling rate V R1 causes the appearance of bainite formed at low temperature and of martensite, these being associated with an insufficient elongation.
  • Steel R1 has an insufficient (silicon+aluminum) content and the soak temperature T 2 is below M S ⁇ 20° C. Because of the insufficient (Si+Al) content, the quantity of M-A islands formed is insufficient to obtain a strength equal to or greater than 1200 MPa.
  • Steels R2 and R3 have insufficient carbon, manganese and silicon+aluminum contents.
  • the amount of M-A compounds formed is less than 10%.
  • the annealing temperature T 1 below Ac3 results in an excessive content of both proeutectoid ferrite and cementite, and leads to an insufficient strength.
  • Steel R4 has an insufficient (Si+Al) content and the cooling rate V R1 is in particular too low.
  • the enrichment of the austenite with carbon upon cooling is therefore insufficient to allow the formation of martensite and to obtain the strength and elongation properties intended by the invention.
  • Steel R5 also has an insufficient (Si+Al) content.
  • the insufficiently rapid cooling rate after annealing results in an excessive content of proeutectoid ferrite and to an insufficient mechanical strength.
  • a steel sheet I2-d was manufactured according to a process having identical characteristics, with the exception of the temperature T 1 , which was 830° C., i.e. the temperature Ac3. In the case in which T 1 is equal to Ac3, the capability of conical hole expansion is 25%. When the temperature T 1 is equal to 850° C.
  • the invention allows the manufacture of steel sheets that combine very high strength with high ductility.
  • the steel sheets according to the invention are used to advantage for the manufacture of structural parts or reinforcing elements in the automotive and general industry fields.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Laminated Bodies (AREA)
US12/599,166 2007-05-11 2008-04-28 Process for manufacturing cold-rolled and annealed steel sheet with a very high strength, and sheet thus produced Abandoned US20100307644A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US15/243,610 US10612106B2 (en) 2007-05-11 2016-08-22 Process for manufacturing cold-rolled and annealed steel sheet with a very high strength, and sheet thus produced

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR07290598.7 2007-05-11
EP07290598A EP1990431A1 (fr) 2007-05-11 2007-05-11 Procédé de fabrication de tôles d'acier laminées à froid et recuites à très haute résistance, et tôles ainsi produites
PCT/FR2008/000609 WO2008145871A2 (fr) 2007-05-11 2008-04-28 Procede de fabrication de tôles d'acier laminees a froid et recuites a tres haute resistance, et tôles ainsi produites

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/FR2008/000609 A-371-Of-International WO2008145871A2 (fr) 2007-05-11 2008-04-28 Procede de fabrication de tôles d'acier laminees a froid et recuites a tres haute resistance, et tôles ainsi produites

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US15/243,610 Continuation US10612106B2 (en) 2007-05-11 2016-08-22 Process for manufacturing cold-rolled and annealed steel sheet with a very high strength, and sheet thus produced

Publications (1)

Publication Number Publication Date
US20100307644A1 true US20100307644A1 (en) 2010-12-09

Family

ID=38596874

Family Applications (4)

Application Number Title Priority Date Filing Date
US12/599,166 Abandoned US20100307644A1 (en) 2007-05-11 2008-04-28 Process for manufacturing cold-rolled and annealed steel sheet with a very high strength, and sheet thus produced
US15/243,610 Active 2029-06-03 US10612106B2 (en) 2007-05-11 2016-08-22 Process for manufacturing cold-rolled and annealed steel sheet with a very high strength, and sheet thus produced
US16/592,341 Active 2028-07-26 US11414722B2 (en) 2007-05-11 2019-10-03 Process for manufacturing cold-rolled and annealed steel sheet with a very high strength, and sheet thus produced
US17/575,300 Pending US20220136078A1 (en) 2007-05-11 2022-01-13 Process for manufacturing cold-rolled and annealed steel sheet with a very high strength, and sheet thus produced

Family Applications After (3)

Application Number Title Priority Date Filing Date
US15/243,610 Active 2029-06-03 US10612106B2 (en) 2007-05-11 2016-08-22 Process for manufacturing cold-rolled and annealed steel sheet with a very high strength, and sheet thus produced
US16/592,341 Active 2028-07-26 US11414722B2 (en) 2007-05-11 2019-10-03 Process for manufacturing cold-rolled and annealed steel sheet with a very high strength, and sheet thus produced
US17/575,300 Pending US20220136078A1 (en) 2007-05-11 2022-01-13 Process for manufacturing cold-rolled and annealed steel sheet with a very high strength, and sheet thus produced

Country Status (16)

Country Link
US (4) US20100307644A1 (fr)
EP (2) EP1990431A1 (fr)
JP (1) JP5398701B2 (fr)
KR (1) KR101523395B1 (fr)
CN (1) CN101765668B (fr)
AR (1) AR066508A1 (fr)
BR (1) BRPI0821572B1 (fr)
CA (1) CA2686940C (fr)
ES (1) ES2655476T5 (fr)
HU (1) HUE035549T2 (fr)
MA (1) MA31555B1 (fr)
MX (1) MX2009011927A (fr)
PL (1) PL2155915T5 (fr)
RU (1) RU2437945C2 (fr)
WO (1) WO2008145871A2 (fr)
ZA (1) ZA200907430B (fr)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110168300A1 (en) * 2008-05-21 2011-07-14 Arcelormittal Investigacion Y Desarrollo Sl Manufacturing method for very high-strength cold-rolled dual-phase steel sheets and sheets so produced
WO2012153016A1 (fr) * 2011-05-10 2012-11-15 Arcelormittal Investigación Y Desarrollo Sl Tôle d'acier a hautes caracteristiques mecaniques de resistance, de ductilite et de formabilite, procede de fabrication et utilisation de telles tôles
EP2690184A1 (fr) * 2012-07-27 2014-01-29 ThyssenKrupp Steel Europe AG Cold rolled steel flat product and method for its production
CN104018069A (zh) * 2014-06-16 2014-09-03 武汉科技大学 一种高性能低碳含Mo贝氏体钢及其制备方法
US9611524B2 (en) 2012-03-30 2017-04-04 Kobe Steel, Ltd. High-yield-ratio high-strength steel sheet having excellent workability
EP2730671B1 (fr) 2011-07-06 2017-11-01 Nippon Steel & Sumitomo Metal Corporation Feuille d'acier laminée à froid, plaquée par immersion à chaud, et son procédé de fabrication
EP3150736A4 (fr) * 2014-05-29 2018-01-31 Nippon Steel & Sumitomo Metal Corporation Matériau d'acier traité à chaud et procédé pour le produire
US20180044774A1 (en) * 2015-02-19 2018-02-15 Arcelormittal Method of producing a phosphatable part from a sheet coated with an aluminum-based coating and a zinc coating
US10301700B2 (en) 2013-08-22 2019-05-28 Thyssenkrupp Steel Europe Ag Method for producing a steel component
US10358708B2 (en) * 2012-03-29 2019-07-23 Jfe Steel Corporation High strength steel plate having low yield ratio excellent in terms of strain ageing resistance, method of manufacturing the same and high strength welded steel pipe made of the same
US10907232B2 (en) 2014-07-03 2021-02-02 Arcelormittal Method for producing a high strength coated steel sheet having improved strength, formability and obtained sheet
US10941476B2 (en) 2016-01-22 2021-03-09 Jfe Steel Corporation High strength steel sheet and method for producing the same
US10954580B2 (en) 2015-12-21 2021-03-23 Arcelormittal Method for producing a high strength steel sheet having improved strength and formability, and obtained high strength steel sheet
US11530461B2 (en) 2017-12-05 2022-12-20 Arcelormittal Cold rolled and annealed steel sheet and method of manufacturing the same
US11655516B2 (en) 2016-12-21 2023-05-23 Arcelormittal Tempered and coated steel sheet having excellent formability and a method of manufacturing the same

Families Citing this family (37)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1990431A1 (fr) * 2007-05-11 2008-11-12 ArcelorMittal France Procédé de fabrication de tôles d'acier laminées à froid et recuites à très haute résistance, et tôles ainsi produites
CN101928875A (zh) * 2009-06-22 2010-12-29 鞍钢股份有限公司 具有良好成形性能的高强度冷轧钢板及其制备方法
JP5703608B2 (ja) * 2009-07-30 2015-04-22 Ｊｆｅスチール株式会社 高強度鋼板およびその製造方法
EP2627790B1 (fr) * 2010-10-12 2014-10-08 Tata Steel IJmuiden BV Methode pour deformation a chaud d' une tole d'acier et tole d'acier
US9115416B2 (en) 2011-12-19 2015-08-25 Kobe Steel, Ltd. High-yield-ratio and high-strength steel sheet excellent in workability
BR112014017042B1 (pt) * 2012-01-13 2020-10-27 Nippon Steel Corporation chapa de aço laminada a frio e processo de fabricação da mesma
JP5382278B1 (ja) 2012-01-13 2014-01-08 新日鐵住金株式会社 ホットスタンプ成形体及びその製造方法
JP2013209728A (ja) * 2012-03-30 2013-10-10 Jfe Steel Corp 耐時効性に優れた冷延鋼板およびその製造方法
EP2837707B1 (fr) * 2012-04-10 2018-06-13 Nippon Steel & Sumitomo Metal Corporation Élément d'absorption d'impact, et son procédé de fabrication
JP2014019928A (ja) * 2012-07-20 2014-02-03 Jfe Steel Corp 高強度冷延鋼板および高強度冷延鋼板の製造方法
CN102766807A (zh) * 2012-07-31 2012-11-07 内蒙古包钢钢联股份有限公司 一种含硼贝氏体钢板及其制造方法
PE20151042A1 (es) * 2012-09-14 2015-07-27 Salzgitter Mannesmann Prec Gmbh Aleacion de acero para un acero de alta resistencia, de baja aleacion
WO2015011511A1 (fr) 2013-07-24 2015-01-29 Arcelormittal Investigación Y Desarrollo Sl Tôle d'acier à très hautes caractéristiques mécaniques de résistance et de ductilité, procédé de fabrication et utilisation de telles tôles
DE102013013067A1 (de) * 2013-07-30 2015-02-05 Salzgitter Flachstahl Gmbh Siliziumhaltiger, mikrolegierter hochfester Mehrphasenstahl mit einer Mindestzugfestigkeit von 750 MPa und verbesserten Eigenschaften und Verfahren zur Herstellung eines Bandes aus diesem Stahl
PL3114246T3 (pl) * 2014-02-05 2020-03-31 Arcelormittal S.A. Formowalna na gorąco, możliwa do hartowania na powietrzu, spawalna, blacha stalowa
CN103952635B (zh) * 2014-05-13 2016-09-14 东北特钢集团北满特殊钢有限责任公司 含锰硅的高强钢及其制备方法
WO2016001702A1 (fr) 2014-07-03 2016-01-07 Arcelormittal Procédé de fabrication d'une tôle d'acier revêtue à haute résistance présentant une résistance, une ductilité et une formabilité améliorées
WO2016001704A1 (fr) 2014-07-03 2016-01-07 Arcelormittal Procédé de fabrication d'une tôle d'acier à haute résistance et tôle ainsi obtenue
WO2016001710A1 (fr) 2014-07-03 2016-01-07 Arcelormittal Procédé de fabrication d'un acier revêtu à haute résistance ayant une résistance et une ductilité améliorée et tôle obtenue
WO2016001700A1 (fr) 2014-07-03 2016-01-07 Arcelormittal Procédé de production d'une tôle d'acier à haute résistance présentant une résistance, une ductilité et une aptitude au formage améliorées
WO2016001706A1 (fr) 2014-07-03 2016-01-07 Arcelormittal Procédé de fabrication d'une tôle d'acier haute résistance ayant une résistance et une aptitude au formage améliorées et feuille ainsi obtenue
DE102014017274A1 (de) 2014-11-18 2016-05-19 Salzgitter Flachstahl Gmbh Höchstfester lufthärtender Mehrphasenstahl mit hervorragenden Verarbeitungseigenschaften und Verfahren zur Herstellung eines Bandes aus diesem Stahl
DE102015112886A1 (de) * 2015-08-05 2017-02-09 Salzgitter Flachstahl Gmbh Hochfester aluminiumhaltiger Manganstahl, ein Verfahren zur Herstellung eines Stahlflachprodukts aus diesem Stahl und hiernach hergestelltes Stahlflachprodukt
WO2018115933A1 (fr) 2016-12-21 2018-06-28 Arcelormittal Tôle d'acier laminée à froid à haute résistance présentant une formabilité élevée et son procédé de fabrication
WO2018115935A1 (fr) * 2016-12-21 2018-06-28 Arcelormittal Tôle d'acier revêtue et revenue présentant une excellente formabilité et son procédé de fabrication
WO2018215813A1 (fr) * 2017-05-22 2018-11-29 Arcelormittal Procédé de fabrication d'une pièce en acier et pièce en acier correspondante
WO2018220430A1 (fr) * 2017-06-02 2018-12-06 Arcelormittal Tôle d'acier destinée à la fabrication de pièces trempées à la presse, pièce trempée à la presse présentant une association de résistance élevée et de ductilité d'impact, et procédés de fabrication de cette dernière
WO2018234839A1 (fr) 2017-06-20 2018-12-27 Arcelormittal Tôle d'acier revêtue de zinc présentant une soudabilité par points de haute résistance
WO2019122963A1 (fr) * 2017-12-19 2019-06-27 Arcelormittal Tôle d'acier laminée à froid et traitée thermiquement et son procédé de fabrication
CN109576579A (zh) * 2018-11-29 2019-04-05 宝山钢铁股份有限公司 一种具有高扩孔率和较高延伸率的980MPa级冷轧钢板及其制造方法
KR102544854B1 (ko) * 2018-11-30 2023-06-19 아르셀러미탈 구멍 확장비가 높은 냉연 어닐링된 강판 및 그 제조 방법
CN109894812B (zh) * 2019-02-13 2021-09-24 舞阳钢铁有限责任公司 一种小单重坯料生产Cr-Mo钢板的方法
CN112159931B (zh) * 2020-09-28 2022-08-12 首钢集团有限公司 一种具有连续屈服的1000MPa级中锰TRIP钢及其制备方法
CN113215493B (zh) * 2021-05-11 2022-01-07 北京理工大学 一种高强度榴弹弹钢及其制备方法
CN114807746B (zh) * 2021-05-28 2022-12-30 广西柳钢华创科技研发有限公司 高速棒材生产的hrb500e螺纹钢筋
CN113699456B (zh) * 2021-09-01 2022-06-21 山东盛阳金属科技股份有限公司 一种254SMo超级奥氏体不锈钢热连轧板卷生产工艺
CN115261704B (zh) * 2022-07-29 2023-01-24 攀钢集团攀枝花钢铁研究院有限公司 中等强度热轧贝氏体钢轨制造方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060137768A1 (en) * 2004-12-28 2006-06-29 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High strength thin steel sheet having high hydrogen embrittlement resisting property
US20060144483A1 (en) * 2002-11-19 2006-07-06 Jean Beguinot Method for making an abrasion-resistant steel plate and plate obtained

Family Cites Families (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04350121A (ja) * 1991-05-27 1992-12-04 Nippon Steel Corp 高温強度特性がすぐれた鋼板の製造方法
FR2729974B1 (fr) 1995-01-31 1997-02-28 Creusot Loire Acier a haute ductilite, procede de fabrication et utilisation
JPH0925538A (ja) * 1995-05-10 1997-01-28 Kobe Steel Ltd 耐孔明き腐食性および圧壊特性に優れた高強度冷延鋼板、および高強度亜鉛系めっき鋼板並びにそれらの製造方法
JPH09263838A (ja) * 1996-03-28 1997-10-07 Kobe Steel Ltd 伸びフランジ性に優れた高強度冷延鋼板の製造方法
JP3450985B2 (ja) * 1997-04-10 2003-09-29 新日本製鐵株式会社 形状が良好で曲げ性に優れた高強度冷延鋼板とその製造方法
US6254698B1 (en) 1997-12-19 2001-07-03 Exxonmobile Upstream Research Company Ultra-high strength ausaged steels with excellent cryogenic temperature toughness and method of making thereof
JP2000080440A (ja) * 1998-08-31 2000-03-21 Kawasaki Steel Corp 高強度冷延薄鋼板およびその製造方法
JP2001226741A (ja) * 2000-02-15 2001-08-21 Kawasaki Steel Corp 伸びフランジ加工性に優れた高強度冷延鋼板およびその製造方法
JP2001267386A (ja) 2000-03-22 2001-09-28 Sony Corp 半導体装置用テスト回路
JP3958921B2 (ja) * 2000-08-04 2007-08-15 新日本製鐵株式会社 塗装焼付硬化性能と耐常温時効性に優れた冷延鋼板及びその製造方法
JP4304350B2 (ja) 2002-08-20 2009-07-29 雅則 平野 ポリヌクレオチドの合成方法
JP4068950B2 (ja) 2002-12-06 2008-03-26 株式会社神戸製鋼所 温間加工による伸び及び伸びフランジ性に優れた高強度鋼板、温間加工方法、及び温間加工された高強度部材または高強度部品
JP2005168405A (ja) 2003-12-11 2005-06-30 Ajinomoto Co Inc ジペプチドの製造方法
EP1559798B1 (fr) * 2004-01-28 2016-11-02 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) Tôle d'acier laminée à froid, à haute résistance, à bas rapport de limite d'élasticité et procédé pour sa fabrication
ATE426686T1 (de) * 2004-04-22 2009-04-15 Kobe Steel Ltd Hochfestes und kaltgewaltzes stahlblech mit hervorragender verformbarkeit und plattiertes stahlblech
JP4254663B2 (ja) * 2004-09-02 2009-04-15 住友金属工業株式会社 高強度薄鋼板およびその製造方法
JP2006089775A (ja) * 2004-09-21 2006-04-06 Nisshin Steel Co Ltd 耐久性に優れたタイヤ中子の製造方法
RU2292404C1 (ru) 2005-07-15 2007-01-27 Открытое акционерное общество "Северсталь" Способ производства полос для изготовления труб
JP4772496B2 (ja) * 2005-12-27 2011-09-14 新日本製鐵株式会社 穴拡げ性に優れた高強度冷延薄鋼板及びその製造方法
EP1832667A1 (fr) 2006-03-07 2007-09-12 ARCELOR France Procédé de fabrication de tôles d'acier à très hautes caractéristiques de résistance, de ductilité et de tenacité, et tôles ainsi produites
EP1990431A1 (fr) * 2007-05-11 2008-11-12 ArcelorMittal France Procédé de fabrication de tôles d'acier laminées à froid et recuites à très haute résistance, et tôles ainsi produites

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060144483A1 (en) * 2002-11-19 2006-07-06 Jean Beguinot Method for making an abrasion-resistant steel plate and plate obtained
US20060137768A1 (en) * 2004-12-28 2006-06-29 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High strength thin steel sheet having high hydrogen embrittlement resisting property

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10190187B2 (en) 2008-05-21 2019-01-29 Arcelormittal Manufacturing method for very high-strength, cold-rolled, dual-phase steel sheets
US20110168300A1 (en) * 2008-05-21 2011-07-14 Arcelormittal Investigacion Y Desarrollo Sl Manufacturing method for very high-strength cold-rolled dual-phase steel sheets and sheets so produced
US9427939B2 (en) * 2011-05-10 2016-08-30 ArcelorMittal Investigación y Desarrollo, S.L. Steel sheet with high mechanical strength, ductility and formability properties, production method and use of such sheets
WO2012153016A1 (fr) * 2011-05-10 2012-11-15 Arcelormittal Investigación Y Desarrollo Sl Tôle d'acier a hautes caracteristiques mecaniques de resistance, de ductilite et de formabilite, procede de fabrication et utilisation de telles tôles
US20140170439A1 (en) * 2011-05-10 2014-06-19 Arcelormittal Investigacion Y Desarollo Sl Steel sheet with high mechanical strength, ductility and formability properties, production method and use of such sheets
JP2014514459A (ja) * 2011-05-10 2014-06-19 アルセロルミタル・インベステイガシオン・イ・デサロジヨ・エセ・エレ 高い機械的強度、延性および成形性を有した鋼板、このような板材の特性、製造方法および使用
EP2730671B1 (fr) 2011-07-06 2017-11-01 Nippon Steel & Sumitomo Metal Corporation Feuille d'acier laminée à froid, plaquée par immersion à chaud, et son procédé de fabrication
US10774412B2 (en) 2011-07-06 2020-09-15 Nippon Steel Corporation Hot-dip galvanized cold-rolled steel sheet and process for producing same
US10358708B2 (en) * 2012-03-29 2019-07-23 Jfe Steel Corporation High strength steel plate having low yield ratio excellent in terms of strain ageing resistance, method of manufacturing the same and high strength welded steel pipe made of the same
US9611524B2 (en) 2012-03-30 2017-04-04 Kobe Steel, Ltd. High-yield-ratio high-strength steel sheet having excellent workability
WO2014016421A1 (fr) * 2012-07-27 2014-01-30 Thyssenkrupp Steel Europe Ag Produit plat en acier laminé à froid et son procédé de fabrication
EP2690184A1 (fr) * 2012-07-27 2014-01-29 ThyssenKrupp Steel Europe AG Cold rolled steel flat product and method for its production
US10301700B2 (en) 2013-08-22 2019-05-28 Thyssenkrupp Steel Europe Ag Method for producing a steel component
EP3150736A4 (fr) * 2014-05-29 2018-01-31 Nippon Steel & Sumitomo Metal Corporation Matériau d'acier traité à chaud et procédé pour le produire
US10718033B2 (en) 2014-05-29 2020-07-21 Nippon Steel Corporation Heat-treated steel material and method of manufacturing the same
CN104018069A (zh) * 2014-06-16 2014-09-03 武汉科技大学 一种高性能低碳含Mo贝氏体钢及其制备方法
US10907232B2 (en) 2014-07-03 2021-02-02 Arcelormittal Method for producing a high strength coated steel sheet having improved strength, formability and obtained sheet
US11718888B2 (en) 2014-07-03 2023-08-08 Arcelormittal Method for producing a high strength coated steel sheet having improved strength, formability and obtained sheet
US20180044774A1 (en) * 2015-02-19 2018-02-15 Arcelormittal Method of producing a phosphatable part from a sheet coated with an aluminum-based coating and a zinc coating
US10954580B2 (en) 2015-12-21 2021-03-23 Arcelormittal Method for producing a high strength steel sheet having improved strength and formability, and obtained high strength steel sheet
US10941476B2 (en) 2016-01-22 2021-03-09 Jfe Steel Corporation High strength steel sheet and method for producing the same
US11655516B2 (en) 2016-12-21 2023-05-23 Arcelormittal Tempered and coated steel sheet having excellent formability and a method of manufacturing the same
US11530461B2 (en) 2017-12-05 2022-12-20 Arcelormittal Cold rolled and annealed steel sheet and method of manufacturing the same

Also Published As

Publication number Publication date
EP2155915B1 (fr) 2017-10-25
US20200032366A1 (en) 2020-01-30
MA31555B1 (fr) 2010-08-02
WO2008145871A2 (fr) 2008-12-04
US20160355900A1 (en) 2016-12-08
CN101765668B (zh) 2011-12-21
CN101765668A (zh) 2010-06-30
RU2437945C2 (ru) 2011-12-27
EP2155915A2 (fr) 2010-02-24
EP2155915B2 (fr) 2022-04-27
JP2010526935A (ja) 2010-08-05
BRPI0821572B1 (pt) 2019-10-01
ES2655476T5 (es) 2022-09-29
RU2009145940A (ru) 2011-06-20
HUE035549T2 (en) 2018-05-28
US20220136078A1 (en) 2022-05-05
KR101523395B1 (ko) 2015-05-27
JP5398701B2 (ja) 2014-01-29
CA2686940C (fr) 2014-01-21
US10612106B2 (en) 2020-04-07
KR20100016438A (ko) 2010-02-12
ZA200907430B (en) 2010-07-28
PL2155915T5 (pl) 2022-09-05
WO2008145871A3 (fr) 2009-02-19
WO2008145871A8 (fr) 2019-09-06
ES2655476T3 (es) 2018-02-20
AR066508A1 (es) 2009-08-26
MX2009011927A (es) 2009-11-18
PL2155915T3 (pl) 2018-03-30
CA2686940A1 (fr) 2008-12-04
EP1990431A1 (fr) 2008-11-12
BRPI0821572A2 (pt) 2015-06-16
US11414722B2 (en) 2022-08-16

Similar Documents

Publication Publication Date Title
US20220136078A1 (en) Process for manufacturing cold-rolled and annealed steel sheet with a very high strength, and sheet thus produced
US20220282348A1 (en) Method for manufacturing a high strength steel product and steel product thereby obtained
US9732404B2 (en) Method of producing high-strength steel plates with excellent ductility and plates thus produced
US11279984B2 (en) High-strength cold rolled steel sheet having high formability and a method of manufacturing thereof
US9963756B2 (en) Method for production of martensitic steel having a very high yield point and sheet or part thus obtained
EP3720981B1 (fr) Tôle d'acier laminée à froid recuite et son procédé de fabrication
CN112739834A (zh) 经热轧的钢板及其制造方法
CN110621794B (zh) 具有优异延展性和可拉伸翻边性的高强度钢片
JP2007063604A (ja) 伸びと穴拡げ性に優れた溶融亜鉛めっき高強度鋼板およびその製造方法
KR20230049074A (ko) 성형성이 우수한 고강도 냉연강판 및 그 제조 방법
CA3163313C (fr) Tole d'acier laminee a froid et traitee thermiquement et procede de fabrication de celle-ci
CA3182944A1 (fr) Tole d'acier laminee a froid et traitee thermiquement et procede de fabrication de celle-ci
US20230287531A1 (en) Heat treated cold rolled steel sheet and a method of manufacturing thereof
CN114787396A (zh) 经热处理的冷轧钢板及其制造方法
US20210071278A1 (en) High yield ratio-type high-strength steel sheet and method for manufacturing same
CA3232766A1 (fr) Tole d'acier laminee a froid et traitee thermiquement et son procede de fabrication
US20230340630A1 (en) Cold rolled and coated steel sheet and a method of manufacturing thereof

Legal Events

Date Code Title Description
AS Assignment

Owner name: ARCELORMITTAL FRANCE, FRANCE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:GIL OTIN, JAVIER;MOULIN, ANTOINE;REEL/FRAME:024289/0523

Effective date: 20091102

STCB Information on status: application discontinuation

Free format text: ABANDONED -- AFTER EXAMINER'S ANSWER OR BOARD OF APPEALS DECISION