WO2017022025A1 - Tôle d'acier laminée à chaud à résistance élevée - Google Patents

Tôle d'acier laminée à chaud à résistance élevée Download PDF

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WO2017022025A1
WO2017022025A1 PCT/JP2015/071845 JP2015071845W WO2017022025A1 WO 2017022025 A1 WO2017022025 A1 WO 2017022025A1 JP 2015071845 W JP2015071845 W JP 2015071845W WO 2017022025 A1 WO2017022025 A1 WO 2017022025A1
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steel sheet
hot
rolled steel
ferrite
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PCT/JP2015/071845
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English (en)
Japanese (ja)
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杉浦　夏子
泰明 田中
卓史 横山
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新日鐵住金株式会社
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Priority to PCT/JP2015/071845 priority Critical patent/WO2017022025A1/fr
Priority to BR112018000633-5A priority patent/BR112018000633A2/pt
Priority to KR1020187002148A priority patent/KR102079968B1/ko
Priority to MX2018001140A priority patent/MX2018001140A/es
Priority to US15/744,690 priority patent/US20180209007A1/en
Priority to JP2017532259A priority patent/JP6485549B2/ja
Priority to EP15900339.1A priority patent/EP3330394B1/fr
Priority to CN201580082015.XA priority patent/CN107849651B/zh
Publication of WO2017022025A1 publication Critical patent/WO2017022025A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • C—CHEMISTRY; METALLURGY
    • 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
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/34—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
    • C—CHEMISTRY; METALLURGY
    • 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
    • C23C2/34—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the shape of the material to be treated
    • C23C2/36—Elongated material
    • C23C2/40—Plates; 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite
    • 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

Definitions

  • the present invention relates to a hot-rolled steel sheet, and more particularly, to a high-strength hot-rolled steel sheet excellent in hole expansibility and suitable for automobile undercarriage parts formed into various shapes by press working or the like.
  • Hot rolled steel sheets manufactured at a relatively low cost are widely used in various industrial equipment including automobiles.
  • High-strength hot-rolled steel sheets are used in automotive parts for the purpose of reducing vehicle weight and ensuring collision safety.
  • the application of is expanding.
  • steel sheets used for automobile parts not only strength but also various workability required at the time of part molding such as press formability and weldability must be satisfied.
  • stretch flange molding and burring molding are very frequently used for press molding. Therefore, the high-strength hot-rolled steel sheet used for the same part is required to have excellent hole expandability.
  • many suspension parts need to avoid plastic deformation even when a large load is applied from the viewpoint of ensuring safety. Therefore, a high yield ratio is required for the steel sheet used for the suspension part.
  • the steel structure is made of a single phase structure such as ferrite, bainitic ferrite, or bainite, It has been studied to strengthen the structure uniformly by solid solution strengthening such as Mn and Si and / or precipitation strengthening by carbide such as Ti, Nb and V or Cu.
  • Patent Document 1 discloses a technique related to a high-strength hot-rolled steel sheet excellent in hole expansibility, characterized by uniformly and finely dispersing Ti carbide containing Mo in a structure consisting essentially of a ferrite single phase. Has been.
  • the technique of Patent Document 1 is not suitable for mass production from an economical viewpoint because it is essential to add an extremely expensive alloy element called Mo.
  • Patent Document 2 for Ti-added steel containing a predetermined amount of Mn and Si, the cooling from hot rolling to winding is appropriately controlled, and the structure is made ferrite and bainite, and then TiC is finely precipitated.
  • the yield ratio which is one of the characteristics required for hot-rolled steel sheets applied to undercarriage parts.
  • bainite shows a low yield ratio as compared with precipitation strengthened ferrite, the technique of Patent Document 2 allows 50% bainite to be included, and it is assumed that a high yield ratio cannot be maintained.
  • Patent Document 2 the definition of the ferrite defined in Patent Document 2 is unclear, and it is conceivable that so-called bainitic ferrite and pseudo-polygonal ferrite, which are not polygonal ferrite, are included. This is because Patent Document 2 also allows a temperature range of 720 ° C. or lower where polygonal ferrite is not sufficiently generated as the first cooling stop temperature. Bainitic ferrite and pseudo-polygonal ferrite are structures having a lower yield ratio than polygonal ferrite.
  • Patent Document 3 discloses a Ti-added high-strength hot-rolled steel sheet that has improved toughness and hole expandability by reducing the Mn content and further controlling the proportion of C that precipitates as cementite.
  • Patent Document 4 discloses a technique related to a high-strength hot-rolled steel sheet that has excellent hole expansibility and that reduces the Mn and Si contents and suppresses the coarsening of TiC by adding a certain amount of Ti and B. It is disclosed.
  • Patent Document 5 steel containing a large amount of Si, Mn, and Ti is cooled under appropriate cooling conditions, and the structure is a granular bainitic ferrite single phase structure, with a high yield ratio and excellent hole expansibility.
  • a high-strength hot-rolled steel sheet having the following is disclosed.
  • Japanese Unexamined Patent Publication No. 2002-322540 Japanese Unexamined Patent Publication No. 2007-009322 Japanese Unexamined Patent Publication No. 10-287949 Japanese Unexamined Patent Publication No. 2012-026032 Japanese Unexamined Patent Publication No. 2004-307919
  • An object of the present invention is to provide a high-strength hot-rolled steel sheet having a high yield ratio and excellent hole expandability.
  • the high strength in the present invention means that the tensile strength (TS) is 540 MPa or more.
  • Ti is relatively inexpensive and exhibits significant precipitation strengthening when contained in a small amount.
  • the inventors presupposed that the structure of a hot-rolled steel sheet is mainly composed of polygonal ferrite in order to achieve excellent hole expansibility.
  • the present inventors examined utilizing precipitation strengthening of Ti in order to improve intensity
  • a method for improving the hole expandability has been intensively studied. As a result, the following knowledge was obtained.
  • the inventors measured the microhardness of individual ferrite grains of steel having a structure mainly composed of polygonal ferrite. As a result, it was found that the hardness was significantly different for each measured grain. Furthermore, it has been found that the hole expandability can be remarkably improved by reducing the variation in hardness of individual ferrite grains.
  • the present inventors observed the inside of the grains of polygonal ferrite of a sample with inferior hole expansibility using a transmission electron microscope. As a result, it was found that a large number of non equiaxed Ti-based carbides extending along a specific orientation of ferrite were precipitated, which had an adverse effect on hole expansibility. Conventionally, there has been almost no report that the shape of Ti carbide affects the hole expandability, and the mechanism by which the shape of the Ti-based carbide affects the hole expandability is not clear. However, compared to equiaxed Ti carbides, non-equal axis Ti carbides are highly compatible with the parent phase ferrite, and it is estimated that large matching strain is accumulated around them. Therefore, it is presumed that this alignment distortion promotes the propagation of cracks during the hole expanding process, so that the hole expandability deteriorates.
  • the hot-rolled steel sheet according to one embodiment of the present invention has a chemical composition of mass%, C: 0.010% to 0.200%, Si: 0.001% to 2.50%, Mn: 0 0.001% to 1.50%, P: 0.050% or less, S: 0.010% or less, N: 0.0070% or less, Al: 0.001% to 0.50%, Ti: 0.050 % To 0.30%, V: 0% to 0.50%, Nb: 0% to 0.090%, Cr: 0% to 0.50%, Ni: 0% to 0.50%, Cu: 0 -0.50%, Mo: 0% -0.50%, B: 0% -0.0050%, Ca: 0% -0.01%, Mg: 0% -0.01%, Bi: 0% Containing 0.01%, the balance being Fe and impurities, and the structure is 80% or more of polygonal ferrite in terms of area ratio, and a total of 5% or
  • the hot-rolled steel sheet according to the above (1) has the chemical composition of mass%, V: 0.010% to 0.50%, Nb: 0.001% to 0.090%, Cr: 0.001% to 0.50%, Ni: 0.001% to 0.50%, Cu: 0.001% to 0.50%, Mo: 0.001% to 0.50%, B: 0.00.
  • One or more selected from 0001% to 0.0050% may be contained.
  • the chemical composition is, in mass%, Ca: 0.0001% to 0.01%, Mg: 0.0001% to 0.01. %, Bi: One or more selected from 0.0001% to 0.01% may be contained.
  • the hot-rolled steel sheet according to any one of (1) to (3) may have a hot dip galvanized layer on the surface.
  • a high-strength hot-rolled steel sheet having a high yield ratio and excellent hole expandability can be manufactured at low cost.
  • the steel sheet according to the above aspect of the present invention has excellent hole expandability even in stretch flange molding that is frequently used in automobile parts, particularly suspension parts. Therefore, particularly in the automobile field, it contributes to reducing the weight of the vehicle body and ensuring collision safety.
  • FIG. 3 is a diagram showing an example of microhardness distribution of polygonal ferrite measured in Example 1.
  • FIG. 3 is a diagram showing an example of microhardness distribution of polygonal ferrite measured in Example 1.
  • the hot-rolled steel sheet according to this embodiment is (A) Chemical composition in mass%, C: 0.010% to 0.200%, Si: 0.001% to 2.50%, Mn: 0.001% to 1.50%, P: 0 0.050% or less, S: 0.010% or less, N: 0.0070% or less, Al: 0.001% to 0.50%, Ti: 0.050% to 0.30%, As necessary, V: 0.50% or less, Nb: 0.090% or less, Cr: 0.50% or less, Ni: 0.50% or less, Cu: 0.50% or less, Mo: 0.50%
  • B 0.0050% or less
  • Ca 0.01% or less
  • Mg 0.01% or less
  • Bi 0.01% or less
  • C is an essential element for increasing the strength by precipitation strengthening or solid solution strengthening of the steel sheet.
  • the C content is set to 0.010% or more.
  • it is 0.020% or more, more preferably 0.040% or more.
  • the C content is 0.200% or less.
  • it is 0.130% or less, More preferably, it is 0.110% or less.
  • Si is a solid solution strengthening element and is an element effective for increasing the strength of a steel sheet.
  • the Si content is set to 0.001% or more.
  • it is 0.01% or more, more preferably 0.04% or more.
  • the Si content is set to 2.50% or less.
  • it is 1.30% or less, More preferably, it is 0.80% or less.
  • Mn is an element effective for improving the strength of the steel sheet. Moreover, it is an element which suppresses the hot embrittlement by solid solution S by fixing S in steel as MnS.
  • the Mn content is set to 0.001% or more. Preferably, it is 0.10% or more, more preferably 0.45% or more.
  • the Mn content is 1.50% or less. Preferably it is 1.00% or less, More preferably, it is 0.80% or less.
  • P 0.050% or less
  • P is an element contained as an impurity, and deteriorates the weldability and toughness of the steel sheet. Therefore, it is preferable that the P content is small. However, when the P content exceeds 0.050%, the above-described influence becomes significant. Therefore, the P content is set to 0.050% or less as a range in which the deterioration of weldability and toughness is not remarkable. Preferably it is 0.020% or less, More preferably, it is 0.010% or less.
  • S is an element contained as an impurity, and forms MnS in the steel to deteriorate the hole expandability of the steel sheet. Therefore, it is preferable that the S content is small. However, when the S content exceeds 0.010%, the above-described influence becomes significant. Therefore, the S content is set to 0.010% or less as a range in which the deterioration of hole expansibility is not remarkable. Preferably it is 0.0050% or less, More preferably, it is 0.0020% or less.
  • N is an element contained as an impurity, and forms coarse nitrides in the steel to significantly deteriorate the hole expandability of the steel sheet. Therefore, it is preferable that the N content is small. However, when the N content exceeds 0.0070%, the above-described influence becomes significant. Therefore, the N content is set to 0.0070% or less as a range in which the deterioration of hole expansibility is not remarkable. Preferably it is 0.0050% or less.
  • Al 0.001% to 0.50%
  • Al is an element effective for deoxidation of steel.
  • the Al content is set to 0.001% or more.
  • the Al content is 0.50% or less.
  • it is 0.20% or less, More preferably, it is 0.10% or less.
  • Ti 0.050% to 0.30%
  • Ti is an element that forms carbides in steel and uniformly precipitates and strengthens ferrite. Moreover, it is an element which has the effect which reduces the amount of solute C by depositing as TiC, and inhibits the precipitation of cementite which deteriorates hole expansibility. Therefore, it is an especially important element in the hot-rolled steel sheet according to the present embodiment.
  • the Ti content is less than 0.050%, the effect is not sufficient, so the Ti content is set to 0.050% or more. Preferably, it is 0.100% or more, more preferably 0.130% or more.
  • the Ti content exceeds 0.30%, the toughness is remarkably deteriorated and unnecessary costs are increased. Therefore, the Ti content is set to 0.30% or less. Preferably it is 0.25% or less, more preferably 0.20% or less.
  • the hot-rolled steel sheet according to the present embodiment basically contains the chemical components described above, and the balance is composed of Fe and impurities. However, in order to further improve the strength and hole expansibility, it is selected from V, Nb, Cr, Ni, Cu, Mo, B, Ca, Mg, Bi in the following range instead of part of Fe. One or more of them may be contained. However, since these elements do not necessarily need to be contained, the lower limit is 0%.
  • an impurity means the component mixed by raw materials, such as an ore and a scrap, and other factors, when manufacturing steel materials industrially.
  • V 0.010% to 0.50%
  • V is an element that forms carbides in steel as in Ti.
  • V has a larger solubility product in austenite than Ti and is an effective element for increasing the strength of the steel sheet. Therefore, although it is more expensive than Ti, it may be contained if necessary.
  • the V content is set to 0.010% or more. Preferably it is 0.070% or more, More preferably, it is 0.140% or more. On the other hand, when the V content is excessive, the cost is increased. Therefore, even when V is contained, the V content is set to 0.50% or less.
  • Nb 0.001% to 0.090%
  • Nb like Ti, forms carbides in steel and is an effective element for increasing the strength of steel sheets. Therefore, although it is more expensive than Ti, it may be contained if necessary. If the Nb content is less than 0.001%, the above effect cannot be obtained sufficiently. To obtain the above effect, the Nb content is set to 0.001% or more. On the other hand, if the Nb content is excessive, the plastic anisotropy of the steel sheet increases and the hole expansibility deteriorates. Therefore, even when Nb is contained, the Nb content is set to 0.090% or less.
  • Cr 0.001% to 0.50%
  • Ni 0.001% to 0.50%
  • Cu 0.001% to 0.50%
  • Mo 0.001% to 0.50%
  • B 0.0001% to 0.0050%
  • Cr, Ni, Cu, Mo, and B are all effective elements for increasing the strength of the steel sheet. Therefore, you may contain individually or in combination of 2 or more types as needed. In order to obtain the above effects, Cr: 0.001% or more, Ni: 0.001% or more, Cu: 0.001% or more, Mo: 0.001% or more, B: 0.0001% or more, respectively. There is a need. On the other hand, these elements delay the ferrite transformation after hot rolling, similar to Mn.
  • the contents are Cr: 0.50% or less, Ni: 0.50% or less, Cu: 0.50% or less, Mo: 0.50% or less, B: 0.0050% or less.
  • Cr 0.20% or less, Ni: 0.20% or less, Cu: 0.20% or less, Mo: 0.09% or less, B: 0.0040% or less.
  • Ca and Mg are elements that contribute to fine dispersion of inclusions in the steel, and Bi is an element that reduces microsegregation of substitutional alloy elements such as Mn and Si in the steel. Since any element contributes to the improvement of the hole expandability of the steel sheet, it may be contained alone or in combination of two or more as required. In order to acquire the said effect, it is necessary to make it contain 0.0001% or more, respectively. On the other hand, if the content of these elements is excessive, the ductility deteriorates. Therefore, even when they are contained, the content of each element is 0.01% or less.
  • Polygonal ferrite area ratio 80% or more
  • Polygonal ferrite is an effective structure for improving hole expansibility.
  • the area ratio of polygonal ferrite is set to 80% or more. Preferably it is 90% or more, More preferably, it is 95% or more.
  • the area ratio of polygonal ferrite may be 100%, that is, the hot-rolled steel sheet according to this embodiment may be a polygonal ferrite single phase.
  • Total area ratio of martensite and austenite 5% or less
  • the total area ratio of martensite and austenite is set to 5% or less. Preferably it is 2% or less. Further, the total area ratio may be 0% (that is, no martensite and austenite are contained). The austenite here is so-called retained austenite.
  • Total area ratio of pearlite and cementite 5% or less
  • the total area ratio of pearlite and cementite is 5% or less.
  • it is 3% or less, More preferably, it is 1% or less.
  • the total area ratio may be 0% (that is, pearlite and cementite are not contained).
  • the remaining structure other than the above is at least one selected from bainitic ferrite and bainite. However, when the total area ratio of the above structure is 100%, bainitic ferrite and bainite are not included.
  • the above structure can be identified from the structure photograph after the structure is revealed by etching a sample cut out from the hot-rolled steel sheet.
  • Polygonal ferrite produced by a diffusive mechanism does not have an internal structure in the grain, and the grain boundary is on a straight line or an arc.
  • bainitic ferrite and bainite have an internal structure, and the grain boundary shape is ash, and have a structure distinctly different from polygonal ferrite. Therefore, polygonal ferrite and bainite or bainitic ferrite can be determined from the structure photograph obtained by using an optical microscope after etching with nital, depending on the grain boundary shape and the presence or absence of the internal structure.
  • the internal structure does not appear clearly and a grain boundary shape is an ash-cured structure (pseudopolygonal ferrite), it is counted as bainitic ferrite. Further, since cementite and pearlite are etched in black, the structure can be clearly identified. Moreover, the total area ratio of retained austenite and martensite can be calculated by performing image analysis on a structural photograph obtained with an optical microscope using a sample that has undergone repeller corrosion. In this embodiment, the structure of the steel sheet is observed at a position having a depth of 1/4 of the sheet thickness, which represents a typical structure of the steel sheet.
  • ⁇ HV is set to 30 or less. Since the standard deviation is preferably small, the lower limit of ⁇ HV is zero.
  • a specific method for measuring ⁇ HV will be described below.
  • the micro hardness is 50 polygonal ferrites (each crystal grain) selected at random using a micro hardness measuring device (trade name: FISCHERSCOPEHM2000 XYp) within a range of ⁇ 100 ⁇ m from the center plane in the thickness direction.
  • the indentation load is 20N.
  • the standard deviation ⁇ HV of the micro hardness is obtained from the obtained 50 pieces of data.
  • Ti-containing carbides present in the grains of polygonal ferrite 5 ⁇ 10 7 pieces / mm 2 or more] [50% or more of Ti-containing carbides present in polygonal ferrite grains are less than 3 in aspect ratio of long side / short side]
  • 5 ⁇ 10 7 pieces / mm 2 or more of Ti-containing carbide is included in the grains of polygonal ferrite. If it is 5 ⁇ 10 7 pieces / mm 2 or less, precipitation strengthening is insufficient and the strength is insufficient. On the other hand, it is not necessary to specify an upper limit, but usually, the amount is not more than 1 ⁇ 10 11 pieces / mm 2 in the above-described component range.
  • the ratio of the length of the long side to the length of the short side is 50% or more by number.
  • the ratio (carbide) less than 3
  • excellent hole expansibility can be obtained.
  • Ti-containing carbide having an aspect ratio of long side / short side of less than 3 is 2/3 or more of Ti-containing carbides present in the grains of polygonal ferrite.
  • the proportion of Ti-containing carbide having an aspect ratio of less than 3 may be 100%.
  • the proportion of the Ti-containing carbide having an aspect ratio of less than 3 is such that the incident direction of the electron beam is parallel to ⁇ 001> of the parent phase ferrite and at least 100 Ti-containing carbides are measured by a transmission electron microscope (magnification: 200,000 times). When observed above, it can be obtained by obtaining a carbide having an aspect ratio of the long side / short side of less than 3 with respect to the total number of Ti-containing carbides observed.
  • the Ti-containing carbide is a carbide containing Ti, and may further contain one or more of V and Nb. That is, it includes a state in which a Ti-containing carbide has a crystal structure (NaCl structure) and some of Ti positions are replaced by V or Nb.
  • the hot-rolled steel sheet according to this embodiment may have a known hot-dip galvanized layer on the surface.
  • the galvanized layer may be an alloyed galvannealed layer.
  • the corrosion resistance of the hot-rolled steel sheet is improved.
  • the hot-rolled steel sheet according to the present embodiment has all the high tensile strength, yield ratio, and tensile strength-hole expansibility balance (TS ⁇ ⁇ ) as described above by controlling the chemical composition and structure. Goal.
  • the tensile strength is preferably 590 MPa or more. Further, if the tensile strength exceeds 1180 MPa, the fatigue characteristics of the welded portion deteriorate, so 1180 MPa or less is preferable.
  • the hot-rolled steel sheet according to this embodiment is preferable because it can be stably manufactured according to the manufacturing method including the following steps (A) to (D).
  • a slab obtained from a molten steel having a chemical composition in the range described above is heated to about 1200 ° C.
  • C) The steel sheet after rough rolling has a cumulative reduction rate of 20% to 80% at 1050 ° C.
  • the slab having the above chemical composition is heated to about 1200 ° C.
  • the heating temperature is preferably 1150 ° C. to 1250 ° C.
  • the heated slab becomes a hot-rolled steel sheet through a hot rolling process including a rough rolling process and a finish rolling process.
  • a hot rolling process including a rough rolling process and a finish rolling process.
  • the cumulative rolling reduction at 1050 ° C. to 1150 ° C. is preferably 50% or more. If the cumulative rolling reduction at 1050 ° C. to 1150 ° C. is less than 50%, the structure becomes non-uniform, ⁇ HV increases, and the hole expandability may decrease.
  • the cumulative reduction ratio in the present invention is based on the inlet plate thickness before the first pass, and the cumulative reduction amount relative to this reference (the inlet plate thickness before the first pass in rolling and the outlet plate thickness after the final pass in rolling) %).
  • the cumulative rolling reduction is calculated separately for rough rolling and finish rolling. That is, the cumulative rolling reduction in rough rolling is the percentage of the difference between the inlet plate thickness before the first pass in rough rolling and the outlet plate thickness after the final pass in rough rolling, and the cumulative rolling reduction in finish rolling is It is the percentage of the difference between the inlet plate thickness before the first pass in finish rolling and the outlet plate thickness after the final pass in finish rolling.
  • the cumulative rolling reduction at 1050 ° C. or lower is preferably 20% to 80%.
  • the cumulative rolling reduction at 1050 ° C. or less exceeds 80%, the anisotropy of the structure of the finally obtained hot-rolled steel sheet becomes obvious. In this case, ⁇ HV may increase and the hole expandability may decrease. This is presumably due to the fact that the deviation of the crystal orientation of the ferrite grains promotes the hardness difference.
  • the rolling reduction in the final pass is preferably 15% to 35%.
  • the rolling reduction ratio of the final pass exceeds 35%, the anisotropy of the structure becomes obvious, and as a result, ⁇ Hv increases and the hole expansibility may decrease. Therefore, the rolling reduction of the final pass is set to 35% or less. More preferably, it is 25% or less.
  • the rolling reduction of the final pass is less than 15%, the accumulation of strain in austenite is insufficient, ferrite transformation after finish rolling is suppressed, and the finally obtained polygonal ferrite fraction and the microhardness of polygonal ferrite are reduced. There is a high possibility that the standard deviation of the height is out of the desired range and the hole expandability is deteriorated.
  • the finishing temperature (steel plate temperature after the final pass of finish rolling) is preferably 930 ° C. or higher.
  • the finishing temperature is lower than 930 ° C., the anisotropy of the structure tends to be manifested in the finally obtained hot-rolled steel sheet, and as a result, ⁇ Hv increases and the possibility that the hole expansibility decreases is increased.
  • the upper limit of the finishing temperature is preferably about 1000 ° C.
  • cooling the hot-rolled steel sheet at a low average cooling rate for a desired time determined according to the amount of Mn contained is the ferrite transformation and Ti-containing carbide. Is effective in bringing the final deviation of the polygonal ferrite fraction and the standard deviation of the microhardness of the polygonal ferrite into a desired range. Then, after further cooling, the hot rolled steel sheet is wound up. At that time, if the cooling rate is less than 30 ° C./s or the winding temperature is higher than 650 ° C., the Ti-containing carbide in the hot-rolled steel sheet becomes excessively coarse during cooling or after winding, and the desired strength is obtained. It may be difficult to ensure.
  • the coiling temperature control accuracy is lowered, which is not preferable. Therefore, it is effective to set the winding temperature in the range of 450 to 650 ° C. and to cool to the winding temperature at a predetermined average cooling rate or higher. That is, in the cooling process after finish rolling, the hot rolled steel sheet after finish rolling is set to i) primary cooling, and the temperature range from the final rolling final pass temperature to MT (720 ° C. ⁇ MT ⁇ 830 ° C.) has an average cooling rate.
  • [Mn] is the Mn content in unit mass%.
  • the following steps may be further provided as necessary.
  • ⁇ Plating process> You may provide the hot dip galvanization process which performs the hot dip galvanization process to the said hot-rolled steel plate after a winding process. By performing hot dip galvanizing treatment, a plated layer can be formed on the surface of the steel sheet, and the corrosion resistance of the steel sheet can be improved. Moreover, you may form an alloying hot-dip galvanization layer on the steel plate surface by giving an alloying treatment after the hot-dip galvanization processing. Moreover, in that case, in order to suppress the strength fall of a steel plate, it is preferable that the maximum heating temperature in annealing before hot dip galvanization immersion shall be 800 degrees C or less.
  • pickling may be performed after the hot rolling step according to a conventional method.
  • skin pass rolling may be performed for flattening correction and scale peeling promotion.
  • the elongation in the case of performing the skin pass rolling is not particularly specified, but is preferably 0.1% or more and less than 3.0%.
  • Example 1 Steel having the chemical composition shown in Table 1 was melted in a laboratory to cast a slab, and heating, hot rolling, cooling, and winding were performed in the pattern shown in FIG. At this time, the conditions in each step were as shown in Table 2.
  • Table 2 SRT, R1, R2, R3, FT, MT, t, and CT respectively indicate the following.
  • SRT Slab heating temperature
  • R1 Cumulative reduction ratio at 1050 ° C. or more and 1150 ° C. or less
  • R2 Cumulative reduction ratio at 1050 ° C.
  • R3 Reduction ratio at final finishing pass
  • FT Finishing rolling temperature
  • MT Primary cooling stop temperature
  • CT Secondary cooling time
  • a hole expansion test was performed in accordance with “JFS T 1001 Hole Expansion Test Method” of the Japan Iron and Steel Federation Standard, and the hole expansion ratio ( ⁇ ) was measured.
  • a sample including a cross section in the rolling direction of a hot-rolled steel sheet was collected, and after the surface corresponding to the cross section in the rolling direction of the sample was corroded with a nital liquid, the depth of the plate was reduced to 1 ⁇ 4 depth using an optical microscope or scanning electron microscope.
  • a tissue photograph obtained with a field of view of 300 ⁇ m ⁇ 300 ⁇ m was taken, and tissue identification was performed. From the obtained tissue photograph, the area ratio of each tissue was calculated by the point counting method.
  • Polygonal ferrite, bainite and bainitic ferrite were judged by the grain boundary shape and the presence or absence of internal structure, and the structure etched black was identified as cementite and pearlite. Moreover, the total area ratio of retained austenite and martensite was calculated by performing image analysis on the structure photograph obtained with an optical microscope using a sample that had undergone repeller corrosion. Further, a thin film sample is taken from each hot-rolled steel sheet, and a carbide containing one or more of Ti, V, and Nb precipitated in ferrite grains is observed using a transmission electron microscope (magnification: 200,000 times). The ratio in which the number density and the aspect ratio are 3 or less was determined.
  • FIG. 3A shows the measurement results of the micro hardness of the trial number 14 and FIG. 3B shows the micro hardness of the trial number 15 as an example.
  • V ⁇ , VP ⁇ , VMA, B, BF, and ⁇ HV represent the following. A blank in the tissue indicates that it was not observed.
  • V ⁇ Area ratio of ferrite VP ⁇ : Total area ratio of pearlite and cementite
  • VMA Total area ratio of martensite and austenite B
  • BF Bainite and bainitic ferrite
  • HV Standard deviation of ferrite micro hardness
  • Example 2 Next, among the steels having the chemical composition shown in Table 1, hot rolling and cooling shown in FIG. 1 were performed on five steel types A to C, G, and H. Then, the descaling process was performed and the heat processing which simulated the alloying hot-dip galvanizing line of the pattern shown in FIG. 2 was performed using the continuous heat processing simulator, without performing cold rolling. At this time, the conditions in each step were as shown in Table 5.
  • Table 5 RA, LTH, DIP, and GA represent the following.
  • RA Maximum heating temperature
  • LTH Low temperature holding temperature
  • DIP Zn bath temperature
  • GA Alloying temperature
  • a JIS No. 5 tensile specimen was taken from the hot rolled steel sheet thus obtained from the direction perpendicular to the rolling direction.
  • a thin film sample was taken from each hot-rolled steel sheet, and a carbide containing one or more of Ti, V, and Nb precipitated in ferrite grains was observed using a transmission electron microscope (magnification: 200,000 times). The ratio in which the number density and the aspect ratio are 3 or less was determined. The standard deviation of microhardness was measured by the method described above for steel from which 80% by area or more of polygonal ferrite was obtained.
  • Table 6 shows the obtained results.
  • the chemical composition and the structure are all within the range defined by the present invention, and the desired mechanical properties are obtained.
  • ⁇ HV exceeds the upper limit defined by the present invention, and as a result, desired mechanical properties are not obtained.
  • the polygonal ferrite area ratio is below the lower limit defined by the present invention, and as a result, desired mechanical properties are not obtained.
  • a high-strength hot-rolled steel sheet having a high yield ratio and excellent hole expandability can be manufactured at low cost.
  • the steel sheet according to the present invention has excellent hole expandability even in stretch flange forming, which is frequently used in automobile parts, particularly suspension parts. Therefore, it contributes to reducing the weight of the vehicle body and ensuring collision safety in industry, particularly in the automobile field.

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Abstract

L'invention concerne une tôle d'acier laminée à chaud, à résistance élevée, qui possède une composition chimique prescrite, cette composition contenant au moins 80% de ferrite polygonale, pas plus de 5% de martensite et d'austénite au total, et pas plus de 5 % de perlite et de cémentite au total (ces pourcentages étant exprimés en termes de surface), le reste étant constitué d'au moins un élément choisi parmi la ferrite bainitique et la bainite. σHV, qui est l'écart type de microdureté de 50 grains de ferrite polygonaux arbitraires présents dans une plage de ± 100 µm, à partir du plan central dans la direction d'épaisseur de la tôle, n'est pas supérieur à 30. Au moins 5 × 10 7 carbures/mm2 contenant Ti sont présents dans les grains de ferrite polygonale.<sp /> <sp /> Au moins 50 % des carbures contenant Ti possèdent un rapport d'aspect inférieur à 3, le rapport d'aspect étant le rapport entre la longueur du côté long et la longueur du côté court. La résistance à la traction est d'au moins 540 MPa.
PCT/JP2015/071845 2015-07-31 2015-07-31 Tôle d'acier laminée à chaud à résistance élevée WO2017022025A1 (fr)

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PCT/JP2015/071845 WO2017022025A1 (fr) 2015-07-31 2015-07-31 Tôle d'acier laminée à chaud à résistance élevée
BR112018000633-5A BR112018000633A2 (pt) 2015-07-31 2015-07-31 chapa de aço laminada a quente de alta resistência
KR1020187002148A KR102079968B1 (ko) 2015-07-31 2015-07-31 고강도 열연 강판
MX2018001140A MX2018001140A (es) 2015-07-31 2015-07-31 Lamina de acero laminada en caliente de alta resistencia.
US15/744,690 US20180209007A1 (en) 2015-07-31 2015-07-31 High strength hot rolled steel sheet
JP2017532259A JP6485549B2 (ja) 2015-07-31 2015-07-31 高強度熱延鋼板
EP15900339.1A EP3330394B1 (fr) 2015-07-31 2015-07-31 Tôle d'acier laminée à chaud à résistance élevée
CN201580082015.XA CN107849651B (zh) 2015-07-31 2015-07-31 高强度热轧钢板

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021187238A1 (fr) * 2020-03-19 2021-09-23 日本製鉄株式会社 Tôle d'acier

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2808342T3 (es) * 2016-09-22 2021-02-26 Tata Steel Ijmuiden Bv Un método para producir un acero de alta resistencia laminado en caliente con excelente capacidad de conformación con brida elástica y rendimiento de fatiga de bordes
CN110656292A (zh) * 2018-06-28 2020-01-07 上海梅山钢铁股份有限公司 一种抗拉强度440MPa级低屈强比高扩孔性热轧钢板
CN109047692B (zh) * 2018-08-22 2021-01-26 江阴兴澄特种钢铁有限公司 一种能够在-60℃条件下使用的超薄规格高强钢板及其制造方法
EP3998368A4 (fr) * 2019-07-10 2023-07-05 Nippon Steel Corporation Tôle en acier hautement résistante
CN112522568A (zh) * 2019-09-19 2021-03-19 宝山钢铁股份有限公司 一种耐火耐候钢板/带及其制造方法
KR20220098786A (ko) * 2020-01-17 2022-07-12 닛폰세이테츠 가부시키가이샤 강판 및 강관
US20230287530A1 (en) * 2020-04-17 2023-09-14 Nippon Steel Corporation High-strength hot-rolled steel sheet
EP3925771A1 (fr) * 2020-06-16 2021-12-22 SSAB Technology AB Produit d'acier à haute résistance et son procédé de fabrication
CN113005352B (zh) * 2021-02-08 2022-04-12 大连理工大学 一种外加纳米TiC强韧化马氏体钢的方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010265486A (ja) * 2009-05-12 2010-11-25 Jfe Steel Corp 高強度熱延鋼板およびその製造方法
JP5610103B2 (ja) * 2012-09-26 2014-10-22 新日鐵住金株式会社 複合組織鋼板およびその製造方法
JP2014208876A (ja) * 2013-03-29 2014-11-06 Ｊｆｅスチール株式会社 高強度熱延鋼板およびその製造方法

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3426465B2 (ja) 1997-04-15 2003-07-14 新日本製鐵株式会社 靱性と加工性に優れた４００〜８００Ｎ／ｍｍ２級高強度熱延鋼板及びその製造方法
JP3882577B2 (ja) 2000-10-31 2007-02-21 Ｊｆｅスチール株式会社 伸びおよび伸びフランジ性に優れた高張力熱延鋼板ならびにその製造方法および加工方法
JP4411005B2 (ja) 2003-04-04 2010-02-10 株式会社神戸製鋼所 成形性に優れた高強度熱延鋼板
CN100360698C (zh) * 2003-04-21 2008-01-09 杰富意钢铁株式会社 高强度热轧钢板及其制造方法
JP4649868B2 (ja) * 2003-04-21 2011-03-16 Ｊｆｅスチール株式会社 高強度熱延鋼板およびその製造方法
JP5070732B2 (ja) 2005-05-30 2012-11-14 Ｊｆｅスチール株式会社 伸び特性、伸びフランジ特性および引張疲労特性に優れた高強度熱延鋼板およびその製造方法
JP5765080B2 (ja) 2010-06-25 2015-08-19 Ｊｆｅスチール株式会社 伸びフランジ性に優れた高強度熱延鋼板およびその製造方法
JP5163835B2 (ja) * 2010-07-28 2013-03-13 新日鐵住金株式会社 熱延鋼板、冷延鋼板、亜鉛めっき鋼板およびこれらの製造方法
WO2013024860A1 (fr) * 2011-08-17 2013-02-21 株式会社神戸製鋼所 Tôle en acier laminée à chaud hautement résistante
JP5838796B2 (ja) * 2011-12-27 2016-01-06 Ｊｆｅスチール株式会社 伸びフランジ性に優れた高強度熱延鋼板およびその製造方法
KR20150000897A (ko) * 2012-04-06 2015-01-05 신닛테츠스미킨 카부시키카이샤 합금화 용융 아연 도금 열연 강판 및 그 제조 방법
JP6058439B2 (ja) * 2013-01-10 2017-01-11 株式会社神戸製鋼所 冷間加工性と加工後の表面硬さに優れる熱延鋼板
JP6177551B2 (ja) * 2013-03-15 2017-08-09 株式会社神戸製鋼所 絞り加工性と加工後の表面硬さに優れる熱延鋼板

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010265486A (ja) * 2009-05-12 2010-11-25 Jfe Steel Corp 高強度熱延鋼板およびその製造方法
JP5610103B2 (ja) * 2012-09-26 2014-10-22 新日鐵住金株式会社 複合組織鋼板およびその製造方法
JP2014208876A (ja) * 2013-03-29 2014-11-06 Ｊｆｅスチール株式会社 高強度熱延鋼板およびその製造方法

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021187238A1 (fr) * 2020-03-19 2021-09-23 日本製鉄株式会社 Tôle d'acier
JPWO2021187238A1 (fr) * 2020-03-19 2021-09-23
JP7277860B2 (ja) 2020-03-19 2023-05-19 日本製鉄株式会社 鋼板

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KR102079968B1 (ko) 2020-02-21
EP3330394A1 (fr) 2018-06-06
US20180209007A1 (en) 2018-07-26
KR20180019736A (ko) 2018-02-26
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BR112018000633A2 (pt) 2018-09-18

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