WO2016111275A1 - Tôle d'acier plaquée hautement résistante dotée d'excellentes propriétés de placage, d'usinage et de résistance à la fracture différée, et procédé de fabrication de celle-ci - Google Patents

Tôle d'acier plaquée hautement résistante dotée d'excellentes propriétés de placage, d'usinage et de résistance à la fracture différée, et procédé de fabrication de celle-ci Download PDF

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WO2016111275A1
WO2016111275A1 PCT/JP2016/050070 JP2016050070W WO2016111275A1 WO 2016111275 A1 WO2016111275 A1 WO 2016111275A1 JP 2016050070 W JP2016050070 W JP 2016050070W WO 2016111275 A1 WO2016111275 A1 WO 2016111275A1
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Prior art keywords
steel sheet
less
layer
average depth
strength
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PCT/JP2016/050070
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English (en)
Japanese (ja)
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宗朗 池田
二村　裕一
道治 中屋
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株式会社神戸製鋼所
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Priority claimed from JP2015159212A external-priority patent/JP6093411B2/ja
Application filed by 株式会社神戸製鋼所 filed Critical 株式会社神戸製鋼所
Priority to MX2017009018A priority Critical patent/MX2017009018A/es
Priority to KR1020177022030A priority patent/KR101843705B1/ko
Priority to CN201680005029.6A priority patent/CN107109574A/zh
Priority to US15/541,897 priority patent/US20180010226A1/en
Publication of WO2016111275A1 publication Critical patent/WO2016111275A1/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
    • 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
    • C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/06—Zinc or cadmium or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/26—After-treatment
    • C23C2/28—Thermal after-treatment, e.g. treatment in oil bath
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/26—After-treatment
    • C23C2/28—Thermal after-treatment, e.g. treatment in oil bath
    • C23C2/29—Cooling or quenching
    • 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

Definitions

  • the present invention relates to a high-strength plated steel sheet having a tensile strength of 980 MPa or more, plateability; workability including balance between strength and ductility, bendability and hole expansibility; and delayed fracture resistance, and a method for producing the same.
  • the plated steel sheet of the present invention includes both hot-dip galvanized steel sheets and alloyed hot-dip galvanized steel sheets.
  • Hot-dip galvanized steel sheets and alloyed hot-dip galvanized steel sheets which are widely used in fields such as automobiles and transportation equipment, are processed to increase strength, balance between strength and ductility, bendability, and hole expandability (stretch flangeability). And excellent in delayed fracture resistance.
  • Patent Document 1 discloses a hot-dip galvanized steel sheet having a tensile strength of 590 MPa or more and excellent bendability and corrosion resistance of a processed part. Specifically, in Patent Document 1, in order to suppress the occurrence of bending cracks and damage to the plating film due to the internal oxide layer formed on the steel plate side from the interface between the steel plate and the plating layer, the growth of the internal oxide layer is suppressed. Therefore, the growth of the decarburized layer is remarkably accelerated. Further, a near-surface structure is disclosed in which the thickness of the internal oxide layer in the ferrite region formed by decarburization is controlled to be thin.
  • Patent Document 2 discloses a hot-dip galvanized steel sheet having a fatigue strength, hydrogen embrittlement resistance (synonymous with delayed fracture resistance), and a tensile strength excellent in bendability of 770 MPa or more.
  • the steel plate portion is configured to have a soft layer that is in direct contact with the interface with the plating layer, and a soft layer that has ferrite with a maximum area ratio structure.
  • the thickness D of the soft layer and the depth d from the plating / base metal interface of the oxide containing one or more of Si and Mn existing in the steel sheet surface layer portion are d / 4 ⁇ D ⁇ 2d.
  • a hot-dip galvanized steel sheet that satisfies the requirements is disclosed.
  • Patent Document 3 discloses a high-strength cold-rolled steel sheet having excellent bendability and a maximum tensile strength of 700 MPa or more. Specifically, in Patent Document 3, whether or not a steel sheet surface layer can be softened by performing a decarburizing process, and even if it is a high-strength cold-rolled steel sheet having a maximum tensile strength of 700 MPa or more, it is as if it is a low-strength steel sheet. It is described that excellent bendability such as can be obtained.
  • Patent Document 4 discloses a high-strength hot-dip galvanized steel sheet that is excellent in delayed fracture resistance without impairing ductility and strength, and that has little anisotropy in delayed fracture resistance even in a thin plate.
  • the surface layer portion of the base steel plate in order to prevent delayed fracture starting from the surface layer portion of the base steel plate, is a decarburized layer having a small hard structure, and a hydrogen trap is included in the decarburized layer. It describes that fine oxides acting as sites are dispersed at high density.
  • Patent Document 5 discloses a high-strength steel sheet having a maximum tensile strength of 900 MPa or more that provides excellent formability and hydrogen embrittlement resistance. Specifically, Patent Document 5 has a decarburized layer (softening layer) that is softer than the inside of the steel sheet on the surface layer of the steel sheet, so that it has excellent hydrogen embrittlement resistance as if it were a low-strength steel sheet. It is described that (delayed fracture resistance) can be obtained.
  • the present invention has been made in view of the above circumstances, and its purpose is to provide a plated zinc; a balance between strength and ductility, workability of bendability and hole expansibility; and hot zinc of 980 MPa or more excellent in delayed fracture resistance.
  • An object of the present invention is to provide a plated steel sheet, a galvannealed steel sheet, and a method for producing the same.
  • the high-strength plated steel sheet having a tensile strength of 980 MPa or more is a plated steel sheet having a hot-dip galvanized layer or an alloyed hot-dip galvanized layer on the surface of the base steel sheet,
  • the base steel sheet is, in mass%, C: 0.05 to 0.25%, Si: 0.25 to 3%, Mn: 1.5 to 4%, P: more than 0% and 0.1% S: more than 0% and 0.05% or less, Al: 0.005 to 1%, and N: more than 0% and 0.01% or less, with the balance consisting of iron and inevitable impurities,
  • the base steel sheet further contains at least one of the following (a) to (c) by mass%.
  • Cu more than 0% and 1% or less
  • Ni At least one selected from the group consisting of more than 0% and 1% or less
  • the average depth d of the internal oxide layer and the average depth D of the soft layer satisfy a relationship of D> 2d.
  • the manufacturing method of the present invention that has solved the above-mentioned problems is a method for manufacturing the high-strength plated steel sheet according to any one of the above, and a hot-rolled steel sheet that satisfies the above-described components in the steel at 600 ° C.
  • a hot rolling step of winding at the above temperature a step of pickling and cold rolling so that the average depth d of the internal oxide layer remains 4 ⁇ m or more; an air ratio of 0.9 to 1.4 in the oxidation zone And a step of soaking in the reduction zone within the range of (Ac 1 point + 50 ° C.) to (Ac 3 point + 20 ° C.); and soaking; And a step of cooling at an average cooling rate of at least ° C./second.
  • another manufacturing method of the present invention that can solve the above-mentioned problems is a method for manufacturing the high-strength plated steel sheet according to any one of the above, and a hot-rolled steel sheet that satisfies the above-described components in the steel, A hot rolling step of winding at a temperature of 500 ° C. or higher; a step of keeping the temperature at a temperature of 500 ° C.
  • the plated steel sheet of the present invention includes an internal oxide layer containing at least one oxide selected from the group consisting of Si and Mn from the interface between the plating layer and the base steel sheet to the base steel sheet side, and a region of the internal oxide layer.
  • a soft layer and a hard layer other than the soft layer including, as a matrix structure, martensite and bainite: 60 area% or more and less than 95 area%, polygonal ferrite: more than 5 area% and less than 40 area%)
  • the average depth d of the internal oxide layer is controlled to be 4 ⁇ m or more and used as a hydrogen trap site, hydrogen embrittlement can be effectively suppressed
  • a high-strength plated steel sheet having a tensile strength of 980 MPa or more excellent in all workability such as balance of ductility, bendability and hole expansibility; delayed fracture resistance can be obtained.
  • the relationship between the average depth d of the internal oxide layer and the average depth D of the soft layer including the region of the internal oxide layer is appropriately
  • FIG. 1 is a diagram schematically illustrating a layer configuration from the interface between a plating layer and a base steel plate to the base steel plate side in the plated steel plate of the present invention.
  • FIG. 2 is an explanatory diagram for measuring the average depth d of the internal oxide layer in the plated steel sheet of the present invention.
  • FIG. 3 is a diagram for explaining the measurement position of the Vickers hardness used for determining the average depth D of the soft layer.
  • the inventors of the present invention have a high strength of 980 MPa or more in a base steel plate rich in Si and Mn, and are excellent in all of plating properties, workability, delayed fracture resistance, and shock absorption.
  • investigations have been made focusing on the layer structure from the interface between the plating layer and the base steel sheet to the base steel sheet side.
  • the internal oxide layer can function as a hydrogen trap site, and hydrogen embrittlement occurs.
  • the relationship between the average depth d of the internal oxide layer and the average depth D of the soft layer including the region of the internal oxide layer Properly If your found that is further improved in particular bending resistance and delayed fracture resistance, and have completed the present invention.
  • the plated steel sheet includes both a hot dip galvanized steel sheet and an alloyed hot dip galvanized steel sheet.
  • a base steel plate means the steel plate before a hot-dip galvanized layer and an alloying hot-dip galvanized layer are formed, and is distinguished from the said plated steel plate.
  • high strength means that the tensile strength is 980 MPa or more.
  • excellent workability means excellent balance between strength and ductility, bendability and hole expansibility. For details, when these characteristics are measured by the method described in the examples described later, those satisfying the acceptance criteria of the examples are referred to as “excellent workability”.
  • the plated steel sheet of the present invention has a hot dip galvanized layer or an alloyed hot dip galvanized layer (hereinafter sometimes represented by a plated layer) on the surface of the base steel sheet.
  • the characteristic part of the present invention is that it has the following layer configurations (A) to (C) in order from the interface between the base steel plate and the plating layer toward the base steel plate side.
  • (A) Internal oxide layer a layer containing at least one oxide selected from the group consisting of Si and Mn.
  • the average depth d of the internal oxide layer is 4 ⁇ m or more and less than the average depth D of the soft layer described in (B) described later.
  • (B) Soft layer including the internal oxide layer, where the thickness of the base steel sheet is t, the Vickers hardness satisfies 90% or less of the Vickers hardness at t / 4 part of the base steel sheet.
  • the average depth D of the soft layer is 20 ⁇ m or more.
  • the layer structure of the plated steel sheet according to the present invention on the base steel sheet 2 side is from the interface between the plating layer 1 and the base steel sheet 2 toward the base steel sheet 2 side, A hard layer 5 of (C) is provided inside the base steel plate 2 from the layer 4.
  • the soft layer 4 of (B) includes the internal oxide layer 3 of (A). The soft layer 4 and the hard layer 5 are continuously present.
  • the portion directly in contact with the interface between the plating layer 1 and the base steel plate 2 has an internal oxide layer 3 having an average depth d of 4 ⁇ m or more.
  • the average depth means the average depth from the interface, and a detailed measurement method thereof will be described with reference to FIG.
  • the internal oxide layer 3 is composed of an oxide containing at least one of Si and Mn, and a Si and Mn depletion layer in which Si and Mn form an oxide to form a solid solution Si or a small amount of solid solution Mn. .
  • the greatest feature is that the average depth d of the internal oxide layer 3 is controlled to be 4 ⁇ m or more.
  • the internal oxide layer can be used as a hydrogen trap site, hydrogen embrittlement can be suppressed, and bendability, hole expansibility, and delayed fracture resistance are improved.
  • the surface of the base steel sheet is oxidized with Si oxide and Mn oxide during annealing (oxidation / reduction process in a continuous hot-dip galvanizing line described later).
  • Si oxide and Mn oxide during annealing
  • an oxide film having a composite oxide of Si and Mn is easily formed, and the plating property is hindered. Therefore, as a countermeasure, a method is known in which the surface of the base steel sheet is oxidized in an oxidizing atmosphere to form a Fe oxide film, and then annealed (reduction annealing) in an atmosphere containing hydrogen.
  • the oxidizable elements are fixed as oxides inside the base steel sheet surface layer, and by reducing the oxidizable elements dissolved in the base steel sheet surface layer, A method for preventing the formation of an oxide film on the surface of the base steel plate is also known.
  • the use of at least one oxide selected from the group consisting of Si and Mn is effective in improving the deterioration of bendability and hole expansibility due to crystallization.
  • the above oxide is useful as a hydrogen trap site that prevents hydrogen from entering the base steel sheet during reduction, and can improve bendability, hole expansibility, and delayed fracture resistance.
  • the average depth d of the internal oxide layer containing the oxide is as thick as 4 ⁇ m or more.
  • the upper limit of the average depth d of the internal oxide layer is at least less than the average depth D of the soft layer (B) described later.
  • the upper limit of d is preferably 30 ⁇ m or less.
  • the d is more preferably 18 ⁇ m or less, and still more preferably 16 ⁇ m or less.
  • said d is 6 micrometers or more, and it is more preferable that it is 8 micrometers or more.
  • the average depth d of the internal oxide layer is preferably controlled so as to satisfy the relational expression of D> 2d in relation to the average depth D of the soft layer (B) described later. This further improves the bendability and delayed fracture resistance, particularly bendability.
  • the oxide existing depth d and the soft layer thickness substantially correspond to the average depth d of the internal oxide layer and the average depth D of the soft layer described in the present invention.
  • D a hot dip galvanized steel sheet satisfying d / 4 ⁇ D ⁇ 2d is disclosed, and the control directivity is completely different from the relational expression (D> 2d) defined in the present invention.
  • Patent Document 2 describes that the range of the oxide depth d is controlled while basically satisfying the relationship of d / 4 ⁇ D ⁇ 2d described above.
  • the average depth d of the internal oxide layer is controlled to be thicker than 4 ⁇ m.
  • this does not describe the effect of the present invention that the action as a hydrogen trap site is effectively exhibited and the bendability, hole expansibility, and delayed fracture resistance are improved.
  • the average depth of the internal oxide layer in the cold rolled steel sheet before passing through the continuous hot dip galvanizing line is 4 ⁇ m or more. It is necessary to control. Details will be described later in the column of the manufacturing method. That is, as shown in the examples described later, the internal oxide layer after pickling and cold rolling is succeeded to the internal oxide layer in the plated steel sheet finally obtained after passing through the plating line.
  • the soft layer 4 is a layer including the region of the internal oxide layer 3 of the above (A) and has a Vickers hardness of the base steel plate 2. It satisfies 90% or less of the Vickers hardness at t / 4 part. A detailed method for measuring the Vickers hardness will be described in the column of Examples described later.
  • the soft layer is a soft structure having a Vickers hardness lower than that of the hard layer (C) described later, and is excellent in deformability, so that bendability is particularly improved. That is, at the time of bending, the surface steel plate surface layer portion becomes a starting point of cracking, but the bendability is particularly improved by forming a predetermined soft layer on the surface steel plate surface layer as in the present invention. Furthermore, by forming the soft layer, it is possible to prevent the oxide in (A) from becoming a starting point of cracking during bending, and it is possible to enjoy only the above-described merit as a hydrogen trap site. As a result, not only bendability but also delayed fracture resistance is further improved.
  • the average depth D of the soft layer is set to 20 ⁇ m or more.
  • the D is preferably 22 ⁇ m or more, and more preferably 24 ⁇ m or more.
  • the upper limit is preferably set to 100 ⁇ m or less.
  • the D is more preferably 60 ⁇ m or less.
  • the hard layer in the present invention is formed on the base steel plate 2 side of the soft layer 4 of the above (B), and martensite and bainite: 60 area% or more and 95 area % And polygonal ferrite: more than 5 area% and 40 area% or less.
  • the martensite of the hard layer 5 may be tempered.
  • the strength increases as the total area ratio of bainite and martensite increases (that is, the area ratio of ferrite decreases), and the ductility increases as the total area ratio of bainite and martensite decreases (that is, the area ratio of ferrite increases). Tend to improve. Further, when the area ratio of ferrite decreases, the balance between strength and elongation becomes worse.
  • the preferable area ratio of these tissues is appropriately set in consideration of the relationship with desired characteristics.
  • the total area ratio of bainite and martensite is preferably 80 area% or more, and the total area ratio of ferrite is preferably 20 area% or less.
  • the total area ratio of bainite and martensite is preferably 70 area% or less, and the total area ratio of ferrite is preferably 30 area% or more.
  • the hard layer may contain, in addition to the above structure, a structure that can be inevitably mixed in production, for example, retained austenite ( ⁇ ), pearlite, and the like within a range not impairing the action of the present invention.
  • the above structure is 15 area% or less at the maximum, and the smaller the better.
  • the organization is described as “Others” in Table 3 to be described later.
  • the hard layer in this invention should just contain bainite and a martensite in the range of 60 area% or more and less than 95 area% in a total area as mentioned above, and each ratio of a bainite and a martensite is not limited at all. .
  • both the aspect which is comprised only from bainite and does not contain martensite at all; conversely, the aspect comprised only from martensite and does not contain bainite at all are included in the scope of the present invention. From the above viewpoint, in the examples described later, bainite and martensite are not observed separately, only the total area is measured, and the results are shown in Table 3.
  • the plated steel sheet of the present invention has C: 0.05 to 0.25%, Si: 0.25 to 3%, Mn: 1.5 to 4%, P: more than 0% and 0.1% or less, S: 0 More than 0.05% or less, Al: 0.005 to 1%, and N: more than 0% and 0.01% or less, with the balance being iron and inevitable impurities.
  • C 0.05 to 0.25%
  • C is an element important for increasing the strength of steel due to the improvement of hardenability and the effect of hardening of martensite.
  • the lower limit of the C amount is set to 0.05% or more.
  • the minimum with the preferable amount of C is 0.08% or more, More preferably, it is 0.10% or more.
  • the upper limit of C content is set to 0.25%.
  • the upper limit with preferable C amount is 0.2% or less, More preferably, it is 0.18% or less.
  • Si 0.25 to 3%
  • Si is an element that increases the strength of steel by solid solution strengthening and is effective in improving workability. Moreover, it produces an internal oxide layer and has an action of suppressing hydrogen embrittlement.
  • the lower limit of the Si amount is set to 0.25% or more.
  • the minimum with the preferable amount of Si is 0.3% or more, More preferably, it is 0.5% or more, More preferably, it is 0.7% or more.
  • Si is a ferrite-forming element, and when Si is added excessively, the formation of ferrite cannot be suppressed, the hardness difference between the soft phase and the hard phase increases, and the workability decreases.
  • the upper limit of the Si amount is set to 3%.
  • the upper limit with the preferable amount of Si is 2.5% or less, More preferably, it is 2.0% or less.
  • Mn 1.5-4% Mn is an element that improves hardenability, suppresses ferrite and bainite, generates martensite, and contributes to high strength.
  • the lower limit of the amount of Mn is set to 1.5% or more.
  • the minimum with the preferable amount of Mn is 1.8% or more, More preferably, it is 2.0% or more.
  • the upper limit of the Mn amount is 4%.
  • the upper limit with the preferable amount of Mn is 3.5% or less.
  • P more than 0% and 0.1% or less P is an element useful for strengthening steel as a solid solution strengthening element.
  • the lower limit of the P amount is set to more than 0%.
  • the upper limit is made 0.1% or less.
  • the amount of P is preferably as small as possible, preferably 0.03% or less, more preferably 0.015% or less.
  • S more than 0% and 0.05% or less S is an element that is unavoidably contained, and forms sulfides such as MnS, which may cause cracks and deteriorate workability. Therefore, the upper limit of the S amount is set to 0.05% or less.
  • the amount of S should be small, preferably 0.01% or less, more preferably 0.008% or less.
  • Al acts as a deoxidizer. Further, Al combines with N to become AlN, and the workability and delayed fracture resistance are improved by making the austenite grain size finer.
  • the lower limit of the Al amount is set to 0.005% or more.
  • the minimum with the preferable amount of Al is 0.01% or more, More preferably, it is 0.02% or more.
  • the upper limit of the Al amount is 1%.
  • the upper limit with preferable Al amount is 0.8% or less, More preferably, it is 0.6% or less.
  • N more than 0% and 0.01% or less N is an element inevitably contained, but if it is contained excessively, workability deteriorates.
  • B boron
  • BN precipitates are generated and inhibit the effect of improving the hardenability by B. Therefore, it is better to reduce N as much as possible. Therefore, the upper limit of the N amount is 0.01% or less.
  • the upper limit with preferable N amount is 0.008% or less, More preferably, it is 0.005% or less.
  • the plated steel sheet of the present invention contains the above components, with the balance being iron and inevitable impurities.
  • Cr more than 0% and less than 1%
  • Mo more than 0% and less than 1%
  • B more than 0% and less than 0.01%.
  • the preferable lower limit of the Cr amount is set to 0.01% or more. However, if Cr is added excessively, the plating property is lowered. Moreover, Cr carbide
  • the preferable lower limit of the Mo amount is 0.01% or more.
  • the preferable upper limit of Mo is 1% or less. More preferably, it is 0.5% or less, More preferably, it is 0.3% or less.
  • the preferable lower limit of the B amount is set to 0.0002% or more. More preferably, it is 0.0010% or more. However, when the amount of B becomes excessive, the hot workability deteriorates, so the preferable upper limit of the amount of B is made 0.01% or less. More preferably, it is 0.0070% or less, More preferably, it is 0.0050% or less.
  • the preferable lower limit of each of Ti, Nb, and V is set to 0.01% or more.
  • the preferable upper limit of each element is set to 0.2% or less. Any element is more preferably 0.15% or less, and still more preferably 0.10% or less.
  • At least one selected from the group consisting of Cu: more than 0% and not more than 1% and Ni: more than 0% and not more than 1% is an element effective for increasing the strength. These elements may be added alone or in combination.
  • the preferable lower limit of Cu and Ni is set to 0.01% or more.
  • the preferable upper limit of each element is 1% or less. Any element is more preferably 0.8% or less, and still more preferably 0.5% or less.
  • the production method of the present invention includes a first method in which pickling is performed immediately after hot rolling without holding the heat, and a second method in which pickling is performed after warming after hot rolling.
  • the lower limit of the hot rolling coiling temperature is different between the first method (without heat retention) and the second method (with heat retention), but the other steps are the same. Details will be described below.
  • the first production method according to the present invention includes a hot rolling process, a pickling process, a cold rolling process, an oxidation process, a reduction process, and a plating process in a continuous molten Zn plating line (CGL (Continuous Galvanizing Line)). Broadly divided.
  • the characteristic part of this invention is the hot rolling process of obtaining the hot rolled steel plate which formed the internal oxide layer by winding the steel plate which satisfies the said steel component at the temperature of 600 degreeC or more; average depth of an internal oxide layer; Pickling and cold rolling so that the thickness d remains 4 ⁇ m or more; oxidizing in an oxidation zone at an air ratio of 0.9 to 1.4; and in a reduction zone (Ac 1 point + 50 ° C. ) To (Ac 3 points + 20 ° C.) and soaking; and after soaking, cooling to the cooling stop temperature at an average cooling rate of 5 ° C./second or more.
  • Hot rolling may be performed according to a conventional method.
  • the heating temperature is preferably about 1150 to 1300 ° C.
  • the finish rolling temperature is preferably controlled to about 850 to 950 ° C.
  • the coiling temperature after hot rolling it is important to control the coiling temperature after hot rolling to 600 degreeC or more.
  • an internal oxide layer is formed on the surface of the base steel plate, and a soft layer is also formed by decarburization, so that a desired internal oxide layer and soft layer can be obtained on the steel plate after plating.
  • the coiling temperature is less than 600 ° C., the internal oxide layer and the soft layer are not sufficiently formed.
  • the strength of the hot-rolled steel sheet is increased, and the cold-rollability is reduced.
  • a preferable winding temperature is 620 ° C. or higher, and more preferably 640 ° C. or higher.
  • the upper limit is preferably made 750 ° C. or lower.
  • the hot-rolled steel sheet thus obtained is pickled and cold-rolled so that the average depth d of the internal oxide layer remains at 4 ⁇ m or more.
  • the average depth d of the internal oxide layer remains at 4 ⁇ m or more.
  • the soft layer remains, so that a desired soft layer can be easily formed after plating.
  • mineral acids such as hydrochloric acid, sulfuric acid, and nitric acid can be used.
  • the concentration and temperature of the pickling solution are high and the pickling time is long, the internal oxide layer tends to dissolve and become thin. Conversely, if the concentration and temperature of the pickling solution are low and the pickling time is short, removal of the black skin scale layer by pickling becomes insufficient. Therefore, for example, when hydrochloric acid is used, it is recommended to control the concentration to about 3 to 20%, the temperature to 60 to 90 ° C., and the time to about 35 to 200 seconds.
  • the number of pickling tanks is not particularly limited, and a plurality of pickling tanks may be used.
  • a pickling inhibitor such as an amine, that is, an inhibitor, a pickling accelerator, or the like may be added to the pickling solution.
  • cold rolling is performed so that the average depth d of the internal oxide layer remains 4 ⁇ m or more.
  • the cold rolling conditions are preferably controlled so that the cold rolling rate is in the range of about 20 to 70%.
  • oxidation is performed at an air ratio of 0.9 to 1.4 in an oxidation zone.
  • the air ratio means the ratio of the amount of air actually supplied to the amount of air that is theoretically required to completely burn the supplied combustion gas.
  • oxygen is in an excess state
  • oxygen is in a shortage state.
  • CO gas is used as the combustion gas.
  • Oxidation in an atmosphere where the air ratio falls within the above range promotes decarburization, so that a desired soft layer is formed and bendability is improved.
  • an Fe oxide film can be generated on the surface, and generation of a composite oxide film or the like harmful to plating properties can be suppressed.
  • the air ratio needs to be controlled to 0.9 or more, and is preferably controlled to 1.0 or more.
  • the air ratio is as high as 1.4 or more, an Fe oxide film is excessively generated and cannot be sufficiently reduced in the next reduction furnace, thereby impairing the plateability.
  • the air ratio needs to be controlled to 1.4 or less, and is preferably controlled to 1.2 or less.
  • the preferable lower limit of the oxidation temperature is 500 ° C. or higher, more preferably 750 ° C. or higher.
  • the upper limit of the oxidation temperature is 900 ° C. or lower, more preferably 850 ° C. or lower.
  • the oxide film is reduced in a hydrogen atmosphere in the reduction zone.
  • soaking is performed while maintaining in a range of (Ac 1 point + 50 ° C.) to (Ac 3 point + 20 ° C.).
  • the preferable soaking temperature is (Ac 1 point + 100 ° C.) or more and Ac 3 point ° C. or less.
  • the Ac 1 point is calculated based on the following equation (i).
  • [] represents the content (% by mass) of each element. This equation is described in “Leslie Steel Material Science” (published by Maruzen Co., Ltd., William C. Leslie, p273).
  • Ac 1 (° C.) 723-10.7 ⁇ [Mn] ⁇ 16.9 ⁇ [Ni] + 29.1 ⁇ [Si] + 16.9 ⁇ [Cr] + 290 ⁇ [As] + 6.38 ⁇ [W] ⁇ ⁇ (I)
  • the Ac 3 point is calculated based on the following equation (ii).
  • [] represents the content (% by mass) of each element. This equation is described in “Leslie Steel Material Science” (published by Maruzen Co., Ltd., William C. Leslie, p273).
  • the holding time at the soaking temperature is preferably 10 seconds or more. If the holding time is less than 10 seconds, the reduction is insufficient and the plating property is hindered. More preferably, it is 30 seconds or more, More preferably, it is 50 seconds or more.
  • the holding time at the time of soaking is not particularly limited from the above viewpoint, but is preferably controlled to about 100 seconds or less, more preferably about 80 seconds or less in consideration of productivity.
  • the atmosphere of the reduction zone contains hydrogen and nitrogen, and the hydrogen concentration is preferably controlled in the range of about 5 to 25% by volume.
  • the dew point is preferably controlled at -30 to -60 ° C.
  • the range up to the cooling stop temperature is cooled at an average cooling rate of 5 ° C./second or more.
  • the area ratio of the ferrite can be controlled within a predetermined range.
  • it is 8 degreeC / second or more, More preferably, it is 10 degreeC / second or more.
  • the upper limit of the average cooling rate is not particularly limited, but it is preferable to control the temperature to about 100 ° C./second or less in consideration of the ease of control of the base steel sheet temperature and the equipment cost.
  • a more preferable average cooling rate is 50 ° C./second or less, and further preferably 30 ° C./second or less.
  • the cooling stop temperature may be up to a temperature range where ferrite is not generated. For example, it is preferable to cool to 550 ° C. or lower.
  • a preferable lower limit of the cooling stop temperature is, for example, 400 ° C. or higher, more preferably 430 ° C. or higher, and further preferably 460 ° C. or higher.
  • the subsequent cooling method is not limited to the above.
  • the cooling may be performed below the above-described preferable cooling stop temperature (see, for example, No. 26 in Table 2 below). Or after cooling to predetermined temperature, you may cool with water.
  • hot dip galvanizing is performed according to a conventional method.
  • the method of hot dip galvanizing is not particularly limited, and for example, the preferred lower limit of the plating bath temperature is 400 ° C. or higher, more preferably 440 ° C. or higher.
  • the upper limit with the said preferable plating bath temperature is 500 degrees C or less, More preferably, it is 470 degrees C or less.
  • the composition of the plating bath is not particularly limited, and a known hot dip galvanizing bath may be used.
  • the cooling conditions after hot dip galvanizing are not particularly limited, and for example, the average cooling rate to room temperature is preferably controlled to about 1 ° C./second or more, more preferably 5 ° C./second or more.
  • the upper limit of the average cooling rate is not particularly defined, but is preferably controlled to about 50 ° C./second or less in consideration of ease of control of the base steel sheet temperature and equipment cost.
  • the average cooling rate is preferably 40 ° C./second or less, more preferably 30 ° C./second or less.
  • alloying treatment may be performed by a conventional method, whereby an alloyed hot-dip galvanized steel sheet is obtained.
  • the conditions for the alloying treatment are not particularly limited. For example, after performing hot dip galvanization under the above conditions, hold at about 500 to 600 ° C., particularly about 530 to 580 ° C. for about 5 to 30 seconds, particularly about 10 to 25 seconds. It is preferable to do so. Below the above range, alloying is insufficient. On the other hand, when the above range is exceeded, alloying proceeds excessively, and there is a possibility that plating peeling may occur during press molding of the plated steel sheet. Furthermore, it becomes easy to produce ferrite.
  • the alloying treatment may be performed using, for example, a heating furnace, a direct fire, or an infrared heating furnace.
  • the heating means is also not particularly limited, and for example, conventional means such as gas heating, induction heater heating, that is, heating by a high frequency induction heating device can be adopted.
  • an alloyed hot-dip galvanized steel sheet is obtained by cooling according to a conventional method.
  • the average cooling rate to room temperature is preferably controlled to about 1 ° C./second or more.
  • the second production method according to the present invention includes a hot rolling step of winding a hot-rolled steel sheet satisfying the above-mentioned components in the steel at a temperature of 500 ° C. or higher; a step of keeping the temperature at a temperature of 500 ° C.
  • the first manufacturing method includes the steps; In contrast to the first manufacturing method described above, in the second manufacturing method, the lower limit of the coiling temperature after hot rolling is set to 500 ° C. or more, and the heat retaining step is provided after the hot rolling step. Only the first manufacturing method is different. Therefore, only the difference will be described below. For the steps consistent with the first manufacturing method, the first manufacturing method may be referred to.
  • the reason for providing the heat-retaining step as described above is that it is possible to maintain for a long time in a temperature range that can be oxidized by heat-retaining, and to expand the lower limit of the coiling temperature range from which a desired internal oxide layer and soft layer can be obtained. .
  • the uniformity of the base steel sheet can be improved by reducing the temperature difference between the surface layer and the inside of the base steel sheet.
  • the coiling temperature after hot rolling is controlled to 500 ° C. or higher.
  • the temperature can be set lower than 600 ° C. which is the lower limit of the winding temperature in the first manufacturing method described above.
  • a preferable winding temperature is 540 ° C. or higher, more preferably 570 ° C. or higher.
  • the preferable upper limit of coiling temperature is the same as the 1st manufacturing method mentioned above, and it is preferable to set it as 750 degrees C or less.
  • the hot-rolled steel sheet thus obtained is kept at a temperature of 500 ° C. or more for 80 minutes or more. Thereby, a desired internal oxide layer can be obtained. It is preferable to keep the hot-rolled steel sheet in a heat-insulating device, for example, so that the above-mentioned effect due to heat insulation is effectively exhibited.
  • the said apparatus used for this invention will not be specifically limited if comprised with the heat insulating raw material, For example, a ceramic fiber etc. are used preferably as such a raw material.
  • a preferred temperature is 540 ° C. or higher, more preferably 560 ° C. or higher.
  • a preferable time is 100 minutes or more, More preferably, it is 120 minutes or more.
  • it is preferable to control the upper limit of the said temperature and time to about 700 degrees C or less and 500 minutes or less when pickling property, productivity, etc. are considered.
  • the plated steel sheet of the present invention obtained by the above-described production method is further subjected to various coatings and coating ground treatments, for example, chemical conversion treatment such as phosphate treatment; organic coating treatment, for example, formation of an organic coating such as a film laminate. May be.
  • various coatings and coating ground treatments for example, chemical conversion treatment such as phosphate treatment; organic coating treatment, for example, formation of an organic coating such as a film laminate. May be.
  • paint used for various coatings known resins such as epoxy resin, fluorine resin, silicon acrylic resin, polyurethane resin, acrylic resin, polyester resin, phenol resin, alkyd resin, melamine resin, and the like can be used. From the viewpoint of corrosion resistance, an epoxy resin, a fluororesin, and a silicon acrylic resin are preferable.
  • a curing agent may be used together with the resin.
  • the paint may also contain known additives such as coloring pigments, coupling agents, leveling agents, sensitizers, antioxidants, UV stabilizers, flame retardants and the like.
  • the form of paint is not particularly limited, and any form of paint such as solvent-based paint, water-based paint, water-dispersed paint, powder paint, and electrodeposition paint can be used.
  • the coating method is not particularly limited, and a dipping method, a roll coater method, a spray method, a curtain flow coater method, an electrodeposition coating method, and the like can be used. What is necessary is just to set suitably the thickness of coating layers, such as a plating layer, an organic membrane
  • the high-strength plated steel sheet of the present invention is ultra-high-strength, and is excellent in workability (bendability and hole expandability) and delayed fracture resistance, so that it is a strength component for automobiles such as front and rear side members. It can be used for body parts such as crash parts such as crash boxes, pillars such as center pillar reinforcements, roof rail reinforcements, side sills, floor members, and kick parts.
  • the balance was iron and inevitable impurity slabs heated to 1250 ° C., hot rolled to 2.4 mm at a finish rolling temperature of 900 ° C., and then wound up at the temperature shown in Table 2.
  • the hot-rolled steel sheet thus obtained was pickled under the following conditions and then cold-rolled at a cold rolling rate of 50%.
  • the plate thickness after cold rolling is 1.2 mm.
  • annealing oxidation, reduction
  • cooling were performed under the conditions shown in Table 2 in a continuous molten Zn plating line.
  • the temperature of the oxidation furnace installed in the continuous molten Zn plating line was controlled to 800 ° C.
  • the hydrogen concentration in the reduction furnace was 20% by volume
  • the balance was nitrogen and inevitable impurities, dew point: ⁇ 45 ° C.
  • the holding times at the soaking temperature shown in Table 2 were all 50 seconds.
  • the average depth of the internal oxide layer was measured not only on the plated steel sheet but also on the base steel sheet after pickling and cold rolling for reference. This is to confirm that the desired average depth of the internal oxide layer has already been obtained in the cold-rolled steel sheet before annealing by controlling the coiling temperature and pickling conditions after hot rolling. It is.
  • Pulse sputtering frequency 50Hz
  • Anode diameter (analysis area): Diameter 6 mm
  • Discharge power 30W
  • Ar gas pressure 2.5 hPa
  • the position where the Zn content and the Fe content from the surface of the plating layer become equal was defined as the interface between the plating layer and the base steel sheet.
  • the average value of the O amount at each measurement position at a depth of 40 to 50 ⁇ m from the surface of the plating layer is the average value of the bulk O amount, which is 0.02% higher than that, that is, the O amount ⁇ (the bulk O amount)
  • the average value + 0.02%) was defined as the internal oxide layer, and the maximum depth was defined as the internal oxide layer depth.
  • a similar test was performed using three test pieces, and the average was defined as the average depth d of the internal oxide layer.
  • the measurement is performed at a pitch of 10 ⁇ m from the interface between the plating layer 1 and the base steel plate 2 at a depth of 10 ⁇ m toward the inside of the thickness, and the measurement is performed every 5 ⁇ m at a pitch up to 100 ⁇ m.
  • Hardness was measured. Interval between measurement points; that is, the distance between x and x in FIG. 3 was at least 15 ⁇ m.
  • a region having a Vickers hardness of 90% or less compared with t / 4 part of the base steel plate was defined as a soft layer, and the depth was calculated.
  • the same treatment was performed at 10 places on the same test piece, and the average was defined as the average depth D of the soft layer.
  • TS ⁇ EL was calculated from the tensile strength and elongation obtained as described above.
  • TS ⁇ EL of 14000 or more was evaluated as having an excellent balance between strength and ductility (pass).
  • the bendability was evaluated for each tensile strength TS based on Rmin / t obtained by dividing Rmin by the plate thickness t of the base steel sheet. Details are as follows. In addition, the evaluation of bendability was not performed for TS not satisfying the acceptable standard of 980 MPa or more (indicated as “ ⁇ ” in Table 3). When TS is 980 MPa or more and less than 1080 MPa, Rmin / t ⁇ 1.5 is satisfied. When TS is 1080 MPa or more and less than 1180 MPa, Rmin / t ⁇ 2.5 is satisfied. When TS is 1180 MPa or more, Rmin / t ⁇ 3. .2 passed
  • No. Examples 1 to 12, 16, 18, 21, 25, 26, 27, 30 to 42 are examples that satisfy the requirements of the present invention, and include strength, workability [balance between strength and ductility (TS ⁇ EL), bendability and Hole expandability ( ⁇ )], delayed fracture resistance, and plating properties were all good.
  • the average depth d of the internal oxide layer and the average depth D of the soft layer satisfy the relationship of D> 2d (ie, the value of “D / 2d” in Table 2 exceeds 1).
  • No. 13 is an example using the steel type M of Table 1 with a large amount of C, and the bendability, ⁇ , and delayed fracture resistance were lowered.
  • No. No. 14 is an example using the steel type N of Table 1 with a small amount of Si, and the internal oxide layer was not sufficiently formed, and the bendability, ⁇ , balance between strength and ductility, and delayed fracture resistance were deteriorated.
  • No. No. 15 is an example in which the steel type A in Table 1 whose components in the steel satisfy the requirements of the present invention was used, but the coiling temperature during hot rolling was low, and the average depth of the internal oxide layer after pickling and cold rolling Therefore, the average depth d of the internal oxide layer after plating and the average depth D of the soft layer were also reduced. As a result, the bendability, ⁇ , delayed fracture resistance, and plating properties decreased.
  • No. No. 17 used the steel type A in Table 1 whose components in the steel satisfy the requirements of the present invention, but is an example of a high soaking temperature, and since no ferrite was generated, the balance between strength and ductility was lowered.
  • No. No. 19 used the steel type A in Table 1 whose components in the steel satisfy the requirements of the present invention, but is an example where the soaking temperature is low, ferrite is excessively generated and the total amount of (B + M) is also reduced. The desired hard layer was not obtained. Therefore, TS was lowered and ⁇ was also lowered.
  • No. No. 20 used the steel type A in Table 1 whose components in the steel satisfy the requirements of the present invention, but the air ratio in the oxidation furnace is low, the iron oxide film was not sufficiently generated, and the plating property was lowered. . Further, since the soft layer was not sufficiently formed, the bendability, ⁇ , and delayed fracture resistance were also deteriorated.
  • No. No. 22 is an example in which the steel type A in Table 1 whose components in the steel satisfy the requirements of the present invention is used, but the coiling temperature at the time of hot rolling is low and the air ratio in the oxidation furnace is low. Since the average depth of the internal oxide layer after cold rolling was shallow, the average depth d of the internal oxide layer after plating and the average depth D of the soft layer were also shallow. As a result, ⁇ , bendability, delayed fracture resistance, and plating properties were reduced.
  • No. 23 is an example in which the steel type A in Table 1 whose components in the steel satisfy the requirements of the present invention is used, but the coiling temperature at the time of hot rolling is low, and the average depth of the internal oxide layer after pickling and cold rolling Is shallow, the average depth d of the internal oxide layer after plating was also shallow. As a result, ⁇ , delayed fracture resistance, and plating properties were reduced.
  • No. No. 24 is an example in which the steel type A in Table 1 whose components in the steel satisfy the requirements of the present invention was used, but the average cooling rate after soaking was slow, and ferrite was excessively generated during cooling (B + M) As a result, the desired hard layer could not be obtained. As a result, ⁇ and bendability were lowered.
  • No. No. 28 is an example in which the steel type A in Table 1 whose components in the steel satisfy the requirements of the present invention was used, but the coiling temperature during hot rolling was low, and the average depth of the internal oxide layer after pickling and cold rolling Therefore, the average depth d of the internal oxide layer after plating and the average depth D of the soft layer were also reduced. As a result, the bendability, ⁇ , delayed fracture resistance, and plating properties decreased.
  • No. No. 29 used steel type A in Table 1 whose components in the steel satisfy the requirements of the present invention, but is an example of insufficient heat retention time, and the average depth of the internal oxide layer after pickling and cold rolling is shallow Therefore, the average depth d of the internal oxide layer after plating and the average depth D of the soft layer are also shallow. As a result, the bendability, ⁇ , delayed fracture resistance, and plating properties decreased.

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Abstract

L'invention fournit une tôle d'acier galvanisée à chaud par immersion et une tôle d'acier alliée galvanisée à chaud par immersion de 980MPa ou plus qui se révèlent excellentes en termes de propriétés de placage, de propriétés d'usinage, plus particulièrement concernant l'équilibre entre résistance et étirement, la flexibilité et l'extension d'orifice, et de résistance à la fracture différée. La tôle d'acier plaquée hautement résistante de l'invention possède une couche de plaquage à la surface d'une tôle d'acier de base, comprend des composants d'acier prédéfinis, et possède dans l'ordre depuis une interface entre la tôle d'acier de base et la couche de placage vers un côté tôle d'acier de base : une couche souple dont la dureté de Vickers, lorsque l'épaisseur de ladite tôle d'acier de base est représentée par t, satisfait 90% ou moins de la dureté de Vickers dans une partie t/4 de ladite tôle d'acier de base; et une couche dure comprenant dans une plage prédéfinie une martensite ainsi qu'une bainite, et une ferrite. La profondeur moyenne (D) de la couche souple est supérieure ou égale à 20μm, et la profondeur moyenne (d) d'une couche oxydée de partie interne est supérieure ou égale à 4μm et inférieure à la profondeur moyenne (D).
PCT/JP2016/050070 2015-01-09 2016-01-05 Tôle d'acier plaquée hautement résistante dotée d'excellentes propriétés de placage, d'usinage et de résistance à la fracture différée, et procédé de fabrication de celle-ci WO2016111275A1 (fr)

Priority Applications (4)

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MX2017009018A MX2017009018A (es) 2015-01-09 2016-01-05 Lámina de acero chapado de alta resistencia que tiene excelentes propiedades de chapado, trabajabilidad y mayor resistencia a las fracturas, y método para su producción.
KR1020177022030A KR101843705B1 (ko) 2015-01-09 2016-01-05 도금성, 가공성 및 내지연파괴특성이 우수한 고강도 도금 강판, 및 그의 제조 방법
CN201680005029.6A CN107109574A (zh) 2015-01-09 2016-01-05 镀覆性、加工性及耐延迟断裂特性优异的高强度钢板及其制造方法
US15/541,897 US20180010226A1 (en) 2015-01-09 2016-01-05 High-strength plated steel sheet having excellent plating properties, workability, and delayed fracture resistance, and method for producing same

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WO2017169836A1 (fr) * 2016-03-30 2017-10-05 株式会社神戸製鋼所 Tôle d'acier laminée à froid de haute résistance, tôle d'acier galvanisée par immersion à chaud de haute résistance et procédé de production d'une tôle d'acier laminée à froid de haute résistance et d'une tôle d'acier galvanisée par immersion à chaud de haute résistance
WO2017169837A1 (fr) * 2016-03-30 2017-10-05 株式会社神戸製鋼所 Tôle d'acier laminée à froid de haute résistance, tôle d'acier galvanisée par immersion à chaud de haute résistance, et procédé de production de tôle d'acier laminée à froid de haute résistance et de tôle d'acier galvanisée par immersion à chaud de haute résistance
WO2018151322A1 (fr) * 2017-02-20 2018-08-23 新日鐵住金株式会社 Tôle d'acier à résistance élevée
WO2018151331A1 (fr) * 2017-02-20 2018-08-23 新日鐵住金株式会社 Tôle d'acier haute résistance
WO2022230402A1 (fr) * 2021-04-27 2022-11-03 日本製鉄株式会社 Tôle d'acier allié galvanisé par immersion à chaud
KR20240027747A (ko) 2021-08-02 2024-03-04 닛폰세이테츠 가부시키가이샤 고강도 강판

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WO2011025042A1 (fr) * 2009-08-31 2011-03-03 新日本製鐵株式会社 Feuille d'acier galvanisé à chaud très résistante et son procédé de production
JP2011231367A (ja) * 2010-04-27 2011-11-17 Sumitomo Metal Ind Ltd 溶融亜鉛めっき鋼板およびその製造方法
WO2013047755A1 (fr) * 2011-09-30 2013-04-04 新日鐵住金株式会社 Feuille d'acier galvanisé par immersion à chaud et à haute résistance qui présente une excellente résistance aux chocs et procédé de production de cette dernière et feuille d'acier galvanisé par immersion à chaud alliée et à haute résistance et procédé de production correspondant
JP2013237924A (ja) * 2012-04-20 2013-11-28 Kobe Steel Ltd 化成処理性に優れた高強度冷延鋼板の製造方法
WO2015005191A1 (fr) * 2013-07-12 2015-01-15 株式会社神戸製鋼所 Tôle d'acier plaquée à haute résistance ayant des propriétés de placage, une aptitude à la mise en œuvre et une résistance à la rupture différée supérieures et procédé pour la production de celle-ci
WO2015146692A1 (fr) * 2014-03-28 2015-10-01 株式会社神戸製鋼所 Tôle d'acier allié galvanisée par immersion à chaud à haute résistance présentant une excellente résistance à la rupture différée et une excellente aptitude au façonnage ainsi que son procédé de production

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WO2017169836A1 (fr) * 2016-03-30 2017-10-05 株式会社神戸製鋼所 Tôle d'acier laminée à froid de haute résistance, tôle d'acier galvanisée par immersion à chaud de haute résistance et procédé de production d'une tôle d'acier laminée à froid de haute résistance et d'une tôle d'acier galvanisée par immersion à chaud de haute résistance
WO2017169837A1 (fr) * 2016-03-30 2017-10-05 株式会社神戸製鋼所 Tôle d'acier laminée à froid de haute résistance, tôle d'acier galvanisée par immersion à chaud de haute résistance, et procédé de production de tôle d'acier laminée à froid de haute résistance et de tôle d'acier galvanisée par immersion à chaud de haute résistance
WO2018151322A1 (fr) * 2017-02-20 2018-08-23 新日鐵住金株式会社 Tôle d'acier à résistance élevée
WO2018151331A1 (fr) * 2017-02-20 2018-08-23 新日鐵住金株式会社 Tôle d'acier haute résistance
EP3584348A4 (fr) * 2017-02-20 2020-08-05 Nippon Steel Corporation Tôle d'acier à résistance élevée
US11261505B2 (en) 2017-02-20 2022-03-01 Nippon Steel Corporation High strength steel sheet
US11408046B2 (en) 2017-02-20 2022-08-09 Nippon Steel Corporation High strength steel sheet
WO2022230402A1 (fr) * 2021-04-27 2022-11-03 日本製鉄株式会社 Tôle d'acier allié galvanisé par immersion à chaud
KR20240027747A (ko) 2021-08-02 2024-03-04 닛폰세이테츠 가부시키가이샤 고강도 강판

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