WO2007116913A1 - Very thin hard steel sheet and method for producing the same - Google Patents

Very thin hard steel sheet and method for producing the same Download PDF

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Publication number
WO2007116913A1
WO2007116913A1 PCT/JP2007/057575 JP2007057575W WO2007116913A1 WO 2007116913 A1 WO2007116913 A1 WO 2007116913A1 JP 2007057575 W JP2007057575 W JP 2007057575W WO 2007116913 A1 WO2007116913 A1 WO 2007116913A1
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Prior art keywords
phase
steel sheet
average
less
major axis
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PCT/JP2007/057575
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French (fr)
Japanese (ja)
Inventor
Hidekuni Murakami
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Nippon Steel Corporation
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Application filed by Nippon Steel Corporation filed Critical Nippon Steel Corporation
Priority to JP2008509867A priority Critical patent/JP5058978B2/en
Priority to CN2007800116843A priority patent/CN101415851B/en
Priority to ES07741011.6T priority patent/ES2575997T3/en
Priority to EP07741011.6A priority patent/EP2003221B1/en
Publication of WO2007116913A1 publication Critical patent/WO2007116913A1/en

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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • 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
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/06—Surface hardening
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties 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
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
    • C21D8/0426—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0447—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the heat treatment
    • C21D8/0457—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the heat treatment with diffusion of elements, e.g. decarburising, nitriding
    • 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
    • C21D9/48—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals deep-drawing sheets
    • 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
    • C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—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
    • C22C38/48—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
    • C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/40—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling foils which present special problems, e.g. because of thinness
    • 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
    • C21D2201/00—Treatment for obtaining particular effects
    • C21D2201/05—Grain orientation
    • 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
    • C21D2211/004—Dispersions; Precipitations
    • 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
    • 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
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
    • C21D8/0436—Cold rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties 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
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
    • C21D8/0442—Flattening; Dressing; Flexing

Definitions

  • the present invention relates to a thin steel plate having a thickness of 0.400 mm or less, including a surface-treated steel plate used for electrical equipment, electronic parts, building materials and metal containers, and a method for producing the same.
  • Thin steel plates with a thickness of 0.400mm or less are used in various applications such as electrical equipment, electronic parts, building materials and metal containers. Sheer ⁇ is progressing. As the material becomes thinner, the strength of the material that uses it will also decrease, so it is generally required to make the material thinner and harder.
  • One of the problems that manifests itself with such ultra-thin hard materials is deterioration of workability. Compared to thick materials used for automobiles, thin materials in particular tend to break immediately when constriction occurs, so uniform deformation is extremely important. This means that in the tensile test that is generally applied as an evaluation of the steel sheet properties, it is hardened without reducing the uniform elongation.
  • Patent Documents 1 to 3 have been disclosed in order to ensure workability particularly in steel plates for containers in which severe processing such as drawing, ironing, and tensile elongation is performed.
  • Patent Document 1 JP-A-2-118026
  • Patent Document 2 JP-A-3-257123
  • Patent Document 3 Japanese Patent Laid-Open No. 10-72640
  • An object of the present invention is to prevent breakage and constriction due to lack of uniform deformability, which are problems when using a hard ultrathin material.
  • uniform elongation is ensured by giving priority to the degradation of local elongation in the degradation of elongation due to the hardening of the material, and even when the total elongation is the same, the occurrence of local deformation (necking) is suppressed to a higher strain range. It is an issue.
  • An object of the present invention is to clarify the material conditions for this purpose, and to provide a steel sheet to which the material conditions are applied and a method for manufacturing the steel sheet.
  • the present inventors conducted research to disperse various second phases in the steel sheet.
  • the parent phase is an Fe ferrite phase, and the orientation of the second phase is arranged in a specific direction relative to the parent phase.
  • the second phase having an average major axis Z average minor axis ⁇ 2.0 of 0.05 / zm or more is contained in a volume fraction of 0.05% or more.
  • the hard ultrathin steel sheet according to (1) wherein the average major axis is 0.5 m or more, the average minor axis is not less than 0.0, and the average major axis Z average minor axis ⁇ 2.0.
  • the two phases are simple substances or composite compounds of oxides, sulfides, carbides, nitrides, and intermetallic compounds.
  • the hard ultrathin steel sheet according to (7) above having an average major axis of 0.5 ⁇ m or more and an average minor axis of 0 or more, and further, an average major axis Z an average minor axis ⁇ 2.
  • the second phase which is 0 is an oxide containing one or two of Fe, Mn, Si, Al, Cr, REM, Ti and Nb.
  • the second phase is a sulfide containing one or two of Ti, Mn, Cu, Ca, and REM.
  • the second phase having a minor axis of 0.1 ⁇ m or more and an average major axis Z average minor axis ⁇ 2.0 is a carbide containing one or two of Fe, Ti, Nb, Si, and Cr.
  • the hard ultrathin steel sheet according to (7) above having an average major axis of 0.5 m or more and an average minor axis of 0.1 ⁇ m or more, and an average major axis Z average minor axis ⁇ 2.
  • the second phase which is 0 is a nitride containing one or two of Fe, Ti, Nb, Al, B and Cr.
  • the hard ultra-thin steel sheet described in (7) above having an average major axis of 0.5 ⁇ m or more and an average minor axis of 0.1 ⁇ m or more, and an average major axis Z average minor axis ⁇ 2.
  • the second phase that is 0 is an intermetallic compound containing one or two of Fe, Ti, Nb, Al, Si, and Mn.
  • (21) A method for producing a hard ultrathin steel sheet according to (11) above, wherein after cold rolling, simultaneously with or after recrystallization annealing, in a temperature range of 600 to 700 ° C, ⁇ (nitriding time (Second)) * (nitridation temperature (° C)) ⁇ Z ⁇ (nitriding gas concentration (%))) * (cooling rate during nitriding (° CZ seconds)) ⁇ ⁇ 20 And increase the amount of N by more than 0.0002%.
  • the present invention relates to a thin steel plate having a thickness of 0.400 mm or less and a method for producing the thin steel plate.
  • a method for producing a part of the enameled steel plate a heat treatment is used to control the form of oxide.
  • the oxide stretching in the present invention is completely different from the oxide stretch as a limitation of hot rolling conditions in the enameled steel sheet. Furthermore, as an extension technique for limiting the hot rolling conditions in enameled steel sheets, it has been extremely difficult to obtain the idea of using drawn oxides in the thin steel sheets targeted by the steel of the present invention. These are described in detail below.
  • the content of acid oxide is suppressed as being extremely undesirable. This is because the base material itself is becoming thinner, and the deformation concentration around the oxide is very sensitive to the fracture of the base material.
  • a prominent example is the flange formability in the can making process, and the steel used in this application is manufactured at a very low level, with the amount of oxide strictly controlled.
  • the negative effect of the acid on thin materials is not limited to the acid itself, but if the drawn oxide like the enamel steel plate is crushed in the cold rolling process and voids are formed around it. In addition, the void exhibits an effect like a notch, and the deformability of the base material further deteriorates.
  • the thin material targeted by the steel of the present invention has the idea of improving its properties by utilizing oxides and, moreover, stretched oxides that are crushed by cold rolling to form voids around them. That itself was impossible in the past.
  • oxides are temporarily stretched during the hot rolling stage, but in the subsequent cold rolling process, the oxides are crushed and a large amount of empty space around the crushed acidic products. This is to create gaps, and in the final product, each acid product is isotropically crushed.
  • the acid oxide is stretched at the final stage, and as one proposal, a hot rolling process is used.
  • the oxide stretched by hot rolling remains stretched without being crushed after cold rolling and annealing, and it is necessary to maintain an anisotropic shape until the final product.
  • This difference is basically caused by the difference in the composition of the oxide if the hot rolling conditions are the same.
  • enameled steel plates are preferably combined with a relatively soft Mn-containing oxide and hard Nb and B-containing oxides to promote crushing.
  • the oxide is uniform rather than a composite of oxides having different compositions, so that deformation during cold rolling is uniform and fracture is avoided.
  • the steel of the present invention is held with the oxide stretched in a specific form, its work hardening behavior changes dramatically, and local deformation is strongly suppressed, so that even a thin steel plate has practical ductility. It was newly discovered and invented that it acts preferably.
  • FIG. 1 is a diagram for explaining a portion of a hard ultrathin steel plate according to the present invention in the thickness direction of the steel plate.
  • the C amount is set to C: 0.800% or less in order to avoid deterioration of workability. Preferably it is 0.100% or less, more preferably 0.060% or less.
  • the content is preferably 0.0050 to 0.040%, more preferably 0.0008 to 0.030%.
  • the C content required from the viewpoint of securing the strength may be low.
  • the N content is set to C: 0.800% or less in order to avoid deterioration of workability. Preferably it is 0.100% or less, more preferably 0.060% or less.
  • the content is preferably 0.0050 to 0.040%, more preferably 0.0008 to 0.030%.
  • the N content required from the viewpoint of securing the strength may be low.
  • N Necessary strength can be ensured even if it is 0.0050% or less, 0.0030% or less may be sufficient, and 0.0015% or less is also possible. In order to improve the r value and maintain high drawability, the N amount is The lower one is preferable.
  • Si may need to be 1.5% or less, and further 1.0% or less.
  • Si content is low. 0.5% or less, further 0.1% or less, and further 0.07% or less improves the moldability.
  • the preferable range of Mn is 0.05-: L 0%. More preferably, it is 0.15 to 0.8%, and more preferably 0.25 to 0.7%.
  • the content is set to 0.10% or less to inhibit the carburizing and nitriding properties of the steel sheet. In order to keep the moldability high, a lower P content is preferable. 0.05% or less, and even 0.01% or less improves moldability.
  • S degrades hot ductility and becomes a hindering factor for hot rolling, so it is made 0.10% or less.
  • Mn, Cu, Ti, REM, etc. when a large amount of Mn, Cu, Ti, REM, etc. is added and these sulfides are used as the second phase required in the present invention, a useful element with little deterioration in hot ductility is used. But there is. Therefore, the preferable range of S is set to 0.015 to 0.080%. More preferably, it is 0.025 to 0.070%, and more preferably 0.035 to 0.060%.
  • A1 is high, forging is difficult and surface wrinkles increase.
  • A1 is a strong deoxidizing element, when using an oxide as the second phase in the steel of the present invention, it is difficult for oxygen to remain in the steel.
  • it may be necessary to make the value 0.005% or less, 0.002% or less, and 0.001% or less.
  • Force depending on the type and amount of metal elements that form a compound with A1 In this case, it is preferably 1.0% or more, more preferably 1.5% or more, and even more preferably 2.0% or more.
  • O does not use an oxide as the second phase characteristic of the present invention.
  • it is preferably deoxidized with Al, Si, Ti, or the like to 0.010% or less. . This is because if the oxide in the steel has no effect on the effect of the present invention and becomes isotropic (spherical), it is easy to start a crack. Even when an oxide is used as a useful second phase, an excess of the oxide tends to cause cracking, so the content is made 0.20% or less.
  • it is 0.010-0.100%, More preferably, it is 0.020-0.080%, More preferably, it is 0.030-0.050%.
  • Ti raises the recrystallization temperature of the steel sheet, and significantly deteriorates the annealability of the ultrathin steel sheet which is the subject of the present invention. For this reason, it will be 4.00% or less.
  • a Ti compound is not used as the second phase, which is a feature of the present invention, it is not necessary to add Ti, and the content is made 0.04% or less, more preferably 0.01% or less.
  • Ti oxides, sulfides, carbides, nitrides, and intermetallic compounds can be used as the second phase characteristic of the present invention, and depending on the type and amount of elements forming the compound, 0.06 If it is more than%, the effect is fully exhibited. More preferably, it is 0.100% or more.
  • Nb has the same effect as Ti, raises the recrystallization temperature, and remarkably deteriorates the annealability of the ultrathin steel sheet targeted by the present invention. For this reason, it shall be 4.00% or less.
  • Nb compound is not used as the second phase, which is a feature of the present invention, it is not necessary to add Nb, and the content is made 0.04% or less, more preferably 0.01% or less.
  • oxides, sulfides, carbides, nitrides, and intermetallic compounds of Nb can be used as the second phase that is characteristic of the present invention, and depending on the type and amount of elements forming the compound, 0 The effect is fully demonstrated when it is over 06%. More preferably, it is 0.100% or more.
  • REM is a powerful element that has the same effect as Ti and Nb. To do.
  • the REM compound is not used as the second phase, which is a feature of the present invention, it is not necessary to add REM, and the content is made 0.04% or less, more preferably 0.01% or less.
  • REM oxides, sulfides, carbides, nitrides, and intermetallic compounds can be used as the second phase that is characteristic of the present invention, and depending on the type and amount of elements forming the compound, 0 If the value is 06% or more, the effect will be fully exerted. More preferably, it is 0.100% or more.
  • [0030] B also has the same effect as Ti and Nb.
  • the strength depending on the amount of addition When Ti and Nb are added at the same time as these elements for the purpose of forming carbides and nitrides as the second phase, the ability to form carbonitrides is small compared to Ti and Nb.
  • the recrystallization temperature of the steel sheet is increased, and the annealing passability of the ultrathin steel sheet targeted by the present invention is significantly deteriorated. Therefore, it is useful when the content of Ti and Nb is low.
  • the upper limit is set to 0.0300%.
  • the B compound When the B compound is not used as the second phase, which is a feature of the present invention, it is not necessary to add B, and it is 0.0010% or less, more preferably 0.0010% or less.
  • the oxides, carbides, nitrides, and intermetallic compounds of B can be used as the second phase that is characteristic of the present invention, and the force depending on the type and amount of the elements forming the compound is 0.0040% or more. The effect is fully demonstrated. More preferably, it is 0.0100% or more.
  • the recrystallization temperature will rise remarkably and the surface properties will be deteriorated by force, and workability and plating properties will deteriorate.
  • a metallic Cu phase or an intermetallic compound phase can be used as the second phase.
  • the preferable range is set to 0.10 to 4.00%. More preferably, it is 0.20 to 3.00%, and more preferably 0.30 to 2.50%.
  • Ca is a useful element because it is easy to obtain a stretched sulfide when a sulfide is used as the second phase.
  • a preferable range is 0.01 to 0.50%. More preferably, it is 0.05 to 30%.
  • Ni is an expensive element and should be 8.00% or less.
  • intermetalization such as Ni A1
  • a compound forming element As a compound forming element, it has a favorable effect on the dispersion of the second phase required in the present invention. 1.0% or more, depending on the type and amount of metal elements that form a compound with Ni Is preferably 1.5% or more, more preferably 2.0% or more.
  • Cr is also an expensive element and should be 20.00% or less.
  • a Cr compound is not used as the second phase, which is a feature of the present invention, it is not necessary to add Cr, and it is 0.06% or less, more preferably 0.02% or less.
  • Cr oxides, sulfides, carbides, nitrides, and intermetallic compounds can be used as the second phase that is characteristic of the present invention, and depending on the type and amount of elements forming the compound, 0 The effect is fully demonstrated when it is 10% or more. More preferably, it is 0.50% or more, more preferably 1.50% or more, and further preferably 2.50% or more.
  • the content of the elements other than the above is not particularly limited, but Sn, Sb, Mo, Ta, V, and W are added to each element in an amount of 0.1% to 10% in order to impart characteristics not specified in the present invention.
  • the total content of 0.50% or less does not impair the effects of the present invention.
  • the content of each element is preferably 0.010% or less and the total is preferably 0.050% or less. More preferably, it is TO. 0020% or less for each element, the total is 0.0050% or less, more preferably 0.0010% or less for each element, and the total is 0.0003% or less.
  • the second phase observation method limited in the present invention is not particularly limited.
  • the form can be directly observed with a physical measuring instrument capable of observing the micro area such as an electron microscope. Observation with a high-magnification optical microscope is possible if it is relatively large.
  • a physical measuring instrument capable of observing the micro area
  • Observation with a high-magnification optical microscope is possible if it is relatively large.
  • SEM scanning electron microscope
  • TEM transmission electron microscope
  • TEM transmission electron microscope
  • a residue obtained by dissolving the parent phase by electrolytic extraction may be observed.
  • the identification of the observed second phase is a force that can be performed by EDX or electron diffraction patterns, etc. You can use it.
  • the point is that the shape, size and number density of the second phase, and if necessary, the type can be determined by a method that is recognized as appropriate. Depending on the type, it is a composite of various phases, and it may be difficult to distinguish completely.
  • the effect of the present invention can be obtained by dispersing the second phase in a specific form regardless of the type, and therefore, the type of which cannot be determined is also included in the present invention. Volume fractions and number densities will increase if finer nitrides are taken into account using more sophisticated analytical instruments, but more than 0.02 m using normal level physical instruments The effect of the present invention can be discriminated if the target is of a size of.
  • the average major axis is 0.10 m or more
  • the average minor axis is 0.05 m or more
  • the average major axis Z the average minor axis ⁇ 2.0.
  • the phase is contained in a volume fraction of 0.05% or more.
  • the size is preferably about 0.20 m or more with respect to the average major axis, more preferably 0.50 m or more, more preferably 1.00 m or more, more preferably 2.00 / zm or more, more preferably 5. 00 / zm or more.
  • an excessively large second phase is present, it becomes the starting point of fracture at the initial stage of processing, and the ductility may be significantly deteriorated.
  • the average major axis The average minor axis Z is preferably 3.0 or more, more preferably 5.0 or more, and still more preferably 8.0 or more. Further, the volume fraction is preferably 0.1% or more, more preferably 0.3% or more, further preferably 1.0% or more, and further preferably 2.0% or more. However, if the amount of the second phase is too large, it becomes a starting point of fracture at the initial stage of processing, and the ductility may be remarkably deteriorated. More preferably, it is 10% or less.
  • the second phase in the present invention is harder than the Fe phase, which is the parent phase, when the steel sheet is deformed, the deformation of the parent phase occurs preferentially. Furthermore, since the deformation of the parent phase is constrained by the second phase, the work hardening of the parent phase becomes significant. For this reason, it is considered that the strain propagation is improved, the deformation continues while taking on the deformation in a wider area, and the uniform elongation becomes higher. When the anisotropic second phase is dispersed, the parent phase constraint is considered to be greater than the general isotropic second phase.
  • the second phase with strong anisotropy is weakly bonded to the parent phase, and its interface slips along with the deformation, and further deforms by generating many voids. It is thought that it is. For this reason, the deformation of the base metal itself is suppressed to a higher strain region, and it is considered that the uniform deformation continues.
  • the steel of the present invention has a large work hardening amount and at the same time the local deformability is often lowered, but the mechanism that can fully explain the phenomenon is not clear.
  • this main phase is Fe.
  • this main phase is assumed to be a ferrite phase of Fe, and its volume fraction is preferably 80% or more.
  • pearlite, bainite, martensite phase, etc. are known as the phase mainly composed of Fe.
  • the increase in strength is achieved by the dispersion of the second phase. This is because a soft and uniform phase is preferred from the viewpoint of workability.
  • the volume ratio is preferably 85% or more, more preferably 90% or more in order to avoid ductile deterioration due to the generation of an excessive second phase.
  • the orientation relationship between the second phase and the main phase is also an important requirement.
  • the force mentioned in the above mechanism The effect of the present invention is related to the fact that it is considered to be due to the combined state of the Fe phase and the second phase, and the direction of the average major axis of the second phase is the Fe in contact with the second phase. It is preferred that the phase is 100> orientation or 110> orientation. This orientation relationship can be detected by ordinary electron beam diffraction. [0039] Next, the type of the second phase itself will be described. In the present invention, a remarkable effect can be obtained when the second phase is a simple substance or a composite compound of an oxide, a sulfide, a carbide, a nitride, or an intermetallic compound.
  • oxide it must be an oxide containing one or two of Fe, Mn, Si, Al, Cr, REM, Ti, Nb, and in the case of oxide, Ti, Mn, Cu It is a sulfide containing one or two of Ca, REM, and in the case of carbide, it is a carbide containing one or two of Fe, Ti, Nb, Si, Cr, and nitride. In the case of a nitride containing one or two of Fe, Ti, Nb, Al, B, Cr, and in the case of an intermetallic compound, one or two of Fe, Ti, Nb, Al, Si, Mn It is an intermetallic compound containing seeds.
  • the pearlite structure observed in general steels that is, the layered structure of ferrite phase and cementite formed by transformation from the austenite phase at high temperature is excluded because the effect of the present invention cannot be obtained at all.
  • the transformation intermetallic compounds include NiAl, Ni Al, Ni (Al, Ti), Ni TiAl, Ni Ti, Ni Mo, Ni Mo, Ni Nb, Co W, F
  • Intermetallic compounds are compounds that are generally observed in steel materials and need not be special, but it is also possible to form special compounds in a form within the scope of the invention.
  • the types are not limited to the above, but only representative elements are listed.
  • the present invention includes a case where two or more types of second phases existing in steel are not limited to one type. These may be present independently or may form a composite compound. Furthermore, a phase that is not included in the present invention may be present at the same time.
  • the morphological characteristics of the second phase are important. However, it is true that there is a slight difference in the magnitude of the effect depending on the second phase formed. This difference depends on the type and amount of the second phase that can be generated in the steel sheet, the difference in form that can be controlled by the manufacturing conditions described later, and the second phase itself that is also related to the bonding state with the parent phase. The kind of influence is also conceivable.
  • the types of preferred second phases and the elements forming the second phase can be classified as follows.
  • the types are: intermetallic compounds> carbides ⁇ nitrides>oxides> sulfates. However, this is the same form and quantity This order is only an estimate, because it may be difficult to secure the quantity and control the form depending on the type of production method and the second phase. Yes.
  • the following can be said as the effect of each element.
  • oxides those containing Fe, Mn, and REM are preferred.
  • Si, Al, Cr, Ti, and Nb are less effective.
  • Mn, Ca, and REM are preferred.
  • Ti and Cu are less effective.
  • Thinitride distribution on the front and back sides the present invention also covers such steel sheets with different front and back layers. This is also a force that can obtain the effect of improving the uniform deformability aimed by the present invention on only one side.
  • the second phase characteristic of the present invention may be unevenly distributed in the plate thickness direction, which need not be uniformly distributed as a whole when considering the distribution in the plate thickness direction of the steel plate. . Rather, it is more convenient for the effect of the present invention if a multi-layer structure can be formed alternately in layers in the thickness direction, with layers having a large number of second phases and layers having a small number of second phases. Although this mechanism is not clear, it is thought that the amount of work hardening increases and the local deformation is suppressed when the layer with a large amount of the second phase and the layer with a small amount of each other restrain the deformation of the other.
  • volume fraction of the second phase (volume fraction at the plate thickness surface layer 1Z8) Z (volume fraction at the plate thickness center layer 1Z4) ⁇ 10, or
  • the number density is preferably (number density in the plate thickness surface layer 1Z8) Z (number density in the plate thickness center layer 1Z4) ⁇ 10.
  • the present invention is limited to being applied to a steel plate having a thickness of 0.4 OO mm or less.
  • a technique limited to only uniform elongation as in the technique of the present invention does not make sense. Because it disappears.
  • the present technology demonstrates its usefulness with an ultra-thin steel sheet having a thickness of preferably 0.250 mm or less, more preferably 0.200 mm or less, and even more preferably 0.150 mm or less.
  • the maximum strength is ⁇ 400 MPa and the Rockwell hardness is HR30T ⁇ 57, more preferably the maximum strength is ⁇ 450 MPa and the Rockwell hardness is HR30T ⁇ 61.
  • the steel of the present invention is characterized by uniform elongation Z local elongation ⁇ 1.0 in the tensile test using the JIS No. 5 test piece. This ratio is preferably 1.5 or more, more preferably 2.0 or more, further preferably 3.5 or more, and further preferably 5.0 or more. Further, as described above, the steel of the present invention is also characterized by a large amount of work hardening.
  • the yield stress Z maximum strength ⁇ 0.9, more preferably 0.8 or less, more preferably 0.7 or less, and even more preferably 0.6 or less.
  • One of the preferred forms is a hot rolling process in which the acid oxide is stretched by rolling into a preferred form. It is something to change. For this purpose, a certain amount of processing is required, and it is preferable that the thickness of the steel slab after completion of forging be 50 mm or more. More preferably, it is 150 mm or more. In order to make the oxide have an appropriate size after stretching, the size of the oxide before being stretched is preferably 10 m to 25 m. Too fine ones that are difficult to stretch are not preferable for the effects of the present invention because the spatial dispersion after rolling becomes linear.
  • the acidic product becomes stretched, partially crushed, and the moderately acicular shaped acidic product is placed in the steel plate at an appropriate interval. Will be dispersed. In order to appropriately stretch and disperse in this way, it is also important to control the strain rate in order to control the temperature control during hot rolling, the amount of strain in each temperature range, and the softening of the work-hardened steel.
  • the second The preferred form of the phase is achieved, basically by anisotropically growing the carbides sufficiently at high temperature, for a long time and under slow cooling while suppressing the formation of carbide precipitation nuclei at low C concentrations.
  • C that has entered the steel from the surface of the plate reaches the center of the plate thickness due to diffusion, and the above-mentioned double phase is developed.
  • the force is 500 or less, more preferably 200 or less, etc.
  • the conditions of the atmosphere including the type of carburizing gas are generally known.
  • the carburizing method is not limited to the gas carburizing shown here, and it is possible to apply a generally known carburizing method. An amount of 0.00002% or more is a force that seems to be very small as the amount of increase. Considering the amount of increase in the surface layer of the steel sheet in an ultrathin material, it is a sufficient amount for manifesting the effect of the invention.
  • the carburizing conditions are the conditions in the case of applying nitride by nitriding as the second phase, it is possible to obtain a preferable effect similar to that of carbide. That is, after cold rolling, simultaneously with recrystallization annealing, or after that, in the temperature range of 600 to 700 ° C, ⁇ (nitriding time (seconds)) * (nitriding temperature (° C)) ⁇ Z ⁇ (nitriding gas Concentration (%)) * (Cooling rate in nitriding treatment (° CZ sec)) ⁇ nitriding is performed under the condition of ⁇ 20, and the N content is increased by more than 0.0002%
  • nitriding method is not limited to the gas nitriding shown here, and a generally known nitriding method can be applied, as in the case of carburizing.
  • an intermetallic compound When an intermetallic compound is used as the second phase, formation may proceed mainly by growth of the intermetallic compound by slowly cooling from a state in which all or most of the intermetallic compound is dissolved.
  • Preferred in the present invention is convenient for obtaining the second phase form.
  • the cooling rate from 900 ° C to 500 ° C is cooled in 20 ° CZ seconds or less in the cooling process at a temperature of 900 ° C or higher, and the intermetallic compound is reduced in volume ratio. 2. Try to increase more than 0 times. If the temperature before the start of cooling is too low, intermetallic compounds Insufficient dissolution occurs and subsequent growth does not occur. On the other hand, if the cooling rate is too fast, the nucleation frequency of intermetallic compounds increases, and anisotropic growth does not occur, and isotropic intermetallic compounds are formed in high density.
  • re-rolling may be performed after recrystallization annealing in order to adjust hardness or plate thickness.
  • This rolling reduction has been put to practical use from a few percent close to the skin pass used for shape adjustment to 50% or more, which is the same as cold rolling.
  • the effects of the present invention are not impaired at all.
  • the rolling reduction is excessively high, the absolute value of the uniform force elongation that is natural is reduced.
  • the amount of work hardening in the uniform elongation region is also reduced, and this is not an inherently preferred method in view of applying the effect of the present invention.
  • it is 30% or less, more preferably 20% or less, preferably 10% or less, preferably 3% or less.
  • the effect of the present invention does not depend on the heat history and the manufacturing history before the annealing after the component adjustment.
  • Slabs for hot rolling are not limited to manufacturing methods such as the ingot method and continuous forging method, and do not depend on the heat history until hot rolling, so the slab reheating method and the forged slab are reheated.
  • the effect of the present invention can also be obtained by CC-DR method in which hot rolling is performed directly without making a thin slab without rough rolling.
  • the effect of the present invention can be obtained by two-phase rolling in which the finishing temperature is ⁇ + ⁇ two-phase region or continuous hot rolling in which a rough bar is joined and rolled regardless of hot rolling conditions.
  • the steel of the present invention when used as a material having a welded portion, it is particularly preferable because uniform deformation at the heat-affected zone can be improved and necking can be suppressed.
  • the steel sheet of the present invention includes a case where it is used after being subjected to some surface treatment. If it is within the scope of the present invention, it is not damaged by the surface treatment by application.
  • surface treatment For metal plating, tin, chromium (tin-free), Ni, zinc, aluminum, etc. are applied as usual.
  • the effects of the present invention can be obtained with respect to an original sheet for a laminated steel sheet coated with an organic film that has been used in recent years.
  • Average major axis The second phase satisfying the condition that the average major axis is 0.10 m or more, the average minor axis is 0.05 / zm or more, the average major axis Z the average minor axis ⁇ 2.0 The average value when measuring a sufficient number so that there is no.
  • Average major axis Z Average minor axis Ratio of “average major axis” and “average minor axis”. It becomes an index indicating the degree of anisotropy of V, which is the root of the invention effect.
  • “Contained element” an element detected from the second phase showing the characteristics of the present invention.
  • Orientation The relationship between the direction of the average major axis of the second phase and the crystal orientation of the main phase in contact with the second phase. When the orientation is related, the crystal orientation of the main phase is indicated.
  • “Flange formability” Prepare 10,000 barrels of 3-piece can body that is made by rounding a flat plate into a cylindrical shape and welding. For these, flange molding is performed using a mold. As a result, if all can flanges can be molded without breaking, it will be accepted. If even one can breaks, it will be rejected.
  • Example 1 Table 2 shows the experimental results when the second phase is an oxide.
  • the form of the oxide was controlled mainly by the oxide size according to the forging conditions and the stretching amount according to the hot rolling conditions.
  • Acid The “number density” of the object was determined by cross-sectional observation with SEM. It can be confirmed that good uniform elongation can be obtained by controlling the state of the oxide within the range of the present invention.
  • Table 3 shows the experimental results when the second phase is a sulfate.
  • the form of the sulfide was controlled mainly by the sulfide size according to the forging conditions and the drawing amount by the hot rolling conditions.
  • the “number density” of the sulfide was determined by TEM observation. It can be confirmed that good uniform elongation can be obtained by controlling the state of the sulfide within the range of the present invention.
  • Example 3 shows the experimental results when the second phase is carbide or nitride.
  • the carbide or nitride morphology was controlled primarily by carburizing or nitriding conditions.
  • all the “base plates” are steel plates recrystallized and annealed at 700 ° C.
  • the characteristics are also shown for a material that has been hardened to the same degree as a carburized or nitrided plate by re-rolling without carburizing and nitriding. Carbide or nitride was observed at the plate thickness 1Z8 position and the plate thickness center.
  • the “number density” of carbide or nitride was determined by SEM observation of the residue when the plate thickness surface layer 1Z8 or plate thickness center layer 1Z4 was electrolyzed.
  • the values related to “volume fraction”, “number density”, and main phase in the second phase in Table 4 are for the plate thickness surface layer 1Z8. It can be confirmed that good uniform elongation is obtained by controlling the state of the carbide or nitride within the range of the present invention.
  • Table 5 shows the experimental results when the second phase was an intermetallic compound.
  • the intermetallic compound is Ni A1, and its form is mainly the solution due to recrystallization annealing conditions, especially the annealing temperature.
  • the present invention it is possible to obtain a hard ultrathin material having high uniform elongation even with the same strength and the same total elongation, and suppressing the occurrence of local deformation (necking) to a higher strain range.

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Abstract

Disclosed is a very thin hard steel sheet having a thickness of not more than 0.400 mm and containing, in mass %, 0-0.800% (inclusive) of C, 0-0.600% (inclusive) of N, 0-2.0% (inclusive) of Si, 0-2.0% (inclusive) of Mn, 0-0.10% (inclusive) of P, 0-0.100% (inclusive) of S, 0-3.0% (inclusive) of Al and 0-0.200% (inclusive) of O. Secondary phases having an average length of not less than 0.10 μm and an average breadth of not less than 0.05 μm, while satisfying the following relation: average length/average breadth ≥ 2.0 are contained in the steel sheet at a volume fraction of not less than 0.05%.

Description

硬質極薄鋼板およびその製造方法  Hard ultra-thin steel plate and manufacturing method thereof
技術分野  Technical field
[0001] 本発明は、電機機器、電子部品、建材や金属容器に利用される表面処理鋼板を含 む、板厚が 0. 400mm以下の薄手鋼板と、その製造方法とに関する。  [0001] The present invention relates to a thin steel plate having a thickness of 0.400 mm or less, including a surface-treated steel plate used for electrical equipment, electronic parts, building materials and metal containers, and a method for producing the same.
本出願は、特願 2006— 102766号を基礎出願とし、その内容を取り込むものとす る。  This application is based on Japanese Patent Application No. 2006-102766, and the contents thereof are incorporated.
背景技術  Background art
[0002] 板厚が 0. 400mm以下の薄手の鋼板は、電機機器、電子部品、建材や金属容器 などの様々な用途で用いられているが、素材の低コストィ匕のために、鋼板のさらなる 薄手ィ匕が進行している。素材が薄くなると、それを使用した部材の強度も低下してし まうため、一般的には薄手化と同時に素材の硬質化も要求される。このような極薄硬 質材料で顕在化する問題の一つに、加工性の劣化がある。特に薄い材料は、自動 車用などで使用される厚手材と比較すると、くびれが発生すると直ちに破断にいたる ため、均一な変形をさせることが極めて重要になる。これは、鋼板特性の評価として 一般的に適用されている引張試験においては、均一伸びを落とさずに、硬質化する ことを意味する。これらの薄手材料の中でも、特に、絞り、しごき、引張伸びなどの厳 しい加工が行なわれる容器用鋼板では、加工性を確保するため、特許文献 1〜3の ような方法が開示されている。  [0002] Thin steel plates with a thickness of 0.400mm or less are used in various applications such as electrical equipment, electronic parts, building materials and metal containers. Sheer 匕 is progressing. As the material becomes thinner, the strength of the material that uses it will also decrease, so it is generally required to make the material thinner and harder. One of the problems that manifests itself with such ultra-thin hard materials is deterioration of workability. Compared to thick materials used for automobiles, thin materials in particular tend to break immediately when constriction occurs, so uniform deformation is extremely important. This means that in the tensile test that is generally applied as an evaluation of the steel sheet properties, it is hardened without reducing the uniform elongation. Among these thin materials, methods such as Patent Documents 1 to 3 have been disclosed in order to ensure workability particularly in steel plates for containers in which severe processing such as drawing, ironing, and tensile elongation is performed.
[0003] しかし、これらの方法は、特に均一伸びに注目したものではなぐ延性 (全伸び）が 高いとは言え、局部伸びによって延性を高めている面が多い。よって、実用において は、破断やくびれによる表面性状の欠陥など、本願の課題を解決するには至ってい ない。  [0003] However, although these methods have high ductility (total elongation) that is not particularly focused on uniform elongation, there are many aspects in which ductility is enhanced by local elongation. Therefore, in practical use, the problems of the present application such as surface texture defects due to breakage and constriction have not been solved.
特許文献 1 :特開平 2—118026号  Patent Document 1: JP-A-2-118026
特許文献 2：特開平 3— 257123号  Patent Document 2: JP-A-3-257123
特許文献 3：特開平 10— 72640号  Patent Document 3: Japanese Patent Laid-Open No. 10-72640
発明の開示 発明が解決しょうとする課題 Disclosure of the invention Problems to be solved by the invention
[0004] 本発明は、硬質極薄手材を使用する際に問題となる、均一変形性の不足による破 断、くびれの発生抑止を課題としている。すなわち、材料の硬質化に伴う伸びの劣化 において、局部伸びの劣化を優先させることで均一伸びを確保し、同じ全伸びであ つても、局部変形 (くびれ)の発生をより高歪域まで抑えることを課題としている。そし て、本発明は、このための材料条件を明確にし、それを適用した鋼板およびその製 造方法を提供することを目的とする。 [0004] An object of the present invention is to prevent breakage and constriction due to lack of uniform deformability, which are problems when using a hard ultrathin material. In other words, uniform elongation is ensured by giving priority to the degradation of local elongation in the degradation of elongation due to the hardening of the material, and even when the total elongation is the same, the occurrence of local deformation (necking) is suppressed to a higher strain range. It is an issue. An object of the present invention is to clarify the material conditions for this purpose, and to provide a steel sheet to which the material conditions are applied and a method for manufacturing the steel sheet.
課題を解決するための手段  Means for solving the problem
[0005] 本発明者らは、鋼板を硬質化するために、鋼板中に様々な第二相を分散させる研 究を行なった。これは、いわゆる析出強化や組織強化の範疇に属するもので、第二 相を分散させれば材質が硬質化し、当然の結果として延性を劣化させるものである 力 実験を重ねるうち、特定の形態をもつ第二相を鋼板中に分散させた場合は、均 一伸びの劣化を抑えたまま硬質ィ匕できることを知見した。さらに、第二相の形態、量、 および種類と、好ま 、特性が得られる鋼板材質の範囲にっ 、ても詳細に検討し、 本発明に至った。本発明の要旨を以下に示す。 [0005] In order to harden the steel sheet, the present inventors conducted research to disperse various second phases in the steel sheet. This belongs to the category of so-called precipitation strengthening and structure strengthening, and if the second phase is dispersed, the material becomes hard and naturally deteriorates the ductility. It has been found that when the second phase is dispersed in the steel sheet, it can be hardened while suppressing deterioration of uniform elongation. Further, even in the form, amount, and type of the second phase, and preferably the range of the steel plate material from which the characteristics can be obtained, the present invention has been studied in detail. The gist of the present invention is shown below.
(1)第二相の形態の制御。異方性の強い、針状ものとする。  (1) Control of the form of the second phase. Needle-shaped with strong anisotropy.
(2)第二相のサイズの制御。一般的な析出物に比較して大きくする。  (2) Control of the size of the second phase. It is larger than general precipitates.
(3)第二相の数密度の制御。比較的まばらに分散させる。  (3) Control of the number density of the second phase. Disperse relatively sparsely.
(4)母相を Feフェライト相とし、第二相の方位を母相に対して特定の向きに配置させ る。  (4) The parent phase is an Fe ferrite phase, and the orientation of the second phase is arranged in a specific direction relative to the parent phase.
[0006] 本発明者等は、上記の技術思想に基づ 、て鋭意検討の結果、本発明に想到した。  [0006] The inventors of the present invention have come up with the present invention as a result of intensive studies based on the above technical idea.
その要旨とするところは下記内容の通りである。  The summary is as follows.
(1)板厚が 0. 400mm以下の硬質極薄鋼板であって、 質量％で、 C : 0%以上かつ 0. 800%以下、？^ : 0%以上かっ0. 600%以下、 Si : 0%以上かつ 2. 0%以下、 Mn : 0%以上かつ 2. 0%以下、 P : 0%以上かつ 0. 10%以下、 S : 0%以上かつ 0. 100 %以下、 A1: 0%以上かつ 3. 0%以下、 0 : 0%以上かっ0. 200%以下を含有し、平 均長径が 0. 10 m以上かつ平均短径が 0. 05 /z m以上で、さらに平均長径 Z平均 短径≥2. 0である第二相が、体積分率で、 0. 05%以上含有されている。 (2)上記（1)に記載の硬質極薄鋼板であって、 Ti: 0%以上かつ 4. 00%以下 (0を 含む）、 Nb : 0%以上かつ 4. 00%以下（0を含む）、 REM : 0%以上かつ 4. 00%以 下（0を含む）、 B : 0%以上かつ 0. 0300%以下（0を含む）、 Cu: 0%以上かつ 8. 00 %以下（0を含む）、 Ca: 0%以上かつ 1. 00%以下（0を含む）、 Ni: 0%以上かつ 8. 00%以下（0を含む）、 Cr: 0%以上かつ 20. 00%以下（0を含む）、の一種または二 種以上をさらに含有する。 (1) Hard ultra-thin steel sheet with a thickness of 0.400 mm or less, in mass%, C: 0% or more and 0.88% or less? ^: 0% to 600%, Si: 0% to 2.0%, Mn: 0% to 2.0%, P: 0% to 0.10%, S: 0% or more and 0.100% or less, A1: 0% or more and 3.0% or less, 0: 0% or more and 0.20% or less, average major axis is 0.10 m or more and average minor axis The second phase having an average major axis Z average minor axis ≥2.0 of 0.05 / zm or more is contained in a volume fraction of 0.05% or more. (2) The hard ultra-thin steel sheet described in (1) above, Ti: 0% to 4.00% (including 0), Nb: 0% to 4.00% (including 0) ), REM: 0% or more and 4.00% or less (including 0), B: 0% or more and 0.0300% or less (including 0), Cu: 0% or more and 8.00% or less (0 Ca: 0% or more and 1.00% or less (including 0), Ni: 0% or more and 8.00% or less (including 0), Cr: 0% or more and 20.00% or less (including 0) 0)), or one or more of them.
(3)上記（1)に記載の硬質極薄鋼板であって、平均長径が 0. 5 m以上かつ平均 短径が 0. 1 m以上で、さらに平均長径 Z平均短径≥ 2. 0である第二相の数密度 力 0. 01個 Z μ m2以上である。 (3) The hard ultra-thin steel sheet described in (1) above, wherein the average major axis is 0.5 m or more, the average minor axis is 0.1 m or more, and the average major axis Z average minor axis ≥2.0. Number density force of a certain second phase is 0.01. Z μm 2 or more.
(4)上記（1)に記載の硬質極薄鋼板であって、平均長径が 0. 5 m以上かつ平均 短径が 0. 1 m以上で、さらに平均長径 Z平均短径≥ 2. 0である第二相の数密度 力 0. 001個 Z μ m3以上である。 (4) The hard ultra-thin steel sheet described in (1) above, wherein the average major axis is 0.5 m or more, the average minor axis is 0.1 m or more, and the average major axis Z average minor axis ≥2.0. Number density force of some second phase 0.001 piece Z μm 3 or more.
[0007] (5)上記（1)に記載の硬質極薄鋼板であって、主相が Feのフェライト相でかつ体積 率が 80%以上である。  [0007] (5) The hard ultrathin steel sheet according to (1) above, wherein the main phase is a ferrite phase of Fe and the volume fraction is 80% or more.
(6)上記（1)に記載の硬質極薄鋼板であって、平均長径が 0. 5 m以上かつ平均 短径が 0. 1 m以上で、さらに平均長径 Z平均短径≥ 2. 0である第二相の平均長 径の方向がこの第二相が接している Fe相のく 100 >方位またはく 110 >方位であ る。  (6) The hard ultra-thin steel sheet described in (1) above, wherein the average major axis is 0.5 m or more, the average minor axis is 0.1 m or more, and the average major axis Z average minor axis ≥2.0. The direction of the average major axis of a certain second phase is either 100> orientation or 110> orientation of the Fe phase in contact with this second phase.
(7)上記（1)に記載の硬質極薄鋼板であって、平均長径が 0. 5 m以上かつ平均 短径が 0. 以上で、さらに平均長径 Z平均短径≥ 2. 0である第二相が、酸ィ匕物 、硫化物、炭化物、窒化物、金属間化合物の単体または複合ィ匕合物である。  (7) The hard ultrathin steel sheet according to (1), wherein the average major axis is 0.5 m or more, the average minor axis is not less than 0.0, and the average major axis Z average minor axis ≥2.0. The two phases are simple substances or composite compounds of oxides, sulfides, carbides, nitrides, and intermetallic compounds.
[0008] (8)上記（7)に記載の硬質極薄鋼板であって、平均長径が 0. 5 μ m以上かつ平均 短径が 0. 以上で、さらに平均長径 Z平均短径≥ 2. 0である第二相が、 Fe、 M n、 Si、 Al、 Cr、 REM, Ti、 Nbの一種または二種を含有する酸化物である。  [0008] (8) The hard ultrathin steel sheet according to (7) above, having an average major axis of 0.5 μm or more and an average minor axis of 0 or more, and further, an average major axis Z an average minor axis ≥ 2. The second phase which is 0 is an oxide containing one or two of Fe, Mn, Si, Al, Cr, REM, Ti and Nb.
(9)上記（7)に記載の硬質極薄鋼板であって、平均長径が 0. 5 m以上かつ平均 短径が 0. 1 μ m以上で、さらに平均長径 Z平均短径≥ 2. 0である第二相が、 Ti、 M n、 Cu、 Ca、 REMの一種または二種を含有する硫化物である。  (9) The hard ultra-thin steel sheet according to (7), wherein the average major axis is 0.5 m or more and the average minor axis is 0.1 μm or more, and the average major axis Z average minor axis ≥2.0 The second phase is a sulfide containing one or two of Ti, Mn, Cu, Ca, and REM.
(10)上記（7)に記載の硬質極薄鋼板であって、平均長径が 0. 5 μ m以上かつ平均 短径が 0. 1 μ m以上で、さらに平均長径 Z平均短径≥ 2. 0である第二相が、 Fe、 Ti 、 Nb、 Si、 Crの一種または二種を含有する炭化物である。 (10) The hard ultra-thin steel sheet according to (7), wherein the average major axis is 0.5 μm or more and the average The second phase having a minor axis of 0.1 μm or more and an average major axis Z average minor axis ≥2.0 is a carbide containing one or two of Fe, Ti, Nb, Si, and Cr.
[0009] (11)上記（7)に記載の硬質極薄鋼板であって、平均長径が 0. 5 m以上かつ平均 短径が 0. 1 μ m以上で、さらに平均長径 Z平均短径≥ 2. 0である第二相が、 Fe、 Ti 、 Nb、 Al、 B、 Crの一種または二種を含有する窒化物である。 [0009] (11) The hard ultrathin steel sheet according to (7) above, having an average major axis of 0.5 m or more and an average minor axis of 0.1 μm or more, and an average major axis Z average minor axis ≥ 2. The second phase which is 0 is a nitride containing one or two of Fe, Ti, Nb, Al, B and Cr.
(12)上記（7)に記載の硬質極薄鋼板であって、平均長径が 0. 5 μ m以上かつ平均 短径が 0. 1 μ m以上で、さらに平均長径 Z平均短径≥ 2. 0である第二相が、 Fe、 Ti 、 Nb、 Al、 Si、 Mnの一種または二種を含有する金属間化合物である。  (12) The hard ultra-thin steel sheet described in (7) above, having an average major axis of 0.5 μm or more and an average minor axis of 0.1 μm or more, and an average major axis Z average minor axis ≥ 2. The second phase that is 0 is an intermetallic compound containing one or two of Fe, Ti, Nb, Al, Si, and Mn.
(13)上記（1)に記載の硬質極薄鋼板であって、平均長径が 0. 以上かつ平均 短径が 0. 1 m以上で、さらに平均長径 Z平均短径≥ 2. 0である第二相の体積率 力 （板厚表層 1Z8での体積率) / (板厚中心層 1Z4での体積率）≥ 10である。  (13) The hard ultra-thin steel sheet according to (1) above, wherein the average major axis is not less than 0, the average minor axis is not less than 0.1 m, and the average major axis Z average minor axis ≥2.0. Volume ratio of two phases Force (Volume ratio at plate thickness surface layer 1Z8) / (Volume ratio at plate thickness center layer 1Z4) ≥10.
[0010] (14)上記（1)に記載の硬質極薄鋼板であって、平均長径が 0. 5 m以上かつ平均 短径が 0. 1 m以上で、さらに平均長径 Z平均短径≥ 2. 0である第二相の数密度 力 （板厚表層 1Z8での数密度) Z (板厚中心層 1Z4での数密度）≥ 10である。 [0010] (14) The hard ultrathin steel sheet according to (1) above, having an average major axis of 0.5 m or more and an average minor axis of 0.1 m or more, and an average major axis Z average minor axis ≥ 2 The number density of the second phase, which is 0 (number density at the plate thickness surface layer 1Z8) Z (number density at the plate thickness center layer 1Z4) ≥10.
(15)上記（1)に記載の硬質極薄鋼板であって、幅 25mmで長さ 60mmの平行部を 有する引張試験片を用いて、評点間距離を 50mm、変形速度を 5mmZ分とする引 張試験における最高強度≥350MPa、かつ、ロックウェル硬度 HR30T≥ 54である。(15) The hard ultra-thin steel sheet described in (1) above, using a tensile test piece having a parallel part of 25 mm in width and 60 mm in length, with a distance between ratings of 50 mm and a deformation rate of 5 mmZ. Maximum strength in tension test ≥350 MPa and Rockwell hardness HR30T≥54.
(16)上記（1)に記載の硬質極薄鋼板であって、幅 25mmで長さ 60mmの平行部を 有する引張試験片を用いて、評点間距離を 50mm、変形速度を 5mmZ分とする引 張試験において、均一伸び Z局部伸び≥1. 0である。 (16) The hard ultra-thin steel sheet described in (1) above, using a tensile test piece having a parallel part of 25 mm in width and 60 mm in length, with a distance between ratings of 50 mm and a deformation rate of 5 mmZ. In the tension test, uniform elongation Z local elongation ≥1.0.
[0011] (17)上記（1)に記載の硬質極薄鋼板であって、幅 25mmで長さ 60mmの平行部を 有する引張試験片を用いて、評点間距離を 50mm、変形速度を 5mmZ分とする引 張試験において、降伏応力 Z最高強度≤0. 9である。  [0011] (17) The hard ultra-thin steel plate described in (1) above, using a tensile test piece having a parallel part of 25 mm in width and 60 mm in length, with a distance between grades of 50 mm and a deformation rate of 5 mmZ Yield stress Z maximum strength ≤ 0.9.
(18)上記（8)に記載の硬質極薄鋼板を製造する方法であって、厚さ 50mm以上か っ鋼片中の酸化物の平均直径が 10 μ m〜25 μ mの鋼片を 600°C以上の熱間で圧 延加工する際に、 1000°C以上かつ歪速度 1Z秒以上の条件での真歪の総和が 0. 4以上の圧延を行なった後に、 1000°C以下かつ歪速度 10Z秒以上の条件での真 歪の総和が 0. 7以上の圧延を行なう。 (19)上記（9)に記載の硬質極薄鋼板を製造する方法であって、厚さ 50mm以上か っ鋼片中の硫化物の平均直径が 10 μ m〜25 μ mの鋼片を 600°C以上の熱間で圧 延加工する際に、 1000°C以上かつ歪速度 1Z秒以上の条件での真歪の総和が 0. 4以上の圧延を行なった後に、 1000°C以下かつ歪速度 10Z秒以上の条件での真 歪の総和が 0. 7以上の圧延を行なう。 (18) A method for producing a hard ultrathin steel sheet as described in (8) above, wherein a steel slab having an average oxide diameter of 10 to 25 μm in a steel slab having a thickness of 50 mm or more is 600 When rolling at a temperature higher than or equal to ° C, after rolling with a total true strain of 0.4 or higher at 1000 ° C or higher and a strain rate of 1 Zsec or higher, Roll with a total true strain of 0.7 or more under the condition of speed 10Z seconds or more. (19) A method for producing a hard ultrathin steel sheet as described in (9) above, wherein a steel slab having an average diameter of sulfide in a steel slab of 50 mm or more in thickness of 10 μm to 25 μm is 600 When rolling at a temperature higher than or equal to ° C, after rolling with a total true strain of 0.4 or higher at 1000 ° C or higher and a strain rate of 1 Zsec or higher, Roll with a total true strain of 0.7 or more under the condition of speed 10Z seconds or more.
[0012] (20)上記（10)に記載の硬質極薄鋼板を製造する方法であって、冷延後、再結晶焼 鈍と同時またはその後に、 600〜700°Cの温度域で、 { (浸炭時間（秒)） * (浸炭温 度 (°C)MZ{ (浸炭性ガス濃度 (％；) ) * (浸炭処理での冷却速度 (°CZ秒)） }≥20な る条件で浸炭処理を行い、 C量を 0. 0002%以上増加させる。 [0012] (20) A method for producing a hard ultrathin steel sheet as described in (10) above, in the temperature range of 600 to 700 ° C after cold rolling, simultaneously with or after recrystallization annealing, (Carburizing time (sec)) * (Carburizing temperature (° C) MZ {(Carburizing gas concentration (%;))) * (Cooling rate in carburizing treatment (° CZ sec)) Process and increase the C content by 0.0002% or more.
(21)上記（11)に記載の硬質極薄鋼板を製造する方法であって、冷延後、再結晶焼 鈍と同時またはその後に、 600〜700°Cの温度域で、 { (窒化時間（秒)） * (窒化温 度 (°C)) }Z{ (窒化性ガス濃度（％) ) * (窒化処理での冷却速度 (°CZ秒)） }≥20な る条件で窒化処理を行い、 N量を 0. 0002%以上増加させる。  (21) A method for producing a hard ultrathin steel sheet according to (11) above, wherein after cold rolling, simultaneously with or after recrystallization annealing, in a temperature range of 600 to 700 ° C, {(nitriding time (Second)) * (nitridation temperature (° C))} Z {(nitriding gas concentration (%))) * (cooling rate during nitriding (° CZ seconds))} ≥20 And increase the amount of N by more than 0.0002%.
(22)上記（12)に記載の硬質極薄鋼板を製造する方法であって、鋼板製造工程に お!、て、 900°C以上の温度からの冷却過程にお!、て 900°Cから 500°Cまでの冷却速 度を 20°CZ秒以下で冷却し、金属間化合物を体積率で 2. 0倍以上増加させる。 なお。本明細書中における記号" * "は、かけ算（X )を示す。  (22) A method for producing a hard ultrathin steel plate as described in (12) above, in the steel plate production process, in the cooling process from 900 ° C or higher! Cool the cooling rate to 500 ° C within 20 ° CZ seconds and increase the intermetallic compound by 2.0 times or more in volume ratio. Note that. The symbol “*” in the present specification indicates multiplication (X).
[0013] なお、本発明は、板厚が 0. 400mm以下の薄手鋼板と、その製造方法とに関する ものであるが、ほうろう鋼板の一部の製法として、酸化物の形態を制御するために熱 延条件を限定する従来技術が存在して 、る。 [0013] The present invention relates to a thin steel plate having a thickness of 0.400 mm or less and a method for producing the thin steel plate. As a method for producing a part of the enameled steel plate, a heat treatment is used to control the form of oxide. There is a conventional technique for limiting the rolling conditions.
しかし、本発明における酸化物延伸と、ほうろう鋼板における熱延条件の限定として の酸ィ匕物延伸とは全く異なったものである。さらに言うと、ほうろう鋼板における熱延 条件の限定の延長技術として、本発明鋼が対象とする薄手鋼板で延伸酸化物を活 用する発想を得ることそのものが極めて困難であった。これらについて、以下に詳細 に説明する。  However, the oxide stretching in the present invention is completely different from the oxide stretch as a limitation of hot rolling conditions in the enameled steel sheet. Furthermore, as an extension technique for limiting the hot rolling conditions in enameled steel sheets, it has been extremely difficult to obtain the idea of using drawn oxides in the thin steel sheets targeted by the steel of the present invention. These are described in detail below.
[0014] 一般的に、本発明のような薄手鋼板では、酸ィ匕物は極めて好ましくないものとして その含有が抑制されている。これは、母材そのものが薄くなつているため、酸化物周 囲への変形集中が母材の破断に非常に敏感に作用するためである。 顕著な例としては、製缶加工でのフランジ成形性であり、この用途に用いられる鋼 材は、酸化物量が厳密に管理され、非常に低いレベルで製造されている。薄手材料 への酸ィ匕物の悪影響は、酸ィ匕物そのものにとどまらず、ほうろう鋼板のように延伸した 酸ィ匕物が冷延工程で破砕してその周囲に空隙を形成してしまうと、空隙が切り欠きの ような効果を発揮し、母材の変形能がさらに劣化してしまう。 [0014] Generally, in the thin steel plate as in the present invention, the content of acid oxide is suppressed as being extremely undesirable. This is because the base material itself is becoming thinner, and the deformation concentration around the oxide is very sensitive to the fracture of the base material. A prominent example is the flange formability in the can making process, and the steel used in this application is manufactured at a very low level, with the amount of oxide strictly controlled. The negative effect of the acid on thin materials is not limited to the acid itself, but if the drawn oxide like the enamel steel plate is crushed in the cold rolling process and voids are formed around it. In addition, the void exhibits an effect like a notch, and the deformability of the base material further deteriorates.
このため、本発明鋼が対象とする薄手材料では、酸化物、ましてや、冷延で破砕し て周囲に空隙を形成するような延伸酸ィ匕物を活用して特性を向上させるという着想を 得ること自体が、従来では不可能であった。  For this reason, the thin material targeted by the steel of the present invention has the idea of improving its properties by utilizing oxides and, moreover, stretched oxides that are crushed by cold rolling to form voids around them. That itself was impossible in the past.
[0015] また、ほうろう鋼板の製造方法と本発明との間における技術的相違点として、以下 のような事項が挙げられる。 [0015] Further, as technical differences between the method for producing an enameled steel sheet and the present invention, the following matters can be cited.
まず、ほうろう鋼板の製造では、熱延段階で一時的に酸化物を延伸させるものの、 それはその後の冷延工程で酸ィ匕物を破砕し、破砕された酸ィ匕物の周囲に多量の空 隙を生成するためであり、最終製品ではそれぞれの酸ィ匕物は細力べ破砕された等方 的な形状となる。  First, in the manufacture of enameled steel sheets, oxides are temporarily stretched during the hot rolling stage, but in the subsequent cold rolling process, the oxides are crushed and a large amount of empty space around the crushed acidic products. This is to create gaps, and in the final product, each acid product is isotropically crushed.
[0016] これに対し本発明では、酸ィ匕物が最終段階で延伸したものである必要があり、その 一方案として熱延工程を活用している。つまり、熱延で延伸させた酸化物は、冷延、 焼鈍後も破砕せずに延伸したままであり、最終製品まで異方性を持った形状を維持 させることが必要となる。この差は、熱延条件が同じであれば、基本的には酸化物の 組成の違いで生ずる。すなわち、ほうろう鋼板では、比較的軟質な Mn含有の酸化物 と、硬質な Nb, B含有の酸ィ匕物とが複合した形態になっていることが破砕促進に好ま しく作用する。一方、本発明鋼では、酸化物が、組成が異なる酸ィ匕物が複合したもの ではなぐ均質なものとすることで、冷延時の変形も均一となり破砕を回避することが 好ましい。  [0016] On the other hand, in the present invention, it is necessary that the acid oxide is stretched at the final stage, and as one proposal, a hot rolling process is used. In other words, the oxide stretched by hot rolling remains stretched without being crushed after cold rolling and annealing, and it is necessary to maintain an anisotropic shape until the final product. This difference is basically caused by the difference in the composition of the oxide if the hot rolling conditions are the same. In other words, enameled steel plates are preferably combined with a relatively soft Mn-containing oxide and hard Nb and B-containing oxides to promote crushing. On the other hand, in the steel according to the present invention, it is preferable that the oxide is uniform rather than a composite of oxides having different compositions, so that deformation during cold rolling is uniform and fracture is avoided.
[0017] ほうろう鋼板のように一時的に延伸したものであっても、その後の破砕により酸ィ匕物 の形状が等方的なものになってしまうと、本発明で特徴的な加工硬化能、結果として の良好な均一伸び、すなわち局部変形の抑制効果が全く発揮されない。  [0017] Even if the steel sheet is temporarily stretched like an enameled steel sheet, if the shape of the acid oxide becomes isotropic due to subsequent crushing, the work hardening ability characteristic of the present invention is achieved. As a result, the uniform elongation, that is, the effect of suppressing local deformation is not exhibited at all.
以上説明のように、ほうろう鋼板の製造技術を認識したとしても、酸化物を多量に含 有させる技術を本発明の対象鋼および用途に適用し、その形態の影響を検討しょう とすることは、たとえ同業者と言えども容易ではない。 As described above, even if the technology for producing enameled steel sheets is recognized, let us apply the technology that contains a large amount of oxide to the target steel and application of the present invention, and examine the effect of its form. It is not easy even if it is a peer.
本発明鋼は、酸化物を特定の形態に延伸したまま保持すれば、その加工硬化挙動 が劇的に変化し、局部変形を強く抑制することで、薄手鋼板であっても実用的な延性 に好ましく作用することを新規に知見し、発明されたものである。  If the steel of the present invention is held with the oxide stretched in a specific form, its work hardening behavior changes dramatically, and local deformation is strongly suppressed, so that even a thin steel plate has practical ductility. It was newly discovered and invented that it acts preferably.
発明の効果  The invention's effect
[0018] 本発明によれば、同じ強度、同じ全伸びであっても、高い均一伸びを有し、より高歪 域まで局部変形 (くびれ)の発生を抑えた硬質極薄手材を得ることができる。このため 、薄手材を使用する際に問題となる、均一変形性の不足による破断、くびれの発生を 抑止することが可能となる。  [0018] According to the present invention, it is possible to obtain a hard ultrathin material having high uniform elongation even with the same strength and the same total elongation, and suppressing the occurrence of local deformation (necking) to a higher strain range. it can. For this reason, it becomes possible to suppress the occurrence of breakage and constriction due to insufficient uniform deformability, which is a problem when using thin materials.
図面の簡単な説明  Brief Description of Drawings
[0019] [図 1]図 1は、本発明の硬質極薄鋼板の、鋼板板厚方向の部位を説明する図である。  [FIG. 1] FIG. 1 is a diagram for explaining a portion of a hard ultrathin steel plate according to the present invention in the thickness direction of the steel plate.
発明を実施するための最良の形態  BEST MODE FOR CARRYING OUT THE INVENTION
[0020] 以下、本発明を詳細に説明する。  [0020] Hereinafter, the present invention will be described in detail.
まず、成分について説明する。成分はすべて質量％である。 C量は、加工性の劣化 を回避するため、 C : 0. 800%以下とする。好ましくは 0. 100%以下、さらに好ましく は 0. 060%以下である。特に炭化物を本発明で特徴となる第二相として利用する場 合は、好ましくは 0. 0050〜0. 040%、さらに好ましくは 0. 0080〜0. 030%である 。様々な第二相の分散により材料を強化する本発明鋼では、強度確保などの観点で 必要となる C含有量は低くても構わない。 C : 0. 0050%以下でも必要な強度確保が 可能であり、 0. 0030%以下でも構わないし、 0. 0015%以下も可能である。 r値を向 上させて絞り成形性を高く保つ意味では、 C量は低 、方が好ま 、。  First, components will be described. All components are in weight percent. The C amount is set to C: 0.800% or less in order to avoid deterioration of workability. Preferably it is 0.100% or less, more preferably 0.060% or less. In particular, when carbide is used as the second phase, which is a feature of the present invention, the content is preferably 0.0050 to 0.040%, more preferably 0.0008 to 0.030%. In the steel of the present invention in which the material is strengthened by dispersing various second phases, the C content required from the viewpoint of securing the strength may be low. C: Necessary strength can be secured even at 0.0050% or less, 0.0003% or less may be sufficient, and 0.0015% or less is also possible. In order to keep the drawability high by increasing the r value, a lower C content is preferable.
[0021] N量も Cと同様、加工性の劣化を回避するため、 C : 0. 800%以下とする。好ましく は 0. 100%以下、さらに好ましくは 0. 060%以下である。特に、窒化物を本発明で 特徴となる第二相として利用する場合は、好ましくは 0. 0050〜0. 040%、さらに好 ましくは 0. 0080-0. 030%である。様々な第二相の分散により材料を強化する本 発明鋼では、強度確保などの観点で必要となる N含有量は低くても構わない。 N : 0. 0050%以下でも必要な強度確保が可能であり、 0. 0030%以下でも構わないし、 0 . 0015%以下も可能である。 r値を向上させ絞り成形性を高く保つ意味では、 N量は 低い方が好ましい。 [0021] Similarly to C, the N content is set to C: 0.800% or less in order to avoid deterioration of workability. Preferably it is 0.100% or less, more preferably 0.060% or less. In particular, when nitride is used as the second phase, which is a feature of the present invention, the content is preferably 0.0050 to 0.040%, more preferably 0.0008 to 0.030%. In the steel of the present invention that reinforces the material by dispersing various second phases, the N content required from the viewpoint of securing the strength may be low. N: Necessary strength can be ensured even if it is 0.0050% or less, 0.0030% or less may be sufficient, and 0.0015% or less is also possible. In order to improve the r value and maintain high drawability, the N amount is The lower one is preferable.
[0022] Siは多すぎると加工性、めっき性が劣化するため、 2. 0%以下とする。ただし、本発 明鋼において、第二相として酸ィ匕物を利用する場合は、後述のように、鋼中への酸 素の残存が難しくなることや、本発明にとって好ましい、延伸した酸化物を得にくくな る。また、第二相の形成に浸炭や窒化を利用する場合は、鋼中に侵入した Cや Nが 結晶粒界で粗大な Si炭化物や Si窒化物を形成し、脆性的な割れを起こすこともある 。以上のような弊害を回避するには、 Siを 1. 5%以下、さらに 1. 0%以下にする必要 力 S生ずることもある。特に成形性を高く保つ意味では、 Si量は低い方が好ましぐ 0. 5%以下、さらには 0. 1%以下、さらには 0. 07%以下とすることで成形性が向上する  [0022] If too much Si is included, workability and plating properties deteriorate, so the content is made 2.0% or less. However, in the present invention steel, when an oxide is used as the second phase, as described later, it is difficult for oxygen to remain in the steel, and a stretched oxide that is preferable for the present invention is used. It becomes difficult to obtain. In addition, when carburizing or nitriding is used to form the second phase, C and N entering the steel may form coarse Si carbide and Si nitride at the grain boundaries, causing brittle cracking. is there . In order to avoid the above adverse effects, Si may need to be 1.5% or less, and further 1.0% or less. In particular, in order to keep the moldability high, it is preferable that the Si content is low. 0.5% or less, further 0.1% or less, and further 0.07% or less improves the moldability.
[0023] Mnは多すぎるとカ卩ェ性、めっき性が劣化するため、 2. 0%以下とする。一方、本発 明鋼において、第二相として酸ィ匕物を利用する場合は、後述のように、本発明にとつ て好ましい、延伸した酸化物を得やすくする。また、第二相の形成に、硫化物を利用 する場合も、延伸した硫ィ匕物が得やすいため、有用な元素である。このため、 Mnの 好ましい範囲を、 0. 05〜： L 0%とする。さらに好ましくは 0. 15〜0. 8%、さらに好ま しくは 0. 25〜0. 7%である。 [0023] If the amount of Mn is too large, the caking property and the plating property deteriorate, so the content is made 2.0% or less. On the other hand, in the present invention steel, when an oxide is used as the second phase, it becomes easy to obtain a stretched oxide, which is preferable for the present invention, as will be described later. In addition, when a sulfide is used for forming the second phase, it is a useful element because it is easy to obtain a stretched sulfide. For this reason, the preferable range of Mn is 0.05-: L 0%. More preferably, it is 0.15 to 0.8%, and more preferably 0.25 to 0.7%.
Pは多すぎると加工性が劣化するば力りでなぐ第二相の形成に浸炭や窒化を利用 する場合は、鋼板の浸炭性、窒化性を阻害するため、 0. 10%以下とする。成形性を 高く保つ意味では P量は低い方が好ましぐ 0. 05%以下、さらには 0. 01%以下とす ることで成形性が向上する。  If P is too much, if carburizing or nitriding is used to form the second phase, which is difficult to process if the workability deteriorates, the content is set to 0.10% or less to inhibit the carburizing and nitriding properties of the steel sheet. In order to keep the moldability high, a lower P content is preferable. 0.05% or less, and even 0.01% or less improves moldability.
[0024] Sは熱間延性を劣化させ、铸造ゃ熱間圧延の阻害要因となるので、 0. 100%以下 とする。ただし、 Mn、 Cu、 Ti、 REMなどを多量に添加させ、これらの硫化物を、本発 明で必要とする第二相として利用する場合は、熱間延性の劣化も少なぐ有用な元 素でもある。このため、 Sの好ましい範囲を、 0. 015〜0. 080%とする。さらに好まし くは 0. 025〜0. 070%、さらに好ましくは 0. 035〜0. 060%である。  [0024] S degrades hot ductility and becomes a hindering factor for hot rolling, so it is made 0.10% or less. However, when a large amount of Mn, Cu, Ti, REM, etc. is added and these sulfides are used as the second phase required in the present invention, a useful element with little deterioration in hot ductility is used. But there is. Therefore, the preferable range of S is set to 0.015 to 0.080%. More preferably, it is 0.025 to 0.070%, and more preferably 0.035 to 0.060%.
[0025] A1は高いと铸造が困難となる、表面の疵が増加するなどの害があるため、 3. 0%以 下とする。ただし、 A1は強脱酸元素であるため、本発明鋼において、第二相として酸 化物を利用する場合は、鋼中への酸素の残存が難しくなるので、 0. 010%以下、さ らに 0. 005%以下、さらに 0. 002%以下、さらに 0. 001%以下にする必要が生ずる こともある。一方で、 Ni A1などの金属間化合物の形成元素となり、本発明で必要とす [0025] If A1 is high, forging is difficult and surface wrinkles increase. However, since A1 is a strong deoxidizing element, when using an oxide as the second phase in the steel of the present invention, it is difficult for oxygen to remain in the steel. In addition, it may be necessary to make the value 0.005% or less, 0.002% or less, and 0.001% or less. On the other hand, it becomes an element for forming intermetallic compounds such as Ni A1 and is required in the present invention.
3  Three
る第二相の分散にとって好ましい効果を有する。 A1とともに化合物を形成する金属元 素の種類や量にもよる力 この場合は、 1. 0%以上、さらには 1. 5%以上、さらには 2 . 0%以上とすることが好ましい。  This has a favorable effect on the dispersion of the second phase. Force depending on the type and amount of metal elements that form a compound with A1 In this case, it is preferably 1.0% or more, more preferably 1.5% or more, and even more preferably 2.0% or more.
[0026] Oは本発明で特徴的な第二相として酸ィ匕物を利用しな 、場合は、 Al、 Si、 Ti等によ り脱酸し、 0. 010%以下とすることが好ましい。これは、鋼中での酸化物が本発明の 効果にとって効果をもたな 、等方的 (球状)な形態となった場合、割れの起点となりや すいためである。有用な第二相として酸化物を利用する場合でも、酸化物が過剰に なると割れの起点となりやすいので、 0. 200%以下とする。好ましくは 0. 010-0. 1 00%、さらに好ましくは 0. 020〜0. 080%、さらに好ましくは 0. 030〜0. 050%で ある。 [0026] O does not use an oxide as the second phase characteristic of the present invention. In the case where O is not used, it is preferably deoxidized with Al, Si, Ti, or the like to 0.010% or less. . This is because if the oxide in the steel has no effect on the effect of the present invention and becomes isotropic (spherical), it is easy to start a crack. Even when an oxide is used as a useful second phase, an excess of the oxide tends to cause cracking, so the content is made 0.20% or less. Preferably it is 0.010-0.100%, More preferably, it is 0.020-0.080%, More preferably, it is 0.030-0.050%.
[0027] 次に、必要に応じて添加できる元素について説明する。  [0027] Next, elements that can be added as necessary will be described.
Tiは鋼板の再結晶温度を上げ、本発明が対象とする極薄鋼板の焼鈍通板性を著 しく劣化させる。このため 4. 00%以下とする。本発明で特徴となる第二相として Tiィ匕 合物を利用しない場合は、 Tiを添加する必要はなぐ 0. 04%以下、さらに好ましくは 0. 01%以下とする。一方で、 Tiの酸化物、硫化物、炭化物、窒化物、金属間化合物 は本発明で特徴となる第二相として利用でき、化合物を形成する元素の種類と量に もよるが、 0. 06%以上とするとその効果が十分に発揮される。さらに好ましくは 0. 10 0%以上である。  Ti raises the recrystallization temperature of the steel sheet, and significantly deteriorates the annealability of the ultrathin steel sheet which is the subject of the present invention. For this reason, it will be 4.00% or less. In the case where a Ti compound is not used as the second phase, which is a feature of the present invention, it is not necessary to add Ti, and the content is made 0.04% or less, more preferably 0.01% or less. On the other hand, Ti oxides, sulfides, carbides, nitrides, and intermetallic compounds can be used as the second phase characteristic of the present invention, and depending on the type and amount of elements forming the compound, 0.06 If it is more than%, the effect is fully exhibited. More preferably, it is 0.100% or more.
[0028] Nbも Tiと同様の影響を有し、再結晶温度を上げ、本発明が対象とする極薄鋼板の 焼鈍通板性を著しく劣化させる。このため、 4. 00%以下とする。本発明で特徴となる 第二相として Nb化合物を利用しない場合は、 Nbを添加する必要はなぐ 0. 04%以 下、さらに好ましくは 0. 01%以下とする。一方で、 Nbの酸化物、硫化物、炭化物、 窒化物、金属間化合物は、本発明で特徴となる第二相として利用でき、化合物を形 成する元素の種類と量にもよるが、 0. 06%以上にするとその効果が十分に発揮され る。さらに好ましくは 0. 100%以上である。  [0028] Nb has the same effect as Ti, raises the recrystallization temperature, and remarkably deteriorates the annealability of the ultrathin steel sheet targeted by the present invention. For this reason, it shall be 4.00% or less. When an Nb compound is not used as the second phase, which is a feature of the present invention, it is not necessary to add Nb, and the content is made 0.04% or less, more preferably 0.01% or less. On the other hand, oxides, sulfides, carbides, nitrides, and intermetallic compounds of Nb can be used as the second phase that is characteristic of the present invention, and depending on the type and amount of elements forming the compound, 0 The effect is fully demonstrated when it is over 06%. More preferably, it is 0.100% or more.
[0029] REMも Ti、 Nbと同様の効果を有する力 高価な元素であるので、 4. 00%以下と する。本発明で特徴となる第二相として REM化合物を利用しない場合は、 REMを 添加する必要はなぐ 0. 04%以下、さらに好ましくは 0. 01%以下とする。一方で、 R EMの酸化物、硫化物、炭化物、窒化物、金属間化合物は、本発明で特徴となる第 二相として利用でき、化合物を形成する元素の種類と量にもよるが、 0. 06%以上に すると、その効果が十分に発揮される。さらに好ましくは 0. 100%以上である。 [0029] REM is a powerful element that has the same effect as Ti and Nb. To do. When the REM compound is not used as the second phase, which is a feature of the present invention, it is not necessary to add REM, and the content is made 0.04% or less, more preferably 0.01% or less. On the other hand, REM oxides, sulfides, carbides, nitrides, and intermetallic compounds can be used as the second phase that is characteristic of the present invention, and depending on the type and amount of elements forming the compound, 0 If the value is 06% or more, the effect will be fully exerted. More preferably, it is 0.100% or more.
[0030] Bも Ti、 Nbと同様の効果を有する。ただし、添加量にもよる力 Tiや Nbと比較する と炭窒化物の形成能が小さぐ第二相として炭化物や窒化物を形成させる目的で、こ れらの元素と同時に添加した場合、鋼板の再結晶温度を上げ、本発明が対象とする 極薄鋼板の焼鈍通板性を著しく劣化させる。このため、 Ti, Nbの含有量が少ない場 合に有用となる。しかし過剰な添力卩は铸造時の铸片の割れが顕著になるため、上限 を 0. 0300%とする。本発明で特徴となる第二相として B化合物を利用しない場合は 、 Bを添加する必要はなぐ 0. 0020%以下、さらに好ましくは 0. 0010%以下とする 。一方で、 Bの酸化物、炭化物、窒化物、金属間化合物は本発明で特徴となる第二 相として利用でき、化合物を形成する元素の種類と量にもよる力 0. 0040%以上と するとその効果が十分に発揮される。さらに好ましくは 0. 0100%以上である。  [0030] B also has the same effect as Ti and Nb. However, the strength depending on the amount of addition When Ti and Nb are added at the same time as these elements for the purpose of forming carbides and nitrides as the second phase, the ability to form carbonitrides is small compared to Ti and Nb. The recrystallization temperature of the steel sheet is increased, and the annealing passability of the ultrathin steel sheet targeted by the present invention is significantly deteriorated. Therefore, it is useful when the content of Ti and Nb is low. However, since excessive cracking becomes prominent in cracks during fabrication, the upper limit is set to 0.0300%. When the B compound is not used as the second phase, which is a feature of the present invention, it is not necessary to add B, and it is 0.0010% or less, more preferably 0.0010% or less. On the other hand, the oxides, carbides, nitrides, and intermetallic compounds of B can be used as the second phase that is characteristic of the present invention, and the force depending on the type and amount of the elements forming the compound is 0.0040% or more. The effect is fully demonstrated. More preferably, it is 0.0100% or more.
[0031] Cuは多すぎると再結晶温度が顕著に上昇するば力りでなぐ表面性状を劣化させ 加工性、めっき性が劣化するため、 8. 00%以下とする。一方、本発明鋼において、 第二相として金属 Cu相や金属間化合物相なども利用できる。また、第二相の形成に 、硫化物を利用する場合も、延伸した硫ィ匕物が得やすいため有用な元素である。こ のため、好ましい範囲を、 0. 10〜4. 00%とする。さらに好ましくは 0. 20〜3. 00% 、さらに好ましくは 0. 30-2. 50%である。  [0031] If there is too much Cu, the recrystallization temperature will rise remarkably and the surface properties will be deteriorated by force, and workability and plating properties will deteriorate. On the other hand, in the steel of the present invention, a metallic Cu phase or an intermetallic compound phase can be used as the second phase. Also, when a sulfide is used for forming the second phase, it is a useful element because it is easy to obtain a stretched sulfide. For this reason, the preferable range is set to 0.10 to 4.00%. More preferably, it is 0.20 to 3.00%, and more preferably 0.30 to 2.50%.
Caは本発明鋼において、第二相として硫ィ匕物を利用する場合に、延伸した硫化物 が得やすいため有用な元素である。しかし反応性に富み、一般に鋼中に多量に含有 させることは困難なため、 1. 00%以下とする。好ましい範囲を、 0. 01〜0. 50%とす る。さら〖こ好ましくは 0. 05-0. 30%である。  In the steel of the present invention, Ca is a useful element because it is easy to obtain a stretched sulfide when a sulfide is used as the second phase. However, it is highly reactive and generally difficult to contain in steel in large quantities. A preferable range is 0.01 to 0.50%. More preferably, it is 0.05 to 30%.
[0032] Niは高価な元素であり、 8. 00%以下とする。本発明では、 Ni A1などの金属間化  [0032] Ni is an expensive element and should be 8.00% or less. In the present invention, intermetalization such as Ni A1
3  Three
合物の形成元素として、本発明で必要とする第二相の分散にとって好ましい効果を 有する。 Niと化合物を形成する金属元素の種類や量にもよるが、 1. 0%以上、さらに は 1. 5%以上、さらには 2. 0%以上とすることが好ましい。 As a compound forming element, it has a favorable effect on the dispersion of the second phase required in the present invention. 1.0% or more, depending on the type and amount of metal elements that form a compound with Ni Is preferably 1.5% or more, more preferably 2.0% or more.
Crも高価な元素であり、 20. 00%以下とする。本発明で特徴となる第二相として Cr 化合物を利用しない場合は、 Crを添加する必要はなぐ 0. 06%以下、さらに好まし くは 0. 02%以下とする。一方で、 Crの酸化物、硫化物、炭化物、窒化物、金属間化 合物は本発明で特徴となる第二相として利用でき、化合物を形成する元素の種類と 量にもよるが、 0. 10%以上とするとその効果が十分に発揮される。さらに好ましくは 0 . 50%以上、さらに好ましくは 1. 50%以上、さらに好ましくは 2. 50%以上である。  Cr is also an expensive element and should be 20.00% or less. When a Cr compound is not used as the second phase, which is a feature of the present invention, it is not necessary to add Cr, and it is 0.06% or less, more preferably 0.02% or less. On the other hand, Cr oxides, sulfides, carbides, nitrides, and intermetallic compounds can be used as the second phase that is characteristic of the present invention, and depending on the type and amount of elements forming the compound, 0 The effect is fully demonstrated when it is 10% or more. More preferably, it is 0.50% or more, more preferably 1.50% or more, and further preferably 2.50% or more.
[0033] 上記以外の元素についての含有量は特に限定しないが、本発明で規定していない 特性を付与するために、 Sn, Sb, Mo, Ta, V, Wを各元素について 0. 10%以下、 合計で 0. 50%以下含有することは、本発明の効果を何ら損ねるものではない。ただ し、これらの元素が粗大な等方的な形態を有する化合物を形成し、加工性を損ねる 場合があるため、注意が必要である。特に目的がない限り、各元素について 0. 010 %以下、合計で 0. 050%以下とすることが好ましい。さらに好ましくは各元素につい TO. 0020%以下、合計で 0. 0050%以下、さらに好ましくは各元素について 0. 00 10%以下、合計で 0. 0030%以下である。  [0033] The content of the elements other than the above is not particularly limited, but Sn, Sb, Mo, Ta, V, and W are added to each element in an amount of 0.1% to 10% in order to impart characteristics not specified in the present invention. Hereinafter, the total content of 0.50% or less does not impair the effects of the present invention. However, caution is required because these elements may form a coarse isotropic compound and impair the processability. Unless otherwise specified, the content of each element is preferably 0.010% or less and the total is preferably 0.050% or less. More preferably, it is TO. 0020% or less for each element, the total is 0.0050% or less, more preferably 0.0010% or less for each element, and the total is 0.0003% or less.
[0034] 次に、本発明で最も重要な、第二相について説明する。まず、第二相の観測等に 関して記述する。本発明で限定される第二相の観察方法は特に限定されるものでは な 、。形態は電子顕微鏡などのミクロ領域を観測可能な物理測定機器での直接観 測が可能である。比較的大きなものであれば、高倍率の光学顕微鏡でも観測は可能 である。光学顕微鏡や、走査型電子顕微鏡 (SEM)であれば、鋼板断面を研磨した もの、さらにそれをエッチングしたものを適用できるし、透過型電子顕微鏡 (TEM)で あれば、薄膜でもよいし SPEED法によって得られた抽出レプリカ等を観察することも 可能である。さら〖こ、電解抽出により母相を溶解した残渣を観察してもよい。また、観 察された第二相の同定は、 EDXや電子線回折パターンなどで行なうことが可能であ る力 これらの手法に限定されるものではなぐ現在性能向上が著しいどのような分析 機器を使用しても構わない。要は、第二相の形状、サイズおよび数密度、必要に応じ てその種類が、妥当と認められる方法により決定できればよい。種類によっては、様 々な相の複合的なものとなっており、完全な判別が困難な場合もあると考えられるが 、本発明の効果は、その種類によらず第二相を特定の形態で分散させれば得られる ものであるから、種類が決定できないものも本発明に含まれる。体積分率や数密度は 、より高度な分析機器を使用してより微細な窒化物まで考慮すれば、これらの値は増 加するが、通常レベルの物理機器を用いて、 0. 02 m以上の大きさのものを対象と すれば本発明の効果を判別することが可能である。 Next, the most important second phase in the present invention will be described. First, the second phase observation will be described. The second phase observation method limited in the present invention is not particularly limited. The form can be directly observed with a physical measuring instrument capable of observing the micro area such as an electron microscope. Observation with a high-magnification optical microscope is possible if it is relatively large. For an optical microscope or a scanning electron microscope (SEM), a polished steel plate cross section or an etched one can be applied. For a transmission electron microscope (TEM), a thin film or a SPEED method can be used. It is also possible to observe the extracted replica obtained by the above. Furthermore, a residue obtained by dissolving the parent phase by electrolytic extraction may be observed. In addition, the identification of the observed second phase is a force that can be performed by EDX or electron diffraction patterns, etc. You can use it. The point is that the shape, size and number density of the second phase, and if necessary, the type can be determined by a method that is recognized as appropriate. Depending on the type, it is a composite of various phases, and it may be difficult to distinguish completely. The effect of the present invention can be obtained by dispersing the second phase in a specific form regardless of the type, and therefore, the type of which cannot be determined is also included in the present invention. Volume fractions and number densities will increase if finer nitrides are taken into account using more sophisticated analytical instruments, but more than 0.02 m using normal level physical instruments The effect of the present invention can be discriminated if the target is of a size of.
[0035] このように観察される第二相につ 、て、平均長径が 0. 10 m以上、平均短径が 0 . 05 m以上で平均長径 Z平均短径≥ 2. 0である第二相を体積分率で、 0. 05% 以上含有することが本発明の特徴である。サイズは、平均長径について好ましくは、 0. 20 m以上、さら〖こ好ましくは 0. 50 m以上、さら〖こ好ましくは 1. 00 m以上、 さらに好ましくは 2. 00 /z m以上、さらに好ましくは 5. 00 /z m以上である。ただし、あ まりに大きな第二相を存在させると、加工初期にお 、て破断の起点となってしま 、、 延性を顕著に劣化させる場合があるので、 30 m以下とすることが好ましい。さらに 好ましくは 20 m以下である。ただし、粗大なものでも個数が非常に少ない場合は、 悪影響の程度は小さいので、これを超える粗大なものが存在すれば直ちに本発明を 外れるというものでもない。平均長径 Z平均短径は、好ましくは 3. 0以上、さらに好ま しくは 5. 0以上、さらに好ましくは 8. 0以上である。また、体積分率は、好ましくは 0. 1%以上、さらに好ましくは 0. 3%以上、さらに好ましくは 1. 0%以上、さらに好ましく は 2. 0%以上である。ただし、あまりに第二相の量が多いと、加工初期において破断 の起点となってしまい、延性を顕著に劣化させる場合があるので、 20%以下とするこ とが好ましい。さらに好ましくは 10 %以下である。 [0035] In the second phase thus observed, the average major axis is 0.10 m or more, the average minor axis is 0.05 m or more, the average major axis Z the average minor axis ≥ 2.0. It is a feature of the present invention that the phase is contained in a volume fraction of 0.05% or more. The size is preferably about 0.20 m or more with respect to the average major axis, more preferably 0.50 m or more, more preferably 1.00 m or more, more preferably 2.00 / zm or more, more preferably 5. 00 / zm or more. However, if an excessively large second phase is present, it becomes the starting point of fracture at the initial stage of processing, and the ductility may be significantly deteriorated. Therefore, it is preferably 30 m or less. More preferably, it is 20 m or less. However, even if the number is coarse, if the number is very small, the degree of the adverse effect is small. Therefore, if there is a coarse one exceeding this, the present invention is not immediately deviated from the present invention. Average major axis The average minor axis Z is preferably 3.0 or more, more preferably 5.0 or more, and still more preferably 8.0 or more. Further, the volume fraction is preferably 0.1% or more, more preferably 0.3% or more, further preferably 1.0% or more, and further preferably 2.0% or more. However, if the amount of the second phase is too large, it becomes a starting point of fracture at the initial stage of processing, and the ductility may be remarkably deteriorated. More preferably, it is 10% or less.
[0036] この第二相の数密度については、鋼板断面で観察した場合、 0. 01個/ / z m2以上 、抽出レプリカや透過型電子顕微鏡での薄膜観察等、空間的な分散を測定した場合 は、 0. 001個 Z m2以上とすることで、本発明の効果が顕著になる。断面観察の場 合、好ましくは 0. 03個 Z m2以上、さらに好ましくは 0. 1個 Zw m2以上、さらに好 ましくは 0. 3個 Z m2以上である。また、空間的な測定の場合、好ましくは 0. 003個 Zw m3以上、さらに好ましくは 0. 01個 Z m3以上、さらに好ましくは 0. 03個 m3以上である。これらの数密度は、上記のサイズや体積分率との関連しており、サイ ズゃ体積分率と同様に加工性を劣化させない範囲で、極端に大きくしたり小さくした りしな 、ように注意する必要がある。 [0036] Regarding the number density of this second phase, when observed on the cross section of the steel sheet, 0.01 dispersion / zm 2 or more, spatial dispersion was measured, such as thin film observation with an extraction replica or a transmission electron microscope. In this case, the effect of the present invention becomes remarkable by setting it to 0.001 Zm 2 or more. Cross-sectional observation of the case, preferably 0.03 or Z m 2 or more, more preferably 0.1 or Zw m 2 or more, still good Mashiku is 0.3 or Z m 2 or more. In the case of spatial measurement, it is preferably 0.003 pieces Zw m 3 or more, more preferably 0.01 pieces Z m 3 or more, further preferably 0.03 pieces m 3 or more. These number densities are related to the above-mentioned size and volume fraction, and as with the size volume fraction, they are extremely increased or decreased within a range that does not degrade workability. It is necessary to be careful.
[0037] このように第二相の形態を制御することにより局部変形の発生が抑制されるメカニズ ムは明確ではないが、以下に説明を試みる。  [0037] The mechanism by which the occurrence of local deformation is suppressed by controlling the form of the second phase in this way is not clear, but will be explained below.
本発明における第二相は、母相である Fe相よりも硬質なものであるため、鋼板が変 形する場合、母相の変形が優先して起きる。さらに、第二相により母相の変形が拘束 されるため、母相の加工硬化は著しくなる。このため、歪の伝播性がよくなり、より広い 領域で変形を受け持ちながら変形が継続し、均一伸びが高くなるものと思われる。異 方性を有する第二相を分散させた場合、母相拘束の程度が一般的な等方的第二相 に比較して大きくなつていると考えられる。またはこれとは別に、異方性の強い第二相 は母相との結合状態が弱くなつており、変形に伴いその界面がすべり変形し、さらに は多くのボイドを生成することで変形を担っているとも考えられる。このため、より高い 歪領域まで母材そのものの変形が抑制されたような状態になっており、均一変形が 継続するものとも考えられる。本発明鋼は、大きな加工硬化量を持つと同時に、局部 変形能は低下することが多いが、これらを含め、現象を完全に説明できるメカニズム は明確になっていない。  Since the second phase in the present invention is harder than the Fe phase, which is the parent phase, when the steel sheet is deformed, the deformation of the parent phase occurs preferentially. Furthermore, since the deformation of the parent phase is constrained by the second phase, the work hardening of the parent phase becomes significant. For this reason, it is considered that the strain propagation is improved, the deformation continues while taking on the deformation in a wider area, and the uniform elongation becomes higher. When the anisotropic second phase is dispersed, the parent phase constraint is considered to be greater than the general isotropic second phase. Or, apart from this, the second phase with strong anisotropy is weakly bonded to the parent phase, and its interface slips along with the deformation, and further deforms by generating many voids. It is thought that it is. For this reason, the deformation of the base metal itself is suppressed to a higher strain region, and it is considered that the uniform deformation continues. The steel of the present invention has a large work hardening amount and at the same time the local deformability is often lowered, but the mechanism that can fully explain the phenomenon is not clear.
[0038] 本発明鋼での均一変形が第二相ではなぐ母相すなわち体積的に一番多い主相 の変形によって担われていることは間違いない。この主相が Feであるのは当然である 力 本発明では、この主相は Feのフェライト相と想定し、その体積率は 80%以上とす ることが好ましい。一般に Feを主体とする相としては、パーライトやべイナイト、マルテ ンサイト相などが知られているが、本発明では、高強度化は第二相の分散によって達 成して 、るので、主相は軟質かつ均一な相が加工性の観点力 好まし 、ためである 。また、体積率は過剰な第二相の生成による延性劣化を回避するため、好ましくは 8 5%以上、さらに好ましくは 90%以上とする。  [0038] There is no doubt that uniform deformation in the steel of the present invention is borne by the deformation of the main phase that is the largest in volume, that is, the main phase that is not in the second phase. It is natural that this main phase is Fe. In the present invention, this main phase is assumed to be a ferrite phase of Fe, and its volume fraction is preferably 80% or more. In general, pearlite, bainite, martensite phase, etc. are known as the phase mainly composed of Fe. However, in the present invention, the increase in strength is achieved by the dispersion of the second phase. This is because a soft and uniform phase is preferred from the viewpoint of workability. Further, the volume ratio is preferably 85% or more, more preferably 90% or more in order to avoid ductile deterioration due to the generation of an excessive second phase.
さらに第二相と主相の方位関係も重要な要件となる。上述のメカニズムでも触れた 力 本発明の効果は、 Fe相と第二相の結合状態によっていると考えられることと関係 し、第二相の平均長径の方向はその第二相が接している Fe相のく 100>方位また はく 110 >方位であることが好ましい。この方位関係については、通常の電子線回 折等で検知可能なものである。 [0039] 次に第二相そのものの種類について記述する。本発明では第二相が酸ィ匕物、硫ィ匕 物、炭化物、窒化物、金属間化合物の単体または複合ィ匕合物である場合に、顕著な 効果を得ることができる。酸化物の場合は Fe、 Mn、 Si、 Al、 Cr、 REM, Ti、 Nbの一 種または二種を含有する酸ィ匕物であること、硫ィ匕物である場合は Ti、 Mn、 Cu、 Ca、 REMの一種または二種を含有する硫ィ匕物であること、炭化物の場合は Fe、 Ti、 Nb 、 Si、 Crの一種または二種を含有する炭化物であること、窒化物である場合は Fe、 T i、 Nb、 Al、 B、 Crの一種または二種を含有する窒化物であること、金属間化合物で ある場合は Fe、 Ti、 Nb、 Al、 Si、 Mnの一種または二種を含有する金属間化合物で ある。炭化物に関しては、一般的な鋼で観察されるパーライト組織、すなわち高温で のオーステナイト相からの変態に伴い生成するフェライト相とセメンタイトの層状組織 は、本発明の効果が全く得られないため除外する。また、変態金属間化合物としては 、 NiAl、 Ni Al、 Ni (Al, Ti)、 Ni TiAl、 Ni Ti、 Ni Mo、 Ni Mo、 Ni Nb、 Co W、 F Furthermore, the orientation relationship between the second phase and the main phase is also an important requirement. The force mentioned in the above mechanism The effect of the present invention is related to the fact that it is considered to be due to the combined state of the Fe phase and the second phase, and the direction of the average major axis of the second phase is the Fe in contact with the second phase. It is preferred that the phase is 100> orientation or 110> orientation. This orientation relationship can be detected by ordinary electron beam diffraction. [0039] Next, the type of the second phase itself will be described. In the present invention, a remarkable effect can be obtained when the second phase is a simple substance or a composite compound of an oxide, a sulfide, a carbide, a nitride, or an intermetallic compound. In the case of oxide, it must be an oxide containing one or two of Fe, Mn, Si, Al, Cr, REM, Ti, Nb, and in the case of oxide, Ti, Mn, Cu It is a sulfide containing one or two of Ca, REM, and in the case of carbide, it is a carbide containing one or two of Fe, Ti, Nb, Si, Cr, and nitride. In the case of a nitride containing one or two of Fe, Ti, Nb, Al, B, Cr, and in the case of an intermetallic compound, one or two of Fe, Ti, Nb, Al, Si, Mn It is an intermetallic compound containing seeds. With regard to carbides, the pearlite structure observed in general steels, that is, the layered structure of ferrite phase and cementite formed by transformation from the austenite phase at high temperature is excluded because the effect of the present invention cannot be obtained at all. In addition, the transformation intermetallic compounds include NiAl, Ni Al, Ni (Al, Ti), Ni TiAl, Ni Ti, Ni Mo, Ni Mo, Ni Nb, Co W, F
3 3 2 3 3 4 3 3 e Mo、 Fe Ti、 Fe (Ni、 Co)などがある。上述の酸化物、硫化物、炭化物、窒化物、 3 3 2 3 3 4 3 3 e Mo, Fe Ti, Fe (Ni, Co), etc. The above-mentioned oxides, sulfides, carbides, nitrides,
2 2 2 2 2 2
金属間化合物は、一般的に鉄鋼材料中で観察される化合物であり、特殊なものであ る必要はないが、特殊な化合物を発明範囲内の形態で形成させることも可能である。 その種類は上記のものに限ったものではなぐあくまでも代表的な元素を挙げたにす ぎない。また、鋼中に存在する第二相は一種に限ったものではなぐ二種以上が存 在している場合も本発明に含まれる。これらは独立に存在していてもよぐ複合化合 物を形成していても構わない。さらには、形態的に本発明に包含されない相が同時 に存在して ヽても構わな 、。  Intermetallic compounds are compounds that are generally observed in steel materials and need not be special, but it is also possible to form special compounds in a form within the scope of the invention. The types are not limited to the above, but only representative elements are listed. Further, the present invention includes a case where two or more types of second phases existing in steel are not limited to one type. These may be present independently or may form a composite compound. Furthermore, a phase that is not included in the present invention may be present at the same time.
[0040] 要は、第二相の形態的な特徴が重要である。とは言え、形成させた第二相によりそ の効果の大きさには少な力もざる差があるのは事実である。この差は、鋼板中に生成 させうる第二相の種類と量によるものや、後述のような製造条件によって制御できる 形態の差、さらには、母相との結合状態とも関連した第二相そのものの種類の影響も 考えられる。  [0040] In short, the morphological characteristics of the second phase are important. However, it is true that there is a slight difference in the magnitude of the effect depending on the second phase formed. This difference depends on the type and amount of the second phase that can be generated in the steel sheet, the difference in form that can be controlled by the manufacturing conditions described later, and the second phase itself that is also related to the bonding state with the parent phase. The kind of influence is also conceivable.
[0041] これらの影響は完全には分離しきれてはいないが、現象的には、以下のように好ま しい第二相の種類および第二相を形成する元素を分類できる。種類としては、金属 間化合物 >炭化物 ^窒化物 >酸ィ匕物 >硫ィ匕物である。ただし、これは形態と量が同 一と仮定した時の効果を推定したものであり、製造法や第二相の種類によっては、量 の確保や形態の制御が困難となることもあるため、この順位は一応の目安にすぎな い。各元素の効果としては、以下のようなことが言える。酸化物の場合は Fe、 Mn、 R EMを含んだものが好ましぐ Si、 Al、 Cr、 Ti、 Nbは効果が小さい。硫化物である場 合は Mn、 Ca、 REMが好ましぐ Ti、 Cuの効果は小さい。炭化物の場合は Cr、 Ti、 S iが好ましぐ Fe、 Nbの効果は小さい。窒化物である場合は Fe、 Ti、 B、 Crが好ましく 、 Nb、 A1の効果は小さい。金属間化合物である場合は Fe、 Al、 Si、 Mnが好ましぐ Ti、 Nbは効果が小さい。 [0041] Although these effects are not completely separated, in terms of phenomena, the types of preferred second phases and the elements forming the second phase can be classified as follows. The types are: intermetallic compounds> carbides ^ nitrides>oxides> sulfates. However, this is the same form and quantity This order is only an estimate, because it may be difficult to secure the quantity and control the form depending on the type of production method and the second phase. Yes. The following can be said as the effect of each element. In the case of oxides, those containing Fe, Mn, and REM are preferred. Si, Al, Cr, Ti, and Nb are less effective. In the case of sulfides, Mn, Ca, and REM are preferred. Ti and Cu are less effective. In the case of carbides, Cr, Ti, and Si are preferred. Fe and Nb are less effective. In the case of a nitride, Fe, Ti, B, and Cr are preferable, and the effect of Nb and A1 is small. In the case of intermetallic compounds, Fe, Al, Si, and Mn are preferred. Ti and Nb are less effective.
[0042] ここで、本明細書中で用いる鋼板板厚方向の部位について、図 1を用いて記述す る。「板厚表層 1Z8」、「板厚中心層 1Z4」とは、図 1中の対応領域を表す。なお、「 板厚表層 1Z8」に対応する領域は、鋼板の両表面について存在するが、本発明で はそのどちらか一面についてでも本発明の限定範囲に該当するものを対象とする。 製造法を工夫し、表と裏の窒化物分布を変化させることは比較的容易であるが、本 発明ではそのような表裏異表層の鋼板についても対象とする。これは片面のみでも 本発明が目的とする均一変形性の向上効果を得ることが可能だ力もである。また、上 記の体積率や数密度は、測定値が異常値ではな 、と言える程度のデータを採取し、 表層 1Z8内、中心層 1Z4内それぞれの特定箇所で本発明の条件を満たしていれ ば十分である。なお、「板厚 1/8位置」も「板厚表層 1/8」に含まれる。  [0042] Here, the part in the thickness direction of the steel sheet used in this specification will be described with reference to FIG. “Thickness surface layer 1Z8” and “thickness center layer 1Z4” represent the corresponding regions in FIG. The region corresponding to “plate thickness surface layer 1Z8” exists on both surfaces of the steel plate, but in the present invention, either one of the surfaces falls within the scope of the present invention. Although it is relatively easy to devise the manufacturing method and change the nitride distribution on the front and back sides, the present invention also covers such steel sheets with different front and back layers. This is also a force that can obtain the effect of improving the uniform deformability aimed by the present invention on only one side. For the above volume ratio and number density, data that can be said to be such that the measured value is not an abnormal value is collected, and the conditions of the present invention are satisfied at each specific location in the surface layer 1Z8 and the central layer 1Z4. It is enough. “Plate thickness 1/8 position” is also included in “Plate thickness surface 1/8”.
[0043] 本発明で特徴的な第二相は、鋼板の板厚方向での分布を考えた場合、全体に均 一に分散している必要はなぐ板厚方向に偏在していても構わない。むしろ、板厚方 向に層状に、第二相が多い層と少ない層とを交互に複層構造を形成させることがで きれば、その方が、本発明の効果にとっては都合がよい。このメカニズムは明確では ないが、第二相が多い層と少ない層とが、お互いに他方の変形を拘束し合うことで、 加工硬化量が増大し、局部変形が抑制されるためと考えられる。これは、上述の、第 二相と母相の間での拘束関係に似たような効果力 マクロな空間で生じているものと も考えられる。特に、第二相を鋼板表層部に集中的に分布させることで、本発明の効 果の大きな部分を得ることが可能である。すなわち、第二相の体積率について、（板 厚表層 1Z8での体積率) Z (板厚中心層 1Z4での体積率）≥10、または第二相の 数密度について、（板厚表層 1Z8での数密度) Z (板厚中心層 1Z4での数密度）≥ 10とすることが好ましい。これらの比は、好ましくは 20以上、さらに好ましくは 50以上 、さらに好ましくは 100以上、さらに好ましくは 200以上である。ただし、あまりに多くの 第二相を表層部に形成すると、表面欠陥ともなり、破断しやすくなる場合もあるので、 注意を要する。 [0043] The second phase characteristic of the present invention may be unevenly distributed in the plate thickness direction, which need not be uniformly distributed as a whole when considering the distribution in the plate thickness direction of the steel plate. . Rather, it is more convenient for the effect of the present invention if a multi-layer structure can be formed alternately in layers in the thickness direction, with layers having a large number of second phases and layers having a small number of second phases. Although this mechanism is not clear, it is thought that the amount of work hardening increases and the local deformation is suppressed when the layer with a large amount of the second phase and the layer with a small amount of each other restrain the deformation of the other. This is thought to be caused by a macroscopic space that is similar to the restraint relationship between the second phase and the parent phase described above. In particular, it is possible to obtain a large portion of the effect of the present invention by intensively distributing the second phase in the surface layer portion of the steel sheet. That is, for the volume fraction of the second phase, (volume fraction at the plate thickness surface layer 1Z8) Z (volume fraction at the plate thickness center layer 1Z4) ≥10, or The number density is preferably (number density in the plate thickness surface layer 1Z8) Z (number density in the plate thickness center layer 1Z4) ≥10. These ratios are preferably 20 or more, more preferably 50 or more, further preferably 100 or more, and more preferably 200 or more. However, if too much second phase is formed on the surface layer, it becomes a surface defect and may break easily.
[0044] 次に本発明が対象とする鋼板の特性等について記す。まず、本発明は板厚が 0. 4 OOmm以下の鋼板に適用されることと限定する。これより板厚が厚い鋼板では力卩ェに おいては、くびれが発生した後もある程度まで局部延性により成形が進行するため、 本発明技術のように均一伸びのみに限定した技術は意味をなさなくなるからである。 本技術は、より好ましくは 0. 250mm以下、さらに好ましくは 0. 200mm以下、さらに 好ましくは 0. 150mm以下の極薄鋼板でその有用性が発揮される。  [0044] Next, characteristics of the steel sheet to which the present invention is applied will be described. First, the present invention is limited to being applied to a steel plate having a thickness of 0.4 OO mm or less. In the case of a steel plate having a thicker thickness than this, in the force zone, forming progresses to a certain extent even after the occurrence of constriction. Therefore, a technique limited to only uniform elongation as in the technique of the present invention does not make sense. Because it disappears. The present technology demonstrates its usefulness with an ultra-thin steel sheet having a thickness of preferably 0.250 mm or less, more preferably 0.200 mm or less, and even more preferably 0.150 mm or less.
[0045] また、薄手材であっても、軟質材においてはそれなりの均一伸びを付与することが 可能であることから、本技術の適用範囲は硬質材とする。これは本発明の特徴である 第二相によって少な力 ず硬質ィ匕してしまう結果でもある。好ましい適用材 ίお IS5号 試験片による弓 I張試験（すなわち、幅 25mmで長さ 60mmの平行部を有する弓 |張試 験片を用いて、評点間距離を 50mm、変形速度を 5mmZ分とする引張試験）にお ける最高強度≥350MPa、かつ、ロックウェル硬度 HR30T≥ 54である鋼板である。 さらに好ましくは最高強度≥400MPa、かつ、ロックウェル硬度 HR30T≥ 57、さらに 好ましくは最高強度≥450MPa、かつ、ロックウェル硬度 HR30T≥ 61である。また、 本発明鋼は前言 6JIS5号試験片による引張試験において、均一伸び Z局部伸び≥1 . 0となることが特徴である。この比は好ましくは 1. 5以上、さらに好ましくは 2. 0以上 、さらに好ましくは 3. 5以上、さらに好ましくは 5. 0以上である。また、前述のように本 発明鋼は加工硬化量が大きいことも特徴である。前言 6JIS5号試験片による引張試験 において、降伏応力 Z最高強度≤0. 9、さらに好ましくは 0. 8以下、さらに好ましく は 0. 7以下、さらに好ましくは 0. 6以下である。  [0045] Further, even if it is a thin material, it is possible to impart an appropriate uniform elongation to a soft material, and therefore the scope of application of the present technology is a hard material. This is also the result that the second phase, which is a feature of the present invention, is hardened with little force. Preferred material ίO IS5 bow with test piece I tension test (ie, a bow with a parallel part of 25mm in width and 60mm in length | Using a test piece, the distance between grades is 50mm and the deformation speed is 5mmZ min. Steel with a maximum strength of ≥350 MPa and Rockwell hardness of HR30T≥54. More preferably, the maximum strength is ≥400 MPa and the Rockwell hardness is HR30T≥57, more preferably the maximum strength is ≥450 MPa and the Rockwell hardness is HR30T≥61. In addition, the steel of the present invention is characterized by uniform elongation Z local elongation ≥1.0 in the tensile test using the JIS No. 5 test piece. This ratio is preferably 1.5 or more, more preferably 2.0 or more, further preferably 3.5 or more, and further preferably 5.0 or more. Further, as described above, the steel of the present invention is also characterized by a large amount of work hardening. Preliminary Statement 6 In a tensile test using JIS No. 5 specimens, the yield stress Z maximum strength ≤ 0.9, more preferably 0.8 or less, more preferably 0.7 or less, and even more preferably 0.6 or less.
[0046] 以下に、本発明鋼の第二相の種類別に好ましい製造法の一例を示す。  [0046] An example of a preferable production method for each type of the second phase of the steel of the present invention is shown below.
まず、特徴的な第二相として酸化物を利用する場合を示す。  First, a case where an oxide is used as a characteristic second phase is shown.
好ましい形態の一つは酸ィ匕物を熱延工程で、圧延により延伸し好ましい形態へと 変化させるものである。このためには、ある程度の加工量が必要であり、铸造を完了 した鋼片の厚さを 50mm以上としておくことが好ましい。さらに好ましくは 150mm以 上である。また、酸化物が延伸後に適当なサイズを有するようにするため、延伸される 前の酸化物のサイズは、 10 m〜25 mとすることが好ましい。あまりに微細なもの は延伸しにくぐ粗大なものは圧延後の空間的な分散状態が直線的となり、本発明の 効果にとって好ましくない。そして熱間での圧延カ卩ェにおいて 1000°C以上かつ歪速 度 1Z秒以上の条件で真歪の総和で 0. 4以上の圧延を行なった後、 1000°C以下か つ歪速度 10Z秒以上の条件で真歪の総和で 0. 7以上の圧延を行なうことが効果的 である。このメカニズムは明確ではないが、以下のように考えられる。 1000°C以上の 高温域では、酸化物も軟化しており、加工硬化した地鉄との硬度差が小さくなるため 圧延により酸化物は延伸し、本発明にとって好ましい針状の酸ィ匕物を得ることができ る。そして 1000°Cより低温、約 900°C以下になると酸ィ匕物は延伸しに《なり、部分 的に破砕し、適度に針状の形態をもつ酸ィ匕物が鋼板中に適当な間隔をおいて分散 することになる。このように適度に延伸かつ分散させるには、熱延時の温度制御およ び各温度域での歪量、さらに加工硬化した地鉄の軟化を制御するため歪速度の制 御も重要となる。 One of the preferred forms is a hot rolling process in which the acid oxide is stretched by rolling into a preferred form. It is something to change. For this purpose, a certain amount of processing is required, and it is preferable that the thickness of the steel slab after completion of forging be 50 mm or more. More preferably, it is 150 mm or more. In order to make the oxide have an appropriate size after stretching, the size of the oxide before being stretched is preferably 10 m to 25 m. Too fine ones that are difficult to stretch are not preferable for the effects of the present invention because the spatial dispersion after rolling becomes linear. Then, after rolling with a total roll of 0.4 or more under the condition of 1000 ° C or more and strain rate of 1Z seconds or more in hot rolling, 1000 ° C or less and strain rate of 10Z seconds It is effective to perform rolling with a total true strain of 0.7 or more under the above conditions. Although this mechanism is not clear, it can be considered as follows. In a high temperature range of 1000 ° C or higher, the oxide is also softened, and the difference in hardness from the work-hardened steel is reduced, so that the oxide is stretched by rolling, and a needle-shaped oxide is preferable for the present invention. Obtainable. When the temperature is lower than 1000 ° C and lower than about 900 ° C, the acidic product becomes stretched, partially crushed, and the moderately acicular shaped acidic product is placed in the steel plate at an appropriate interval. Will be dispersed. In order to appropriately stretch and disperse in this way, it is also important to control the strain rate in order to control the temperature control during hot rolling, the amount of strain in each temperature range, and the softening of the work-hardened steel.
この温度、歪量および歪速度条件を硫化物にも適用することで、酸化物と同様の好 ま 、効果を得ることが可能である。  By applying these temperature, strain amount and strain rate conditions to sulfides, it is possible to obtain the same effects and effects as oxides.
次に、特徴的な第二相として炭化物を利用する場合を示す。  Next, the case where a carbide | carbonized_material is utilized as a characteristic 2nd phase is shown.
この場合は、あら力じめ鋼中に含有させた Cと添加元素から、製造工程の熱処理等 により好ましい形態を有する炭化物を生成させることが可能であるが、本明細書では より好ましい形態として浸炭を活用した方法について示す。浸炭によれば、前述のよ うに、鋼板の表面のみに特徴的な第二相を分散させることが可能で、 C濃度が徐々 に高まっていくため、優先的な方位に成長した異方的な形態を持つ炭化物を形成さ せやすい。その条件としては、冷延後、再結晶焼鈍と同時、またはその後に、 600°C 〜700°Cの温度域で、 { (浸炭時間 (秒) ) * (浸炭温度 (°C) ) }/{ (浸炭性ガス濃度（ %) ) * (浸炭処理での冷却速度 (°CZ秒)） }≥20なる条件で浸炭処理を行い、 C量 を 0. 0002%以上増力！]させる。温度がこの範囲を外れると、低温側では浸炭効率が 低下し、逆に高すぎると炭化物の形態が等方的なものになりやすくなる。 { (浸炭時間In this case, it is possible to generate carbides having a preferred form by heat treatment in the production process, etc., from C and additive elements contained in the tempered steel. We will show you how to use. By carburizing, as described above, it is possible to disperse the characteristic second phase only on the surface of the steel plate, and the C concentration gradually increases. It is easy to form carbide with form. The conditions are: (cold time (seconds)) * (carburizing temperature (° C))} / in the temperature range of 600 ° C to 700 ° C after cold rolling and simultaneously with recrystallization annealing. {(Carburizing gas concentration (%)) * (Cooling rate in carburizing treatment (° CZ seconds))} Carburizing is performed under the condition of ≥20, and the C content is increased by more than 0.0002%! ] If the temperature is outside this range, the carburizing efficiency is reduced on the low temperature side. On the contrary, if it is too high, the form of the carbide tends to be isotropic. {(Carburizing time
(秒)） * (浸炭温度 (°C)) }Z{ (浸炭性ガス濃度 (％；) ) * (浸炭処理での冷却速度（ °CZ秒) Mが 20以上の場合には、第二相の好ましい形態が達成される。基本的には 、低 C濃度で炭化物の析出核の生成を抑制しながら、高温、長時間および緩冷却の 処理で炭化物を十分に成長させることで、異方性を有する第二相の発達が顕著にな る。ただし、高温かつ長時間の浸炭を行うと、板の表面から鋼中に侵入した Cが拡散 により板厚の中心まで到達し、前述の複層構造による発明効果の増進効果が消失し てしまう。このため、浸炭処理条件に応じて、表層部のみが浸炭されるように上の式 の値を制御することが好ましい。この値は板厚等にもよる力 500以下、さらには 200 以下とすることが好ましい。浸炭性ガスの種類を含めた雰囲気の条件は一般的に知 られている条件を用いればよい。また、浸炭方法はここに示したガス浸炭に限定され るものではなぐ一般的に知られている浸炭方法を適用することが可能である。また、 Cの増加量、 0. 0002%以上は増加量としては非常に小さく見える力 極薄材にお ける鋼板表層での増加量を考えると発明の効果の発現には十分な量である。 (Sec)) * (Carburizing temperature (° C))} Z {(Carburizing gas concentration (%;))) * (Cooling rate in carburizing treatment (° CZ sec) When M is 20 or more, the second The preferred form of the phase is achieved, basically by anisotropically growing the carbides sufficiently at high temperature, for a long time and under slow cooling while suppressing the formation of carbide precipitation nuclei at low C concentrations. However, when carburizing at high temperature for a long time, C that has entered the steel from the surface of the plate reaches the center of the plate thickness due to diffusion, and the above-mentioned double phase is developed. Therefore, it is preferable to control the value of the above equation so that only the surface layer is carburized according to the carburizing conditions. It is preferable that the force is 500 or less, more preferably 200 or less, etc. The conditions of the atmosphere including the type of carburizing gas are generally known. In addition, the carburizing method is not limited to the gas carburizing shown here, and it is possible to apply a generally known carburizing method. An amount of 0.00002% or more is a force that seems to be very small as the amount of increase. Considering the amount of increase in the surface layer of the steel sheet in an ultrathin material, it is a sufficient amount for manifesting the effect of the invention.
[0048] また、この浸炭条件は、第二相として窒化による窒化物を適用する場合の条件とす ることで、炭化物と同様の好ましい効果を得ることが可能である。すなわち、冷延後、 再結晶焼鈍と同時、またはその後に、 600〜700°Cの温度域で、 { (窒化時間（秒)） * (窒化温度 (°C)) }Z{ (窒化性ガス濃度（％) ) * (窒化処理での冷却速度 (°CZ秒 ) ) }≥20なる条件で窒化処理を行い、 N量を 0. 0002%以上増加させる。窒化性ガ スの種類を含めた雰囲気の条件は、一般的に知られている条件を用いればよい。ま た、窒化方法は、ここに示したガス窒化に限定されるものではなぐ一般的に知られ ている窒化方法を適用することが可能であることは浸炭の場合と同様である。  [0048] Further, when the carburizing conditions are the conditions in the case of applying nitride by nitriding as the second phase, it is possible to obtain a preferable effect similar to that of carbide. That is, after cold rolling, simultaneously with recrystallization annealing, or after that, in the temperature range of 600 to 700 ° C, {(nitriding time (seconds)) * (nitriding temperature (° C))} Z {(nitriding gas Concentration (%)) * (Cooling rate in nitriding treatment (° CZ sec))} nitriding is performed under the condition of ≥20, and the N content is increased by more than 0.0002% Generally known conditions may be used as the atmosphere conditions including the type of nitriding gas. Further, the nitriding method is not limited to the gas nitriding shown here, and a generally known nitriding method can be applied, as in the case of carburizing.
[0049] 第二相として金属間化合物を利用する場合は、金属間化合物の全部または大部 分が溶解した状態から緩冷却とすることで、主として金属間化合物の成長により形成 を進行させることが本発明で好まし 、第二相形態を得るためには好都合である。この ためには、鋼板製造工程において、 900°C以上の温度力もの冷却過程において 90 0°Cから 500°Cまでの冷却速度を 20°CZ秒以下で冷却し、金属間化合物を体積率 で 2. 0倍以上増加させるようにする。冷却開始前の温度が低すぎると金属間化合物 の溶解が不十分となり、その後の成長が起きなくなる。また、冷却速度が速すぎると、 金属間化合物の核生成頻度が高くなり、異方性を持った成長がおきず、等方的な金 属間化合物が高密度に形成されることとなる。 [0049] When an intermetallic compound is used as the second phase, formation may proceed mainly by growth of the intermetallic compound by slowly cooling from a state in which all or most of the intermetallic compound is dissolved. Preferred in the present invention is convenient for obtaining the second phase form. For this purpose, in the steel plate manufacturing process, the cooling rate from 900 ° C to 500 ° C is cooled in 20 ° CZ seconds or less in the cooling process at a temperature of 900 ° C or higher, and the intermetallic compound is reduced in volume ratio. 2. Try to increase more than 0 times. If the temperature before the start of cooling is too low, intermetallic compounds Insufficient dissolution occurs and subsequent growth does not occur. On the other hand, if the cooling rate is too fast, the nucleation frequency of intermetallic compounds increases, and anisotropic growth does not occur, and isotropic intermetallic compounds are formed in high density.
ここで示した各種の第二相についての製造方法は、対象とする第二相を形成する 元素やその量により異なることは当然であり、上記の範囲に限定されるものでないこと は言うまでもない。第二相を形成する元素の種類、形成させる第二相の種類、量およ び制御すべき形態の方向性がわ力つていれば、適当な条件を見出すことは一般のメ タラジーの範疇であり、当業者であれば数度の試行の後にそれを確定することはさほ ど困難なことではない。  It goes without saying that the production methods for the various second phases shown here differ depending on the elements forming the second phase of interest and their amounts, and are not limited to the above ranges. Finding the right conditions is a general metric category, given the type of elements that form the second phase, the type and amount of the second phase to be formed, and the direction of the form to be controlled. It is not so difficult for those skilled in the art to determine it after several trials.
[0050] 薄手鋼板の製造においては、硬度調整や板厚調整のために再結晶焼鈍の後に再 冷延を行なう場合がある。この圧下率は、形状調整のために行なわれるスキンパスに 近い数％程度から、冷延と同様の 50%以上までが実用化されている。本発明に再冷 延法を適用する場合、本発明の効果は何ら損なわれるものではない。ただし、圧下 率が過度に高いと当然ではある力 均一伸びの絶対値は小さくなる。均一伸び領域 における加工硬化量も小さくなり、本発明効果を適用することを考えれば本来好まし い方法ではない。好ましくは 30%以下、さらに好ましくは 20%以下、好ましくは 10% 以下、好ましくは 3%以下とする。  [0050] In the manufacture of a thin steel plate, re-rolling may be performed after recrystallization annealing in order to adjust hardness or plate thickness. This rolling reduction has been put to practical use from a few percent close to the skin pass used for shape adjustment to 50% or more, which is the same as cold rolling. When the re-rolling method is applied to the present invention, the effects of the present invention are not impaired at all. However, if the rolling reduction is excessively high, the absolute value of the uniform force elongation that is natural is reduced. The amount of work hardening in the uniform elongation region is also reduced, and this is not an inherently preferred method in view of applying the effect of the present invention. Preferably it is 30% or less, more preferably 20% or less, preferably 10% or less, preferably 3% or less.
[0051] 本発明の効果は、成分調整以降、焼鈍前の熱履歴、製造履歴によらない。熱延を 行う場合のスラブはインゴット法、連続铸造法などの製造法には限定されず、また熱 延に至るまでの熱履歴にもよらないため、スラブ再加熱法、铸造したスラブを再加熱 することなく直接熱延する CC— DR法、さらには粗圧延などを省略した薄スラブ铸造 によっても本発明の効果を得ることができる。また熱延条件にもよらず、仕上げ温度を α + γの二相域とする二相域圧延や、粗バーを接合して圧延する連続熱延によって も本発明の効果が得られる。  [0051] The effect of the present invention does not depend on the heat history and the manufacturing history before the annealing after the component adjustment. Slabs for hot rolling are not limited to manufacturing methods such as the ingot method and continuous forging method, and do not depend on the heat history until hot rolling, so the slab reheating method and the forged slab are reheated. The effect of the present invention can also be obtained by CC-DR method in which hot rolling is performed directly without making a thin slab without rough rolling. In addition, the effect of the present invention can be obtained by two-phase rolling in which the finishing temperature is α + γ two-phase region or continuous hot rolling in which a rough bar is joined and rolled regardless of hot rolling conditions.
[0052] また、本発明鋼を、溶接部を有する素材として用いる場合には、熱影響部での均一 変形性を向上させ、くびれの発生を抑止できるため、特に好ましい。  [0052] Further, when the steel of the present invention is used as a material having a welded portion, it is particularly preferable because uniform deformation at the heat-affected zone can be improved and necking can be suppressed.
本発明鋼板は、何らかの表面処理を行って使用される場合も含む。本発明の範囲 内であれば、適用により表面処理により損なわれるものではない。表面処理としては 、金属めつきについては通常適用されている、錫、クロム (ティンフリー）、 Ni、亜鉛、 アルミなどが施される。また、近年使用されるようになっている有機皮膜を被覆したラミ ネート鋼板用の原板に関しても、本発明の効果を得ることが可能となる。 The steel sheet of the present invention includes a case where it is used after being subjected to some surface treatment. If it is within the scope of the present invention, it is not damaged by the surface treatment by application. As surface treatment For metal plating, tin, chromium (tin-free), Ni, zinc, aluminum, etc. are applied as usual. In addition, the effects of the present invention can be obtained with respect to an original sheet for a laminated steel sheet coated with an organic film that has been used in recent years.
用途としては、電機機器、電子部品、建材や金属容器全般に使用可能であり、これ 以外の分野でも何らかの用途において上述と同様の課題がある場合には適用が可 能であることは言うまでもな!/、。  Needless to say, it can be used for electrical equipment, electronic parts, building materials, and metal containers in general, and can be applied in other fields if there are problems similar to the above in some applications! / ,.
実施例  Example
[0053] 表 1に示す各成分の鋼について、熱間圧延、冷間圧延、再結晶焼鈍、再冷延を行 つて各種鋼板を製造し、各種の評価試験を行った。第二相は、 SEMおよび TEMを 用いて鋼板の断面、鋼板薄膜、抽出レプリカおよび電解抽出残渣により観察した。ま た、 EDXを用いて第二相に含まれる元素を定性分析した。材質特性は、圧延方向の JIS5号引張試験片による引張試験およびロックウェル表面硬度によって測定した。 測定結果および評価は、表 2〜表 5に示す。各表中の用語の意味を以下に示す。 「平均長径」、「平均短径」：平均長径が 0. 10 m以上、平均短径が 0. 05 /z m以 上、平均長径 Z平均短径≥2. 0を満たす第二相について、偏りのないように十分な 数について測定した際の、各々の平均値。  [0053] With respect to the steel of each component shown in Table 1, various steel sheets were manufactured by performing hot rolling, cold rolling, recrystallization annealing, and recold rolling, and various evaluation tests were performed. The second phase was observed by means of SEM and TEM for the cross section of the steel sheet, the steel sheet thin film, the extraction replica and the electrolytic extraction residue. In addition, the elements contained in the second phase were qualitatively analyzed using EDX. Material properties were measured by a tensile test using a JIS No. 5 tensile specimen in the rolling direction and a Rockwell surface hardness. The measurement results and evaluation are shown in Table 2 to Table 5. The meanings of the terms in each table are shown below. “Average major axis”, “Average minor axis”: The second phase satisfying the condition that the average major axis is 0.10 m or more, the average minor axis is 0.05 / zm or more, the average major axis Z the average minor axis ≥2.0 The average value when measuring a sufficient number so that there is no.
「平均長径 Z平均短径」：「平均長径」、「平均短径」の比。発明効果の根源となって V、る酸ィ匕物の異方性の程度を示す指標となる。  “Average major axis Z Average minor axis”: Ratio of “average major axis” and “average minor axis”. It becomes an index indicating the degree of anisotropy of V, which is the root of the invention effect.
「含有元素」：本発明の特徴を示す第二相から検出された元素。  “Contained element”: an element detected from the second phase showing the characteristics of the present invention.
「方位」：第二相の平均長径の方向と、その第二相が接している主相の結晶方位と の関係。方位に関連がある場合、主相の結晶方位を示す。  “Orientation”: The relationship between the direction of the average major axis of the second phase and the crystal orientation of the main phase in contact with the second phase. When the orientation is related, the crystal orientation of the main phase is indicated.
「フランジ成形性」：平板を円筒形状に丸めて溶接した 3ピース缶の胴部を 10000 缶分用意する。そして、これらに対して金型を用いてフランジ成形を行い、その結果、 破断せずに全缶フランジ成型できた場合に合格、 1缶でも破断した場合に不合格と する。  “Flange formability”: Prepare 10,000 barrels of 3-piece can body that is made by rounding a flat plate into a cylindrical shape and welding. For these, flange molding is performed using a mold. As a result, if all can flanges can be molded without breaking, it will be accepted. If even one can breaks, it will be rejected.
「評価」：通常レベル: C、優れる： B、著しく優れる: A。 Aと Bを本発明とする。  “Evaluation”: normal level: C, excellent: B, markedly excellent: A. A and B are the present invention.
[0054] (実施例 1)第二相を酸化物とした場合の実験結果を、表 2に示す。酸化物の形態は 、主として、铸造条件による酸化物サイズと熱延条件による延伸量で制御した。酸ィ匕 物の「数密度」は SEMでの断面観察により求めた。酸化物の状態を本発明の範囲内 に制御することで、良好な均一伸びが得られて ヽることが確認できる。 (Example 1) Table 2 shows the experimental results when the second phase is an oxide. The form of the oxide was controlled mainly by the oxide size according to the forging conditions and the stretching amount according to the hot rolling conditions. Acid The “number density” of the object was determined by cross-sectional observation with SEM. It can be confirmed that good uniform elongation can be obtained by controlling the state of the oxide within the range of the present invention.
(実施例 2)第二相を硫ィ匕物とした場合の実験結果を表 3に示す。硫化物の形態は、 主として、铸造条件による硫化物サイズと熱延条件による延伸量で制御した。硫ィ匕物 の「数密度」は TEM観察により求めた。硫ィ匕物の状態を本発明の範囲内に制御する ことで、良好な均一伸びが得られて 、ることが確認できる。  (Example 2) Table 3 shows the experimental results when the second phase is a sulfate. The form of the sulfide was controlled mainly by the sulfide size according to the forging conditions and the drawing amount by the hot rolling conditions. The “number density” of the sulfide was determined by TEM observation. It can be confirmed that good uniform elongation can be obtained by controlling the state of the sulfide within the range of the present invention.
[0055] (実施例 3)第二相を炭化物または窒化物とした場合の実験結果を表 4に示す。炭化 物または窒化物の形態は、主として、浸炭または窒化条件で制御した。本実施例で「 素板」はすべて 700°Cで再結晶焼鈍した鋼板である。比較材として、浸炭'窒化を行 わず再冷延により、浸炭または窒化した板と同程度の硬さにしたものについても特性 を示している。炭化物または窒化物は、板厚 1Z8位置と板厚中心で観察した。炭化 物または窒化物の「数密度」は、板厚表層 1Z8または板厚中心層 1Z4を電解した 際の残渣を SEM観察して求めた。表 4中の第二相に関する「体積分率」、「数密度」 、および主相に関する値は、板厚表層 1Z8についてのものである。炭化物または窒 化物の状態を本発明の範囲内に制御することで、良好な均一伸びが得られているこ とが確認できる。 Example 3 Table 4 shows the experimental results when the second phase is carbide or nitride. The carbide or nitride morphology was controlled primarily by carburizing or nitriding conditions. In this example, all the “base plates” are steel plates recrystallized and annealed at 700 ° C. As a comparative material, the characteristics are also shown for a material that has been hardened to the same degree as a carburized or nitrided plate by re-rolling without carburizing and nitriding. Carbide or nitride was observed at the plate thickness 1Z8 position and the plate thickness center. The “number density” of carbide or nitride was determined by SEM observation of the residue when the plate thickness surface layer 1Z8 or plate thickness center layer 1Z4 was electrolyzed. The values related to “volume fraction”, “number density”, and main phase in the second phase in Table 4 are for the plate thickness surface layer 1Z8. It can be confirmed that good uniform elongation is obtained by controlling the state of the carbide or nitride within the range of the present invention.
(実施例 4)第二相を金属間化合物とした場合の実験結果を表 5に示す。金属間化合 物を Ni A1とし、その形態は、主として、再結晶焼鈍条件、特に焼鈍温度による溶体 (Example 4) Table 5 shows the experimental results when the second phase was an intermetallic compound. The intermetallic compound is Ni A1, and its form is mainly the solution due to recrystallization annealing conditions, especially the annealing temperature.
3 Three
化の程度とその後の冷却過程による核生成 *成長で制御した。本実施例で「素板」は すべて冷延したままの鋼板である。 Ni A1の「数密度」は TEM観察により求めた。例 1  Controlled by degree of nucleation and subsequent nucleation * growth by cooling process. In this example, all the “element plates” are steel plates that have been cold-rolled. The “number density” of Ni A1 was determined by TEM observation. Example 1
3  Three
〜例 4に示した本発明外の鋼板と比較すれば、金属間化合物の状態を本発明の範 囲内に好ましく制御することで、良好な特性が得られることが確認できる。  Compared with the steel sheet outside the present invention shown in Example 4, it can be confirmed that favorable characteristics can be obtained by preferably controlling the state of the intermetallic compound within the scope of the present invention.
[0056] [表 1] 〔0057 [0056] [Table 1] [0057
Figure imgf000023_0001
Figure imgf000023_0001
〔〕0058 [] 0058
Figure imgf000024_0001
Figure imgf000024_0001
* 1 :1000°C以上かつ歪速度 1/秒以上の条件での真歪の総和 * 2: 1000 以下かつ歪速度 10 秒以上の条件での真歪の総和 * 1: Total true strain under the condition of 1000 ° C or higher and strain rate of 1 / second or higher * 2: Total true strain under the condition of 1000 or lower and strain rate of 10 seconds or higher
〔〕0059 [] 0059
Figure imgf000025_0001
Figure imgf000025_0001
* 1： 1000°C以上かつ歪速度 1/秒以上の条件での真歪の総和 * 2: 1000¾以下かつ歪速度 10/秒以上の条件での真歪の総和 * 1: Sum of true strain at 1000 ° C or more and strain rate of 1 / sec or more * 2: Sum of true strain at conditions of 1000¾ or less and strain rate of 10 / sec or more
s〔sa006 s [sa006
Figure imgf000026_0001
Figure imgf000026_0001
* 1： ((¾炭時間（秒)） * (浸炭温度 /【（浸 1¾性ガス滾度（％)) * (浸炭処理での冷却速度 (¾ 秒)） 1 *2: (板厚表層 1ノ 8での体積率) (板厚中心層 1ノ 4での体積率）  * 1: ((¾ carburizing time (sec)) * (Carburizing temperature / [(Carburizing 1¾ gas concentration (%)) * (Cooling rate in carburizing treatment (¾ sec)) 1 * 2: (Thickness surface layer (Volume ratio at 1 to 8) (Volume ratio at thickness center layer 1 to 4)
*3: (板厚表餍 1/8での数密度）/ (板厚中心層 1/4での数密度） * 3: (Number density at plate thickness table 1/8) / (Number density at 1/4 thickness center layer)
Figure imgf000027_0001
Figure imgf000027_0001
* 1：再結晶焼鈍前後での体積分率増加比 * 1: Volume fraction increase ratio before and after recrystallization annealing
産業上の利用可能性 Industrial applicability
本発明によれば、同じ強度、同じ全伸びであっても、高い均一伸びを有し、より高歪 域まで局部変形 (くびれ)の発生を抑えた硬質極薄手材を得ることができる。  According to the present invention, it is possible to obtain a hard ultrathin material having high uniform elongation even with the same strength and the same total elongation, and suppressing the occurrence of local deformation (necking) to a higher strain range.

Claims

請求の範囲 The scope of the claims
[1] 板厚が 0.400mm以下の硬質極薄鋼板であって、  [1] A hard ultra-thin steel plate with a thickness of 0.400 mm or less,
質量％で、  % By mass
じ：0%以上かっ0.800%以下、  J: 0% to 0.800%,
?^:0%以上かっ0.600%以下、  ? ^: 0% to 0.600%,
Si :0%以上かつ 2.0%以下、  Si: 0% or more and 2.0% or less,
Mn:0%以上かつ 2.0%以下、  Mn: 0% or more and 2.0% or less,
：0%以上かっ0.10%以下、  : 0% or more and 0.10% or less,
3:0%以上かっ0. 100%以下、  3: 0% or more, 0.100% or less,
A1:0%以上かつ 3.0%以下、  A1: 0% or more and 3.0% or less,
0:0%以上かっ0.200%以下を含有し、  0: 0% or more and 0.200% or less,
平均長径が 0.10 m以上かつ平均短径が 0.05 m以上で、さらに平均長径 平均短径≥2.0である第二相が、体積分率で、 0.05%以上含有されている ことを特徴とする硬質極薄鋼板。  A hard electrode characterized in that the second phase having an average major axis of 0.10 m or more, an average minor axis of 0.05 m or more, and an average major axis of average minor axis ≥2.0 is contained in a volume fraction of 0.05% or more. Thin steel plate.
[2] 請求項 1に記載の硬質極薄鋼板であって、 [2] The hard ultra-thin steel sheet according to claim 1,
Ti:0%以上かつ 4.00%以下、  Ti: 0% or more and 4.00% or less,
Nb:0%以上かつ 4.00%以下、  Nb: 0% or more and 4.00% or less,
REM :0%以上かつ 4.00%以下、 REM: 0% or more and 4.00% or less,
:0%以上かっ0.0300%以下、  : 0% or more and 0.0300% or less,
Cu:0%以上かつ 8.00%以下、  Cu: 0% or more and 8.00% or less,
じ&:0%以上かっ1.00%以下、  J & 0% to 1.00%
Ni:0%以上かつ 8.00%以下、  Ni: 0% or more and 8.00% or less,
Cr:0%以上かつ 20.00%以下、  Cr: 0% or more and 20.00% or less,
の一種または二種以上をさらに含有する。  1 type or 2 types or more are further contained.
[3] 請求項 1に記載の硬質極薄鋼板であって、 [3] The hard ultra-thin steel sheet according to claim 1,
平均長径が 0.5 μ m以上かつ平均短径が 0.1 μ m以上で、さらに平均長径 Z 均短径≥2.0である第二相の数密度力 0.01個 Z m2以上である。 An average major axis of 0.5 mu m or more and an average minor diameter of 0.1 mu m or more, and further the average major axis Z Hitoshitan径0.01 or number density force of ≥2.0 in which the second phase Z m 2 or more.
[4] 請求項 1に記載の硬質極薄鋼板であって、 平均長径が 0. 5 μ m以上かつ平均短径が 0. 1 μ m以上で、さらに平均長径 Z平 均短径≥2. 0である第二相の数密度力 0. 001個 Z m3以上である。 [4] The hard ultra-thin steel sheet according to claim 1, Number density force of the second phase with an average major axis of 0.5 μm or more and an average minor axis of 0.1 μm or more, and an average major axis Z average minor axis ≥2.0 0.001 Z m 3 That's it.
[5] 請求項 1に記載の硬質極薄鋼板であって、 [5] The hard ultra-thin steel sheet according to claim 1,
主相が Feのフェライト相でかつ体積率が 80%以上である。  The main phase is the ferrite phase of Fe and the volume fraction is 80% or more.
[6] 請求項 1に記載の硬質極薄鋼板であって、 [6] The hard ultra-thin steel sheet according to claim 1,
平均長径が 0. 5 μ m以上かつ平均短径が 0. 1 μ m以上で、さらに平均長径 Z平 均短径≥2. 0である第二相の平均長径の方向がこの第二相が接している Fe相のく 100 >方位またはく 110 >方位である。  The direction of the average major axis of the second phase in which the average major axis is 0.5 μm or more and the average minor axis is 0.1 μm or more and the average major axis Z average minor axis ≥2.0 is the second phase. The Fe phase in contact is either 100> orientation or 110> orientation.
[7] 請求項 1に記載の硬質極薄鋼板であって、 [7] The hard ultra-thin steel sheet according to claim 1,
平均長径が 0. 5 μ m以上かつ平均短径が 0. 1 μ m以上で、さらに平均長径 Z平 均短径≥2. 0である第二相が、酸化物、硫化物、炭化物、窒化物、金属間化合物の 単体または複合ィ匕合物である。  A second phase having an average major axis of 0.5 μm or more and an average minor axis of 0.1 μm or more and an average major axis Z average minor axis ≥2.0 is an oxide, sulfide, carbide, or nitride. Or a single or composite compound of intermetallic compounds.
[8] 請求項 7に記載の硬質極薄鋼板であって、 [8] The hard ultra-thin steel sheet according to claim 7,
平均長径が 0. 5 μ m以上かつ平均短径が 0. 1 μ m以上で、さらに平均長径 Z平 均短径≥2. 0である第二相が、 Fe、 Mn、 Si、 Al、 Cr、 REM, Ti、 Nbの一種または 二種を含有する酸化物である。  The second phase with an average major axis of 0.5 μm or more, an average minor axis of 0.1 μm or more, and an average major axis Z average minor axis ≥2.0 is Fe, Mn, Si, Al, Cr An oxide containing one or two of REM, Ti and Nb.
[9] 請求項 7に記載の硬質極薄鋼板であって、 [9] The hard ultra-thin steel sheet according to claim 7,
平均長径が 0. 5 μ m以上かつ平均短径が 0. 1 μ m以上で、さらに平均長径 Z平 均短径≥2. 0である第二相が、 Ti、 Mn、 Cu、 Ca、 REMの一種または二種を含有 する硫ィ匕物である。  The second phase with an average major axis of 0.5 μm or more and an average minor axis of 0.1 μm or more and an average major axis Z average minor axis ≥2.0 is Ti, Mn, Cu, Ca, REM. This is a sulfur containing one or two of these.
[10] 請求項 7に記載の硬質極薄鋼板であって、 [10] The hard ultra-thin steel sheet according to claim 7,
平均長径が 0. 5 μ m以上かつ平均短径が 0. 1 μ m以上で、さらに平均長径 Z平 均短径≥2. 0である第二相が、 Fe、 Ti、 Nb、 Si、 Crの一種または二種を含有する炭 化物である。  The second phase with an average major axis of 0.5 μm or more, an average minor axis of 0.1 μm or more, and an average major axis Z average minor axis ≥2.0 is Fe, Ti, Nb, Si, Cr A carbide containing one or two of the above.
[11] 請求項 7に記載の硬質極薄鋼板であって、  [11] The hard ultra-thin steel sheet according to claim 7,
平均長径が 0. 5 μ m以上かつ平均短径が 0. 1 μ m以上で、さらに平均長径 Z平 均短径≥2. 0である第二相が、 Fe、 Ti、 Nb、 Al、 B、 Crの一種または二種を含有す る窒化物である。 A second phase with an average major axis of 0.5 μm or more and an average minor axis of 0.1 μm or more and an average major axis Z average minor axis ≥2.0 is Fe, Ti, Nb, Al, B A nitride containing one or two of Cr.
[12] 請求項 7に記載の硬質極薄鋼板であって、 [12] The hard ultra-thin steel sheet according to claim 7,
平均長径が 0. 5 μ m以上かつ平均短径が 0. 1 μ m以上で、さらに平均長径 Z平 均短径≥2. 0である第二相が、 Fe、 Ti、 Nb、 Al、 Si、 Mnの一種または二種を含有 する金属間化合物である。  The second phase with an average major axis of 0.5 μm or more and an average minor axis of 0.1 μm or more and an average major axis Z average minor axis ≥2.0 is Fe, Ti, Nb, Al, Si An intermetallic compound containing one or two of Mn.
[13] 請求項 1に記載の硬質極薄鋼板であって、 [13] The hard ultra-thin steel sheet according to claim 1,
平均長径が 0. 5 μ m以上かつ平均短径が 0. 1 μ m以上で、さらに平均長径 Z平 均短径≥2. 0である第二相の体積率が、（板厚表層 1Z8での体積率) Z (板厚中心 層 1Z4での体積率）≥ 10である。  The volume fraction of the second phase with an average major axis of 0.5 μm or more and an average minor axis of 0.1 μm or more, and an average major axis Z average minor axis ≥2.0 (in the thickness layer 1Z8) Volume ratio) Z (volume ratio in thickness center layer 1Z4) ≥10.
[14] 請求項 1に記載の硬質極薄鋼板であって、 [14] The hard ultra-thin steel sheet according to claim 1,
平均長径が 0. 5 μ m以上かつ平均短径が 0. 1 μ m以上で、さらに平均長径 Z平 均短径≥2. 0である第二相の数密度が、（板厚表層 1Z8での数密度) Z (板厚中心 層 1Z4での数密度）≥ 10である。  The number density of the second phase with an average major axis of 0.5 μm or more and an average minor axis of 0.1 μm or more and an average major axis Z average minor axis ≥2.0 Number density) Z (number density in thickness center layer 1Z4) ≥10.
[15] 請求項 1に記載の硬質極薄鋼板であって、 [15] The hard ultra-thin steel sheet according to claim 1,
幅 25mmで長さ 60mmの平行部を有する引張試験片を用いて、評点間距離を 50 mm、変形速度を 5mmZ分とする引張試験における最高強度≥350MPa、かつ、口 ックウエノレ硬度 HR30T≥ 54である。  Using a tensile test piece with a parallel part of 25 mm in width and 60 mm in length, the maximum strength ≥350 MPa in the tensile test with a distance between grades of 50 mm and a deformation rate of 5 mmZ, and a mouth were hardness of HR30T≥54 .
[16] 請求項 1に記載の硬質極薄鋼板であって、 [16] The hard ultra-thin steel sheet according to claim 1,
幅 25mmで長さ 60mmの平行部を有する引張試験片を用いて、評点間距離を 50 mm、変形速度を 5mmZ分とする引張試験において、均一伸び Z局部伸び≥1. 0 である。  In a tensile test using a tensile test piece having a parallel part of 25 mm in width and 60 mm in length, with a distance between grades of 50 mm and a deformation rate of 5 mmZ, uniform elongation Z local elongation ≥1.0.
[17] 請求項 1に記載の硬質極薄鋼板であって、  [17] The hard ultrathin steel sheet according to claim 1,
幅 25mmで長さ 60mmの平行部を有する引張試験片を用いて、評点間距離を 50 mm、変形速度を 5mmZ分とする引張試験において、降伏応力 Z最高強度≤0. 9 である。  Yield stress Z maximum strength ≤ 0.9 in a tensile test using a tensile test piece having a parallel part of 25 mm in width and 60 mm in length with a distance between grades of 50 mm and a deformation rate of 5 mmZ.
[18] 請求項 8に記載の硬質極薄鋼板を製造する方法であって、  [18] A method for producing the hard ultrathin steel sheet according to claim 8,
厚さ 50mm以上かつ鋼片中の酸化物の平均直径が 10 μ m〜25 μ mの鋼片を 60 0°C以上の熱間で圧延加工する際に、  When rolling a steel slab having a thickness of 50 mm or more and an average diameter of oxide in the slab of 10 μm to 25 μm at a temperature of 600 ° C. or higher,
1000°C以上かつ歪速度 1Z秒以上の条件での真歪の総和が 0. 4以上の圧延を 行なった後に、 Rolling with a total true strain of 0.4 or more under conditions of 1000 ° C or more and strain rate of 1Z seconds or more After doing
1000°C以下かつ歪速度 ΙΟΖ秒以上の条件での真歪の総和が 0. 7以上の圧延を 行なう  Rolling with a total true strain of 0.7 or more under conditions of 1000 ° C or less and strain rate of leap seconds or more
ことを特徴とする硬質極薄鋼板の製造方法。  The manufacturing method of the hard ultra-thin steel plate characterized by the above-mentioned.
[19] 請求項 9に記載の硬質極薄鋼板を製造する方法であって、 [19] A method for producing the hard ultrathin steel sheet according to claim 9,
厚さ 50mm以上かつ鋼片中の硫化物の平均直径が 10 μ m〜25 μ mの鋼片を 60 0°C以上の熱間で圧延加工する際に、  When rolling a steel slab having a thickness of 50 mm or more and an average diameter of sulfide in the steel slab of 10 μm to 25 μm at a temperature of 600 ° C. or higher,
1000°C以上かつ歪速度 1Z秒以上の条件での真歪の総和が 0. 4以上の圧延を 行なった後に、  After rolling with a total true strain of 0.4 or more under the condition of 1000 ° C or more and strain rate of 1Z seconds or more,
1000°C以下かつ歪速度 10Z秒以上の条件での真歪の総和が 0. 7以上の圧延を 行なう  Rolling with a total true strain of 0.7 or more under conditions of 1000 ° C or less and strain rate of 10Z seconds or more
ことを特徴とする硬質極薄鋼板の製造方法。  The manufacturing method of the hard ultra-thin steel plate characterized by the above-mentioned.
[20] 請求項 10に記載の硬質極薄鋼板を製造する方法であって、 [20] A method for producing the hard ultrathin steel sheet according to claim 10,
冷延後、再結晶焼鈍と同時またはその後に、 600〜700°Cの温度域で、 { (浸炭時 間 (秒) ) * (浸炭温度 (°C) ) }/{ (浸炭性ガス濃度 (％) ) * (浸炭処理での冷却速度 After cold rolling, simultaneously with or after recrystallization annealing, in the temperature range of 600 to 700 ° C, {(carburizing time (seconds)) * (carburizing temperature (° C))} / {(carburizing gas concentration ( %)) * (Cooling rate in carburizing process
(°CZ秒)） }≥20なる条件で浸炭処理を行い、 C量を 0. 0002%以上増加させる ことを特徴とする硬質極薄鋼板の製造方法。 (° CZ seconds))} A method for producing a hard ultra-thin steel sheet, characterized by performing carburizing treatment under the condition of ≥20 and increasing the C content by 0.0002% or more.
[21] 請求項 11に記載の硬質極薄鋼板を製造する方法であって、 [21] A method for producing the hard ultrathin steel sheet according to claim 11,
冷延後、再結晶焼鈍と同時またはその後に、 600〜700°Cの温度域で、 { (窒化時 間 (秒) ) * (窒化温度 (°C) ) }/{ (窒化性ガス濃度 (％) ) * (窒化処理での冷却速度 After cold rolling, at the same time as or after recrystallization annealing, in the temperature range of 600 to 700 ° C, {(nitriding time (seconds)) * (nitriding temperature (° C))} / {(nitriding gas concentration ( %)) * (Cooling rate in nitriding treatment
(°CZ秒)） }≥20なる条件で窒化処理を行い、 N量を 0. 0002%以上増加させること を特徴とする硬質極薄鋼板の製造方法。 (° CZ seconds)) A method for producing a hard ultra-thin steel sheet, characterized by performing nitriding under the condition of ≥20 and increasing the N content by 0.0002% or more.
[22] 請求項 12に記載の硬質極薄鋼板を製造する方法であって、 [22] A method for producing the hard ultrathin steel sheet according to claim 12,
鋼板製造工程にお 、て、 900°C以上の温度力もの冷却過程にぉ 、て 900°Cから 5 In the steel plate manufacturing process, from 900 ° C to 5 °
00°Cまでの冷却速度を 20°CZ秒以下で冷却し、金属間化合物を体積率で 2. 0倍 以上増加させる Cool the cooling rate to 00 ° C within 20 ° CZ seconds and increase intermetallic compounds by 2.0 times or more in volume ratio.
ことを特徴とする硬質極薄鋼板の製造方法。  The manufacturing method of the hard ultra-thin steel plate characterized by the above-mentioned.
PCT/JP2007/057575 2006-04-04 2007-04-04 Very thin hard steel sheet and method for producing the same WO2007116913A1 (en)

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009280847A (en) * 2008-05-21 2009-12-03 Nippon Steel Corp Hard extra-thin steel sheet having reduced local deformability, and method for producing the same
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WO2012005330A1 (en) * 2010-07-09 2012-01-12 新日本製鐵株式会社 Ni-CONTAINING STEEL SHEET AND PROCESS FOR PRODUCING SAME
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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02118026A (en) 1988-10-28 1990-05-02 Kawasaki Steel Corp Manufacture of steel sheet for can
JPH03257123A (en) 1990-03-06 1991-11-15 Nippon Steel Corp Production of steel sheet for extremely thin welded can having excellent blank layout property
JPH1072640A (en) 1996-08-30 1998-03-17 Kawasaki Steel Corp Steel sheet for can, increased in age hardenability and excellent in material stability, and its production
JP2001123245A (en) * 1999-10-21 2001-05-08 Nippon Steel Corp High toughness and high tensile strength steel excellent in weld zone toughness and producing method therefor
JP2002003987A (en) * 2000-06-26 2002-01-09 Nippon Steel Corp Low-yield ratio, high-tensile steel excellent in weldability and toughness at low temperature, and its manufacturing method
JP2004162150A (en) * 2002-11-15 2004-06-10 Nippon Steel Corp Steel and steel welded member having excellent toughness in weld heat affected zone
JP2005248281A (en) * 2004-03-05 2005-09-15 Kobe Steel Ltd High strength cold rolled steel sheet having excellent adhesion of coating film
JP2006102766A (en) 2004-10-04 2006-04-20 Shinko Kiki Kk Handy type cap tip dismounting device

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1276987C (en) * 2001-10-19 2006-09-27 住友金属工业株式会社 Thin steel plate with excellent workability and forming precision and producing process thereof
CN1292089C (en) * 2001-10-29 2006-12-27 新日本制铁株式会社 Steel sheet for vitreous enameling and method for producing the same
KR100733016B1 (en) * 2002-06-17 2007-06-27 제이에프이 스틸 가부시키가이샤 FERRITIC STAINLESS STEEL PLATE WITH Ti AND METHOD FOR PRODUCTION THEREOF
EP1806420A4 (en) * 2004-09-09 2008-04-23 Nippon Steel Corp Steel sheet for extremely thin container and method for production thereof
EP2671960B1 (en) * 2005-03-31 2017-11-01 Kabushiki Kaisha Kobe Seiko Sho High strength cold-rolled steel sheet and automobile components of steel having excellent properties in coating film adhesion, workability, and hydrogen embrittlement resistivity
EP1950317B1 (en) * 2005-11-09 2016-03-30 Nippon Steel & Sumitomo Metal Corporation Steel sheet for continuous cast enameling with excellent resistance to fishscaling and process for producing the same

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02118026A (en) 1988-10-28 1990-05-02 Kawasaki Steel Corp Manufacture of steel sheet for can
JPH03257123A (en) 1990-03-06 1991-11-15 Nippon Steel Corp Production of steel sheet for extremely thin welded can having excellent blank layout property
JPH1072640A (en) 1996-08-30 1998-03-17 Kawasaki Steel Corp Steel sheet for can, increased in age hardenability and excellent in material stability, and its production
JP2001123245A (en) * 1999-10-21 2001-05-08 Nippon Steel Corp High toughness and high tensile strength steel excellent in weld zone toughness and producing method therefor
JP2002003987A (en) * 2000-06-26 2002-01-09 Nippon Steel Corp Low-yield ratio, high-tensile steel excellent in weldability and toughness at low temperature, and its manufacturing method
JP2004162150A (en) * 2002-11-15 2004-06-10 Nippon Steel Corp Steel and steel welded member having excellent toughness in weld heat affected zone
JP2005248281A (en) * 2004-03-05 2005-09-15 Kobe Steel Ltd High strength cold rolled steel sheet having excellent adhesion of coating film
JP2006102766A (en) 2004-10-04 2006-04-20 Shinko Kiki Kk Handy type cap tip dismounting device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP2003221A4 *

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009280847A (en) * 2008-05-21 2009-12-03 Nippon Steel Corp Hard extra-thin steel sheet having reduced local deformability, and method for producing the same
CN102317490A (en) * 2009-03-30 2012-01-11 新日本制铁株式会社 Carburized steel part
JP2011241456A (en) * 2010-05-20 2011-12-01 Sumitomo Metal Ind Ltd Hot-dip-plated hot-rolled steel sheet and method of manufacturing the same
WO2012005330A1 (en) * 2010-07-09 2012-01-12 新日本製鐵株式会社 Ni-CONTAINING STEEL SHEET AND PROCESS FOR PRODUCING SAME
JP4975888B2 (en) * 2010-07-09 2012-07-11 新日本製鐵株式会社 Ni-added steel sheet and manufacturing method thereof
US8882942B2 (en) 2010-07-09 2014-11-11 Nippon Steel & Sumitomo Metal Corporation Ni-added steel plate and method of manufacturing the same
US9260771B2 (en) 2011-09-28 2016-02-16 Nippon Steel & Sumitomo Metal Corporation Ni-added steel plate and method of manufacturing the same
WO2013168770A1 (en) * 2012-05-10 2013-11-14 日立金属株式会社 Austenitic heat-resistant cast steel having excellent machinability, and part for exhaust system which comprises same
JPWO2013168770A1 (en) * 2012-05-10 2016-01-07 日立金属株式会社 Austenitic heat-resistant cast steel with excellent machinability and exhaust system parts composed thereof
US9765678B2 (en) 2012-05-10 2017-09-19 Hitachi Metals, Ltd. Heat-resistant, austenitic cast steel having excellent machinability and exhaust member made thereof
WO2020111739A3 (en) * 2018-11-30 2020-08-13 주식회사 포스코 Cold-rolled steel plate for enameling and method for manufacturing same

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