Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
  • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
  • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
  • H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
  • H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
  • H01F1/147—Alloys characterised by their composition
  • H01F1/14766—Fe-Si based alloys
  • H01F1/14791—Fe-Si-Al based alloys, e.g. Sendust
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  • C21D6/00—Heat treatment of ferrous alloys
  • C21D6/008—Heat treatment of ferrous alloys containing Si
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  • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
  • C21D8/02—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
  • C21D8/0221—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
  • C21D8/0226—Hot rolling
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  • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
  • C21D8/02—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
  • C21D8/0221—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
  • C21D8/0236—Cold rolling
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
  • C21D8/02—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
  • C21D8/0247—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
  • C21D8/0268—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment between cold rolling steps
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  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
  • C21D8/02—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
  • C21D8/0247—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
  • C21D8/0273—Final recrystallisation annealing
• • C—CHEMISTRY; METALLURGY
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  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
  • C21D8/12—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
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  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
  • C21D8/12—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
  • C21D8/1216—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties characterised by the working steps
  • C21D8/1233—Cold rolling
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
  • C21D8/12—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
  • C21D8/1244—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties characterised by the heat treatment
  • C21D8/1272—Final recrystallisation annealing
• • C—CHEMISTRY; METALLURGY
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  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/004—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
  • C22C38/008—Ferrous alloys, e.g. steel alloys containing tin
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
• • 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
  • C22C38/10—Ferrous alloys, e.g. steel alloys containing cobalt
• • 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
  • C22C38/10—Ferrous alloys, e.g. steel alloys containing cobalt
  • C22C38/105—Ferrous alloys, e.g. steel alloys containing cobalt containing Co and Ni
• • 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
  • C22C38/16—Ferrous alloys, e.g. steel alloys containing 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
  • C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
  • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
  • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
  • H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
  • H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
  • H01F1/147—Alloys characterised by their composition
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
  • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
  • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
  • H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
  • H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
  • H01F1/147—Alloys characterised by their composition
  • H01F1/14766—Fe-Si based alloys
  • H01F1/14775—Fe-Si based alloys in the form of sheets
• • 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
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P10/00—Technologies related to metal processing
  • Y02P10/20—Recycling

Definitions

• the present invention relates to a non-oriented electrical steel sheet. This application claims priority based on Japanese Patent Application No. 2022-151497 filed in Japan on September 22, 2022, the contents of which are incorporated herein.
• Electrical steel sheets are used as materials for the cores of electrical equipment.
• Examples of electrical equipment include drive motors installed in automobiles, motors for various compressors such as those used in air conditioners and refrigerators, and generators for household or industrial use. These electrical devices are required to have high energy efficiency, miniaturization, and high output. Therefore, low core loss and high magnetic flux density are required of electromagnetic steel sheets used as cores of electrical equipment.
• Texture control is a solution, and until now it has been compared by rolling processes in hot rolling and cold rolling, which have an axis of easy magnetization within the plane of the steel sheet, which is advantageous for improving magnetic properties, and is an essential process in steel sheet manufacturing.
• a technique has been proposed to develop a tissue ( ⁇ fiber) that can easily increase the accumulation. Specifically, a structure in which the ⁇ 110> direction is substantially parallel to the rolling direction (RD) is formed.
• Patent Documents 1 to 3 all disclose methods for developing ⁇ 100 ⁇ 011> orientation, and describe that the transformation temperature is lowered and the structure is refined by rapid cooling after hot rolling. .
• Patent Document 1 states that cooling to 250°C or less at a cooling rate of 200°C/sec or more within 3 seconds after hot rolling, and annealing between hot rolling and cold rolling. It is described that the cumulative rolling reduction rate in cold rolling is not less than 88%. It is said that this makes it possible to produce an electromagnetic steel sheet that is integrated in the ⁇ 100 ⁇ 011> orientation on the surface of the steel sheet.
• Patent Document 2 discloses a method for manufacturing an electrical steel sheet containing Al in an amount of 0.6% by mass or more and 3.0% by mass or less, in which the steel plate surface is It is described that an electrical steel sheet in which ⁇ 100 ⁇ 011> orientations are accumulated can be manufactured.
• Patent Document 3 discloses that the finish rolling temperature in hot rolling is set to be equal to or higher than the Ac3 transformation point, and the steel sheet temperature is cooled to 250°C within 3 seconds after hot rolling, or the finish rolling temperature is set to Ac3 transformation point -50. It is described that the temperature is below 0.degree. Furthermore, the manufacturing method described in Patent Document 3 performs cold rolling twice with intermediate annealing in between, and does not perform annealing between the hot rolling and the first cold rolling. The cumulative reduction rate is 5 to 15% during cold rolling. It is said that this makes it possible to produce an electromagnetic steel sheet that is integrated in the ⁇ 100 ⁇ 011> orientation on the surface of the steel sheet.
• Patent Documents 4 to 7 all disclose techniques for developing ⁇ 411 ⁇ orientation, such as optimizing the grain size in hot rolled sheets and It has been described that it strengthens the ⁇ fibers in the texture of the plate.
• Patent Document 4 cold rolling is performed on a hot rolled plate in which the degree of accumulation in the ⁇ 211 ⁇ direction is higher than the degree of accumulation in the ⁇ 411 ⁇ direction, and the cumulative reduction rate in the cold rolling is 80% or more. It is said that this makes it possible to manufacture an electromagnetic steel sheet that is integrated in the ⁇ 411 ⁇ direction on the surface of the steel sheet.
• Patent Documents 5 and 6 state that the slab heating temperature is 700°C or more and 1150°C or less, the finish rolling start temperature is 650°C or more and 850°C or less, and the finish rolling end temperature is 550°C or more and 800°C or less, and furthermore, the cold rolling It is described that the cumulative rolling reduction rate in the steel sheet is 85 to 95%. It is said that this makes it possible to produce an electromagnetic steel sheet in which the ⁇ 100 ⁇ and ⁇ 411 ⁇ orientations are integrated on the surface of the steel sheet.
• Patent Document 7 discloses that when alpha fibers are developed in a steel plate of a hot-rolled coil to the vicinity of the surface layer of the steel plate by strip casting or the like, the ⁇ h11 ⁇ 1/h12> orientation, especially ⁇ 100 ⁇ 012> to ⁇ 411 ⁇ 148> orientations are described to be recrystallized.
• the in-plane orientation is weakly concentrated in the ⁇ 011> orientation, and the magnetic properties at 45° from the steel plate rolling direction, which is a characteristic of ⁇ fibers, are It turns out that the value is not high enough.
• Japanese Patent Publication No. 2017-145462 Japanese Patent Application Publication No. 2017-193731 Japanese Patent Application Publication No. 2019-178380 Japanese Patent No. 4218077 Japanese Patent No. 5256916 Japanese Patent Application Publication No. 2011-111658 Japanese Patent Application Publication No. 2019-183185
• the present inventors conducted extensive studies to solve the above problems. The results revealed that it is important to optimize the chemical composition, grain size after hot rolling, and rolling reduction during cold rolling. Specifically, based on the assumption that the chemical composition is an ⁇ - ⁇ transformation system, the grain size is optimized by cooling under predetermined conditions after hot rolling, and then cold rolling is performed at a predetermined reduction rate, and the intermediate annealing temperature is adjusted. By controlling it within a predetermined range and performing a second cold rolling at an appropriate rolling reduction rate, annealing is performed to facilitate the development of ⁇ 411 ⁇ ⁇ 011> orientation crystal grains, which are normally difficult to develop. This is very important. As a result of further intensive studies based on such knowledge, the present inventors have come up with the following aspects of the invention.
• the Al content (mass%) was determined by [sol. Al], when the P content (mass%) is [P], the following formula (1) is satisfied,
• the remainder has a chemical composition consisting of Fe and impurities, Ahkl-uvw is the area ratio of crystal grains in the ⁇ hkl ⁇ uvw> orientation (within a margin of 10°) to the entire field of view when the steel plate surface is measured using a scanning electron microscope with electron beam backscatter diffraction (SEM-EBSD).
• A411-011 is 15% or more, Number density of precipitates is 0.5 pieces/ ⁇ m 2 to 50 pieces/ ⁇ m 2
• a non-oriented electrical steel sheet characterized by: (2 ⁇ [Mn]+2.5 ⁇ [Ni]+[Cu])-([Si]+2 ⁇ [sol.Al]+4 ⁇ [P]) ⁇ 1.5%...(1)
• % which is the unit of content of each element contained in a non-oriented electrical steel sheet or steel material, means “% by mass” unless otherwise specified.
• a numerical range expressed using " ⁇ ” means a range that includes the numerical values written before and after " ⁇ " as lower and upper limits.
• the non-oriented electrical steel sheet, cold-rolled steel sheet and steel material according to the present embodiment have a chemical composition in which ferrite-austenite transformation (hereinafter referred to as ⁇ - ⁇ transformation) can occur, C: 0.010% or less, Si: 1.50% to 4.00%, sol.
• ⁇ - ⁇ transformation ferrite-austenite transformation
• Al 0.0001% to 1.0000%, S: 0.010% or less, N: 0.0005% to 0.0100%, Ti: 0.0010% to 0.0050%, from Mn, Ni, Cu
• Mn 0.0001% to 1.0000%
• Sn 0.000% to 0.400%
• Sb 0.000 % to 0.400%
• P 0.000% to 0.400%
• the content of Al and P satisfies the predetermined conditions described below.
• impurities include those contained in raw materials such as ore and scrap, and those contained in manufacturing processes.
• C (C: 0.010% or less) C precipitates fine carbides and inhibits grain growth, thereby increasing iron loss and causing magnetic aging. Therefore, the lower the C content, the better. Such a phenomenon is remarkable when the C content exceeds 0.010%. Therefore, the C content is set to 0.010% or less.
• the lower limit of the C content is not particularly limited, but it is preferably 0.0005% or more, taking into account the cost of decarburization during refining.
• Si 1.50% to 4.00% Si increases electrical resistance, reduces eddy current loss, reduces iron loss, and increases the yield ratio to improve punching workability into iron cores. If the Si content is less than 1.50%, these effects cannot be fully obtained. Therefore, the Si content is set to 1.50% or more. On the other hand, if the Si content exceeds 4.00%, the magnetic flux density decreases, punching workability decreases due to an excessive increase in hardness, and cold rolling becomes difficult. Therefore, the Si content is set to 4.00% or less.
• sol.Al 0.0001% to 1.0000%
• Al increases electrical resistance, reduces eddy current loss, and reduces iron loss.
• sol. Al also contributes to increasing the relative magnitude of the magnetic flux density B50 to the saturation magnetic flux density.
• the magnetic flux density B50 is the magnetic flux density in a magnetic field of 5000 A/m. sol.
• sol. Al also has the effect of promoting desulfurization in steelmaking. Therefore, sol. Al content shall be 0.0001% or more.
• sol. When the Al content exceeds 1.0000% the magnetic flux density decreases, the yield ratio decreases, and the punching workability decreases. Therefore, sol. Al content shall be 1.0000% or less.
• sol. When the Al content is in the range of 0.0100% to 0.1000%, AlN precipitates and inhibits grain growth, resulting in a large amount of iron loss deterioration, so it is preferable to avoid this concentration range.
• S is not an essential element and is contained, for example, as an impurity in steel. S inhibits recrystallization and crystal grain growth during annealing due to fine MnS precipitation. Therefore, the lower the S content, the better. The increase in core loss and decrease in magnetic flux density due to inhibition of recrystallization and grain growth are significant when the S content exceeds 0.010%. Therefore, the S content is set to 0.010% or less. Note that the lower limit of the S content is not particularly limited, but it is preferably 0.0003% or more, taking into consideration the cost of desulfurization treatment during refining.
• N 0.0005% to 0.0100% Since N deteriorates magnetic properties through the formation of fine precipitates such as TiN and AlN, the N content is set to 0.0100% or less. Note that if TiN, which is a precipitate, is insufficient, the strength will be insufficient, so the N content is set to 0.0005% or more. Preferably the N content is 0.0010% or more.
• Ti is an element necessary for solid solution strengthening and grain refinement strengthening. If the Ti content is less than 0.0010%, these effects cannot be sufficiently obtained. Moreover, when the Ti content exceeds 0.0050%, a large amount of TiN, which is a fine precipitate, is formed, which deteriorates the magnetic properties. Therefore, the Ti content is set to 0.0010% to 0.0050%. Preferably, the Ti content is 0.0010% to 0.0030%.
• Mn content (mass%) is [Mn]
• Ni content (mass%) is [Ni]
• Cu content (mass%) is [Cu]
• Si content (mass%) is [Si]
• sol. The Al content (mass%) was determined by [sol. Al]
• P content (mass %) is [P]
• the following formula (1) is satisfied in mass %. (2 ⁇ [Mn]+2.5 ⁇ [Ni]+[Cu])-([Si]+2 ⁇ [sol.Al]+4 ⁇ [P]) ⁇ 1.5%...(1) If the above-mentioned formula (1) is not satisfied, the ⁇ - ⁇ transformation does not occur and the magnetic flux density becomes low.
• Co 0.000% to 1.000% Since Co is an effective element for causing ⁇ - ⁇ transformation, it may be included if necessary, but if it is included in excess, the cost may increase and the magnetic flux density may decrease. Therefore, the Co content is set to 1.000% or less.
• Sn and Sb improve the texture after cold rolling and recrystallization, and improve the magnetic flux density. Therefore, although these elements may be contained as necessary, if they are contained in excess, the steel becomes brittle. Therefore, the Sn content and the Sb content are both 0.400% or less.
• one or more types selected from the group consisting of 0.020% to 0.400% Sn and 0.020% to 0.400% Sb It is preferable to contain.
• P 0.000% to 0.400%
• the P content is set to 0.400% or less.
• the area ratio of grains with specific orientation was measured using a scanning electron microscope (SEM) equipped with electron back scattering diffraction (EBSD), which was observed under the following measurement conditions using OMI Analysis 7.3 (manufactured by TSL).
• SEM scanning electron microscope
• EBSD electron back scattering diffraction
• a target specific direction is extracted from the measurement area using a microscope (tolerance is set at 10°, hereinafter referred to as tolerance within 10°).
• the extracted area is divided by the area of the measurement area to determine the percentage. This percentage is defined as the area ratio of grains with specific orientation.
• the ⁇ 411 ⁇ 011> ratio is 15% or more when the surface of the steel sheet is measured by SEM-EBSD. If the ⁇ 411 ⁇ 011> ratio is less than 15%, excellent magnetic properties cannot be obtained. Therefore, the ⁇ 411 ⁇ 011> ratio is set to 15% or more, preferably 25% or more.
• ⁇ Measuring device SEM model number “JSM-6400 (manufactured by JEOL)” and EBSD detector model number “HIKARI (manufactured by TSL)”
• Step interval 0.3 ⁇ m (after intermediate annealing, after skin pass rolling), or 5.0 ⁇ m (after final annealing)
• Magneticnification 1000x (after intermediate annealing, after skin pass rolling), or 100x (after final annealing)
• ⁇ Measurement target Center layer (1/2 part of the plate thickness) of the Z plane (cutting surface of the steel plate in the thickness direction) at the center of the steel plate in the C direction
• ⁇ Measurement area Area of 1000 ⁇ m or more in the L direction and 1000 ⁇ m or more in the C direction
• the ⁇ 411 ⁇ 011> orientation has superior magnetic properties in the 45° direction compared to ⁇ 411 ⁇ 148> and the like.
• This is synonymous with having the maximum intensity near the ⁇ 411 ⁇ 011> direction.
• the area ratio of crystal grains having a specific orientation (tolerance within 10°) with respect to the entire field of view when measured by SEM-EBSD is expressed as follows.
• the area ratio of the crystal grains with the crystal orientation of the ⁇ hkl ⁇ uvw> orientation (within a tolerance of 10°) to the entire field of view is Ahkl-uvw
• the area ratio of the crystal grains with the crystal orientation of the ⁇ hkl ⁇ orientation (within a tolerance of 10°) is Ahkl-uvw.
• the magnetic properties are superior when there are many crystal grains with a crystal orientation of ⁇ 411 ⁇ direction, but inferior when there are many crystal grains with a crystal orientation of ⁇ 111 ⁇ direction. Therefore, it is preferable that the ⁇ 411 ⁇ ratio exceeds the ⁇ 111 ⁇ ratio, and more preferably, the ⁇ 411 ⁇ ratio is at least twice the ⁇ 111 ⁇ ratio.
• the precipitates are mainly fine precipitates such as TiN, and also include fine precipitates such as AlN and MnS. If the number density of these precipitates is less than 0.5 pieces/ ⁇ m 2 , the strength will be insufficient. On the other hand, if the number of precipitates increases and the number density of precipitates is greater than 50 pieces/ ⁇ m 2 , the TiN precipitates become excessive and the magnetic properties deteriorate. Therefore, the number density of precipitates in a non-oriented electrical steel sheet is set to 0.5/ ⁇ m 2 to 50/ ⁇ m 2 .
• the number density of precipitates is measured, for example, by observing a sample using an extraction replica method using a transmission electron microscope (TEM) and calculating the number density. Specifically, a transmission electron microscope was used to observe the surface of the steel plate at a depth of 1/2 relative to the plate thickness t using the extraction replica method, and the precipitates in a field of view of 5 ⁇ m x 5 ⁇ m were observed in the same sample. Measure the number of pieces. However, during observation, make sure that the field of view does not include coarse precipitates (equivalent circle diameter of 1 ⁇ m or more) that are not included in the calculation of the number density. Then, the number of precipitates is measured in 10 or more fields of view in the same sample, and the average value is calculated as the number density of precipitates. Note that image analysis software may be used when measuring the number of precipitates.
• TEM transmission electron microscope
• the thickness of the non-oriented electrical steel sheet according to this embodiment is not particularly limited.
• the preferred thickness of the non-oriented electrical steel sheet according to this embodiment is 0.25 to 0.50 mm. Normally, the thinner the plate, the lower the iron loss, but the lower the magnetic flux density. Considering this point, if the plate thickness is 0.25 mm or more, the iron loss will be lower and the magnetic flux density will be higher. Further, if the plate thickness is 0.50 mm or less, low iron loss can be maintained. A more preferable lower limit of the plate thickness is 0.30 mm.
• the non-oriented electrical steel sheet according to the present embodiment has excellent magnetic properties such as a magnetic flux density B50 of 1.70T or more at 45° to the rolling direction, and an iron loss W10 at 45° to the rolling direction.
• /400 is preferably 14 W/kg or less.
• the tensile strength is 600 MPa or more.
• the tensile strength is determined by taking a JIS No. 5 test piece of a non-oriented electrical steel sheet whose longitudinal direction is the rolling direction, and conducting a tensile test in accordance with JIS Z2241:2011.
• the above-mentioned non-oriented electrical steel sheet is a characteristic of a non-oriented electrical steel sheet manufactured by performing finish annealing.
• the characteristics of the non-oriented electrical steel sheet before finishing annealing (after skin pass rolling) will be explained.
• the non-oriented electrical steel sheet after skin pass rolling (before finish annealing) has the following GOS (Grain Orientation Spread) value (Gs).
• GOS Gram Orientation Spread
• the GOS value is the average of the orientation differences between all measurement points (pixels) within the same grain, and the GOS value becomes higher in crystal grains with a large amount of strain.
• the upper limit of the GOS value Gs after skin pass rolling is set to 3.0.
• the GOS value Gs is less than 0.8, the amount of strain becomes too small and the final annealing time required for grain growth due to bulging becomes long. Therefore, the GOS value Gs after skin pass rolling is 0.8 or more and 3.0 or less.
• the ⁇ fiber has the ⁇ hkl ⁇ 011> orientation.
• OMI Analysis 7.3 to extract the ⁇ hkl ⁇ 011> direction (within a margin of 10°). The extracted area is divided by the area of the measurement area to determine the percentage. This percentage is defined as the ⁇ fiber rate.
• the ⁇ fiber ratio is 20% or more, preferably 25% or more.
• the ODF strength in the ⁇ 100 ⁇ 011> direction is set to 15 or less.
• the ⁇ 411 ⁇ 011> orientation has excellent magnetic properties and is less sensitive to stress than the ⁇ 100 ⁇ 011> orientation, so magnetic deterioration in crimped cores and the like is less likely.
• the non-oriented electrical steel sheet according to the present embodiment can be widely applied to applications that require magnetic properties (high magnetic flux density and low iron loss), but it can also be used in applications that require particularly high strength, such as rotors. Can be applied to desired applications.
• hot rolling, cold rolling, intermediate annealing, second light reduction cold rolling (hereinafter referred to as skin pass rolling), and final annealing are performed.
• hot rolling is performed on a steel material that satisfies the above-mentioned chemical composition to produce a hot rolled plate.
• the hot rolling process includes a heating process and a rolling process.
• the steel material is, for example, a slab manufactured by normal continuous casting, and the steel material having the above-mentioned composition is manufactured by a well-known method.
• molten steel is produced in a converter or electric furnace.
• the produced molten steel is subjected to secondary refining using a degassing facility or the like to obtain molten steel having the above chemical composition.
• Slabs are cast using molten steel by continuous casting or ingot forming.
• the cast slab may be subjected to blooming rolling.
• the heating step it is preferable to heat the steel material having the above chemical composition to 1100 to 1200°C.
• the steel material is charged into a heating furnace or a soaking furnace and heated in the furnace.
• the holding time at the heating temperature in the heating furnace or soaking furnace is not particularly limited, but is, for example, 30 to 200 hours.
• the steel material heated in the heating process is rolled in multiple passes to produce a hot rolled plate.
• "pass" means that the steel plate passes through one rolling stand having a pair of work rolls and is rolled down.
• Hot rolling is performed, for example, by performing tandem rolling using a tandem rolling mill that includes a plurality of rolling stands arranged in a row (each rolling stand has a pair of work rolls) to perform rolling in multiple passes.
• reverse rolling with a pair of work rolls may be performed to perform multiple passes of rolling. From the viewpoint of productivity, it is preferable to perform multiple rolling passes using a tandem rolling mill.
• the rolling process consists of rough rolling in the first stage and finish rolling in the second stage, and in this embodiment, the reduction ratio in the final pass of finish rolling is set to 20% or more.
• the reduction ratio in the final pass of finish rolling is set to 20% or more, preferably 30% or more, and more preferably 35% or more.
• the rolling in the rolling process is performed at a temperature in the ⁇ region or the ⁇ + ⁇ two-phase region (Ar1 point or higher). That is, hot rolling is performed so that the temperature (finish rolling temperature FT (°C)) when passing through the final pass of the finish rolling is Ar1 point or higher. It is also preferable to perform hot rolling so that the finish rolling temperature FT is Ac3 point or lower. By performing hot rolling so that the finish rolling temperature FT is Ac3 point or lower, strain can be preferably introduced into the crystal grains in combination with cooling, etc., which will be described later, and as a result, A411-011 can be increased.
• the finish rolling temperature FT is higher than Ac3 point, strain cannot be preferably introduced into the crystal grains, and as a result, the desired A411-011 may not be obtained.
• the Ar1 point can be determined from the thermal expansion change of the steel sheet during cooling at an average cooling rate of 1° C./s.
• the Ac3 point and the Ac1 point described below can be determined from the thermal expansion change of the steel sheet during heating at an average heating rate of 1° C./s.
• the finish rolling temperature FT means the surface temperature (° C.) of the steel sheet at the exit side of the rolling stand where the final pass of rolling is performed in the above-mentioned rolling process during the hot rolling process.
• the finish rolling temperature FT can be measured, for example, by a thermometer installed on the exit side of the rolling stand that performs the final pass rolling.
• the finish rolling temperature FT is, for example, the average value of the temperature measurement results of the portion excluding one section at the tip and one section at the rear end when the entire length of the steel plate is divided into 10 sections in the rolling direction. means.
• the texture of the hot rolled sheet becomes a structure in which unrecrystallized austenite is transformed when immediately quenched, and a structure in which partially recrystallized austenite is transformed when immediately quenched is omitted. If quenching is performed immediately after finish rolling, it will accumulate in the ⁇ 100 ⁇ 011> orientation in the structure after finish annealing, and if quenching is omitted immediately after finish rolling, it will accumulate in the structure after finish annealing. 411 ⁇ 011> direction. Therefore, it is considered important to transform partially recrystallized austenite in order to strengthen the ⁇ 411 ⁇ 011> orientation.
• the cooling conditions are preferably such that the average crystal grain size in the hot rolled sheet before cold rolling is 3 to 10 ⁇ m. If the crystal grains become too coarse, it becomes difficult to develop ⁇ fibers after cold rolling and intermediate annealing, and the desired ⁇ 411 ⁇ 011> ratio may not be obtained. Furthermore, if the grain size is too fine, the desired ⁇ 411 ⁇ 011> ratio cannot be obtained. Therefore, in order to make the average grain size of the hot rolled sheet before cold rolling 3 to 10 ⁇ m, the temperature should be brought to below Ar1 point within 3 seconds after passing through the final pass of finish rolling. The particle size is measured, for example, by a cutting method.
• the surface temperature of the hot rolled sheet 3 seconds after passing through the final pass of finish rolling is measured by the following method.
• a cooling device and a conveyance line are arranged downstream of a hot rolling machine.
• a thermometer for measuring the surface temperature of the hot rolled plate is disposed on the exit side of the rolling stand that performs the final pass of the hot rolling mill.
• a plurality of thermometers are arranged along the conveyance line on the conveyance roller disposed downstream of the rolling stand.
• the cooling device is located downstream of the rolling stand that performs the final pass.
• a temperature meter is placed on the inlet side of the water cooling device.
• the cooling device may be, for example, a well-known water cooling device or a well-known forced air cooling device.
• the cooling device is a water cooling device.
• the cooling liquid of the water cooling device may be water or a mixed fluid of water and air.
• the hot rolled plate temperature is measured with a thermometer placed in the hot rolling equipment line. Then, the temperature is determined 3 seconds after passing through the final pass of finish rolling.
• hot rolled plate is wound up without annealing, and the hot rolled plate is cold rolled.
• hot rolled sheet annealing means, for example, heat treatment at a heating temperature of 1 point Ac or less and a temperature of 300° C. or higher.
• Cold rolling is performed on the hot rolled plate without performing hot rolled plate annealing on the hot rolled plate.
• Cold rolling is performed, for example, by performing tandem rolling using a tandem rolling mill that includes a plurality of rolling stands arranged in a row (each rolling stand has a pair of work rolls) to perform rolling in multiple passes.
• tandem rolling mill that includes a plurality of rolling stands arranged in a row (each rolling stand has a pair of work rolls) to perform rolling in multiple passes.
• reverse rolling may be performed using a Sendzimir rolling mill or the like having a pair of work rolls to perform rolling in one pass or multiple passes. From the viewpoint of productivity, it is preferable to perform rolling in multiple passes using a tandem rolling mill.
• cold rolling is performed without performing annealing treatment during cold rolling.
• cold rolling is performed in multiple passes without annealing treatment between the cold rolling passes.
• cold rolling may be performed in only one pass using a reverse rolling mill.
• cold rolling is performed using a tandem rolling mill, cold rolling is performed continuously in multiple passes (passes at each rolling stand).
• the rolling reduction ratio RR1 (%) in cold rolling is 75 to 95%.
• intermediate annealing is performed.
• the intermediate annealing temperature T1 (°C) is the plate temperature (temperature of the steel plate surface) near the extraction port of the annealing furnace.
• the plate temperature of the annealing furnace can be measured with a thermometer placed at the annealing furnace outlet.
• the holding time at the intermediate annealing temperature T1 in the intermediate annealing step may be a time well known to those skilled in the art.
• the holding time at the intermediate annealing temperature T1 is, for example, 5 to 60 seconds, but the holding time at the intermediate annealing temperature T1 is not limited to this.
• the rate of temperature increase up to the intermediate annealing temperature T1 may also be under known conditions.
• the temperature increase rate up to the intermediate annealing temperature T1 is, for example, 10.0 to 20.0° C./sec, but the temperature increase rate up to the intermediate annealing temperature T1 is not limited to this.
• the atmosphere during intermediate annealing is not particularly limited, for example, an atmospheric gas (dry) containing 20% H 2 and the balance consisting of N 2 is used as the atmosphere during intermediate annealing.
• the cooling rate of the steel plate after intermediate annealing is not particularly limited, and the cooling rate is, for example, 5.0 to 60.0°C/sec.
• the resulting cold rolled steel sheet has an ⁇ fiber ratio (within tolerance of 10°) of 15% or more when measured by SEM-EBSD.
• the composition of the ⁇ - ⁇ transformation system high concentration of ⁇ -former elements such as Mn, Ni, and Cu
• high Mn, etc. the conditions from hot rolling to intermediate annealing must be as described above, and the cooling conditions after finish rolling are particularly important.
• ⁇ fibers that tend to generate ⁇ 411 ⁇ 011> orientation are transformed from partially recrystallized austenite to ferrite, and cold-rolled a hot-rolled sheet with an average grain size of 3 to 10 ⁇ m after hot rolling. It is then developed by intermediate annealing. As described above, immediately after quenching, unrecrystallized austenite becomes a transformed structure, and partially recrystallized austenite does not become a transformed structure.
• the non-oriented electrical steel sheet of the present invention is obtained by subjecting the cold rolled steel sheet manufactured in this manner to skin pass rolling and further final annealing under the conditions described below.
• the skin pass rolling is performed next. Specifically, the cold rolled steel plate after the intermediate annealing process is rolled (cold rolled) at room temperature in the atmosphere.
• the skin pass rolling here uses, for example, a reverse rolling mill typified by the above-mentioned Sendzimir rolling mill or a tandem rolling mill.
• skin pass rolling rolling is performed without performing annealing treatment in the middle. For example, when reverse rolling is performed and skin pass rolling is performed in multiple passes, the rolling is performed multiple times without intervening annealing treatment between passes. Note that skin pass rolling may be performed in only one pass using a reverse rolling mill. Further, when performing skin pass rolling using a tandem rolling mill, rolling is performed continuously in multiple passes (passes in each rolling stand).
• the strain introduced into the steel plate is once reduced by intermediate annealing. Then, skin pass rolling is performed. As a result, the excessive strain introduced by cold rolling is reduced in intermediate annealing, and by performing intermediate annealing, preferential recrystallization of ⁇ 111 ⁇ grains in the surface of the steel sheet is suppressed. Thus, ⁇ 411 ⁇ 011> crystal orientation grains remain. Then, in the skin pass rolling, an appropriate amount of strain is introduced into each grain in the steel sheet, so that grain growth due to bulging is likely to occur in the next step of final annealing.
• the reduction ratio RR2 in the skin pass rolling is set to 5 to 20%.
• the rolling reduction ratio RR2 is set to 5 to 20%.
• the number of passes in skin pass rolling may be one pass (that is, only one rolling) or multiple passes.
• the above-mentioned GOS value and ⁇ -fiber ratio can be obtained by recrystallizing a steel sheet with an ⁇ - ⁇ transformation system composition (high Mn, etc.) by intermediate annealing and performing skin pass rolling under the above conditions. It will be done.
• finish annealing is performed at 750° C. or higher and Ac 1 point or lower for 2 hours or more.
• T2 (°C) is less than 750°C, grain growth due to bulging does not occur sufficiently. In this case, the degree of integration in the ⁇ 411 ⁇ 011> direction will decrease. Furthermore, if the final annealing temperature T2 exceeds the Ac1 point, part of the structure of the steel sheet transforms into austenite, grain growth due to bulging does not occur, and the desired ⁇ 411 ⁇ 011> ratio cannot be obtained.
• the annealing time is less than 2 hours, grain growth due to bulging will not occur sufficiently even if the final annealing temperature T2 is 750°C or more and Ac1 point or less, and the degree of integration of the ⁇ 411 ⁇ 011> orientation will decrease. It will drop.
• the upper limit of the annealing time for final annealing is not particularly limited, but the effect is saturated even if the annealing time exceeds 10 hours, so the preferable upper limit is 10 hours.
• the final annealing temperature T2 is the plate temperature (temperature of the steel plate surface) near the extraction port of the annealing furnace.
• the furnace temperature of the annealing furnace can be measured with a thermometer placed at the annealing furnace outlet.
• the heating rate TR2 up to the final annealing temperature T2 in the final annealing process may be any heating rate known to those skilled in the art, and the holding time ⁇ t2 (seconds) at the final annealing temperature T2 may be any time known to those skilled in the art.
• the holding time ⁇ t2 refers to the holding time after the surface temperature of the steel sheet reaches the final annealing temperature T2.
• the preferred heating rate TR2 to the finishing annealing temperature T2 in the finishing annealing process is 0.1°C/sec or more and less than 10.0°C/sec. If the heating rate TR2 is 0.1°C/sec or more and less than 10.0°C/sec, grain growth due to bulging occurs sufficiently. In this case, the concentration of the ⁇ 411 ⁇ 011> crystal orientation increases, and the crystal grains on the ND surface at the center of the plate thickness become even less likely to vary.
• the temperature increase rate TR2 is determined by the following method.
• a thermocouple is attached to a steel plate having the above chemical composition and obtained by carrying out the above hot rolling to skin pass to obtain a sample steel plate.
• a sample steel plate with a thermocouple attached is heated, and the time from the start of temperature rise until reaching the final annealing temperature T2 is measured.
• the temperature increase rate TR2 is determined based on the measured time.
• the holding time ⁇ t2 at the final annealing temperature T2 in the final annealing step is 2 hours or more. If the holding time ⁇ t2 is 2 hours or more, grain growth of ⁇ 411 ⁇ 110> grains occurs due to bulging, and the strength is increased by grain refinement and reinforcement. In this case, the degree of integration of the ⁇ 411 ⁇ 011> crystal orientation is further increased, and the crystal grains on the ND plane at the center of the plate thickness are also less likely to vary.
• the lower limit of the holding time ⁇ t2 is 2 hours, preferably 3 hours. As mentioned above, the upper limit of the retention time ⁇ t2 is preferably 10 hours, more preferably 5 hours.
• the atmosphere during the final annealing step is not particularly limited.
• an atmospheric gas (dry) containing, for example, 20% H 2 and the remainder N 2 is used.
• the cooling rate of the steel plate after final annealing is not particularly limited. The cooling rate is, for example, 5 to 20°C/sec.
• the non-oriented electrical steel sheet after skin pass rolling may be shipped without performing finish annealing.
• the process up to skin pass rolling is performed at a steel sheet manufacturing company, the non-oriented electrical steel sheet is punched or laminated at the core manufacturing company to which it is shipped, and then annealing is performed at a temperature of 750°C or higher and Ac1 point or lower for 2 hours or more.
• strain relief annealing may be performed instead of finish annealing.
• the non-oriented electrical steel sheet according to this embodiment can be manufactured.
• the method for manufacturing a non-oriented electrical steel sheet according to the present embodiment is not limited to the above manufacturing process.
• shot blasting and/or pickling may be performed after hot rolling and before cold rolling.
• shot blasting shot blasting is performed on a hot rolled steel plate to destroy and remove scale formed on the surface of the hot rolled steel plate.
• pickling treatment for example, an aqueous hydrochloric acid solution is used as a pickling bath. Pickling removes scale formed on the surface of the steel plate.
• shot blasting may be performed, and then pickling may be performed.
• pickling may be performed without shot blasting.
• Shot blasting may be performed after hot rolling and before cold rolling, and pickling treatment may not be performed. Note that shot blasting and pickling are optional steps. Therefore, it is not necessary to carry out both the shot blasting process and the pickling process after hot rolling and before cold rolling.
• the method for manufacturing an electrical steel sheet according to this embodiment may further include coating after the final annealing.
• an insulating film is formed on the surface of the steel sheet after the final annealing.
• the type of insulation coating is not particularly limited.
• the insulating coating may have an organic component or an inorganic component, and the insulating coating may contain an organic component and an inorganic component.
• inorganic components include dichromic acid-boric acid, phosphoric acid, and silica.
• organic component include common acrylic, acrylic styrene, acrylic silicone, silicone, polyester, epoxy, and fluorine resins.
• the preferred resin is an emulsion type resin.
• An insulating coating that exhibits adhesive properties by applying heat and/or pressure may also be applied. Insulating coatings with adhesive properties include, for example, acrylic, phenolic, epoxy, and melamine resins.
• coating is an optional step. Therefore, it is not necessary to perform coating after final annealing.
• the non-oriented electrical steel sheet according to this embodiment is not limited to the above-described manufacturing method.
• the surface of the steel plate is measured by electron beam backscatter diffraction (EBSD)
• the area ratio of crystal grains having the ⁇ 411 ⁇ 011> orientation (tolerance within 10°) to the entire field of view is 15% or more, and there is no precipitation.
• the manufacturing method is not limited to the above.
• non-oriented electrical steel sheet according to an embodiment of the present invention will be specifically described with reference to Examples.
• the examples shown below are merely examples of non-oriented electrical steel sheets according to embodiments of the present invention, and the non-oriented electrical steel sheets according to the present invention are not limited to the following examples.
• Ingots having the components shown in Table 1 below were produced by casting molten steel.
• the left side of the equation represents the value on the left side of the above-mentioned equation (1).
• the produced ingots were heated and hot rolled to the slab heating temperature ST shown in Table 1, and finish rolled at the finish rolling temperature FT shown in Table 1.
• cooling was performed under the cooling conditions shown in Table 1 (time from passing the final pass to starting cooling, and temperature of the steel plate 3 seconds after passing the final pass). went.
• the hot-rolled steel plates were not subjected to hot-rolled plate annealing, scale was removed by pickling, and cold rolling was performed at the rolling reduction ratio RR1 shown in Table 1. Then, intermediate annealing was performed in an atmosphere of 20% hydrogen and 80% nitrogen, and intermediate annealing was performed for 30 seconds while controlling the intermediate annealing temperature T1 to the temperature shown in Table 1.
• the comparative example No. In No. 2 the ⁇ 411 ⁇ 011> ratio was small because it was rapidly cooled after finish rolling, and the iron loss deterioration rate under compressive stress was large. Further, since Ti was not contained, precipitates mainly composed of TiN were not generated, and as a result, the precipitates were insufficient overall, resulting in insufficient tensile strength. Comparative example No. No. 3 had a composition that lacked the total of one or more selected from the group consisting of Mn, Ni, and Cu and did not cause ⁇ - ⁇ transformation, so the ⁇ 411 ⁇ 011> ratio was small and the magnetic flux density B50 (45° direction), was inferior in iron loss W10/400 and iron loss deterioration rate. Comparative example No.
• Comparative example No. No. 9 had a large iron loss W10/400 due to a lack of Si. Furthermore, since Ti was not contained, precipitates mainly composed of TiN were not generated, and as a result, the precipitates were insufficient overall, resulting in insufficient tensile strength. Comparative example No. In No. 10, the total amount of one or more selected from the group consisting of Mn, Ni, and Cu was excessive, so the magnetic flux density B50 was poor both in the 45° direction and on the average around the entire circumference. In addition, due to segregation, two-piece cracking occurred in some parts during cold rolling. Comparative example No. No.

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