WO2024150732A1 - Non-oriented electromagnetic steel sheet - Google Patents

Non-oriented electromagnetic steel sheet Download PDF

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Publication number
WO2024150732A1
WO2024150732A1 PCT/JP2024/000133 JP2024000133W WO2024150732A1 WO 2024150732 A1 WO2024150732 A1 WO 2024150732A1 JP 2024000133 W JP2024000133 W JP 2024000133W WO 2024150732 A1 WO2024150732 A1 WO 2024150732A1
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steel sheet
grains
rolling
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PCT/JP2024/000133
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French (fr)
Japanese (ja)
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夏子 杉浦
一郎 田中
鉄州 村川
俊 太田
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日本製鉄株式会社
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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
    • 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
    • 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
    • C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties

Definitions

  • This disclosure relates to non-oriented electrical steel sheets.
  • Non-oriented electrical steel sheets are used, for example, in the iron cores of motors, and are required to have excellent magnetic properties in the direction parallel to the plate surface, such as low core loss and high magnetic flux density.
  • strain-induced grain growth can suppress the accumulation of the ⁇ 111 ⁇ orientation, which does not have an easy axis of magnetization in the in-plane direction of the sheet, and is therefore effectively used in non-oriented electrical steel sheets.
  • the Goss orientation has better magnetic properties in one direction than the ⁇ 111 ⁇ orientation, but the magnetic properties are hardly improved on average around the circumference. Therefore, conventional methods have the problem of not being able to obtain excellent magnetic properties on average around the circumference.
  • patent documents 11 to 13 disclose technologies for developing ⁇ 100 ⁇ crystal orientation or ⁇ 411 ⁇ crystallization in a component system in which ⁇ phase transformation occurs.
  • a fine-grained ⁇ phase structure is achieved at the time of hot rolling by using a steel composition with a low ⁇ phase transformation temperature and transforming at a low temperature, and the addition of ⁇ -stabilizing elements such as Mn, Cu, and Ni is utilized from the viewpoint of lowering the transformation temperature and delaying recovery recrystallization to promote the accumulation of strain.
  • Mn is known as a segregation element, and if the amount added is increased, it segregates in the center of the thickness of the hot-rolled sheet, causing cracks when the hot-rolled sheet is cold-rolled.
  • the present disclosure aims to provide a non-oriented electrical steel sheet with a chemical composition in which Mn is suppressed and the contents of elements such as Cu and Ni are optimized so that rolling properties are not an issue, and which has small in-plane anisotropy and excellent magnetic properties averaged all around (averaged in all directions).
  • the present inventors have investigated a technique for forming a favorable texture for non-oriented electrical steel sheets by utilizing strain-induced grain growth. In the process, they have focused on the fact that ⁇ 411 ⁇ uvw> orientation (hereinafter, ⁇ 411 ⁇ orientation) crystal grains are as resistant to strain as ⁇ 100 ⁇ uvw> orientation (hereinafter, ⁇ 100 ⁇ orientation).
  • strain-induced grain growth causes the ⁇ 411 ⁇ orientation crystal grains to encroach on the ⁇ 111 ⁇ orientation crystal grains while simultaneously suppressing the development of ⁇ 100 ⁇ orientation crystal grains, thereby producing a non-oriented electrical steel sheet with the ⁇ 411 ⁇ orientation as the main orientation.
  • the magnetic properties are improved on an average around the circumference (average of the rolling direction, width direction, direction at 45 degrees to the rolling direction, and direction at 135 degrees to the rolling direction).
  • the inventors also investigated a method for increasing the number of ⁇ 411 ⁇ oriented crystal grains relative to ⁇ 100 ⁇ oriented crystal grains at a stage before strain-induced grain growth occurs. As a result, they discovered a method in which hot rolling is performed under specific conditions for steel types with low contents of Mn, Ni, Cu, etc., and then cold rolling and annealing are performed, followed by re-cold rolling (skin pass rolling) at a lower reduction ratio, followed by final annealing.
  • a non-oriented electrical steel sheet In mass percent, C: 0.0100% or less, Si: 1.50% to 4.00%, sol. Al: 0.0001% to 1.0%, S: 0.0100% or less, N: 0.0100% or less, Mn: 0.10% or more, One or more selected from Mn, Ni, and Cu: less than 2.50% in total; Mo: 0.0% to less than 2.5% Cr: 0.0% to less than 2.5% Ti: 0.000% to 0.005%, Nb: 0.000% to 0.005%, Sn: 0.000% to 0.400%, Sb: 0.000% to 0.400%, P: 0.000% to 0.400%, and one or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total; In mass%, the C content is [C], the Mo content is [Mo], the Cr content is [Cr], the Mn content is [Mn], the Ni content
  • the alloy has a chemical composition in which the transformation temperature Ar 3 (°C) defined by the following formula (1) is 750 to 1050°C, with the balance being Fe and impurities, where the sol. Al content is [sol. Al] and the P content is [P]: Furthermore, when observed by EBSD on a plane parallel to the steel sheet surface, the total area is S tot , the area of ⁇ 411 ⁇ oriented grains is S 411 , the area of ⁇ 100 ⁇ oriented grains is S 100 , the area of oriented grains having a Taylor factor M of more than 2.9 according to the following formula (2) is S tyl , the total area of oriented grains having the Taylor factor M of 2.9 or less is S tra , the average KAM value of the ⁇ 411 ⁇ oriented grains is K 411 , and the average KAM value of the oriented grains having the Taylor factor M of more than 2.9 is K tyl , and the following ( Formula (3) and formulas (4) to (7) are satisfied.
  • Ar 3 (°C) 1020-325 ⁇ [C]+33 ⁇ [Si]+287 ⁇ [P]+80 ⁇ [sol.
  • M (cos ⁇ cos ⁇ ) -1 ...(2)
  • ⁇ represents the angle between the stress vector and the slip direction vector of the crystal
  • ⁇ represents the angle between the stress vector and the normal vector of the slip plane of the crystal.
  • a non-oriented electrical steel sheet In mass percent, C: 0.0100% or less, Si: 1.50% to 4.00%, sol. Al: 0.0001% to 1.0%, S: 0.0100% or less, N: 0.0100% or less, Mn: 0.10% or more, One or more selected from Mn, Ni, Co, Pt, Pb, Au, and Cu: less than 2.50% in total; Mo: 0.0% to less than 2.5% Cr: 0.0% to less than 2.5% Ti: 0.000% to 0.005%, Nb: 0.000% to 0.005%, Sn: 0.000% to 0.400%, Sb: 0.000% to 0.400%, P: 0.000% to 0.400%, and one or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total, and when the C content is [C], the Mo content is [Mo], the Cr content is [Cr], the Mn content
  • Al content is [sol. Al]
  • P content is [P]
  • the transformation temperature Ar 3 (°C) defined by the following formula (1) is 750 to 1050°C
  • the balance is Fe and impurities
  • the total area is S tot
  • the area of the ⁇ 411 ⁇ oriented grains is S 411
  • the area of the ⁇ 100 ⁇ oriented grains is S 100
  • the area of the oriented grains having a Taylor factor M of more than 2.9 according to the following formula (2) is S tyl
  • the total area of the oriented grains having the Taylor factor M of 2.9 or less is S tra
  • the average KAM value of the ⁇ 411 ⁇ oriented grains is K 411
  • the average KAM value of the oriented grains having the Taylor factor M of more than 2.9 is K tyl
  • the following formulas (3) and (4) to (7) are satisfied.
  • Ar 3 (°C) 1020-325 ⁇ [C]+33 ⁇ [Si]+287 ⁇ [P]+80 ⁇ [sol.
  • Al]-120 ⁇ ([Mn]+[Mo]+[Cu])-46 ⁇ ([Cr]+[Ni])...(1) M (cos ⁇ cos ⁇ ) -1 ...(2) S 411 /S 100 >1.00...(3) 0.20 ⁇ S tyl /S tot ⁇ 0.85 (4) 0.05 ⁇ S 411 /S tot ⁇ 0.80 (5) S 411 /S tra ⁇ 0.50 (6) K 411 /K tyl ⁇ 0.990 (7)
  • ⁇ represents the angle between the stress vector and the slip direction vector of the crystal
  • ⁇ represents the angle between the stress vector and the normal vector of the slip plane of the crystal.
  • a non-oriented electrical steel sheet In mass percent, C: 0.0100% or less, Si: 1.50% to 4.00%, sol. Al: 0.0001% to 1.0%, S: 0.0100% or less, N: 0.0100% or less, Mn: 0.10% or more, One or more selected from Mn, Ni, and Cu: less than 2.50% in total; Mo: 0.0% to less than 2.5% Cr: 0.0% to less than 2.5% Ti: 0.000% to 0.005%, Nb: 0.000% to 0.005%, Sn: 0.000% to 0.400%, Sb: 0.000% to 0.400%, P: 0.000% to 0.400%, and One or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total;
  • the alloy has a chemical composition in which the transformation temperature Ar 3 (°C) defined by the following formula (1) is 750 to 1050°C, with the balance being Fe and
  • Al content is [sol. Al], and the P content is [P], in mass %, Furthermore, when observed by EBSD on a plane parallel to the steel sheet surface, the following formulas (8) to (11) are satisfied when the total area is S tot , the area of the ⁇ 411 ⁇ oriented grains is S 411 , the area of the ⁇ 100 ⁇ oriented grains is S 100 , the area of the oriented grains having a Taylor factor M of more than 2.9 according to the following formula (2) is S tyl , and the total area of the oriented grains having a Taylor factor M of 2.9 or less is S tra .
  • Ar 3 (°C) 1020-325 ⁇ [C]+33 ⁇ [Si]+287 ⁇ [P]+80 ⁇ [sol.
  • Al 0.0001% to 1.0%, S: 0.0100% or less, N: 0.0100% or less, Mn: 0.10% or more, One or more selected from Mn, Ni, Co, Pt, Pb, Au, and Cu: less than 2.50% in total; Mo: 0.0% to less than 2.5% Cr: 0.0% to less than 2.5% Ti: 0.000% to 0.005%, Nb: 0.000% to 0.005%, Sn: 0.000% to 0.400%, Sb: 0.000% to 0.400%, P: 0.000% to 0.400%, and one or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total;
  • the alloy has a chemical composition in which the transformation temperature Ar 3 (°C) defined by the following formula (1) is 750 to 1050°C, with the balance being Fe and impurities, where the C content is [C], the Mo content is [Mo], the Cr content is [ Cr], the M
  • Al content is [sol. Al], and the P content is [P], in mass %, Furthermore, when observed by EBSD on a plane parallel to the steel sheet surface, the following formulas (8) to (11) are satisfied when the total area is S tot , the area of the ⁇ 411 ⁇ oriented grains is S 411 , the area of the ⁇ 100 ⁇ oriented grains is S 100 , the area of the oriented grains having a Taylor factor M of more than 2.9 according to the following formula (2) is S tyl , and the total area of the oriented grains having a Taylor factor M of 2.9 or less is S tra .
  • Ar 3 (°C) 1020-325 ⁇ [C]+33 ⁇ [Si]+287 ⁇ [P]+80 ⁇ [sol.
  • non-oriented electrical steel sheet having a chemical composition in which the content of elements such as Cu and Ni is optimized while suppressing the addition of Mn so that rollability is not an issue, and which has small in-plane anisotropy and excellent magnetic properties averaged all around (averaged in all directions).
  • the non-oriented electrical steel sheet according to this embodiment is manufactured by subjecting a steel material having a chemical composition described below to a hot rolling process, a cold rolling process, an intermediate annealing process, and a skin pass rolling process. Furthermore, a non-oriented electrical steel sheet according to another embodiment of the present disclosure is manufactured by subjecting a steel material having a chemical composition described below to a cold rolling process, an intermediate annealing process, a skin pass rolling process, and a final annealing process.
  • the amount of Mn added is kept low to ensure rollability, and further, the components are adjusted, and then the hot rolling conditions are optimized to form an appropriate ⁇ -processed grain structure at the hot-rolled sheet stage, so that ⁇ 411 ⁇ oriented grains develop during the subsequent cold rolling and intermediate annealing.
  • the ⁇ 411 ⁇ oriented grains By making the number of ⁇ 411 ⁇ oriented grains greater than the ⁇ 100 ⁇ oriented grains at a stage before strain-induced grain growth occurs, the ⁇ 411 ⁇ oriented grains mainly encroach on the ⁇ 111 ⁇ oriented grains due to strain-induced grain growth, while at the same time suppressing the development of the ⁇ 100 ⁇ oriented grains, thereby producing a non-oriented electrical steel sheet with the ⁇ 411 ⁇ oriented grain as the main orientation.
  • the final annealing after skin pass rolling causes the steel sheet to undergo strain induced grain growth and/or normal grain growth.
  • sufficiently suppressing the development of the ⁇ 100 ⁇ orientation while enriching the ⁇ 411 ⁇ orientation grains is effective in reducing the in-plane anisotropy of the magnetic properties and improving the circumferential average (all-directional average).
  • the steel sheet after skin-pass rolling is the original sheet for the steel sheet after strain-induced grain growth and normal grain growth.
  • the steel sheet after skin-pass rolling and the steel sheet after strain-induced grain growth and normal grain growth will all be described as non-oriented electrical steel sheet.
  • the number of ⁇ 411 ⁇ orientation grains is further increased in the subsequent skin-pass rolling and final annealing, improving the magnetic properties all around.
  • the number of ⁇ 411 ⁇ orientation grains may be increased before skin-pass rolling in a process other than that described above.
  • non-oriented electrical steel sheet includes not only coil-shaped or cut-plate steel sheet, but also steel sheet processed into a specific shape as a material for products (components) such as motor cores, and further steel sheet laminated after processing to form motor cores.
  • the chemical composition of the non-oriented electrical steel sheet according to the embodiment of the present disclosure and the steel material used in the manufacturing method thereof will be described.
  • the chemical composition of the non-oriented electrical steel sheet indicates the content when the base material excluding the coating, etc. is taken as 100%.
  • the upper limit value of a certain numerical range may be replaced by the upper limit value of another numerical range described in stages, or may be replaced by a value shown in the examples.
  • the lower limit value of a certain numerical range may be replaced by the lower limit value of another numerical range described in stages, or may be replaced by a value shown in the examples.
  • the non-oriented electrical steel sheet according to this embodiment has a chemical composition in which ferrite-austenite transformation (hereinafter, ⁇ - ⁇ transformation) can occur, In mass percent, C: 0.0100% or less, Si: 1.50% to 4.00%, sol.
  • ⁇ - ⁇ transformation ferrite-austenite transformation
  • Al 0.0001% to 1.0%, S: 0.0100% or less, N: 0.0100% or less, Mn: 0.10% or more, One or more selected from Mn, Ni, and Cu: less than 2.50% in total; Mo: 0.0% to less than 2.5% Cr: 0.0% to less than 2.5% Ti: 0.000% to 0.005% Nb: 0.000% to 0.005% Sn: 0.000% to 0.400%, Sb: 0.000% to 0.400%, P: 0.000% to 0.400%, and one or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total, and further, the contents of C, Si, P, sol. Al, Mn, Mo, Cu, Cr, and Ni satisfy the specified conditions described later, with the balance being Fe and impurities.
  • one or more elements selected from Mn, Ni, Co, Pt, Pb, Au, and Cu are contained in a total amount of less than 2.50%.
  • impurities examples include those contained in raw materials such as ores and scraps, and those contained during the manufacturing process.
  • C 0.0100% or less
  • the C content is set to 0.0100% or less.
  • the reduction in the C content contributes to the uniform improvement of the magnetic properties in all directions in the sheet surface.
  • the content is preferably 0.0005% or more.
  • Si 1.50% to 4.00% Silicon increases electrical resistance, reduces eddy current loss, reduces iron loss, increases the yield ratio, and improves punching workability into iron cores. If the Si content is less than 5.0%, these effects cannot be sufficiently 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 and the hardness decreases. An excessive increase in Si content reduces punching workability and makes cold rolling difficult. Therefore, the Si content is set to 4.00% or less.
  • sol.Al 0.0001% to 1.0%
  • Sol. Al increases electrical resistance, reduces eddy current loss, and reduces iron loss.
  • Sol. Al also contributes to improving the relative magnitude of magnetic flux density B50 with respect to saturation magnetic flux density. If the sol. Al content is less than 0.0001%, these functions and effects cannot be fully obtained. Furthermore, Al also has the effect of promoting desulfurization in steelmaking. Therefore, the sol. Al content is set to 0.0001% or less. On the other hand, if the sol. Al content exceeds 1.0%, the magnetic flux density decreases, the yield ratio decreases, and punching workability decreases. shall be 1.0% or less.
  • sol. Al means acid-soluble Al that is not in the form of an oxide such as Al 2 O 3 and is soluble in acid.
  • the magnetic flux density B50 is the magnetic flux density in a magnetic field of 5000 A/m.
  • S is not an essential element and is contained, for example, as an impurity in steel. S inhibits recrystallization and grain growth during annealing by precipitating fine MnS. Therefore, the lower the S content, the lower the Such an increase in core loss and a decrease in magnetic flux density due to the inhibition of recrystallization and grain growth are remarkable when the S content exceeds 0.0100%. For this reason, the S content is set to 0.0100 Although there is no particular lower limit for the S content, it is preferable to set the S content to 0.0003% or more in consideration of the cost of desulfurization treatment during refining.
  • N 0.0100% or less
  • the Nitrogen content be 0.0010% or more.
  • the lower limit of the total content of Mn, Ni, and Cu is not particularly limited, but may be, for example, 0.10% or more, 0.50% or more, 1.00% or more, or even 2.00% or more.
  • Mn, Ni, Co, Pt, Pb, Au, and Cu are selected from Mn, Ni, Co, Pt, Pb, Au, and Cu: less than 2.50% in total.
  • Mn, Ni, and Cu, Co, Pt, Pb, and Au also increase the anisotropy of the magnetic properties, so in this embodiment, it is preferable to keep the content of these elements less than 2.50% in total. Furthermore, since these elements reduce the magnetic flux density, it is preferable to keep the content of these elements less than 2.00% in total.
  • the lower limit of the total of Mn, Ni, Co, Pt, Pb, Au, and Cu is not particularly limited, but may be, for example, 0.10% or more, 0.50% or more, or 1.00% or more, or even 2.00% or more.
  • the alloy cost of Co, Pt, Pb, and Au is high, active addition should be avoided. Furthermore, even considering the control of the Ar 3 transformation point, which is one of the features of this embodiment, it is preferable to control the Ar 3 transformation point by containing Mn, Ni, and Cu. For this reason, the total amount of Co, Pt, Pb, and Au should be less than 0.5%, more preferably 0.1% or less, and should be kept within the range of unavoidable elements, and there is no need to actively add them (it may be 0%).
  • the non-oriented electrical steel sheet and steel material according to this embodiment further satisfy the following condition as a condition under which ⁇ - ⁇ transformation can occur:
  • the C content is [C]
  • the Mo content is [Mo]
  • the Cr content is [Cr]
  • the Mn content is [Mn]
  • the Ni content is [Ni]
  • the Cu content is [Cu]
  • the Si content is [Si]
  • the sol. Al content is [sol. Al]
  • the P content is [P] in mass%
  • the transformation temperature Ar 3 (°C) defined by the following formula (1) is 750 to 1050°C.
  • Ar 3 (°C) 1020-325 ⁇ [C]+33 ⁇ [Si]+287 ⁇ [P]+80 ⁇ [sol.
  • the transformation point is not in an appropriate temperature range, so sufficient magnetic flux density cannot be obtained even if the manufacturing method described below is applied. If the Ar3 transformation point is less than 750 ° C, the hot rolling temperature is lowered, so the deformation resistance increases and the load on the rolling mill becomes too large, and the amount of added elements increases, which leads to a decrease in toughness of the hot-rolled sheet and the cold-rolled sheet, so this value is set as the lower limit.
  • Mn lowers the Ar3 transformation point, and in the component system of the non-oriented electrical steel sheet according to this embodiment, it is possible to refine the crystal grains of the hot-rolled sheet by phase transformation.
  • Mn is an element that increases the electrical resistance of steel and reduces iron loss. Therefore, Mn is contained at 0.1% or more. From this viewpoint, Mn is preferably contained at 0.5% or more. More preferably, it is contained at 1.0% or more.
  • Mn is an element that is prone to segregation, and if the content increases, not only does it cause cold work cracks due to segregation, but it also reduces the saturation magnetic flux density and prevents the increase in the magnetic flux density of the steel sheet. In addition, MnS is generated excessively, and the cold workability is reduced. Therefore, the upper limit of the Mn content is less than 2.5%. The upper limit of the Mn content is preferably 2.3 mass% or less, and more preferably 2.0 mass%.
  • Cu is an element that increases the electrical resistance of the steel sheet and reduces iron loss, similar to Mn, and reduces the Ar3 transformation point, enabling the fineness of the hot-rolled sheet grain size by phase transformation in the chemical composition of the non-oriented electrical steel sheet according to this embodiment.
  • the Cu content is high, it not only adversely affects the formation of texture in annealing after cold rolling due to an increase in recrystallization temperature, and causes embrittlement in the hot state, but also reduces the saturation magnetic flux density and prevents the increase in the magnetic flux density of the steel sheet, so caution is required.
  • Ni in an amount equal to or more than half the Cu content, embrittlement in the hot state caused by Cu can be reduced.
  • the upper limit of the Cu content is not limited, but is less than 2.5%. In addition, the upper limit of the Cu content is preferably 1.5 mass% or less, and more preferably 1.0 mass% or less.
  • the lower limit of the Cu content is not particularly limited, but may be, for example, 0.01% or more.
  • Ni (Ni: less than 2.5% in total with the above elements) Ni, like Mn, increases the electrical resistance of the steel sheet and reduces iron loss. Ni further lowers the A3 transformation point, enabling the crystal grains to be refined by phase transformation in the chemical composition of the non-oriented electrical steel sheet according to this embodiment.
  • the upper limit of the Ni content is not limited, but is less than 2.5%. In addition, the upper limit of the Ni content is preferably 1.0 mass% or less, and more preferably 0.7 mass% or less.
  • the lower limit of the Ni content is not particularly limited, but may be, for example, 0.01% or more.
  • Mo 0.0% to less than 2.58%
  • Mo is an element that lowers the Ar3 transformation point and enables the refinement of the grain size of the hot-rolled sheet by phase transformation in the chemical composition of the non-oriented electrical steel sheet according to this embodiment. Therefore, Mo may be contained as necessary, and it is preferable to contain 0.1% or more. On the other hand, since the inclusion of 2.5% or more of Mo significantly reduces the cold workability, the Mo content is set to less than 2.5%.
  • Cr 0.0% to less than 2.5%)
  • Cr is an element that lowers the Ar3 transformation point and enables the refinement of the grain size of the hot-rolled sheet by phase transformation in the chemical composition of the non-oriented electrical steel sheet according to this embodiment, and has the effect of improving not only strength adjustment and corrosion resistance, but also high-frequency characteristics in particular. Therefore, Cr may be contained as necessary, and it is preferable to contain 0.1% or more.
  • excessive Cr content not only saturates the effect and increases the raw material cost, but also reduces the saturation magnetic flux density and prevents the magnetic flux density of the steel sheet from increasing. For this reason, the Cr content is set to less than 2.5%.
  • Ti when present in the form of a solid solution or TiN, suppresses recrystallization and contributes to refinement of the austenite grain size. Therefore, Ti may be added as necessary, and it is recommended that Ti content be 0.001% or more. On the other hand, if the Ti content exceeds 0.005%, various precipitates such as TiN, TiS, and TiC are formed, which deteriorates the core loss characteristics, so the Ti content is set to 0.005% or less.
  • Nb when present in the form of a solid solution or NbN, suppresses recrystallization and contributes to refinement of the austenite grain size. Therefore, Nb may be added as necessary, and it is recommended that Nb be added in an amount of 0.001% or more. On the other hand, if the Nb content exceeds 0.005%, various precipitates such as NbN and NbC are generated and the core loss characteristics are deteriorated, so the Nb content is set to 0.005% or less.
  • Sn and Sb improve the texture after cold rolling and recrystallization, and increase the magnetic flux density. Therefore, these elements may be added as necessary, but if they are included in excess, the steel may become Therefore, the Sn content and the Sb content are both set to 0.400% or less. P may be added to ensure the hardness of the steel sheet after recrystallization, but excessive P should not be added. Therefore, the P content is set to 0.400% or less.
  • Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd react with S in the molten steel during casting of the molten steel to form precipitates of sulfides or oxysulfides, or both.
  • Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn and Cd may be collectively referred to as "coarse precipitate forming elements”.
  • the particle size of the precipitates of the coarse precipitate forming elements is about 1 ⁇ m to 2 ⁇ m, which is much larger than the particle size (about 100 nm) of fine precipitates such as MnS, TiN, AlN, TiC, and NbC. For this reason, these fine precipitates adhere to the precipitates of the coarse precipitate forming elements, and are less likely to inhibit recrystallization and grain growth during annealing such as intermediate annealing. In order to fully obtain these effects, it is preferable that the total amount of the coarse precipitate forming elements is 0.0005% or more.
  • the total content of these elements exceeds 0.0100%, the total amount of sulfides or oxysulfides or both will be excessive, inhibiting recrystallization and grain growth during annealing such as intermediate annealing. Therefore, the total content of the elements that form coarse precipitates is set to 0.0100% or less.
  • the remainder of the chemical composition other than those described above may be Fe and impurities.
  • Impurities refer to elements that are mixed in the steel raw materials and/or the steelmaking process.
  • other elements may be contained in place of a portion of Fe to the extent that the effect of the present invention is not lost.
  • B, O, V, Bi, W, and Y may each be contained in an amount of 0.10% or less.
  • the total amount of impurities is preferably 5.00% or less, and more preferably 1.00% or less.
  • the chemical composition is determined by the following method.
  • the chemical composition may be measured by a general analysis method for steel.
  • the chemical composition may be measured using ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry).
  • the chemical composition is specified by measuring a test piece taken from the steel plate with a predetermined measuring device under conditions based on a calibration curve created in advance.
  • C and S may be measured using a combustion-infrared absorption method
  • N may be measured using an inert gas fusion-thermal conductivity method.
  • O may be measured using an inert gas fusion-non-dispersive infrared absorption method. If the surface has an insulating coating, it may be mechanically removed using a minitor or the like before being subjected to analysis.
  • 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 0.10 to 0.50 mm. Normally, as the sheet thickness becomes thinner, the iron loss becomes lower, but the magnetic flux density becomes lower. In view of this, if the sheet thickness is 0.10 mm or more, the iron loss becomes lower and the magnetic flux density becomes higher. Furthermore, if the sheet thickness is 0.50 mm or less, low iron loss can be maintained.
  • the metal structure of the non-oriented electrical steel sheet according to this embodiment will be described.
  • the non-oriented electrical steel sheet of each embodiment will be specified based on the metal structure after skin pass rolling and the metal structure after final annealing.
  • the metal structure to be identified in this embodiment is identified in a cross section parallel to the plate surface of the steel plate, and is identified by the following procedure.
  • the sample is polished to a thickness of 7/8 so that the 1/8 thickness position is exposed, and the polished surface (polished surface polished to 1/8 from the plate surface side of the steel plate) is observed by EBSD (Electron Back Scattering Diffraction) using an SEM at an acceleration voltage of 25 kV and a magnification of 1000 times.
  • the observation field is 500 ⁇ m ⁇ 500 ⁇ m for the sample after skin pass rolling and 2000 ⁇ m ⁇ 2000 ⁇ m for the sample after stress relief annealing. Observation may be performed at several locations divided into several small sections.
  • the step interval during measurement is 0.3 ⁇ m for the sample after skin pass rolling and 2.0 ⁇ m for the sample after stress relief annealing.
  • the area of each orientation can be obtained by calculating the IPF (Inverse Pole Figure) from the EBSD observation field of view.
  • the KAM value can be obtained by calculating the orientation difference between measurement points using software such as OIM Analysis.
  • OIM Analysis 7.3 is used to set the limit (tolerance) for entering the KAM value to an orientation difference of 5° or less with adjacent pixels, and the average value of the calculated orientation difference between the nearest ( 1st neighbor) measurement points is used as the KAM value. Note that the setting of "Set zero point kernel to maximum misorientations" is left as the default and checked.
  • S tot Total area (observation area)
  • S tyl Total area of oriented grains with Taylor factor M exceeding 2.9 according to the following formula (2)
  • S tra Total area of oriented grains with Taylor factor M of 2.9 or less according to the following formula (2)
  • S 411 Total area of ⁇ 411 ⁇ oriented grains
  • S 100 Total area of ⁇ 100 ⁇ oriented grains
  • K tyl Average KAM value of oriented grains with Taylor factor M exceeding 2.9 according to the following formula (2)
  • K 411 Average KAM value of ⁇ 411 ⁇ oriented grains
  • the orientation tolerance of the crystal plane orientation is 10°.
  • the orientation tolerance is also 10°.
  • crystal grains having a plane orientation within ⁇ 10° of the specific plane orientation described in this disclosure are treated as crystal grains having that specific crystal orientation.
  • the Taylor factor M above is the Taylor factor when it is assumed that crystal slip deformation occurs in the slip plane ⁇ 110 ⁇ or ⁇ 112 ⁇ and in the slip direction ⁇ 111>, and no deformation occurs in the plate width direction, but compression deformation occurs in the plate thickness direction and elongation deformation occurs in the rolling direction.
  • each oriented grain satisfies the following formula (3) and formulas (4) to (6).
  • the ⁇ 100 ⁇ orientation is one orientation that is likely to exist in non-oriented electrical steel sheets. This orientation grain competes with the ⁇ 411 ⁇ orientation grains that should be preferentially grown.
  • the abundance ratio of ⁇ 411 ⁇ orientation grains is specified to be secured among orientations that have a relatively small Taylor factor and are unlikely to accumulate strain due to processing.
  • the area ratio S 411 /S 100 is greater than 1.00. In other words, there are more ⁇ 411 ⁇ oriented grains than ⁇ 100 ⁇ oriented grains. By sufficiently suppressing the growth of ⁇ 100 ⁇ oriented grains and making the ⁇ 411 ⁇ oriented grains the main orientation, the magnetic properties are improved on an average around the circumference (average of the rolling direction, width direction, direction at 45 degrees to the rolling direction, and direction at 135 degrees to the rolling direction).
  • the area ratio S 411 /S 100 is preferably 2.0 or more, and more preferably 3.0 or more.
  • the upper limit of the area ratio S411 / S100 does not need to be particularly limited. There is no problem even if the number of ⁇ 100 ⁇ oriented grains is zero and the value of the area ratio S411 / S100 is infinite. However, since reducing the number of ⁇ 100 ⁇ oriented grains to zero substantially imposes a large burden on manufacturing, the area ratio S411 / S100 is preferably 20 or less , more preferably 10 or less.
  • S tyl is the amount of orientations with relatively large Taylor factors.
  • the area ratio S tyl /S tot is defined as the area ratio S tyl /S tot to the total area, and the area ratio S tyl /S tot is set to 0.20 or more.
  • the area ratio S tyl /S tot is preferably 0.30 or more, more preferably 0.50 or more.
  • the upper limit of the area ratio S tyl /S tot is related to the amount of crystal orientation grains to be developed in the strain-induced grain growth process described below, but the condition is not simply determined by the ratio of the orientation that grows preferentially and the orientation that is encroached upon.
  • the area ratio S 411 /S tot of the ⁇ 411 ⁇ orientation grains to be developed in the strain-induced grain growth is 0.05 or more, so the area ratio S tyl /S tot is inevitably 0.95 or less.
  • the amount of the area ratio S tyl /S tot is excessive, preferential growth of the ⁇ 411 ⁇ orientation grains does not occur in relation to the strain described below.
  • the area ratio S tyl /S tot is 0.85 or less.
  • the area ratio S tyl /S tot is preferably 0.75 or less, more preferably 0.70 or less.
  • ⁇ 411 ⁇ orientation grains are preferentially grown.
  • the ⁇ 411 ⁇ orientation is one of the orientations in which the Taylor factor is relatively small and strain caused by processing is unlikely to accumulate, and is an orientation that can preferentially grow in the strain-induced grain growth process.
  • the presence of ⁇ 411 ⁇ orientation grains is essential, and in the first embodiment, the area ratio S 411 /S tot of the ⁇ 411 ⁇ orientation grains is set to 0.05 or more. If the area ratio S 411 /S tot of the ⁇ 411 ⁇ orientation grains is less than 0.05, the ⁇ 411 ⁇ orientation grains will not develop sufficiently due to the subsequent strain-induced grain growth.
  • the area ratio S 411 /S tot is preferably 0.10 or more, more preferably 0.20 or more.
  • the upper limit of the area ratio S 411 /S tot is determined according to the amount of crystal orientation grains to be eroded by strain-induced grain growth.
  • the area ratio S tyl /S tot of the orientation in which the Taylor factor to be eroded by strain-induced grain growth exceeds 2.9 is 0.20 or more, so the area ratio S 411 /S tot is 0.80 or less.
  • the area ratio S 411 /S tot is preferably 0.60 or less, more preferably 0.50 or less, and even more preferably 0.40 or less.
  • orientation grains that should be preferentially grown
  • these orientation grains compete with the ⁇ 411 ⁇ orientation grains that should be preferentially grown.
  • these orientation grains do not have as many easy axis of magnetization ( ⁇ 100> direction) in the steel sheet plane as the ⁇ 411 ⁇ orientation grains, and it is difficult to randomize the orientation selectivity in the steel sheet plane.
  • the presence ratio of ⁇ 411 ⁇ orientation grains is specified to be ensured among orientations that have a sufficiently small Taylor factor and are less likely to accumulate distortion due to processing.
  • the area of the oriented grains with a Taylor factor of 2.9 or less, including the oriented grains that are considered to compete with the ⁇ 411 ⁇ oriented grains in strain-induced grain growth, is defined as S tra .
  • the area ratio S 411 /S tra is set to 0.50 or more to ensure the superiority of the growth of the ⁇ 411 ⁇ oriented grains. If the area ratio S 411 /S tra is less than 0.50, the ⁇ 411 ⁇ oriented grains do not develop sufficiently due to strain-induced grain growth.
  • the area ratio S 411 /S tra is preferably 0.80 or more, more preferably 0.90 or more.
  • the ⁇ 411 ⁇ oriented grains can be reliably grown and better magnetic properties can be obtained.
  • the following formula (7) must be satisfied as a rule regarding the distortion. K 411 /K tyl ⁇ 0.990 (7)
  • Formula (7) is the ratio of the strain (average KAM value) accumulated in ⁇ 411 ⁇ oriented grains to the strain (average KAM value) accumulated in oriented grains with a Taylor factor of more than 2.9.
  • the KAM value is the orientation difference between adjacent measurement points within the same grain, and the KAM value is high at locations with a lot of strain. From a crystallographic point of view, for example, when compressive deformation is performed in the thickness direction in a plane strain state in a plane parallel to the thickness direction and the rolling direction, that is, when a steel sheet is simply rolled, the ratio K 411 /K tyl of K 411 to K tyl is generally smaller than 1.
  • K411 / Ktyl is set to 0.990 or less. If K411 / Ktyl exceeds 0.990, the specificity of the region to be encroached is lost, making it difficult for strain-induced grain growth to occur. K411 / Ktyl is preferably 0.970 or less, more preferably 0.950 or less.
  • the grain size is not particularly limited. This is because the relationship with the grain size is not very strong in the state in which appropriate strain-induced grain growth occurs due to the subsequent final annealing. In other words, whether the desired appropriate strain-induced grain growth occurs can be determined largely by the chemical composition of the steel sheet, as well as the relationship between the abundance (area) of each crystal orientation and the relationship between the amount of strain for each orientation.
  • the practical average crystal grain size is 300 ⁇ m or less. More preferably, it is 100 ⁇ m or less, even more preferably, it is 50 ⁇ m or less, and particularly preferably, it is 30 ⁇ m or less. The finer the crystal grain size, the easier it is to recognize the development of the desired crystal orientation due to strain-induced grain growth when the crystal orientation and strain distribution are appropriately controlled.
  • the average crystal grain size is 3 ⁇ m or more, more preferably, 8 ⁇ m or more, and even more preferably, 15 ⁇ m or more.
  • Embodiment 2 In the above-mentioned embodiment 1, the characteristics of the steel sheet are specified by specifying the strain of the steel sheet by the KAM value. In contrast, in embodiment 2, the steel sheet described in embodiment 1 is annealed for a sufficiently long time and further grain-grown is specified. In such a steel sheet, strain-induced grain growth is almost completed, and as a result, the strain is almost completely released, so that the characteristics are very favorable. In other words, a steel sheet in which ⁇ 411 ⁇ orientation grains are grown by strain-induced grain growth and then normal grain growth is performed by final annealing until the strain is almost completely released becomes a steel sheet with stronger accumulation in the ⁇ 411 ⁇ orientation.
  • Formula (8) has a different numerical range compared to formula (3) related to the non-oriented electrical steel sheet after the above-mentioned skin-pass rolling.
  • the strain-induced grain growth occurring during the final annealing causes the ⁇ 411 ⁇ orientation grains to grow further and increase their area, improving the magnetic properties on the circumferential average (average of the rolling direction, width direction, 45-degree direction relative to the rolling direction, and 135-degree direction relative to the rolling direction).
  • the definitions of formulas (9) to (11) have different numerical ranges compared to formulas (4) to (6) related to the non-oriented electrical steel sheet after skin-pass rolling described above.
  • the area ratio S tyl /S tot is less than 0.55.
  • the total area S tyl may be zero.
  • the upper limit of the area ratio S tyl /S tot is determined as one of the parameters indicating the degree of progress of the growth of the ⁇ 411 ⁇ oriented grains.
  • the area ratio S tyl /S tot being 0.55 or more indicates that the oriented grains having a Taylor factor of more than 2.9 that should be eaten at the stage of strain-induced grain growth are not eaten sufficiently. In this case, the magnetic properties are not sufficiently improved.
  • the area ratio S tyl /S tot is preferably 0.40 or less, more preferably 0.30 or less. Since the area ratio S tyl /S tot is preferably small, the lower limit is not specified and may be 0.00.
  • the area ratio S411 / Stot is set to be more than 0.30. If the area ratio S411 / Stot is 0.30 or less, the magnetic properties are not sufficiently improved.
  • the area ratio S411 / Stot is preferably 0.40 or more, more preferably 0.50 or more.
  • the situation where the area ratio S411 / Stot is 1.00 means that all the crystal structure is oriented in the ⁇ 411 ⁇ direction and no other oriented grains exist, and the second embodiment is also intended for this situation.
  • the relationship between the ⁇ 411 ⁇ oriented grains and the ⁇ 411 ⁇ oriented grains, which are considered to have competed with the ⁇ 411 ⁇ oriented grains in the strain-induced grain growth, is also important.
  • the area ratio S 411 /S tra is sufficiently large, the superiority of the ⁇ 411 ⁇ oriented grains is ensured even in the situation of normal grain growth after the strain-induced grain growth, and the magnetic properties are good.
  • the area ratio S 411 /S tra is set to 0.60 or more.
  • the area ratio S 411 /S tra is preferably 0.70 or more, more preferably 0.80 or more.
  • there is no need to set a particular upper limit for the area ratio S 411 /S tra and all grains having a Taylor factor of 2.9 or less may be grains having the ⁇ 411 ⁇ orientation.
  • the practical average crystal grain size of the ⁇ 411 ⁇ orientation grains which are relatively coarse grains in the second embodiment, is preferably 500 ⁇ m or less. More preferably, the average crystal grain size of the ⁇ 411 ⁇ orientation grains is 400 ⁇ m or less, even more preferably 300 ⁇ m or less, and particularly preferably 200 ⁇ m or less.
  • the lower limit of the average crystal grain size of the ⁇ 411 ⁇ orientation grains is preferably 40 ⁇ m or more, more preferably 60 ⁇ m or more, and even more preferably 80 ⁇ m or more, assuming that sufficient preferential growth of the ⁇ 411 ⁇ orientation is ensured.
  • the non-oriented electrical steel sheet of embodiment 2 has the best magnetic properties in the 45° direction among the three directions that form angles of 0°, 45°, and 90° with the rolling direction.
  • the magnetic properties in the 45° direction are the average value of the magnetic properties in the two directions that form angles of +45° and -45° with the rolling direction.
  • the magnetic flux density B50 in the direction at 45° to the rolling direction is preferably not less than 1.75 T. Note that in the non-oriented electrical steel sheet according to embodiment 2, the magnetic flux density in the direction at 45° to the rolling direction is high, the in-plane anisotropy is small, and a high magnetic flux density can be obtained even in the circumferential average (all-direction average).
  • the magnetic flux density B50 value in the rolling direction is B50L
  • the magnetic flux density B50 value in the 45° direction to the rolling direction is B50D
  • the magnetic flux density B50 value in the 90° direction to the rolling direction is B50C .
  • the magnetic flux density can be measured by cutting a 55 mm square sample at 45°, 0°, etc., relative to the rolling direction and using a single sheet magnetic measuring device.
  • Magnetic measurements may be performed using the methods described in JIS C 2550-1 (2011) and JIS C 2550-3 (2019), or the methods described in JIS C 2556 (2015).
  • the electromagnetic circuit may be measured using a 55 mm square test piece conforming to JIS C 2556 (2015), or a device capable of measuring even smaller test pieces.
  • the non-oriented electrical steel sheet according to the present embodiment is obtained by a production method including a hot rolling step, a cold rolling step, an intermediate annealing step, a skin pass rolling step, and a final annealing step. Preferred conditions for each step will now be described.
  • the Ar3 temperature is the transformation temperature Ar3 (°C) defined by the above formula (1).
  • Hot rolling process In the hot rolling process, hot rolling is performed on the steel material satisfying the above-mentioned chemical composition to produce a hot rolled steel sheet.
  • the hot rolling process includes a heating process and a rolling process.
  • the steel material is, for example, a slab produced by normal continuous casting, and steel material of the above-mentioned composition is produced by a well-known method.
  • molten steel is produced in a converter or electric furnace.
  • the produced molten steel is subjected to secondary refining in a degassing facility or the like to produce molten steel having the above-mentioned chemical composition (the chemical composition does not change substantially in subsequent processes).
  • the molten steel is cast into a slab by a continuous casting method or an ingot casting method.
  • the cast slab may be rolled into blooms.
  • the steel material having the above-mentioned chemical composition it is preferable to heat the steel material having the above-mentioned chemical composition to 1000 to 1200°C.
  • the steel material is placed in a heating furnace or a soaking furnace and heated in the furnace.
  • the holding time at the above-mentioned heating temperature in the heating furnace or soaking furnace is not particularly limited, but is, for example, 30 to 200 hours.
  • Hot rolling In the rolling process, multiple passes of rolling are performed on the steel material heated in the heating process to produce hot-rolled steel plate.
  • “pass” means that the steel plate passes through one rolling stand having a pair of work rolls and is reduced.
  • Hot rolling may be performed, for example, by tandem rolling using a tandem rolling mill including multiple rolling stands arranged in a row (each rolling stand having a pair of work rolls) to perform multiple passes, or by reverse rolling using a pair of work rolls to perform multiple passes. From the viewpoint of productivity, it is preferable to perform multiple rolling passes using a tandem rolling mill.
  • the steel material is, for example, a slab manufactured by normal continuous casting.
  • the slab is heated to the Ar 3 temperature or higher, which is a temperature range in which the steel structure becomes a ⁇ phase.
  • Hot rolling is started in a temperature range in which the steel structure becomes a ⁇ phase (hereinafter, this temperature range may be described as the ⁇ range), and is performed in the ⁇ range except for a necessary number of passes including the final pass of the finish rolling, and is completed by performing a necessary number of passes including the final pass in a temperature range in which the ⁇ phase exists in the steel structure (hereinafter, this temperature range may be described as the ⁇ range).
  • the front to middle stages of rough rolling and finish rolling are performed in the ⁇ range, and the rear stage of finish rolling is performed in the ⁇ range.
  • the reduction ratio in the temperature range from the Ar 3 temperature or higher to Ar 3 +20°C or lower immediately before the final rolling in the ⁇ range is 10% or more.
  • the rolling reduction in the temperature range of the finish rolling temperature FT or higher and lower than the Ar 3 temperature is set to 15% or more in total, taking into consideration the case where rolling is performed in multiple passes.
  • the finish rolling temperature FT refers to the surface temperature of the hot-rolled steel sheet immediately after finish rolling.
  • the lower limit of the finish rolling temperature FT is not particularly limited, but is set to, for example, Ar3 temperature -100°C or more.
  • Rolling in a temperature range above Ar3 + 20°C just before the final rolling in the ⁇ region has almost no effect on the grain size of the deformed ⁇ grains before the phase transformation, and coarse deformed ⁇ grains are formed after the transformation, which is unrelated to the accumulation in the ⁇ 411 ⁇ crystal orientation in the final product. If the rolling reduction ratio in the temperature range from Ar3 temperature to Ar3 + 20°C just before the final rolling in the ⁇ region is less than 10%, the accumulation of strain in the processed ⁇ grains before the phase transformation is insufficient, coarse processed ⁇ grains are formed, and accumulation in the ⁇ 411 ⁇ crystal orientation in the final product becomes difficult.
  • the rolling reduction ratio in the temperature range from Ar3 temperature to Ar3 + 20°C is preferably 15% or more, more preferably 20% or more.
  • the lower limit temperature for rolling in the ⁇ region is not particularly limited, but since a lower rolling temperature increases the load on the rolling mill, it is preferable to set the lower limit temperature to 600° C. or higher.
  • the rolling temperature may fluctuate above or below the specified judgment temperature ( Ar3 temperature, or Ar3 + 20°C) during the rolling pass due to the competition between the temperature drop caused by roll contact and cooling lubricant and the temperature rise caused by processing. In this embodiment, such a situation is handled as follows.
  • the temperature on the entry side is TPI (°C)
  • the thickness on the entry side is TCI (mm)
  • the temperature on the exit side is TPO (°C)
  • the thickness on the exit side is TCO (mm)
  • the above assumption also assumes that the exit temperature of the rolling pass is higher than the entry temperature.
  • the exit temperature of the rolling pass is higher than the entry temperature.
  • the temperature fluctuations on either side of the Ar 3 temperature may occur over multiple passes.
  • the rolling conditions in the ⁇ region are the "final rolling process in the ⁇ region".
  • the rolling conditions in the ⁇ region are the “rolling process in the ⁇ region immediately before the above-mentioned "final rolling process in the ⁇ region".
  • the rolling temperature after starting hot rolling in the ⁇ region changes as follows: ⁇ region (start of hot rolling) ⁇ ⁇ region 1 ⁇ ⁇ region 1 ⁇ ⁇ region 2 ⁇ ⁇ region 2 ⁇ ⁇ region 3 (end of hot rolling), if the ⁇ region 3 and the ⁇ region 2 meet the conditions of this embodiment, it is possible to obtain the disclosed steel sheet.
  • the rolling temperature in each pass can be measured, for example, by a thermometer installed at the entry or exit of the rolling stand that performs the reduction of the target pass. It is not necessary to install thermometers at the entry and exit of all rolling stands whose temperature range falls within the range disclosed herein, and the rolling temperature at intermediate rolling stands may be calculated from the actual temperatures of thermometers appropriately installed before and after them. Rather, in current hot rolling, control using such calculated temperatures is usually performed.
  • the finish rolling temperature FT is preferably set to be lower than the Ar3 temperature.
  • the hot-rolled steel sheet is coiled without annealing the hot-rolled sheet.
  • the temperature during coiling is preferably more than 450°C and less than 650°C.
  • Cold rolling process In the cold rolling process, the hot rolled steel sheet after the cooling process is cold rolled to obtain a cold rolled steel sheet. Specifically, after hot rolling, the hot rolled steel sheet is pickled and then cold rolled. In the cold rolling, the reduction is preferably 80% to 92%. Note that the higher the reduction, the easier it is for crystal grains having the ⁇ 411 ⁇ crystal orientation to grow due to subsequent bulging, but the sheet shape deteriorates and operation becomes more difficult.
  • the rolling shape ratio is 5.0 or less.
  • intermediate annealing is performed on the cold-rolled steel sheet.
  • the temperature of intermediate annealing is controlled to less than 900°C.
  • the temperature of intermediate annealing is preferably 800°C or less, more preferably 750°C or less. If the temperature of intermediate annealing is 900°C or more, excessive grain growth of crystal grains will occur, and even if skin-pass rolling and final annealing are performed as described below, accumulation in the ⁇ 411 ⁇ crystal orientation will be difficult to proceed.
  • the temperature of intermediate annealing is preferably 600°C or more, more preferably 700°C or more.
  • the temperatures described here are based on continuous annealing, and the intermediate annealing time is preferably in the range of 5 to 120 seconds.
  • the annealing temperature range and annealing time range are suitable conditions for allowing the ⁇ 411 ⁇ crystal grains, which have already formed in no small amount by the cold rolling step, to grow appropriately by bulging, and for creating a state in which strain-induced grain growth is likely to occur by the skin-pass rolling and final annealing described below.
  • the crystal grains having the ⁇ 411 ⁇ crystal orientation are less likely to accumulate strain due to skin pass rolling, while the crystal grains belonging to the orientation group having the ⁇ 111 ⁇ plane orientation called ⁇ -fiber, such as ⁇ 111 ⁇ 112> and ⁇ 111 ⁇ 110>, tend to accumulate strain, and the crystal grains having the ⁇ 411 ⁇ crystal orientation with less strain in the subsequent annealing use the difference in strain as a driving force to eat away at these ⁇ -fiber orientation grains.
  • This encroachment phenomenon that occurs with the difference in strain as a driving force is called strain induced grain boundary migration (hereinafter, SIBM). It is preferable that the reduction ratio of the skin pass rolling is 5% to less than 25%.
  • the reduction rate is less than 5%, the amount of strain is too small, so that the subsequent annealing does not cause strain-induced grain boundary migration (hereinafter, SIBM), and the crystal grains having the ⁇ 411 ⁇ crystal orientation do not become large.
  • SIBM strain-induced grain boundary migration
  • the reduction rate is 25% or more, the amount of strain becomes too large, and recrystallization nucleation (hereinafter, nucleation) occurs, in which new crystal grains are born from crystal grains having the ⁇ -fiber orientation. In this nucleation, most of the grains born are crystal grains having the ⁇ -fiber orientation, so the magnetic properties become poor. From the viewpoint of increasing the average magnetic flux density in the sheet surface and reducing the anisotropy, it is more preferable to set the reduction rate of the skin pass rolling to 5% to 15%.
  • non-oriented electrical steel sheet is to have the above-mentioned strain distribution
  • the reduction rate RR1 (%) in cold rolling is defined as follows.
  • Reduction rate RR1 (%) (1 - thickness after the final pass of cold rolling / thickness before the first pass of cold rolling) x 100
  • the reduction ratio RR2 (%) in skin pass rolling is defined as follows.
  • Reduction rate RR2 (%) (1 - thickness after the final pass of skin pass rolling / thickness before the first pass of skin pass rolling) x 100
  • the steel sheet after the skin pass rolling is subjected to final annealing.
  • This final annealing generates SIBM driven by the strain difference for each crystal orientation due to skin pass rolling, and crystal grains having the ⁇ 411 ⁇ crystal orientation targeted by the present disclosure grow preferentially, increasing the ⁇ 411 ⁇ crystal orientation concentration of the steel sheet.
  • This annealing condition can be appropriately set by a person skilled in the art while confirming the occurrence of SIBM, and is not particularly limited, but examples include annealing at 700 to 950 ° C for 1 to 100 seconds in the case of continuous annealing and annealing at 650 to 850 ° C for 0.5 to 2 hours in the case of batch annealing.
  • the non-oriented electrical steel sheet according to this embodiment can be manufactured as described above.
  • this manufacturing method is only one example of a method for manufacturing the non-oriented electrical steel sheet according to this embodiment, and is not intended to limit the manufacturing method.
  • the non-oriented electrical steel sheet according to this embodiment can be manufactured.
  • the final annealing process can be performed after skin pass rolling, for example, at a steel sheet manufacturer in the form of a steel sheet coil or as a cut sheet.
  • the steel sheet can be shipped without undergoing the final annealing process, and the motor manufacturer can process the steel sheet into a predetermined shape as a motor core, laminate the steel sheet, and then perform final annealing in the core shape.
  • this process can also be performed as "strain relief annealing" that is generally performed on motor cores at motor manufacturers.
  • the final annealing may be performed by both the steel sheet manufacturer and the motor manufacturer as two or more final annealings.
  • a steel sheet with a large amount of remaining strain or a relatively small grain size has high strength, and is particularly suitable for use as a non-oriented electrical steel sheet for a rotor core to suppress deformation due to centrifugal force accompanying the rotation of the core.
  • a steel sheet with sufficient strain release and coarse grain size is particularly suitable for use as a non-oriented electrical steel sheet for a stator core to suppress iron loss.
  • the steel member made of the non-oriented electromagnetic steel sheet according to this embodiment is applied to, for example, the iron core (motor core) of a rotating electric machine.
  • the iron core used in the rotating electric machine is produced by cutting out individual flat thin plates from the non-oriented electromagnetic steel sheet according to this embodiment and appropriately stacking these flat thin plates.
  • This iron core uses non-oriented electromagnetic steel sheet with excellent magnetic properties, so iron loss is kept low, resulting in a rotating electric machine with excellent torque.
  • the steel member made of the non-oriented electromagnetic steel sheet according to this embodiment can also be applied to products other than the iron core of a rotating electric machine, such as the iron core of a linear motor or a stationary machine (reactor or transformer).
  • non-oriented electrical steel sheet according to the embodiment of the present disclosure will be specifically described with reference to an example.
  • the example shown below is merely one example of the non-oriented electrical steel sheet according to the embodiment of the present disclosure, and the non-oriented electrical steel sheet according to the present disclosure is not limited to the example below.
  • the molten steel was cast to produce an ingot with the composition shown in Table 1 below. Note that "Co, etc.” in Table 1 indicates the respective contents of Co, Pt, Pb, and Au.
  • the produced ingot was then hot rolled under the conditions shown in Table 1 to obtain a hot-rolled sheet. Next, it was cold rolled under the conditions shown in Table 1 to obtain a cold-rolled sheet.
  • the cold-rolled sheet was subjected to intermediate annealing in a non-oxidizing atmosphere at the temperature shown in Table 2 for 30 seconds, and then subjected to a second cold rolling (skin pass rolling) at the reduction ratio shown in Table 2.
  • the cut out test piece was processed to reduce its thickness to 7/8, and the processed surface (the polished surface where the steel plate was polished to 1/8 from the plate side) was observed with EBSD (step interval: 0.3 ⁇ m) as described above. From the EBSD observation, the area and average KAM value of the oriented grains of the types shown in Table 3 were determined.
  • the steel sheet was subjected to final annealing at 800° C. for 2 hours. From the steel sheet after final annealing, a 55 mm square sample was taken as a measurement sample. At this time, a sample in which one side of the sample piece was parallel to the rolling direction and a sample inclined at 45 degrees to the rolling direction were taken. The sample taking was performed using a shearing machine. Next, in order to investigate the texture, a part of the steel sheet was cut out, the cut out test piece was processed to reduce the thickness to 7/8, and the processed surface (the polished surface obtained by polishing the steel sheet from the sheet surface side to 1/8) was observed by EBSD (step interval: 2.0 ⁇ m) in the above-mentioned manner.
  • EBSD step interval: 2.0 ⁇ m
  • the areas and average KAM values of the orientation grains of the types shown in Table 3 were obtained by EBSD observation. Then, the magnetic flux density B50L in the rolling direction, the magnetic flux density B50D in the 45° direction relative to the rolling direction, and the magnetic flux density B50C in the 90° direction relative to the rolling direction were measured in accordance with JIS C2556 (2015). The measurement results are shown in Table 3.
  • the "average value” shown in Table 3 is the average value of the magnetic flux density B50 all around (the average value of the magnetic flux density B50 in the rolling direction, the 90° direction relative to the rolling direction, and the 45° (135°) direction relative to the rolling direction).
  • the rollability was evaluated as follows: In a 1 m long region centered on a position 10 m in the longitudinal direction from the outermost longitudinal tip of the cold-rolled sheet coil (top part), a position 1/2 the total length of the coil in the longitudinal direction from the outermost longitudinal tip of the coil (middle part), and a position 10 m in the longitudinal direction from the innermost longitudinal tip of the coil (bottom part), if cracks having a length of 1 cm or more were present in a total of two or more places on both end faces in the sheet width direction of the coil, the evaluation was given as "N", and otherwise as "Y".
  • test piece was processed to reduce its thickness to half, and the processed surface was observed by EBSD in the manner described above to determine the area and average KAM value of the oriented grains of the types shown in Table 4. The results are shown in Table 4 together with the magnetic properties and rolling properties.
  • This disclosure makes it possible to provide non-oriented electrical steel sheets that have small in-plane anisotropy and excellent magnetic properties on average around the circumference (average in all directions), making them extremely useful in industry.

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Abstract

Provided is a non-oriented electromagnetic steel sheet which has a prescribed chemical composition and which, when observed by EBSD in a plane parallel to the steel sheet surface, satisfies expressions (3)-(7), where Stot is the total area, S411 is the area of {411} oriented grains, S100 is the area of {100} oriented grains, Styl is the area of oriented grains having a Taylor factor M of more than 2.9 according to expression (2), Stra is the sum total area of oriented grains having a Taylor factor M of not more than 2.9, K411 is the average KAM value of {411} oriented grains, and Ktyl is the average KAM value of oriented grains having a Taylor factor M of more than 2.9.　(2): M=(cosφ×cosλ)-1 (3): S411/S100>1.00 (4): 0.20≤Styl/Stot≤0.85 (5): 0.05≤S411/Stot≤0.80 (6): S411/Stra≥0.50 (7): K411/Ktyl≤0.990

Description

無方向性電磁鋼板Non-oriented electrical steel sheet
　本開示は、無方向性電磁鋼板に関する。 This disclosure relates to non-oriented electrical steel sheets.
　無方向性電磁鋼板は、例えばモータの鉄心に使用され、無方向性電磁鋼板には、その板面に平行な方向において優れた磁気特性、例えば低鉄損及び高磁束密度が要求される。 Non-oriented electrical steel sheets are used, for example, in the iron cores of motors, and are required to have excellent magnetic properties in the direction parallel to the plate surface, such as low core loss and high magnetic flux density.
　このためには、結晶の磁化容易軸（＜１００＞方位）が板面内方向に一致するように鋼板の集合組織を制御することが有利である。このような集合組織制御に関しては、例えば特許文献１～５に記載の技術のように、｛１００｝方位、｛１１０｝方位、｛１１１｝方位などを制御する技術が多く開示されている。 For this reason, it is advantageous to control the texture of the steel sheet so that the crystal's easy axis of magnetization (<100> orientation) coincides with the in-plane direction of the sheet. Regarding such texture control, many techniques have been disclosed for controlling the {100} orientation, {110} orientation, {111} orientation, etc., such as those described in Patent Documents 1 to 5.
　集合組織を制御する方法としては、様々な方法が考案されているが、その中に「歪誘起粒成長」を活用する技術がある。特定の条件での歪誘起粒成長においては、板面内方向に磁化容易軸を持たない｛１１１｝方位の集積を抑制することができるため、無方向性電磁鋼板では有効に活用されている。これらの技術については、特許文献６～１０などに開示されている。 Various methods have been devised for controlling the texture, including a technology that utilizes "strain-induced grain growth." Under certain conditions, strain-induced grain growth can suppress the accumulation of the {111} orientation, which does not have an easy axis of magnetization in the in-plane direction of the sheet, and is therefore effectively used in non-oriented electrical steel sheets. These technologies are disclosed in Patent Documents 6 to 10, among others.
　しかしながら、従来の方法では、｛１１１｝方位の集積を抑制することができるが、｛１１０｝＜００１＞方位（以下、Ｇｏｓｓ方位）が成長してしまう。Ｇｏｓｓ方位は｛１１１｝よりも一方向は磁気特性に優れているが、全周平均では磁気特性がほとんど改善されない。そのため、従来の方法では全周平均で優れた磁気特性が得られないという問題点がある。 However, while conventional methods can suppress the accumulation of the {111} orientation, they result in the growth of the {110}<001> orientation (hereafter referred to as the Goss orientation). The Goss orientation has better magnetic properties in one direction than the {111} orientation, but the magnetic properties are hardly improved on average around the circumference. Therefore, conventional methods have the problem of not being able to obtain excellent magnetic properties on average around the circumference.
　また、全周平均での優れた磁気特性を実現するため、γ→α相変態が起こる成分系で｛１００｝結晶方位または｛４１１｝結晶法を発達させる技術が特許文献１１～１３に開示されている。これら技術では、γ→α相変態温度が低い鋼組成とし低温で変態させることで熱延板時点で細粒のα相組織を実現しており、変態温度を低下させるとともに回復再結晶を遅らせて歪の蓄積を促進する観点で、Ｍｎ、Ｃｕ、Ｎｉ等のγ安定化元素の添加が活用される。しかし、Ｍｎは偏析元素として知られ、添加量が増加すると熱延板の板厚中心部に偏析し熱延板を冷延した際の割れの原因となる。 Furthermore, in order to achieve excellent magnetic properties on an average all around, patent documents 11 to 13 disclose technologies for developing {100} crystal orientation or {411} crystallization in a component system in which γ→α phase transformation occurs. In these technologies, a fine-grained α phase structure is achieved at the time of hot rolling by using a steel composition with a low γ→α phase transformation temperature and transforming at a low temperature, and the addition of γ-stabilizing elements such as Mn, Cu, and Ni is utilized from the viewpoint of lowering the transformation temperature and delaying recovery recrystallization to promote the accumulation of strain. However, Mn is known as a segregation element, and if the amount added is increased, it segregates in the center of the thickness of the hot-rolled sheet, causing cracks when the hot-rolled sheet is cold-rolled.
日本国特開２０１７－１９３７５４号公報Japanese Patent Application Publication No. 2017-193754 日本国特開２０１１－１１１６５８号公報Japanese Patent Application Publication No. 2011-111658 国際公開第２０１６／１４８０１０号International Publication No. 2016/148010 日本国特開２０１８－３０４９号公報Japanese Patent Application Publication No. 2018-3049 国際公開第２０１５／１９９２１１号International Publication No. 2015/199211 日本国特開平８－１４３９６０号公報Japanese Patent Application Publication No. 8-143960 日本国特開２００２－３６３７１３号公報Japanese Patent Application Publication No. 2002-363713 日本国特開２０１１－１６２８２１号公報Japanese Patent Application Publication No. 2011-162821 日本国特開２０１３－１１２８５３号公報Japanese Patent Application Publication No. 2013-112853 日本国特許第４０２９４３０号公報Japanese Patent No. 4029430 国際公開第２０２１／０９５８４６号International Publication No. 2021/095846 国際公開第２０２１／０９５８５１号International Publication No. 2021/095851 国際公開第２０２１／０９５８８０号International Publication No. 2021/095880
　本開示は、前述の問題点を鑑み、圧延性が問題とならないように、Ｍｎを抑制するとともに、ＣｕおよびＮｉなどの元素の含有量を適正化した化学組成を有する鋼板において、板面内異方性が小さく全周平均（全方向平均）が優れた磁気特性を有する無方向性電磁鋼板を提供することを目的とする。 In consideration of the above-mentioned problems, the present disclosure aims to provide a non-oriented electrical steel sheet with a chemical composition in which Mn is suppressed and the contents of elements such as Cu and Ni are optimized so that rolling properties are not an issue, and which has small in-plane anisotropy and excellent magnetic properties averaged all around (averaged in all directions).
　本発明者らは、歪誘起粒成長を活用して無方向性電磁鋼板にとって好ましい集合組織を形成するための技術について検討した。その中で、｛４１１｝＜ｕｖｗ＞方位（以下、｛４１１｝方位）の結晶粒も｛１００｝＜ｕｖｗ＞方位（以下、｛１００｝方位）と同じくらい歪の入りにくい結晶粒であることに着目した。つまり、歪誘起粒成長が起こる前の段階で、｛１００｝方位の結晶粒よりも｛４１１｝方位の結晶粒を多くすることにより、歪誘起粒成長によって主として｛４１１｝方位の結晶粒が｛１１１｝方位の結晶粒を蚕食すると同時に｛１００｝方位の結晶粒の発達を抑制し、｛４１１｝方位が主方位の無方向性電磁鋼板が製造される。このように、｛１００｝方位の結晶粒の発達を十分に抑制した上で｛４１１｝方位を主方位とすれば全周平均（圧延方向、幅方向、圧延方向に対して４５度の方向、及び圧延方向に対して１３５度の方向、の平均）の磁気特性が改善されることがわかった。 The present inventors have investigated a technique for forming a favorable texture for non-oriented electrical steel sheets by utilizing strain-induced grain growth. In the process, they have focused on the fact that {411}<uvw> orientation (hereinafter, {411} orientation) crystal grains are as resistant to strain as {100}<uvw> orientation (hereinafter, {100} orientation). In other words, by increasing the number of {411} orientation crystal grains compared to {100} orientation crystal grains at the stage before strain-induced grain growth occurs, strain-induced grain growth causes the {411} orientation crystal grains to encroach on the {111} orientation crystal grains while simultaneously suppressing the development of {100} orientation crystal grains, thereby producing a non-oriented electrical steel sheet with the {411} orientation as the main orientation. In this way, it was found that by sufficiently suppressing the development of crystal grains in the {100} orientation and making the {411} orientation the main orientation, the magnetic properties are improved on an average around the circumference (average of the rolling direction, width direction, direction at 45 degrees to the rolling direction, and direction at 135 degrees to the rolling direction).
　また、発明者らは、歪誘起粒成長が起こる前の段階で、｛１００｝方位の結晶粒よりも｛４１１｝方位の結晶粒を多くする方法について検討を行った。その結果、Ｍｎ、Ｎｉ，またはＣｕ等の含有量を低くした鋼種において特定の条件で熱間圧延を実施し、さらに冷延、焼鈍後、低めの圧下率で再冷延（スキンパス圧延）を行った後に最終焼鈍を行う方法を見出した。 The inventors also investigated a method for increasing the number of {411} oriented crystal grains relative to {100} oriented crystal grains at a stage before strain-induced grain growth occurs. As a result, they discovered a method in which hot rolling is performed under specific conditions for steel types with low contents of Mn, Ni, Cu, etc., and then cold rolling and annealing are performed, followed by re-cold rolling (skin pass rolling) at a lower reduction ratio, followed by final annealing.
　本発明者らは、このような知見に基づいて更に鋭意検討を重ねた結果、以下に示す開示の諸態様に想到した。 The inventors conducted further intensive research based on this knowledge and came up with the following aspects of the disclosure.
（１）本開示の一態様に係る無方向性電磁鋼板は、
　質量％で、
　Ｃ　：０．０１００％以下、
　Ｓｉ：１．５０％～４．００％、
　ｓｏｌ．Ａｌ：０．０００１％～１．０％、
　Ｓ　：０．０１００％以下、
　Ｎ　：０．０１００％以下、
　Ｍｎ：０．１０％以上、
　Ｍｎ、Ｎｉ、及びＣｕから選ばれる１種又は複数種：総計で２．５０％未満、
　Ｍｏ：０．０％～２．５％未満、
　Ｃｒ：０．０％～２．５％未満、
　Ｔｉ：０．０００％～０．００５％、
　Ｎｂ：０．０００％～０．００５％、
　Ｓｎ：０．０００％～０．４００％、
　Ｓｂ：０．０００％～０．４００％、
　Ｐ　：０．０００％～０．４００％、及び
　Ｍｇ、Ｃａ、Ｓｒ、Ｂａ、Ｃｅ、Ｌａ、Ｎｄ、Ｐｒ、Ｚｎ、及びＣｄからなる群から選ばれる１種又は複数種：総計で０．００００％～０．０１００％を含有し、
質量％での、Ｃ含有量を［Ｃ］、Ｍｏ含有量を［Ｍｏ］、Ｃｒ含有量を［Ｃｒ］、Ｍｎ含有量を［Ｍｎ］、Ｎｉ含有量を［Ｎｉ］、Ｃｕ含有量を［Ｃｕ］、Ｓｉ含有量を［Ｓｉ］
、ｓｏｌ．Ａｌ含有量を［ｓｏｌ．Ａｌ］、Ｐ含有量を［Ｐ］としたときに、以下の（１）式で定めた変態温度Ａｒ３（℃）が７５０～１０５０℃であり、残部がＦｅおよび不純物からなる化学組成を有し、
　さらに、鋼板表面に平行な面でＥＢＳＤにより観察したときにおいて、全面積をＳtot、｛４１１｝方位粒の面積をＳ411、｛１００｝方位粒の面積をＳ100、以下の（２）式に従うテイラー因子Ｍが２．９超となる方位粒の面積をＳtyl、前記テイラー因子Ｍが２．９以下となる方位粒の合計面積をＳtra、｛４１１｝方位粒の平均ＫＡＭ値をＫ411、前記テイラー因子Ｍが２．９超となる方位粒の平均ＫＡＭ値をＫtylとした場合に、以下の（
３）式及び（４）式～（７）式を満たす。
　Ａｒ３（℃）＝１０２０－３２５×［Ｃ］＋３３×［Ｓｉ］＋２８７×［Ｐ］＋８０×［ｓｏｌ．Ａｌ］－１２０×（［Ｍｎ］＋［Ｍｏ］＋［Ｃｕ］）－４６×（［Ｃｒ］＋［Ｎｉ］）　　　・・・（１）
　Ｍ＝（cosφ×cosλ）-1　　　・・・（２）
　Ｓ411／Ｓ100＞１．００　　　・・・（３）
　０．２０≦Ｓtyl／Ｓtot≦０．８５　　　・・・（４）
　０．０５≦Ｓ411／Ｓtot≦０．８０　　　・・・（５）
　Ｓ411／Ｓtra≧０．５０　　　・・・（６）
　Ｋ411／Ｋtyl≦０．９９０　　　・・・（７）
　ここで、（２）式中のφは応力ベクトルと結晶のすべり方向ベクトルのなす角を表し、λは応力ベクトルと結晶のすべり面の法線ベクトルのなす角を表す。
（２）本開示の一態様に係る無方向性電磁鋼板は、
　質量％で、
　Ｃ　：０．０１００％以下、
　Ｓｉ：１．５０％～４．００％、
　ｓｏｌ．Ａｌ：０．０００１％～１．０％、
　Ｓ　：０．０１００％以下、
　Ｎ　：０．０１００％以下、
　Ｍｎ：０．１０％以上、
　Ｍｎ、Ｎｉ、Ｃｏ、Ｐｔ、Ｐｂ、Ａｕ、及びＣｕから選ばれる１種又は複数種：総計で２．５０％未満、
　Ｍｏ：０．０％～２．５％未満、
　Ｃｒ：０．０％～２．５％未満、
　Ｔｉ：０．０００％～０．００５％、
　Ｎｂ：０．０００％～０．００５％、
　Ｓｎ：０．０００％～０．４００％、
　Ｓｂ：０．０００％～０．４００％、
　Ｐ　：０．０００％～０．４００％、及び
　Ｍｇ、Ｃａ、Ｓｒ、Ｂａ、Ｃｅ、Ｌａ、Ｎｄ、Ｐｒ、Ｚｎ、及びＣｄからなる群から選ばれる１種又は複数種：総計で０．００００％～０．０１００％を含有し、質量％での、Ｃ含有量を［Ｃ］、Ｍｏ含有量を［Ｍｏ］、Ｃｒ含有量を［Ｃｒ］、Ｍｎ含有量を［Ｍｎ］、Ｎｉ含有量を［Ｎｉ］、Ｃｕ含有量を［Ｃｕ］、Ｓｉ含有量を［Ｓｉ］、ｓｏｌ．Ａｌ含有量を［ｓｏｌ．Ａｌ］、Ｐ含有量を［Ｐ］としたときに、以下の（１）式で定めた変態温度Ａｒ３（℃）が７５０～１０５０℃であり、残部がＦｅおよび不純物からなる化学組成を有し、
　さらに、鋼板表面に平行な面でＥＢＳＤにより観察したときにおいて、全面積をＳtot、｛４１１｝方位粒の面積をＳ411、｛１００｝方位粒の面積をＳ100、以下の（２）式に従うテイラー因子Ｍが２．９超となる方位粒の面積をＳtyl、前記テイラー因子Ｍが２．９以下となる方位粒の合計面積をＳtra、｛４１１｝方位粒の平均ＫＡＭ値をＫ411、前記テイラー因子Ｍが２．９超となる方位粒の平均ＫＡＭ値をＫtylとした場合に、以下の（３）式及び（４）式～（７）式を満たす。
　Ａｒ３（℃）＝１０２０－３２５×［Ｃ］＋３３×［Ｓｉ］＋２８７×［Ｐ］＋８０×［ｓｏｌ．Ａｌ］－１２０×（［Ｍｎ］＋［Ｍｏ］＋［Ｃｕ］）－４６×（［Ｃｒ］＋［Ｎｉ］）　　　・・・（１）
　Ｍ＝（cosφ×cosλ）-1　　　・・・（２）
　Ｓ411／Ｓ100＞１．００　　　・・・（３）
　０．２０≦Ｓtyl／Ｓtot≦０．８５　　　・・・（４）
　０．０５≦Ｓ411／Ｓtot≦０．８０　　　・・・（５）
　Ｓ411／Ｓtra≧０．５０　　　・・・（６）
　Ｋ411／Ｋtyl≦０．９９０　　　・・・（７）
　ここで、（２）式中のφは応力ベクトルと結晶のすべり方向ベクトルのなす角を表し、λは応力ベクトルと結晶のすべり面の法線ベクトルのなす角を表す。
（３）本開示の一態様に係る無方向性電磁鋼板は、
　質量％で、
　Ｃ　：０．０１００％以下、
　Ｓｉ：１．５０％～４．００％、
　ｓｏｌ．Ａｌ：０．０００１％～１．０％、
　Ｓ　：０．０１００％以下、
　Ｎ　：０．０１００％以下、
　Ｍｎ：０．１０％以上、
　Ｍｎ、Ｎｉ、及びＣｕから選ばれる１種又は複数種：総計で２．５０％未満、
　Ｍｏ：０．０％～２．５％未満、
　Ｃｒ：０．０％～２．５％未満、
　Ｔｉ：０．０００％～０．００５％、
　Ｎｂ：０．０００％～０．００５％、
　Ｓｎ：０．０００％～０．４００％、
　Ｓｂ：０．０００％～０．４００％、
　Ｐ　：０．０００％～０．４００％、及び 
　Ｍｇ、Ｃａ、Ｓｒ、Ｂａ、Ｃｅ、Ｌａ、Ｎｄ、Ｐｒ、Ｚｎ、及びＣｄからなる群から選ばれる１種又は複数種：総計で０．００００％～０．０１００％を含有し、
質量％での、Ｃ含有量を［Ｃ］、Ｍｏ含有量を［Ｍｏ］、Ｃｒ含有量を［Ｃｒ］、Ｍｎ含有量を［Ｍｎ］、Ｎｉ含有量を［Ｎｉ］、Ｃｕ含有量を［Ｃｕ］、Ｓｉ含有量を［Ｓｉ］、ｓｏｌ．Ａｌ含有量を［ｓｏｌ．Ａｌ］、Ｐ含有量を［Ｐ］としたときに、以下の（１）式で定めた変態温度Ａｒ３（℃）が７５０～１０５０℃であり、残部がＦｅおよび不純物からなる化学組成を有し、
　さらに、鋼板表面に平行な面でＥＢＳＤにより観察したときにおいて、全面積をＳtot、｛４１１｝方位粒の面積をＳ411、｛１００｝方位粒の面積をＳ100、以下の（２）式に従うテイラー因子Ｍが２．９超となる方位粒の面積をＳtyl、前記テイラー因子Ｍが２．９以下となる方位粒の合計面積をＳtraとした場合に、以下の（８）式～（１１）式を満たす。
　Ａｒ３（℃）＝１０２０－３２５×［Ｃ］＋３３×［Ｓｉ］＋２８７×［Ｐ］＋８０×［ｓｏｌ．Ａｌ］－１２０×（［Ｍｎ］＋［Ｍｏ］＋［Ｃｕ］）－４６×（［Ｃｒ］＋［Ｎｉ］）　　　・・・（１）
　Ｍ＝（cosφ×cosλ）-1　　　・・・（２）
　Ｓ411／Ｓ100＞２．００　　　・・・（８）
　Ｓtyl／Ｓtot＜０．５５　　　・・・（９）
　Ｓ411／Ｓtot＞０．３０　　　・・・（１０）
　Ｓ411／Ｓtra≧０．６０　　　・・・（１１）
　ここで、（２）式中のφは応力ベクトルと結晶のすべり方向ベクトルのなす角を表し、λは応力ベクトルと結晶のすべり面の法線ベクトルのなす角を表す。
（４）
　質量％で、
　Ｃ　：０．０１００％以下、
　Ｓｉ：１．５０％～４．００％、
　ｓｏｌ．Ａｌ：０．０００１％～１．０％、
　Ｓ　：０．０１００％以下、
　Ｎ　：０．０１００％以下、
　Ｍｎ：０．１０％以上、
　Ｍｎ、Ｎｉ、Ｃｏ、Ｐｔ、Ｐｂ、Ａｕ、及びＣｕから選ばれる１種又は複数種：総計で２．５０％未満、
　Ｍｏ：０．０％～２．５％未満、
　Ｃｒ：０．０％～２．５％未満、
　Ｔｉ：０．０００％～０．００５％、
　Ｎｂ：０．０００％～０．００５％、
　Ｓｎ：０．０００％～０．４００％、
　Ｓｂ：０．０００％～０．４００％、
　Ｐ　：０．０００％～０．４００％、及び
　Ｍｇ、Ｃａ、Ｓｒ、Ｂａ、Ｃｅ、Ｌａ、Ｎｄ、Ｐｒ、Ｚｎ、及びＣｄからなる群から選ばれる１種又は複数種：総計で０．００００％～０．０１００％を含有し、
質量％での、Ｃ含有量を［Ｃ］、Ｍｏ含有量を［Ｍｏ］、Ｃｒ含有量を［Ｃｒ］、Ｍｎ含有量を［Ｍｎ］、Ｎｉ含有量を［Ｎｉ］、Ｃｕ含有量を［Ｃｕ］、Ｓｉ含有量を［Ｓｉ］、ｓｏｌ．Ａｌ含有量を［ｓｏｌ．Ａｌ］、Ｐ含有量を［Ｐ］としたときに、以下の（１）式で定めた変態温度Ａｒ３（℃）が７５０～１０５０℃であり、残部がＦｅおよび不純物からなる化学組成を有し、
　さらに、鋼板表面に平行な面でＥＢＳＤにより観察したときにおいて、全面積をＳtot、｛４１１｝方位粒の面積をＳ411、｛１００｝方位粒の面積をＳ100、以下の（２）式に従うテイラー因子Ｍが２．９超となる方位粒の面積をＳtyl、前記テイラー因子Ｍが２．９以下となる方位粒の合計面積をＳtraとした場合に、以下の（８）式～（１１）式を満たす。
　Ａｒ３（℃）＝１０２０－３２５×［Ｃ］＋３３×［Ｓｉ］＋２８７×［Ｐ］＋８０×［ｓｏｌ．Ａｌ］－１２０×（［Ｍｎ］＋［Ｍｏ］＋［Ｃｕ］）－４６×（［Ｃｒ］＋［Ｎｉ］）　　　・・・（１）
　Ｍ＝（cosφ×cosλ）-1　　　・・・（２）
　Ｓ411／Ｓ100＞２．００　　　・・・（８）
　Ｓtyl／Ｓtot＜０．５５　　　・・・（９）
　Ｓ411／Ｓtot＞０．３０　　　・・・（１０）
　Ｓ411／Ｓtra≧０．６０　　　・・・（１１）
　ここで、（２）式中のφは応力ベクトルと結晶のすべり方向ベクトルのなす角を表し、λは応力ベクトルと結晶のすべり面の法線ベクトルのなす角を表す。 (1) A non-oriented electrical steel sheet according to one embodiment of the present disclosure,
In mass percent,
C: 0.0100% or less,
Si: 1.50% to 4.00%,
sol. Al: 0.0001% to 1.0%,
S: 0.0100% or less,
N: 0.0100% or less,
Mn: 0.10% or more,
One or more selected from Mn, Ni, and Cu: less than 2.50% in total;
Mo: 0.0% to less than 2.5%
Cr: 0.0% to less than 2.5%
Ti: 0.000% to 0.005%,
Nb: 0.000% to 0.005%,
Sn: 0.000% to 0.400%,
Sb: 0.000% to 0.400%,
P: 0.000% to 0.400%, and one or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total;
In mass%, the C content is [C], the Mo content is [Mo], the Cr content is [Cr], the Mn content is [Mn], the Ni content is [Ni], the Cu content is [Cu], and the Si content is [Si].
The alloy has a chemical composition in which the transformation temperature Ar 3 (°C) defined by the following formula (1) is 750 to 1050°C, with the balance being Fe and impurities, where the sol. Al content is [sol. Al] and the P content is [P]:
Furthermore, when observed by EBSD on a plane parallel to the steel sheet surface, the total area is S tot , the area of {411} oriented grains is S 411 , the area of {100} oriented grains is S 100 , the area of oriented grains having a Taylor factor M of more than 2.9 according to the following formula (2) is S tyl , the total area of oriented grains having the Taylor factor M of 2.9 or less is S tra , the average KAM value of the {411} oriented grains is K 411 , and the average KAM value of the oriented grains having the Taylor factor M of more than 2.9 is K tyl , and the following (
Formula (3) and formulas (4) to (7) are satisfied.
Ar 3 (°C)=1020-325×[C]+33×[Si]+287×[P]+80×[sol. Al]-120×([Mn]+[Mo]+[Cu])-46×([Cr]+[Ni])...(1)
M=(cosφ×cosλ) -1 ...(2)
S 411 /S 100 >1.00...(3)
0.20≦S tyl /S tot ≦0.85 (4)
0.05≦S 411 /S tot ≦0.80 (5)
S411 / Stra ≧0.50...(6)
K 411 /K tyl ≦0.990 (7)
Here, in formula (2), φ represents the angle between the stress vector and the slip direction vector of the crystal, and λ represents the angle between the stress vector and the normal vector of the slip plane of the crystal.
(2) A non-oriented electrical steel sheet according to one embodiment of the present disclosure,
In mass percent,
C: 0.0100% or less,
Si: 1.50% to 4.00%,
sol. Al: 0.0001% to 1.0%,
S: 0.0100% or less,
N: 0.0100% or less,
Mn: 0.10% or more,
One or more selected from Mn, Ni, Co, Pt, Pb, Au, and Cu: less than 2.50% in total;
Mo: 0.0% to less than 2.5%
Cr: 0.0% to less than 2.5%
Ti: 0.000% to 0.005%,
Nb: 0.000% to 0.005%,
Sn: 0.000% to 0.400%,
Sb: 0.000% to 0.400%,
P: 0.000% to 0.400%, and one or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total, and when the C content is [C], the Mo content is [Mo], the Cr content is [Cr], the Mn content is [Mn], the Ni content is [Ni], the Cu content is [Cu], the Si content is [Si], the sol. Al content is [sol. Al], and the P content is [P], the transformation temperature Ar 3 (°C) defined by the following formula (1) is 750 to 1050°C, and the balance is Fe and impurities,
Furthermore, when observed by EBSD on a plane parallel to the steel sheet surface, if the total area is S tot , the area of the {411} oriented grains is S 411 , the area of the {100} oriented grains is S 100 , the area of the oriented grains having a Taylor factor M of more than 2.9 according to the following formula (2) is S tyl , the total area of the oriented grains having the Taylor factor M of 2.9 or less is S tra , the average KAM value of the {411} oriented grains is K 411 , and the average KAM value of the oriented grains having the Taylor factor M of more than 2.9 is K tyl , the following formulas (3) and (4) to (7) are satisfied.
Ar 3 (°C)=1020-325×[C]+33×[Si]+287×[P]+80×[sol. Al]-120×([Mn]+[Mo]+[Cu])-46×([Cr]+[Ni])...(1)
M=(cosφ×cosλ) -1 ...(2)
S 411 /S 100 >1.00...(3)
0.20≦S tyl /S tot ≦0.85 (4)
0.05≦S 411 /S tot ≦0.80 (5)
S 411 /S tra ≧0.50 (6)
K 411 /K tyl ≦0.990 (7)
Here, in formula (2), φ represents the angle between the stress vector and the slip direction vector of the crystal, and λ represents the angle between the stress vector and the normal vector of the slip plane of the crystal.
(3) A non-oriented electrical steel sheet according to one embodiment of the present disclosure,
In mass percent,
C: 0.0100% or less,
Si: 1.50% to 4.00%,
sol. Al: 0.0001% to 1.0%,
S: 0.0100% or less,
N: 0.0100% or less,
Mn: 0.10% or more,
One or more selected from Mn, Ni, and Cu: less than 2.50% in total;
Mo: 0.0% to less than 2.5%
Cr: 0.0% to less than 2.5%
Ti: 0.000% to 0.005%,
Nb: 0.000% to 0.005%,
Sn: 0.000% to 0.400%,
Sb: 0.000% to 0.400%,
P: 0.000% to 0.400%, and
One or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total;
The alloy has a chemical composition in which the transformation temperature Ar 3 (°C) defined by the following formula (1) is 750 to 1050°C, with the balance being Fe and impurities, where the C content is [C], the Mo content is [Mo], the Cr content is [ Cr], the Mn content is [Mn], the Ni content is [Ni], the Cu content is [Cu], the Si content is [Si], the sol. Al content is [sol. Al], and the P content is [P], in mass %,
Furthermore, when observed by EBSD on a plane parallel to the steel sheet surface, the following formulas (8) to (11) are satisfied when the total area is S tot , the area of the {411} oriented grains is S 411 , the area of the {100} oriented grains is S 100 , the area of the oriented grains having a Taylor factor M of more than 2.9 according to the following formula (2) is S tyl , and the total area of the oriented grains having a Taylor factor M of 2.9 or less is S tra .
Ar 3 (°C)=1020-325×[C]+33×[Si]+287×[P]+80×[sol. Al]-120×([Mn]+[Mo]+[Cu])-46×([Cr]+[Ni])...(1)
M=(cosφ×cosλ) -1 ...(2)
S 411 /S 100 >2.00...(8)
S tyl /S tot <0.55...(9)
S 411 /S tot >0.30...(10)
S 411 /S tra ≧0.60 (11)
Here, in formula (2), φ represents the angle between the stress vector and the slip direction vector of the crystal, and λ represents the angle between the stress vector and the normal vector of the slip plane of the crystal.
(4)
In mass percent,
C: 0.0100% or less,
Si: 1.50% to 4.00%,
sol. Al: 0.0001% to 1.0%,
S: 0.0100% or less,
N: 0.0100% or less,
Mn: 0.10% or more,
One or more selected from Mn, Ni, Co, Pt, Pb, Au, and Cu: less than 2.50% in total;
Mo: 0.0% to less than 2.5%
Cr: 0.0% to less than 2.5%
Ti: 0.000% to 0.005%,
Nb: 0.000% to 0.005%,
Sn: 0.000% to 0.400%,
Sb: 0.000% to 0.400%,
P: 0.000% to 0.400%, and one or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total;
The alloy has a chemical composition in which the transformation temperature Ar 3 (°C) defined by the following formula (1) is 750 to 1050°C, with the balance being Fe and impurities, where the C content is [C], the Mo content is [Mo], the Cr content is [ Cr], the Mn content is [Mn], the Ni content is [Ni], the Cu content is [Cu], the Si content is [Si], the sol. Al content is [sol. Al], and the P content is [P], in mass %,
Furthermore, when observed by EBSD on a plane parallel to the steel sheet surface, the following formulas (8) to (11) are satisfied when the total area is S tot , the area of the {411} oriented grains is S 411 , the area of the {100} oriented grains is S 100 , the area of the oriented grains having a Taylor factor M of more than 2.9 according to the following formula (2) is S tyl , and the total area of the oriented grains having a Taylor factor M of 2.9 or less is S tra .
Ar 3 (°C)=1020-325×[C]+33×[Si]+287×[P]+80×[sol. Al]-120×([Mn]+[Mo]+[Cu])-46×([Cr]+[Ni])...(1)
M=(cosφ×cosλ) -1 ...(2)
S 411 /S 100 >2.00...(8)
S tyl /S tot <0.55...(9)
S 411 /S tot >0.30...(10)
S 411 /S tra ≧0.60 (11)
Here, in formula (2), φ represents the angle between the stress vector and the slip direction vector of the crystal, and λ represents the angle between the stress vector and the normal vector of the slip plane of the crystal.
　本開示の上記態様によれば、圧延性が問題とならないように、Ｍｎの添加を抑制するとともに、ＣｕおよびＮｉなどの元素の含有量を適正化した化学組成を有する鋼板において、板面内異方性が小さく全周平均（全方向平均）が優れた磁気特性を有する無方向性電磁鋼板を提供することができる。 According to the above-mentioned aspects of the present disclosure, it is possible to provide a non-oriented electrical steel sheet having a chemical composition in which the content of elements such as Cu and Ni is optimized while suppressing the addition of Mn so that rollability is not an issue, and which has small in-plane anisotropy and excellent magnetic properties averaged all around (averaged in all directions).
　本実施形態に係る無方向性電磁鋼板は、後述する化学組成を有する鋼材に対して、熱間圧延工程、冷間圧延工程、中間焼鈍工程、スキンパス圧延工程を施して製造される。
　また、本開示の別の実施形態に係る無方向性電磁鋼板は、後述する化学組成を有する鋼材に対して、冷間圧延工程、中間焼鈍工程、スキンパス圧延工程、最終焼鈍工程を施して製造される。
　本実施形態に係る無方向性電磁鋼板は、Ｍｎの添加量を低限し圧延性を確保し、更に成分調整を行った上で、熱間圧延条件を最適化し熱延板の段階で適切なα加工粒組織を形成することによって、その後の冷延、中間焼鈍で｛４１１｝方位粒が発達する。歪誘起粒成長が起こる前の段階で、｛１００｝方位粒よりも｛４１１｝方位粒を多くすることにより、歪誘起粒成長によって主として｛４１１｝方位粒が｛１１１｝方位粒を蚕食すると同時に｛１００｝方位粒の発達を抑制し、｛４１１｝方位が主方位の無方向性電磁鋼板が製造される。
　スキンパス圧延後の最終焼鈍により、鋼板は歪誘起粒成長及び／または正常粒成長をする。
　そして、｛１００｝方位の発達を十分に抑制した上で、｛４１１｝方位粒を富化させることが、磁気特性の板面内異方性の低減および全周平均（全方向平均）の改善に有効である。 The non-oriented electrical steel sheet according to this embodiment is manufactured by subjecting a steel material having a chemical composition described below to a hot rolling process, a cold rolling process, an intermediate annealing process, and a skin pass rolling process.
Furthermore, a non-oriented electrical steel sheet according to another embodiment of the present disclosure is manufactured by subjecting a steel material having a chemical composition described below to a cold rolling process, an intermediate annealing process, a skin pass rolling process, and a final annealing process.
In the non-oriented electrical steel sheet according to the present embodiment, the amount of Mn added is kept low to ensure rollability, and further, the components are adjusted, and then the hot rolling conditions are optimized to form an appropriate α-processed grain structure at the hot-rolled sheet stage, so that {411} oriented grains develop during the subsequent cold rolling and intermediate annealing. By making the number of {411} oriented grains greater than the {100} oriented grains at a stage before strain-induced grain growth occurs, the {411} oriented grains mainly encroach on the {111} oriented grains due to strain-induced grain growth, while at the same time suppressing the development of the {100} oriented grains, thereby producing a non-oriented electrical steel sheet with the {411} oriented grain as the main orientation.
The final annealing after skin pass rolling causes the steel sheet to undergo strain induced grain growth and/or normal grain growth.
Furthermore, sufficiently suppressing the development of the {100} orientation while enriching the {411} orientation grains is effective in reducing the in-plane anisotropy of the magnetic properties and improving the circumferential average (all-directional average).
　なお、スキンパス圧延後の鋼板は、歪誘起粒成長及び正常粒成長後の鋼板の原板という関係にある。以下、最終焼鈍前後を問わず、スキンパス圧延後の鋼板、歪誘起粒成長及び正常粒成長後の鋼板は、いずれも無方向性電磁鋼板として説明する。 The steel sheet after skin-pass rolling is the original sheet for the steel sheet after strain-induced grain growth and normal grain growth. Hereinafter, regardless of whether it is before or after final annealing, the steel sheet after skin-pass rolling and the steel sheet after strain-induced grain growth and normal grain growth will all be described as non-oriented electrical steel sheet.
　また、本実施形態に係る無方向性電磁鋼板では、スキンパス圧延前の鋼板の金属組織において、｛１００｝方位粒よりも｛４１１｝方位を中心とした結晶粒（以下、｛４１１｝方位粒）を多くすることで、その後のスキンパス圧延および最終焼鈍で｛４１１｝方位粒をより増やし、全周の磁気特性を向上させる。上記記載のプロセス以外でスキンパス圧延前に｛４１１｝方位粒を増やしても良い。 In addition, in the non-oriented electrical steel sheet according to this embodiment, by increasing the number of crystal grains centered on the {411} orientation (hereinafter, {411} orientation grains) compared to the {100} orientation grains in the metal structure of the steel sheet before skin-pass rolling, the number of {411} orientation grains is further increased in the subsequent skin-pass rolling and final annealing, improving the magnetic properties all around. The number of {411} orientation grains may be increased before skin-pass rolling in a process other than that described above.
　まず、本実施形態に係る無方向性電磁鋼板及びその製造方法で用いられる素材である方向性電磁鋼板の化学組成について説明する。圧延や熱処理で化学組成は変化しないので、素材となる方向性電磁鋼板の化学組成と、各工程を経て得られる無方向性鋼板の化学組成は同じである。以下の説明において、無方向性電磁鋼板又は鋼材に含まれる各元素の含有量の単位である「％」は、特に断りがない限り「質量％」を意味する。 First, we will explain the chemical composition of the non-oriented electrical steel sheet according to this embodiment and the oriented electrical steel sheet that is the raw material used in the manufacturing method thereof. The chemical composition does not change due to rolling or heat treatment, so the chemical composition of the raw material oriented electrical steel sheet is the same as the chemical composition of the non-oriented steel sheet obtained through each process. In the following explanation, "%", which is the unit of content of each element contained in the non-oriented electrical steel sheet or steel material, means "mass %" unless otherwise specified.
　なお、本明細書中において、「～」を用いて表される数値範囲は、「～」の前後に記載される数値を下限値及び上限値として含む範囲を意味する。また、以下の実施形態の各要素は、それぞれの組み合わせが可能であることは自明である。
　また、本開示の実施形態において「無方向性電磁鋼板」とは、コイル状または切板状の鋼板はもちろん、モータコアなどの製品（部材）の素材として特定形状に加工された鋼板、さらに加工後に積層されモータコアを構成している鋼板も含む。 In this specification, a numerical range expressed using "to" means a range including the numerical values before and after "to" as the lower and upper limits. It is obvious that each element of the following embodiment can be combined with each other.
In addition, in the embodiments of the present disclosure, "non-oriented electrical steel sheet" includes not only coil-shaped or cut-plate steel sheet, but also steel sheet processed into a specific shape as a material for products (components) such as motor cores, and further steel sheet laminated after processing to form motor cores.
　まず、本開示の実施形態に係る無方向性電磁鋼板及びその製造方法で用いられる鋼材の化学組成について説明する。以下の説明において、無方向性電磁鋼板又は鋼材に含まれる各元素の含有量の単位である「％」は、特に断りがない限り「質量％」を意味する。また、無方向性電磁鋼板の化学組成は、皮膜等を除いた母材を１００％とした場合の含有量を示す。
　また、本明細書中に段階的に記載されている数値範囲において、ある段階的な数値範囲の上限値は、他の段階的な記載の数値範囲の上限値に置き換えてもよく、また、実施例に示されている値に置き換えてもよい。
　本明細書中に段階的に記載されている数値範囲において、ある段階的な数値範囲の下限値は、他の段階的な記載の数値範囲の下限値に置き換えてもよく、また、実施例に示されている値に置き換えてもよい。 First, the chemical composition of the non-oriented electrical steel sheet according to the embodiment of the present disclosure and the steel material used in the manufacturing method thereof will be described. In the following description, the unit of content of each element contained in the non-oriented electrical steel sheet or steel material, "%", means "mass %" unless otherwise specified. Furthermore, the chemical composition of the non-oriented electrical steel sheet indicates the content when the base material excluding the coating, etc. is taken as 100%.
In addition, in the numerical ranges described in stages in this specification, the upper limit value of a certain numerical range may be replaced by the upper limit value of another numerical range described in stages, or may be replaced by a value shown in the examples.
In the numerical ranges described in stages in this specification, the lower limit value of a certain numerical range may be replaced by the lower limit value of another numerical range described in stages, or may be replaced by a value shown in the examples.
　本実施形態に係る無方向性電磁鋼板は、フェライト－オーステナイト変態（以下、α－γ変態）が生じ得る化学組成であって、
　質量％で、
　Ｃ　：０．０１００％以下、
　Ｓｉ：１．５０％～４．００％、
　ｓｏｌ．Ａｌ：０．０００１％～１．０％、
　Ｓ　：０．０１００％以下、
　Ｎ　：０．０１００％以下、
　Ｍｎ：０．１０％以上、
　Ｍｎ、Ｎｉ、及びＣｕから選ばれる１種又は複数種：総計で２．５０％未満、
　Ｍｏ：０．０％～２．５％未満
　Ｃｒ：０．０％～２．５％未満
　Ｔｉ：０．０００％～０．００５％
　Ｎｂ：０．０００％～０．００５％
　Ｓｎ：０．０００％～０．４００％、
　Ｓｂ：０．０００％～０．４００％、
　Ｐ　：０．０００％～０．４００％、及び
　Ｍｇ、Ｃａ、Ｓｒ、Ｂａ、Ｃｅ、Ｌａ、Ｎｄ、Ｐｒ、Ｚｎ、及びＣｄからなる群から選ばれる１種又は複数種：総計で０．００００％～０．０１００％を含有し、さらに、Ｃ、Ｓｉ、Ｐ、ｓｏｌ．Ａｌ、Ｍｎ、Ｍｏ、Ｃｕ、ＣｒおよびＮｉの含有量が後述する所定の条件を満たし、残部がＦｅおよび不純物からなる化学組成を有する。 The non-oriented electrical steel sheet according to this embodiment has a chemical composition in which ferrite-austenite transformation (hereinafter, α-γ transformation) can occur,
In mass percent,
C: 0.0100% or less,
Si: 1.50% to 4.00%,
sol. Al: 0.0001% to 1.0%,
S: 0.0100% or less,
N: 0.0100% or less,
Mn: 0.10% or more,
One or more selected from Mn, Ni, and Cu: less than 2.50% in total;
Mo: 0.0% to less than 2.5% Cr: 0.0% to less than 2.5% Ti: 0.000% to 0.005%
Nb: 0.000% to 0.005%
Sn: 0.000% to 0.400%,
Sb: 0.000% to 0.400%,
P: 0.000% to 0.400%, and one or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total, and further, the contents of C, Si, P, sol. Al, Mn, Mo, Cu, Cr, and Ni satisfy the specified conditions described later, with the balance being Fe and impurities.
　本実施形態に係る無方向性電磁鋼板において、Ｍｎ、Ｎｉ、Ｃｏ、Ｐｔ、Ｐｂ、Ａｕ、及びＣｕから選ばれる１種又は複数種は、総計で２．５０％未満含有することが好ましい。 In the non-oriented electrical steel sheet according to this embodiment, it is preferable that one or more elements selected from Mn, Ni, Co, Pt, Pb, Au, and Cu are contained in a total amount of less than 2.50%.
　不純物としては、鉱石やスクラップ等の原材料に含まれるもの、製造工程において含まれるもの、が例示される。 Examples of impurities include those contained in raw materials such as ores and scraps, and those contained during the manufacturing process.
　（Ｃ：０．０１００％以下）
　Ｃは、鉄損を高めたり、磁気時効を引き起こしたりする。従って、Ｃ含有量は低ければ低いほどよい。このような現象は、Ｃ含有量が０．０１００％超で顕著である。このため、Ｃ含有量は０．０１００％以下とする。Ｃ含有量の低減は、板面内の全方向における磁気特性の均一な向上にも寄与する。なお、Ｃ含有量の下限は特に限定しないが、精錬時の脱炭処理のコストを踏まえ、０．０００５％以上とすることが好ましい。 (C: 0.0100% or less)
C increases iron loss and causes magnetic aging. Therefore, the lower the C content, the better. This phenomenon is significant when the C content exceeds 0.0100%. The C content is set to 0.0100% or less. The reduction in the C content contributes to the uniform improvement of the magnetic properties in all directions in the sheet surface. There is no particular lower limit for the C content, but Taking into consideration the cost of decarburization treatment during refining, the content is preferably 0.0005% or more.
　（Ｓｉ：１．５０％～４．００％）
　Ｓｉは、電気抵抗を増大させて、渦電流損を減少させ、鉄損を低減したり、降伏比を増大させて、鉄心への打ち抜き加工性を向上したりする。Ｓｉ含有量が１．５０％未満では、これらの作用効果を十分に得られない。従って、Ｓｉ含有量は１．５０％以上とする。一方、Ｓｉ含有量が４．００％超では、磁束密度が低下したり、硬度の過度な上昇により打ち抜き加工性が低下したり、冷間圧延が困難になったりする。従って、Ｓｉ含有量は４．００％以下とする。 (Si: 1.50% to 4.00%)
Silicon increases electrical resistance, reduces eddy current loss, reduces iron loss, increases the yield ratio, and improves punching workability into iron cores. If the Si content is less than 5.0%, these effects cannot be sufficiently 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 and the hardness decreases. An excessive increase in Si content reduces punching workability and makes cold rolling difficult. Therefore, the Si content is set to 4.00% or less.
　（ｓｏｌ．Ａｌ：０．０００１％～１．０％）
　ｓｏｌ．Ａｌは、電気抵抗を増大させて、渦電流損を減少させ、鉄損を低減する。ｓｏｌ．Ａｌは、飽和磁束密度に対する磁束密度Ｂ５０の相対的な大きさの向上にも寄与する。ｓｏｌ．Ａｌ含有量が０．０００１％未満では、これらの作用効果を十分に得られない。また、Ａｌには製鋼での脱硫促進効果もある。従って、ｓｏｌ．Ａｌ含有量は０．０００１％以上とする。一方、ｓｏｌ．Ａｌ含有量が１．０％超では、磁束密度が低下したり、降伏比を低下させて、打ち抜き加工性を低下させたりする。従って、ｓｏｌ．Ａｌ含有量は１．０％以下とする。
　なお、ｓｏｌ．Ａｌとは、Ａｌ２Ｏ３等の酸化物になっておらず、酸に可溶する酸可溶Ａｌを意味する。 (sol.Al: 0.0001% to 1.0%)
Sol. Al increases electrical resistance, reduces eddy current loss, and reduces iron loss. Sol. Al also contributes to improving the relative magnitude of magnetic flux density B50 with respect to saturation magnetic flux density. If the sol. Al content is less than 0.0001%, these functions and effects cannot be fully obtained. Furthermore, Al also has the effect of promoting desulfurization in steelmaking. Therefore, the sol. Al content is set to 0.0001% or less. On the other hand, if the sol. Al content exceeds 1.0%, the magnetic flux density decreases, the yield ratio decreases, and punching workability decreases. shall be 1.0% or less.
Incidentally, sol. Al means acid-soluble Al that is not in the form of an oxide such as Al 2 O 3 and is soluble in acid.
　ここで、磁束密度Ｂ５０とは、５０００Ａ／ｍの磁場における磁束密度である。 Here, the magnetic flux density B50 is the magnetic flux density in a magnetic field of 5000 A/m.
　（Ｓ：０．０１００％以下）
　Ｓは、必須元素ではなく、例えば鋼中に不純物として含有される。Ｓは、微細なＭｎＳの析出により、焼鈍における再結晶及び結晶粒の成長を阻害する。従って、Ｓ含有量は低ければ低いほどよい。このような再結晶及び結晶粒成長の阻害による鉄損の増加および磁束密度の低下は、Ｓ含有量が０．０１００％超で顕著である。このため、Ｓ含有量は０．０１００％以下とする。なお、Ｓ含有量の下限は特に限定しないが、精錬時の脱硫処理のコストを踏まえ、０．０００３％以上とすることが好ましい。 (S: 0.0100% or less)
S is not an essential element and is contained, for example, as an impurity in steel. S inhibits recrystallization and grain growth during annealing by precipitating fine MnS. Therefore, the lower the S content, the lower the Such an increase in core loss and a decrease in magnetic flux density due to the inhibition of recrystallization and grain growth are remarkable when the S content exceeds 0.0100%. For this reason, the S content is set to 0.0100 Although there is no particular lower limit for the S content, it is preferable to set the S content to 0.0003% or more in consideration of the cost of desulfurization treatment during refining.
　（Ｎ：０．０１００％以下）
　ＮはＣと同様に、磁気特性を劣化させるので、Ｎ含有量は低ければ低いほどよい。したがって、Ｎ含有量は０．０１００％以下とする。なお、Ｎ含有量の下限は特に限定しないが、精錬時の脱窒処理のコストを踏まえ、０．００１０％以上とすることが好ましい。 (N: 0.0100% or less)
Like C, N deteriorates the magnetic properties, so the lower the N content, the better. Therefore, the N content is set to 0.0100% or less. There is no particular lower limit for the N content, Taking into consideration the cost of denitrification treatment during refining, it is preferable that the Nitrogen content be 0.0010% or more.
　（Ｍｎ、Ｎｉ、及びＣｕから選ばれる１種又は複数種：総計で２．５０％未満）
　Ｍｎ、Ｎｉ、及びＣｕが総計で２．５％以上含有すると磁気特性の異方性が大きくなることから、Ｍｎ、Ｎｉ、及びＣｕの総計は２．５％未満とする。異方性が大きくなる要因は明確ではないが、フェライト域での滑り変形に影響を及ぼし、｛１００｝方位の形成、再結晶を促すためと考えられる。また、合金元素の含有量の増加は、この観点から２．３％以下とすることが好ましい。Ｍｎ、Ｎｉ、及びＣｕの総計の下限値は特に制限されないが、例えば０．１０％以上としてもよく、０．５０％以上、もしくは、１．００％以上、さらに、２．００％以上としてもよい。 (One or more selected from Mn, Ni, and Cu: less than 2.50% in total)
When the total content of Mn, Ni, and Cu is 2.5% or more, the anisotropy of the magnetic properties increases, so the total content of Mn, Ni, and Cu is less than 2.5%. The reason why the anisotropy increases is not clear, but it is thought to be because it affects the slip deformation in the ferrite region and promotes the formation of the {100} orientation and recrystallization. From this point of view, it is preferable that the increase in the content of the alloying elements is 2.3% or less. The lower limit of the total content of Mn, Ni, and Cu is not particularly limited, but may be, for example, 0.10% or more, 0.50% or more, 1.00% or more, or even 2.00% or more.
　（Ｍｎ、Ｎｉ、Ｃｏ、Ｐｔ、Ｐｂ、Ａｕ、及びＣｕから選ばれる１種又は複数種：総計で２．５０％未満）
　上述のＭｎ、Ｎｉ、及びＣｕに加えて、Ｃｏ、Ｐｔ、Ｐｂ、及びＡｕも磁気特性の異方性を大きくすることから、本実施形態ではこれらの元素の含有量を総計で２．５０％未満にとどめることが好ましい。また、これらの元素は磁束密度を低下させるため、総計で２．００％未満とすることが好ましい。Ｍｎ、Ｎｉ、Ｃｏ、Ｐｔ、Ｐｂ、Ａｕ、及びＣｕの総計の下限値は特に制限されないが、例えば０．１０％以上としてもよく、０．５０％以上、もしくは、１．００％以上、さらに、２．００％以上としてもよい。特にＣｏ、Ｐｔ、Ｐｂ、及びＡｕは合金コストが高いことから、積極的な添加は回避すべきである。また、本実施形態の特徴の一つであるＡｒ３変態点の制御を考慮しても、Ｍｎ、Ｎｉ、及びＣｕの含有によりＡｒ３変態点を制御することが好ましい。このため、Ｃｏ、Ｐｔ、Ｐｂ、及びＡｕの総計は０．５％未満、さらに好ましくは０．１％以下、さらには不可避元素の範囲内での混入に留め、積極的な添加をあえて実施する必要はない（０％としてもよい。）。 (One or more selected from Mn, Ni, Co, Pt, Pb, Au, and Cu: less than 2.50% in total)
In addition to the above-mentioned Mn, Ni, and Cu, Co, Pt, Pb, and Au also increase the anisotropy of the magnetic properties, so in this embodiment, it is preferable to keep the content of these elements less than 2.50% in total. Furthermore, since these elements reduce the magnetic flux density, it is preferable to keep the content of these elements less than 2.00% in total. The lower limit of the total of Mn, Ni, Co, Pt, Pb, Au, and Cu is not particularly limited, but may be, for example, 0.10% or more, 0.50% or more, or 1.00% or more, or even 2.00% or more. In particular, since the alloy cost of Co, Pt, Pb, and Au is high, active addition should be avoided. Furthermore, even considering the control of the Ar 3 transformation point, which is one of the features of this embodiment, it is preferable to control the Ar 3 transformation point by containing Mn, Ni, and Cu. For this reason, the total amount of Co, Pt, Pb, and Au should be less than 0.5%, more preferably 0.1% or less, and should be kept within the range of unavoidable elements, and there is no need to actively add them (it may be 0%).
　また、本実施形態に係る無方向性電磁鋼板及び鋼材は、α－γ変態が生じ得る条件として、さらに以下の条件を満たしているものとする。つまり、質量％での、Ｃ含有量を［Ｃ］、Ｍｏ含有量を［Ｍｏ］、Ｃｒ含有量を［Ｃｒ］、Ｍｎ含有量を［Ｍｎ］、Ｎｉ含有量を［Ｎｉ］、Ｃｕ含有量を［Ｃｕ］、Ｓｉ含有量を［Ｓｉ］、ｓｏｌ．Ａｌ含有量を［ｓｏｌ．Ａｌ］、Ｐ含有量を［Ｐ］としたときに、以下の（１）式で定めた変態温度Ａｒ３（℃）が７５０～１０５０℃であることを満たすものとする。 Furthermore, the non-oriented electrical steel sheet and steel material according to this embodiment further satisfy the following condition as a condition under which α-γ transformation can occur: In other words, when the C content is [C], the Mo content is [Mo], the Cr content is [Cr], the Mn content is [Mn], the Ni content is [Ni], the Cu content is [Cu], the Si content is [Si], the sol. Al content is [sol. Al], and the P content is [P], in mass%, the transformation temperature Ar 3 (°C) defined by the following formula (1) is 750 to 1050°C.
　Ａｒ３（℃）＝１０２０－３２５×［Ｃ］＋３３×［Ｓｉ］＋２８７×［Ｐ］＋８０×［ｓｏｌ．Ａｌ］－１２０×（［Ｍｎ］＋［Ｍｏ］＋［Ｃｕ］）－４６×（［Ｃｒ］＋［Ｎｉ］）　　　・・・（１） Ar 3 (°C)=1020-325×[C]+33×[Si]+287×[P]+80×[sol. Al]-120×([Mn]+[Mo]+[Cu])-46×([Cr]+[Ni])...(1)
　前述の（１）式を満たさない場合には、α－γ変態が生じたとしても変態点が適切な温度範囲にないため、後述の製造方法を適用しても、十分な磁束密度が得られない。Ａｒ３変態点が７５０℃未満となると熱間圧延の温度が低温化するために変形抵抗が高くなり圧延機への負荷が大きくなりすぎるとともに、元素の添加量が高くなるために熱延板および冷延板の靭性低下にもつながることからこの値を下限とする。一方、Ａｒ３変態点が１０５０℃超となると熱間圧延温度が高くなりすぎるために極めて高温加熱が必要となり加熱炉への負荷が高くなる、またはγ→α変態が起こらない成分系になってくるためこの値を上限とする。 If the above formula (1) is not satisfied, even if α-γ transformation occurs, the transformation point is not in an appropriate temperature range, so sufficient magnetic flux density cannot be obtained even if the manufacturing method described below is applied. If the Ar3 transformation point is less than 750 ° C, the hot rolling temperature is lowered, so the deformation resistance increases and the load on the rolling mill becomes too large, and the amount of added elements increases, which leads to a decrease in toughness of the hot-rolled sheet and the cold-rolled sheet, so this value is set as the lower limit. On the other hand, if the Ar3 transformation point exceeds 1050 ° C, the hot rolling temperature becomes too high, so extremely high temperature heating is required, which increases the load on the heating furnace, or the component system does not cause γ → α transformation, so this value is set as the upper limit.
　（Ｍｎ：０．１０％以上）
　Ｍｎは、Ａｒ３変態点を低下させ、本実施形態に係る無方向性電磁鋼板の成分系において、相変態による熱延板の結晶粒の微細化を可能とする。Ｍｎは鋼の電気抵抗を高め、鉄損を低減する元素である。そのため、Ｍｎは０．１％以上含有させる。この観点からはＭｎは０．５％以上含有させることが好ましい。更に好ましくは１．０％以上である。一方、Ｍｎは偏析しやすい元素であり、含有量が増えると、偏析起因の冷間加工割れを起こすだけでなく、飽和磁束密度を低下させ鋼板の磁束密度の上昇を妨げる。また、ＭｎＳが過剰に生成して、冷間加工性が低下する。そのため、Ｍｎ含有量の上限は２．５％未満とする。Ｍｎ含有量の上限は、２．３質量％以下が好ましく、２.０質量％がより好ましい。 (Mn: 0.10% or more)
Mn lowers the Ar3 transformation point, and in the component system of the non-oriented electrical steel sheet according to this embodiment, it is possible to refine the crystal grains of the hot-rolled sheet by phase transformation. Mn is an element that increases the electrical resistance of steel and reduces iron loss. Therefore, Mn is contained at 0.1% or more. From this viewpoint, Mn is preferably contained at 0.5% or more. More preferably, it is contained at 1.0% or more. On the other hand, Mn is an element that is prone to segregation, and if the content increases, not only does it cause cold work cracks due to segregation, but it also reduces the saturation magnetic flux density and prevents the increase in the magnetic flux density of the steel sheet. In addition, MnS is generated excessively, and the cold workability is reduced. Therefore, the upper limit of the Mn content is less than 2.5%. The upper limit of the Mn content is preferably 2.3 mass% or less, and more preferably 2.0 mass%.
（Ｃｕ：上記各元素との総計で２．５％未満）
　ＣｕはＭｎと同様に鋼板の電気抵抗を高め、鉄損を低減する元素であり、Ａｒ３変態点を低下させて本実施形態に係る無方向性電磁鋼板の化学組成において、相変態による熱延板粒径の微細化を可能とする元素である。しかしながら、Ｃｕ含有量が高くとなると再結晶温度の上昇などにより冷延以降の焼鈍における集合組織形成に悪影響をおよぼすとともに熱間での脆化の原因となるだけでなく、飽和磁束密度を低下させ鋼板の磁束密度の上昇を妨げることから注意を要する。なお、Ｃｕ含有量の半量以上のＮｉを複合添加とすることでＣｕに起因する熱間での脆化を軽減できる。Ｃｕ含有量の上限は限定されないが、２．５％未満とする。また、Ｃｕ含有量の上限は１．５質量％以下が好ましく、１．０質量％以下がより好ましい。Ｃｕ含有量の下限は特に制限されないが、例えば０．０１％以上とすればよい。 (Cu: less than 2.5% in total with the above elements)
Cu is an element that increases the electrical resistance of the steel sheet and reduces iron loss, similar to Mn, and reduces the Ar3 transformation point, enabling the fineness of the hot-rolled sheet grain size by phase transformation in the chemical composition of the non-oriented electrical steel sheet according to this embodiment. However, if the Cu content is high, it not only adversely affects the formation of texture in annealing after cold rolling due to an increase in recrystallization temperature, and causes embrittlement in the hot state, but also reduces the saturation magnetic flux density and prevents the increase in the magnetic flux density of the steel sheet, so caution is required. In addition, by adding Ni in an amount equal to or more than half the Cu content, embrittlement in the hot state caused by Cu can be reduced. The upper limit of the Cu content is not limited, but is less than 2.5%. In addition, the upper limit of the Cu content is preferably 1.5 mass% or less, and more preferably 1.0 mass% or less. The lower limit of the Cu content is not particularly limited, but may be, for example, 0.01% or more.
（Ｎｉ：上記各元素との総計で２．５％未満）
　ＮｉはＭｎと同様に鋼板の電気抵抗を高め、鉄損を低減する。Ｎｉはさらに、Ａ３変態点を低下させて本実施形態に係る無方向性電磁鋼板の化学組成において、相変態による結晶粒の微細化を可能とする。しかしながら、Ｎｉ含有量が高すぎれば、Ｎｉは高価であるため製品コストが高くなるだけでなく、飽和磁束密度を低下させ鋼板の磁束密度の上昇を妨げるため、含有量の設計においてはこれらを考慮することが好ましい。Ｎｉ含有量の上限は限定されないが、２．５％未満とする。また、Ｎｉ含有量の上限は、１．０質量％以下が好ましく、０．７質量％以下がより好ましい。Ｎｉ含有量の下限は特に制限されないが、例えば０．０１％以上としてもよい。 (Ni: less than 2.5% in total with the above elements)
Ni, like Mn, increases the electrical resistance of the steel sheet and reduces iron loss. Ni further lowers the A3 transformation point, enabling the crystal grains to be refined by phase transformation in the chemical composition of the non-oriented electrical steel sheet according to this embodiment. However, if the Ni content is too high, not only will the product cost increase because Ni is expensive, but it will also reduce the saturation magnetic flux density and prevent the magnetic flux density of the steel sheet from increasing, so it is preferable to take these factors into consideration when designing the content. The upper limit of the Ni content is not limited, but is less than 2.5%. In addition, the upper limit of the Ni content is preferably 1.0 mass% or less, and more preferably 0.7 mass% or less. The lower limit of the Ni content is not particularly limited, but may be, for example, 0.01% or more.
（Ｍｏ：０．０％～２．５％未満）
　ＭｏはＡｒ３変態点を低下させ本実施形態に係る無方向性電磁鋼板の化学組成において、相変態による熱延板粒径の微細化を可能とする元素である。したがって、Ｍｏは必要に応じて含有させてもよく０．１％以上含有することが好ましい。一方で、Ｍｏを２．５％以上含有することは冷間加工性を著しく低下させることから、Ｍｏ含有量は２．５％未満とする。 (Mo: 0.0% to less than 2.5%)
Mo is an element that lowers the Ar3 transformation point and enables the refinement of the grain size of the hot-rolled sheet by phase transformation in the chemical composition of the non-oriented electrical steel sheet according to this embodiment. Therefore, Mo may be contained as necessary, and it is preferable to contain 0.1% or more. On the other hand, since the inclusion of 2.5% or more of Mo significantly reduces the cold workability, the Mo content is set to less than 2.5%.
（Ｃｒ：０．０％～２．５％未満）
　ＣｒはＡｒ３変態点を低下させ本実施形態に係る無方向性電磁鋼板の化学組成において、相変態による熱延板粒径の微細化を可能とする元素であると共に、強度調整や耐食性の他、特に高周波特性を向上させる効果がある。したがって、Ｃｒは必要に応じて含有させてもよく、０．１％以上含有することが好ましい。一方で、Ｃｒの過剰な含有は効果が飽和し原料コストを増加させるだけでなく、飽和磁束密度を低下させ鋼板の磁束密度の上昇を妨げる。このため、Ｃｒ含有量は、２.５％未満とする。 (Cr: 0.0% to less than 2.5%)
Cr is an element that lowers the Ar3 transformation point and enables the refinement of the grain size of the hot-rolled sheet by phase transformation in the chemical composition of the non-oriented electrical steel sheet according to this embodiment, and has the effect of improving not only strength adjustment and corrosion resistance, but also high-frequency characteristics in particular. Therefore, Cr may be contained as necessary, and it is preferable to contain 0.1% or more. On the other hand, excessive Cr content not only saturates the effect and increases the raw material cost, but also reduces the saturation magnetic flux density and prevents the magnetic flux density of the steel sheet from increasing. For this reason, the Cr content is set to less than 2.5%.
（Ｔｉ：０．０００％～０．００５％）
　Ｔｉは固溶、またはＴｉＮとして存在することで再結晶が抑制されオーステナイト粒径の微細化に寄与する。したがって、Ｔｉは必要に応じて含有させてもよく、０．００１％以上含有することが好ましい。一方、Ｔｉ含有量が０．００５％を超えると、ＴｉＮ、ＴｉＳ，およびＴｉＣなど様々な析出物を生成し、鉄損特性を劣化させることから、０．００５％以下とする。 (Ti: 0.000% to 0.005%)
Ti, when present in the form of a solid solution or TiN, suppresses recrystallization and contributes to refinement of the austenite grain size. Therefore, Ti may be added as necessary, and it is recommended that Ti content be 0.001% or more. On the other hand, if the Ti content exceeds 0.005%, various precipitates such as TiN, TiS, and TiC are formed, which deteriorates the core loss characteristics, so the Ti content is set to 0.005% or less.
（Ｎｂ：０．０００％～０．００５％）
　Ｎｂは固溶、またはＮｂＮとして存在することで再結晶が抑制されオーステナイト粒径の微細化に寄与する。したがって、Ｎｂは必要に応じて含有させてもよく、０．００１％以上含有することが好ましい。一方、Ｎｂ含有量が０．００５％を超えると、ＮｂＮおよびＮｂＣなど様々な析出物を生成し、鉄損特性を劣化させることから、０．００５％以下とする。 (Nb: 0.000% to 0.005%)
Nb, when present in the form of a solid solution or NbN, suppresses recrystallization and contributes to refinement of the austenite grain size. Therefore, Nb may be added as necessary, and it is recommended that Nb be added in an amount of 0.001% or more. On the other hand, if the Nb content exceeds 0.005%, various precipitates such as NbN and NbC are generated and the core loss characteristics are deteriorated, so the Nb content is set to 0.005% or less.
　（Ｓｎ：０．０００％～０．４００％、Ｓｂ：０．０００％～０．４００％、Ｐ：０．０００％～０．４００％）
　ＳｎやＳｂは冷間圧延、再結晶後の集合組織を改善して、その磁束密度を向上させる。そのため、これらの元素を必要に応じて含有させてもよいが、過剰に含まれると鋼を脆化させる。したがって、Ｓｎ含有量、Ｓｂ含有量はいずれも０．４００％以下とする。また、Ｐは再結晶後の鋼板の硬度を確保するために含有させてもよいが、過剰に含まれると鋼の脆化を招く。したがって、Ｐ含有量は０．４００％以下とする。 (Sn: 0.000% to 0.400%, Sb: 0.000% to 0.400%, P: 0.000% to 0.400%)
Sn and Sb improve the texture after cold rolling and recrystallization, and increase the magnetic flux density. Therefore, these elements may be added as necessary, but if they are included in excess, the steel may become Therefore, the Sn content and the Sb content are both set to 0.400% or less. P may be added to ensure the hardness of the steel sheet after recrystallization, but excessive P should not be added. Therefore, the P content is set to 0.400% or less.
　磁気特性等のさらなる効果を付与する場合には、０．０２０％～０．４００％のＳｎ、０．０２０％～０．４００％のＳｂ、及び０．０２０％～０．４００％のＰからなる群から選ばれる１種又は複数種を含有することが好ましい。 If additional effects such as magnetic properties are to be imparted, it is preferable to contain one or more elements selected from the group consisting of 0.020% to 0.400% Sn, 0.020% to 0.400% Sb, and 0.020% to 0.400% P.
　（Ｍｇ、Ｃａ、Ｓｒ、Ｂａ、Ｃｅ、Ｌａ、Ｎｄ、Ｐｒ、Ｚｎ、及びＣｄからなる群から選ばれる１種又は複数種：総計で０．００００％～０．０１００％）
　Ｍｇ、Ｃａ、Ｓｒ、Ｂａ、Ｃｅ、Ｌａ、Ｎｄ、Ｐｒ、Ｚｎ及びＣｄは、溶鋼の鋳造時に溶鋼中のＳと反応して硫化物若しくは酸硫化物又はこれらの両方の析出物を生成する。以下、Ｍｇ、Ｃａ、Ｓｒ、Ｂａ、Ｃｅ、Ｌａ、Ｎｄ、Ｐｒ、Ｚｎ及びＣｄを総称して「粗大析出物生成元素」ということがある。粗大析出物生成元素の析出物の粒径は１μｍ～２μｍ程度であり、ＭｎＳ、ＴｉＮ、ＡｌＮ、ＴｉＣ、ＮｂＣ等の微細析出物の粒径（１００ｎｍ程度）よりはるかに大きい。このため、これら微細析出物は粗大析出物生成元素の析出物に付着し、中間焼鈍などの焼鈍における再結晶及び結晶粒の成長を阻害しにくくなる。これらの作用効果を十分に得るためには、粗大析出物生成元素の総計が０．０００５％以上であることが好ましい。但し、これらの元素の総計が０．０１００％を超えると、硫化物若しくは酸硫化物又はこれらの両方の総量が過剰となり、中間焼鈍などの焼鈍における再結晶及び結晶粒の成長が阻害される。従って、粗大析出物生成元素の含有量は総計で０．０１００％以下とする。 (One or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total)
Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn and Cd react with S in the molten steel during casting of the molten steel to form precipitates of sulfides or oxysulfides, or both. Hereinafter, Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn and Cd may be collectively referred to as "coarse precipitate forming elements". The particle size of the precipitates of the coarse precipitate forming elements is about 1 μm to 2 μm, which is much larger than the particle size (about 100 nm) of fine precipitates such as MnS, TiN, AlN, TiC, and NbC. For this reason, these fine precipitates adhere to the precipitates of the coarse precipitate forming elements, and are less likely to inhibit recrystallization and grain growth during annealing such as intermediate annealing. In order to fully obtain these effects, it is preferable that the total amount of the coarse precipitate forming elements is 0.0005% or more. However, if the total content of these elements exceeds 0.0100%, the total amount of sulfides or oxysulfides or both will be excessive, inhibiting recrystallization and grain growth during annealing such as intermediate annealing. Therefore, the total content of the elements that form coarse precipitates is set to 0.0100% or less.
　本実施形態において、上記以外の化学組成の残部はＦｅ及び不純物であってもよい。不純物とは、鋼原料および／又は製鋼過程で混入する元素を意味する。また、Ｆｅの一部に代えて、さらに、その他の元素を本発明効果を消失させない範囲で含有してもよい。例えば、Ｂ、Ｏ、Ｖ、Ｂｉ、Ｗ、Ｙを、それぞれ０．１０％以下含有してもよい。なお、不純物全体で合計５．００％以下であることが好ましく、１．００％以下であることがより好ましい。 In this embodiment, the remainder of the chemical composition other than those described above may be Fe and impurities. Impurities refer to elements that are mixed in the steel raw materials and/or the steelmaking process. In addition, other elements may be contained in place of a portion of Fe to the extent that the effect of the present invention is not lost. For example, B, O, V, Bi, W, and Y may each be contained in an amount of 0.10% or less. The total amount of impurities is preferably 5.00% or less, and more preferably 1.00% or less.
　化学組成については、以下の方法で求める。
　化学組成については、鋼の一般的な分析方法によって測定すればよい。例えば、化学組成はＩＣＰ－ＡＥＳ（Ｉｎｄｕｃｔｉｖｅｌｙ　Ｃｏｕｐｌｅｄ　Ｐｌａｓｍａ－Ａｔｏｍｉｃ　Ｅｍｉｓｓｉｏｎ　Ｓｐｅｃｔｒｏｍｅｔｒｙ）を用いて測定すればよい。具体的には、鋼板から採取した試験片を予め作成した検量線に基づいた条件で所定の測定装置にて測定することにより、化学組成が特定される。ＣおよびＳは燃焼－赤外線吸収法を用いて測定し、Ｎは不活性ガス融解－熱伝導度法を用いて測定すればよい。Ｏは不活性ガス融解－非分散型赤外線吸収法で測定すればよい。
　表面に絶縁被膜を有している場合には、ミニターなどにより機械的に除去したのちに分析に供すればよい。 The chemical composition is determined by the following method.
The chemical composition may be measured by a general analysis method for steel. For example, the chemical composition may be measured using ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry). Specifically, the chemical composition is specified by measuring a test piece taken from the steel plate with a predetermined measuring device under conditions based on a calibration curve created in advance. C and S may be measured using a combustion-infrared absorption method, and N may be measured using an inert gas fusion-thermal conductivity method. O may be measured using an inert gas fusion-non-dispersive infrared absorption method.
If the surface has an insulating coating, it may be mechanically removed using a minitor or the like before being subjected to analysis.
　次に、本実施形態に係る無方向性電磁鋼板の厚さについて説明する。本実施形態に係る
無方向性電磁鋼板の板厚は特に限定されない。本実施形態に係る無方向性電磁鋼板の好ましい板厚は、０．１０～０．５０ｍｍである。通常、板厚が薄くなれば、鉄損は低くなるものの、磁束密度が低くなる。この点を踏まえると、板厚が０．１０ｍｍ以上であれば、鉄損がより低く、かつ、磁束密度がより高くなる。また、板厚が０．５０ｍｍ以下であれば、低い鉄損を維持できる。 Next, the thickness of the non-oriented electrical steel sheet according to this embodiment will be described. 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 0.10 to 0.50 mm. Normally, as the sheet thickness becomes thinner, the iron loss becomes lower, but the magnetic flux density becomes lower. In view of this, if the sheet thickness is 0.10 mm or more, the iron loss becomes lower and the magnetic flux density becomes higher. Furthermore, if the sheet thickness is 0.50 mm or less, low iron loss can be maintained.
　次に、本実施形態に係る無方向性電磁鋼板の金属組織について説明する。以下、スキンパス圧延後の金属組織、最終焼鈍後の金属組織により各実施形態の無方向性電磁鋼板を特定する。 Next, the metal structure of the non-oriented electrical steel sheet according to this embodiment will be described. Below, the non-oriented electrical steel sheet of each embodiment will be specified based on the metal structure after skin pass rolling and the metal structure after final annealing.
　まず、特定する金属組織およびその特定方法について説明する。本実施形態で特定する金属組織は、鋼板の板面に平行な断面で特定されるもので、以下の手順によって特定する。 First, we will explain the metal structure to be identified and the method for identifying it. The metal structure to be identified in this embodiment is identified in a cross section parallel to the plate surface of the steel plate, and is identified by the following procedure.
　まず、板厚１／８厚位置が表出するように、試料を７／８の厚みまで研磨し、その研磨面（鋼板の板面側から１／８研磨した研磨面）を、ＳＥＭを用いて加速電圧２５ｋＶ、倍率１０００倍で、ＥＢＳＤ（Ｅｌｅｃｔｒｏｎ　Ｂａｃｋ　Ｓｃａｔｔｅｒｉｎｇ　Ｄｉｆｆｒａｃｔｉｏｎ）にて観察を行う。観察視野は、スキンパス圧延後の試料は５００μｍ×５００μｍ、歪取焼鈍後の試料は２０００μｍ×２０００μｍとする。観察は、いくつかの小区画に分けた数カ所で行っても良い。測定時のｓｔｅｐ間隔は、スキンパス圧延後の試料では０．３μｍ、歪取焼鈍後の試料では２．０μｍとする。ＥＢＳＤの観察データから一般的な方法により、以下の種類の面積、ＫＡＭ（Ｋｅｒｎｅｌ　Ａｖｅｒａｇｅ　Ｍｉｓｏｒｉｅｎｔａｔｉｏｎ）値を得る。
　各方位の面積はＥＢＳＤの観察視野からＩＰＦ（Ｉｎｖｅｒｓｅ　Ｐｏｌｅ　Ｆｉｇｕｒｅ）を計算することにより求めることができる。ＫＡＭ値はＯＩＭ　Ａｎａｌｙｓｉｓ等のソフトウェアを用いて測定点同士の方位差を計算することにより求めることが出来る。本開示ではＯＩＭ　Ａｎａｌｙｓｉｓ７．３を用いて、ＫＡＭ値へ参入する限度（ｔｏｌｅｒａｎｃｅ）を隣接ピクセルとの方位差５°以下とし、最隣接（１ｓｔ　ｎｅｉｇｈｂｏｒ）の測定点間の方位差を計算した値の平均値をＫＡＭ値として用いる。なお、「Ｓｅｔ　ｚｅｒｏ　ｐｏｉｎｔ　ｋｅｒｎｅｌ　ｔｏ　ｍａｘｉｍｕｍ　ｍｉｓｏｒｉｅｎｔａｔｉｏｎｓ」の設定はデフォルトのまま、チェックを入れる。 First, the sample is polished to a thickness of 7/8 so that the 1/8 thickness position is exposed, and the polished surface (polished surface polished to 1/8 from the plate surface side of the steel plate) is observed by EBSD (Electron Back Scattering Diffraction) using an SEM at an acceleration voltage of 25 kV and a magnification of 1000 times. The observation field is 500 μm × 500 μm for the sample after skin pass rolling and 2000 μm × 2000 μm for the sample after stress relief annealing. Observation may be performed at several locations divided into several small sections. The step interval during measurement is 0.3 μm for the sample after skin pass rolling and 2.0 μm for the sample after stress relief annealing. From the EBSD observation data, the following types of areas and KAM (Kernel Average Misorientation) values are obtained by a general method.
The area of each orientation can be obtained by calculating the IPF (Inverse Pole Figure) from the EBSD observation field of view. The KAM value can be obtained by calculating the orientation difference between measurement points using software such as OIM Analysis. In this disclosure, OIM Analysis 7.3 is used to set the limit (tolerance) for entering the KAM value to an orientation difference of 5° or less with adjacent pixels, and the average value of the calculated orientation difference between the nearest ( 1st neighbor) measurement points is used as the KAM value. Note that the setting of "Set zero point kernel to maximum misorientations" is left as the default and checked.
　Ｓtot：全面積（観察面積）
　Ｓtyl：以下の（２）式に従うテイラー因子Ｍが２．９超となる方位粒の合計面積
　Ｓtra：以下の（２）式に従うテイラー因子Ｍが２．９以下となる方位粒の合計面積
　Ｓ411：｛４１１｝方位粒の合計面積
　Ｓ100：｛１００｝方位粒の合計面積
　Ｋtyl：以下の（２）式に従うテイラー因子Ｍが２．９超となる方位粒の平均ＫＡＭ値
　Ｋ411：｛４１１｝方位粒の平均ＫＡＭ値
　ここで、結晶面方位の方位裕度に関しては１０°とする。また、以降、特定の結晶面方位を記述する際も、方位裕度は１０°とする。つまり、本開示で説明する特定の面方位から±１０°以内の面方位を有する結晶粒は、その特定の結晶方位を有する結晶粒として処理する。 S tot : Total area (observation area)
S tyl : Total area of oriented grains with Taylor factor M exceeding 2.9 according to the following formula (2) S tra : Total area of oriented grains with Taylor factor M of 2.9 or less according to the following formula (2) S 411 : Total area of {411} oriented grains S 100 : Total area of {100} oriented grains K tyl : Average KAM value of oriented grains with Taylor factor M exceeding 2.9 according to the following formula (2) K 411 : Average KAM value of {411} oriented grains Here, the orientation tolerance of the crystal plane orientation is 10°. In addition, hereinafter, when describing a specific crystal plane orientation, the orientation tolerance is also 10°. In other words, crystal grains having a plane orientation within ±10° of the specific plane orientation described in this disclosure are treated as crystal grains having that specific crystal orientation.
　ここで、テイラー因子Ｍは、以下の（２）式に従うものとする。
　Ｍ＝（cosφ×cosλ）-1　　　・・・（２）
φ：応力ベクトルと結晶のすべり方向ベクトルのなす角
λ：応力ベクトルと結晶のすべり面の法線ベクトルのなす角 Here, the Taylor factor M is assumed to comply with the following formula (2).
M=(cosφ×cosλ) -1 ...(2)
φ: Angle between the stress vector and the crystal slip direction vector λ: Angle between the stress vector and the normal vector of the crystal slip plane
　上記のテイラー因子Ｍは、結晶のすべり変形がすべり面｛１１０｝、または｛１１２｝、すべり方向＜１１１＞で起きると仮定し、板幅方向の変形は生じず板厚方向への圧縮変形と圧延方向への展伸変形が起こる場合のテイラー因子である。 The Taylor factor M above is the Taylor factor when it is assumed that crystal slip deformation occurs in the slip plane {110} or {112} and in the slip direction <111>, and no deformation occurs in the plate width direction, but compression deformation occurs in the plate thickness direction and elongation deformation occurs in the rolling direction.
　ここで、ＳＥＭ－ＥＢＳＤデータを用いてＯＩＭ　Ａｎａｌｙｓｉｓ７．３で解析することにより、テイラー因子を求める方法について説明する。ＯＩＭ　Ａｎａｌｙｓｉｓ７．３のＣｈａｒｔ作成を行う機能にて、対象（Ｔｙｐｅ）としてＴａｙｌｏｒ　Ｆａｃｔｏｒを選択する。テイラー因子を求めるための詳細条件は以下のとおりである。
　すべり系のＰｈａｓｅとしてＩｒｏｎ（Ａｌｐｈａ）を選択し、すべり系としては以下の２つを入力する。
　すべり面：１０１、すべり方向：１１－１、ＣＲＳＳ：０．２
　すべり面：１１２、すべり方向：１１－１、ＣＲＳＳ：０．２
　なお、すべり面とすべり方向は内積が０になる組み合わせを選べば、数字の順番、符号は違っていても同一の結果が得られる。ＣＲＳＳ（Ｃｒｉｔｉｃａｌ　Ｒｅｓｏｌｖｅｄ　Ｓｈｅａｒ　Ｓｔｒｅｓｓ：臨界分解剪断応力）は二つのすべり系で同一の値を入力する。
　Ｄｅｆｏｒｍａｔｉｏｎ　Ｇｒａｄｉｅｎｔとしては以下の圧延変形のテンソルを入力する。
　　　ＲＤ、ＴＤ、ＮＤ
ＲＤ　　１　　０　　０
ＴＤ　　０　　０　　０
ＮＤ　　０　　０　－１
　このような条件下での全測定点のテイラー因子をヒストグラムとして計算し、その結果からテイラー因子が２．９以上および２．９未満となる方位粒の面積率などに換算することが可能となる。 Here, a method for calculating the Taylor factor by analyzing SEM-EBSD data with OIM Analysis 7.3 will be described. In the function for creating charts in OIM Analysis 7.3, select Taylor Factor as the target (Type). The detailed conditions for calculating the Taylor factor are as follows:
Select Iron (Alpha) as the Phase of the slip system, and enter the following two items as the slip system.
Slide surface: 101, slide direction: 11-1, CRSS: 0.2
Slide surface: 112, slide direction: 11-1, CRSS: 0.2
In addition, if you select a combination of slip planes and slip directions that results in a dot product of 0, the same results will be obtained even if the order or signs of the numbers are different. Enter the same value for CRSS (Critical Resolved Shear Stress) for the two slip systems.
As the Deformation Gradient, the following rolling deformation tensor is input.
R.D., T.D., N.D.
RD 1 0 0
T.D. 0 0 0
N.D. 0 0 -1
The Taylor factors of all measurement points under such conditions are calculated as a histogram, and the results can be converted into the area ratio of oriented grains with Taylor factors of 2.9 or more and less than 2.9.
　次に、以下の実施形態１～２において、上記の面積、ＫＡＭ値により特徴を規定する。 Next, in the following embodiments 1 and 2, the features are defined by the above area and KAM value.
（実施形態１）
　まず、スキンパス圧延後の無方向性電磁鋼板の金属組織について説明する。この金属組織は、歪誘起粒成長を起こすのに十分な歪を蓄積しており、歪誘起粒成長が起こる前の初期段階の状態と位置付けることができる。スキンパス圧延後の鋼板の金属組織の特徴は、大まかには、目的とする方位の結晶粒が発達するための方位と、歪誘起粒成長を起こすため十分に蓄積された歪に関する条件とで規定される。 (Embodiment 1)
First, the metal structure of the non-oriented electrical steel sheet after skin-pass rolling will be explained. This metal structure has accumulated strain sufficient to cause strain-induced grain growth, and can be considered as an early stage before strain-induced grain growth occurs. The characteristics of the metal structure of the steel sheet after skin-pass rolling are roughly determined by the orientation for the development of crystal grains in the desired orientation and the conditions related to the strain sufficiently accumulated to cause strain-induced grain growth.
　実施形態１に係る無方向性電磁鋼板は各方位粒の面積が、以下の（３）式及び（４）式～（６）式を満たす。
　Ｓ411／Ｓ100＞１．００　　　・・・（３）
　０．２０≦Ｓtyl／Ｓtot≦０．８５　　　・・・（４）
　０．０５≦Ｓ411／Ｓtot≦０．８０　　　・・・（５）
　Ｓ411／Ｓtra≧０．５０　　　・・・（６） In the non-oriented electrical steel sheet according to the first embodiment, the area of each oriented grain satisfies the following formula (3) and formulas (4) to (6).
S 411 /S 100 >1.00...(3)
0.20≦S tyl /S tot ≦0.85 (4)
0.05≦S 411 /S tot ≦0.80 (5)
S 411 /S tra ≧0.50 (6)
　優先的に成長させるべき方位粒として｛４１１｝方位粒を中心として説明したが、｛４１１｝方位粒と同様にテイラー因子が比較的小さく加工による歪が蓄積しにくい方位であって、歪誘起粒成長において優先的に成長しうる方位粒は他にも多く存在する。その中で無方向性電磁鋼板に存在しやすい方位として、｛１００｝方位がある。この方位粒は、優先的に成長させるべき｛４１１｝方位粒とは競合する。一方でこの方位粒は、鋼板面内の方位をランダムに制御することが難しく、歪誘起粒成長で｛１００｝方位が発達してしまうと特性の鋼板面内異方性が大きくなってしまい不都合である。このため、実施形態１においては、テイラー因子が比較的小さく加工による歪が蓄積しにくい方位の中での｛４１１｝方位粒の存在比が確保されるよう規定する。面積比Ｓ411／Ｓ100は１．００超えである。つまり、｛４１１｝方位粒を｛１００｝方位粒よりも多く存させる。｛１００｝方位粒の発達を十分に抑制した上で｛４１１｝方位粒子を主方位とすると、全周平均（圧延方向、幅方向、圧延方向に対して４５度の方向、及び圧延方向に対して１３５度の方向、の平均）の磁気特性が改善される。
　好ましくは面積比Ｓ411／Ｓ100が２．０以上、より好ましくは面積比Ｓ411／Ｓ100が３．０以上である。  Although the description has been centered on the {411} orientation grains as the orientation grains that should be preferentially grown, there are many other orientation grains that have a relatively small Taylor factor like the {411} orientation grains and are unlikely to accumulate strain due to processing, and can grow preferentially in strain-induced grain growth. Among them, the {100} orientation is one orientation that is likely to exist in non-oriented electrical steel sheets. This orientation grain competes with the {411} orientation grains that should be preferentially grown. On the other hand, it is difficult to randomly control the orientation of this orientation grain in the steel sheet plane, and if the {100} orientation develops in strain-induced grain growth, the in-plane anisotropy of the properties of the steel sheet will increase, which is inconvenient. For this reason, in the first embodiment, the abundance ratio of {411} orientation grains is specified to be secured among orientations that have a relatively small Taylor factor and are unlikely to accumulate strain due to processing. The area ratio S 411 /S 100 is greater than 1.00. In other words, there are more {411} oriented grains than {100} oriented grains. By sufficiently suppressing the growth of {100} oriented grains and making the {411} oriented grains the main orientation, the magnetic properties are improved on an average around the circumference (average of the rolling direction, width direction, direction at 45 degrees to the rolling direction, and direction at 135 degrees to the rolling direction).
The area ratio S 411 /S 100 is preferably 2.0 or more, and more preferably 3.0 or more.
　面積比Ｓ411／Ｓ1０0の上限は、特に限定する必要はない。本開示の目的においては、
｛１００｝方位粒の存在がゼロで面積比Ｓ411／Ｓ100の値が無限大となっていても全く問題はない。しかしながら、実質｛１００｝方位粒をゼロにすることは製造上多大な負荷をもたらすことから面積比Ｓ411／Ｓ100が２０以下、より好ましくは面積比Ｓ411／Ｓ100が１０以下である。  The upper limit of the area ratio S411 / S100 does not need to be particularly limited.
There is no problem even if the number of {100} oriented grains is zero and the value of the area ratio S411 / S100 is infinite. However, since reducing the number of {100} oriented grains to zero substantially imposes a large burden on manufacturing, the area ratio S411 / S100 is preferably 20 or less , more preferably 10 or less.
　また、Ｓtylは、テイラー因子が比較的大きい方位の存在量である。歪誘起粒成長工程では、テイラー因子が小さく加工による歪が蓄積しにくい方位が、テイラー因子が大きく加工による歪が蓄積した方位を蚕食しながら優先的に成長する。このため、歪誘起粒成長により特殊な方位を発達させるには、Ｓtylはある程度の量が存在する必要がある。実施
形態１においては、全面積に対する面積比Ｓtyl／Ｓtotとして規定し、面積比Ｓtyl／Ｓtotを０．２０以上とする。面積比Ｓtyl／Ｓtotが０．２０未満では、歪誘起粒成長によって目的とする結晶方位が十分に発達しなくなる。好ましくは面積比Ｓtyl／Ｓtotが０．３０以上、より好ましくは０．５０以上である。 Moreover, S tyl is the amount of orientations with relatively large Taylor factors. In the strain-induced grain growth process, orientations with small Taylor factors and low strain accumulation due to processing grow preferentially while eroding orientations with large Taylor factors and high strain accumulation due to processing. For this reason, in order to develop a special orientation by strain-induced grain growth, a certain amount of S tyl must be present. In the first embodiment, the area ratio S tyl /S tot is defined as the area ratio S tyl /S tot to the total area, and the area ratio S tyl /S tot is set to 0.20 or more. If the area ratio S tyl /S tot is less than 0.20, the desired crystal orientation will not be sufficiently developed by strain-induced grain growth. The area ratio S tyl /S tot is preferably 0.30 or more, more preferably 0.50 or more.
　面積比Ｓtyl／Ｓtotの上限は、以下で説明する歪誘起粒成長工程で発達させるべき結晶方位粒の存在量と関連するが、その条件は単純に優先成長する方位と蚕食される方位の比率のみで決定されるものではない。まず、後述するように、歪誘起粒成長で発達させるべき｛４１１｝方位粒の面積比Ｓ411／Ｓtotが０．０５以上であることから、必然的に面積比Ｓtyl／Ｓtotは０．９５以下となる。しかし、面積比Ｓtyl／Ｓtotの存在量が過多となると、後述する歪との関連で、｛４１１｝方位粒の優先成長が起きなくなる。歪量との関連は後で詳述するが、実施形態１においては、面積比Ｓtyl／Ｓtotは０．８５以下となる。好ましくは面積比Ｓtyl／Ｓtotが０．７５以下、より好ましくは０．７０以下である。 The upper limit of the area ratio S tyl /S tot is related to the amount of crystal orientation grains to be developed in the strain-induced grain growth process described below, but the condition is not simply determined by the ratio of the orientation that grows preferentially and the orientation that is encroached upon. First, as described below, the area ratio S 411 /S tot of the {411} orientation grains to be developed in the strain-induced grain growth is 0.05 or more, so the area ratio S tyl /S tot is inevitably 0.95 or less. However, if the amount of the area ratio S tyl /S tot is excessive, preferential growth of the {411} orientation grains does not occur in relation to the strain described below. The relationship with the amount of strain will be described in detail later, but in embodiment 1, the area ratio S tyl /S tot is 0.85 or less. The area ratio S tyl /S tot is preferably 0.75 or less, more preferably 0.70 or less.
　以下で説明する歪誘起粒成長工程では、｛４１１｝方位粒を優先的に成長させる。｛４１１｝方位はテイラー因子が比較的小さく加工による歪が蓄積しにくい方位の１つであり、歪誘起粒成長工程において優先的に成長しうる方位である。実施形態１では、｛４１１｝方位粒の存在は必須であり、実施形態１では、｛４１１｝方位粒の面積比Ｓ411／Ｓtotを０．０５以上とする。｛４１１｝方位粒の面積比Ｓ411／Ｓtotが０．０５未満では、その後の歪誘起粒成長によって｛４１１｝方位粒が十分に発達しなくなる。好ましくは面積比Ｓ411／Ｓtotが０．１０以上、より好ましくは０．２０以上である。 In the strain-induced grain growth process described below, {411} orientation grains are preferentially grown. The {411} orientation is one of the orientations in which the Taylor factor is relatively small and strain caused by processing is unlikely to accumulate, and is an orientation that can preferentially grow in the strain-induced grain growth process. In the first embodiment, the presence of {411} orientation grains is essential, and in the first embodiment, the area ratio S 411 /S tot of the {411} orientation grains is set to 0.05 or more. If the area ratio S 411 /S tot of the {411} orientation grains is less than 0.05, the {411} orientation grains will not develop sufficiently due to the subsequent strain-induced grain growth. The area ratio S 411 /S tot is preferably 0.10 or more, more preferably 0.20 or more.
　面積比Ｓ411／Ｓtotの上限は、歪誘起粒成長で蚕食されるべき結晶方位粒の存在量に応じて決定される。実施形態１では歪誘起粒成長で蚕食されるべきテイラー因子が２．９超となる方位の面積比Ｓtyl／Ｓtotが０．２０以上であることから、面積比Ｓ411／Ｓtotは０．８０以下となる。ただし、歪誘起粒成長前の｛４１１｝方位粒の存在量が低い方が、粒成長の優位性が顕著となり、より｛４１１｝方位粒を発達させることが可能にもなる。これを考慮すれば、好ましくは面積比Ｓ411／Ｓtotは０．６０以下、より好ましくは０．５０以下、さらに好ましくは０．４０以下である。 The upper limit of the area ratio S 411 /S tot is determined according to the amount of crystal orientation grains to be eroded by strain-induced grain growth. In the first embodiment, the area ratio S tyl /S tot of the orientation in which the Taylor factor to be eroded by strain-induced grain growth exceeds 2.9 is 0.20 or more, so the area ratio S 411 /S tot is 0.80 or less. However, the lower the amount of {411} orientation grains before strain-induced grain growth, the more prominent the grain growth becomes, and the more the {411} orientation grains can be developed. In consideration of this, the area ratio S 411 /S tot is preferably 0.60 or less, more preferably 0.50 or less, and even more preferably 0.40 or less.
　優先的に成長させるべき方位粒として｛４１１｝方位粒を中心として説明したが、｛４１１｝方位粒と同様にテイラー因子が比較的小さく加工による歪が蓄積しにくい方位であって、歪誘起粒成長において優先的に成長しうる方位粒は他にも多く存在する。これらの方位粒は、優先的に成長させるべき｛４１１｝方位粒とは競合する。一方でこれらの方位粒は、鋼板面内の磁化容易軸方向（＜１００＞方向）が｛４１１｝方位粒ほどは多くなかったり、鋼板面内での方位選択性をランダムにすることが困難なため、歪誘起粒成長でこれら方位が発達してしまうと磁気特性が劣化したり、鋼板面内異方性が増大して不都合となる。このため、実施形態１においては、テイラー因子が十分に小さく加工による歪が蓄積しにくい方位の中での｛４１１｝方位粒の存在比が確保されるよう規定する。 Although the description has focused on the {411} orientation grains as the orientation grains that should be preferentially grown, there are many other orientation grains that have a relatively small Taylor factor like the {411} orientation grains and are less likely to accumulate distortion due to processing, and can grow preferentially in strain-induced grain growth. These orientation grains compete with the {411} orientation grains that should be preferentially grown. On the other hand, these orientation grains do not have as many easy axis of magnetization (<100> direction) in the steel sheet plane as the {411} orientation grains, and it is difficult to randomize the orientation selectivity in the steel sheet plane. Therefore, if these orientations develop in strain-induced grain growth, the magnetic properties will deteriorate and the in-plane anisotropy of the steel sheet will increase, which is inconvenient. For this reason, in embodiment 1, the presence ratio of {411} orientation grains is specified to be ensured among orientations that have a sufficiently small Taylor factor and are less likely to accumulate distortion due to processing.
　歪誘起粒成長において｛４１１｝方位粒と競合すると考えられる方位粒を含む、テイラー因子が２．９以下となる方位粒の面積をＳtraとする。そして、（６）式に示すように、面積比Ｓ411／Ｓtraを０．５０以上とし、｛４１１｝方位粒の成長の優位性を確保する。この面積比Ｓ411／Ｓtraが０．５０未満では、歪誘起粒成長によって｛４１１｝方位粒が十分に発達しなくなる。好ましくは面積比Ｓ411／Ｓtraが０．８０以上、より好ましくは０．９０以上である。一方、面積比Ｓ411／Ｓtraの上限は特に限定する必要がなく、テイラー因子が２．９以下となる方位粒がすべて｛４１１｝方位粒（Ｓ411／Ｓtra＝１．００）であっても構わない。 The area of the oriented grains with a Taylor factor of 2.9 or less, including the oriented grains that are considered to compete with the {411} oriented grains in strain-induced grain growth, is defined as S tra . As shown in formula (6), the area ratio S 411 /S tra is set to 0.50 or more to ensure the superiority of the growth of the {411} oriented grains. If the area ratio S 411 /S tra is less than 0.50, the {411} oriented grains do not develop sufficiently due to strain-induced grain growth. The area ratio S 411 /S tra is preferably 0.80 or more, more preferably 0.90 or more. On the other hand, there is no need to particularly limit the upper limit of the area ratio S 411 /S tra , and all the oriented grains with a Taylor factor of 2.9 or less may be {411} oriented grains (S 411 /S tra = 1.00).
　実施形態１は、上述の結晶方位に加えて、以下に説明する歪を組み合わせることで確実に｛４１１｝方位粒を成長させ、より優れた磁気特性を得ることができる。実施形態１において、歪に関する規定として、以下の（７）式を満たす必要がある。
　Ｋ411／Ｋtyl≦０．９９０　　　・・・（７） In the first embodiment, by combining the above-mentioned crystal orientation with the distortion described below, the {411} oriented grains can be reliably grown and better magnetic properties can be obtained. In the first embodiment, the following formula (7) must be satisfied as a rule regarding the distortion.
K 411 /K tyl ≦0.990 (7)
　歪に関する要件は（７）式によって規定される。（７）式は｛４１１｝方位粒に蓄積される歪（平均ＫＡＭ値）とテイラー因子が２．９超となる方位粒に蓄積される歪（平均ＫＡＭ値）との比である。ここで、ＫＡＭ値は同一粒内で隣接する測定点との方位差であり、歪の多い箇所ではＫＡＭ値は高くなる。結晶学的な観点において、例えば板厚方向と圧延方向に平行な面内での平面歪状態で板厚方向への圧縮変形を行う場合、つまり鋼板を単純に圧延する場合は、一般的にはこのＫ411とＫtylとの比Ｋ411／Ｋtylは１よりも小さくなる。しかし現実的には隣接する結晶粒による拘束、結晶粒内に存在する析出物、さらには変形時の工具（圧延ロールなど）との接触を含めたマクロ的な変形変動などの影響のため、ミクロ的に観察される結晶方位に応じた歪は多様な形態となる。このため、テイラー因子による純粋に幾何学的な方位の影響が現れにくくなる。また、例えば、同じ方位の粒であっても、粒径、粒の形態、隣接粒の方位や粒径、析出物の状態、板厚方向での位置などにより非常に大きな変動が形成される。さらに、一つの結晶粒でさえ、粒界近傍と粒内、変形帯などの形成により歪分布は大きく変動する。 The requirements for strain are stipulated by formula (7). Formula (7) is the ratio of the strain (average KAM value) accumulated in {411} oriented grains to the strain (average KAM value) accumulated in oriented grains with a Taylor factor of more than 2.9. Here, the KAM value is the orientation difference between adjacent measurement points within the same grain, and the KAM value is high at locations with a lot of strain. From a crystallographic point of view, for example, when compressive deformation is performed in the thickness direction in a plane strain state in a plane parallel to the thickness direction and the rolling direction, that is, when a steel sheet is simply rolled, the ratio K 411 /K tyl of K 411 to K tyl is generally smaller than 1. However, in reality, due to the influence of constraints by adjacent crystal grains, precipitates present in the crystal grains, and even macroscopic deformation fluctuations including contact with tools (rolling rolls, etc.) during deformation, the strain according to the crystal orientation observed microscopically takes various forms. For this reason, the influence of the purely geometric orientation due to the Taylor factor is less likely to appear. For example, even for grains with the same orientation, very large variations are formed depending on the grain size, grain morphology, the orientation and grain size of adjacent grains, the state of precipitates, the position in the plate thickness direction, etc. Furthermore, even for a single crystal grain, the strain distribution varies greatly due to the formation of deformation bands near and within the grain boundary.
　このような変動を考慮した上で、実施形態１において優れた磁気特性を得るためには、Ｋ411／Ｋtylを０．９９０以下とする。Ｋ411／Ｋtylが０．９９０超になると、蚕食されるべき領域の特殊性が失われるため、歪誘起粒成長が起きにくくなる。好ましくはＫ411／Ｋtylが０．９７０以下、より好ましくは０．９５０以下である。 Considering such fluctuations, in order to obtain excellent magnetic properties in embodiment 1, K411 / Ktyl is set to 0.990 or less. If K411 / Ktyl exceeds 0.990, the specificity of the region to be encroached is lost, making it difficult for strain-induced grain growth to occur. K411 / Ktyl is preferably 0.970 or less, more preferably 0.950 or less.
　実施形態１のスキンパス圧延後の状態での無方向性電磁鋼板の金属組織においては、結晶粒径については特に限定しない。これは、その後の最終焼鈍により適切な歪誘起粒成長が起きる状態において、結晶粒径との関係はそれほど強くないためである。つまり、目的とする適切な歪誘起粒成長が起きるかどうかは、鋼板の化学組成に加え、結晶方位毎の存在量（面積）の関係と、それぞれの方位毎の歪量の関係により、ほぼ決定できる。 In the metal structure of the non-oriented electrical steel sheet after skin pass rolling in embodiment 1, the grain size is not particularly limited. This is because the relationship with the grain size is not very strong in the state in which appropriate strain-induced grain growth occurs due to the subsequent final annealing. In other words, whether the desired appropriate strain-induced grain growth occurs can be determined largely by the chemical composition of the steel sheet, as well as the relationship between the abundance (area) of each crystal orientation and the relationship between the amount of strain for each orientation.
　ただし、結晶粒径があまりに粗大となると、歪により誘起されているものの実用的な温度域での十分な粒成長は生じにくくなる。また結晶粒径があまりに粗大になると磁気特性の劣化も回避し難くなる。このため実用的な平均結晶粒径は３００μｍ以下とすることが好ましい。より好ましくは１００μｍ以下、さらに好ましくは５０μｍ以下、特に好ましくは３０μｍ以下である。結晶粒径が細かいほど、結晶方位および歪の分布が適切に制御された際の歪誘起粒成長による目的とする結晶方位の発達は認識されやすい。ただしあまりに微細となると、上述のように歪を付与する加工において隣接粒との拘束のため、結晶方位毎の歪量の差異を形成しにくくなる。この観点からは平均結晶粒径は３μｍ以上であることが好ましく、より好ましくは８μｍ以上、さらに好ましくは１５μｍ以上である。 However, if the crystal grain size is too coarse, sufficient grain growth is difficult to occur in a practical temperature range, even though it is induced by strain. In addition, if the crystal grain size is too coarse, it becomes difficult to avoid deterioration of magnetic properties. For this reason, it is preferable that the practical average crystal grain size is 300 μm or less. More preferably, it is 100 μm or less, even more preferably, it is 50 μm or less, and particularly preferably, it is 30 μm or less. The finer the crystal grain size, the easier it is to recognize the development of the desired crystal orientation due to strain-induced grain growth when the crystal orientation and strain distribution are appropriately controlled. However, if it is too fine, it becomes difficult to form a difference in the amount of strain for each crystal orientation due to the constraints of adjacent grains in the processing to impart strain, as described above. From this point of view, it is preferable that the average crystal grain size is 3 μm or more, more preferably, 8 μm or more, and even more preferably, 15 μm or more.
（実施形態２）
　上述の実施形態１では、鋼板の歪をＫＡＭ値で特定することで鋼板としての特徴を規定した。これに対し、実施形態２では、実施形態１に記載の鋼板を十分に長時間焼鈍し、さらに粒成長させた鋼板について規定する。このような鋼板は、歪誘起粒成長がほぼ完了し、その結果、歪がほぼ完全に解放されるため、特性としては非常に好ましいものとなる。つまり、歪誘起粒成長で｛４１１｝方位粒を成長させ、さらに歪がほぼ完全に解放されるまで最終焼鈍で正常粒成長させた鋼板は、｛４１１｝方位への集積がより強い鋼板となる。実施形態２では、実施形態１に記載の鋼板を素材として、熱処理を行って得られる鋼板（すなわち、スキンパス圧延後の無方向性電磁鋼板に対し、最終焼鈍を行った無方向性電磁鋼板）の結晶方位、および結晶粒径について説明する。 (Embodiment 2)
In the above-mentioned embodiment 1, the characteristics of the steel sheet are specified by specifying the strain of the steel sheet by the KAM value. In contrast, in embodiment 2, the steel sheet described in embodiment 1 is annealed for a sufficiently long time and further grain-grown is specified. In such a steel sheet, strain-induced grain growth is almost completed, and as a result, the strain is almost completely released, so that the characteristics are very favorable. In other words, a steel sheet in which {411} orientation grains are grown by strain-induced grain growth and then normal grain growth is performed by final annealing until the strain is almost completely released becomes a steel sheet with stronger accumulation in the {411} orientation. In embodiment 2, the crystal orientation and crystal grain size of a steel sheet obtained by performing a heat treatment using the steel sheet described in embodiment 1 as a material (i.e., a non-oriented electrical steel sheet obtained by performing final annealing on a non-oriented electrical steel sheet after skin-pass rolling) will be described.
　最終焼鈍を行って得られる鋼板の結晶方位は、以下の（８）式～（１１）式を満たす。
　（８）式は、前述のスキンパス圧延後の無方向性電磁鋼板に関する（３）式と比較して数値範囲が異なっている。最終焼鈍中に生じる歪誘起粒成長により、｛４１１｝方位粒がさらに成長してその面積が増加することによって、全周平均（圧延方向、幅方向、圧延方向に対して４５度の方向、及び圧延方向に対して１３５度の方向、の平均）の磁気特性が改善される。
　（９）式～（１１）式の規定は、前述のスキンパス圧延後の無方向性電磁鋼板に関する（４）式～（６）式と比較して数値範囲が異なっている。最終焼鈍中に生じる歪誘起粒成
長により、｛４１１｝方位粒がさらに成長してその面積が増加するとともに、テイラー因子が２．９超となる方位粒が主として｛４１１｝方位粒に蚕食され、その面積がさらに減少しているからである。
　Ｓ411／Ｓ100＞２．００　　　・・・（８）
　Ｓtyl／Ｓtot＜０．５５　　　・・・（９）
　Ｓ411／Ｓtot＞０．３０　　　・・・（１０）
　Ｓ411／Ｓtra≧０．６０　　　・・・（１１） The crystal orientation of the steel sheet obtained by the final annealing satisfies the following formulas (8) to (11).
Formula (8) has a different numerical range compared to formula (3) related to the non-oriented electrical steel sheet after the above-mentioned skin-pass rolling. The strain-induced grain growth occurring during the final annealing causes the {411} orientation grains to grow further and increase their area, improving the magnetic properties on the circumferential average (average of the rolling direction, width direction, 45-degree direction relative to the rolling direction, and 135-degree direction relative to the rolling direction).
The definitions of formulas (9) to (11) have different numerical ranges compared to formulas (4) to (6) related to the non-oriented electrical steel sheet after skin-pass rolling described above. This is because, due to strain-induced grain growth that occurs during final annealing, {411} oriented grains grow further and their area increases, and orientation grains with a Taylor factor of more than 2.9 are mainly encroached upon by {411} oriented grains, further reducing their area.
S 411 /S 100 >2.00...(8)
S tyl /S tot <0.55...(9)
S 411 /S tot >0.30...(10)
S 411 /S tra ≧0.60 (11)
　実施形態２では面積比Ｓtyl／Ｓtotを０．５５未満とする。合計面積Ｓtylはゼロであっても構わない。面積比Ｓtyl／Ｓtotの上限は｛４１１｝方位粒の成長の進行の程度を示すパラメータの一つとして決定される。面積比Ｓtyl／Ｓtotが０．５５以上であることは、歪誘起粒成長の段階で蚕食されるべきテイラー因子が２．９超となる方位粒が十分に蚕食されていないことを示している。この場合、磁気特性が十分に向上しない。好ましくは面積比Ｓtyl／Ｓtotが０．４０以下、より好ましくは０．３０以下である。面積比Ｓtyl／Ｓtotは少ない方が好ましいので、下限は規定されず、０．００であってもよい。 In the second embodiment, the area ratio S tyl /S tot is less than 0.55. The total area S tyl may be zero. The upper limit of the area ratio S tyl /S tot is determined as one of the parameters indicating the degree of progress of the growth of the {411} oriented grains. The area ratio S tyl /S tot being 0.55 or more indicates that the oriented grains having a Taylor factor of more than 2.9 that should be eaten at the stage of strain-induced grain growth are not eaten sufficiently. In this case, the magnetic properties are not sufficiently improved. The area ratio S tyl /S tot is preferably 0.40 or less, more preferably 0.30 or less. Since the area ratio S tyl /S tot is preferably small, the lower limit is not specified and may be 0.00.
　また、実施形態２では面積比Ｓ411／Ｓtotを０．３０超とする。面積比Ｓ411／Ｓtotが０．３０以下では、磁気特性が十分に向上しない。好ましくは面積比Ｓ411／Ｓtotが０．４０以上、より好ましくは０．５０以上である。面積比Ｓ411／Ｓtotが１．００である状況とは、結晶組織のすべてが｛４１１｝方位粒であり、その他の方位粒が存在しない状況であるが、実施形態２はこの状況も対象とするものである。 In addition, in the second embodiment, the area ratio S411 / Stot is set to be more than 0.30. If the area ratio S411 / Stot is 0.30 or less, the magnetic properties are not sufficiently improved. The area ratio S411 / Stot is preferably 0.40 or more, more preferably 0.50 or more. The situation where the area ratio S411 / Stot is 1.00 means that all the crystal structure is oriented in the {411} direction and no other oriented grains exist, and the second embodiment is also intended for this situation.
　実施形態２でも、実施形態１と同様、歪誘起粒成長において｛４１１｝方位粒と競合していたと考えられる方位粒と｛４１１｝方位粒との関係も重要である。面積比Ｓ411／Ｓtraが十分に大きい場合には、歪誘起粒成長後の正常粒成長の状況においても｛４１１｝方位粒の成長の優位性が確保されており、磁気特性が良好となる。この面積比Ｓ411／Ｓtraが０．６０未満では、歪誘起粒成長によって｛４１１｝方位粒が十分に発達せず、歪誘起粒成長後の正常粒成長の状況において｛４１１｝方位粒以外のテイラー因子が小さな方位粒が相当程度に成長したことになり、磁気特性の面内異方性も大きくなる。したがって、実施形態２では面積比Ｓ411／Ｓtraを０．６０以上とする。好ましくは面積比Ｓ411／Ｓtraが０．７０以上、より好ましくは０．８０以上である。一方、面積比Ｓ411／Ｓtraの上限は特に限定する必要がなく、テイラー因子が２．９以下である方位粒がすべて｛４１１｝方位粒であっても構わない。 In the second embodiment, as in the first embodiment, the relationship between the {411} oriented grains and the {411} oriented grains, which are considered to have competed with the {411} oriented grains in the strain-induced grain growth, is also important. When the area ratio S 411 /S tra is sufficiently large, the superiority of the {411} oriented grains is ensured even in the situation of normal grain growth after the strain-induced grain growth, and the magnetic properties are good. When the area ratio S 411 /S tra is less than 0.60, the {411} oriented grains do not develop sufficiently due to the strain-induced grain growth, and the orientation grains with small Taylor factors other than the {411} oriented grains grow to a considerable extent in the situation of normal grain growth after the strain-induced grain growth, and the in-plane anisotropy of the magnetic properties also becomes large. Therefore, in the second embodiment, the area ratio S 411 /S tra is set to 0.60 or more. The area ratio S 411 /S tra is preferably 0.70 or more, more preferably 0.80 or more. On the other hand, there is no need to set a particular upper limit for the area ratio S 411 /S tra , and all grains having a Taylor factor of 2.9 or less may be grains having the {411} orientation.
　また、平均結晶粒径の範囲については特に限定はしないが、平均結晶粒径があまりに粗大になると磁気特性の劣化も回避し難くなる。このため、実施形態１と同様、実施形態２において相対的に粗大な粒である｛４１１｝方位粒の実用的な平均結晶粒径は、５００μｍ以下とすることが好ましい。より好ましくは｛４１１｝方位粒の平均結晶粒径が４００μｍ以下、さらに好ましくは３００μｍ以下、特に好ましくは２００μｍ以下である。一方、｛４１１｝方位粒の平均結晶粒径の下限は、｛４１１｝方位の十分な優先成長を確保している状態を想定すれば、｛４１１｝方位粒の平均結晶粒径が４０μｍ以上であることが好ましく、より好ましくは６０μｍ以上、さらに好ましくは８０μｍ以上である。 Although there is no particular limit to the range of the average crystal grain size, if the average crystal grain size becomes too coarse, it becomes difficult to avoid deterioration of the magnetic properties. For this reason, as in the first embodiment, the practical average crystal grain size of the {411} orientation grains, which are relatively coarse grains in the second embodiment, is preferably 500 μm or less. More preferably, the average crystal grain size of the {411} orientation grains is 400 μm or less, even more preferably 300 μm or less, and particularly preferably 200 μm or less. On the other hand, the lower limit of the average crystal grain size of the {411} orientation grains is preferably 40 μm or more, more preferably 60 μm or more, and even more preferably 80 μm or more, assuming that sufficient preferential growth of the {411} orientation is ensured.
［特性］
　最終焼鈍後の無方向性電磁鋼板は、上記の通り化学組成、金属組織を制御しているので、圧延方向、幅方向の平均だけでなく、全周平均（圧延方向、幅方向、圧延方向に対して４５度の方向、圧延方向に対して１３５度の方向、の平均）で優れた磁気特性（低い鉄損）を得ることができる。
　ここで言う圧延方向、幅方向は、得られる無方向性電磁鋼板の圧延方向、幅方向である。 [Characteristic]
Since the chemical composition and metal structure of the non-oriented electrical steel sheet after final annealing are controlled as described above, it is possible to obtain excellent magnetic properties (low iron loss) not only on average in the rolling direction and width direction, but also on average around the circumference (on average in the rolling direction, width direction, directions at 45 degrees to the rolling direction, and directions at 135 degrees to the rolling direction).
The rolling direction and width direction referred to here are the rolling direction and width direction of the obtained non-oriented electrical steel sheet.
　実施形態２の無方向性電磁鋼板は、圧延方向となす角度が０°、４５°、９０°となる３つの方向において、４５°方向の磁気特性が最も優れる。実施形態２において４５°方向の磁気特性は、圧延方向と＋４５°と－４５°をなす２つの方向についての磁気特性の平均値である。 The non-oriented electrical steel sheet of embodiment 2 has the best magnetic properties in the 45° direction among the three directions that form angles of 0°, 45°, and 90° with the rolling direction. In embodiment 2, the magnetic properties in the 45° direction are the average value of the magnetic properties in the two directions that form angles of +45° and -45° with the rolling direction.
　実施形態２の無方向性電磁鋼板の磁束密度を測定したとき、圧延方向に対して４５°方向の磁束密度Ｂ５０は１．７５Ｔ以上が好ましい。なお、実施形態２に係る無方向性電磁鋼板では、圧延方向に対して４５°方向の磁束密度が高く、板面内異方性が小さくかつ全周平均（全方向平均）でも高い磁束密度が得られる。 When the magnetic flux density of the non-oriented electrical steel sheet of embodiment 2 is measured, the magnetic flux density B50 in the direction at 45° to the rolling direction is preferably not less than 1.75 T. Note that in the non-oriented electrical steel sheet according to embodiment 2, the magnetic flux density in the direction at 45° to the rolling direction is high, the in-plane anisotropy is small, and a high magnetic flux density can be obtained even in the circumferential average (all-direction average).
　実施形態２の無方向性電磁鋼板では、圧延方向における磁束密度Ｂ５０の値をＢ５０Ｌ、圧延方向に対して４５°方向の磁束密度Ｂ５０の値をＢ５０Ｄ、圧延方向に対して９０°方向の磁束密度Ｂ５０の値をＢ５０Ｃとすると、Ｂ５０Ｄが相対的に高く、Ｂ５０Ｌ及びＢ５０Ｃが相対的に低いという磁束密度の異方性がみられる。 In the non-oriented electrical steel sheet of embodiment 2, if the magnetic flux density B50 value in the rolling direction is B50L , the magnetic flux density B50 value in the 45° direction to the rolling direction is B50D , and the magnetic flux density B50 value in the 90° direction to the rolling direction is B50C , then anisotropy of the magnetic flux density is observed, in which B50D is relatively high and B50L and B50C are relatively low.
　実施形態２の無方向性電磁鋼板では、Ｂ５０Ｄと、Ｂ５０ＬとＢ５０Ｃの平均値とを用いて、以下の（Ａ）式を満たすことがより好ましい。 In the non-oriented electrical steel sheet of embodiment 2, it is more preferable that the following formula (A) is satisfied by using B 50D and the average value of B 50L and B 50C .
　｜Ｂ５０Ｄ－（Ｂ５０Ｌ+Ｂ５０Ｃ）／２｜≦０．２　・・・（Ａ） |B 50D -(B 50L +B 50C )/2|≦0.2...(A)
　上記（Ａ）式の左辺の値の下限は、特に制限はなく、ゼロであることが好ましい。 There is no particular lower limit for the value on the left side of the above formula (A), but it is preferable that it be zero.
　磁束密度の測定は、圧延方向に対して４５°、０°方向等から５５ｍｍ角の試料を切り出し，単板磁気測定装置を用いて行うことができる。 The magnetic flux density can be measured by cutting a 55 mm square sample at 45°, 0°, etc., relative to the rolling direction and using a single sheet magnetic measuring device.
　磁気測定はＪＩＳ　Ｃ　２５５０－１（２０１１）及びＪＩＳ　Ｃ　２５５０－３（２０１９）に記載の測定方法で行ってもよいし、ＪＩＳ　Ｃ　２５５６（２０１５）に記載の測定方法で行っても良い。また、試料が微小であり、上記ＪＩＳに記載の測定が出来ない場合、電磁回路はＪＩＳ　Ｃ　２５５６（２０１５）に準じた５５ｍｍ角の試験片や更に微小な試験片を測定できる装置を用いて測定しても良い。 Magnetic measurements may be performed using the methods described in JIS C 2550-1 (2011) and JIS C 2550-3 (2019), or the methods described in JIS C 2556 (2015). In addition, if the sample is too small to be measured using the methods described in the above JIS, the electromagnetic circuit may be measured using a 55 mm square test piece conforming to JIS C 2556 (2015), or a device capable of measuring even smaller test pieces.
　次に、本実施形態に係る無方向性電磁鋼板の製造方法の一例について説明する。本実施形態に係る無方向性電磁鋼板は、熱間圧延工程、冷間圧延工程、中間焼鈍工程、スキンパス圧延工程、最終焼鈍工程）を含む製造方法によって得られる。
　以下、各工程の好ましい条件について説明する。
　以下、本実施形態において、Ａｒ３温度は、上記（１）式で定めた変態温度Ａｒ３（℃）である。 Next, an example of a method for producing the non-oriented electrical steel sheet according to the present embodiment will be described. The non-oriented electrical steel sheet according to the present embodiment is obtained by a production method including a hot rolling step, a cold rolling step, an intermediate annealing step, a skin pass rolling step, and a final annealing step.
Preferred conditions for each step will now be described.
Hereinafter, in this embodiment, the Ar3 temperature is the transformation temperature Ar3 (°C) defined by the above formula (1).
（熱間圧延工程）
　熱間圧延工程では、上述の化学組成を満たす鋼材に対して熱間圧延を実施して熱間圧延鋼板を製造する。熱間圧延工程は、加熱過程と、圧延過程とを備える。 (Hot rolling process)
In the hot rolling process, hot rolling is performed on the steel material satisfying the above-mentioned chemical composition to produce a hot rolled steel sheet. The hot rolling process includes a heating process and a rolling process.
　鋼材は、例えば通常の連続鋳造によって製造されるスラブであり、上述した組成の鋼材は周知の方法で製造される。たとえば、転炉又は電気炉等で溶鋼を製造する。製造された溶鋼に対して脱ガス設備等で二次精錬して、上記化学組成を有する溶鋼とする（その後の工程では化学組成は実質的に変化しない）。溶鋼を用いて連続鋳造法又は造塊法によりスラブを鋳造する。鋳造されたスラブを分塊圧延してもよい。 The steel material is, for example, a slab produced by normal continuous casting, and steel material of the above-mentioned composition is produced by a well-known method. For example, molten steel is produced in a converter or electric furnace. The produced molten steel is subjected to secondary refining in a degassing facility or the like to produce molten steel having the above-mentioned chemical composition (the chemical composition does not change substantially in subsequent processes). The molten steel is cast into a slab by a continuous casting method or an ingot casting method. The cast slab may be rolled into blooms.
　加熱過程では、上述の化学組成を有する鋼材を１０００～１２００℃に加熱することが好ましい。具体的には、鋼材を加熱炉又は均熱炉に装入して、炉内にて加熱する。加熱炉又は均熱炉での上記加熱温度での保持時間は特に限定されないが、例えば３０～２００時間である。 In the heating process, it is preferable to heat the steel material having the above-mentioned chemical composition to 1000 to 1200°C. Specifically, the steel material is placed in a heating furnace or a soaking furnace and heated in the furnace. The holding time at the above-mentioned heating temperature in the heating furnace or soaking furnace is not particularly limited, but is, for example, 30 to 200 hours.
　圧延過程では、加熱過程により加熱された鋼材に対して、複数回パスの圧延を実施して、熱間圧延鋼板を製造する。ここで、「パス」とは、一対のワークロールを有する１つの圧延スタンドを鋼板が通過して圧下を受けることを意味する。熱間圧延はたとえば、一列に並んだ複数の圧延スタンド（各圧延スタンドは一対のワークロールを有する）を含むタンデム圧延機を用いてタンデム圧延を実施して、複数回パスの圧延を実施してもよいし、一対のワークロールを有するリバース圧延を実施して、複数回パスの圧延を実施してもよい。生産性の観点から、タンデム圧延機を用いて複数回の圧延パスを実施するのが好ましい。 In the rolling process, multiple passes of rolling are performed on the steel material heated in the heating process to produce hot-rolled steel plate. Here, "pass" means that the steel plate passes through one rolling stand having a pair of work rolls and is reduced. Hot rolling may be performed, for example, by tandem rolling using a tandem rolling mill including multiple rolling stands arranged in a row (each rolling stand having a pair of work rolls) to perform multiple passes, or by reverse rolling using a pair of work rolls to perform multiple passes. From the viewpoint of productivity, it is preferable to perform multiple rolling passes using a tandem rolling mill.
　圧延過程（粗圧延および仕上げ圧延）での圧延は、上述した鋼材を加熱し、熱間圧延を施す。鋼材は、例えば通常の連続鋳造によって製造されるスラブである。スラブの加熱はＡｒ３温度以上とし鋼組織がγ相となる温度域とする。熱間圧延は鋼組織がγ相となる温度域（以降、この温度域をγ域と記述することがある）で開始され、仕上げ圧延の最終パスを含む必要な数パスを除いてγ域で実施し、最終パスを含む必要な数パスを鋼組織にα相が存在する温度域（以降、この温度域をα域と記述することがある）で実施して完了させる。一般的には、粗圧延及び仕上げ圧延の前段～中段をγ域で行い、仕上圧延の後段をα域で行うこととなる。本実施形態では、最終的なα域での圧延の直前のＡｒ３温度以上Ａｒ３＋２０℃以下の温度域での圧下率を１０％以上とする。さらに、仕上げ圧延温度ＦＴ以上Ａｒ３温度未満の温度域での圧下率は複数パスで圧延する場合も考慮して合計で１５％以上とする。
　なお、仕上げ圧延温度ＦＴとは、仕上げ圧延直後の熱間圧延鋼板の表面温度を指す。
仕上げ圧延温度ＦＴの下限は特に制限はないが、例えば、Ａｒ３温度－１００℃以上とする。 In the rolling process (rough rolling and finish rolling), the above-mentioned steel material is heated and hot rolled. The steel material is, for example, a slab manufactured by normal continuous casting. The slab is heated to the Ar 3 temperature or higher, which is a temperature range in which the steel structure becomes a γ phase. Hot rolling is started in a temperature range in which the steel structure becomes a γ phase (hereinafter, this temperature range may be described as the γ range), and is performed in the γ range except for a necessary number of passes including the final pass of the finish rolling, and is completed by performing a necessary number of passes including the final pass in a temperature range in which the α phase exists in the steel structure (hereinafter, this temperature range may be described as the α range). In general, the front to middle stages of rough rolling and finish rolling are performed in the γ range, and the rear stage of finish rolling is performed in the α range. In this embodiment, the reduction ratio in the temperature range from the Ar 3 temperature or higher to Ar 3 +20°C or lower immediately before the final rolling in the α range is 10% or more. Furthermore, the rolling reduction in the temperature range of the finish rolling temperature FT or higher and lower than the Ar 3 temperature is set to 15% or more in total, taking into consideration the case where rolling is performed in multiple passes.
The finish rolling temperature FT refers to the surface temperature of the hot-rolled steel sheet immediately after finish rolling.
The lower limit of the finish rolling temperature FT is not particularly limited, but is set to, for example, Ar3 temperature -100°C or more.
　最終的なα域での圧延の直前でのＡｒ３＋２０℃超の温度域での圧延は相変態前の加工γ粒の粒径への影響がほどんとなく、変態後に粗大な加工α粒が形成され、最終製品での｛４１１｝結晶方位への集積とは無関係となる。
　最終的なα域での圧延の直前のＡｒ３温度以上Ａｒ３＋２０℃以下の温度域での圧延率が１０％未満となると相変態前の加工γ粒への歪の蓄積が不足し、粗大な加工α粒が形成され、最終製品での｛４１１｝結晶方位への集積が起こりづらくなる。Ａｒ３温度以上Ａｒ３＋２０℃以下の温度域での圧延率は、好ましくは１５％以上、より好ましくは２０％以上とする。圧下率の合計の上限は規定しないが、４０％超えとすることは圧延機の負荷が高くなりすぎることから、４０％を上限とすることが好ましい。
　最終的なα域での仕上げ圧延温度ＦＴ以上Ａｒ３温度未満の温度域での圧下率の合計が１５％未満となると加工γ粒から相変態した後の加工α粒にα域での加工歪を十分に蓄積することができず、最終製品での｛４１１｝結晶方位への集積が起こりづらくなる。仕上げ圧延温度ＦＴ以上Ａｒ３温度未満の温度域での圧下率は、好ましくは２０％以上、より好ましくは２５％以上とする。圧下率の合計の上限は規定しないが、４０％超えとすることは圧延機の負荷が高くなりすぎることから、４０％を上限とすることが好ましい。
　本実施形態では、熱間圧延における圧下率ＲＲ０は、次のとおり定義される。
　圧下率ＲＲ０（％）＝（１－熱間圧延での該当温度域での圧延後の板厚／熱間圧延での該当温度域での圧延前の板厚）×１００ Rolling in a temperature range above Ar3 + 20°C just before the final rolling in the α region has almost no effect on the grain size of the deformed γ grains before the phase transformation, and coarse deformed α grains are formed after the transformation, which is unrelated to the accumulation in the {411} crystal orientation in the final product.
If the rolling reduction ratio in the temperature range from Ar3 temperature to Ar3 + 20°C just before the final rolling in the α region is less than 10%, the accumulation of strain in the processed γ grains before the phase transformation is insufficient, coarse processed α grains are formed, and accumulation in the {411} crystal orientation in the final product becomes difficult. The rolling reduction ratio in the temperature range from Ar3 temperature to Ar3 + 20°C is preferably 15% or more, more preferably 20% or more. There is no upper limit for the total rolling reduction ratio, but since a reduction ratio exceeding 40% places too much strain on the rolling mill, it is preferable to set the upper limit at 40%.
If the total reduction in the temperature range from the finish rolling temperature FT to the Ar3 temperature in the final α region is less than 15%, the processed α grains after phase transformation from the processed γ grains cannot sufficiently accumulate processing strain in the α region, and accumulation in the {411} crystal orientation in the final product is difficult. The reduction in the temperature range from the finish rolling temperature FT to the Ar3 temperature is preferably 20% or more, more preferably 25% or more. There is no upper limit to the total reduction, but since a reduction exceeding 40% increases the load on the rolling mill too much, it is preferable to set the upper limit at 40%.
In this embodiment, the reduction ratio RR0 in the hot rolling is defined as follows.
Reduction rate RR0 (%) = (1 - thickness after rolling in the corresponding temperature range in hot rolling / thickness before rolling in the corresponding temperature range in hot rolling) x 100
　上記のα域での圧延の下限温度については特に限定するものではないが、圧延温度が低下すると圧延機の負荷が高くなることから、６００℃以上とすることが好ましい。
　なお、上記の圧延温度は、ロール接触および冷却潤滑剤による温度低下と加工による温度上昇が競合し、圧延パスの加工途中で規定の判定温度（Ａｒ３温度、またはＡｒ３＋２０℃）の上下で変動することが考えられる。本実施形態ではこのような状況を次のように処理する。
　圧延パスにおいて、入側の温度をＴＰＩ（℃）、入側の板厚をＴＣＩ（ｍｍ）、出側の温度をＴＰＯ（℃）、出側の板厚をＴＣＯ（ｍｍ）とし、さらに圧延パス中の板厚変化と温度変化は単純に直線的な関係を有したまま変化すると仮定する。つまり、圧延パス中の特定時点での板厚をＴＣａ（ｍｍ）、温度をＴＰａ（℃）とすると、圧延パス中は以下の式が常に成り立つものと仮定する。
（ＴＣａ－ＴＣＯ）／（ＴＣＩ－ＴＣＯ）＝（ＴＰａ－ＴＰＯ）／（ＴＰＩ－ＴＰＯ）
　これにより、本製造法における規定の判定温度（Ａｒ３温度、またはＡｒ３＋２０℃）に圧延パス中に到達した場合でも、その時点での板厚を決定することが可能となる。
　すなわち圧延パス途中に特定の温度ＴＰａ（℃）に到達した時点での板厚ＴＣａ（ｍｍ）は、
　ＴＣａ＝ＴＣＯ＋（ＴＣＩ－ＴＣＯ）×（ＴＰａ－ＴＰＯ）／（ＴＰＩ－ＴＰＯ）
　により得ることができる。 The lower limit temperature for rolling in the α region is not particularly limited, but since a lower rolling temperature increases the load on the rolling mill, it is preferable to set the lower limit temperature to 600° C. or higher.
The rolling temperature may fluctuate above or below the specified judgment temperature ( Ar3 temperature, or Ar3 + 20°C) during the rolling pass due to the competition between the temperature drop caused by roll contact and cooling lubricant and the temperature rise caused by processing. In this embodiment, such a situation is handled as follows.
In a rolling pass, it is assumed that the temperature on the entry side is TPI (°C), the thickness on the entry side is TCI (mm), the temperature on the exit side is TPO (°C), and the thickness on the exit side is TCO (mm), and further that the thickness change and the temperature change during the rolling pass change while having a simple linear relationship. In other words, if the thickness at a specific point in time during a rolling pass is TCa (mm) and the temperature is TPa (°C), it is assumed that the following formula always holds during the rolling pass.
(TCa-TCO)/(TCI-TCO)=(TPa-TPO)/(TPI-TPO)
This makes it possible to determine the plate thickness at that time point even when the prescribed judgment temperature in this production method (Ar 3 temperature, or Ar 3 +20° C.) is reached during a rolling pass.
That is, the plate thickness TCa (mm) at the time when a specific temperature TPa (°C) is reached during the rolling pass is
TCa=TCO+(TCI-TCO)×(TPa-TPO)/(TPI-TPO)
can be obtained by:
　ここで、注意すべきは、上記仮定は圧延パスの出側温度が入側温度よりも高くなることも想定したものとしていることである。すなわち当該パスの入側温度ＴＰＩがＡｒ３温度未満であった鋼板が当該パス内での加工発熱により温度上昇してＡｒ３温度以上の出側温度ＴＰＯで排出される状況においても、当該パス内の後半で本開示に必要なγ域（Ａｒ３温度以上Ａｒ３＋２０℃以下の温度域）での圧延が施されたと判断する。
　また、Ａｒ３温度を挟んだ温度の変動が複数パスに亘って生じることも考えられる。このような場合、本実施形態においては、α域の圧延条件については、「α域での最終の圧延加工」を対象とする。また、γ域の圧延条件については、「上記『α域での最終の圧延加工』」の直前のγ域での圧延加工」を対象とする。つまり、γ域で熱間圧延を開始した後の圧延温度が、γ域（熱延開始）⇒α域１⇒γ域１⇒α域２⇒γ域２⇒α域３（熱延終了）のように変動した場合、α域３とγ域２が本実施形態の条件に合致すれば、本開示鋼板を得ることが可能である。 It should be noted that the above assumption also assumes that the exit temperature of the rolling pass is higher than the entry temperature. In other words, even in a situation where a steel sheet whose entry temperature TPI of the pass is lower than the Ar3 temperature rises in temperature due to processing heat in the pass and is discharged at an exit temperature TPO of Ar3 temperature or higher, it is determined that the steel sheet has been rolled in the γ range (temperature range of Ar3 temperature or higher and Ar3 + 20°C or lower) required for the present disclosure in the latter half of the pass.
It is also conceivable that the temperature fluctuations on either side of the Ar 3 temperature may occur over multiple passes. In such a case, in this embodiment, the rolling conditions in the α region are the "final rolling process in the α region". In addition, the rolling conditions in the γ region are the "rolling process in the γ region immediately before the above-mentioned "final rolling process in the α region". In other words, when the rolling temperature after starting hot rolling in the γ region changes as follows: γ region (start of hot rolling) ⇒ α region 1 ⇒ γ region 1 ⇒ α region 2 ⇒ γ region 2 ⇒ α region 3 (end of hot rolling), if the α region 3 and the γ region 2 meet the conditions of this embodiment, it is possible to obtain the disclosed steel sheet.
　各パスでの圧延温度は、例えば対象パスの圧下を行う圧延スタンドの入側または出側に設置された測温計により、測温可能である。また、温度域が本開示範囲内となる圧延スタンドの入側および出側のすべてに測温計を設置する必要はなく、その前後に適宜設置された測温計の実績温度から計算により途中の圧延スタンドでの圧延温度を計算しても良い。むしろ、現状の熱間圧延では、このような計算による温度を用いた制御が行われることが通常である。
　なお、仕上げ圧延温度ＦＴは、Ａｒ３温度未満とすることが好ましい。 The rolling temperature in each pass can be measured, for example, by a thermometer installed at the entry or exit of the rolling stand that performs the reduction of the target pass. It is not necessary to install thermometers at the entry and exit of all rolling stands whose temperature range falls within the range disclosed herein, and the rolling temperature at intermediate rolling stands may be calculated from the actual temperatures of thermometers appropriately installed before and after them. Rather, in current hot rolling, control using such calculated temperatures is usually performed.
The finish rolling temperature FT is preferably set to be lower than the Ar3 temperature.
　その後、熱間圧延板焼鈍は行わずに、熱間圧延鋼板を巻き取る。巻き取り時の温度は、４５０℃超６５０℃以下であることが好ましい。熱間圧延後の熱間圧延鋼板を４５０℃超６５０℃以下で巻き取ることで、α域熱延によって導入されたひずみが適度に緩和されることで冷延前の結晶組織を微細化することができ、中間焼鈍時の再結晶挙動に影響を及ぼし、中間焼鈍板段階で｛１００｝結晶方位よりも｛４１１｝結晶方位の発達が促進される。バルジングの際に磁気特性の優れた｛４１１｝結晶方位を富化出来るという効果が得られる。巻き取り時の温度は、５００℃～６００℃がより好ましく、５２０℃～５８０℃であることがさらに好ましい。 Then, the hot-rolled steel sheet is coiled without annealing the hot-rolled sheet. The temperature during coiling is preferably more than 450°C and less than 650°C. By coiling the hot-rolled steel sheet after hot rolling at more than 450°C and less than 650°C, the strain introduced by the α-region hot rolling is moderately relaxed, making it possible to refine the crystal structure before cold rolling, which affects the recrystallization behavior during intermediate annealing and promotes the development of the {411} crystal orientation rather than the {100} crystal orientation at the intermediate annealed sheet stage. This has the effect of enriching the {411} crystal orientation, which has excellent magnetic properties, during bulging. The temperature during coiling is more preferably 500°C to 600°C, and even more preferably 520°C to 580°C.
（冷間圧延工程）
　冷間圧延工程では、冷却工程後の熱間圧延鋼板に対して冷間圧延を行って冷間圧延鋼板を得る。具体的には、熱間圧延後、酸洗を経て、熱間圧延鋼板に対して冷間圧延を行う。冷間圧延では圧下率を８０％～９２％とすることが好ましい。なお、圧下率が高いほどその後のバルジングによって｛４１１｝結晶方位を有する結晶粒が成長しやすくなるが、板形状が劣化し、操業が困難になりやすくなる。 (Cold rolling process)
In the cold rolling process, the hot rolled steel sheet after the cooling process is cold rolled to obtain a cold rolled steel sheet. Specifically, after hot rolling, the hot rolled steel sheet is pickled and then cold rolled. In the cold rolling, the reduction is preferably 80% to 92%. Note that the higher the reduction, the easier it is for crystal grains having the {411} crystal orientation to grow due to subsequent bulging, but the sheet shape deteriorates and operation becomes more difficult.
　また、冷間圧延を行う際に、圧延形状比が５．０以下となるような圧延を１パス以上行うことが好ましい。圧延形状比を５．０以下とすることでせん断ひずみが付加され、冷間圧延中の｛４１１｝結晶方位の形成が促される。この観点からは４．５以下とすることが好ましく、４．０以下にすることが更に好ましい。圧延形状比の下限は特に定めるものではないが、１．０未満に制御することは困難なことから、これを下限とすることが好ましい。
　なお、圧延形状比は、以下の（ａ）式により定義される。
　Γ＝ｌｄ／ｈｍ　・・・（ａ）
　但し、上記（ａ）式中の各記号は、以下により定義される。
　Γ：圧延形状比
　ｌｄ：投影接触弧長
　ｈｍ：平均板厚 In addition, when cold rolling is performed, it is preferable to perform one or more passes of rolling so that the rolling shape ratio is 5.0 or less. By setting the rolling shape ratio to 5.0 or less, shear strain is added, and the formation of the {411} crystal orientation during cold rolling is promoted. From this viewpoint, it is preferable to set it to 4.5 or less, and more preferably to set it to 4.0 or less. Although there is no particular lower limit for the rolling shape ratio, it is preferable to set it to this lower limit since it is difficult to control it to less than 1.0.
The shape ratio is defined by the following formula (a).
Γ=ld/hm...(a)
In the above formula (a), each symbol is defined as follows.
Γ: Rolling shape ratio ld: Projected contact arc length hm: Average plate thickness
　また、上記ｌｄおよびｈｍは、以下の（ｂ）および（ｃ）式から算出される。
　ｌｄ＝√（Ｒ×（Ｈ－ｈ））　・・・（ｂ）
　ｈｍ＝（Ｈ＋２ｈ）／３　・・・（c）
　但し、上記（ｂ）式及び（ｃ）式中の各記号は、以下により定義される。
　Ｒ：ロール半径
　Ｈ：入側板厚（当該パスの圧延機に入る前の板厚）
　ｈ：出側板厚（当該パスの圧延機から出たときの板厚） Moreover, the above ld and hm are calculated from the following equations (b) and (c).
ld=√(R×(H-h))...(b)
hm=(H+2h)/3...(c)
In the above formulas (b) and (c), each symbol is defined as follows.
R: Roll radius H: Entry thickness (thickness before entering the rolling mill for that pass)
h: Exit thickness (thickness when exiting the rolling mill of the pass)
　（中間焼鈍工程）
　中間焼鈍工程では、冷間圧延鋼板に対して中間焼鈍を行う。本実施形態では、中間焼鈍の温度を９００℃未満に制御する。中間焼鈍の温度は、８００℃以下とすることが好ましく、７５０℃以下とすることがより好ましい。中間焼鈍の温度が９００℃以上では、結晶粒の過度な粒成長に伴い、後述するスキンパス圧延および最終焼鈍を施しても｛４１１｝結晶方位への集積が進行しにくくなる。また、中間焼鈍の温度が低過ぎ十分な再結晶が生じないと、後述するスキンパス圧延および最終焼鈍を施しても｛４１１｝結晶方位を有する結晶粒の成長が阻害される。したがって、中間焼鈍の温度は６００℃以上とすることが好ましく、７００℃以上とすることがより好ましい。ここで説明する温度は連続焼鈍を前提としたものであり、中間焼鈍の時間は、５～１２０秒を好ましい範囲とする。この焼鈍温度域および焼鈍時間範囲は、冷間圧延工程までに少なからず生成している｛４１１｝結晶粒がバルジングにより適度に成長し、後述するスキンパス圧延および最終焼鈍を施すことで歪誘起粒成長を生じやすい状態にするために好適な条件になっていると考えられる。 (Intermediate annealing process)
In the intermediate annealing step, intermediate annealing is performed on the cold-rolled steel sheet. In this embodiment, the temperature of intermediate annealing is controlled to less than 900°C. The temperature of intermediate annealing is preferably 800°C or less, more preferably 750°C or less. If the temperature of intermediate annealing is 900°C or more, excessive grain growth of crystal grains will occur, and even if skin-pass rolling and final annealing are performed as described below, accumulation in the {411} crystal orientation will be difficult to proceed. In addition, if the temperature of intermediate annealing is too low and sufficient recrystallization does not occur, the growth of crystal grains having the {411} crystal orientation will be inhibited even if skin-pass rolling and final annealing are performed as described below. Therefore, the temperature of intermediate annealing is preferably 600°C or more, more preferably 700°C or more. The temperatures described here are based on continuous annealing, and the intermediate annealing time is preferably in the range of 5 to 120 seconds. It is believed that the annealing temperature range and annealing time range are suitable conditions for allowing the {411} crystal grains, which have already formed in no small amount by the cold rolling step, to grow appropriately by bulging, and for creating a state in which strain-induced grain growth is likely to occur by the skin-pass rolling and final annealing described below.
（スキンパス圧延工程）
　スキンパス圧延工程では、前記中間焼鈍工程後の鋼板に対してスキンパス圧延を行う。上述したようにバルジングによって｛４１１｝結晶方位が富化した状態でスキンパス圧延および焼鈍を行うと、｛４１１｝結晶方位を有する結晶粒がさらに成長する。これはスキンパス圧延により、｛４１１｝結晶方位を有する結晶粒には歪がたまりにくく、｛１１１｝＜１１２＞や｛１１１｝＜１１０＞などのγ－ｆｉｂｅｒと呼ばれる｛１１１｝面方位を有する方位群に属する結晶粒には歪がたまりやすい性質があり、その後の焼鈍で歪の少ない｛４１１｝結晶方位を有する結晶粒が歪の差を駆動力にこれらのγ－ｆｉｂｅｒ方位粒を蚕食するためである。歪差を駆動力にして発生するこの蚕食現象は歪誘起粒界移動（以下、ＳＩＢＭ）と呼ばれる。スキンパス圧延の圧下率は５％～２５％未満とすることが好ましい。圧下率が５％未満では歪量が少なすぎるため、この後の焼鈍で歪誘起粒界移動（以下、ＳＩＢＭ）が起きなくなり、｛４１１｝結晶方位を有する結晶粒は大きくならない。一方、圧下率が２５％以上では歪量が多くなり過ぎ、γ-ｆｉｂｅｒ方位を有する結晶粒の中から新しい結晶粒が生まれる再結晶核生成（以下Ｎｕｃｌｅａｔｉｏｎ）が発生する。このＮｕｃｌｅａｔｉｏｎではほとんどの生まれてくる粒がγ-ｆｉｂｅｒ方位を有する結晶粒のため、磁気特性が悪くなる。板面内の平均磁束密度を高くかつ異方性を小さくするという観点からは、スキンパス圧延の圧下率は５％～１５％とすることがより好ましい。 (Skin pass rolling process)
In the skin pass rolling process, the steel sheet after the intermediate annealing process is subjected to skin pass rolling. As described above, when skin pass rolling and annealing are performed in a state where the {411} crystal orientation is enriched by bulging, the crystal grains having the {411} crystal orientation grow further. This is because the crystal grains having the {411} crystal orientation are less likely to accumulate strain due to skin pass rolling, while the crystal grains belonging to the orientation group having the {111} plane orientation called γ-fiber, such as {111}<112> and {111}<110>, tend to accumulate strain, and the crystal grains having the {411} crystal orientation with less strain in the subsequent annealing use the difference in strain as a driving force to eat away at these γ-fiber orientation grains. This encroachment phenomenon that occurs with the difference in strain as a driving force is called strain induced grain boundary migration (hereinafter, SIBM). It is preferable that the reduction ratio of the skin pass rolling is 5% to less than 25%. If the reduction rate is less than 5%, the amount of strain is too small, so that the subsequent annealing does not cause strain-induced grain boundary migration (hereinafter, SIBM), and the crystal grains having the {411} crystal orientation do not become large. On the other hand, if the reduction rate is 25% or more, the amount of strain becomes too large, and recrystallization nucleation (hereinafter, nucleation) occurs, in which new crystal grains are born from crystal grains having the γ-fiber orientation. In this nucleation, most of the grains born are crystal grains having the γ-fiber orientation, so the magnetic properties become poor. From the viewpoint of increasing the average magnetic flux density in the sheet surface and reducing the anisotropy, it is more preferable to set the reduction rate of the skin pass rolling to 5% to 15%.
　なお、無方向性電磁鋼板において、前述した歪の分布を有するようにする場合には、スキンパス圧延時の圧下率（％）をＲＲ２とした場合に、５＜ＲＲ２＜２５を満たすように冷間圧延およびスキンパス圧延の圧下率を調整することが好ましい。 In addition, when non-oriented electrical steel sheet is to have the above-mentioned strain distribution, it is preferable to adjust the reduction ratios of cold rolling and skin pass rolling so as to satisfy 5 < RR2 < 25, where RR2 is the reduction ratio (%) during skin pass rolling.
　ここで、冷間圧延における圧下率ＲＲ１（％）は、次のとおり定義される。
　圧下率ＲＲ１（％）＝（１－冷間圧延での最終パスの圧延後の板厚／冷間圧延での１パス目の圧延前の板厚）×１００
　また、スキンパス圧延における圧下率ＲＲ２（％）は、次のとおり定義される。
　圧下率ＲＲ２（％）＝（１－スキンパス圧延での最終パスの圧延後の板厚／スキンパス圧延での１パス目の圧延前の板厚）×１００ Here, the reduction rate RR1 (%) in cold rolling is defined as follows.
Reduction rate RR1 (%) = (1 - thickness after the final pass of cold rolling / thickness before the first pass of cold rolling) x 100
The reduction ratio RR2 (%) in skin pass rolling is defined as follows.
Reduction rate RR2 (%) = (1 - thickness after the final pass of skin pass rolling / thickness before the first pass of skin pass rolling) x 100
（最終焼鈍工程）
　最終焼鈍工程では、前記スキンパス圧延後の鋼板に対して最終焼鈍を行う。この最終焼鈍により、スキンパス圧延による結晶方位毎の歪差を駆動力にしたＳＩＢＭが生じ、本開示が目的とする｛４１１｝結晶方位を有する結晶粒が優先的に成長し、鋼板の｛４１１｝結晶方位集積度が上昇する。この焼鈍条件は当業者であればＳＩＢＭの発生を確認しつつ適宜設定することが可能であり、特に限定するものではないが、一例として、連続焼鈍であれば７００～９５０℃で１～１００秒、バッチ焼鈍であれば６５０～８５０℃で０．５～２時間の焼鈍を挙げることができる。 (Final annealing process)
In the final annealing step, the steel sheet after the skin pass rolling is subjected to final annealing. This final annealing generates SIBM driven by the strain difference for each crystal orientation due to skin pass rolling, and crystal grains having the {411} crystal orientation targeted by the present disclosure grow preferentially, increasing the {411} crystal orientation concentration of the steel sheet. This annealing condition can be appropriately set by a person skilled in the art while confirming the occurrence of SIBM, and is not particularly limited, but examples include annealing at 700 to 950 ° C for 1 to 100 seconds in the case of continuous annealing and annealing at 650 to 850 ° C for 0.5 to 2 hours in the case of batch annealing.
　以上のように本実施形態に係る無方向性電磁鋼板を製造することができる。ただし、この製造方法は、本実施形態の無方向性電磁鋼板を製造する方法の一例であり、製造方法を限定するものではない。 The non-oriented electrical steel sheet according to this embodiment can be manufactured as described above. However, this manufacturing method is only one example of a method for manufacturing the non-oriented electrical steel sheet according to this embodiment, and is not intended to limit the manufacturing method.
　以上のように本実施形態に係る無方向性電磁鋼板を製造することができる。
　なお、最終焼鈍工程は、スキンパス圧延後に例えば鋼板製造メーカーにおいて鋼板コイルの状態で、または切板として実施することが可能である。または、スキンパス圧延後、最終焼鈍工程を行わずに出荷し、モータ製造メーカーで鋼板をモータコアとしての所定の形状に加工し、積層した後、コア形状で最終焼鈍を実施することも可能である。後者の場合は、一般的にモータ製造メーカーでモータコアに対して行われる「歪取焼鈍」を兼ねて実施できる。
　なお、最終焼鈍は鋼板製造メーカーとモータ製造メーカーの両方で、２回以上の最終焼鈍として実施しても良い。スキンパス圧延後の最終焼鈍を調整することで、歪の残存量、結晶粒径と｛４１１｝方位の発達の程度を調整できる。歪の残量量が多い、または結晶粒径が比較的小さい状態の鋼板は強度が高く、特にロータコア用の無方向性電磁鋼板として使用することで、コアの回転に伴う遠心力による変形を抑制するためにも好適となる。一方で、十分に歪を解放し結晶粒径を粗大とした鋼板は、特にステータコア用の無方向性電磁鋼板として使用することで、鉄損を抑制するために好適となる。 As described above, the non-oriented electrical steel sheet according to this embodiment can be manufactured.
The final annealing process can be performed after skin pass rolling, for example, at a steel sheet manufacturer in the form of a steel sheet coil or as a cut sheet. Alternatively, after skin pass rolling, the steel sheet can be shipped without undergoing the final annealing process, and the motor manufacturer can process the steel sheet into a predetermined shape as a motor core, laminate the steel sheet, and then perform final annealing in the core shape. In the latter case, this process can also be performed as "strain relief annealing" that is generally performed on motor cores at motor manufacturers.
The final annealing may be performed by both the steel sheet manufacturer and the motor manufacturer as two or more final annealings. By adjusting the final annealing after skin pass rolling, the remaining amount of strain, the grain size, and the degree of development of the {411} orientation can be adjusted. A steel sheet with a large amount of remaining strain or a relatively small grain size has high strength, and is particularly suitable for use as a non-oriented electrical steel sheet for a rotor core to suppress deformation due to centrifugal force accompanying the rotation of the core. On the other hand, a steel sheet with sufficient strain release and coarse grain size is particularly suitable for use as a non-oriented electrical steel sheet for a stator core to suppress iron loss.
　本実施形態に係る無方向性電磁鋼板からなる鉄鋼部材は、例えば回転電機の鉄心（モータコア）に適用される。この場合、本実施形態に係る無方向性電磁鋼板から個々の平板状薄板を切り出し、これらの平板状薄板を適宜積層することにより、回転電機に用いられる鉄心が作製される。この鉄心は、優れた磁気特性を有する無方向性電磁鋼板が適用されているために鉄損が低く抑えられており、優れたトルクを有する回転電機が実現する。本実施形態に係る無方向性電磁鋼板からなる鉄鋼部材は、回転電機の鉄心以外の製品、例えばリニアモータや静止機(リアクトルや変圧器)等の鉄心にも適用することができる。 The steel member made of the non-oriented electromagnetic steel sheet according to this embodiment is applied to, for example, the iron core (motor core) of a rotating electric machine. In this case, the iron core used in the rotating electric machine is produced by cutting out individual flat thin plates from the non-oriented electromagnetic steel sheet according to this embodiment and appropriately stacking these flat thin plates. This iron core uses non-oriented electromagnetic steel sheet with excellent magnetic properties, so iron loss is kept low, resulting in a rotating electric machine with excellent torque. The steel member made of the non-oriented electromagnetic steel sheet according to this embodiment can also be applied to products other than the iron core of a rotating electric machine, such as the iron core of a linear motor or a stationary machine (reactor or transformer).
　次に、本開示の実施形態に係る無方向性電磁鋼板について、実施例を示しながら具体的に説明する。以下に示す実施例は、本開示の実施形態に係る無方向性電磁鋼板のあくまでも一例にすぎず、本開示に係る無方向性電磁鋼板が下記の例に限定されるものではない。 Next, the non-oriented electrical steel sheet according to the embodiment of the present disclosure will be specifically described with reference to an example. The example shown below is merely one example of the non-oriented electrical steel sheet according to the embodiment of the present disclosure, and the non-oriented electrical steel sheet according to the present disclosure is not limited to the example below.
　溶鋼を鋳造することにより、以下の表１に示す成分のインゴットを作製した。なお、表１の「Ｃｏ等」は、Ｃｏ、Ｐｔ、Ｐｂ、Ａｕの各含有量を示す。その後、作製したインゴットに対して、表１に示す条件で、熱間圧延して熱間圧延板を得た。次に、表１に示す条件で、冷間圧延して冷間圧延板を得た。 The molten steel was cast to produce an ingot with the composition shown in Table 1 below. Note that "Co, etc." in Table 1 indicates the respective contents of Co, Pt, Pb, and Au. The produced ingot was then hot rolled under the conditions shown in Table 1 to obtain a hot-rolled sheet. Next, it was cold rolled under the conditions shown in Table 1 to obtain a cold-rolled sheet.
　上記冷間圧延板を、無酸化雰囲気中で表２に示す温度で中間焼鈍を３０秒行い、次いで、表２に示す圧下率で２回目の冷間圧延（スキンパス圧延）を行った。 The cold-rolled sheet was subjected to intermediate annealing in a non-oxidizing atmosphere at the temperature shown in Table 2 for 30 seconds, and then subjected to a second cold rolling (skin pass rolling) at the reduction ratio shown in Table 2.
　次に、集合組織を調査するため、鋼板の一部を切除し、その切除した試験片を７／８の厚みに減厚加工し、その加工面（鋼板を鋼板の板面側から１／８研磨した研磨面）について上述の要領でＥＢＳＤ観察(Ｓｔｅｐ間隔：０．３μｍ)を行った。ＥＢＳＤ観察により、表３に示す種類の方位粒の面積および平均ＫＡＭ値を求めた。 Next, to investigate the texture, a portion of the steel plate was cut out, the cut out test piece was processed to reduce its thickness to 7/8, and the processed surface (the polished surface where the steel plate was polished to 1/8 from the plate side) was observed with EBSD (step interval: 0.3 μm) as described above. From the EBSD observation, the area and average KAM value of the oriented grains of the types shown in Table 3 were determined.
　また、鋼板に最終焼鈍として、８００℃で２時間の焼鈍を行った。最終焼鈍後の鋼板から、測定試料として、５５ｍｍ角の試料片を採取した。この際に、試料片の一辺が圧延方向と平行になる試料と、圧延方向に対し４５度傾きを持つ試料を採取した。また、試料採取はせん断機を用いて実施した。
　次に、集合組織を調査するため、鋼板の一部を切除し、その切除した試験片を７／８の厚みに減厚加工し、その加工面（鋼板を鋼板の板面側から１／８研磨した研磨面）について上述の要領でＥＢＳＤ観察(Ｓｔｅｐ間隔：２．０μｍ)を行った。ＥＢＳＤ観察により、表３に示す種類の方位粒の面積および平均ＫＡＭ値を求めた。
　そして、圧延方向における磁束密度Ｂ５０Ｌ、圧延方向に対して４５°方向の磁束密度Ｂ５０Ｄ、圧延方向に対して９０°方向の磁束密度Ｂ５０ＣをＪＩＳＣ２５５６（２０１５）に準じて測定した。測定結果を表３に示す。なお、表３に示す「平均値」は、磁束密度Ｂ５０の全周平均値（圧延方向、圧延方向に対して９０°方向、圧延方向に対して４５°（１３５°）の方向の磁束密度Ｂ５０平均値）である。 The steel sheet was subjected to final annealing at 800° C. for 2 hours. From the steel sheet after final annealing, a 55 mm square sample was taken as a measurement sample. At this time, a sample in which one side of the sample piece was parallel to the rolling direction and a sample inclined at 45 degrees to the rolling direction were taken. The sample taking was performed using a shearing machine.
Next, in order to investigate the texture, a part of the steel sheet was cut out, the cut out test piece was processed to reduce the thickness to 7/8, and the processed surface (the polished surface obtained by polishing the steel sheet from the sheet surface side to 1/8) was observed by EBSD (step interval: 2.0 μm) in the above-mentioned manner. The areas and average KAM values of the orientation grains of the types shown in Table 3 were obtained by EBSD observation.
Then, the magnetic flux density B50L in the rolling direction, the magnetic flux density B50D in the 45° direction relative to the rolling direction, and the magnetic flux density B50C in the 90° direction relative to the rolling direction were measured in accordance with JIS C2556 (2015). The measurement results are shown in Table 3. The "average value" shown in Table 3 is the average value of the magnetic flux density B50 all around (the average value of the magnetic flux density B50 in the rolling direction, the 90° direction relative to the rolling direction, and the 45° (135°) direction relative to the rolling direction).
　また、圧延性について、次の通り評価した。冷延板コイルの最外周長手方向先端トップ部）から長手方向に１０ｍ位置、コイルの最外周長手方向先端からコイル長手方向全長に対して１／２長さ位置（ミドル部）、コイルの最内周長手方向先端（ボトム部）から長手方向に１０ｍ位置を中心とする、長手方向長さ１ｍの領域において、コイルの板幅方向両端面において長さ１ｃｍ以上の割れが合計２ヶ所以上生じている場合は「Ｎ」、それ以外を「Ｙ」とした。
　なお、本実施例では冷延板コイルを圧延性の評価対象としたが、冷延板コイルから切り出された鋼板を評価する場合は、鋼板長手方向（圧延方向）における３か所以上の異なる位置において、上記と同様に板幅方向両側端面を観察してもよい。例えば、鋼板の長手方向長さに対して約１／１０、１／２、９／１０位置を中心とする、鋼板の長手方向全長の約１／１０の範囲で観察すればよく、鋼板の長手方向全長は１ｍ以上とすればよい。 The rollability was evaluated as follows: In a 1 m long region centered on a position 10 m in the longitudinal direction from the outermost longitudinal tip of the cold-rolled sheet coil (top part), a position 1/2 the total length of the coil in the longitudinal direction from the outermost longitudinal tip of the coil (middle part), and a position 10 m in the longitudinal direction from the innermost longitudinal tip of the coil (bottom part), if cracks having a length of 1 cm or more were present in a total of two or more places on both end faces in the sheet width direction of the coil, the evaluation was given as "N", and otherwise as "Y".
In this embodiment, the cold-rolled coil was used as the evaluation target for rollability, but when evaluating a steel sheet cut out from a cold-rolled coil, both end faces in the sheet width direction may be observed in three or more different positions in the longitudinal direction (rolling direction) of the steel sheet in the same manner as described above. For example, it is sufficient to observe in a range of about 1/10 of the entire longitudinal length of the steel sheet, centered at positions of about 1/10, 1/2, and 9/10 of the longitudinal length of the steel sheet, and the entire longitudinal length of the steel sheet may be 1 m or more.
　なお、Ｎｏ．１２の鋼板については、試験片を１／２の厚みに減厚加工し、その加工面について上述の要領でＥＢＳＤ観察を行って、表４に示す種類の方位粒の面積および平均ＫＡＭ値を求めた。その結果を、磁気特性及び圧延性と共に表４に示す。 For steel sheet No. 12, the test piece was processed to reduce its thickness to half, and the processed surface was observed by EBSD in the manner described above to determine the area and average KAM value of the oriented grains of the types shown in Table 4. The results are shown in Table 4 together with the magnetic properties and rolling properties.
　本開示によれば、板面内異方性が小さく全周平均（全方向平均）で優れた磁気特性を有する無方向性電磁鋼板を提供できるため、産業上極めて有用である。 This disclosure makes it possible to provide non-oriented electrical steel sheets that have small in-plane anisotropy and excellent magnetic properties on average around the circumference (average in all directions), making them extremely useful in industry.
　なお、日本国特許出願第２０２３－００１９３５号の開示はその全体が参照により本明細書に取り込まれる。
　本明細書に記載された全ての文献、特許出願、および技術規格は、個々の文献、特許出願、および技術規格が参照により取り込まれることが具体的かつ個々に記された場合と同程度に、本明細書中に参照により取り込まれる。 The disclosure of Japanese Patent Application No. 2023-001935 is incorporated herein by reference in its entirety.
All publications, patent applications, and standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or standard was specifically and individually indicated to be incorporated by reference.

Claims (4)

  1. 　質量％で、
    　Ｃ　：０．０１００％以下、
    　Ｓｉ：１．５０％～４．００％、
    　ｓｏｌ．Ａｌ：０．０００１％～１．０％、
    　Ｓ　：０．０１００％以下、
    　Ｎ　：０．０１００％以下、
    　Ｍｎ：０．１０％以上、
    　Ｍｎ、Ｎｉ、及びＣｕから選ばれる１種又は複数種：総計で２．５０％未満、
    　Ｍｏ：０．０％～２．５％未満、
    　Ｃｒ：０．０％～２．５％未満、
    　Ｔｉ：０．０００％～０．００５％、
    　Ｎｂ：０．０００％～０．００５％、
    　Ｓｎ：０．０００％～０．４００％、
    　Ｓｂ：０．０００％～０．４００％、
    　Ｐ　：０．０００％～０．４００％、及び
    　Ｍｇ、Ｃａ、Ｓｒ、Ｂａ、Ｃｅ、Ｌａ、Ｎｄ、Ｐｒ、Ｚｎ、及びＣｄからなる群から選ばれる１種又は複数種：総計で０．００００％～０．０１００％を含有し、
    質量％での、Ｃ含有量を［Ｃ］、Ｍｏ含有量を［Ｍｏ］、Ｃｒ含有量を［Ｃｒ］、Ｍｎ含有量を［Ｍｎ］、Ｎｉ含有量を［Ｎｉ］、Ｃｕ含有量を［Ｃｕ］、Ｓｉ含有量を［Ｓｉ］、ｓｏｌ．Ａｌ含有量を［ｓｏｌ．Ａｌ］、Ｐ含有量を［Ｐ］としたときに、以下の（１）式で定めた変態温度Ａｒ３（℃）が７５０～１０５０℃であり、残部がＦｅおよび不純物からなる化学組成を有し、
    　さらに、鋼板表面に平行な面でＥＢＳＤにより観察したときにおいて、全面積をＳtot、｛４１１｝方位粒の面積をＳ411、｛１００｝方位粒の面積をＳ100、以下の（２）式に従うテイラー因子Ｍが２．９超となる方位粒の面積をＳtyl、前記テイラー因子Ｍが２．９以下となる方位粒の合計面積をＳtra、｛４１１｝方位粒の平均ＫＡＭ値をＫ411、前記テイラー因子Ｍが２．９超となる方位粒の平均ＫＡＭ値をＫtylとした場合に、以下の（３）式及び（４）式～（７）式を満たす無方向性電磁鋼板。
    　Ａｒ３（℃）＝１０２０－３２５×［Ｃ］＋３３×［Ｓｉ］＋２８７×［Ｐ］＋８０×［ｓｏｌ．Ａｌ］－１２０×（［Ｍｎ］＋［Ｍｏ］＋［Ｃｕ］）－４６×（［Ｃｒ］＋［Ｎｉ］）　　　・・・（１）
    　Ｍ＝（cosφ×cosλ）-1　　　・・・（２）
    　Ｓ411／Ｓ100＞１．００　　　・・・（３）
    　０．２０≦Ｓtyl／Ｓtot≦０．８５　　　・・・（４）
    　０．０５≦Ｓ411／Ｓtot≦０．８０　　　・・・（５）
    　Ｓ411／Ｓtra≧０．５０　　　・・・（６）
    　Ｋ411／Ｋtyl≦０．９９０　　　・・・（７）
    　ここで、（２）式中のφは応力ベクトルと結晶のすべり方向ベクトルのなす角を表し、λは応力ベクトルと結晶のすべり面の法線ベクトルのなす角を表す。     In mass percent,
    C: 0.0100% or less,
    Si: 1.50% to 4.00%,
    sol. Al: 0.0001% to 1.0%,
    S: 0.0100% or less,
    N: 0.0100% or less,
    Mn: 0.10% or more,
    One or more selected from Mn, Ni, and Cu: less than 2.50% in total;
    Mo: 0.0% to less than 2.5%
    Cr: 0.0% to less than 2.5%
    Ti: 0.000% to 0.005%,
    Nb: 0.000% to 0.005%,
    Sn: 0.000% to 0.400%,
    Sb: 0.000% to 0.400%,
    P: 0.000% to 0.400%, and one or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total;
    The alloy has a chemical composition in which the transformation temperature Ar 3 (°C) defined by the following formula (1) is 750 to 1050°C, with the balance being Fe and impurities, where the C content is [C], the Mo content is [Mo], the Cr content is [ Cr], the Mn content is [Mn], the Ni content is [Ni], the Cu content is [Cu], the Si content is [Si], the sol. Al content is [sol. Al], and the P content is [P], in mass %,
    Furthermore, when observed by EBSD on a plane parallel to the steel sheet surface, the non-oriented electrical steel sheet satisfies the following formulas (3) and (4) to (7), where the total area is S tot , the area of {411} oriented grains is S 411 , the area of {100} oriented grains is S 100 , the area of oriented grains having a Taylor factor M according to the following formula (2) of more than 2.9 is S tyl , the total area of oriented grains having the Taylor factor M of 2.9 or less is S tra , the average KAM value of the {411} oriented grains is K 411 , and the average KAM value of the oriented grains having the Taylor factor M of more than 2.9 is K tyl .
    Ar 3 (°C)=1020-325×[C]+33×[Si]+287×[P]+80×[sol. Al]-120×([Mn]+[Mo]+[Cu])-46×([Cr]+[Ni])...(1)
    M=(cosφ×cosλ) -1 ...(2)
    S 411 /S 100 >1.00...(3)
    0.20≦S tyl /S tot ≦0.85 (4)
    0.05≦S 411 /S tot ≦0.80 (5)
    S411 / Stra ≧0.50...(6)
    K 411 /K tyl ≦0.990 (7)
    Here, in formula (2), φ represents the angle between the stress vector and the slip direction vector of the crystal, and λ represents the angle between the stress vector and the normal vector of the slip plane of the crystal.
  2. 　質量％で、
    　Ｃ　：０．０１００％以下、
    　Ｓｉ：１．５０％～４．００％、
    　ｓｏｌ．Ａｌ：０．０００１％～１．０％、
    　Ｓ　：０．０１００％以下、
    　Ｎ　：０．０１００％以下、
    　Ｍｎ：０．１０％以上、
    　Ｍｎ、Ｎｉ、Ｃｏ、Ｐｔ、Ｐｂ、Ａｕ、及びＣｕから選ばれる１種又は複数種：総計で２．５０％未満、
    　Ｍｏ：０．０％～２．５％未満、
    　Ｃｒ：０．０％～２．５％未満、
    　Ｔｉ：０．０００％～０．００５％、
    　Ｎｂ：０．０００％～０．００５％、
    　Ｓｎ：０．０００％～０．４００％、
    　Ｓｂ：０．０００％～０．４００％、
    　Ｐ　：０．０００％～０．４００％、及び
    　Ｍｇ、Ｃａ、Ｓｒ、Ｂａ、Ｃｅ、Ｌａ、Ｎｄ、Ｐｒ、Ｚｎ、及びＣｄからなる群から選ばれる１種又は複数種：総計で０．００００％～０．０１００％を含有し、
    質量％での、Ｃ含有量を［Ｃ］、Ｍｏ含有量を［Ｍｏ］、Ｃｒ含有量を［Ｃｒ］、Ｍｎ含有量を［Ｍｎ］、Ｎｉ含有量を［Ｎｉ］、Ｃｕ含有量を［Ｃｕ］、Ｓｉ含有量を［Ｓｉ］、ｓｏｌ．Ａｌ含有量を［ｓｏｌ．Ａｌ］、Ｐ含有量を［Ｐ］としたときに、以下の（１）式で定めた変態温度Ａｒ３（℃）が７５０～１０５０℃であり、残部がＦｅおよび不純物からなる化学組成を有し、
    　さらに、鋼板表面に平行な面でＥＢＳＤにより観察したときにおいて、全面積をＳtot、｛４１１｝方位粒の面積をＳ411、｛１００｝方位粒の面積をＳ100、以下の（２）式に従うテイラー因子Ｍが２．９超となる方位粒の面積をＳtyl、前記テイラー因子Ｍが２．９以下となる方位粒の合計面積をＳtra、｛４１１｝方位粒の平均ＫＡＭ値をＫ411、前記テイラー因子Ｍが２．９超となる方位粒の平均ＫＡＭ値をＫtylとした場合に、以下の（３）式及び（４）式～（７）式を満たす無方向性電磁鋼板。
    　Ａｒ３（℃）＝１０２０－３２５×［Ｃ］＋３３×［Ｓｉ］＋２８７×［Ｐ］＋８０×［ｓｏｌ．Ａｌ］－１２０×（［Ｍｎ］＋［Ｍｏ］＋［Ｃｕ］）－４６×（［Ｃｒ］＋［Ｎｉ］）　　　・・・（１）
    　Ｍ＝（cosφ×cosλ）-1　　　・・・（２）
    　Ｓ411／Ｓ100＞１．００　　　・・・（３）
    　０．２０≦Ｓtyl／Ｓtot≦０．８５　　　・・・（４）
    　０．０５≦Ｓ411／Ｓtot≦０．８０　　　・・・（５）
    　Ｓ411／Ｓtra≧０．５０　　　・・・（６）
    　Ｋ411／Ｋtyl≦０．９９０　　　・・・（７）
    　ここで、（２）式中のφは応力ベクトルと結晶のすべり方向ベクトルのなす角を表し、λは応力ベクトルと結晶のすべり面の法線ベクトルのなす角を表す。     In mass percent,
    C: 0.0100% or less,
    Si: 1.50% to 4.00%,
    sol. Al: 0.0001% to 1.0%,
    S: 0.0100% or less,
    N: 0.0100% or less,
    Mn: 0.10% or more,
    One or more selected from Mn, Ni, Co, Pt, Pb, Au, and Cu: less than 2.50% in total;
    Mo: 0.0% to less than 2.5%
    Cr: 0.0% to less than 2.5%
    Ti: 0.000% to 0.005%,
    Nb: 0.000% to 0.005%,
    Sn: 0.000% to 0.400%,
    Sb: 0.000% to 0.400%,
    P: 0.000% to 0.400%, and one or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total;
    The alloy has a chemical composition in which the transformation temperature Ar 3 (°C) defined by the following formula (1) is 750 to 1050°C, with the balance being Fe and impurities, where the C content is [C], the Mo content is [Mo], the Cr content is [ Cr], the Mn content is [Mn], the Ni content is [Ni], the Cu content is [Cu], the Si content is [Si], the sol. Al content is [sol. Al], and the P content is [P], in mass %,
    Furthermore, when observed by EBSD on a plane parallel to the steel sheet surface, the non-oriented electrical steel sheet satisfies the following formulas (3) and (4) to (7), where the total area is S tot , the area of {411} oriented grains is S 411 , the area of {100} oriented grains is S 100 , the area of oriented grains having a Taylor factor M according to the following formula (2) of more than 2.9 is S tyl , the total area of oriented grains having the Taylor factor M of 2.9 or less is S tra , the average KAM value of the {411} oriented grains is K 411 , and the average KAM value of the oriented grains having the Taylor factor M of more than 2.9 is K tyl .
    Ar 3 (°C)=1020-325×[C]+33×[Si]+287×[P]+80×[sol. Al]-120×([Mn]+[Mo]+[Cu])-46×([Cr]+[Ni])...(1)
    M=(cosφ×cosλ) -1 ...(2)
    S 411 /S 100 >1.00...(3)
    0.20≦S tyl /S tot ≦0.85 (4)
    0.05≦S 411 /S tot ≦0.80 (5)
    S 411 /S tra ≧0.50 (6)
    K 411 /K tyl ≦0.990 (7)
    Here, in formula (2), φ represents the angle between the stress vector and the slip direction vector of the crystal, and λ represents the angle between the stress vector and the normal vector of the slip plane of the crystal.
  3. 　質量％で、
    　Ｃ　：０．０１００％以下、
    　Ｓｉ：１．５０％～４．００％、
    　ｓｏｌ．Ａｌ：０．０００１％～１．０％、
    　Ｓ　：０．０１００％以下、
    　Ｎ　：０．０１００％以下、
    　Ｍｎ：０．１０％以上、
    　Ｍｎ、Ｎｉ、及びＣｕから選ばれる１種又は複数種：総計で２．５０％未満、
    　Ｍｏ：０．０％～２．５％未満、
    　Ｃｒ：０．０％～２．５％未満、
    　Ｔｉ：０．０００％～０．００５％、
    　Ｎｂ：０．０００％～０．００５％、
    　Ｓｎ：０．０００％～０．４００％、
    　Ｓｂ：０．０００％～０．４００％、
    　Ｐ　：０．０００％～０．４００％、及び 
    　Ｍｇ、Ｃａ、Ｓｒ、Ｂａ、Ｃｅ、Ｌａ、Ｎｄ、Ｐｒ、Ｚｎ、及びＣｄからなる群から選ばれる１種又は複数種：総計で０．００００％～０．０１００％を含有し、
    質量％での、Ｃ含有量を［Ｃ］、Ｍｏ含有量を［Ｍｏ］、Ｃｒ含有量を［Ｃｒ］、Ｍｎ含有量を［Ｍｎ］、Ｎｉ含有量を［Ｎｉ］、Ｃｕ含有量を［Ｃｕ］、Ｓｉ含有量を［Ｓｉ］、ｓｏｌ．Ａｌ含有量を［ｓｏｌ．Ａｌ］、Ｐ含有量を［Ｐ］としたときに、以下の（１）式で定めた変態温度Ａｒ３（℃）が７５０～１０５０℃であり、残部がＦｅおよび不純物からなる化学組成を有し、
    　さらに、鋼板表面に平行な面でＥＢＳＤにより観察したときにおいて、全面積をＳtot、｛４１１｝方位粒の面積をＳ411、｛１００｝方位粒の面積をＳ100、以下の（２）式に従うテイラー因子Ｍが２．９超となる方位粒の面積をＳtyl、前記テイラー因子Ｍが２．９以下となる方位粒の合計面積をＳtraとした場合に、以下の（８）式～（１１）式を満たす無方向性電磁鋼板。
    　Ａｒ３（℃）＝１０２０－３２５×［Ｃ］＋３３×［Ｓｉ］＋２８７×［Ｐ］＋８０×［ｓｏｌ．Ａｌ］－１２０×（［Ｍｎ］＋［Ｍｏ］＋［Ｃｕ］）－４６×（［Ｃｒ］＋［Ｎｉ］）　　　・・・（１）
    　Ｍ＝（cosφ×cosλ）-1　　　・・・（２）
    　Ｓ411／Ｓ100＞２．００　　　・・・（８）
    　Ｓtyl／Ｓtot＜０．５５　　　・・・（９）
    　Ｓ411／Ｓtot＞０．３０　　　・・・（１０）
    　Ｓ411／Ｓtra≧０．６０　　　・・・（１１）
    　ここで、（２）式中のφは応力ベクトルと結晶のすべり方向ベクトルのなす角を表し、λは応力ベクトルと結晶のすべり面の法線ベクトルのなす角を表す。     In mass percent,
    C: 0.0100% or less,
    Si: 1.50% to 4.00%,
    sol. Al: 0.0001% to 1.0%,
    S: 0.0100% or less,
    N: 0.0100% or less,
    Mn: 0.10% or more,
    One or more selected from Mn, Ni, and Cu: less than 2.50% in total;
    Mo: 0.0% to less than 2.5%
    Cr: 0.0% to less than 2.5%
    Ti: 0.000% to 0.005%,
    Nb: 0.000% to 0.005%,
    Sn: 0.000% to 0.400%,
    Sb: 0.000% to 0.400%,
    P: 0.000% to 0.400%, and
    One or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total;
    The alloy has a chemical composition in which the transformation temperature Ar 3 (°C) defined by the following formula (1) is 750 to 1050°C, with the balance being Fe and impurities, where the C content is [C], the Mo content is [Mo], the Cr content is [ Cr], the Mn content is [Mn], the Ni content is [Ni], the Cu content is [Cu], the Si content is [Si], the sol. Al content is [sol. Al], and the P content is [P], in mass %,
    Furthermore, when observed by EBSD on a plane parallel to the steel sheet surface, the non-oriented electrical steel sheet satisfies the following formulas (8) to (11), where the total area is S tot , the area of {411} oriented grains is S 411 , the area of {100} oriented grains is S 100 , the area of oriented grains having a Taylor factor M according to the following formula (2) exceeding 2.9 is S tyl , and the total area of oriented grains having the Taylor factor M of 2.9 or less is S tra .
    Ar 3 (°C)=1020-325×[C]+33×[Si]+287×[P]+80×[sol. Al]-120×([Mn]+[Mo]+[Cu])-46×([Cr]+[Ni])...(1)
    M=(cosφ×cosλ) -1 ...(2)
    S 411 /S 100 >2.00...(8)
    S tyl /S tot <0.55...(9)
    S 411 /S tot >0.30...(10)
    S 411 /S tra ≧0.60 (11)
    Here, in formula (2), φ represents the angle between the stress vector and the slip direction vector of the crystal, and λ represents the angle between the stress vector and the normal vector of the slip plane of the crystal.
  4. 　質量％で、
    　Ｃ　：０．０１００％以下、
    　Ｓｉ：１．５０％～４．００％、
    　ｓｏｌ．Ａｌ：０．０００１％～１．０％、
    　Ｓ　：０．０１００％以下、
    　Ｎ　：０．０１００％以下、
    　Ｍｎ：０．１０％以上、
    　Ｍｎ、Ｎｉ、Ｃｏ、Ｐｔ、Ｐｂ、Ａｕ、及びＣｕから選ばれる１種又は複数種：総計で２．５０％未満、
    　Ｍｏ：０．０％～２．５％未満、
    　Ｃｒ：０．０％～２．５％未満、
    　Ｔｉ：０．０００％～０．００５％、
    　Ｎｂ：０．０００％～０．００５％、
    　Ｓｎ：０．０００％～０．４００％、
    　Ｓｂ：０．０００％～０．４００％、
    　Ｐ　：０．０００％～０．４００％、及び
    　Ｍｇ、Ｃａ、Ｓｒ、Ｂａ、Ｃｅ、Ｌａ、Ｎｄ、Ｐｒ、Ｚｎ、及びＣｄからなる群から選ばれる１種又は複数種：総計で０．００００％～０．０１００％を含有し、
    質量％での、Ｃ含有量を［Ｃ］、Ｍｏ含有量を［Ｍｏ］、Ｃｒ含有量を［Ｃｒ］、Ｍｎ含有量を［Ｍｎ］、Ｎｉ含有量を［Ｎｉ］、Ｃｕ含有量を［Ｃｕ］、Ｓｉ含有量を［Ｓｉ］、ｓｏｌ．Ａｌ含有量を［ｓｏｌ．Ａｌ］、Ｐ含有量を［Ｐ］としたときに、以下の（１）式で定めた変態温度Ａｒ３（℃）が７５０～１０５０℃であり、残部がＦｅおよび不純物からなる化学組成を有し、
    　さらに、鋼板表面に平行な面でＥＢＳＤにより観察したときにおいて、全面積をＳtot、｛４１１｝方位粒の面積をＳ411、｛１００｝方位粒の面積をＳ100、以下の（２）式に従うテイラー因子Ｍが２．９超となる方位粒の面積をＳtyl、前記テイラー因子Ｍが２．９以下となる方位粒の合計面積をＳtraとした場合に、以下の（８）式～（１１）式を満たす無方向性電磁鋼板。
    　Ａｒ３（℃）＝１０２０－３２５×［Ｃ］＋３３×［Ｓｉ］＋２８７×［Ｐ］＋８０×
    ［ｓｏｌ．Ａｌ］－１２０×（［Ｍｎ］＋［Ｍｏ］＋［Ｃｕ］）－４６×（［Ｃｒ］＋［Ｎｉ］）　　　・・・（１）
    　Ｍ＝（cosφ×cosλ）-1　　　・・・（２）
    　Ｓ411／Ｓ100＞２．００　　　・・・（８）
    　Ｓtyl／Ｓtot＜０．５５　　　・・・（９）
    　Ｓ411／Ｓtot＞０．３０　　　・・・（１０）
    　Ｓ411／Ｓtra≧０．６０　　　・・・（１１）
    　ここで、（２）式中のφは応力ベクトルと結晶のすべり方向ベクトルのなす角を表し、λは応力ベクトルと結晶のすべり面の法線ベクトルのなす角を表す。     In mass percent,
    C: 0.0100% or less,
    Si: 1.50% to 4.00%,
    sol. Al: 0.0001% to 1.0%,
    S: 0.0100% or less,
    N: 0.0100% or less,
    Mn: 0.10% or more,
    One or more selected from Mn, Ni, Co, Pt, Pb, Au, and Cu: less than 2.50% in total;
    Mo: 0.0% to less than 2.5%
    Cr: 0.0% to less than 2.5%
    Ti: 0.000% to 0.005%,
    Nb: 0.000% to 0.005%,
    Sn: 0.000% to 0.400%,
    Sb: 0.000% to 0.400%,
    P: 0.000% to 0.400%, and one or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total;
    The alloy has a chemical composition in which the transformation temperature Ar 3 (°C) defined by the following formula (1) is 750 to 1050°C, with the balance being Fe and impurities, where the C content is [C], the Mo content is [Mo], the Cr content is [ Cr], the Mn content is [Mn], the Ni content is [Ni], the Cu content is [Cu], the Si content is [Si], the sol. Al content is [sol. Al], and the P content is [P], in mass %,
    Furthermore, when observed by EBSD on a plane parallel to the steel sheet surface, the non-oriented electrical steel sheet satisfies the following formulas (8) to (11), where the total area is S tot , the area of {411} oriented grains is S 411 , the area of {100} oriented grains is S 100 , the area of oriented grains having a Taylor factor M according to the following formula (2) exceeding 2.9 is S tyl , and the total area of oriented grains having the Taylor factor M of 2.9 or less is S tra .
    Ar 3 (℃)=1020-325×[C]+33×[Si]+287×[P]+80×
    [sol. Al]-120×([Mn]+[Mo]+[Cu])-46×([Cr]+[Ni])...(1)
    M=(cosφ×cosλ) -1 ...(2)
    S 411 /S 100 >2.00...(8)
    S tyl /S tot <0.55...(9)
    S 411 /S tot >0.30...(10)
    S 411 /S tra ≧0.60 (11)
    Here, in formula (2), φ represents the angle between the stress vector and the slip direction vector of the crystal, and λ represents the angle between the stress vector and the normal vector of the slip plane of the crystal.
PCT/JP2024/000133 2023-01-10 2024-01-09 Non-oriented electromagnetic steel sheet WO2024150732A1 (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020153387A1 (en) * 2019-01-24 2020-07-30 Ｊｆｅスチール株式会社 Non-oriented electromagnetic steel sheet and method for producing same
JP2020139198A (en) * 2019-02-28 2020-09-03 日本製鉄株式会社 Non-oriented electromagnetic steel sheet
JP2021134383A (en) * 2020-02-26 2021-09-13 日本製鉄株式会社 Non-oriented electromagnetic steel sheet
WO2022196805A1 (en) * 2021-03-19 2022-09-22 日本製鉄株式会社 Non-directional electromagnetic steel sheet and method for manufacturing same
WO2022211007A1 (en) * 2021-04-02 2022-10-06 日本製鉄株式会社 Non-oriented electrical steel sheet
KR20230094459A (en) * 2021-12-21 2023-06-28 주식회사 포스코 Non-oriented electrical steel sheet and method for manufacturing the same

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020153387A1 (en) * 2019-01-24 2020-07-30 Ｊｆｅスチール株式会社 Non-oriented electromagnetic steel sheet and method for producing same
JP2020139198A (en) * 2019-02-28 2020-09-03 日本製鉄株式会社 Non-oriented electromagnetic steel sheet
JP2021134383A (en) * 2020-02-26 2021-09-13 日本製鉄株式会社 Non-oriented electromagnetic steel sheet
WO2022196805A1 (en) * 2021-03-19 2022-09-22 日本製鉄株式会社 Non-directional electromagnetic steel sheet and method for manufacturing same
WO2022211007A1 (en) * 2021-04-02 2022-10-06 日本製鉄株式会社 Non-oriented electrical steel sheet
KR20230094459A (en) * 2021-12-21 2023-06-28 주식회사 포스코 Non-oriented electrical steel sheet and method for manufacturing the same

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