EP2757165B1 - Method of producing grain-oriented electrical steel sheet having excellent iron loss properties - Google Patents
Method of producing grain-oriented electrical steel sheet having excellent iron loss properties Download PDFInfo
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- EP2757165B1 EP2757165B1 EP12832398.7A EP12832398A EP2757165B1 EP 2757165 B1 EP2757165 B1 EP 2757165B1 EP 12832398 A EP12832398 A EP 12832398A EP 2757165 B1 EP2757165 B1 EP 2757165B1
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- 238000000034 method Methods 0.000 title claims description 26
- 229910001224 Grain-oriented electrical steel Inorganic materials 0.000 title claims description 23
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title description 56
- 229910052742 iron Inorganic materials 0.000 title description 27
- 238000010438 heat treatment Methods 0.000 claims description 99
- 238000001953 recrystallisation Methods 0.000 claims description 93
- 238000000137 annealing Methods 0.000 claims description 87
- 229910000831 Steel Inorganic materials 0.000 claims description 47
- 239000010959 steel Substances 0.000 claims description 47
- 238000005097 cold rolling Methods 0.000 claims description 24
- 229910052757 nitrogen Inorganic materials 0.000 claims description 13
- 239000000203 mixture Substances 0.000 claims description 10
- 239000000126 substance Substances 0.000 claims description 10
- 229910052717 sulfur Inorganic materials 0.000 claims description 9
- 229910052711 selenium Inorganic materials 0.000 claims description 8
- 238000005098 hot rolling Methods 0.000 claims description 6
- 229910052787 antimony Inorganic materials 0.000 claims description 4
- 229910052804 chromium Inorganic materials 0.000 claims description 4
- 229910052748 manganese Inorganic materials 0.000 claims description 4
- 229910052759 nickel Inorganic materials 0.000 claims description 4
- 229910052758 niobium Inorganic materials 0.000 claims description 4
- 229910052718 tin Inorganic materials 0.000 claims description 4
- 229910052719 titanium Inorganic materials 0.000 claims description 4
- 229910052797 bismuth Inorganic materials 0.000 claims description 3
- 239000012535 impurity Substances 0.000 claims description 3
- 229910052750 molybdenum Inorganic materials 0.000 claims description 3
- 229910052698 phosphorus Inorganic materials 0.000 claims description 3
- 238000011084 recovery Methods 0.000 description 19
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 18
- 238000005261 decarburization Methods 0.000 description 17
- 230000000694 effects Effects 0.000 description 16
- 230000000052 comparative effect Effects 0.000 description 15
- 239000011248 coating agent Substances 0.000 description 14
- 238000000576 coating method Methods 0.000 description 14
- 230000002708 enhancing effect Effects 0.000 description 12
- 239000013078 crystal Substances 0.000 description 11
- 230000001965 increasing effect Effects 0.000 description 10
- 238000001556 precipitation Methods 0.000 description 10
- 238000012360 testing method Methods 0.000 description 10
- 239000000047 product Substances 0.000 description 9
- 238000007670 refining Methods 0.000 description 7
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 6
- 239000000835 fiber Substances 0.000 description 6
- 239000003112 inhibitor Substances 0.000 description 6
- 238000009413 insulation Methods 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 238000011282 treatment Methods 0.000 description 6
- 238000007796 conventional method Methods 0.000 description 5
- 238000005096 rolling process Methods 0.000 description 5
- 229910052839 forsterite Inorganic materials 0.000 description 4
- HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 description 4
- 230000005381 magnetic domain Effects 0.000 description 4
- 239000002244 precipitate Substances 0.000 description 4
- 230000001603 reducing effect Effects 0.000 description 4
- 229910019142 PO4 Inorganic materials 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000006185 dispersion Substances 0.000 description 3
- 150000004767 nitrides Chemical class 0.000 description 3
- 230000001590 oxidative effect Effects 0.000 description 3
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 3
- 239000010452 phosphate Substances 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- YRKCREAYFQTBPV-UHFFFAOYSA-N acetylacetone Chemical compound CC(=O)CC(C)=O YRKCREAYFQTBPV-UHFFFAOYSA-N 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 229910052593 corundum Inorganic materials 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000001376 precipitating effect Effects 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 229910001845 yogo sapphire Inorganic materials 0.000 description 2
- 229910000976 Electrical steel Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910000565 Non-oriented electrical steel Inorganic materials 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 239000008119 colloidal silica Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 238000000866 electrolytic etching Methods 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000005121 nitriding Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000002829 reductive effect Effects 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- 238000005221 zone crystallization Methods 0.000 description 1
Images
Classifications
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- 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
- C21D8/1244—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the heat treatment(s) being of interest
- C21D8/1261—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the heat treatment(s) being of interest following hot rolling
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- 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
- C21D8/1244—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the heat treatment(s) being of interest
- C21D8/1272—Final recrystallisation annealing
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/008—Ferrous alloys, e.g. steel alloys containing tin
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/34—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of silicon
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- 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
- H01F1/16—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 in the form of sheets
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2201/00—Treatment for obtaining particular effects
- C21D2201/05—Grain orientation
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- 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
- C21D8/1216—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the working step(s) being of interest
- C21D8/1222—Hot rolling
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- 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
- C21D8/1216—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the working step(s) being of interest
- C21D8/1233—Cold rolling
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- 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
- C21D8/1244—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the heat treatment(s) being of interest
- C21D8/1266—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the heat treatment(s) being of interest between cold rolling steps
Definitions
- This invention relates to a method of producing a grain-oriented electrical steel sheet, and more particularly to a method of producing a grain-oriented electrical steel sheet being excellent in the iron loss properties throughout the whole length of a product coil.
- the grain-oriented electrical steel sheet is a soft magnetic material where its crystal orientation is highly oriented in the Goss orientation ( ⁇ 110 ⁇ ⁇ 001>) and is mainly used as cores for transformers or the like.
- the grain-oriented electrical steel sheet used in the transformer is required to have low iron loss W 17/50 (W/kg) representing magnetic loss when being magnetized to 1.7 T at a frequency of 50 Hz in order to reduce no-load loss (energy loss).
- the iron loss of the electrical steel sheet is represented as the sum of hysteresis loss depending on crystal orientation, purity and the like and eddy-current loss depending on specific resistance, sheet thickness, magnetic domain size and the like. Therefore, as a method for reducing the iron loss are known a method of enhancing an accumulation degree of crystal orientation to improve a magnetic flux density, a method of increasing Si content for enhancing an electric resistance, a method of reducing a thickness of a steel sheet, a method of refining secondary recrystallized grains, a method of refining magnetic domain and so on.
- Patent Document 1 discloses that the grain-oriented electrical steel sheet having extremely low iron loss can be obtained by heating the steel sheet rolled to a final thickness to a temperature of not lower than 700°C at a heating rate of not less than 100°C/sec in a non-oxidizing atmosphere having PH 2 O/PH 2 of not more than 0.2 just before decarburization annealing
- Patent Document 2 discloses that the grain-oriented electrical steel sheet having extremely low iron loss can be obtained by rapidly heating the steel sheet rolled to a final thickness to 800 ⁇ 950°C at a heating rate of not less than 100°C/sec in an atmosphere having an oxygen concentration of not more than 500 ppm before the decarburization annealing, and conducting decarburization annealing wherein a temperature of a preceding zone at the decarburization annealing step is 775 ⁇ 840°C lower than a temperature achieved by the rapid-heating and a temperature of subsequent latter zone is 815-875 °C higher than the temperature of the preceding zone.
- Patent Documents 3 and 4 disclose that grain-oriented electrical steel sheets being excellent in the film properties and magnetic properties can be obtained by heating a temperature zone of at least not less than 600°C at a heating stage of decarburization annealing step to not lower than 800°C at a heating rate of not less than 95°C/s or not less than 100°C/s and properly controlling an atmosphere of this temperature zone.
- Patent Document 5 relates to a method for stably achieving a good iron loss reducing effect by rapid heating treatment of a steel sheet in a case where primary recrystallization annealing including rapid heating treatment is carried out in a method for manufacturing a grain oriented electrical steel sheet using an inhibitor-free material.
- the invention is made in view of the above problems inherent to the conventional techniques and is to propose a method of producing a grain-oriented electrical steel sheet which is capable of stabilizing secondary recrystallization behavior to refine secondary recrystallized grains over a full length of a product coil to thereby make the iron loss of the full length of the product coil lower.
- low temperature zone a relatively low temperature zone mainly enhancing only the recovery
- high temperature zone a relatively high temperature zone enhancing both of the recovery and the recrystallization
- the invention is a method of producing a grain-oriented electrical steel sheet which comprises a series of steps of hot rolling a steel slab having a chemical composition of C: 0.001 ⁇ 0.10 mass%, Si:1.0 ⁇ 5.0 mass%, Mn:0.01 ⁇ 0.5 mass%, sol.
- the method of producing a grain-oriented electrical steel sheet according to the invention is characterized in that a total N content in the steel slab NB'(massppm) is used instead of the N amount precipitated after the primary recrystallization annealing NB (massppm).
- the method of producing a grain-oriented electrical steel sheet according to the invention is characterized in that the steel slab contains one or more selected from Cu: 0.01 ⁇ 0.2 mass%, Ni: 0.01 ⁇ 0.5 mass%, Cr: 0.01 ⁇ 0.5 mass%, Mo: 0.01 ⁇ 0.5 mass%, Sb: 0.01 ⁇ 0.1 mass%, Sn: 0.01 ⁇ 0.5 mass%, Bi: 0.001 ⁇ 0.1 mass%, P: 0.001 ⁇ 0.05 mass%, Ti: 0.005 ⁇ 0.02 mass% and Nb: 0.0005 ⁇ 0.100 mass% in addition to the above chemical composition.
- the secondary recrystallized grains can be stably refined over the full length of the product coil, so that it is possible to produce a grain-oriented electrical steel sheet having low iron loss in a high yield.
- FIG. 1 is a view illustrating a comparison between heating pattern of the invention and heating pattern of the conventional technique in primary recrystallization annealing.
- the refining of the secondary recrystallized grains can be stably attained by setting a high heating rate with respect to a relatively low temperature zone mainly enhancing only the recovery (low temperature zone) and setting a heating rate lower than that of the low temperature zone with respect to a relatively high temperature zone enhancing both of the recovery and the recrystallization (high temperature zone).
- a nucleus of the Goss orientation ( ⁇ 110 ⁇ 001>) is located in a deformation band formed in ⁇ 111 ⁇ fiber structure easily storing strain energy of rolling structure.
- the deformation band is a region particularly storing strain energy in the ⁇ 111 ⁇ fiber structure.
- the heating rate of the low temperature zone in the primary recrystallization annealing is low, a deformation band having extremely high strain energy is preferentially recovered to release the strain energy, so that the recrystallization of the Goss orientation nucleus is hardly caused. While when the heating rate of the low temperature zone is high, the deformation band can be kept at a state of the high strain energy to a high temperature, so that the recrystallization of the Goss orientation nucleus can be preferentially caused.
- the ⁇ 111 ⁇ primary recrystallization texture is produced by the recrystallization of the ⁇ 111 ⁇ fiber structure in the rolling texture. Also, since the rolling texture is oriented in the ⁇ 111 ⁇ fiber structure, the main orientation of the primary recrystallization texture is the ⁇ 111 ⁇ primary recrystallization texture unless any special heat treatment is conducted. Also, the ⁇ 111 ⁇ fiber structure is high in the strain energy as compared to other surrounding textures though the energy is not so much as that of the deformation band generating nuclei of the Goss orientation. Therefore, it is said to be a crystal orientation easy to be recrystallized next to the Goss orientation under a heat treatment condition that the rapid-heating is conducted in the low temperature zone mainly enhancing only the recovery.
- the ranges of the low temperature zone and the high temperature zone have a close relation to the recovery temperature and recrystallization temperature of the material, so that they vary depending on the precipitation state of solute nitrogen having an effect of inhibiting polygonization of dislocation in the primary recrystallization annealing to delay the recovery of the structure and the start of the recrystallization, concretely by N amount precipitated in the primary recrystallization annealing. Therefore, it is necessary to change the heating rate depending on the above precipitated N amount.
- the invention is based on the technical idea described above.
- the C is an element useful for generating the Goss orientation grains and is necessary to be included in an amount of not less than 0.001 mass% in order to develop such an effect.
- the C amount exceeds 0.10 mass%, there is a risk of deteriorating the magnetic properties due to an insufficient decarburization in the decarburization annealing. Therefore, the C amount is in the range of 0.001 to 0.10 mass%. Preferably, it is in the range of 0.005 to 0.08 mass%.
- Si has an effect of increasing an electrical resistance of steel to reduce iron loss and is necessary to be added in an amount of at least 1.0 mass% in the invention.
- the Si amount is in the range of 1.0 to 5.0 mass%. Preferably, it is in the range of 2.0 to 4.5 mass%.
- Mn not only effectively contributes to the improvement of the hot brittleness of steel, but also forms precipitates of MnS, MnSe or the like to develop a function as an inhibitor when S and Se are included.
- the Mn content is less than 0.01 mass%, the above effect is not sufficient, while when the addition amount exceeds 0.5 mass%, the slab heating temperature required for dissolving the precipitates such as MnS, MnSe or the like becomes extremely high, which is not preferable. Therefore, the Mn content is in the range of 0.01 to 0.5 mass%. Preferably, it is in the range of 0.01 to 0.3 mass%.
- Al is a useful element forming AlN in steel and precipitating as a second dispersion phase to act as an inhibitor.
- the content as sol. Al is less than 0.003 mass%, the sufficient precipitation amount cannot be ensured and the above effect is not obtained.
- it exceeds 0.050 mass% as sol. Al the slab heating temperature necessary for solid solution of AlN becomes extremely high and also AlN is coarsened by the heat treatments after the hot rolling to lose the function as an inhibitor. Therefore, Al content is in the range of 0.003 to 0.050 mass% as sol. Al. Preferably, it is in the range of 0.005 to 0.040 mass%.
- N is an element required for forming AlN as an inhibitor like Al.
- the addition amount is less than 0.0010 mass%, the precipitation of AlN is insufficient, while when it exceeds 0.020 mass%, blistering or the like is caused in heating the slab. Therefore, N content is in the range of 0.0010 to 0.020 mass%. Preferably, it is in the range of 0.0030 to 0.015 mass%.
- S and Se are useful elements which are precipitated as a second dispersion phase in steel by bonding to Mn or Cu to form MnS, MnSe, Cu 2-x S or Cu 2-x Se to thereby act as an inhibitor.
- the addition amount of S and Se in total is less than 0.005 mass%, the above addition effect is not obtained sufficiently, while when it exceeds 0.040 mass%, not only solving S and Se to steel is insufficient in the heating of the slab, but also surface defects are caused in a product. Therefore, the addition amount of S and Se is in the range of 0.005 to 0.040 mass% without regard for the single addition and the composite addition. Preferably, it is in the range of 0.005 to 0.0030 mass%.
- the grain-oriented electrical steel sheet of the invention may contain at least one selected from Cu: 0.01 ⁇ 0.2 mass%, Ni: 0.01 ⁇ 0.5 mass%, Cr: 0.01 ⁇ 0.5 mass%, Mo: 0.01 ⁇ 0.5 mass%, Sb: 0.01 ⁇ 0.1 mass%, Sn: 0.01 ⁇ 0.5 mass%, Bi: 0.001 ⁇ 0.1 mass%, P: 0.001 ⁇ 0.05 mass%, Ti: 0.005 ⁇ 0.02 mass% and Nb: 0.0005 ⁇ 0.0100 mass%.
- Cu, Ni, Cr, Mo, Sb, Sn, Bi, P, Ti and Nb are elements easily segregating into crystal grain boundary or surface or elements forming carbonitride and have a subsidiary action as an inhibitor. Therefore, the addition of these elements can further improve the magnetic properties.
- the addition amount is less than the above lower limit, the effect of suppressing the coarsening of the primary recrystallized grains is not obtained sufficiently at a higher temperature zone of the secondary recrystallization process, while when it exceeds the above upper limit, there is a risk of causing poor secondary recrystallization or poor appearance of the coating. Therefore, if such elements are added, it is preferable to be added in the aforementioned range.
- the steel slab used as a raw material of the grain-oriented electrical steel sheet according to the invention is necessary to contain N in an amount of not less than 0.0010 mass% and a nitride-forming element such as Al or the like precipitating by forming nitride.
- the remainder other than the aforementioned components is Fe and inevitable impurities.
- other components may be contained within the scope not damaging the effect of the invention.
- the method of producing the grain-oriented electrical steel sheet according to the invention comprises a series of steps of hot-rolling a steel slab having the above chemical composition suitable for the invention, subjecting the hot rolled sheet to a hot band annealing if necessary, subjecting the sheet to a single cold rolling or two or more cold rollings with an intermediate annealing therebetween to obtain a cold rolled sheet having a final thickness, subjecting the cold rolled sheet to primary recrystallization annealing, applying an annealing separator composed mainly of MgO, Al 2 O 3 or the like, and subjecting the sheet to a final annealing.
- the method of producing the steel slab is not particularly limited except that it is necessary to adjust the chemical composition so as to conform with the invention, and well-known production methods can be used. Also, the reheating temperature of the steel slab prior to the hot rolling is preferable to be not lower than 1300°C because it is necessary to solve the inhibitor-forming elements completely.
- the conditions of the hot rolling, the conditions of the hot band annealing conducted if necessary, and the conditions of the single cold rolling or two or more cold rollings with an intermediate annealing therebetween for the formation of a cold rolled sheet having a final thickness are not particularly limited as long as they are conducted according to the usual manner. Moreover, aging between rolling passes or warm rolling may be properly adopted in the cold rolling. The production conditions after the cold rolling will be explained below.
- the effect of stably reducing the iron loss can be obtained by setting the heating rate in the low temperature zone to not less than 80°C/sec which is higher than of the usual primary recrystallization annealing and setting the heating rate in the high temperature zone to the range of 0.1 to 0.7 times of the heating rate of the low temperature zone.
- the temperature ranges of the low temperature zone and high temperature zone during the heating process are determined based on the precipitation state of N in the steel sheet.
- the solute nitrogen existing after the cold rolling is unevenly distributed on the crystal grain boundary or dislocation and forms nitrides to be finely precipitated on the dislocation during the heating process of the primary recrystallization annealing so that it has an effect of limiting the movement of the dislocation to inhibit the polygonization, or an effect of recovering the rolled structure or delaying the recrystallization. Therefore, it is considered that the amount of N precipitated in the primary recrystallization annealing largely affects the recovery or the recrystallization.
- the inventors have measured N amount NA (massppm) precipitated in the steel sheet after the final cold rolling and N amount NB (massppm) precipitated in the steel sheet after the primary recrystallization annealing and presumed the difference (NB-NA) (massppm) to be N amount newly precipitated by the primary recrystallization annealing and made many experiments for studying a relation between the difference (NB-NA) and heating conditions for obtaining good magnetic properties (heating rate, temperature range). As a result, we have found that proper heating conditions exist depending on (NB-NA) as mentioned later.
- a heating rate S1 between a temperature T1 determined from the following equation (1) and a temperature T2 determined from the following equation (2) is necessary to be not less than 80°C/sec.
- the heating rate S1 in this temperature range is slower than 80°C/sec, the recovery is caused in the deformation band producing the nucleus of the Goss orientation ⁇ 110 ⁇ ⁇ 001>, and preferential recrystallization in the nucleus of the Goss orientation is not caused and the number of the nuclei of the Goss orientation cannot be increased, so that secondary recrystallized grains cannot be refined.
- the heating rate in the low temperature zone is sufficient to be not less than 80°C/sec, so that an average heating rate from a temperature lower than T1 may be not less than 80°C/sec.
- the lowest temperature of the temperature range in the high temperature zone is the highest temperature T2 in the low temperature zone and corresponds to the temperature starting recrystallization of only a specific crystal orientation (Goss orientation) when heated at the heating rate S1.
- the highest temperature is a temperature of 750°C recrystallizing almost all crystals.
- the reason why the heating rate S2 is related to S1 is considered due to the fact that as the heating rate in the low temperature zone becomes higher, the recovery of the Goss orientation being preferentially recrystallized can be at an inhibited state, and even if a retention time in the high temperature zone is made short, the recrystallization of the Goss orientation can be promoted and an optimum heating rate in the high temperature zone becomes high in accordance with the heating rate S 1 in the low temperature zone.
- the heating rate S2 in the high temperature zone is too high, the recrystallization of texture intended to preferentially recrystallize is also at an inhibited state, and all of orientations is recrystallized to randomize recrystallization texture to thereby cause poor secondary recrystallization. Therefore, it is preferable to limit the heating rate S2 to not more than 0.7 times of S1. Inversely, when the heating rate S2 is too slow, ⁇ 111 ⁇ primary recrystallized texture is increased and the effect of refining secondary grains is not obtained, so that it is preferable to be not less than 0.1 times of S 1.
- the preferable S2 is in the range of 0.2 to 0.6 times of S1.
- the primary recrystallization annealing is ordinarily conducted in combination with decarburization annealing. Even in the invention, the primary recrystallization annealing combined with decarburization annealing may be conducted. In this case, it is preferable that the decarburization annealing is conducted by heating at a heating rate suitable for the invention under such a wet hydrogen atmosphere that an oxidation potential PH 2 O/PH 2 of the atmosphere is not less than 0.1. Furthermore, when there is restriction on the annealing facility, the decarburization annealing may be performed after the heating treatment at the temperature range and heating rate suitable for the invention is conducted in a non-oxidizing atmosphere.
- the steel sheet subjected to the primary recrystallization annealing as described above is subsequently coated on the steel sheet surface with an annealing separator and then subjected to a final annealing of generating secondary recrystallization.
- the annealing separator can be used, for example, ones composed mainly of MgO and added with TiO 2 if necessary, in case of forming forsterite coating or ones composed mainly of SiO 2 or Al 2 O 3 in case of forming no forsterite coating.
- a product sheet is obtained by applying and baking an insulation coating on the surface of the steel sheet or subjecting to flattening annealing for correcting the shape if necessary.
- the kind of the insulation coating is not particularly limited, but it is preferable to use a tension coating for providing tensile force to the surface of the steel sheet in order to further reduce the iron loss.
- the insulation coating may be formed by again applying an aqueous slurry composed mainly of MgO onto the surface of the steel sheet after the final annealing and subjecting to an annealing for forming a forsterite coating.
- the steel sheet after the final annealing may be subjected to a well-known magnetic domain subdividing treatment by lineally conducting plasma jet or laser irradiation or electron beam irradiation or by providing linear strain with a protruded roll.
- the secondary recrystallization texture can be stably refined over the full length of the product coil, so that grain-oriented electrical steel sheets having low iron loss can be produced in a high yield.
- a steel slab containing C: 0.06 mass%, Si: 3.3 mass%, Mn: 0.08 mass%, S: 0.023 mass%, sol. Al: 0.03 mass%, N: 0.008 mass%, Cu: 0.2 mass% and Sb: 0.02 mass% is heated to 1430 °C and soaked for 30 minutes and hot rolled to obtain a hot rolled sheet having a sheet thickness of 2.2 mm, which is subjected to a hot band annealing at 1000°C for 1 minute, cold rolled to obtain an intermediate cold rolled sheet having a sheet thickness of 1.5 mm and subjected to an intermediate annealing.
- the intermediate annealing is conducted under two conditions that the sheet is heated to 1100°C and cooled at a rate of 30°C/sec to promote the precipitation of N and that the sheet is heated to 1150°C and cooled at a rate of 100°C/sec to keep N at a solid solution state. Thereafter, the sheet is further cold rolled to obtain a cold rolled sheet having a final thickness of 0.23 mm.
- a test specimen of 100mm x 300mm is taken out from a central portion in longitudinal and widthwise directions of each of the cold rolled sheet coils thus obtained and subjected to a primary recrystallization annealing combined with a primary recrystallization and decarburization in a laboratory.
- the primary recrystallization annealing is conducted with an electrical heating furnace by heating while varying heating rates from 300°C and 800°C as shown in Table 1 and then promoting decarburization while keeping at 840°C for 2 minutes.
- PH 2 O/PH 2 of the atmosphere is controlled to 0.3.
- test specimen taken out from the cold rolled sheet is electrolyzed, filtered and extracted with an AA-based electrolytic solution (acetylacetone) of 10 mass%, and then N amount precipitated in the cold rolled sheet is quantified from the remaining residue to determine N amount precipitated in the cold rolled sheet NA.
- N amount precipitated in the steel sheet after the primary recrystallization annealing is measured in the same way to determine N amount precipitated after the primary recrystallization annealing NB.
- the difference between NA and NB (NB-NA) is determined as N amount newly precipitated by the primary recrystallization annealing.
- test specimens subjected to the primary recrystallization annealing are prepared with respect to each of the respective heating conditions.
- an annealing separator composed mainly of MgO and added with 10 mass% of TiO 2 is applied onto each surface of these test specimens in form of an aqueous slurry and dried, the test specimen is subjected to a final annealing to conduct secondary recrystallization and then coated and baked with a phosphate-based insulation tension coating.
- iron loss W 17/50 is measured with a single sheet tester to determine an average value and a standard deviation.
- the coating is removed from the test specimen by pickling, and then a secondary recrystallized grain size in a length range of 300 mm is measured by a linear analysis to determine an average value on the 50 test specimens.
- Table.1 As seen from these results, the steel sheets subjected to the heating in the primary recrystallization annealing under conditions according to the invention are small in the secondary recrystallized grain size and good in the iron loss properties and show reduced dispersion.
- a steel slab having a chemical composition shown in Table 2 and Table 3 is heated at 1400°C for 20 minutes, hot rolled to obtain a hot rolled sheet of 2.0 mm in thickness, subjected to a hot band annealing at 1000°C for 1 minute, cold rolled to obtain an intermediate cold rolled sheet of 1.5 mm in thickness, subjected to an intermediate annealing at 1100°C for 2 minutes, cold rolled to obtain a final cold rolled sheet having a thickness of 0.23 mm, and then subjected to a magnetic domain subdividing treatment by forming linear grooves through electrolytic etching.
- an aqueous slurry of an annealing separator composed mainly of MgO and added with 10 mass% of TiO 2 is applied and dried on the surface of the steel sheet after the primary recrystallization, and the sheet is wound in a coil, subjected to a final annealing, and subjected to a flattening annealing for the purpose of applying and baking a phosphate-based insulation tension coating and flattening the steel sheet to thereby produce a product sheet.
- N amount precipitated in the steel sheet after the cold rolling NA and N amount precipitated in the steel sheet after the primary recrystallization NB are determined by analyzing the test specimens cut out from longitudinal end portions and widthwise central portion of the coil.
- the sheets of Invention Examples heated under the conditions according to the invention are good in the worst value of iron loss W 17/50 and high in the ratio of the portion having iron loss W 17/50 of not more than 0.80 w/kg (achievement ratio).
- Table 3 No. Chemical composition (mass%) N amount precipitated (massppm) Heating rate(°C/s) Iron loss W 17/50 Remarks C Si Mn S Se sol.
- N in steel is not actively increased (not nitrided) in the primary recrystallization as in this example, it may be considered that all of the N amount in the steel slab is precipitated after the primary recrystallization annealing. In the actual operation, therefore, if the N amount precipitated after the cold rolling (before the primary recrystallization annealing) becomes clear, it is possible to set appropriate heating rate patterns. Also, if the production condition such as annealing pattern before the final cold rolling or the like is constant, it is possible to estimate N amount precipitated in the steel sheet after the cold rolling based on preliminary research.
- the technique of the invention is applicable to improve textures of non-oriented electrical steel sheets or to improve textures of thin steel sheets.
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Description
- This invention relates to a method of producing a grain-oriented electrical steel sheet, and more particularly to a method of producing a grain-oriented electrical steel sheet being excellent in the iron loss properties throughout the whole length of a product coil.
- The grain-oriented electrical steel sheet is a soft magnetic material where its crystal orientation is highly oriented in the Goss orientation ({110} <001>) and is mainly used as cores for transformers or the like. The grain-oriented electrical steel sheet used in the transformer is required to have low iron loss W17/50 (W/kg) representing magnetic loss when being magnetized to 1.7 T at a frequency of 50 Hz in order to reduce no-load loss (energy loss).
- The iron loss of the electrical steel sheet is represented as the sum of hysteresis loss depending on crystal orientation, purity and the like and eddy-current loss depending on specific resistance, sheet thickness, magnetic domain size and the like. Therefore, as a method for reducing the iron loss are known a method of enhancing an accumulation degree of crystal orientation to improve a magnetic flux density, a method of increasing Si content for enhancing an electric resistance, a method of reducing a thickness of a steel sheet, a method of refining secondary recrystallized grains, a method of refining magnetic domain and so on.
- Among them, as a technique for refining the secondary recrystallized grains is known a method of rapidly heating during the decarburization annealing or a method of conducting a rapidly heating treatment just before the decarburization annealing to improve primary recrystallized texture. For example, Patent Document 1 discloses that the grain-oriented electrical steel sheet having extremely low iron loss can be obtained by heating the steel sheet rolled to a final thickness to a temperature of not lower than 700°C at a heating rate of not less than 100°C/sec in a non-oxidizing atmosphere having PH2O/PH2 of not more than 0.2 just before decarburization annealing, and also Patent Document 2 discloses that the grain-oriented electrical steel sheet having extremely low iron loss can be obtained by rapidly heating the steel sheet rolled to a final thickness to 800∼950°C at a heating rate of not less than 100°C/sec in an atmosphere having an oxygen concentration of not more than 500 ppm before the decarburization annealing, and conducting decarburization annealing wherein a temperature of a preceding zone at the decarburization annealing step is 775∼840°C lower than a temperature achieved by the rapid-heating and a temperature of subsequent latter zone is 815-875 °C higher than the temperature of the preceding zone. Further, Patent Documents 3 and 4 disclose that grain-oriented electrical steel sheets being excellent in the film properties and magnetic properties can be obtained by heating a temperature zone of at least not less than 600°C at a heating stage of decarburization annealing step to not lower than 800°C at a heating rate of not less than 95°C/s or not less than 100°C/s and properly controlling an atmosphere of this temperature zone. Patent Document 5 relates to a method for stably achieving a good iron loss reducing effect by rapid heating treatment of a steel sheet in a case where primary recrystallization annealing including rapid heating treatment is carried out in a method for manufacturing a grain oriented electrical steel sheet using an inhibitor-free material.
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- Patent Document 1:
JP-A-H07-062436 - Patent Document 2:
JP-A-H10-298653 - Patent Document 3:
JP-A-2003-027194 - Patent Document 4:
JP-A-2000-204450 - Patent Document 5:
WO 2011/105054 A1 - Most of the conventional techniques are intended to improve the primary recrystallization texture and refine secondary recrystallized grains by unambiguously determining the starting temperature of the rapid-heating and defining the achieving temperature of the rapid-heating as not lower than 700°C. According to the inventors' studies, it becomes clear that the secondary recrystallized grains can be surely refined to improve the iron loss by applying the above conventional techniques in most cases, but there is a case that secondary recrystallization behavior is not stabilized and the above improvement effect cannot be obtained over a full length of a coil depending on the precipitation states before the rapid-heating.
- The invention is made in view of the above problems inherent to the conventional techniques and is to propose a method of producing a grain-oriented electrical steel sheet which is capable of stabilizing secondary recrystallization behavior to refine secondary recrystallized grains over a full length of a product coil to thereby make the iron loss of the full length of the product coil lower.
- In order to solve the above problems, the inventors have made various studies from various viewpoints over an influence of precipitation state of nitrogen (N) in steel sheet in the raid-heating temperature zone, fixed in the conventional techniques, on primary recrystallization behavior. As a result, it has been found that a preferable rapid-heating temperature zone may vary depending on the precipitation state (precipitation amount) of N in the steel sheet. In general, solute nitrogen in the steel sheet is unevenly distributed on a crystal grain boundary or a dislocation, while solute nitrogen retained in the steel sheet after the cold rolling precipitates in the heating process of subsequent heat treatment, but most of them precipitate on the dislocation to inhibit polygonization of the dislocation, which has effects of delaying recovery of microstructure and start of recrystallization. Such effects are considered to vary depending on the precipitation state.
- Now, the inventors have made further studies in consideration that the refining of secondary recrystallized grains can be stably attained by accurately understanding and controlling a relation between recovery temperature zone or recrystallization temperature zone and heating rate. Consequently, it has been found out that the refining of secondary recrystallized grains can be stably attained by setting an optimum heating rate with respect to each of the recovery temperature zone and the recrystallization temperature zone, i.e., as shown in
FIG. 1 , by setting a high heating rate with respect to a relatively low temperature zone mainly enhancing only the recovery (hereinafter referred to as "low temperature zone") and setting a heating rate lower than that of the above low temperature zone with respect to a relatively high temperature zone enhancing both of the recovery and the recrystallization (hereinafter referred to as "high temperature zone") and as a result, the invention has been accomplished. - That is, the invention is a method of producing a grain-oriented electrical steel sheet which comprises a series of steps of hot rolling a steel slab having a chemical composition of C: 0.001~0.10 mass%, Si:1.0∼5.0 mass%, Mn:0.01∼0.5 mass%, sol. Al: 0.003~0.050 mass%, N: 0.0010∼0.020 mass%, one or two selected from S and Se: 0.005~0.040 mass% in total, and the remainder being Fe and inevitable impurities, subjecting the resulting sheet to a hot band annealing if necessary, conducting a single cold rolling or two or more cold rollings with an intermediate annealing therebetween to form a cold rolled sheet having a final thickness, conducting a primary recrystallization annealing, applying an annealing separator and conducting a final annealing, characterized in that in a heating process of the primary recrystallization annealing, a heating rate S1 from a temperature T1 to a temperature T2, which are determined by the following equations (1) and (2):
- The method of producing a grain-oriented electrical steel sheet according to the invention is characterized in that a total N content in the steel slab NB'(massppm) is used instead of the N amount precipitated after the primary recrystallization annealing NB (massppm).
- Also, the method of producing a grain-oriented electrical steel sheet according to the invention is characterized in that the steel slab contains one or more selected from Cu: 0.01~0.2 mass%, Ni: 0.01~0.5 mass%, Cr: 0.01∼0.5 mass%, Mo: 0.01∼0.5 mass%, Sb: 0.01~0.1 mass%, Sn: 0.01∼0.5 mass%, Bi: 0.001~0.1 mass%, P: 0.001∼0.05 mass%, Ti: 0.005~0.02 mass% and Nb: 0.0005∼0.100 mass% in addition to the above chemical composition.
- According to the invention, the secondary recrystallized grains can be stably refined over the full length of the product coil, so that it is possible to produce a grain-oriented electrical steel sheet having low iron loss in a high yield.
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FIG. 1 is a view illustrating a comparison between heating pattern of the invention and heating pattern of the conventional technique in primary recrystallization annealing. - First, there will be explained the basic technical concept of the invention that the refining of the secondary recrystallized grains can be stably attained by setting a high heating rate with respect to a relatively low temperature zone mainly enhancing only the recovery (low temperature zone) and setting a heating rate lower than that of the low temperature zone with respect to a relatively high temperature zone enhancing both of the recovery and the recrystallization (high temperature zone).
- It is necessary to control primary recrystallization texture in order to improve secondary recrystallization behavior. In particular, in order to refine the secondary recrystallized grains, the number of nuclei of Goss orientation ({110}<001>) is important. Also, in order to stably induce the secondary recrystallization and to prevent secondary recrystallized grains from coarsening, the amount of {111} primary recrystallization texture encroached by the Goss orientation is greatly concerned.
- First, the reason why the heating rate in the low temperature zone mainly enhancing only the recovery is increased will be explained below.
- It is known that a nucleus of the Goss orientation ({110}<001>) is located in a deformation band formed in {111} fiber structure easily storing strain energy of rolling structure. The deformation band is a region particularly storing strain energy in the {111} fiber structure.
- When the heating rate of the low temperature zone in the primary recrystallization annealing is low, a deformation band having extremely high strain energy is preferentially recovered to release the strain energy, so that the recrystallization of the Goss orientation nucleus is hardly caused. While when the heating rate of the low temperature zone is high, the deformation band can be kept at a state of the high strain energy to a high temperature, so that the recrystallization of the Goss orientation nucleus can be preferentially caused.
- Next, the reason why the heating rate in the high temperature zone subsequent to the above low temperature zone is made lower than that of the low temperature zone and the heating rate is limited to a specific range will be explained below.
- In general, when the amount of {111} primary recrystallization texture easily encroached by the Goss orientation ({110} <001>) is too large, the growth of the secondary recrystallized grains (Goss orientation grains) is promoted, so that there is a fear that even if there are many nuclei of the Goss orientation, one crystal grain is coarsened before the growth of these nuclei. On the other hand, when the amount of the {111} primary recrystallization texture is too small, the growth of the secondary recrystallized grains is difficult and the failure of secondary recrystallization is caused. Therefore, it is necessary to control the {111} primary recrystallization texture to a proper amount.
- Here, the {111} primary recrystallization texture is produced by the recrystallization of the {111} fiber structure in the rolling texture. Also, since the rolling texture is oriented in the {111} fiber structure, the main orientation of the primary recrystallization texture is the {111} primary recrystallization texture unless any special heat treatment is conducted. Also, the {111} fiber structure is high in the strain energy as compared to other surrounding textures though the energy is not so much as that of the deformation band generating nuclei of the Goss orientation. Therefore, it is said to be a crystal orientation easy to be recrystallized next to the Goss orientation under a heat treatment condition that the rapid-heating is conducted in the low temperature zone mainly enhancing only the recovery.
- It is possible to promote the recrystallization from the deformation band keeping the strain energy or the {111} fiber structure by making slow the heating rate in the high temperature zone after the rapid-heating in the low temperature zone. However, when the heating rate is made too slow, the number of the nuclei of the Goss orientation is somewhat increased, while the {111} primary recrystallization structure originally being a main orientation of the structure is further increased in excess. As a result, the {111} primary recrystallization structure becomes too much and the Goss orientation grains are coarsened in the secondary recrystallization annealing.
- However, when the heating in the relatively high temperature zone simultaneously enhancing the recovery and the recrystallization is conducted at the same heating rate as in the low temperature zone, crystals in all orientations start the primary recrystallization before the recrystallization in the Goss orientation or the {111} primary recrystallization structure and hence the texture is randomized. As a result, the {111} primary recrystallization structure becomes decreased and the secondary recrystallization itself may not be generated.
- Here, the ranges of the low temperature zone and the high temperature zone have a close relation to the recovery temperature and recrystallization temperature of the material, so that they vary depending on the precipitation state of solute nitrogen having an effect of inhibiting polygonization of dislocation in the primary recrystallization annealing to delay the recovery of the structure and the start of the recrystallization, concretely by N amount precipitated in the primary recrystallization annealing. Therefore, it is necessary to change the heating rate depending on the above precipitated N amount.
- The invention is based on the technical idea described above.
- Next, the chemical composition of the steel slab used as a raw material for the grain-oriented electrical steel sheet of the invention will be explained below.
- C is an element useful for generating the Goss orientation grains and is necessary to be included in an amount of not less than 0.001 mass% in order to develop such an effect. On the other hand, when the C amount exceeds 0.10 mass%, there is a risk of deteriorating the magnetic properties due to an insufficient decarburization in the decarburization annealing. Therefore, the C amount is in the range of 0.001 to 0.10 mass%. Preferably, it is in the range of 0.005 to 0.08 mass%.
- Si has an effect of increasing an electrical resistance of steel to reduce iron loss and is necessary to be added in an amount of at least 1.0 mass% in the invention. On the other hand, when it is added in an amount exceeding 5.0 mass%, it is difficult to conduct the cold rolling. Therefore, the Si amount is in the range of 1.0 to 5.0 mass%. Preferably, it is in the range of 2.0 to 4.5 mass%.
- Mn not only effectively contributes to the improvement of the hot brittleness of steel, but also forms precipitates of MnS, MnSe or the like to develop a function as an inhibitor when S and Se are included. When the Mn content is less than 0.01 mass%, the above effect is not sufficient, while when the addition amount exceeds 0.5 mass%, the slab heating temperature required for dissolving the precipitates such as MnS, MnSe or the like becomes extremely high, which is not preferable. Therefore, the Mn content is in the range of 0.01 to 0.5 mass%. Preferably, it is in the range of 0.01 to 0.3 mass%.
- Al is a useful element forming AlN in steel and precipitating as a second dispersion phase to act as an inhibitor. However, when the content as sol. Al is less than 0.003 mass%, the sufficient precipitation amount cannot be ensured and the above effect is not obtained. While when it exceeds 0.050 mass% as sol. Al, the slab heating temperature necessary for solid solution of AlN becomes extremely high and also AlN is coarsened by the heat treatments after the hot rolling to lose the function as an inhibitor. Therefore, Al content is in the range of 0.003 to 0.050 mass% as sol. Al. Preferably, it is in the range of 0.005 to 0.040 mass%.
- N is an element required for forming AlN as an inhibitor like Al. However, when the addition amount is less than 0.0010 mass%, the precipitation of AlN is insufficient, while when it exceeds 0.020 mass%, blistering or the like is caused in heating the slab. Therefore, N content is in the range of 0.0010 to 0.020 mass%. Preferably, it is in the range of 0.0030 to 0.015 mass%.
- S and Se are useful elements which are precipitated as a second dispersion phase in steel by bonding to Mn or Cu to form MnS, MnSe, Cu2-xS or Cu2-xSe to thereby act as an inhibitor. When the addition amount of S and Se in total is less than 0.005 mass%, the above addition effect is not obtained sufficiently, while when it exceeds 0.040 mass%, not only solving S and Se to steel is insufficient in the heating of the slab, but also surface defects are caused in a product. Therefore, the addition amount of S and Se is in the range of 0.005 to 0.040 mass% without regard for the single addition and the composite addition. Preferably, it is in the range of 0.005 to 0.0030 mass%.
- In addition to the above chemical composition, the grain-oriented electrical steel sheet of the invention may contain at least one selected from Cu: 0.01~0.2 mass%, Ni: 0.01~0.5 mass%, Cr: 0.01~0.5 mass%, Mo: 0.01∼0.5 mass%, Sb: 0.01∼0.1 mass%, Sn: 0.01∼0.5 mass%, Bi: 0.001∼0.1 mass%, P: 0.001~0.05 mass%, Ti: 0.005∼0.02 mass% and Nb: 0.0005∼0.0100 mass%.
- Cu, Ni, Cr, Mo, Sb, Sn, Bi, P, Ti and Nb are elements easily segregating into crystal grain boundary or surface or elements forming carbonitride and have a subsidiary action as an inhibitor. Therefore, the addition of these elements can further improve the magnetic properties. However, when the addition amount is less than the above lower limit, the effect of suppressing the coarsening of the primary recrystallized grains is not obtained sufficiently at a higher temperature zone of the secondary recrystallization process, while when it exceeds the above upper limit, there is a risk of causing poor secondary recrystallization or poor appearance of the coating. Therefore, if such elements are added, it is preferable to be added in the aforementioned range.
- As described above, the steel slab used as a raw material of the grain-oriented electrical steel sheet according to the invention is necessary to contain N in an amount of not less than 0.0010 mass% and a nitride-forming element such as Al or the like precipitating by forming nitride.
- Moreover, the remainder other than the aforementioned components is Fe and inevitable impurities. However, other components may be contained within the scope not damaging the effect of the invention.
- The method of producing the grain-oriented electrical steel sheet according to the invention will be explained below.
- The method of producing the grain-oriented electrical steel sheet according to the invention comprises a series of steps of hot-rolling a steel slab having the above chemical composition suitable for the invention, subjecting the hot rolled sheet to a hot band annealing if necessary, subjecting the sheet to a single cold rolling or two or more cold rollings with an intermediate annealing therebetween to obtain a cold rolled sheet having a final thickness, subjecting the cold rolled sheet to primary recrystallization annealing, applying an annealing separator composed mainly of MgO, Al2O3 or the like, and subjecting the sheet to a final annealing.
- The method of producing the steel slab is not particularly limited except that it is necessary to adjust the chemical composition so as to conform with the invention, and well-known production methods can be used. Also, the reheating temperature of the steel slab prior to the hot rolling is preferable to be not lower than 1300°C because it is necessary to solve the inhibitor-forming elements completely.
- Further, the conditions of the hot rolling, the conditions of the hot band annealing conducted if necessary, and the conditions of the single cold rolling or two or more cold rollings with an intermediate annealing therebetween for the formation of a cold rolled sheet having a final thickness are not particularly limited as long as they are conducted according to the usual manner. Moreover, aging between rolling passes or warm rolling may be properly adopted in the cold rolling. The production conditions after the cold rolling will be explained below.
- In the primary recrystallization annealing after the cold rolling, it is necessary to properly control the heating rates in the low temperature zone mainly enhancing only the recovery and the high temperature zone enhancing primary recrystallization in addition to the recovery during the heating process in order to stably refine the secondary recrystallized grains and enhance a ratio of low iron loss zone in the coil. Concretely, the effect of stably reducing the iron loss can be obtained by setting the heating rate in the low temperature zone to not less than 80°C/sec which is higher than of the usual primary recrystallization annealing and setting the heating rate in the high temperature zone to the range of 0.1 to 0.7 times of the heating rate of the low temperature zone.
- Here, the temperature ranges of the low temperature zone and high temperature zone during the heating process are determined based on the precipitation state of N in the steel sheet. The solute nitrogen existing after the cold rolling is unevenly distributed on the crystal grain boundary or dislocation and forms nitrides to be finely precipitated on the dislocation during the heating process of the primary recrystallization annealing so that it has an effect of limiting the movement of the dislocation to inhibit the polygonization, or an effect of recovering the rolled structure or delaying the recrystallization. Therefore, it is considered that the amount of N precipitated in the primary recrystallization annealing largely affects the recovery or the recrystallization.
- Under such an idea, the inventors have measured N amount NA (massppm) precipitated in the steel sheet after the final cold rolling and N amount NB (massppm) precipitated in the steel sheet after the primary recrystallization annealing and presumed the difference (NB-NA) (massppm) to be N amount newly precipitated by the primary recrystallization annealing and made many experiments for studying a relation between the difference (NB-NA) and heating conditions for obtaining good magnetic properties (heating rate, temperature range). As a result, we have found that proper heating conditions exist depending on (NB-NA) as mentioned later.
-
- The above equations (1) and (2) show that as the N amount precipitated in the primary recrystallization annealing is increased, the recovery and recrystallization are delayed and the temperature range in the low temperature zone is made higher.
- Also, when the heating rate S1 in this temperature range is slower than 80°C/sec, the recovery is caused in the deformation band producing the nucleus of the Goss orientation {110} <001>, and preferential recrystallization in the nucleus of the Goss orientation is not caused and the number of the nuclei of the Goss orientation cannot be increased, so that secondary recrystallized grains cannot be refined.
- In the invention, the heating rate in the low temperature zone is sufficient to be not less than 80°C/sec, so that an average heating rate from a temperature lower than T1 may be not less than 80°C/sec.
- It is preferable that the high temperature zone enhancing both the recovery and recrystallization is within a temperature range of the above T2 (=600 + 2(NB-NA)) to 750°C and the heating rate S2 thereof is in the range of 0.1 to 0.7 times of the heating rate S 1 in the low temperature zone.
- Here, the lowest temperature of the temperature range in the high temperature zone is the highest temperature T2 in the low temperature zone and corresponds to the temperature starting recrystallization of only a specific crystal orientation (Goss orientation) when heated at the heating rate S1. On the other hand, the highest temperature is a temperature of 750°C recrystallizing almost all crystals.
- Further, the reason why the heating rate S2 is related to S1 is considered due to the fact that as the heating rate in the low temperature zone becomes higher, the recovery of the Goss orientation being preferentially recrystallized can be at an inhibited state, and even if a retention time in the high temperature zone is made short, the recrystallization of the Goss orientation can be promoted and an optimum heating rate in the high temperature zone becomes high in accordance with the heating rate S 1 in the low temperature zone.
- However, when the heating rate S2 in the high temperature zone is too high, the recrystallization of texture intended to preferentially recrystallize is also at an inhibited state, and all of orientations is recrystallized to randomize recrystallization texture to thereby cause poor secondary recrystallization. Therefore, it is preferable to limit the heating rate S2 to not more than 0.7 times of S1. Inversely, when the heating rate S2 is too slow, {111} primary recrystallized texture is increased and the effect of refining secondary grains is not obtained, so that it is preferable to be not less than 0.1 times of S 1. The preferable S2 is in the range of 0.2 to 0.6 times of S1.
- In the invention, it is assumed that N unevenly distributed on the dislocation introduced by the cold rolling is precipitated by forming nitrides on the dislocation in the primary recrystallization annealing. Therefore, the invention cannot be applied when nitriding for increasing N amount in steel is carried out in the primary recrystallization annealing.
- In general, the primary recrystallization annealing is ordinarily conducted in combination with decarburization annealing. Even in the invention, the primary recrystallization annealing combined with decarburization annealing may be conducted. In this case, it is preferable that the decarburization annealing is conducted by heating at a heating rate suitable for the invention under such a wet hydrogen atmosphere that an oxidation potential PH2O/PH2 of the atmosphere is not less than 0.1. Furthermore, when there is restriction on the annealing facility, the decarburization annealing may be performed after the heating treatment at the temperature range and heating rate suitable for the invention is conducted in a non-oxidizing atmosphere.
- The steel sheet subjected to the primary recrystallization annealing as described above is subsequently coated on the steel sheet surface with an annealing separator and then subjected to a final annealing of generating secondary recrystallization. As the annealing separator can be used, for example, ones composed mainly of MgO and added with TiO2 if necessary, in case of forming forsterite coating or ones composed mainly of SiO2 or Al2O3 in case of forming no forsterite coating.
- After the unreacted annealing separator is removed from the surface of the finish annealed steel sheet, a product sheet is obtained by applying and baking an insulation coating on the surface of the steel sheet or subjecting to flattening annealing for correcting the shape if necessary. Moreover, the kind of the insulation coating is not particularly limited, but it is preferable to use a tension coating for providing tensile force to the surface of the steel sheet in order to further reduce the iron loss. For example, there can be preferably used an insulation coating formed by baking a coating liquid containing phosphate, chromic acid and colloidal silica as described in
JP-A-S50-79442 JP-A-S48-39338 - According to the production method of the invention, the secondary recrystallization texture can be stably refined over the full length of the product coil, so that grain-oriented electrical steel sheets having low iron loss can be produced in a high yield.
- A steel slab containing C: 0.06 mass%, Si: 3.3 mass%, Mn: 0.08 mass%, S: 0.023 mass%, sol. Al: 0.03 mass%, N: 0.008 mass%, Cu: 0.2 mass% and Sb: 0.02 mass% is heated to 1430 °C and soaked for 30 minutes and hot rolled to obtain a hot rolled sheet having a sheet thickness of 2.2 mm, which is subjected to a hot band annealing at 1000°C for 1 minute, cold rolled to obtain an intermediate cold rolled sheet having a sheet thickness of 1.5 mm and subjected to an intermediate annealing. The intermediate annealing is conducted under two conditions that the sheet is heated to 1100°C and cooled at a rate of 30°C/sec to promote the precipitation of N and that the sheet is heated to 1150°C and cooled at a rate of 100°C/sec to keep N at a solid solution state. Thereafter, the sheet is further cold rolled to obtain a cold rolled sheet having a final thickness of 0.23 mm.
- A test specimen of 100mm x 300mm is taken out from a central portion in longitudinal and widthwise directions of each of the cold rolled sheet coils thus obtained and subjected to a primary recrystallization annealing combined with a primary recrystallization and decarburization in a laboratory. Moreover, the primary recrystallization annealing is conducted with an electrical heating furnace by heating while varying heating rates from 300°C and 800°C as shown in Table 1 and then promoting decarburization while keeping at 840°C for 2 minutes. In this case, PH2O/PH2 of the atmosphere is controlled to 0.3.
- Also, the test specimen taken out from the cold rolled sheet is electrolyzed, filtered and extracted with an AA-based electrolytic solution (acetylacetone) of 10 mass%, and then N amount precipitated in the cold rolled sheet is quantified from the remaining residue to determine N amount precipitated in the cold rolled sheet NA. Also, N amount precipitated in the steel sheet after the primary recrystallization annealing is measured in the same way to determine N amount precipitated after the primary recrystallization annealing NB. The difference between NA and NB (NB-NA) is determined as N amount newly precipitated by the primary recrystallization annealing.
- Next, 50 test specimens subjected to the primary recrystallization annealing (decarburization annealing) are prepared with respect to each of the respective heating conditions. After an annealing separator composed mainly of MgO and added with 10 mass% of TiO2 is applied onto each surface of these test specimens in form of an aqueous slurry and dried, the test specimen is subjected to a final annealing to conduct secondary recrystallization and then coated and baked with a phosphate-based insulation tension coating.
- With respect to all of the 50 test specimens thus obtained for each heating condition, iron loss W17/50 is measured with a single sheet tester to determine an average value and a standard deviation. After the measurement of the iron loss, the coating is removed from the test specimen by pickling, and then a secondary recrystallized grain size in a length range of 300 mm is measured by a linear analysis to determine an average value on the 50 test specimens. The results are also shown in Table.1. As seen from these results, the steel sheets subjected to the heating in the primary recrystallization annealing under conditions according to the invention are small in the secondary recrystallized grain size and good in the iron loss properties and show reduced dispersion.
Table 1 Nº N amount precipitated (massppm) Heating rate and temperature range of controlling heating rate Average heating rate (°C / s) Iron loss W17/50 (W/kg) Secondary grain size (mm) Remarks NA NB Starting temperature (°C) Heating rate 1 (°C/s) Switching temperature (°C) Heating rate 2 (°C/s ) End temperature (°C) S1 S2 S1×0.1 S1×0.7 Average value Standard deviation 1 53 74 300 80 520 50 800 50 50 5 35 0.851 0.025 16.8 Comparative Example 2 54 73 300 80 550 50 800 50 50 5 35 0.853 0.022 17.5 Comparative Example 3 52 71 300 80 600 50 800 69 50 7 48 0.832 0.018 16.1 Comparative Example 4 53 75 300 80 650 50 800 80 51 8 56 0.802 0.019 11.2 Invention Example 5 50 73 300 80 700 50 800 80 62 8 56 0.820 0.028 10.0 Comparative Example 6 55 72 300 80 800 - 800 80 80 8 56 0.825 0.042 9.7 Comparative Example 7 54 75 300 100 600 50 800 70 50 7 49 0.844 0.023 18.5 Comparative Example 8 52 74 300 100 650 50 800 100 51 10 70 0.805 0.015 10.3 Invention Example 9 51 72 300 100 700 50 800 100 68 10 70 0.811 0.018 8.4 Invention Example 10 51 73 300 200 700 50 800 200 83 20 140 0.814 0.020 9.4 Invention Example 11 32 75 300 80 550 50 800 50 50 5 35 0.881 0.027 15.3 Comparative Example 12 30 74 300 80 600 50 800 52 50 5 36 0.877 0.026 15.6 Comparative Example 13 29 72 300 80 650 50 800 65 50 7 46 0.883 0.020 15.9 Comparative Example 14 31 73 300 80 700 50 800 80 55 8 56 0.840 0.022 10.8 Invention Example 15 32 72 300 80 800 - 800 80 80 8 56 0.888 0.102 7.5 Comparative Example 16 33 75 300 100 600 20 800 23 20 2 16 0.872 0.030 14.9 Comparative Example 17 28 73 300 100 650 20 800 38 20 4 27 0.870 0.023 14.5 Comparative Example 18 25 73 300 100 700 20 800 100 21 10 70 0.847 0.019 11.0 Invention Example 19 25 71 300 300 650 20 800 43 20 4 30 0.865 0.022 14.1 Comparative Example 20 32 74 300 300 700 20 800 300 23 30 210 0.863 0.021 14.7 Comparative Example Note) NA : Nitrogen amount precipitated after final cold rolling (massppm)
NB : Nitrogen amount precipitated after primary recrystallization annealing (massppm)
S1=Heating rate (°C/sec) from 500+2(NB-NA) to 600+2(NB-NA))
S2=Heating rate (°C/sec) from 600+2(NB-NA) to 750°C - A steel slab having a chemical composition shown in Table 2 and Table 3 is heated at 1400°C for 20 minutes, hot rolled to obtain a hot rolled sheet of 2.0 mm in thickness, subjected to a hot band annealing at 1000°C for 1 minute, cold rolled to obtain an intermediate cold rolled sheet of 1.5 mm in thickness, subjected to an intermediate annealing at 1100°C for 2 minutes, cold rolled to obtain a final cold rolled sheet having a thickness of 0.23 mm, and then subjected to a magnetic domain subdividing treatment by forming linear grooves through electrolytic etching.
- Next, the cold rolled sheet is heated to 750°C at a heating rate shown in Table 2 and Table 3 in a non-oxidizing atmosphere, and heated from 750°C to 840°C at an average heating rate of 10°C/sec, and then subjected to a primary recrystallization annealing combined with decarburization by keeping the sheet in an atmosphere of PH2O/PH2 = 0.3 for 2 minutes. Thereafter, an aqueous slurry of an annealing separator composed mainly of MgO and added with 10 mass% of TiO2 is applied and dried on the surface of the steel sheet after the primary recrystallization, and the sheet is wound in a coil, subjected to a final annealing, and subjected to a flattening annealing for the purpose of applying and baking a phosphate-based insulation tension coating and flattening the steel sheet to thereby produce a product sheet.
- In the production process, N amount precipitated in the steel sheet after the cold rolling NA and N amount precipitated in the steel sheet after the primary recrystallization NB are determined by analyzing the test specimens cut out from longitudinal end portions and widthwise central portion of the coil.
- 30 Epstein test pieces each having mass of not less than 500 g are taken out from each of the thus obtained product coils at a constant interval in the longitudinal direction thereof and iron loss W17/50 is measured over a full length of the coil to determine a best value of iron loss in the full length of the coil and a ratio of a portion having iron loss W17/50 of not more than 0.8 W/kg to the full length of the coil (achievement ratio: %). The results are also shown in Table 2 and Table 3.
- As seen from Table 2 and Table 3, the sheets of Invention Examples heated under the conditions according to the invention are good in the worst value of iron loss W17/50 and high in the ratio of the portion having iron loss W17/50 of not more than 0.80 w/kg (achievement ratio).
Table 3 No. Chemical composition (mass%) N amount precipitated (massppm) Heating rate(°C/s) Iron loss W17/50 Remarks C Si Mn S Se sol. Al N Others NA NB ∼600°C 600∼ 750°C S1 S2 S1× 0.1 S1× 0.7 Best value (W/kg) Achievement date (%) 13 0.03 3.05 0.05 0.0030 0.0160 0.0320 0.0150 - 122 138 120 70 105 70 11 74 0.783 75 Invention Example 14 0.03 3.05 0.05 0.0030 0.0160 0.0320 0.0150 - 125 136 100 70 91 70 9 64 0.790 30 Comparative Example 15 0.03 3.05 0.05 0.0030 0.0160 0.0320 0.0150 Bi:0.001 120 140 120 70 102 70 10 71 0.780 80 Invention Example 16 0.03 3.05 0.05 0.0030 0.0160 0.0320 0.0150 Ti:0.01 119 138 120 70 103 70 10 72 0.782 85 Invention Example 17 0.03 3.05 0.05 0.0030 0.0160 0.0320 0.0150 P:0.008 126 139 120 70 108 70 11 76 0.783 85 Invention Example 18 0.03 3.05 0.05 0.0030 0.0160 0.0320 0.0150 Nb:0.0010 124 137 120 70 108 70 11 76 0.778 80 Invention Example Note) NA : Nitrogen amount precipitated after final cold rolling (massppm)
NB : Nitrogen amount precipitated after primary recrystallization annealing (massppm)
S1=Heating rate (°C/sec) from 500+2(NB-NA) to 600+2(NB-NA))
S2=Heating rate (°C/sec) from 600+2(NB-NA) to 750°C - Moreover, when N in steel is not actively increased (not nitrided) in the primary recrystallization as in this example, it may be considered that all of the N amount in the steel slab is precipitated after the primary recrystallization annealing. In the actual operation, therefore, if the N amount precipitated after the cold rolling (before the primary recrystallization annealing) becomes clear, it is possible to set appropriate heating rate patterns. Also, if the production condition such as annealing pattern before the final cold rolling or the like is constant, it is possible to estimate N amount precipitated in the steel sheet after the cold rolling based on preliminary research.
- The technique of the invention is applicable to improve textures of non-oriented electrical steel sheets or to improve textures of thin steel sheets.
Claims (3)
- A method of producing a grain-oriented electrical steel sheet which comprises a series of steps of hot rolling a steel slab having a chemical composition of C: 0.001∼0.10 mass%, Si: 1.0∼5.0 mass%, Mn:0.01∼0.5 mass%, sol. Al: 0.003∼0.050 mass%, N: 0.0010∼0.020 mass%, one or two selected from S and Se: 0.005∼0.040 mass% in total, and the remainder being Fe and inevitable impurities, subjecting the resulting sheet to a hot band annealing if necessary, conducting a single cold rolling or two or more cold rollings with an intermediate annealing therebetween to form a cold rolled sheet having a final thickness, conducting a primary recrystallization annealing, applying an annealing separator, and conducting a final annealing, characterized in that in a heating process of the primary recrystallization annealing, a heating rate S1 from a temperature T1 to a temperature T2, which are determined by the following equations (1) and (2):
- The method of producing a grain-oriented electrical steel sheet according to claim 1, wherein a total N content in the steel slab NB'(massppm) is used instead of the N amount precipitated after the primary recrystallization annealing NB (massppm).
- The method of producing a grain-oriented electrical steel sheet according to claim 1 or 2, wherein the steel slab contains one or more selected from Cu: 0.01∼0.2 mass%, Ni: 0.01∼0.5 mass%, Cr: 0.01∼0.5 mass%, Mo: 0.01∼0.5 mass%, Sb: 0.01∼0.1 mass%, Sn: 0.01∼0.5 mass%, Bi: 0.001∼0.1 mass%, P: 0.001∼0.05 mass%, Ti: 0.005∼0.02 mass% and Nb: 0.0005∼0.0100 mass% in addition to the above chemical composition.
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PCT/JP2012/073608 WO2013039193A1 (en) | 2011-09-16 | 2012-09-14 | Process for producing grain-oriented electromagnetic steel sheet with excellent core loss characteristics |
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EP2770075B1 (en) * | 2011-10-20 | 2018-02-28 | JFE Steel Corporation | Grain-oriented electrical steel sheet and method of producing the same |
RU2600463C1 (en) * | 2012-09-27 | 2016-10-20 | ДжФЕ СТИЛ КОРПОРЕЙШН | Method of making plate from textured electrical steel |
BR112016026571B1 (en) * | 2014-05-12 | 2021-03-30 | Jfe Steel Corporation | METHOD FOR THE PRODUCTION OF GRAIN-ORIENTED ELECTRIC STEEL SHEETS |
WO2015174361A1 (en) | 2014-05-12 | 2015-11-19 | Jfeスチール株式会社 | Method for producing oriented electromagnetic steel sheet |
JP6319605B2 (en) * | 2014-10-06 | 2018-05-09 | Jfeスチール株式会社 | Manufacturing method of low iron loss grain oriented electrical steel sheet |
WO2019013354A1 (en) * | 2017-07-13 | 2019-01-17 | 新日鐵住金株式会社 | Oriented electromagnetic steel plate |
KR102044321B1 (en) * | 2017-12-26 | 2019-11-13 | 주식회사 포스코 | Grain oriented electrical steel sheet method for manufacturing the same |
JP7214974B2 (en) * | 2018-03-30 | 2023-01-31 | 日本製鉄株式会社 | Manufacturing method of grain-oriented electrical steel sheet |
KR102164329B1 (en) * | 2018-12-19 | 2020-10-12 | 주식회사 포스코 | Grain oriented electrical steel sheet and method for manufacturing therof |
CN112391512B (en) * | 2019-08-13 | 2022-03-18 | 宝山钢铁股份有限公司 | High magnetic induction oriented silicon steel and manufacturing method thereof |
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BE789262A (en) | 1971-09-27 | 1973-01-15 | Nippon Steel Corp | PROCESS FOR FORMING AN INSULATING FILM ON A SILICON ORIENTED STEEL STRIP |
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US4898626A (en) * | 1988-03-25 | 1990-02-06 | Armco Advanced Materials Corporation | Ultra-rapid heat treatment of grain oriented electrical steel |
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DE69706388T2 (en) * | 1996-10-21 | 2002-02-14 | Kawasaki Steel Co | Grain-oriented electromagnetic steel sheet |
JP3456862B2 (en) | 1997-04-25 | 2003-10-14 | 新日本製鐵株式会社 | Manufacturing method of grain-oriented electrical steel sheet with extremely low iron loss |
JP3386751B2 (en) * | 1999-06-15 | 2003-03-17 | 川崎製鉄株式会社 | Method for producing grain-oriented silicon steel sheet with excellent coating and magnetic properties |
DE69913624T2 (en) * | 1998-09-18 | 2004-06-09 | Jfe Steel Corp. | Grain-oriented silicon steel sheet and manufacturing process therefor |
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JP3537339B2 (en) | 1999-01-14 | 2004-06-14 | 新日本製鐵株式会社 | Grain-oriented electrical steel sheet having excellent film properties and magnetic properties and method for producing the same |
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CN101454465B (en) * | 2006-05-24 | 2011-01-19 | 新日本制铁株式会社 | Process for producing grain-oriented magnetic steel sheet with high magnetic flux density |
JP4840518B2 (en) * | 2010-02-24 | 2011-12-21 | Jfeスチール株式会社 | Method for producing grain-oriented electrical steel sheet |
JP5760590B2 (en) * | 2011-03-30 | 2015-08-12 | Jfeスチール株式会社 | Method for producing grain-oriented electrical steel sheet |
EP2770075B1 (en) * | 2011-10-20 | 2018-02-28 | JFE Steel Corporation | Grain-oriented electrical steel sheet and method of producing the same |
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