EP0577124B1 - Kornorientiertes Elektroblech mit hoher Flussdichte und geringen Eisenverlusten und Herstellungsverfahren - Google Patents

Kornorientiertes Elektroblech mit hoher Flussdichte und geringen Eisenverlusten und Herstellungsverfahren Download PDF

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Publication number
EP0577124B1
EP0577124B1 EP93110517A EP93110517A EP0577124B1 EP 0577124 B1 EP0577124 B1 EP 0577124B1 EP 93110517 A EP93110517 A EP 93110517A EP 93110517 A EP93110517 A EP 93110517A EP 0577124 B1 EP0577124 B1 EP 0577124B1
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Prior art keywords
steel sheet
annealing
flux density
magnetic flux
iron loss
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EP93110517A
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English (en)
French (fr)
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EP0577124A3 (en
EP0577124A2 (de
Inventor
Osamu c/o Nippon Steel Corp. Yawata Tanaka
Katsuro c/o Nippon Steel Corp. Yawata Kuroki
Maremizu c/o Nippon Steel Corp. Yawata Ishiba
Hiroaki c/o Nippon Steel Corp. Yawata Masui
Tsutomu c/o Nippon Steel Corp. Yawata Haratani
Yoshio c/o Nippon Steel Corp. Yawata Nakamura
Hotaka c/o Nippon Steel Corp. Yawata Honma
Yoichi c/o Nippon Steel Corp. Yawata Mishima
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Nippon Steel Corp
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Nippon Steel Corp
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Publication date
Priority claimed from JP4175790A external-priority patent/JP2691828B2/ja
Priority claimed from JP4206795A external-priority patent/JPH0649654A/ja
Priority claimed from JP4220500A external-priority patent/JP2671084B2/ja
Priority claimed from JP4284787A external-priority patent/JPH06136552A/ja
Priority claimed from JP30272892A external-priority patent/JP2671088B2/ja
Priority claimed from JP4340746A external-priority patent/JPH06188116A/ja
Application filed by Nippon Steel Corp filed Critical Nippon Steel Corp
Publication of EP0577124A2 publication Critical patent/EP0577124A2/de
Publication of EP0577124A3 publication Critical patent/EP0577124A3/en
Publication of EP0577124B1 publication Critical patent/EP0577124B1/de
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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
    • C21D8/1277—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties involving a particular surface treatment
    • C21D8/1283—Application of a separating or insulating coating
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
    • H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
    • H01F1/147—Alloys characterised by their composition
    • H01F1/14766—Fe-Si based alloys
    • H01F1/14775—Fe-Si based alloys in the form of sheets
    • H01F1/14783—Fe-Si based alloys in the form of sheets with insulating coating
    • 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
    • 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
    • C21D8/1255—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 with diffusion of elements, e.g. decarburising, nitriding
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • 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
    • 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
    • C21D8/1294—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties involving a localized treatment

Definitions

  • the present invention relates to a grain oriented electrical steel sheet not having a glass film (a forsterite film) and particularly to a grain oriented electrical steel sheet having a high magnetic flux density and an ultra low iron loss and remarkably excellent workability, such as slittability, cuttability and punchability, and a process for producing the same.
  • Grain oriented electrical steel sheets are used mainly as an iron core material for transformers and other electrical equipment and should be excellent in magnetic properties, such as inductions and an iron loss property.
  • the orientation of grains has been remarkably improved by a method characterized by a high reduction ratio in final cold rolling wherein AlN and MnS are used as an inhibitor, so that, at the present time, it has become possible to provide steel sheets having a magnetic flux density close to the theoretical value.
  • film properties and workability in addition to magnetic properties are important to the use of grain oriented electrical steel sheets by customers.
  • grain oriented electrical steel sheets are treated with a film having a double layer structure comprising a glass film formed in the final box annealing and an insulating film.
  • the glass film is composed mainly of forsterite (Mg 2 SiO 4 ) that is a product of a reaction of MgO as an annealing separator with SiO 2 formed during decarburization annealing.
  • This ceramic film is hard and highly resistant to abrasion and has a significant adverse effect on durability of tools used in working of electrical steel sheets, such as slitting, cutting and punching.
  • tools used in working of electrical steel sheets such as slitting, cutting and punching.
  • slitting, cutting and punching For example, when grain oriented electrical steel sheets having a glass film are subjected to punching, there occurs abrasion of molds and the occurrence of burr in the sheet at the time of punching becomes significant after effecting the punching about several thousand times, which leads to problems of use.
  • a process for producing a grain oriented electrical steel sheet not having a glass film is disclosed, for example, in JP-A-53-22113.
  • the thickness of an oxide film is brought to 3 ⁇ m or less in the decarburization annealing, particular alumina containing 5 to 40% of a hydrous silicate mineral powder is used as an annealing separator, and final annealing is effected with this annealing separator coated on the steel sheet.
  • this method reduces the thickness of the oxide film, enables an easily removable glass film to be formed by virtue of the incorporation of the hydrous silicate mineral and provides a steel sheet having a metallic gloss.
  • JP-A-56-65983 discloses a technique wherein an annealing separator comprising aluminum hydroxide and, incorporated therein, 20 parts by weight of an additive for removing impurities and 10 parts by weight of an inhibitor is coated on a steel sheet to form a thin glass film having a thickness of 0.5 ⁇ m or less.
  • JP-A-59-96278 proposes an annealing separator comprising Al 2 O 3 , which is less reactive with SiO 2, as an oxide layer formed in the decarburization annealing and MgO which has an activity lowered by sintering at a high temperature of 1,300°C or above. According to the description of the specification, the proposed annealing separator can inhibit the formation of forsterite.
  • EP-A-0 305 966 discloses a method for producing glassless grain-oriented electrical steel sheet using no AlN as inhibitor and exhibiting metallic luster by applying an annealing separator consisting of magnesium blended with one or more salts of alkali metal or alkali or alkali-earth metal.
  • EP-A-0 420 238 discloses a process for preparing a grain-oriented steel sheet having high magnetic flux density, in which nitriding is performed and a glass coating is formed in the final products.
  • An object of the present invention is to provide a grain oriented electrical steel sheet having a high magnetic flux density and an ultra low iron loss, which grain oriented electrical steel sheet has excellent punchability, slittability, cuttability, etc. and substantially evenly free from a glass film, and a process for producing said steel sheet at a low cost on a commercial scale.
  • the most characteristic feature of the material according to the present invention resides in that the material is a grain oriented electrical steel sheet not having a glass film or having no significant glass film.
  • This characteristic feature leads to two effects. One is that the workability, such as slittability, cuttability or punchability, is excellent. Since the glass film comprises a hard ceramic, it accelerates the abrasion of working tools and reduces the workability. The second effect is to reduce the iron loss after the refining of the magnetic domain. The iron loss is divided into a hysteresis loss as a dc component and an eddy current loss as an ac component. The eddy current loss can be decreased by reducing the sheet thickness.
  • the mechanism for reducing the iron loss of the material according to the present invention is that the material has no glass film and has a smooth interface.
  • the iron losses become lower with increasing B 8 value (i.e., magnetic flux density at a magnetizing force of 800 A/m).
  • B 8 value i.e., magnetic flux density at a magnetizing force of 800 A/m.
  • mere increase in the B 8 value does not result in a lowering of the iron loss.
  • an increase in the B 8 value gives rise to an increase in the width of the magnetic refining in turn increases the abnormal eddy current loss.
  • This effect becomes significant with an increase in the smoothness of the surface of the steel sheet. For this reason, in order to sufficiently attain the effect of reducing the iron loss in the material according to the present invention, it is necessary to enhance the B 8 value and, at the same time, to use a technique for decarburization the magnetic domain.
  • the amount of an oxide layer formed on the surface of the steel sheet after final box anealing is minimized. This is because the oxide layer derived from the decarburization annealing causes the occurrence of a reaction of magnesia, as an annealing separator, to form a glass film.
  • additives including Cl compounds are added to the annealing separator. These additives have a feature that they form a glass film during final box annealing and then remove the glass film.
  • a further method for enhancing the B 8 value is to increase the partial pressure of nitrogen in the finish-annealing atmosphere.
  • This is the third characteristic feature of the present invention.
  • the present invention is based on the assumption that nitrides are used as the inhibitor.
  • weakening of the inhibitor attributable to denitriding is the greatest problem in the step of rendering the material glassless.
  • the presence of a glass film in the course of the secondary recrystallization as described above in connection with the second characteristic feature is a measure for preventing denitriding, it is necessary to maintain the partial pressure of nitrogen in the final box annealing atmosphere at a certain value or higher for the purpose of further reinforcing this effect.
  • inhibitor elements for example, Al, N, Mn and S
  • the material is nitrided in a strong reducing atmosphere after decarburization annealing to form an inhibitor composed mainly of (Al, Si)N, and a good secondary recrystallization is developed in final box annealing, followed by the division of the magnetic domain.
  • the process for producing the grain oriented electrical steel sheet having a high magnetic flux density and not having a glass film according to the present invention using a starting material having the above-described composition and the above-described steps is characterized by a series of treatments conducted between decarburization annealing and final box annealing.
  • the material subjected to cold rolling to a final sheet thickness is subjected to decarburization annealing in a continuous line.
  • decarburization annealing C in the steel is removed, and primary recrystallization is effected.
  • an oxide film composed mainly of SiO 2 is formed on the surface of the steel sheet.
  • the degree of oxidation of the steel sheet is the first characteristic feature of the present invention, wherein the oxygen content is 900 ppm or less, and an Fe-oxides to SiO 2 ratio is 0.20 or less.
  • the decarburization annealing is effected at 800 to 875°C in an atmosphere comprising N 2 and H 2 while controlling the dew point. Subsequently, in the second half of the decarburization annealing or after the completion of the decarburization annealing or in both the above-described stages, a nitriding treatment is effected in the same line or a separately provided line.
  • the optimal nitrogen content is 150 ppm or more, preferably 150 to 300 ppm although it depends upon the primary recrystallized grain diameter.
  • the material is coated with an annealing separator, dried, coiled and subjected to final box annealing.
  • the composition of the annealing separator is the second characteristic feature of the present invention and plays an important role in the formation and regulation of a glass film and the decomposition reaction of the glass film.
  • MgO has a particle size distribution such that 30% or more of the MgO consists of particles having a diameter of 10 ⁇ m or less. Further, it should have a CAA value of 50 to 300 sec and a hydrated water content of 5% or less. Further, a compound composed mainly of a Cl compound is used as an additive to the MgO.
  • the Cl compound underlies the invention of the instant application in that it serves to remove the glass film formed during the final finish annealing.
  • the glass film serves to regulate a nitriding reaction and a denitriding reaction during the final box annealing and to regulate the inhibitor content of the steel sheet. Therefore, mere formation of a glass film cannot provide the development of good secondary recrystallized grains, so that it is impossible to attain the iron losses reduction effect derived from a smooth steel sheet interface.
  • the Cl compound accelerates a reaction of SiO 2, formed on the surface of the steel sheet in the decarburization annealing, with MgO, as the annealing separator, to form a glass film at a lower temperature than that usually necessary for the formation of the glass film, and then forms a chloride of iron at the interface of the film and the matrix to remove the film.
  • the final box annealing conditions are important to the present invention.
  • annealing atmosphere conditions are an important factor for stabilizing the secondary recrystallization and increasing the magnetic flux density when, like the present invention, use is made of the step of effecting a nitriding treatment after decarburization annealing to form an inhibitor composed mainly of (Al, Si)N and regulating the formation of a glass film and causing a decomposition reaction of the glass film by using an annealing separator and final finish annealing conditions.
  • the secondary recrystallization initiates at about 1,100°C which is higher than that in the case of the conventional process for producing a grain oriented electrical steel sheet having a high magnetic flux density. For this reason, it is necessary to maintain the strength of the inhibitor at a constant level while effecting the inhibition of formation of the glass film and the decomposition reaction of the glass film until the temperature reaches the secondary recrystallization initiation region.
  • the temperature is raised in an atmosphere having a N 2 content of 30% or more until it reaches the soaking temperature.
  • This enables (Al, Si)N to be stabilized until the secondary recrystallization begins.
  • the heating rate in the final box annealing is 20°C/hr or less. When it exceeds 20°C/hr, the growth rate of secondary recrystallization becomes improper, which deteriorates the integration density in the orientation of the product, so that a satisfactorily high B 8 value cannot be obtained.
  • the steel sheet subjected to final box annealing is then subjected to baking with an insulating coating solution and heat flattening combined with shape reforming and stress relieving annealing in a continuous annealing line at 800 to 900°C.
  • a seam or spotty recess having a depth of 5 to 50 ⁇ m is imported at intervals of 2 to 15 mm in a direction at an angle of 45 to 90° to the rolling direction by a laser beam, a sprocket roll, a press, marking, local etching, etc.
  • various insulating coating solution are coated according to applications on the part of the customers, and the coated material is subjected to a baking treatment.
  • the steel sheet is coated with a coating solution comprising a phosphate or colloidal silica as described in JP-B-53-28375 and then subjected to a baking treatment.
  • a coating solution comprising a phosphate or colloidal silica as described in JP-B-53-28375
  • the surface of the steel sheet subjected to heat flattening is coated with an organic coating solution or a semi-organic coating solution and then subjected to a baking treatment.
  • the surface of the steel sheet subjected to heat flattening may be coated with an inorganic coating solution, subjected to a baking treatment and then coated with an organic coating solution and subjected to a baking treatment to form a film having a double layer structure.
  • the organic film forming agent When use is made of the organic film forming agent, (1) at least one totally organic coating solution selected from acrylic, polyvinyl, vinyl acetate, epoxy, styrene and other resins and/or their polymers and crosslinking products, or (2) a semi-organic coating solution comprising a mixture of the resin recited in the above item (1) with at least one member selected from chromates, phosphoric acid, phosphates, boric acid, borates, etc. is coated and baked at a temperature in the range of from 150 to 450°C to a thickness of 2 to 6 ⁇ m before use of the steel sheet.
  • the coating and baking treatment with these organic coating solution contributes to a remarkable improvement in the slittability, cuttability, punchability, etc.
  • the punchability the conventional products having a glass film can be punched about 5000 times when use is made of a steel die.
  • the punchability can be improved to about 100,000 times when an inorganic insulating coating solution agent is coated and baked, and to about 2,000,000 times when a semi-organic film forming agent is further coated and baked thereon.
  • the secondary recrystallization becomes so unstable that the magnetic flux density of the product is as low as about 1.80 Tesla in terms of the B 8 value even in the case of successful secondary recrystallization.
  • the C content exceeds 0.075%, the decarburization annealing time should be prolonged, so that the productivity is lowered.
  • the specific resistance of the product varies depending upon the Si content.
  • the Si content is less than 2.5%, satisfactory iron loss value is not obtained.
  • it exceeds 4.5% cracking and breaking of the material frequently occur during cold rolling, which makes it impossible to stably effect the cold rolling operation.
  • One of the characteristic features of the composition system of the starting material according to the present invention is to limit the S content to 0.014% or less.
  • S sulfur
  • MnS a precipitate necessary for inducing secondary recrystallization
  • content range capable of exhibiting the best effect, which content range has been specified as an amount range capable of dissolving, in a solid solution form, MnS at the stage of heating the slab prior to the hot rolling.
  • (Al, Si)N as a precipitate necessary for the secondary recrystallization.
  • the acid-soluble Al content and N content it is necessary for the acid-soluble Al content and N content to be 0.010% or more and 0.0030% or more, respectively.
  • the acid-soluble Al content exceeds 0.040%, the AlN content during hot rolling become improper, which renders the secondary recrystallization unstable. For this reason, the acid-soluble Al content is limited to 0.010 to 0.040%.
  • the N content exceeds 0.0130%, not only there occurs surface cracking called "blister" on the surface of the steel sheet but also the primary recrystallized grain diameter cannot be regulated. For this reason, the N content is limited to 0.0030 to 0.0130%.
  • the Mn content is less than 0.05%, the secondary recrystallization becomes unstable.
  • the B 8 value becomes high, the use of Mn in an amount exceeding a certain value is disadvantageous from the viewpoint of cost. For this reason, the Mn content is limited to 0.05 to 0.45%.
  • the decarburization annealing according to the present invention should satisfy requirements that the oxygen content should be 900 ppm or less and the Fe-oxides to SiO 2 ratio is 0.20 or less.
  • the oxygen content exceeds 900 ppm, the SiO 2 and Fe-oxides contents inevitably increase and the thickness of the oxide film as well becomes large, which is disadvantageous for the glass film decomposition reaction in the final box annealing.
  • SiO 2 remains just under the surface, which weakens the effect of improving the workability or makes it impossible to bring the surface to a completely specular glassless state. Further, this is causative of the deterioration of the magnetic properties.
  • the formation of excessive SiO 2 accelerates the decomposition of AlN etc.
  • the degree of oxidation is preferably in the range of from 400 to 700 ppm in terms of the oxygen content.
  • the P content of the product is important to the present invention. P is dissolved in a solid solution form in iron, and part thereof is present in a precipitated state. The P is very useful for reducing the iron loss of the product, and in order to attain the effect, it is necessary for the P content to be 0.03% at the lowest. On the other hand, the P content exceeds 0.15%, the product becomes fragile, which is detrimental to the workability of the product, for example, punchability, so that the product is unsuitable for use.
  • the Fe-oxides to SiO 2 ratio in the oxide film is limited to 0.20 or less.
  • this ratio exceeds 0.20, since the glass film formation reaction is remarkably accelerated in the first half of the finish annealing, the amount of formation of the forsterite is increased, which inhibits the reaction in the subsequent step of decomposing the forsterite from sufficiently proceeding.
  • the FeO to SiO 2 ratio is 0.20 or less, it is possible to provide a steel sheet having substantially no glass film. after the completion of the finish annealing by virtue of effects attained, for example, by the addition of additives to MgO.
  • the nitrogen content of the steel sheet after the completion of the decarburization annealing is limited to 150 ppm or more. This requirement should be satisfied for the purpose of forming the inhibitor (Al, Si)N necessary for stably providing good secondary recrystallized grains in the process of the present invention.
  • the nitrogen content is less than 150 ppm, the secondary recrystallization becomes so unstable that fine grains are liable to occur.
  • the nitrogen content exceeds 300 ppm, roughness and unevenness occurs in the surface of the steel sheet in subsequent reactions, such as a denitriding reaction, or such a high nitrogen content often becomes disadvantageous in the step of purification after that. For this reason, it is desirable for the nitrogen content to be 300 ppm or less.
  • MgO used in the annealing separator there is a limitation on the particle diameter, CAA value and hydration ig-loss.
  • the material is rendered glassless by decomposing and removing, through a chemical reaction, a moderate glass film formed in the first half of the temperature rise in the final box annealing.
  • a chemical reaction e.g., a chemical reaction to stabilize the inhibitor until the initiation of the secondary recrystallization in the first half of the final box annealing.
  • the MgO as themain component of the annealing separator it is important for the MgO as themain component of the annealing separator, as such, to have a suitable reactivity. Specifically, when the reactivity of MgO is very low, the reaction for the formation of the forsterite in the first half of the temperature rise in the final box annealing does not proceed, so that sealing effect cannot be attained by the film. In this case, even in the case of successful secondary recrystallization, the crystal orientation becomes very poor, or additional oxidation causes residual SiO 2 , Al 2 O 3 or their spinel to occur just under the surface of the steel sheet, which deteriorates the iron losses.
  • MgO is limited to have such a particle size distribution such that 30% or more of the MgO particles have a diameter of 10 ⁇ m or less.
  • this proportion is less than 30%, the reactivity becomes so low that the above-described effect cannot be attained.
  • the CAA value of MgO is limited to 50 to 300 sec. When this value is less than 50 sec, the progress of the hydration becomes very rapid for use on a commercial scale, so that it becomes difficult to control the hydration ig-loss.
  • the CAA value exceeds 300 sec, the reactivity of the MgO particles becomes so low that it becomes impossible to form a moderate forsterite in the first half of the final box annealing.
  • the hydration ig-loss of MgO is limited to 5% or less.
  • the dew point between steel sheets becomes so high that additional oxidation occurs in the first half of the temperature rise, which makes it difficult to render the surface of the steel sheet homogeneously glassless. In extreme cases, this has an influence even on the inhibitor, which aggravates the poor secondary recrystallization.
  • At least one member selected from chlorides, carbonates, nitrates, sulfates and sulfides of Li, K, Bi, Na, Ba, Ca, Mg, Zn, Fe, Zr, Sn, Sr, Al, etc. is incorporated in an amount of 2 to 30 parts by weight based on 100 parts by weight of MgO.
  • the addition of these compounds first causes a moderately thin forsterite film to be formed on the surface of the steel sheet in the first half of the temperature rise in the finish annealing. Then, the formation of the forsterite is inhibited, and additional oxidation is prevented.
  • the film layer is decomposed by an Fe etching reaction in the film layer, thus rendering the surface of the steel sheet glassless.
  • the amount of addition of these compounds is less than 2 parts by weight, the decomposition reaction of the forsterite formed in the first half of the temperature rise does not sufficiently proceed, so that the glass film unfavorably remains unremoved.
  • the amount of addition of the above-described compounds exceeds 30 parts by weight, component elements in the additive unfavorably diffuse and penetrate into the steel sheet to give rise to intergranular etching or to have an influence on the inhibitor or on subsequent purification treatment.
  • the amount of addition is particularly preferably in the range of from 5 to 15 parts by weight.
  • Final box annealing conditions are very important to the process according to the present invention wherein the formation of a moderate glass film and the decomposition of the glass film are effected in the final box annealing.
  • N 2 , H 2 or a mixed gas comprising N 2 and H 2 is used as the atmosphere gas in the final box annealing of grain oriented electrical steel sheets.
  • the use of a mixed gas comprising N 2 and H 2 is advantageous from the viewpoint of the regulation of oxidation on the surface of the steel sheet and the cost.
  • an atmosphere having a N 2 content of at least 30% or more and comprising N 2 , H 2 and another inert gases is used as an atmosphere gas during the temperature rise.
  • the partial pressure of N 2 is less than 30%, the effect of preventing the weakening of (Al, Si)N caused during the reaction for rendering the surface of the steel sheet glassless cannot be attained, so that a material having a high magnetic flux density cannot be stably provided.
  • the deterioration of the magnetic properties is significant particularly under such an atmosphere condition that the N 2 content is 20% or less.
  • the atmosphere comprises 100% of N 2 , in some property values, oxidation occurs due to an increase in the degree of oxidation between steel sheets, which often causes the surface of the steel sheet to become uneven.
  • the N 2 content is preferably in the range of from 30 to 90%.
  • the soaking temperature in the final box annealing is in the range of from 1180 to 1250°C.
  • the material is in a glassless state at a point of time when the temperature has reached the soaking temperature in the final box annealing.
  • the exposure of the material to the soaking temperature gives rise to further thermal etching, which renders the surface of the steel sheet specular.
  • the soaking temperature is below 1180°C, not only is this effect small but also the purification is disadvantaged.
  • the soaking temperature exceeds 1250°C the effect of rendering the surface of the steel sheet specular is limited and there is a possibility that the form of the coil becomes poor and seizing occurs in the edge portion.
  • the heating rate in the final box annealing is limited to 20°C/hr or less.
  • the decomposition rate of the inhibitor exceeds the growth rate of the secondary recrystallized grain, which inhibits the growth of crystal grains having an optimal orientation, so that the B 8 value falls.
  • the resultant steel sheet is coated with an insulating coating solution and subjected to heat flattening.
  • a seam or spotty flaw, recess or groove is imparted to the surface of the steel sheet by a laser beam, a sprocket roll, a press, marking, local etching or the like before or after the heat flattening.
  • the conditions of the flaw, recess, or groove vary depending upon the usage of electrical steel sheets.
  • the depth may be as small as less than 5 ⁇ m for the purpose of utilizing the effect attained by a suitable strain.
  • the flaw, recess or groove conditions are important.
  • the flaw, recess or groove is imparted in a depth of 5 to 50 ⁇ m at intervals of 2 to 15 mm and an angle of 45 to 90° to the rolling direction. The angle is preferably as close to 90° as possible.
  • the effect of provision of the flaw, recess or groove can be attained when the angle is 45° or more.
  • the width of the flaw, recess or groove is not particularly limited, it is preferably as narrow as possible.
  • the depth is less than 5 ⁇ m, the effect of improving the iron loss value after annealing is small.
  • the depth exceeds 50 ⁇ m the lowering in the magnetic flux density becomes large, which is disadvantageous from the viewpoint of properties at a high magnetic field.
  • the direction of the seam flaw is outside the above-described range, the effect of improving the iron loss cannot be attained, or there occurs a deterioration in the iron loss.
  • an inorganic, organic or semi-organic coating solution agent or the like is used as an insulating coating solution forming agent for coating and baking depending upon the purpose of use of the electrical steel sheet.
  • the steel sheet is subjected to coating and baking with a treating agent composed mainly of colloidal silica and a phosphate or a treating agent consisting of a phosphate alone.
  • the coating thickness is limited to 2 to 6 ⁇ m. When the thickness is smaller than this range, no effect is attained. On the other hand, when the thickness exceeds this range, the lowering in the space factor causes properties to be lost when the product is incorporated into a transformer.
  • the steel sheet is subjected to coating and baking with an inorganic, organic or semi-organic coating solution agent once or twice or more.
  • a suitable amount of a glass film is formed in the first half of the step of the temperature rise in the final box annealing through the utilization of a suitable amount of an oxide film having a regulated reactivity formed in the decarburization annealing, MgO having a regulated reactivity and additives.
  • MgO having a regulated reactivity and additives.
  • This imparts a suitable sealing effect to the surface of the steel sheet, which contributes to stabilization of inhibitors such as AlN.
  • etching and decomposition reaction of the glass film proceeds by virtue of the action of additives incorporated into MgO, such as chlorides, carbonates, sulfates, nitrates and sulfides.
  • This effect is believed to reside in the following fact.
  • Two effects i.e., an effect derived from the freedom from a glass film and an internal oxide layer observed in products having a glass film and an effect refinning from the smooth surface having a low unevenness, prevent the occurrence of a pinning phenomenon in the movement of the domain wall during division of the magnetic domain. This combines with the effect of a high magnetic flux density to provide a significant effect, so that a material having an ultra low iron loss can be provided.
  • a steel comprising, in terms of by weight, 3.50% of Si, 0.054% of C, 0.14% of Mn, 0.008% of S, 0.0295% of Al and 0.073% of N with the balance consisting of Fe and unavoidable impurities was cast into a slab by continuous casting.
  • the slab was heated to 1,200°C, hot-rolled, annealed, pickled and cold-rolled into a sheet having a thickness of 0.22 mm which was then subjected to decarburization annealing for 110 sec. In this case, the decarburization annealing was effected on the two temperature levels of 830°C and 840°C.
  • the average grain diameter of the primary recrystallized grains and the proportion of grains having a diameter more than twice as large as the average grain diameter are shown in Fig. 2.
  • the steel sheets subjected to decarburization annealing were nitrided to have a nitrogen (N) content of 226 ppm, coated with an annealing separator comprising a chloride, a carbonate, a nitrate, a sulfate or the like and then subjected to final box annealing.
  • the high temperature final box annealing cycle was effected under two conditions shown in Figs. 1 (A) and 1 (B).
  • the steel sheets subjected to secondary recrystallization was mildly pickled with 2.5% sulfuric acid solution at 80°C for 10 sec, coated with an insulating coating solution agent comprising 50 kg of 50% Al(H 2 PO 4 ) 3 , 70 kg of 30% colloidal silica and 5 kg of CrO 3 , and then subjected to baking and heat flattening at 850°C for 30 sec. Thereafter, a strain was imparted to the steel sheets in the perpendicular direction to the rolling direction under conditions of intervals of 5 mm in the rolling direction, an irradiation width of 0.15 mm and an irradiation mark depth of 2.0 ⁇ m to provide final products.
  • the thickness of the oxide film on the surface of the steel sheet before coating with an insulating film was 0.3 ⁇ m or less, that is, the surface could be successfully rendered glassless.
  • the heating rate in the final box annealing was lowered, a very high B 8 value could be obtained by enhancing the N 2 partial pressure and lowering the decarburization annealing temperature.
  • a steel material comprising, in terms of by weight, 0.054% of C, 3.35% of Si, 0.12% of Mn, 0.032% of acid soluble Al, 0.007% of S and 0.0072% of N with the balance consisting of Fe and unavoidable impurities was hot-rolled into a sheet having a thickness of 1.6 mm, annealed at 1130°C for 2 min, pickled and cold-rolled into a sheet having a final thickness of 0.15 ⁇ m.
  • the steel sheet was subjected to decarburization annealing under conditions of 25% N 2 + 75% H 2 and a dew point of 65°C at 830°C for 70 sec, and nitrided in a dry atmosphere comprising 25% of N 2 , 75% of H 2 and NH 3 at 750°C for 30 sec to have a nitrogen (N) content of 220 ppm, thereby providing a material under test.
  • This steel sheet was coated with an annealing separator having a composition specified in Table 3, and final box annealing was effected with the atmosphere conditions being changed to those shown in Figs. 1 (A) and 1 (B).
  • This steel sheet was mildly pickled with 2% H 2 SO 4 at 80°C for 10 sec to activate the surface of the steel sheet.
  • the surface of the steel sheet was coated with an insulating coating solution comprising 100 ml of 20% colloidal SiO 2 , 25 ml of 50% monobasic aluminum phosphate, 25 ml of 50% monobasic magnesium phosphate and 7 g of chromic anhydride so that the thickness of the film after baking was 4 ⁇ m, and subjected to baking at 830°C for 30 sec to provide a product.
  • the surface appearance, coverage of glass film and magnetic properties of the steel sheets in this experiment are given in Table 4. Coating Conditions for Annealing Separator No.
  • the surface could be substantially completely rendered glassless and exhibited a metallic gloss, so that steel sheets having a specular surface could be provided.
  • the coverage of glass was 1 g/m 2 or less, that is, the glass film was hardly formed.
  • all the materials subjected to final box annealing under conditions (A) had a high magnetic flux density and a low iron loss value, whereas all the materials subjected to final box annealing under comparative conditions (B) were poor in secondary recrystallization and had poor magnetic properties. All the materials according to the present invention were far superior to the comparative materials in the repeated flexural property. Further, with respect to the number of times of punching as well, the materials according to the present invention exhibited remarkably excellent results.
  • Example 2 The same material as that used in Example 2 was subjected to the same treatment as that of Example 2 and hot-rolled into a sheet having a final thickness of 0.225 mm.
  • This steel sheet was subjected to decarburization annealing under conditions of 25% N 2 + 75% H 2 and a dew point of 65°C at 840°C for 90 sec, and subsequently annealed in a dry atmosphere comprising 25% of N 2 , 75% of H 2 and NH 3 at 750°C for 30 sec with the NH 3 content being varied to have a nitrogen (N) content of 200 ppm. Thereafter, the steel sheet was coated with an annealing separator having a composition specified in Table 5, and final box annealing was effected under conditions shown in Figs.
  • the surface could be significantly rendered glassless and exhibited a metallic gloss, and the coverage of the formed glass film was 1 g/m 2 or less.
  • all the materials coated with the annealing separator according to the present invention had good iron loss and magnetic flux density values. A particularly good iron loss value could be obtained when the film thickness was 3 ⁇ m or more.
  • the glassless materials according to the present invention exhibited a significantly lower value than the comparative material having a glass film.
  • the comparative material having a glass film was unsuccessful in the purification and had a poor iron loss value.
  • a steel material comprising, in terms of by weight, 0.054% of C, 3.35% of Si, 0.10% of Mn, 0.030% of acid soluble Al, 0.007% of S and 0.007% of N with the balance consisting of Fe and unavoidable impurities was hot-rolled into a sheet having a thickness of 2.0 mm, annealed at 1130°C for 2 min, pickled and cold-rolled into a sheet having a final thickness of 0.225 mm.
  • the steel sheet was subjected to decarburization annealing under conditions of 25% N 2 + 75% H 2 and a dew point of 55°C at 830°C for 100 sec, and nitrided in a dry atmosphere comprising 25% of N 2 , 75% of H 2 and NH 3 at 750°C for 30 sec to have a nitrogen (N) content of 250 ppm to provide a material under test.
  • decarburization annealing under conditions of 25% N 2 + 75% H 2 and a dew point of 55°C at 830°C for 100 sec
  • nitrided in a dry atmosphere comprising 25% of N 2 , 75% of H 2 and NH 3 at 750°C for 30 sec to have a nitrogen (N) content of 250 ppm to provide a material under test.
  • This steel sheet was coated with an annealing separator having a composition specified in Table 7, and final box annealing was effected with the atmosphere conditions being changed to those shown in Figs. 1 (A) and 1 (C).
  • This steel sheet was mildly pickled with 2% H 2 SO 4 at 80°C for 10 sec to activate the surface of the steel sheet.
  • the surface of the steel sheet was coated with an insulating coating solution agent comprising 80 ml of 20% colloidal SiO 2 , 20 ml of 20% colloidal ZrO 2 , 50 ml of 50% Al(H 2 PO 4 ) 3 and 7 g of CrO 3 so that the thickness of the film after baking was 4 ⁇ m, and subjected to baking at 830°C for 30 sec to provide a product.
  • MgS 5 pt.wt 22 Do. MgO 100 pt.wt. + NaCl 10 pt.wt. + FeS 10 pt.wt. 23 Comp.Ex. MgO 100 pt.wt. + TiO 2 5 pt.wt. + Na 2 B 4 O 7 0.3 pt.wt.
  • the surface could be substantially rendered completely glassless, and a good glassless uniform surface appearance could be obtained.
  • all the materials subjected to finish annealing under conditions (A) had a high magnetic flux density and a lower iron loss value than the comparative material having a glass film, whereas all the materials subjected to final box annealing under conditions (C) had an extremely low magnetic flux density and were a poor material.
  • All the materials according to the present invention were far superior in the surface roughness to the materials having a glass film, that is, it was confirmed that the surface appearance was improved by the present invention. Further, the materials according to the present invention exhibited a great improvement in the punchability as a measure for the evaluation of workability.
  • Example 4 The same material as that used in Example 4 was subjected to the same treatment as that of Example 4 and rolled into a sheet having a final thickness of 0.225 mm.
  • a seam flaw was imparted to the steel sheet by using a laser beam in the rolling direction and a direction normal to the rolling direction of the steel sheet under conditions of an interval of 5 mm, a depth of 5 ⁇ m and a width of 100 ⁇ m, and the steel sheet was then subjected to decarburization annealing under conditions of 25% N 2 + 75% H 2 at 830°C for 100 sec and nitrided in an atmosphere comprising 25% of N 2 , 75% of H 2 and NH 3 to have a nitrogen (N) content of 220 ppm.
  • N nitrogen
  • the steel sheet was coated with an annealing separator having a composition specified in Table 9, and final box annealing was effected under conditions shown in Fig. 1 (A).
  • the surface of the steel sheet was coated with an insulating film forming agent comprising 70 cc of 20% colloidal SiO 2 , 25 cc of 20% colloidal ZrO 2 , 5 cc of 20% colloidal SnO 2 , 50 cc of 50% monobasic magnesium phosphate and 5 g of CrO 3 and subjected to baking with the coating thickness being varied.
  • the results on the state of the film and magnetic properties in this experiment are given in Table 10.
  • No. Coating Conditions for Annealing Separator 24 Invention MgO 100 pt.wt.
  • the surface could be substantially completely rendered glassless and exhibited a metallic gloss.
  • a uniform glass film was formed as with Example 4.
  • all the materials subjected according to the present invention had a good iron loss value, and a particularly good iron loss value was obtained when the coverage of the insulating film was 3 to 4.5 ⁇ m.
  • the attained iron loss values were inferior to those in the materials according to the present invention.
  • grain oriented electrical steel sheets not having a glass film and having a very high magnetic flux density and an ultra low iron loss particularly grain oriented electrical steel sheets having a high magnetic flux density and a low iron loss and significantly excellent in the workability, such as slittability, cuttability and punchability, can be produced at a low cost.

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Claims (7)

  1. Verfahren zur Herstellung von kornorientiertem Elektrostahlblech mit hoher magnetischer Flussdichte und ausgezeichneten Eisenverlusteigenschaften durch Erhitzen einer Bramme auf eine niedrige Temperatur,
    wobei das Verfahren die Schritte umfasst:
    Erhitzen einer Bramme, umfassend in Gewichtsprozent 0,021 bis 0,075% C, 2,5 bis 4,5% Si, 0,010 bis 0,040% säurelösliches Al, 0,0030 bis 0,0130% N, gegebenenfalls 0,03 bis 0,15% P, 0,0140% oder weniger S und 0,05 bis 0,45% Mn, wobei der Rest aus Fe und unvermeidbaren Verunreinigungen besteht, auf eine Temperatur unterhalb von 1.280 °C, Warmwalzen der erhitzten Bramme und gegebenenfalls Glühen des warmgewalzten Blechs, ein- oder zweimaliges oder öfteres Kaltwalzen des Stahlblechs, wobei zwischen den Kaltwalzungen geglüht wird, um ein Stahlblech mit einer Enddicke bereitzustellen, Decarbonisierungsglühen des kaltgewalzten Blechs, Nitrieren des Stahlblechs, Beschichten des nitrierten Stahlblechs mit einem Glühseparator, Endkistenglühen des beschichteten Stahlblechs und Beschichten des geglühten Stahlblechs mit einem Isolierfilm, wobei der Glühseparator wenigstens eine Cl-Verbindung in einer Menge von 1 Gewichtsteil oder mehr, ausgedrückt als Cl, bezogen auf 100 Gewichtsteile MgO umfasst, und das Erhitzen beim Endkistenglühen in einer Atmosphäre, umfassend N2 und H2 mit einem Stickstoffgehalt von 30% oder mehr, mit einer Aufheizgeschwindigkeit von 20 °C/h oder weniger erfolgt.
  2. Verfahren zur Herstellung von kornorientiertem Elektrostahlblech mit hoher magnetischer Flussdichte und ausgezeichneten Eisenverlusteigenschaften nach Anspruch 1, wobei der Glühseparator als Zusatzstoff wenigstens einen Vertreter, ausgewählt aus Cl-Verbindungen, S-Verbindungen, Carbonaten, Nitraten und Sulfaten, in einer Menge von 1 bis 15 Gewichtsteilen enthält, bezogen auf die Gesamtmenge an Cl, S, (CO3)2- und (SO4)2-.
  3. Verfahren zur Herstellung von kornorientiertem Elektrostahlblech mit hoher magnetischer Flussdichte und ausgezeichneten Eisenverlusteigenschaften nach Anspruch 1, wobei die Menge an Sauerstoff, die dem Stahlblech beim Decarbonisierungsglühen zugegeben wird, 900 ppm oder weniger beträgt und das Verhältnis von Fe-Oxiden zu SiO2 im Oxidfilm 0,20 oder weniger beträgt.
  4. Verfahren zur Herstellung von kornorientiertem Elektrostahlblech mit hoher magnetischer Flussdichte und ausgezeichneten Eisenverlusteigenschaften nach Anspruch 1, wobei die Menge an Stickstoff, die dem Stahlblech beim Nitrierverfahren zugegeben wird, 150 ppm oder mehr beträgt.
  5. Verfahren zur Herstellung von kornorientiertem Elektrostahlblech mit hoher magnetischer Flussdichte und ausgezeichneten Eisenverlusteigenschaften nach Anspruch 1 oder 2, wobei der Glühseparator 100 Gewichtsteile MgO und, dazu zugegeben, 2 bis 30 Gewichtsteile wenigstens eines Vertreters, ausgewählt aus Carbonaten, Nitraten, Sulfaten und Sulfiden von Li, K, Bi, Na, Ba, Ca, Mg, Zn, Fe, Zr, Sn, Sr, Al usw., umfasst, wobei das im Glühseparator eingesetzte MgO eine solche Teilchengröße aufweist, dass 30% oder mehr des MgO aus Teilchen mit einem Durchmesser von 10 µm oder weniger, einer Zitronensäureaktivität (CAA-Wert) von 50 bis 300 s (gemessen bei 30 °C) und einem Hydratations-ig-Verlust von 5% oder weniger bestehen.
  6. Verfahren zur Herstellung von kornorientiertem Elektrostahlblech mit hoher magnetischer Flussdichte und ausgezeichneten Eisenverlusteigenschaften nach Anspruch 1, wobei bei der Beschichtung des Stahlblechs mit dem Isolierfilm ein- oder zweimal oder öfter ein Einbrennen durchgeführt wird, so dass die Filmdicke nach dem Einbrennen im Bereich von 2 bis 6 µm liegt.
  7. Verfahren zur Herstellung von kornorientiertem Elektrostahlblech mit hoher magnetischer Flussdichte und ausgezeichneten Eisenverlusteigenschaften nach Anspruch 1, wobei eine Furche oder gepunktete Vertiefung oder Verspannung unter einem Winkel von 45 bis 90° zur Walzrichtung des Stahlblechs mit Abständen von 2 bis 15 mm, einer Vertiefungstiefe von 1 bis 25 µm und einer Vertiefungsbreite von 500 µm oder weniger mittels einer Presse, einer Zahnwalze, Anreißen, Laserstrahl, lokalem Ätzen usw. nach wenigstens einem Schritt des Kaltwalzens, Decarbonisierungsglühens, Schlussglühens und der Isolierfilmbehandlung aufgebracht wird, um die Aufteilung der magnetischen Domänen zu bewirken.
EP93110517A 1992-07-02 1993-07-01 Kornorientiertes Elektroblech mit hoher Flussdichte und geringen Eisenverlusten und Herstellungsverfahren Expired - Lifetime EP0577124B1 (de)

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JP17579092 1992-07-02
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JP4175790A JP2691828B2 (ja) 1992-07-02 1992-07-02 磁束密度の極めて高い超低鉄損方向性電磁鋼板の製造方法。
JP20679592 1992-08-03
JP206795/92 1992-08-03
JP4206795A JPH0649654A (ja) 1992-08-03 1992-08-03 磁区制御後磁性の優れた珪素鋼板及びその製造方法
JP4220500A JP2671084B2 (ja) 1992-08-19 1992-08-19 鉄損特性の優れる高磁束密度方向性電磁鋼板及びその製造方法
JP220500/92 1992-08-19
JP22050092 1992-08-19
JP28478792 1992-10-22
JP284787/92 1992-10-22
JP4284787A JPH06136552A (ja) 1992-10-22 1992-10-22 磁気鉄損の優れた方向性電磁鋼板およびその製造法
JP30272892 1992-11-12
JP30272892A JP2671088B2 (ja) 1992-11-12 1992-11-12 磁気特性が優れ、鉄心加工性が著しく優れた高磁束密度方向性電磁鋼板及びその製造法
JP302728/92 1992-11-12
JP4340746A JPH06188116A (ja) 1992-12-21 1992-12-21 極めて鉄損の優れた高磁束密度方向性珪素鋼板およびその製造法
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013056496A1 (zh) * 2011-10-17 2013-04-25 宝山钢铁股份有限公司 电工钢表面极厚绝缘涂层的生产方法
US20220372589A1 (en) * 2018-07-31 2022-11-24 Nippon Steel Corporation Grain oriented electrical steel sheet
US11851726B2 (en) 2018-07-31 2023-12-26 Nippon Steel Corporation Grain oriented electrical steel sheet
US11939641B2 (en) 2018-07-31 2024-03-26 Nippon Steel Corporation Grain oriented electrical steel sheet

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3475258B2 (ja) * 1994-05-23 2003-12-08 株式会社海水化学研究所 セラミック被膜形成剤およびその製造方法
JP3598590B2 (ja) * 1994-12-05 2004-12-08 Ｊｆｅスチール株式会社 磁束密度が高くかつ鉄損の低い一方向性電磁鋼板
KR101262516B1 (ko) * 2010-11-10 2013-05-08 주식회사 포스코 자기 특성이 우수한 선재, 강선 및 이들의 제조방법
PL2949767T3 (pl) 2012-11-26 2019-10-31 Nippon Steel & Sumitomo Metal Corp Blacha ze stali elektrotechnicznej o zorientowanym ziarnie i sposób wytwarzania tej blachy
KR101480498B1 (ko) 2012-12-28 2015-01-08 주식회사 포스코 방향성 전기강판 및 그 제조방법
CN105451902B (zh) 2013-07-24 2018-08-24 Posco公司 取向电工钢板及其制造方法
JP6191529B2 (ja) * 2014-03-31 2017-09-06 Ｊｆｅスチール株式会社 方向性電磁鋼板用の一次再結晶焼鈍板および方向性電磁鋼板の製造方法
EP3653752A4 (de) 2017-07-13 2021-05-12 Nippon Steel Corporation Orientiertes elektromagnetisches stahlblech und herstellungsverfahren für ein orientiertes elektromagnetisches stahlblech
DE102017220718A1 (de) * 2017-11-20 2019-05-23 Thyssenkrupp Ag Optimierung des Stickstofflevels während der Haubenglühung II
CN111656465B (zh) 2018-01-31 2022-12-27 杰富意钢铁株式会社 方向性电磁钢板、使用该方向性电磁钢板而成的变压器的卷绕铁芯和卷绕铁芯的制造方法
WO2020149329A1 (ja) * 2019-01-16 2020-07-23 日本製鉄株式会社 方向性電磁鋼板及びその製造方法
EP3715480A1 (de) * 2019-03-26 2020-09-30 Thyssenkrupp Electrical Steel Gmbh Für mittelfrequenzanwendungen geeignetes eisen-silikon-material
US20210395851A1 (en) * 2020-06-17 2021-12-23 Axalta Coating Systems Ip Co., Llc Coated grain oriented electrical steel plates, and methods of producing the same

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60131976A (ja) * 1983-12-19 1985-07-13 Kawasaki Steel Corp 鉄損特性に優れた一方向性けい素鋼板の製造方法
US4543134A (en) * 1984-01-09 1985-09-24 Nippon Steel Corporation Process for producing grain-oriented electrical steel sheet having both improved magnetic properties and properties of glass film

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3671337A (en) * 1969-02-21 1972-06-20 Nippon Steel Corp Process for producing grain oriented electromagnetic steel sheets having excellent magnetic characteristics
BE789262A (fr) * 1971-09-27 1973-01-15 Nippon Steel Corp Procede de formation d'un film isolant sur un feuillard d'acierau silicium oriente
JPS5432412B2 (de) * 1973-10-31 1979-10-15
US4032366A (en) * 1975-05-23 1977-06-28 Allegheny Ludlum Industries, Inc. Grain-oriented silicon steel and processing therefor
JPS5322113A (en) * 1976-08-13 1978-03-01 Kawasaki Steel Co Process for making single anisotropic silicon steel plates with metallic brightness and separating compounds for annealing used therefor
JPS54120215A (en) * 1978-03-10 1979-09-18 Nippon Steel Corp High temperature annealing method of electrical sheets
JPS5844152B2 (ja) * 1978-12-27 1983-10-01 川崎製鉄株式会社 下地被膜をほとんど有しない方向性珪素鋼板の製造方法
US4367100A (en) * 1979-10-15 1983-01-04 Allegheny Ludlum Steel Corporation Silicon steel and processing therefore
JPS5996278A (ja) * 1982-11-25 1984-06-02 Kawasaki Steel Corp 焼鈍分離剤
DE3875676T2 (de) * 1987-08-31 1993-03-18 Nippon Steel Corp Verfahren zur herstellung von kornorientierten stahlblechen mit metallglanz und ausgezeichneter stanzbarkeit.
EP0392534B1 (de) * 1989-04-14 1998-07-08 Nippon Steel Corporation Verfahren zur Herstellung von kornorientierten Elektrostahlblechen mit hervorragenden magnetischen Eigenschaften
JPH0774388B2 (ja) * 1989-09-28 1995-08-09 新日本製鐵株式会社 磁束密度の高い一方向性珪素鋼板の製造方法
JPH0756048B2 (ja) * 1990-11-30 1995-06-14 川崎製鉄株式会社 被膜特性と磁気特性に優れた薄型方向性けい素鋼板の製造方法
JP2710000B2 (ja) * 1991-07-10 1998-02-04 新日本製鐵株式会社 被膜特性と磁気特性に優れた一方向性珪素鋼板
DE69326792T2 (de) * 1992-04-07 2000-04-27 Nippon Steel Corp Kornorientiertes Siliziumstahlblech mit geringen Eisenverlusten und Herstellungsverfahren
KR960010811B1 (ko) * 1992-04-16 1996-08-09 신니뽄세이데스 가부시끼가이샤 자성이 우수한 입자배향 전기 강 시트의 제조방법

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60131976A (ja) * 1983-12-19 1985-07-13 Kawasaki Steel Corp 鉄損特性に優れた一方向性けい素鋼板の製造方法
US4543134A (en) * 1984-01-09 1985-09-24 Nippon Steel Corporation Process for producing grain-oriented electrical steel sheet having both improved magnetic properties and properties of glass film

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013056496A1 (zh) * 2011-10-17 2013-04-25 宝山钢铁股份有限公司 电工钢表面极厚绝缘涂层的生产方法
US20220372589A1 (en) * 2018-07-31 2022-11-24 Nippon Steel Corporation Grain oriented electrical steel sheet
US11753691B2 (en) * 2018-07-31 2023-09-12 Nippon Steel Corporation Grain oriented electrical steel sheet
US11851726B2 (en) 2018-07-31 2023-12-26 Nippon Steel Corporation Grain oriented electrical steel sheet
US11939641B2 (en) 2018-07-31 2024-03-26 Nippon Steel Corporation Grain oriented electrical steel sheet

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EP0577124A3 (en) 1994-09-21
KR940005812A (ko) 1994-03-22
DE69332394T2 (de) 2003-06-12
KR960009170B1 (en) 1996-07-16
EP0577124A2 (de) 1994-01-05
DE69332394D1 (de) 2002-11-21

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