EP0588342A1 - Kornorientierte Elektrobleche und Material mit sehr hoher magnetischer Flussdichte und Verfahren zur Herstellung dieser - Google Patents

Kornorientierte Elektrobleche und Material mit sehr hoher magnetischer Flussdichte und Verfahren zur Herstellung dieser Download PDF

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EP0588342A1
EP0588342A1 EP93114924A EP93114924A EP0588342A1 EP 0588342 A1 EP0588342 A1 EP 0588342A1 EP 93114924 A EP93114924 A EP 93114924A EP 93114924 A EP93114924 A EP 93114924A EP 0588342 A1 EP0588342 A1 EP 0588342A1
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percent
flux density
magnetic flux
steel sheet
oriented electrical
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French (fr)
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EP0588342B1 (de
Inventor
Kunihide c/o Nippon Steel Corporation Takashima
Ryutarou c/o Nippon Steel Corporation Kawamata
Yoshio c/o NIPPON STEEL CORPORATION Nakamura
Isao c/o Nippon Steel Corporation Iwanaga
Norito C/O Nippon Steel Corporation Abe
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Nippon Steel Corp
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Nippon Steel Corp
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Priority claimed from JP04248194A external-priority patent/JP3098628B2/ja
Priority claimed from JP28648692A external-priority patent/JP3324044B2/ja
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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
    • H01F1/147—Alloys characterised by their composition
    • H01F1/14766—Fe-Si based alloys
    • H01F1/14775—Fe-Si based alloys in the form of sheets
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • 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
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • 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
    • C21D8/1216—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
    • 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
    • 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
    • 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

  • This invention relates to grain-oriented electrical steel sheet and material having very high magnetic flux density for use in the cores of transformers and the like in which ⁇ 110 ⁇ [001] Goss texture orientation is promoted to a high level, and a method of manufacturing same.
  • grain-oriented electrical steel sheet is used primarily for the core material of transformers and other electrical devices, and with respect to magnetic properties therefore has to have good excitation and core loss characteristics.
  • a B8 (magnetic flux density at a magnetic field strength of 800 A/m) value is used to express excitation characteristics numerically and core loss characteristics are expressed as a W 17/50 (core loss per kilogram of material that has been magnetized to 1.7 tesla at 50 Hz) value.
  • Core loss consists of hysteresis loss and eddy current loss.
  • Hysteresis loss depends on such factors as crystal orientation of the steel sheet (in other words, magnetic flux density), purity and internal stress, while factors such as electrical resistance, sheet thickness, grain size, magnetic domain size and steel sheet coating tension contribute to the eddy current loss.
  • JP-B-51-12451 and JP-B-53-28375 describe methods for improving the core loss characteristics that a tension coating imparts to steel sheet, but the tensioning effect of these depends on the product orientation, which is to say, the magnetic flux density, and as described in pages 2981 to 2984 of the Journal of Applied Physics, Vol. 41 No. 7 (June 1970), the higher the magnetic flux density B8 the greater the tensioning effect becomes.
  • the higher the magnetic flux density B8 the greater the tensioning effect becomes.
  • this method stably provided a product with a very high magnetic flux density B8 that far exceeded 1.92 tesla.
  • the object of the present invention is to provide a grain-oriented electrical steel sheet and material having very high magnetic flux density and a method of manufacturing same, in place of the above described core loss reduction means.
  • the present inventors succeeded in stably obtaining a product having a very high magnetic flux density higher than the conventional 1.92 tesla, and upon analyzing the product discovered the first commercial means for obtaining very high magnetic flux density within the limits of the secondary recrystallization grain shape and the slope between ideal Goss orientation.
  • Figure 1 shows the relationship between core loss W 17/50 and magnetic flux density B8 in 0.30-mm-thick grain-oriented electrical steel sheet containing 3 percent silicon that has been subjected to magnetic domain control by laser irradiation
  • Figure 2 shows the relationship between magnetic flux density and grain diameter in the cold rolling direction in 0.30-mm-thick grain-oriented electrical steel sheet containing 3.25 percent silicon
  • Figure 3 shows the relationship between magnetic flux density and grain diameter in the direction perpendicular to the cold rolling direction in 0.30-mm-thick grain-oriented electrical steel sheet containing 3.25 percent silicon
  • Figure 4 shows, by content ratio of fine secondary recrystallization grains, the relationship between core loss W 17/50 and magnetic flux density B8 in 0.30-mm-thick grain-oriented electrical steel sheet containing 3 percent silicon.
  • the inventors carried out various studies on the conditions needed to provide a product with very high magnetic flux density, and by controlling the secondary recrystallization matrix grains and the fine secondary recrystallization grains in the secondary recrystallization matrix grains in grain-oriented electrical steel sheet containing 2.5 to 4.0 percent silicon, succeeded in developing grain-oriented electrical steel sheet having very high magnetic flux density and excellent core loss reduction effect.
  • Figure 1 shows the relationship between core loss and magnetic flux density B8 in 3 percent silicon grain-oriented electrical steel sheet 0.30 mm thick from which the surface glass film has been removed by pickling, on which the measurement has been performed at a tension of 1.5 kg/mm2 after laser beam irradiation at a 5 mm pitch perpendicular to the direction of cold rolling.
  • the magnetic flux density B8 has been limited to not lower than 1.92 tesla.
  • Figure 2 shows the relationship between grain diameter in the direction of the cold rolling and magnetic flux density.
  • a magnetic flux density of 1.92 tesla or above is obtained stably in the case of grain diameters of not less than 10 mm in the secondary recrystallization grain matrix, and the attainment of 1.95 tesla is limited to grain diameters of not less than 10 mm.
  • secondary recrystallization grains less than 10 mm in diameter in the direction of the cold rolling and less than 5 mm in the direction perpendicular to the direction of cold rolling have a low magnetic flux density, and a ratio thereof that exceeds 20 percent will affect the magnetic flux density of the overall product and make it impossible to obtain a product having a magnetic flux density of 1.92 tesla or above, or a very high magnetic flux density of 1.95 tesla or above.
  • Figure 4 shows the relationship between core loss and magnetic flux density in grain-oriented electrical steel sheet product (with a tension coating) 0.30 mm thick containing 3 percent silicon.
  • a rough correspondence can be seen between magnetic flux density and core loss, but unlike in the case of the laser-beam irradiated material of Figure 1, there is considerable variation in core loss values for the same magnetic flux density.
  • the best core loss values were on a par with those of materials subjected to laser beam irradiation.
  • the matrix secondary recrystallization grains include not fewer than 50 percent fine secondary recrystallization grains having a diameter not exceeding 5 mm, a product was obtained which at a flux density of 1.92 tesla or above had a W 17/50 core loss of less than 1.0 W/kg, or at a flux density of 1.95 tesla or above had a W 17/50 core loss of 0.95 W/kg.
  • the inventors measured the fine orientation distribution features of the very high magnetic flux density grain-oriented electrical steel sheet according to the invention and, as a result, obtained the following new knowledge. Specifically, they learned that for a very high magnetic flux density grain-oriented electrical steel sheet to exhibit a flux density B8 of not less than 1.92 tesla, even of 1.95 tesla or higher, it is necessary that among the matrix secondary recrystallization grains not fewer than 90 percent be accounted for by grains whose ⁇ 110 ⁇ [001] axes are inclined relative to the rolled surface less than 10 degrees around either the TD axis or the ND axis, and that not fewer than 90 percent be accounted for by fine secondary recrystallization grains whose ⁇ 100 ⁇ [001] axes are inclined relative to the rolled surface less than 10 degrees around either the TD axis or the ND axis. Outside these ranges it is difficult to achieve the object of the invention, namely, to obtain a very high magnetic flux density grain-oriented electrical steel sheet exhibiting a flux density B8 of
  • the limitation of the grain diameter in the direction perpendicular to the cold rolling direction to not more than 50 mm is not required from the point of the magnetic properties and was set only because larger grains are seldom obtained in actual products.
  • the grain diameter in the cold rolling direction has a bearing on the aforesaid orientation distribution. If the secondary recrystallization annealing is conducted in the flat state with respect to cut sheet segments, the limitation to not more than 100 mm set by the invention is not required as far as the relationship with grain orientation is concerned. In actual industrial production, however, the secondary recrystallization annealing is ordinarily conducted with respect to coiled sheet.
  • the invention limits the length of the secondary recrystallization grains in the cold rolling direction to not more than 100 mm.
  • the very high magnetic flux density grain-oriented electrical steel sheet is produced from the same materials as used in the production of an ordinary high flux density grain-oriented electrical steel sheet using AlN as the main inhibitor, except that it further contains 0.0005 to 0.05 percent bismuth by weight.
  • a high magnetic flux density grain-oriented electrical steel sheet using AlN as its main inhibitor is typically produced by a high temperature slab heating method in which the slab is heated to a high temperature of not lower than 1280°C at the time of hot rolling (as in the method of JP-B-46-23820) or by a low temperature slab heating method in which the slab is heated to a temperature that does not exceed 1270°C (as in the method of JP-A-59-56522). Either of these methods can be used for obtaining a very high magnetic flux density grain-oriented electrical steel sheet by addition of a small amount of bismuth in accordance with this invention.
  • the improvement in flux density is slight, while at a content of more than 0.05 percent the effect of increasing flux density saturates, making addition of more than this amount uneconomical. Since a higher bismuth content also causes edge cracking during hot rolling, its upper limit is set at 0.05 percent. From the viewpoint of flux density improvement effect and negative economic effect (the cost increase and reduced yield from edge cracking resulting from bismuth addition), it is preferable for the bismuth content to be 0.0005 to 0.01 percent.
  • JP-A-50-72817, JP-A-51-78733 and JP-A-53-39922 Addition of bismuth during production of a grain-oriented electrical steel sheet material is taught by JP-A-50-72817, JP-A-51-78733 and JP-A-53-39922.
  • these patents describe grain-oriented electrical steel sheets that fundamentally do not contain aluminum and in their specifications explain that bismuth is added in lieu of Sb, an intergranular segregation element. Therefore, differently from in the present invention, bismuth has to be added at not less than 0.01 to 0.02 percent.
  • JP-A-51-107499 and JP-A-63-100127 also teach bismuth addition.
  • a carbon content of less than 0.03 percent is undesirable because it leads to abnormal grain growth during slab heating prior to hot rolling and results in a type of defective secondary recrystallization known as streaks.
  • a carbon content of less than 0.03 percent is undesirable because secondary recrystallization becomes unstable, and when it does occur, results in very poor magnetic flux density.
  • a carbon content of more than 0.15 percent is undesirable from the industrial viewpoint because the decarburization becomes insufficient at a normal decarburization annealing time period, thus giving rise to magnetic aging in the product.
  • Si A silicon content of less than 2.5 percent is undesirable because it increases the product eddy current loss, while a silicon content of greater than 4.0 percent is undesirable because it makes cold rolling difficult at normal temperature.
  • Mn In the high-temperature slab heating method, an manganese content of 0.02 to 0.30 percent is necessary for precipitating MnS as an auxiliary inhibitor to AlN. A content below the lower limit is undesirable because the amount of inhibitor becomes insufficient. A content above the upper limit is undesirable because MnS remains undissolved during slab heating and forms coarse precipitates after hot rolling, which weakens the inhibitor effect and causes unstable secondary recrystallization. In the low-temperature slab heating method, a manganese content of 0.10 to 0.80 percent is necessary for obtaining a high magnetic flux density.
  • Acid soluble aluminum serves as a main inhibitor forming element in the production of a high magnetic flux density grain-oriented electrical steel sheet. In this point, it is also an important constituent in the present invention. An acid soluble aluminum content of less than 0.010 percent is undesirable because the amount of precipitated AlN becomes insufficient and lowers the inhibitor strength. On the other hand, at a content of more than 0.065 percent the AlN precipitates become coarse, and this also lowers the inhibitor strength.
  • N Like acid soluble aluminum, nitrogen is a main inhibitor forming element. A content outside the range of 0.0030 to 0.0150 percent disrupts the optimum inhibitor state and, as such, is undesirable.
  • Tin is an element effective for stabilizing the secondary recrystallization of thin products. It is therefore required to be present at a content of not less than 0.05 percent. Its upper limit is set at 0.05 percent because its effect saturates above this level and addition of a greater amount only increases cost.
  • Cu Copper is an element effective for improving the glass film produced by added tin. A content of less than 0.01 percent produces little effect, while a content in excess of 0.10 percent lowers the magnetic flux density of the product.
  • One feature of the present invention is the requirement that, in terms of bismuth, the bismuth addition to the molten steel be made at 100 to 5000 g per ton of molten steel.
  • the source of the bismuth is not particularly limited and may be either metallic bismuth or a substance containing bismuth.
  • the molten steel whose composition has been adjusted in the foregoing manner is cast in the ordinary manner.
  • the casting method is not particularly specified.
  • the cast steel is then hot rolled into a hot-rolled coil.
  • the slab heating temperature at the time of hot rolling preferably not less than 1280°C in the case of the high-temperature slab heating production method and not more than 1270°C in the case of the low-temperature slab heating method.
  • the hot-rolled sheet is then subjected to a single stage cold rolling or several stages of cold rolling with interpass annealing to obtain a sheet of final thickness. Since the object is to obtain a high magnetic flux density grain-oriented electrical steel sheet, the final cold rolling reduction ratio (in the case of a single stage cold rolling, the reduction rate therefore) is preferably 65 to 95 percent.
  • the inhibitor strengthening effect obtained by addition of bismuth as explained earlier maintains the inhibitor effect up to high temperatures, making it possible to selectively grow Goss nuclei at the stage where the intergranular movement accelerates in the high-temperature region. This is thought to enable secondary recrystallization to proceed.
  • the cold rolling with interpass aging described in JP-B-54-13846 is generally conducted at the time of cold rolling, with the composition of the present invention a product with excellent magnetic flux density can be obtained using the tandem cold rolling method without conducting interpass aging treatment. There is therefore no need to rely on this prior art.
  • the sheet Prior to final cold rolling, the sheet is subjected to the high-temperature annealing JP-B-46-23820 and then quenched.
  • the composition of the present invention makes it possible to extend the range of the high-temperature annealing conditions.
  • One condition that can be broadened is the annealing temperature.
  • High-temperature annealing is ordinarily conducted at a temperature of 950 to 1200°C, preferably 1050 to 1200°C, and more preferably not less than 1100°C. With the composition of the present invention, however, it is possible to obtain a product with excellent magnetic flux density even when annealing is conducted within the temperature range of 850 to 1100°C.
  • JP-B-46-23820 calls for conducting the quenching following high-temperature annealing at a cooling rate which lowers the temperature from 950°C to 400°C in 2 to 200 seconds. According to Figure 4 of this prior art reference, higher cooling rates are preferable for obtaining a product with high magnetic flux density.
  • this reference states that for obtaining a magnetic flux density of 1.92 tesla using an annealing temperature of 1150°C it is necessary for the cooling from 950°C to 400°C to be conducted in less than 20 seconds.
  • the cooling condition can be extended toward the gradual cooling side. Specifically, a product exhibiting excellent magnetic flux density can be obtained even with gradual cooling in which the temperature is lowered from 950°C to 400°C in 30 seconds or more.
  • milder cooling conditions make it easier to achieve uniform cooling and to mitigate sheet brittleness by softening the quenched structure. This relaxation of cooling conditions therefore has high industrial significance and can be expected to be vigorously pursued in conjunction with the improvement of core loss property through increased silicon content.
  • the sheet cold rolled to final product thickness is annealed and then subjected to decarburization annealing in the usual manner.
  • the decarburization annealing method is not particularly specified, it is preferably conducted for 30 seconds to 30 minutes at 700 to 900°C in a mixed gas atmosphere consisting of wet hydrogen or hydrogen and nitrogen.
  • the surface of the decarburization annealed sheet is coated with an annealing separator of ordinary composition in the ordinary manner.
  • the secondary recrystallization annealing is conducted for not less than 5 hours at a temperature of not less 1000°C in an atmosphere of hydrogen or nitrogen or a mixture of both.
  • the sheet After excess annealing separator has been removed, the sheet is subjected to continuous annealing to flatten a coil set. An insulating coating is applied and baked on at the same time. If necessary, magnetic domain fining treatment is conducted by irradiation with a laser beam or the like. The invention does not particularly specify the magnetic domain fining treatment method.
  • An electrical steel sheet slab comprising 0.06 to 0.09 percent carbon, 3.0 to 3.35 percent silicon, 0.08 percent manganese, 0.025 percent sulfur, 0.020 to 0.035 percent acid soluble aluminum, 0.008 percent nitrogen, 0 to 0.15 percent tin, 0 to 0.05 percent copper and 0.0005 to 0.05 percent bismuth and the balance of iron and unavoidable impurities, was heated to 1320°C and hot rolled to a sheet thickness of 2.3 mm. The hot rolled sheets were then cold rolled to obtain product sheets 0.30 mm and 0.23 mm thick, and between cold rollings some of these sheets were subjected to aging treatment 5 times at 200°C. Prior to final cold rolling high temperature annealing was applied at 1120°C for 2 minutes.
  • the sheets were then subjected to decarburization annealing at 850°C, coated with an annealing separator in which the main constituent was MgO and then subjected to secondary recrystallization annealing at 1200°C. After removing the remaining annealing separator, pieces measuring 60 mm by 300 mm were cut as specimens to measure magnetic properties, and the specimens were annealed at 850°C to remove internal stresses. Next, an insulating coating was applied to the specimens and baked. The magnetic properties of some of the specimens were measured after the specimens were subjected to laser beam irradiation at 5 mm intervals. After then being pickled with strong acid, specimen grain diameter and the like were measured. The results are listed in Table 1.
  • Specimens 2 and 3 containing bismuth have a magnetic flux density exceeding 1.95 tesla and a ratio of large grains in the secondary recrystallization grain matrix exceeding 80 percent, and a core loss, following laser-beam irradiation, that is far lower than 0.90 W/kg, which for an 0.30 mm thick product can be described as excellent characteristics that surpass the limits of prior art products.
  • Specimens 4 and 5 containing bismuth have a magnetic flux density exceeding 1.95 tesla, a ratio of large grains in the secondary recrystallization grain matrix exceeding 80 percent, and the matrix large grains also include are more than 50 percent fine secondary recrystallization grains, so that even without laser-beam treatment they exhibit core loss values not exceeding 0.95 W/kg, which can be described as particularly excellent characteristics for an 0.30 mm thick product.
  • Specimens 9, 10 and 11 are 0.23 mm thick products and like 0.30 mm thick products are within the scope of the present invention, and as laser-beam irradiated products exhibit particularly good characteristics.
  • Specimens were prepared from 0.30 mm thick sheet produced by the same as Example 1, and the magnetic properties of the specimens were measured. Next, after pickling with strong acid, in each specimen the orientation of 20 crystal grains was measured, using the Laue method. The results are listed in Table 2.
  • Example 4 The products obtained in Example 4 were subjected to magnetic domain fining treatment using laser-beam irradiation at a pitch of 5 mm. The results are listed in Table 5. TABLE 5 Bi content (%) Cu content (%) B8 (T) W 17/50 (W/kg) 0.009 None added 2.000 0.62 0.009 0.07 2.013 0.60
  • the specimens of this Example have a very high magnetic flux density and after grain fining attain an excellent core loss of 0.6 W/kg.
  • 0.008 percent bismuth was added to steel containing 0.06 percent carbon, 3.2 percent silicon, 0.13 percent manganese, 0.007 percent sulfur, 0.028 percent acid soluble aluminum, 0.008 percent nitrogen and 0 to 0.12 percent tin.
  • the slab was heated to 1150°C and hot rolled to a sheet thickness of 1.8 mm.
  • the hot rolled sheets were then annealed at 1100°C, and after being pickled were subjected to aging treatment 5 times at 180°C between cold rolling passes, whereby the sheets were cold rolled to a thickness of 0.23 mm, subjected to decarburization annealing at 830°C and then subjected to nitriding treatment for 30 seconds at 750°C in an atmosphere containing ammonium.
  • Table 10 shows the relationship between bismuth content, hot-rolled sheet annealing and cooling conditions, the number of bending repetitions the annealed sheets were subjected to and the magnetic flux density B8 of the product sheets.
  • TABLE 10 Bi content (%) Cooling conditions Cooling rate °C/s No. of bendings B8 (T) None added Quenched in 100°C water 30 8 1.919 Atmospheric cooling 4 >20 1.852 0.010 Quenched in 100°C water 30 2 1.968 Forced air-cooling 13 18 1.982 Atmospheric cooling 4 >20 1.961

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EP93114924A 1992-09-17 1993-09-16 Kornorientierte Elektrobleche und Material mit sehr hoher magnetischer Flussdichte und Verfahren zur Herstellung dieser Expired - Lifetime EP0588342B1 (de)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
JP248194/92 1992-09-17
JP04248194A JP3098628B2 (ja) 1992-09-17 1992-09-17 超高磁束密度一方向性電磁鋼板
JP24819492 1992-09-17
JP28648692A JP3324044B2 (ja) 1992-10-23 1992-10-23 超高磁束密度一方向性電磁鋼板の製造方法
JP28648692 1992-10-23
JP286486/92 1992-10-23

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EP0588342A1 true EP0588342A1 (de) 1994-03-23
EP0588342B1 EP0588342B1 (de) 2000-07-12

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KR (1) KR0183408B1 (de)
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Cited By (9)

* Cited by examiner, † Cited by third party
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EP0716151A1 (de) * 1994-12-05 1996-06-12 Kawasaki Steel Corporation Kornorientiertes Elektrostahlblech mit hoher magnetischer Flussdichte und geringen Eisenverlusten und Herstellungsverfahren
EP0775752A1 (de) * 1995-11-27 1997-05-28 Kawasaki Steel Corporation Kornorientiertes Elektrostahlblech und dessen Herstellungsverfahren
EP0892072A1 (de) * 1997-07-17 1999-01-20 Kawasaki Steel Corporation Kornorientiertes Elektrostahlblech mit ausgezeichneten magnetischen Eigenschaften und dessen Herstellungsverfahren
EP0959142A2 (de) * 1998-05-21 1999-11-24 Kawasaki Steel Corporation Kornorientiertes elektromagnetisches Stahlblech und dessen Herstellungsverfahren
DE20302583U1 (de) * 2003-01-18 2003-06-12 W E T Wasser En Technologie Gm Filtermembranrückspülung mit einem Druckbehälter
EP1411139A1 (de) * 2001-07-16 2004-04-21 Nippon Steel Corporation Unidirektionales elektroblech mit ultrahoher magnetischer flussdichte; hervorragendem verlust von hochmagnetischem eisen und hervorragenden beschichtungseigenschaften und herstellungsverfahren dafür
CN103834856A (zh) * 2012-11-26 2014-06-04 宝山钢铁股份有限公司 取向硅钢及其制造方法
EP3594373A4 (de) * 2017-05-12 2020-02-26 JFE Steel Corporation Orientiertes elektromagnetisches stahlblech sowie verfahren zur herstellung davon
US20220098697A1 (en) * 2019-01-31 2022-03-31 Jfe Steel Corporation Grain-oriented electrical steel sheet and iron core using same

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KR100538595B1 (ko) * 1997-07-17 2006-03-22 제이에프이 스틸 가부시키가이샤 자기특성이우수한방향성전자강판및그의제조방법
KR101351957B1 (ko) * 2011-11-22 2014-01-22 주식회사 포스코 자성이 우수한 방향성 전기강판 및 이의 제조방법

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US5702541A (en) * 1994-12-05 1997-12-30 Kawasaki Steel Corporation High magnetic density, low iron loss, grain oriented electromagnetic steel sheet and a method for making
US5800633A (en) * 1994-12-05 1998-09-01 Kawasaki Steel Corporation Method for making high magnetic density, low iron loss, grain oriented electromagnetic steel sheet
EP0716151A1 (de) * 1994-12-05 1996-06-12 Kawasaki Steel Corporation Kornorientiertes Elektrostahlblech mit hoher magnetischer Flussdichte und geringen Eisenverlusten und Herstellungsverfahren
EP0775752A1 (de) * 1995-11-27 1997-05-28 Kawasaki Steel Corporation Kornorientiertes Elektrostahlblech und dessen Herstellungsverfahren
US5853499A (en) * 1995-11-27 1998-12-29 Kawasaki Steel Corporation Grain-oriented electrical steel sheet and method of manufacturing the same
EP0892072A1 (de) * 1997-07-17 1999-01-20 Kawasaki Steel Corporation Kornorientiertes Elektrostahlblech mit ausgezeichneten magnetischen Eigenschaften und dessen Herstellungsverfahren
US6110298A (en) * 1997-07-17 2000-08-29 Kawasaki Steel Corporation Grain-oriented electrical steel sheet excellent in magnetic characteristics and production process for same
EP0959142A3 (de) * 1998-05-21 2003-09-17 Kawasaki Steel Corporation Kornorientiertes elektromagnetisches Stahlblech und dessen Herstellungsverfahren
EP0959142A2 (de) * 1998-05-21 1999-11-24 Kawasaki Steel Corporation Kornorientiertes elektromagnetisches Stahlblech und dessen Herstellungsverfahren
EP1411139A1 (de) * 2001-07-16 2004-04-21 Nippon Steel Corporation Unidirektionales elektroblech mit ultrahoher magnetischer flussdichte; hervorragendem verlust von hochmagnetischem eisen und hervorragenden beschichtungseigenschaften und herstellungsverfahren dafür
EP1411139A4 (de) * 2001-07-16 2005-11-09 Nippon Steel Corp Unidirektionales elektroblech mit ultrahoher magnetischer flussdichte; hervorragendem verlust von hochmagnetischem eisen und hervorragenden beschichtungseigenschaften und herstellungsverfahren dafür
US7399369B2 (en) 2001-07-16 2008-07-15 Nippon Steel Corporation Ultra-high magnetic flux density grain-oriented electrical steel sheet excellent in iron loss at a high magnetic flux density and film properties and method for producing the same
US7981223B2 (en) 2001-07-16 2011-07-19 Nippon Steel Corporation Ultra-high magnetic flux density grain-oriented electrical steel sheet excellent in iron loss at a high magnetic flux density and film properties and method for producing the same
DE20302583U1 (de) * 2003-01-18 2003-06-12 W E T Wasser En Technologie Gm Filtermembranrückspülung mit einem Druckbehälter
CN103834856A (zh) * 2012-11-26 2014-06-04 宝山钢铁股份有限公司 取向硅钢及其制造方法
CN103834856B (zh) * 2012-11-26 2016-06-29 宝山钢铁股份有限公司 取向硅钢及其制造方法
EP3594373A4 (de) * 2017-05-12 2020-02-26 JFE Steel Corporation Orientiertes elektromagnetisches stahlblech sowie verfahren zur herstellung davon
US11578377B2 (en) 2017-05-12 2023-02-14 Jfe Steel Corporation Grain-oriented electrical steel sheet and method for producing the same
US20220098697A1 (en) * 2019-01-31 2022-03-31 Jfe Steel Corporation Grain-oriented electrical steel sheet and iron core using same
US11959149B2 (en) * 2019-01-31 2024-04-16 Jfe Steel Corporation Grain-oriented electrical steel sheet and iron core using same

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KR0183408B1 (ko) 1999-04-01
DE69328998D1 (de) 2000-08-17
KR940007195A (ko) 1994-04-26

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