EP0390142A2 - Procédé de fabrication d'une tôle en acier électromagnétique à grain orienté ayant une haute densité de flux magnétique - Google Patents

Procédé de fabrication d'une tôle en acier électromagnétique à grain orienté ayant une haute densité de flux magnétique Download PDF

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EP0390142A2
EP0390142A2 EP90106018A EP90106018A EP0390142A2 EP 0390142 A2 EP0390142 A2 EP 0390142A2 EP 90106018 A EP90106018 A EP 90106018A EP 90106018 A EP90106018 A EP 90106018A EP 0390142 A2 EP0390142 A2 EP 0390142A2
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primary
recrystallization
annealing
final
hot
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EP90106018A
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German (de)
English (en)
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EP0390142B1 (fr
EP0390142A3 (fr
EP0390142B2 (fr
Inventor
Yoshiyuki C/O Nippon Steel Co. R & D Ushigami
Tadashi C/O Nippon Steel Co. R & D Nakayama
Nobuyuki C/O Nippon Steel Co. R & D Takahasi
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Nippon Steel Corp
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Nippon Steel Corp
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Priority claimed from JP1079991A external-priority patent/JPH0689404B2/ja
Priority claimed from JP1079992A external-priority patent/JPH0689405B2/ja
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
    • C21D8/1244—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the heat treatment(s) being of interest
    • C21D8/1255—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

Definitions

  • the present invention relates to a process for producing a grain-oriented electrical steel sheet used as a soft magnetic material for an iron or magnet core of electrical equipments.
  • a grain-oriented electrical steel sheet has a crystal grain orientation referred to as "Goss-­orientation", in which grains are ⁇ 110 ⁇ 001>-oriented in terms of the Miller index, and usually has a Si content of 4.5% or less and a sheet thickness of from 0.10 to 0.35 mm.
  • the steel sheet should have an excellent magnetic characteristic, particularly the magnetic flux density and the watt-loss characteristics and, to meet that requirement, it is important that the crystal grains are highly uniformly aligned in the Goss-orientation. This extremely high accumulation to the Goss-orientation is achieved by utilizing a catastrophic grain growth referred to as "secondary recrystallization".
  • the inhibitor suppresses the growth of the primary-recrystallized grains which are out of the Goss-orientation, and thereby, promotes the preferential growth of grains which are in the Goss-orientation.
  • Typical precipitates are MnS as proposed by M. F. Littman in Japanese Examined Patent Publication (Kokoku) No. 30-3651 or by J. E. May and D. Turnbull in Trans. Met. Soc. A.I.M.E. 212, 1958, p769-781, AlN as proposed by Taguchi and Sakakura in Japanese Examined Patent Publication (Kokoku) No. 40-15644, MnSe as proposed by Imanaka et al. in Japanese Examined Patent Publication (Kokoku) No. 51-13469, and (Al, Si)N as proposed by Komatsu et al in Japanese Examined Patent Publication (Kokoku) No. 62-45285.
  • the first type utilizes a two-step cold rolling using MnS disclosed by M. F. Littman in Japanese Examined Patent Publication (Kokoku) No. 30-3651
  • the second type utilizes a large reduction of 80% or more in the final cold rolling step using AlN and MnS disclosed by Taguchi and Sakakura in Japanese Examined Patent Publication (Kokoku) No. 40-15644
  • the third type utilizes a two-step cold rolling using MnS (or MnSe) and Sb disclosed by Imanaka et al. in Japanese Examined Patent Publication (Kokoku) No. 51-13469.
  • a steel slab is heated at a high temperature, such as 1260°C or higher in the first type process, 1350°C or higher in the second type process when the slab contains 3% Si as disclosed in Japanese Unexamined Patent Publication (Kokai) No. 48-51852 although the temperature varies with the silicon content, or 1230°C or higher in the third type process as disclosed in Japanese Unexamined Patent Publication (Kokai) No. 51-20716 including an example in which an extremely high temperature of 1320°C is adopted to obtain a particularly high flux density. Under such a high temperature of slab heating, coarse precipitates present in steel matrix are once dissolved in steel to form a solid solution and then a fine precipitation occurs during hot rolling and/or the subsequent heat treatment.
  • a high temperature such as 1260°C or higher in the first type process, 1350°C or higher in the second type process when the slab contains 3% Si as disclosed in Japanese Unexamined Patent Publication (Kokai) No. 48-51852 although the temperature varies with the silicon
  • Japanese Examined Patent Publication (Kokoku) No. 54-14568 proposed that chromium nitride, titanium nitride, vanadium nitride or the like is added to an annealing separator to ensure the nitrogen partial pressure in the atmosphere during final annealing in which the secondary recrystallization is effected and Japanese Examined Patent Publication (Kokoku) No. 53-50008 proposed that a sulfide such as Fe2S is added to ensure the sulfur partial pressure and suppress decomposition of the precipitates so that the secondary recrystallization is stabilized.
  • a sulfide such as Fe2S
  • the precipitation occurs under a non-equilibrium condition and is strongly affected by the prior heat and strain history.
  • different portions of a steel slab have different heat and strain histories and a steel slab per se has a nonuniform crystal structure due to a macro-segregation of component elements over the slab thickness and to a local dispersion of the ⁇ - and the ⁇ -phases.
  • the object of the present invention is to provide a process for industrially stably producing a grain-­oriented electrical steel sheet having an excellent magnetic characteristic.
  • a process for producing a grain-oriented electrical steel sheet having a high magnetic flux density comprising the steps of: heating a steel slab comprising 1.8 to 4.8 wt% Si, 0.012 to 0.050 wt% acid-soluble Al, 0.010 wt% or less N, and the balance consisting of Fe and unavoidable impurities to a temperature for hot rolling; hot-rolling the heated slab to form a hot-­rolled strip; cold-rolling the hot-rolled strip to a final product sheet thickness under a final cold rolling reduction of 80% or more by a single step of cold rolling or by two or more steps of cold rolling with an intermediate annealing step inserted therebetween; primary-recrystallization-annealing the cold-rolled strip; final-annealing the primary-recrystallization-­annealed strip so that secondary-recrystallized grains substantially completely grow up in a temperature region of from 1000 to 1100°C and then purification is effected above
  • the present invention provides a process for stably producing a steel sheet product having a high flux density by defining the primary-recrystallized texture and the secondary recrystallization temperature.
  • the present inventors carried out a detailed study on the growth behavior of secondary-recrystallized grains and found the following novel point.
  • the cold-rolled strip was subjected to a primary recrystallization annealing, during which a decarburization treatment was also effected, followed by a nitriding treatment in an ammonia atmosphere to increase the nitrogen content of the steel strip by 0.005% or 0.018%.
  • MgO was applied on the samples from the steel strip, which samples were then heated to 900°C at a heating rate of 30°C/hr in an atmosphere of 10% N2 plus 90% H2 and rapidly heated to temperatures of from 950 to 1200°C and held there for 20 hours to effect an annealing so that secondary-­recrystallized grains fully grew up.
  • some samples were taken out of the heating furnace when they were heated to 900°C and an observation showed that the primary-recrystallized structure remained unchanged.
  • Figure 1 shows the relationship between the magnetic flux density (B8 value) and the secondary recrystallization temperature for the thus obtained sample products.
  • Figure 2 shows the flux density (B8 value) for the thus obtained sample products.
  • the optimum temperature range of from 1000 to 1100°C is considered to enable the preferential growth of grains having a sharp Goss-orientation when the primary-recrystallized texture has as a main orientation a ⁇ 111 ⁇ 112>-orientation established through a cold rolling reduction of 80% or higher.
  • a cold rolling reduction 80% or higher.
  • the basic fact is that grains having the Goss-­orientation grow preferentially in the specified temperature range of from 1000 to 1100°C in response to the primary-recrystallized texture established through the final cold rolling reduction of 80% or higher.
  • the secondary-recrystallized grains are allowed to grow in the specified temperature range, merely nitriding or increasing the partial nitrogen pressure of the atmosphere is sufficient to ensure a certain amount of inhibitors and to suppress the reduction rate of the inhibitor amount during the secondary recrystallization, so that the conventional problems due to nonuniform distribution of inhibitors is solved to enable the stable production of a grain-­oriented electrical steel sheet having a high flux density.
  • Japanese Unexamined Patent Publication (Kokai) No. 48-72025 disclosed a process in which the secondary recrystallization temperature is limited in the range of from 1000 to 1100°C, the primary-­recrystallized texture was not taken into consideration, and moreover, MnS used as an inhibitor is unstable in that temperature range as shown by W. M. Swift in Metallurgical Transaction, 4, 1973, p153-157 with the result that a low flux density of merely 1.8 Tesla was obtained.
  • a steel slab used in the present invention contains 1.8 to 4.8 wt% Si, 0.012 to 0.050 wt% acid-soluble Al, 0.010 wt% or less N, and the balance consisting of Fe and unavoidable impurities, but may contain elements other than those specified above.
  • Additive elements such as Mn, S, Se, B, Bi, Nb, Cr, Sn, and Ti may be used as inhibitor forming elements.
  • the slab heating temperature is not necessarily limited and need not be as high as that used in the conventional process because inhibitors can be formed in-situ in a later step of nitriding treatment.
  • the slab heating temperature should not preferably exceed 1300°C from the viewpoint of production cost.
  • the slab heating temperature is more specifically controlled in accordance with the Al and the N contents not to exceed a temperature above which AlN is completely dissolved in steel.
  • the slab heating temperature is not preferably lower than 1000°C because the deformation resistance of the slab increases with lowering of the heating temperature and the steel sheet shape becomes difficult to ensure.
  • oxidation of the slab surface excessively occurs to form a melt referred to as "scum".
  • the slab heating temperature is preferably in the range of from 1000 to 1270°C.
  • the primary-recrystallized grain size is determined by the condition of primary recrystallization annealing including the annealing temperature and duration time and is affected more essentially by the inhibitors which are present before the primary recrystallization annealing.
  • the primary recrystallization annealing must be carried out at a higher temperature and/or for a longer time duration to undesirably raise the production cost, in order to obtain a grain size comparable with that obtained by the present invention, for example, the average grain diameter (D) of about 15 ⁇ m or greater.
  • a higher temperature and/or a longer time may cause an abnormal grain growth during the primary recrystallization temperature, with the result that the secondary recrystallization becomes unstable.
  • the slab heating temperature can be determined from the Al and the N contents by using the above equation.
  • the hot-rolled strip is annealed, if necessary, at a temperature of from 750 to 1200°C for 30 sec to 30 min.
  • the hot-rolled strip is cold-rolled to a final product sheet thickness under a final cold rolling reduction of 80% or more by a single step of cold rolling or by two or more steps of cold rolling with an intermediate annealing therebetween.
  • the reduction of 80% or more is essential for obtaining a desired primary-recrystallized texture.
  • the strip which has been primary-recrystallization-annealed is subjected to a nitriding treatment before the secondary recrystallization in the final annealing step occurs and that the secondary-recrystallized grains are allowed to substantially completely grow in the temperature region of from 1000 to 1100°C.
  • the nitriding treatment may be carried out in any conventional way for nitriding, for example, nitriding using a gas atmosphere having a nitriding ability such as ammonia gas, nitriding during the final annealing by using an annealing separator containing a metal nitride additive having a nitriding ability such as manganese nitride, chromium nitride, or the like.
  • a gas atmosphere having a nitriding ability such as ammonia gas
  • nitriding during the final annealing by using an annealing separator containing a metal nitride additive having a nitriding ability such as manganese nitride, chromium nitride, or the like.
  • the nitriding carried out after the primary recrystallization annealing and before the beginning of the secondary recrystallization strengthens the previously formed weak inhibitor to stabilize the secondary recrystallization.
  • the final annealing of the primary-recrystallization-­annealed strip is carried out so that secondary-­recrystallized grains substantially grow in a temperature region T defined in the following expressions (1) and (2), as specified in claim 2: T ⁇ 20D + 700 (1) 1000 ⁇ T ⁇ 1100 (2) where "D” denotes the average grain diameter of primary-recrystallized grains, in ⁇ m.
  • Steel slabs comprising 3.2 to 3.3 wt% Si, 0.010 to 0.045 wt% acid-soluble Al, 0.0030 to 0.0090 wt% N, 0.020 to 0.090 wt% C, 0.070 to 0.500 wt% Mn, 0.0030 to 0.0300 wt% S, and the balance Fe and unavoidable impurities were heated to different temperatures of from 1150 to 1400°C and hot-rolled to form 2.3 mm thick hot-rolled strips, which were then annealed at different temperatures of from 900 to 1200°C and cold-rolled at a reduction of 88% to a final thickness of 0.285 mm.
  • the cold-rolled strips were primary-recrystallization-­annealed at temperatures of from 830 to 1000°C, during which a decarburization was also effected.
  • An annealing separator containing MgO as a main component was then applied on the strips.
  • Samples from the strips were heated to 900°C at a heating rate of 20°C/hour in an atmosphere of 10% N2 plus 90% H2 and then rapidly heated to predetermined different temperatures of from 950 to 1200°C and held there for 20 hours so that the secondary-recrystallized grains were allowed to fully grow. During this sequence, some samples were taken out of the heating furnace when they were heated to 900°C and an observation showed that the primary-recrystallized grain sizes remained unchanged.
  • Fig. 7 shows the relationship among the magnetic flux density (B8), the average grain diameter of primary-recrystallized grains, and the secondary recrystallization temperature for the above-obtained sample products.
  • the secondary recrystallization is a phenomenon in which the thermal change of primary-recrystallized structure and the thermal change of inhibitor are competing. Namely, as the inhibitor becomes weak during final annealing, the grains having orientations close to the Goss-orientation, which are present in a scattered condition, form a nucleus and begin to grow.
  • the growth rate V (cm/sec) of secondary-recrystallized grains is generally expressed by the following equation: V ⁇ exp(-Q/RT) ⁇ 1 D where Q is the activation energy for the grain growth and R is a gas constant.
  • the secondary recrystallization temperature is defined in accordance with the primary-recrystallized grain diameter (D).
  • the method of controlling the secondary recrystallization temperature i.e., the temperature at which the secondary-recrystallized grains are allowed to grow is not limited and may carried out by holding or slow heating in the corresponding temperature region.
  • a steel slab consisting of 3.3 wt% Si, 0.030 wt% acid-soluble Al, 0.008 wt% N, 0.05 wt% C, 0.14 wt% Mn, 0.007 wt% S and the balance Fe and unavoidable impurities was hot-rolled to form a 1.8 mm thick hot-­rolled strip.
  • the hot-rolled strip was annealed at 1100°C for 2 min and then cold-rolled at a reduction of 88% to a final product thickness of 0.20 mm.
  • the cold-rolled strip was subjected to a primary recrystallization annealing at 830°C, during which a decarburization was also effected.
  • Steel slabs comprising 3.28 wt% Si, 0.027 wt% acid-soluble Al, 0.0060 wt% N, 0.14 wt% Mn, 0.007 wt% S and the balance Fe and unavoidable impurities were heated to different temperatures of 1150 and 1300°C and hot-rolled to form 1.8 mm thick hot-rolled strips.
  • the strips were annealed by heating at 1150°C for 30 sec and subsequently holding at 900°C for 30 sec.
  • the strips were then cold-rolled at a reduction of 89% to a final sheet thickness of 0.20 mm.
  • the cold-rolled strips were primary-recrystallization-annealed at 850°C for 90 sec, during which a decarburization was also effected.
  • a steel slab comprising 3.3 wt% Si, 0.030 wt% acid-soluble Al, 0.003 wt% N, 0.048 wt% C, 0.13 wt% Mn, 0.010 wt% S, and the balance Fe and unavoidable impurities was heated to 1100°C and hot-rolled to a 2.0 mm thick hot-rolled strip.
  • the strip was annealed at 1000°C and cold-rolled at a reduction of 89% to a final thickness of 0.23 mm. Samples from the cold-­rolled strip were primary-recrystallization-annealed at different temperatures of 800, 850, and 900°C for 120 sec, during which a decarburization was also effected.
  • the samples were then subjected to a nitriding treatment in an atmosphere of ammonia gas so that the nitrogen content was increased by 0.02 to 0.03 wt%.
  • An annealing separator was applied on the nitrided samples, which were then final-annealed by heating to 1000°C at a heating rate of 25°C/hr in an atmosphere of 10% N2 plus 90% H2 , then heating to 1100°C at a heating rate of 5°C/hr, subsequently heating to 1200°C at a heating rate of 25°C/hr and holding there in a changed atmosphere of 100% H2 to effect purifica­tion.

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EP19900106018 1989-03-30 1990-03-29 Procédé de fabrication d'une tÔle en acier électromagnétique à grain orienté ayant une haute densité de flux magnétique Expired - Lifetime EP0390142B2 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP79991/89 1989-03-30
JP1079991A JPH0689404B2 (ja) 1989-03-30 1989-03-30 磁束密度の高い一方向性電磁鋼板の製造方法
JP1079992A JPH0689405B2 (ja) 1989-03-30 1989-03-30 磁束密度の高い一方向性電磁鋼板の製造方法
JP79992/89 1989-03-30

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EP0390142A2 true EP0390142A2 (fr) 1990-10-03
EP0390142A3 EP0390142A3 (fr) 1992-09-30
EP0390142B1 EP0390142B1 (fr) 1996-06-26
EP0390142B2 EP0390142B2 (fr) 1999-04-28

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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0526834A1 (fr) * 1991-07-29 1993-02-10 Nkk Corporation Procédé pour la fabrication de bandes d'acier au silicium ayant une granulation fine disposée en orientation de GOSS
EP0566986A1 (fr) * 1992-04-16 1993-10-27 Nippon Steel Corporation Procédé de production de tôles d'acier électrique à grains orientés et ayant des propriétés magnétiques excellentes
US5261972A (en) * 1991-10-28 1993-11-16 Nippon Steel Corporation Process for producing grain-oriented electrical steel strip having high magnetic flux density
US5266129A (en) * 1991-09-26 1993-11-30 Nippon Steel Corporation Process for production of oriented electrical steel sheet having excellent magnetic properties
EP0585956A1 (fr) * 1992-09-04 1994-03-09 Nippon Steel Corporation Tôle d'acier électrique épaisse à grains orientés ayant des propriétés magnétiques excellentes
EP0588342A1 (fr) * 1992-09-17 1994-03-23 Nippon Steel Corporation Tôle d'acier électrique à grains orientés et matériau à haute densité de flux magnétique et procédé pour leur fabrication
EP0600181A1 (fr) * 1992-11-12 1994-06-08 Armco Inc. Méthode pour la fabrication d'une tôle d'acier électrique à grains orientés réguliers par laminage à froid en une étape
DE4311151C1 (de) * 1993-04-05 1994-07-28 Thyssen Stahl Ag Verfahren zur Herstellung von kornorientierten Elektroblechen mit verbesserten Ummagnetisierungsverlusten
US5858126A (en) * 1992-09-17 1999-01-12 Nippon Steel Corporation Grain-oriented electrical steel sheet and material having very high magnetic flux density and method of manufacturing same
US6858095B2 (en) 1992-09-04 2005-02-22 Nippon Steel Corporation Thick grain-oriented electrical steel sheet exhibiting excellent magnetic properties
EP1179603A3 (fr) * 2000-08-08 2007-07-04 Nippon Steel Corporation Procédé de fabrication d'une tôle d'acier à grains orientés presentant une densité de flux magnétique élevée

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10311215B4 (de) * 2003-03-14 2005-09-15 Thyssenkrupp Electrical Steel Gmbh Verfahren zum Herstellen von kornorientiertem, kaltgewalztem Elektroblech oder -band

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2867559A (en) * 1956-12-31 1959-01-06 Gen Electric Method for producing grain oriented silicon steel
EP0098324A1 (fr) * 1982-07-08 1984-01-18 Nippon Steel Corporation Procédé de production d'un feuillard d'acier au silicium à grain orienté contenant de l'aluminium
JPS59215419A (ja) * 1983-05-20 1984-12-05 Nippon Steel Corp 磁束密度の高い一方向性珪素鋼板の製造方法
JPS62222024A (ja) * 1986-03-22 1987-09-30 Nippon Steel Corp 磁束密度の極めて高い一方向性電磁鋼板の製造方法
EP0307905A2 (fr) * 1987-09-18 1989-03-22 Nippon Steel Corporation Procédé pour la fabrication de tôles d'acier électrique à grains orientés et à densité de flux magnétique très élevée
EP0219611B1 (fr) * 1985-08-15 1990-05-16 Nippon Steel Corporation Procédé de fabrication d'une tôle en acier électrique à grain orienté

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2867559A (en) * 1956-12-31 1959-01-06 Gen Electric Method for producing grain oriented silicon steel
EP0098324A1 (fr) * 1982-07-08 1984-01-18 Nippon Steel Corporation Procédé de production d'un feuillard d'acier au silicium à grain orienté contenant de l'aluminium
JPS59215419A (ja) * 1983-05-20 1984-12-05 Nippon Steel Corp 磁束密度の高い一方向性珪素鋼板の製造方法
EP0219611B1 (fr) * 1985-08-15 1990-05-16 Nippon Steel Corporation Procédé de fabrication d'une tôle en acier électrique à grain orienté
JPS62222024A (ja) * 1986-03-22 1987-09-30 Nippon Steel Corp 磁束密度の極めて高い一方向性電磁鋼板の製造方法
EP0307905A2 (fr) * 1987-09-18 1989-03-22 Nippon Steel Corporation Procédé pour la fabrication de tôles d'acier électrique à grains orientés et à densité de flux magnétique très élevée

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 12, no. 84 (C-482)17 March 1988 & JP-A-62 222 024 ( NIPPON STEEL ) 30 September 1987 *
PATENT ABSTRACTS OF JAPAN vol. 9, no. 82 (C-275)(1805) 11 April 1985 & JP-A-59 215 419 ( SHIN NIPPON SEITETSU ) 5 December 1984 *

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0526834A1 (fr) * 1991-07-29 1993-02-10 Nkk Corporation Procédé pour la fabrication de bandes d'acier au silicium ayant une granulation fine disposée en orientation de GOSS
US5489342A (en) * 1991-07-29 1996-02-06 Nkk Corporation Method of manufacturing silicon steel sheet having grains precisely arranged in goss orientation
US5354389A (en) * 1991-07-29 1994-10-11 Nkk Corporation Method of manufacturing silicon steel sheet having grains precisely arranged in Goss orientation
US5266129A (en) * 1991-09-26 1993-11-30 Nippon Steel Corporation Process for production of oriented electrical steel sheet having excellent magnetic properties
US5261972A (en) * 1991-10-28 1993-11-16 Nippon Steel Corporation Process for producing grain-oriented electrical steel strip having high magnetic flux density
EP0566986A1 (fr) * 1992-04-16 1993-10-27 Nippon Steel Corporation Procédé de production de tôles d'acier électrique à grains orientés et ayant des propriétés magnétiques excellentes
US5512110A (en) * 1992-04-16 1996-04-30 Nippon Steel Corporation Process for production of grain oriented electrical steel sheet having excellent magnetic properties
EP0585956A1 (fr) * 1992-09-04 1994-03-09 Nippon Steel Corporation Tôle d'acier électrique épaisse à grains orientés ayant des propriétés magnétiques excellentes
US6858095B2 (en) 1992-09-04 2005-02-22 Nippon Steel Corporation Thick grain-oriented electrical steel sheet exhibiting excellent magnetic properties
EP0588342A1 (fr) * 1992-09-17 1994-03-23 Nippon Steel Corporation Tôle d'acier électrique à grains orientés et matériau à haute densité de flux magnétique et procédé pour leur fabrication
US5858126A (en) * 1992-09-17 1999-01-12 Nippon Steel Corporation Grain-oriented electrical steel sheet and material having very high magnetic flux density and method of manufacturing same
EP0600181A1 (fr) * 1992-11-12 1994-06-08 Armco Inc. Méthode pour la fabrication d'une tôle d'acier électrique à grains orientés réguliers par laminage à froid en une étape
DE4311151C1 (de) * 1993-04-05 1994-07-28 Thyssen Stahl Ag Verfahren zur Herstellung von kornorientierten Elektroblechen mit verbesserten Ummagnetisierungsverlusten
EP1179603A3 (fr) * 2000-08-08 2007-07-04 Nippon Steel Corporation Procédé de fabrication d'une tôle d'acier à grains orientés presentant une densité de flux magnétique élevée
EP2107130A1 (fr) * 2000-08-08 2009-10-07 Nippon Steel Corporation Procédé de production de tôle électrique magnétique à grains orientés dotée d'une densité de flux hautement magnétique

Also Published As

Publication number Publication date
EP0390142B1 (fr) 1996-06-26
DE69027553D1 (de) 1996-08-01
DE69027553T3 (de) 1999-11-11
EP0390142A3 (fr) 1992-09-30
EP0390142B2 (fr) 1999-04-28
DE69027553T2 (de) 1997-02-20

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