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EP0947597B2 - Procédé de fabrication d'une tôle d'acier à grains orientés presentant d'excellentes caracteristiques magnétiques - Google Patents

Procédé de fabrication d'une tôle d'acier à grains orientés presentant d'excellentes caracteristiques magnétiques Download PDF

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Publication number
EP0947597B2
EP0947597B2 EP99105071.7A EP99105071A EP0947597B2 EP 0947597 B2 EP0947597 B2 EP 0947597B2 EP 99105071 A EP99105071 A EP 99105071A EP 0947597 B2 EP0947597 B2 EP 0947597B2
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Prior art keywords
annealing
steel sheet
hot
grain
temperature
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German (de)
English (en)
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EP0947597B1 (fr
EP0947597A3 (fr
EP0947597A2 (fr
Inventor
Tomoji c/oNIPPON STEEL CORP. YAWATA WORKS Kumano
Norikazu c/oNIPPON STEEL CORP YAWATA WORK Fujii
Katsuro c/o NITTETSU PLANT DESIGNING CORP Kuroki
Koji c/oNIPPON STEEL CORP. YAWATA WORKS Yamasaki
Yoshifumi NIPPON STEEL CORP. YAWATA WORKS Ohata
Hisashi c/o NIPPON STEEL CORP. YAWATA WORKS Mogi
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Nippon Steel Corp
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Nippon Steel and Sumitomo Metal Corp
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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
    • 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
    • C21D3/00—Diffusion processes for extraction of non-metals; Furnaces therefor
    • C21D3/02—Extraction of non-metals
    • C21D3/04—Decarburising
    • 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
    • C21D8/1227—Warm 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
    • C21D8/1272—Final recrystallisation annealing

Definitions

  • This invention relates to a method of producing a grain-oriented electrical steel sheet excellent in magnetic characteristics for use primarily in the cores of electrical transformers and the like.
  • a generally known method used to produce a grain-oriented electrical steel sheet is to heat the slab to a very high temperature between 1350°C and a maximum of 1450°C and to hold (soak) the slab at this temperature for a period sufficient to ensure uniform heating throughout its entirety. This is for putting MnS, AlN and the like into solid solution so that they function as inhibitors. Since this method requires the slab to be heated to a very high temperature, however, it involves various problems in actual production. For example, (1) the slag produced by melting of the slab surface layer causes difficult problems from the point of heating furnace maintenance, (2) the desired hot-rolling temperature is difficult to secure, and (3) yield is reduced by large edge cracks occurring in hot-rolled strip.
  • the nitriding conditions become inconstant because of the variation in the composition of the oxide layer formed during decarburization and the resulting variation in the amount of nitrides formed may cause unstable secondary recrystallization.
  • the method according to JP-A-9-118964 which uses a large amount of Mn in order to improve the iron loss of the steel sheet by increasing its resistivity, is not suitable for industrial production because it is very liable to produce defects in the glass film.
  • These methods are characterized by not requiring an additional process such as the nitriding in the first category of methods.
  • Cu x S as an inhibitor for controlling secondary recrystallization and the method is not suitable for producing a high permeability grain-oriented electrical steel sheet having weak texture by applying a final cold rolling reduction ratio of greater than 80% ( Iron and Steel, p. 2049, No. 15, Vol. 70, No. 1984 ). Specifically, as shown in Fig.
  • Fig. 4 shows the relationship between the magnetic flux density (B 8 :T) and the iron loss (W 17/50 :W/kg) of a thickness of 0.30 mm product.
  • ⁇ represents the TGO of JP-A-6-322443 and the broken line indicates the results of inventor tests and shows the secondary recrystallization to be poor. ⁇ indicates Comparative Examples of the present invention.
  • JP-A-6-322443 calls for precipitation of at least 60% of the total N content in the hot-rolled strip state as AlN
  • the hot-rolled strip having the composition shown in the Examples (Mn, S, Al, N) and obtained at a slab heating temperature on the level of 1270°C uniform precipitation of AlN and MnS, which are precipitates whose solubility product is a quadratic function, is extremely difficult industrially. It is therefore impossible to obtain uniform magnetic characteristics throughout the coil length.
  • WO 98/41659 relates to a process for the inhibition control in the production of grain-oriented electrical sheets in which the hot-rolled strip inhibition is controlled through careful balancing of the copper, aluminium and carbonium contents to obtain optimum grain dimensions during the decarburization annealing and to allow a subsequent high-temperature continuous thermal treatment.
  • WO 98/08987 relates to a process for the production of grain oriented electrical steel strip having high magnetic characteristics, starting from thin slab in which the control of condition of thin real continuous casting allows to obtain advantageous solidification structure and precipitates and to decriticize the process for controlling the grain dimensions.
  • An object of this invention is to enable stable and simple production of a grain-oriented electrical steel sheet excellent in magnetic characteristics by compensating for the drawbacks of the technologies in both of the foregoing categories.
  • the most salient feature of this invention is that, in a method for producing a grain-oriented electrical steel sheet permitting a lower slab heating temperature than heretofore owing to avoidance of MnS as the main inhibitor for secondary recrystallization, it causes MnS (or MnSe), Cu x S (or CuSe) etc.
  • an object of the present invention is to metallurgically separate the functioning stages of inhibitors playing major roles in production of the grain-oriented electrical steel sheet and to cause each to fulfill its own function using different substances.
  • the temperature of the decarburization annealing during which primary recrystallization takes place is generally low, i.e., no higher than 930°C. At this stage, therefore, the strong inhibitor formed during high-temperature hot rolling in the conventional method is unnecessary. Since the present invention uses sulfides and/or selenides as the primary inhibitors, the temperature dependence of the primary recrystallization grains is very small and, therefore, the temperature of the primary recrystallization annealing (actually the decarburization annealing) need not be greatly modified. This ensures very high stability of the primary oxide layer composition and the amount of nitrides formed by the ensuing nitriding, remarkably reduces glass film defects, and also eliminates nonuniformity of secondary recrystallization to enable stable industrial production.
  • the secondary recrystallization requires an inhibitor made stable against high temperatures by addition of sulfides and/or selenides.
  • AlN formed by the nitriding mainly provides this stabilizing effect.
  • Al combines with N to form AlN, which functions mainly as a secondary inhibitor. Some AlN is formed before nitriding and some is formed during the high-temperature annealing after nitriding. An Al content of 0.0010 ⁇ 0.035% is needed to ensure the required amounts of AlN both before and after nitriding. When the Al content is outside this range, the primary recrystallization grain diameter becomes difficult to control and the secondary recrystallization therefore does not proceed stably.
  • the present invention uses mainly sulfides and selenides to control the primary recrystallization grains.
  • AlN contained in the slab is also necessary for primary recrystallization grain control, and control of the primary recrystallization grain diameter is difficult when the N content is below 0.0030%.
  • the upper limit of the N content is defined as 0.010% because at higher contents defects, i.e., blisters, occur on the steel sheet surface. Owing to this limitation, the amount of N contained in the slab is not sufficient to control the secondary recrystallization. This is why the nitriding explained later is necessary.
  • Cr has a beneficial effect on formation of a forsterite film (glass film).
  • the beneficial effects on formation of a forsterite film are slight.
  • Ni is highly effective for obtaining uniform dispersion of precipitates as primary and secondary inhibitors, its addition further improves and stabilizes the magnetic characteristics. It has no effect when added to less than 0.02%, while addition to over 0.3% makes formation of a forsterite film difficult because it impedes oxygen enrichment after decarburization annealing.
  • Mo and Cd also contribute to inhibitor strengthening by forming sulfides and selenides. They have no effect at a content under 0.008%, while when present at over 0.3%, they cause formation of enlarged precipitates that do not function as inhibitors that stabilize the magnetic characteristics.
  • the average diameter of the primary recrystallization grains after completion of decarburization annealing is specified as 18 ⁇ 35 ⁇ m in Japanese Patent Application 06-046161 , for example, in the present invention the average grain diameter of the primary recrystallization grains must be not less than 7 ⁇ m and less than 15 ⁇ m. This is an extremely important point of the invention as regards achieving excellent magnetic characteristics (particularly iron loss property).
  • One reason for this is that, from the viewpoint of grain growth, the volume fraction of Goss oriented grains that can grow as secondary recrystallization grains becomes greater at the primary recrystallization stage when the primary recrystallization grain diameter is smaller ( Materials Science Forum, Vol. 204 ⁇ 206, Part 2, p. 631 ).
  • the secondary recrystallization starts early at the temperature of heating stage (at a low-temperature point) of the final finish annealing.
  • the magnetic characteristics are highly stable.
  • the present invention requires that the steel sheet be nitrided between the completion of the decarburization annealing and the start of secondary recrystallization.
  • This can be achieved either by the method of mixing nitrides (CrN, MnN and the like) with the annealing separator used during high-temperature annealing or by the method of nitriding the decarburization-annealed sheet as a running strip in an atmosphere containing ammonia. While either method can be used, the latter exhibits better stability in industrial production.
  • the amount of nitridation is below 0.001%, the secondary recrystallization is unstable, and when it is over 0.020%, many defects exposing the matrix occur in the glass film.
  • the preferred range is 0.005 ⁇ 0.015%.
  • the slab heating temperature prior to hot rolling is an important factor in this invention. Ultra-high temperature slab heating to a temperature exceeding 1350°C encounters severe difficulties in industrial production. Below the lower limit of 1050°C, on the other hand, the hot rolling becomes practically difficult and, moreover, the generation of primary inhibitor, a key point of the present invention, falls to an insufficient level that causes the primary recrystallization grain diameter to vary greatly with the decarburization annealing temperature. From the viewpoint of ease of hot rolling and the shape (crown) of the hot-rolled strip, the preferred slab heating temperature range is 1200 ⁇ 1300°C.
  • the hot rolling temperature is, moreover, prescribed as: 850 + 2500 ⁇ S ⁇ e ⁇ q + 400 ⁇ M ⁇ N ⁇ F ⁇ O ⁇ T ⁇ starting ⁇ temperature o ⁇ f finishing ⁇ h ⁇ o ⁇ t - rolling ⁇ 1100 + 3000 ⁇ S ⁇ E ⁇ Q + 800 ⁇ M ⁇ n ⁇ 1350 ⁇ ° ⁇ C 800 + 2500 ⁇ S ⁇ e ⁇ q + 400 ⁇ M ⁇ N ⁇ F ⁇ T ⁇ finishing ⁇ temperature o ⁇ f finishing ⁇ h ⁇ o ⁇ t - rolling ⁇ 1050 + 3000 ⁇ S ⁇ E ⁇ Q + 800 ⁇ M ⁇ n ⁇ 1350 ⁇ ° ⁇ C
  • a slab is first produced by the conventional continuous casting method to have an initial thickness in the range of 150 mm to 300 mm, preferably 200 mm to 250 mm. It is also possible instead to use a so-called thin slab with an initial thickness in the range between about 30 mm and 70 mm. These ranges are advantageous in that no roughing rolling down to an intermediate thickness is needed at the time of producing the hot-rolled strip. If a slab or strip is produced beforehand by strip casting, moreover, a grain-oriented electrical steel sheet can be produced by the invention using a slab or strip having an even thinner initial thickness.
  • the heating method adopted for the hot rolling in industrial production is not limited to ordinary gas heating but can instead be induction heating or direct electric heating. No problem is encountered when the shape needed for these special heating methods is obtained by effecting breakdown on the cast slab. When the heating temperature is high, i.e., over 1300°C, this breakdown can be used to improve the texture and lower the amount of C. These are known techniques in the art.
  • the final cold rolling reduction ratio when the final cold rolling reduction ratio is under 80%, the ⁇ 110 ⁇ 001> texture broadens to the point of making it impossible to obtain high magnetic flux density.
  • a final cold rolling reduction ratio of over 92% reduces the ⁇ 110 ⁇ 001> texture to such an extremely low level that the secondary recrystallization becomes unstable.
  • the annealing of the hot-rolled strip is conducted mainly for the purpose of eliminating the nonuniformity of the texture/inhibitor dispersion that occurs in the strip during hot rolling.
  • the annealing can be effected on the hot-rolled strip or be effected prior to the final cold rolling.
  • At least one continuous annealing is preferably conducted before the final cold rolling in order to even out the heat hysteresis that arises during hot rolling.
  • the final cold rolling can be conducted at normal temperature, holding the strip the temperature range of 100 ⁇ 300°C for at least one minute during at least one final cold rolling pass improves the primary recrystallization texture and markedly enhances the magnetic characteristics.
  • heating rate between room temperature and 650 ⁇ 950°C in the decarburization annealing not less than 100°C/sec improves the primary recrystallization texture and enhances the magnetic characteristics.
  • Various methods are available for securing the heating rate. These include resistance heating, induction heating, and direct energy transfer heating. It is known from JP-B-(examined published Japanese patent application) 6-51887 , among others, that speeding up the heating rate increases the Goss orientation in the primary recrystallization texture and reduces the secondary recrystallization grain diameter. While JP-B-6-51887 specifices a heating rate of not less than 40°C/sec, in the present invention the heating rate is effective even at 100°C/sec and is preferably 150°C/sec or higher.
  • the decarburization annealing temperature is specified as not lower than 650°C because the effect is low below this temperature owing to incomplete recrystallization, and is specified as not higher than 950°C because decarburization annealing temperatures in excess of 950°C are not used in the production of grain-oriented electrical steel sheet.
  • Table 1 shows the composition of molten steels produced by an ordinary method
  • Table 2 shows the production conditions and the resulting product characteristics.
  • Continuous annealing was conducted at 1100°C for 150 seconds followed by cooling at 20°C/sec.
  • Annealing was then conducted at 850°C for 90 ⁇ 150 seconds in a mixed atmosphere of H 2 and N 2 having a dew point of 65°C.
  • This decarburization annealing was conducted at different heating rates of 50°C/sec, 110°C/sec and 180°C/sec.
  • Nitriding by the designated method before and after coating with an annealing separator composed mainly of MgO and secondary recrystallization annealing were then conducted.
  • Nitriding method A: Nitriding of running strip B : Addition of MnN to annealing separator
  • Fig. 1 shows the glass film defect rate when production was carried out under the following conditions using a material having the compositions set out below.
  • Each was heated to 1200 ⁇ 1300°C, formed into a 2.3 mm-thick hot-rolled strip, subjected to hot-rolled strip annealing at 980°C for 120 sec, pickled, cold-rolled to a sheet thickness of 1.55 mm, annealed at 1100°C for 150 sec, and final cold-rolled to a sheet thickness of 0.23 mm.
  • the sheet was held at 180 ⁇ 220°C for not less than 2 min in at least two passes.
  • the decarburization annealing temperature has to be changed to obtain primary recrystallization grains of uniform diameter, the oxide layer is not constant, and the glass film defect rate varies and is poor in absolute value.
  • the decarburization annealing temperature can be constant, the oxide layer is substantially constant, and the glass film defect rate is good and stable.
  • Figs. 2 and 3 show how the magnetic characteristics differed depending on whether or not nitriding was conducted in the case of sheets of 0.23 mm and 0.27 mm thickness.
  • the strip was subjected to hot-rolled strip annealing at 980°C for 120 seconds, pickled, cold-rolled to a sheet thickness of 1.55 mm, annealed at 1100°C for 150 seconds, and final cold-rolled to the sheet thickness of 0.23 mm.
  • the strip was subjected to hot-rolled strip annealing at 1120°C for 120 seconds, pickled, and final cold-rolled to the sheet thickness of 0.27 mm.
  • Both nitrided (0.005 ⁇ 0.013% nitriding on a running strip in an ammonia atmosphere) and un-nitrided 0.23 mm sheets and 0.27 mm sheets were produced.

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Claims (8)

  1. Procédé de production d'une tôle d'acier électrique à grains orientés, comprenant les étapes de réchauffage à une température dans la plage de 1260°C à 1350°C d'une ébauche comprenant, en % en poids, de 0,025 à 0,10 % de C, de 2,5 à 4,0 % de Si, de 0,010 à 0,035 % d'Al soluble dans l'acide, de 0,0030 à 0,010 % de N, Seq = (S + 0,406 Se) de 0,008 à 0,05 %, de 0,02 à 0,20 % de Mn, de 0,02 à 0,30 % de Cr, facultativement au moins l'un choisi parmi de 0,02 à 0,30 % d'au moins l'un parmi Sn, Sb et P, de 0,01 à 0,30 % de Cu, de 0,03 à 0,30 % de Ni et de 0,008 à 0,3 % d'au moins l'un parmi Mo et Cd, le complément étant Fe et les impuretés inévitables, le laminage à chaud de l'ébauche en une bande laminée à chaud, facultativement le recuit de la bande laminée à chaud, la soumission à un laminage à froid ou à deux laminages à froid ou plus de la bande laminée à chaud avec un recuit intermédiaire pour former une épaisseur de tôle finale, le recuit de décarburation de la tôle laminée à froid, le revêtement de la tôle avec un séparateur de recuit composé principalement de MgO et la soumission à un recuit de finition final, dans lequel le procédé est caractérisé en ce qu'il comprend en outre l'étape de nitruration de la tôle d'acier de la fin du recuit de décarburation au début de la recristallisation secondaire et dans lequel au moins un élément choisi parmi les sulfures et des séléniures est utilisé en tant que premier inhibiteur et au moins un nitrure formé par la nitruration est utilisé en tant que second inhibiteur et les grains de recristallisation primaire après l'achèvement du recuit de décarburation ont un diamètre moyen de grain non inférieur à 7 µm et non supérieur à 15 µm.
  2. Procédé de production d'une tôle d'acier électrique à grains orientés, comprenant les étapes de réchauffage à une température supérieur à 1050°C et inférieure à 1350°C d'une ébauche formant une épaisseur initiale d'environ 30 à 70 mm comprenant, en % en poids, de 0,025 à 0,10 % de C, de 2,5 à 4,0 % de Si, de 0,010 à 0,035 % d'Al soluble dans l'acide, de 0,0030 à 0,010 % de N, Seq = (S + 0,406 Se) de 0,008 à 0,05 %, de 0,02 à 0,20 % de Mn, de 0,02 à 0,30 % de Cr, facultativement au moins l'un choisi parmi de 0,02 à 0,30 % d'au moins l'un parmi Sn, Sb et P, de 0,01 à 0,30 % de Cu, de 0,03 à 0,30 % de Ni et de 0,008 à 0,3 % d'au moins l'un parmi Mo et Cd et le complément étant Fe et les impuretés inévitables, le laminage à chaud de l'ébauche en une bande laminée à chaud, facultativement le recuit de la bande laminée à chaud, la soumission à un laminage à froid ou à deux laminages à froid ou plus de la bande laminée à chaud avec un recuit intermédiaire pour former une épaisseur de tôle finale, le recuit de décarburation de la tôle laminée à froid, le revêtement de la tôle avec un séparateur de recuit composé principalement de MgO et la soumission à un recuit de finition final, dans lequel le procédé est caractérisé en ce qu'il comprend en outre l'étape de nitruration de la tôle d'acier de la fin du recuit de décarburation au début de la recristallisation secondaire et dans lequel au moins un élément choisi parmi les sulfures et des séléniures est utilisé en tant que premier inhibiteur et au moins un nitrure formé par la nitruration est utilisé en tant que second inhibiteur, dans lequel l'épaisseur initiale d'une ébauche pour la tôle d'acier électrique à grains orientés est dans la plage d'environ 30 mm à 70 mm et les grains de recristallisation primaire après l'achèvement du recuit de décarburation ont un diamètre de grain moyen non inférieur à 7 µm et non supérieur à 15 µm.
  3. Procédé de production d'une tôle d'acier électrique à grains orientés excellente en terme de caractéristiques magnétiques selon la revendication 1 ou 2, dans lequel l'étape de nitruration de la tôle d'acier après recuit de décarburation est effectuée sur une bande défilante dans une atmosphère de gaz mixte contenant de l'hydrogène, de l'azote et de l'ammoniac pour augmenter la quantité d'azote dans la tôle d'acier de 0,001 à 0,020 % en poids.
  4. Procédé de production d'une tôle d'acier électrique à grains orientés excellente en terme de caractéristiques magnétiques selon l'une quelconque des revendications 1 à 3, dans lequel le chauffage durant le recuit de décarburation est conduit à une vitesse de chauffage non inférieure à 100°C/s à partir du début de la montée en température jusqu'à 650 à 950°C.
  5. Procédé de production d'une tôle d'acier électrique à grains orientés excellente en terme de caractéristiques magnétiques selon l'une quelconque des revendications 1 à 4, dans lequel la température de la bande est ajustée à des températures dans les plages suivantes durant le laminage à chaud: 850 + 2500 × Seq + 400 × Mn ≤ FOT °C ≤ 1100 + 3000 × Seq + 800 × Mn ≤ 1350 ⁢ °C
    Figure imgb0009
     où FOT: température de début du laminage à chaud de finition (°C), 850 + 2500 × Seq + 400 × Mn ≤ FT °C ≤ 1050 + 3000 × Seq + 800 × Mn ≤ 1350 ⁢ °C
    Figure imgb0010
     où FT : température de fin du laminage à chaud de finition (°C).
  6. Procédé de production d'une tôle d'acier électrique à grains orientés excellente en terme de caractéristiques magnétiques selon l'une quelconque des revendications 1 à 5, dans lequel les conditions de recuit de bande laminée à chaud sont ajustées à une température maximale de 950 à 1150°C et une durée de recuit non inférieure à 30 secondes et non supérieure à 600 secondes.
  7. Procédé de production d'une tôle d'acier électrique à grains orientés excellente en terme de caractéristiques magnétiques selon l'une quelconque des revendications 1 à 6; dans lequel le laminage à froid est conduit à un rapport de réduction de laminage à froid final de 80 à 92 %
  8. Procédé de production d'une tôle d'acier électrique à grains orientés excellente en terme de caractéristiques magnétiques selon l'une quelconque des revendications 1 à 7, dans lequel la bande est maintenue dans la plage de température de 100 à 300°C pendant au moins 1 min durant au moins une passe de laminage à froid finale du laminage à froid.
EP99105071.7A 1998-03-30 1999-03-23 Procédé de fabrication d'une tôle d'acier à grains orientés presentant d'excellentes caracteristiques magnétiques Expired - Lifetime EP0947597B2 (fr)

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KR100501002B1 (ko) * 2000-05-24 2005-07-18 주식회사 포스코 방향성 전기강판의 제조방법
EP1162280B1 (fr) * 2000-06-05 2013-08-07 Nippon Steel & Sumitomo Metal Corporation Procédé de fabrication d'une tôle d'acier électrique à grains orientés presentant d'excellentes caracteristiques magnétiques
KR100501003B1 (ko) * 2000-06-16 2005-07-18 주식회사 포스코 방향성 전기강판의 제조방법
IT1316026B1 (it) 2000-12-18 2003-03-26 Acciai Speciali Terni Spa Procedimento per la fabbricazione di lamierini a grano orientato.
KR100544637B1 (ko) * 2001-12-24 2006-01-24 주식회사 포스코 자기적 성질이 우수한 방향성 전기강판의 제조방법
DE10311215B4 (de) * 2003-03-14 2005-09-15 Thyssenkrupp Electrical Steel Gmbh Verfahren zum Herstellen von kornorientiertem, kaltgewalztem Elektroblech oder -band
KR100721822B1 (ko) * 2005-12-20 2007-05-28 주식회사 포스코 저철손 고자속밀도를 갖는 방향성 전기강판 제조방법
KR100957911B1 (ko) * 2007-12-28 2010-05-13 주식회사 포스코 자성이 우수한 방향성 전기강판 및 그 제조방법
US8303730B2 (en) 2008-09-10 2012-11-06 Nippon Steel Corporation Manufacturing method of grain-oriented electrical steel sheet
KR101051743B1 (ko) * 2008-12-03 2011-07-25 주식회사 포스코 자기특성이 우수한 방향성 전기강판 및 그 제조방법
BRPI1010318B1 (pt) 2009-04-06 2018-02-06 Nippon Steel & Sumitomo Metal Corporation Método de tratamento do aço para chapa de aço elétrico com grão orientado e método de produção de chapa de aço elétrico com grão orientado
DE102011054004A1 (de) 2011-09-28 2013-03-28 Thyssenkrupp Electrical Steel Gmbh Verfahren zum Herstellen eines kornorientierten, für elektrotechnische Anwendungen bestimmten Elektrobands oder -blechs
CN103429775B (zh) 2011-12-16 2015-09-23 Posco公司 具有优良磁性能的晶粒取向电工钢板的制备方法
KR101521253B1 (ko) * 2012-11-15 2015-05-18 주식회사 포스코 방향성 전기강판 및 그의 제조방법
KR101480498B1 (ko) 2012-12-28 2015-01-08 주식회사 포스코 방향성 전기강판 및 그 제조방법
CZ305521B6 (cs) * 2014-05-12 2015-11-11 Arcelormittal Ostrava A.S. Pás z orientované transformátorové oceli a způsob jeho výroby
KR101677551B1 (ko) * 2014-12-18 2016-11-18 주식회사 포스코 방향성 전기강판 및 그 제조방법
DE102017220714B3 (de) * 2017-11-20 2019-01-24 Thyssenkrupp Ag Optimierung des Stickstofflevels während der Haubenglühung

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KR19990078406A (ko) 1999-10-25
DE69923102T3 (de) 2015-10-15
DE69923102T2 (de) 2005-12-29
EP0947597A3 (fr) 2001-01-31
DE69923102D1 (de) 2005-02-17
EP0947597A2 (fr) 1999-10-06

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