EP0162710B1 - Procédé pour la production de tôle en acier au silicium à grain orienté - Google Patents

Procédé pour la production de tôle en acier au silicium à grain orienté Download PDF

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Publication number
EP0162710B1
EP0162710B1 EP19850303595 EP85303595A EP0162710B1 EP 0162710 B1 EP0162710 B1 EP 0162710B1 EP 19850303595 EP19850303595 EP 19850303595 EP 85303595 A EP85303595 A EP 85303595A EP 0162710 B1 EP0162710 B1 EP 0162710B1
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Prior art keywords
steel sheet
annealing
subjected
cold rolled
elements
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EP19850303595
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German (de)
English (en)
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EP0162710A3 (en
EP0162710A2 (fr
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Yoshiaki C/O Research Laboratories Iida
Katsuo C/O Research Laboratories Iwamoto
Isao C/O Research Laboratories Matoba
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JFE Steel Corp
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Kawasaki Steel Corp
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Priority claimed from JP10369684A external-priority patent/JPS60248816A/ja
Priority claimed from JP11379084A external-priority patent/JPS60258412A/ja
Priority claimed from JP25580784A external-priority patent/JPS61136627A/ja
Priority claimed from JP4494085A external-priority patent/JPS61204314A/ja
Application filed by Kawasaki Steel Corp filed Critical Kawasaki Steel Corp
Publication of EP0162710A2 publication Critical patent/EP0162710A2/fr
Publication of EP0162710A3 publication Critical patent/EP0162710A3/en
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
    • C21D8/1277—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties involving a particular surface treatment
    • C21D8/1283—Application of a separating or insulating coating
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
    • 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

Definitions

  • the present invention relates to a method for producing grain-oriented silicon steel sheets, and particularly relates to a method for producing grain-oriented silicon steel sheets having low iron loss without lowering their magnetic induction.
  • Grain-orientated silicon steel sheets are required to have high magnetic induction and low iron loss.
  • various methods for lowering the iron loss for example, a method wherein a steel having a high Si content is used; a method wherein a product steel sheet having a small thickness is produced; a method wherein secondary recrystallization grains highly aligned to (110)[001] orientation, that is, to Goss orientation are developed; a method wherein secondary recrystallization grains having small size are developed; and the like.
  • Methods for developing secondary recrystallization grains highly aligned to Goss orientation are known, for example, a method disclosed in Japanese Patent Application Publication No.
  • the secondary recrystallized grains are surely and highly aligned to Goss orientation, and as a result a grain-oriented silicon steel sheet having high magnetic induction can be obtained.
  • the secondary recrystallized grains are always of coarse grain size, and the resulting grain-oriented silicon steel sheet still does not have a satisfactorily low iron loss.
  • the resulting grain-oriented silicon steel sheet has low magnetic induction and high iron loss.
  • the object of the present invention is to obviate the drawbacks of the above described conventional techniques, and to provide a method whereby consistently stably grain oriented silicon steel sheets having excellent magnetic properties are produced, and wherein secondary recrystallization grains highly aligned to Goss orientation are developed and further the crystal grains are developed into a small size without forming into coarse grain size. Thereby the iron loss of the product steel sheet is lowered.
  • a method wherein at least one member selected from the group consisting of elements of Ge, Sn, Pb, As, Bi and Zn and compounds containing these elements is applied to the surfaces of a finally cold rolled steel sheet before the decarburization annealing, or after the decarburization annealing and before the application of an annealing separator during the course of the production of a grain-oriented silicon steel sheet; a method wherein a step for subjecting a finally cold rolled steel sheet to a preliminary annealing at a temperature within the range of 500-700°C and a step for applying at least one member selected from the group consisting of elements of Ge, Sn, Pb, As, Bi and Zn and compounds containing these elements to the surfaces of a finally cold rolled steel sheet are carried out before the decarburization annealing of the finally cold rolled steel sheet during
  • the present invention is based on the above described discoveries.
  • a first aspect of the present invention lies in a method of producing grain oriented silicon steel sheets, wherein a hot rolled silicon steel sheet containing at least one of S, Se and Te as an inhibitor to the growth of primary recrystallization grains is subject to at least one stage cold rolling.
  • the finally cold rolled steel sheet is subjected to a decarburization annealing, and the decarburized steel sheet is coated with an annealing separator consisting mainly of MgO, and then subjected to a final annealing.
  • the invention comprises applying uniformly at least one member selected from the group consisting of the elements Ge, Sn, Pb, As, Bi and Zn and compounds containing these elements to the surfaces of the finally cold rolled steel sheet before the decarburization annealing.
  • At least one member selected from the group of elements Ge, Sn, Pb, As, Bi and Zn and compounds containing these elements is, advantageously, uniformly applied to the surfaces of the decarburized steel sheet, either additionally or exclusively, prior to the application of the annealing separator to the steel sheet surfaces.
  • At least one member selected from the group consisting of the elements Ge, Sn, Pb, As, Bi and Zn and compounds containing these elements is uniformly applied to the surfaces of the finally cold rolled steel sheet and then the coated steel sheet is subjected to a preliminary annealing at a temperature within the range 500-700°C for 0.5 to 10 minutes prior to the decarburization annealing.
  • the application of at least one member selected from the group consisting of the elements Ge, Sn, Pb, As, Bi and Zn and compounds containing these elements may also advantageously be made to the steel sheet, after the preliminary annealing, prior to the decarburization annealing.
  • a fourth aspect of the present invention lies in a method for producing grain oriented silicon steel sheets, wherein a hot rolled silicon steel sheet containing at least one of Si, Se and Te as an inhibitor for the growth of primary recrystallization grains is subjected to at least one stage cold rolling, the finally cold rolled steel sheet is subjected to a decarburization annealing, and the decarburized steel sheet is coated with an annealing separator consisting mainly of MgO, and then subjected to a final annealing wherein said annealing separator further contains at least one of Bi and compounds containing Bi.
  • the compounds containing Ge, ' Sn, Pb, As, Bi or Zn the following compounds are preferably used;
  • the above described elements and compounds containing these elements are applied to the surfaces of the finally cold rolled steel sheet before or after the steel sheet is subjected to the decarburization annealing.
  • the element or the compound is applied to the steel sheet surfaces before the decarburization annealing, it is advantageous that the element or the compound is applied to both surfaces of the steel sheet in an amount of at least 2 ⁇ g/m 2 calculated as element; and when the element or the compound is applied to the surfaces of the decarburized steel sheet, it is advantageous that the element or the compound is applied to both surfaces of the steel sheet in an amount of at least 10 ⁇ g/m 2 calculated as element.
  • the amount of Bi or Bi-containing compound to be contained in the annealing separator is preferably about 0.1-5.0% calculated as Bi (in the specification, abstract of the disclosure and claims, "%" relating to amount means “% by weight” unless otherwise indicated).
  • a hot rolled silicon steel sheet having a thickness of 3.0 mm and having a composition containing C: 0.049%, Si: 3.2%, Mn: 0.06% and further containing Se: 0.025% and Sb: 0.050% was annealed at 1,000°C for 1 minute and then subjected to two stage cold rolling with an intermediate annealing at 950°C for 2 minutes to produce a cold rolled sheet having a final gauge of 0.30 mm.
  • the finally cold rolled sheet was degreased, immersed in an aqueous dispersion of NaBi0 3 , and then subjected to a decarburization annealing for 3 minutes in wet hydrogen kept at 830°C.
  • the decarburized sheet was coated with an annealing separator consisting mainly of MgO, and then subjected to a final annealing at 1,200°C for 5 hours under hydrogen atmosphere.
  • an annealing separator consisting mainly of MgO
  • the concentration of NaBi0 3 , the temperature of the dispersion, and the immersing time were controlled so as to change variously the amount of Bi to be applied to the steel sheet surfaces.
  • secondary recrystallization texture was fully developed within the temperature range of 820-900°C.
  • Fig. 1 shows the influence of the applied amount of Bi to the steel sheet surfaces upon the grain size and magnetic properties of the resulting grain-oriented silicon steel sheet.
  • a hog rolled silicon steel sheet having a thickness of 3.0 mm and having a composition containing C: 0.049%, Si: 3.2%, Mn: 0.06% and further containing inhibitors A-D shown in the following Table 1 was annealed at 1,000°C for 1 minute, and then subjected to two stage cold rolling with an intermediate annealing at 950°C for 2 minutes to produce a finally cold rolled sheet having a final gauge of 0.30 mm.
  • the finally cold colled sheet after degreasing, was immersed in an aqueous solution of SnS0 4 , and then subjected to a decarburization annealing for 3 minutes in wet hydrogen kept at 830°C, and the decarburized steel sheet was coated with an annealing separator consisting mainly of MgO and then subjected to a final annealing at 1,200°C for 5 hours under hydrogen atmosphere.
  • the concentration of SnS0 4 , the temperature of the solution and the immersing time were controlled so as to change variously the amount of Sn to be applied to the steel sheet surfaces. Further, during the final annealing, the secondary recrystallization texture was fully developed within the temperature range of 820 ⁇ 900°C.
  • Fig. 2 shows the influence of the amount of Sn applied to the steel sheet surfaces upon the grain size and magnetic properties in the resulting grain-oriented silicon steel sheet.
  • a hot rolled silicon steel sheet having a thickness of 3.0 mm and having a composition containing C: 0.049%, Si: 3.2%, Mn: 0.06% and further containing Se: 0.025% and Sb: 0.050% was annealed at 1,000°C for 1 minute and then subjected to two stage cold rollings with an intermediate annealing at 950°C for 2 minutes to produce a finally cold rolled steel sheet having a final gauge of 0.3 mm.
  • the finally cold rolled sheet was degreased, and then subjected to a decarburization annealing for 3 minutes in wet hydrogen kept at 830°C, and further immersed in an aqueous dispersion of Pb0 2 .
  • the immersion-treated steel sheet was coated with an annealing separator consisting mainly of MgO, and then subjected to a final annealing at 1,200°C for 5 hours under hydrogen atmosphere.
  • the concentration of Pb0 2 , the temperature of the dispersion, and the immersing time were controlled so as to change variously the amount of Pb0 2 to be adhered to the steel sheet surfaces. Further, during the final annealing, secondary recrystallization texture was fully developed within the temperature range of 820-900°C.
  • Fig. 3 shows the influence of the amount of Pb applied to decarburized steel sheet surfaces upon the magnetic properties of the resulting grain-oriented silicon steel sheet.
  • the inventors have made the same experiment as described above with respect to elements of Pb, Ge, Sb, As, Zn and Bi and compounds containing Ge, Sb, As, Zn and Bi, and ascertained that the same result as that shown in Fig. 3 is obtained.
  • a hot rolled silicon steel sheet having a thickness of 2.5 mm and having a composition containing C: 0.049%, Si: 3.2%, Mn: 0.06% and further containing Se: 0.025% and Sb: 0.050% was annealed at 1,000°C for 1 minute and then subjected to two stage cold rollings with an intermediate annealing at 970°C for 2 minutes to produce a finally cold rolled sheet having a final gauge of 0.27 mm.
  • the finally cold rolled sheet after degreasing, was immersed for 10 seconds in an aqueous dispersion containing 100 mg/I of ZnO and kept at 30°C, and then squeezed by means of a pair of rubber rollers, and dried in an air bath kept at 200°C to adjust the amount of Zn to be applied to the steel sheet surfaces to 4.1 mg/m 2.
  • the thus treated steel sheet was subjected to a preliminary annealing at a temperature within the range of 500-700 0 C for 2 minutes in dry nitrogen, and then subjected to a decarburization annealing for 3 minutes in wet hydrogen kept at 830°C.
  • the decarburized steel sheet was coated with an annealing separator consisting mainly of MgO, and then subjected to a final annealing at 1,200°C for 5 hours under hydrogen atmosphere to produce a grain-oriented silicon steel sheet (this method of the third aspect of the present invention is indicated by the mark ⁇ in Fig. 4).
  • the modified conventional method (indicated by the mark A) is remarkably effective for improving the B 10 value of the resulting grain-oriented silicon steel sheet as compared with the conventional method (indicated by the mark O), but still has a drawback in that the resulting grain-oriented silicon steel sheet is rather high in the iron loss value as compared with the conventional method since the modified conventional method forms coarse secondary recrystallization structure having a remarkably large grain size.
  • the resulting grain-oriented silicon steel sheet does not have coarse crystal grains, but rather has small crystal grains, and as a result the grain-oriented silicon steel sheet has remarkably low iron loss value and further has remarkably high B 10 value.
  • This preliminary annealing is carried out at a temperature within the range of 500-700 0 C, preferably 500 ⁇ 650°C, for 0.5 to 10 minutes.
  • the reason is as follows.
  • the recrystallization begins generally at about 550°C, and proceeds rapidly as the temperature rises.
  • a recrystallization texture for the preferred magnetic properties of the resulting grain-oriented silicon steel sheet can be obtained at a temperature of not higher than 650°C.
  • the preliminary annealing temperature when the annealing temperature is low, treatment for a longer time is effective for the annealing; and when the annealing temperature is high, treatment for a shorter time is effective for the annealing.
  • a preliminary annealing for less than 0.5 minute or more than 10 minutes does not result in a satisfactory recrystallization texture, and the magnetic properties of the product steel sheet cannot thus be improved.
  • a hot rolled silicon steel sheet having a thickness of 2.2 mm and having the same composition as described above was annealed at 1,000°C for 1 minute, and then subjected to two stage cold rollings with an intermediate annealing at 970°C for 2 minutes to produce a finally cold rolled sheet having a final gauge of 0.23 mm.
  • the immersion-treated sheet was subjected to a decarburization annealing for 3 minutes in wet hydrogen kept at 830°C, then coated with an annealing separator consisting mainly of MgO, and then subjected to a final annealing at 1,200°C for 5 hours under hydrogen atmosphere to produce a grain-oriented silicon steel sheet (this method of the third aspect of the present invention is indicated by the mark A in Fig. 5).
  • Fig. 5 shows the magnetic properties of the resulting products.
  • the product obtained by the modified conventional method has remarkably higher magnetic induction B 10 than that of the product by the conventional method (indicated by the mark 0), but does not have a satisfactorily low iron loss due to the development of coarse crystal grains.
  • the product obtained by the method (indicated by the mark A) satisfying the conditions defined in the present invention has a remarkably low iron loss value due to the small crystal grain size in the product and further has remarkably high magnetic induction B lo .
  • a hot rolled silicon steel sheet having a thickness of 2.0 mm and having a composition containing C: 0.049%, Si: 3.2%, Mn: 0.06% and further containing Se: 0.025% and Sb: 0.050% was annealed at 1,000°C for 1 minute and then subjected to two stage cold rolling with an intermediate annealing at 950°C for 2 minutes to produce a finally cold rolled sheet having a final gauge of 0.23 mm.
  • a variant amount of Bi 2 (SO 4 ) 3 was combined with the annealing separator consisting mainly of MgO.
  • secondary recrystallization texture was fully developed within the temperature range of 820-900 0 C.
  • Fig. 6 illustrates the influence of the content of Bi 2 (S0 4 ) 3 in the annealing separator upon the magnetic properties of the resulting grain-oriented silicon steel sheet. It can be seen from Fig. 6 that, when an annealing separator contains 0.1-5.0%, calculated as Bi, of Bi 2 (S0 4 ) 3 , the product steel sheet has satisfactorily high magnetic induction B 10 and low iron loss W 17/50. Bi-containing compounds other than the above described Bi 2 (SO 4 ) 3 exhibited the same effect as that of Bi 2 (SO 4 ) 3 .
  • the steel should contain Si: 2.5-4.0%, C:0.02-0.06% and Mn: 0.02-0.20% and further contain at least one of S: 0.005-0.05%, Se: 0.005-0.05% and Te: 0.003-0.05%.
  • Si is used for obtaining satisfactorily low iron loss without sacrificing the yield in the cold rolling
  • C is used for forming fine crystal grains in the steps carried out after hot rolling
  • other ingredients are used for inhibiting effectively the growth of primary recrystallization grains.
  • the initial silicon steel contains the above described ingredients in the above described range. However, even when the amounts are outside of the above described ranges, the ingredients still have an appreciable effect.
  • the initial silicon steel to be used in the present invention has a composition consisting of the above described ingredients and the remainder being substantially Fe and incidental impurities.
  • the steel may occasionally contain grain boundary seggregation elements, such as Sb, As, Bi, Sn, Pb and the like, alone or in admixture in order to improve the effect of the inhibitors.
  • the addition of the grain boundary segregation element does not have any adverse influence upon the effect of the present invention.
  • the invention is not affected by the steel making or hot rolling methods employed, hence these processes may be carried out according to commonly known methods.
  • the annealing of a hot rolled sheet and the intermediate annealing in the cold rolling step are occasionally carried out at a temperature within the range of 750-1,000°C for a period of from 10 seconds to 10 minutes.
  • the hot rolled sheet after being occasionally annealed, is subjected to at least one stage cold rolling to produce a finaly cold rolled sheet having the final desired gauge.
  • the finally cold rolled sheet is degreased by a commonly known method, and then at least one member selected from the group consisting of elements of Ge, Sn, Pb, As, Bi and Zn and compounds containing these elements is applied to the surfaces of the steel sheet.
  • the method for applying the element or the element-containing compounds to the steel sheet surfaces can be any of immersion, spraying, application, electrodeposition, dropping, transfer printing and the like.
  • the amount of the element orthe element-containing compound to be applied to the surfaces of a steel sheet should be at least 2 pg/M2 calculated as element. It is preferable to apply the element or the element-containing compound to both surfaces of a steel sheet. However, it is not always necessary to apply the element or the element-containing compound to both surfaces of a steel sheet, and even when the element or ⁇ the element-containing compound is applied to only one surface of a steel sheet, the effect of the element appears. When the element or the element-containing compound is applied to one surface of a steel sheet, it is also necessary that the amount of element applied to one surface of the steel sheet is at least 2 pg/m 2 in order to produce a product steel sheet having excellent magnetic properties.
  • the above treated steel sheet is subjected to a decarburization annealing at a temperature of 700 ⁇ 900°C under an atmosphere containing hydrogen and steam until the C content in the steel sheet becomes about 0.003% or less.
  • the finally cold rolled and degreased steel sheet is subjected to a preliminary annealing such that the steel sheet is kept to a constant temperature within the range of 500-700 0 C for 0.5-10 minutes or its heated within the temperature range of 500 ⁇ 700°C at a heating rate of 50°C/min-400°C/min.
  • This preliminary annealing is effective in improving the primary recrystallization texture.
  • the preliminary annealing may be carried out before the above described application of the element or the application treatment may be carried out before and after the preliminary annealing.
  • the finally cold rolled and degreased steel sheet is directly subjected to a decarburization annealing at a temperature of 700-900 0 C under an atmosphere containing hydrogen steam until the C content in the steel sheet becomes about 0.003% or less, without carrying out the application of the element or a combination of the application of the element and the preliminary annealing.
  • at least one member selected from the group consisting of elements of Ge, Sn, Pb, As, Bi and Zn and compounds containing these elements is applied to the surfaces of the steel sheet.
  • the method for applying the element or the element-containing compound to the steel sheet surfaces can be any of immersion, spraying, application, electrodeposition, dropping, transfer printing, and the like.
  • the amount of the element or the compound containing the element to be applied to the surfaces of the steel sheet is at least 10 pg/m 2 calculated as element.
  • the amount is less than 10 pg/m 2 , the magnetic properties of the resulting grain-oriented silicon steel sheet are not satisfactorily improved.
  • it is not always necessary to apply the element or the element-containing compound to both surfaces of a steel sheet, and even when the element or the element-containing compound is applied to only one surface of a steel sheet, the effect of the element appears.
  • the amount of element applied to one surface of the steel sheet is at least 10 ⁇ g/m 2 in order to produce a product steel sheet having excellent magnetic properties.
  • the decarburized steel sheet may be occasionally subjected to the application of element.
  • the essential feature of the first aspect of the present invention lies in that the application of the element or a combination of the application of the element and the preliminary annealing is carried out during a process wherein the finally cold rolled and degreased steel sheet is subjected to a decarburization annealing and then coated with an annealing separator consisting mainly of MgO in a conventional method.
  • the final cold rolling, the application of the element, and the decarburization annealing can be carried out according to the following treatment orders.
  • the final cold rolling, the application treatment of element, the preliminary annealing and the decarburization annealing in the third aspect of the present invention can be carried out according to the following treatment orders.
  • a proper treatment order must be selected depending upon the magnetic properties of the desired product.
  • a hot rolled silicon steel sheet having a thickness of 3.0 mm and having a composition containing C: 0.049%, Si: 3.2%, Mn: 0.06% and further containing inhibitors shown in the above described Table 1 was annealed at 1,000°C for 1 minute, and then subjected to two stage cold rolling with an intermediate annealing at 950°C for 2 minutes to produce a finally cold rolled sheet having a final gauge of 0.30 mm.
  • the finally cold rolled sheet after degreasing, was immersed in an aqueous dispersion containing NaBi0 3 powder dispersed therein, passed through a pair of squeeze rollers and then dried.
  • the above treated steel sheet was subjected to a decarburization annealing at 830°C for 3 minutes in wet hydrogen, and the decarburized steel sheet was coated with an annealing separator consisting mainly of MgO, and then subjected to a final annealing at 1,200°C for 5 hours.
  • an annealing separator consisting mainly of MgO
  • the concentration of Bi, the temperature of the dispersion, and the immersing time were controlled so as to change variously the amount of Bi to be applied to the steel sheet surfaces.
  • secondary recrystallization texture was fully developed at a temperature within the range of 820-900 0 C.
  • Fig. 7 illustrates relationship between the concentration of Bi in the aqueous NaBi0 3 dispersion, and the magnetic properties of the resulting grain-oriented silicon steel sheet (final gauge: 0.30 mm).
  • Fig. 8 illustrates relationship between the immersing time of a finally cold rolled and degreased steel sheet in an aqueous NaBi0 3 dispersion having a Bi concentration of 208 mg/I, and the grain size and iron loss value of the resulting grain-oriented silicon steel sheet (final gauge: 0.23 mm).
  • a finally cold rolled and degreased steel sheet is immersed for at least 1 second in an aqueous dispersion containing a given element in a concentration of at least 10 mg/I.
  • the immersed steel sheet is passed occasionally through a pair of squeeze rollers and then dried.
  • the drying is a very important treatment in order to give satisfactorily high rust resistance to the resulting grain-oriented silicon steel sheet and further to give an excellent appearance to the coating film formed on the steel sheet surfaces.
  • the dispersion is formed into a sol or a colloidal dispersion or is fully stirred by means of a propeller or an ultrasonic wave in order to keep the concentration constant and to apply the element uniformly to the steel sheet surfaces.
  • the steel sheet is coated with an annealing separator consisting mainly of MgO.
  • a finally cold rolled and degreased steel sheet is directly subjected to the decarburization annealing without carrying out the above described application treatment of element or a combination of the application treatment of element and the preliminary annealing, and an annealing separator consisting mainly of MgO and containing 0.1-5.0% of Bi or a Bi-containing compound is applied to the decarburized steel sheet.
  • the annealing separator consisting mainly of MgO and containing 0.1-5.0% of Bi or a Bi-containing compound may be coated onto a decarburized steel sheet, which has already been subjected to the application of element or a combination of the application of element and the preliminary annealing in the first, second or third aspect of the present invention.
  • the steel sheet coated with the above described annealing separator was subjected to a final annealing comprising a recrystallization annealing at a temperature within the range of 800-1,000°C and a purification annealing at a temperature within the range of 1,100-1,250°C under hydrogen atmosphere subsequent to the recrystallization annealing.
  • the finaly annealed steel sheet was applied with a tension coating, and then subjected to a flattening annealing at a temperature within the range of 700-900°C.
  • Japanese Patent Application Publication No. 48;567/81 discloses a technique, wherein a compound containing any one of Al, Sn, As, Pb, Sb, Bi, Se and Te is applied to the surfaces of a cold rolled low-carbon aluminum killed steel sheet in an amount of at least 2 g/m 2 before the annealing of the steel sheet under a nitrogen-containing atmosphere, in order to prevent the nitriding of the steel sheet during the annealing. Further, this Japanese patent application publication discloses that the use of the above described element is also effective for preventing the deterioration of the electromagnetic properties of a silicon steel sheet due to its nitriding.
  • the magnetic properties of a silicon steel sheet can be remarkably improved by applying a very small amount of only several pg/ M 2 of element to its surface as illustrated in Figs. 1-3, and further the magnetic properties of silicon steel sheet can be remakarbly improved even by an annealing under an atmosphere not containing N 2 , that is, an annealing under H 2 or Ar atmosphere as illustrated in the following Examples 1, 2, 3, 4, 5, 7, 9, 10 and 14.
  • the magnetic properties of silicon steel are improved by preventing its nitriding, but are improved by giving to the steel a property entirely different from the prevention of nitriding. That is, the present invention has been accomplished based on a technical idea entirely different from that disclosed in the above described Japanese Patent Application Publication No. 48,567/81.
  • a hot rolled sheet having a thickness of 3 mm and having a composition containing C: 0.052%, Si: 3.36%, Mn: 0.065%, Se: 0.025% and Sb: 0.031 % was cold rolled into a thickness of 0.80 mm, and the first cold rolled sheet was intermediately annealed at 950°C for 1 minute and then secondly cold rolled into a final gauge of 0.30 mm.
  • the amount of Zn adhered to the dried steel sheet was 15 mg/m 2 .
  • the above treated steel sheet was subjected to a decarburization annealing for 3 minutes in wet hydrogen kept at 830°C, and the decarburized sheet was coated with an MgO slurry.
  • the coated sheet was dried and then subjected to a final annealing at 850°C for 50 hours and successively at 1,200°C for 10 hours under H 2 atmosphere.
  • Table 2 shows the magnetic properties and grain size of the resulting grain-oriented silicon steel sheet.
  • a grain-oriented silicon steel sheet was produced according to a conventional method, wherein the finally cold rolled and degreased steel sheet was not treated with the aqueous ZnS0 4 solution but was directly subjected to the decarburization annealing.
  • the magnetic properties and grain size of the product steel sheet are also shown in Table 2.
  • a hot rolled sheet having a thickness of 2 mm and having a composition containing C: 0.040%, Si: 3.05%, Mn: 0.08%, S: 0.021 % and Te: 0.005% was cold rolled into a thickness of 0.60 mm, and the first cold rolled sheet was intermediately annealed at 900°C for 1 minute and then secondly cold rolled into a final gauge of 0.23 mm.
  • the above treated steel sheet was subjected to a decarburization annealing in wet hydrogen kept at 830°C, and the decarburized sheet was coated with an MgO slurry.
  • the coated sheet was dried and then subjected to a final annealing at 880°C for 20 hours under an Ar atmosphere and successively at 1,200°C for 10 hours under an H 2 atmosphere.
  • Table 3 shows the magnetic properties and grain size of the resulting grain-oriented silicon steel sheet together with those of a comparative grain-oriented silicon steel sheet produced by a conventional method.
  • a hot rolled sheet having a thickness of 2.0 mm and having a composition containing C: 0.048%, Si: 3.4%, Mn: 0.07%, Se: 0.02% and Sb: 0.03% was cold rolled into a final gauge of 0.60 mm.
  • the finally cold rolled sheet was immersed for 1 minute in an aqueous dispersion containing 300 mg/I of PbS0 4 and kept at 80°C, and then passed through a pair of rubber squeeze rollers.
  • the squeezed sheet was dried in an air bath kept at 150°C.
  • the amount of PbO applied to both surfaces of the dried steel sheet was 1 mg/m 2 .
  • the above treated steel sheet was subjected to a decarburization annealing at 840°C for 3 minutes under an atmosphere consisting of 50% by volume of H 2 and the remainder being N 2 and having a dew point of 60°C, and then applied with an MgO slurry, and further subjected to a final annealing at 880°C for 30 hours under an H 2 atmosphere and successively at 1,200°C for 10 hours under an H 2 atmosphere.
  • Table 4 shows the magnetic properties and grain size of the product steel sheet together with those of a comparative product steel sheet produced without the adhesion of Pb to the steel sheet surfaces according to the conventional method.
  • a hot rolled sheet having a thickness of 3 mm and having a composition containing C: 0.051 %, Si: 3.34%, Mn: 0.067%, S: 0.027% and Sb: 0.032% was cold rolled into a thickness of 0.80 mm, and the first cold rolled sheet was intermediately annealed at 950°C for 1 minute and then secondly cold rolled into a final gauge of 0.3 mm. After degreasing, the finally cold rolled sheet was immersed for 3 seconds in an aqueous dispersion containing 130 mg/I (75 mg/l calculated as As) of NaAs0 2 and kept at 30°C, passed through a pair of rubber squeeze rollers and then dried.
  • the above treated steel sheet was subjected to a decarburization annealing at 830°C for 3 minutes in wet hydrogen, and the decarburized sheet was applied with an MgO slurry. After drying, the applied sheet was subjected to a final annealing at 850°C for 50 hours and successively at 1,200°C for 10 hours under an H 2 atmosphere.
  • Table 5 shows the magnetic properties and grain size of the resulting product steel sheet together with those of a comparative product steel sheet produced by a conventional method.
  • a hot rolled sheet having a thickness of 3 mm and having a composition containing C: 0.040%, Si: 3.22%, Mn: 0.089%, Se: 0.028% and Sb: 0.027% was annealed at 1,000°C for 1 minute, and then pickled.
  • the pickled sheet was cold rolled into a thickness of 0.87 mm, and the first cold rolled sheet was intermediately annealed at 980°C for 1 minute and then secondly cold rolled into a final gauge of 0.30 mm.
  • the finally cold rolled sheet was immersed for 15 seconds in an aqueous dispersion containing 800 mg/I of Bi 2 0 3 and kept at 30°C, and then passed through a pair of rubber squeeze rollers, and further dried in an air bath kept at 150°C.
  • the amount of Bi applied to the steel sheet surfaces was 4.9 mg/ m 2.
  • the above treated steel sheet was subjected to a prelimary annealing at 600°C for 1 minute, and then to a decarburization annealing at 830°C for 3 minutes under an atmosphere consisting of 50% by volume of H 2 and the remainder being N 2 and having a dew point of 60°C.
  • the decarburized steel sheet was coated with an MgO slurry, and then subjected to a final annealing at 860°C for 35 hours under an Ar atmosphere and successively at 1,200°C for 10 hours under an H 2 atmosphere.
  • Table 6 shows the magnetic properties of the resulting grain-oriented silicon steel sheet together with those of a comparative grain-oriented silicon steel sheet produced by a conventional method.
  • a hot rolled sheet having a thickness of 2.2 mm and having a composition containing C: 0.049%, Si: 3.38%, Mn: 0.088%, S: 0.027% and Sb: 0.023% was annealed at 950°C for 1 minute, and then pickled.
  • the pickled sheet was cold rolled into a thickness of 0.58 mm, and the first cold rolled sheet was intermediately annealed at 980°C for 1.5 minutes and then secondly cold rolled into a final gauge of 0.23 mm.
  • the finally cold rolled sheet was subjected to a preliminary annealing at 550°C for 4 minutes, and the preliminarily annealed sheet was immersed for 10 seconds in an aqueous dispersion containing 100 mg/I of SnO 2 and kept at 50°C, and then passed through a pair of rubber squeeze rollers, and further dried in an air bath kept at 200°C.
  • the amount of Sn applied to both surfaces of the steel sheet was 0.96 mg/ m 2.
  • the above treated steel sheet was subjected to a decarburization annealing at 840°C for 3 minutes under an atmosphere consisting of 55% by volume of H 2 and the remainder being N 2 and having a dew point of 55°C.
  • the decarburized steel sheet was coated with an MgO slurry, and then subjected to a final annealing at 870°C for 25 hours under an N 2 atmosphere and successively at 1,200°C for 10 hours under an H 2 atmosphere.
  • Table 7 shows the magnetic properties of the resulting grain-oriented silicon steel sheet together with those of a comparative grain-oriented silicon steel sheet produced by a conventional method.
  • the product steel sheet of the present invention has a remarkably lower' iron loss value and higher B 10 value than those of the comparative product steel sheet.
  • a hot rolled sheet having a thickness of 2 mm and having a composition containing C: 0.041%, Si: 3.24%, Mn: 0.089%, S: 0.027% and Te: 0.005% was annealed at 970°C for 1 minute, and then pickled.
  • the pickled sheet was cold rolled into a thickness of 0.50 mm, and the first cold rolled sheet was intermediately annealed at 980°C for 1 minute and then secondly cold rolled into a final gauge of 0.20 mm.
  • the finally cold rolled sheet was immersed for 20 seconds in an aqueous dispersion containing 1.5 g/I of PbS0 4 and kept at 80°C, and then passed through a pair of rubber squeeze rollers, and further dried in an air bath kept at 200°C.
  • the amount of Pb applied to both surfaces of the steel sheet was 1.25 mg/ m 2 .
  • the above treated steel sheet was subjected to a preliminary annealing by heating the steel sheet at a heating rate of 80°C/min.
  • decarburized steel sheet was coated with an MgO slurry, and then subjected to a final annealing at 860°C for 35 hours under an Ar atmosphere and successively at 1,200°C for 10 hours under an H 2 atmosphere.
  • Table 8 shows the magnetic properties of the resulting product steel sheet together with those of a comparative product steel sheet produced by a conventional method.
  • a hot rolled sheet having a thickness of 2.5 mm and having a composition containing C: 0.047%, Si: 3.35%, Mn: 0.090% and Se: 0.024% was annealed at 950°C for 2 minutes, and then pickled.
  • the pickled sheet was cold rolled into a thickness of 0.71 mm, and the first cold rolled sheet was intermediately annealed at 980°C for 1 minute and then secondly cold rolled into a final gauge of 0.27 mm.
  • the finally cold rolled sheet was immersed for 11 seconds in an aqueous dispersion containing 50 mg/l of NaAs0 2 and kept at 25°C and then passed through a pair of rubber squeeze rollers, and further dried in an air bath kept at 150°C.
  • the amount of As applied to both surfaces of the steel sheet was 150 pg/m 2 .
  • the above treated steel sheet was subjected to a preliminary annealing by heating the steel sheet at a heating rate of 50°C/min within the temperature range of 500-700°C under an atmosphere consisting of 53% by volume of H 2 and the remainder being N 2 and having a dew point of 57°C, and successively subjected to a decarburization annealing at 830°C for 3 minutes under the same atmosphere as described above.
  • the decarburized steel sheet was applied with an MgO slurry, and then subjected to a final annealing at 865°C for 40 hours under an N 2 atmosphere and successively at 1,200°C for 10 hours under an H 2 atmosphere.
  • Table 9 shows the magnetic properties of the product steel sheet of the present invention together with a comparative product steel sheet produced by a conventional method. It can be seen from Table 9 that the product steel sheet of the present invention has remarkably excellent magnetic properties as compared with those of the comparative product steel sheet.
  • a hot rolled sheet having a thickness of 2 mm and having a composition containing C: 0.041%, Si: 3.05%, Mn: 0.081%, S: 0.022% and Te: 0.006% was cold rolled into a thickness of 0.60 mm, and the first cold rolled sheet was intermediately annealed at 900°C for 1 minute and then secondly cold rolled into a final gauge of 0.23 mm. After degreasing, the finally cold rolled sheet was coated with an aqueous dispersion containing 58 mg/I of finely divided Ge and kept at 50°C by means of a pair of fluted rolls. After being left to stand for 8 seconds, the coated steel sheet was passed through a pair of rubber squeeze rollers and then dried.
  • the above treated steel sheet was subjected to a decarburization annealing in wet hydrogen with a heat cycle consisting of a heating at 580°C for 3 minutes and a heating at 850°C for 3 minutes.
  • the decarburized steel sheet was coated with an MgO slurry, dried and then subjected to a final annealing at 870°C for 25 hours under an Ar atmosphere and successively at 1,200°C for 10 hours under an H 2 atmosphere.
  • Table 10 shows the magnetic properties and grain size of the resulting grain-oriented silicon steel sheet together with a comparative grain-oriented silicon steel sheet produced by a conventional method.
  • a hot rolled sheet having a thickness of 3.0 mm and having a composition containing C: 0.047%, Si: 3.38%, Mn: 0.089%, Se: 0.027% and Sb: 0.026% was annealed at 920°C for 3 minutes and then cold rolled into a thickness of 1.0 mm, and the first cold rolled sheet was intermediately annealed at 950°C for 2 minutes and then secondly cold rolled into a final gauge of 0.30 mm. After degreasing, the finally cold rolled sheet was subjected to a decarburization annealing at 830°C for 3 minutes under an atmosphere consisting of 50% by volume of H 2 and the remainder being N 2 and having a dew point of 60°C.
  • the decarburized steel sheet was coated with an aqueous dispersion containing 200 mg/l of Ge0 2 and kept at 35°C by means of a pair of fluted rolls. After being left to stand for 5 seconds, the coated steel sheet was passed through a pair of rubber squeeze rollers, and then dried in an air bath kept at 180°C. The above treated steel sheet was coated with an MgO slurry, dried and then subjected to a final annealing at 870°C for 30 hours under an Ar atmosphere and successively at 1,200°C for 10 hours under an H 2 atmosphere.
  • Table 11 shows the magnetic properties of the resulting grain-oriented silicon steel sheet together with those of a comparative grain-oriented silicon steel sheet produced by a conventional method.
  • a hot rolled sheet having a thickness of 2 mm and having a composition containing C: 0.051 %, Si: 3.33%, Mn: 0.069%, Se: 0.027% and Te: 0.007% . was annealed at 1,000°C for 1 minute, and then cold rolled into a thickness of 0.60 mm, and the first cold rolled sheet was intermediately annealed at 950°C for 1 minute and then secondly cold rolled into a final gauge of 0.23 mm.
  • the finally cold rolled sheet was subjected to a decarburization annealing at 835°C for 3 minutes under an atmosphere consisting of 50% by volume of H 2 and the remainder being N 2 and having a dew point of 60°C.
  • the decarburized steel sheet was immersed for 9 seconds in an aqueous dispersion containing 200 mg/l of SnO 2 and kept at 30°C, and then passed through a pair of rubber squeeze rollers, and further dried in an air bath kept at 200°C.
  • the amount of Sn applied to the steel sheet surfaces was 3 mg/m 2 .
  • the above treated steel sheet was applied with an MgO slurry, and then subjected to a final annealing at 870°C for 25 hours under an N 2 atmosphere and successively at 1,200°C for 10 hours under an H 2 atmosphere.
  • Table 12 shows the magnetic properties and grain size of the resulting grain-oriented silicon steel sheet together with those of a comparative grain-oriented silicon steel sheet produced without the application of Sn0 2 according to a conventional method.
  • a hot rolled sheet having a thickness of 3.0 mm and having a composition containing C; 0.048%, Si: 3.28%, Mn: 0.088%, S: 0.025% and Te: 0.008% was annealed at 900°C for 3 minutes and then cold rolled into a thickness of 1.0 mm, and the first cold rolled sheet was intermediately annealed at 950°C for 3 minutes and then secondly cold rolled into a final gauge of 0.30 mm. After degreasing, the finally cold rolled sheet was subjected to a decarburization annealing at 830°C for 3 minutes under an atmosphere consisting of 50% by volume of H 2 and the remainder being N 2 and having a dew point of 60°C.
  • the decarburized steel sheet was immersed for 18 seconds in an aqueous dispersion containing 220 mg/I of As 2 S 3 and kept at 40°C, and then passed through a pair of rubber squeeze rollers, and further dried in an air bath kept at 200°C.
  • the amount of As applied to the steel sheet surfaces was 1.4 g/m 2 .
  • the above treated steel sheet was coated with an MgO slurry, dried, and then subjected to a final annealing at 865°C for 30 hours under an N 2 atmosphere and successively at 1,200°C for 10 hours under an H 2 atmosphere.
  • Table 13 shows the magnetic properties and grain size of the product steel sheet together with those of a comparative product steel sheet produced by a conventional method, and illustrates that the present invention is remarkably effective.
  • a hot rolled sheet having a thickness of 2.0 mm and having a composition containing C: 0.040%, Si: 3.35%, Mn: 0.068%, Se: 0.022% and Sb: 0.029% was annealed at 1,000°C for 1 minute, and then cold rolled into a thickness of 0.60 mm, and the first cold rolled sheet was intermediately annealed at 950°C for 1 minute and then secondly cold rolled into a final gauge of 0.23 mm.
  • the finally cold rolled sheet was subjected to a decarburization annealing at 840°C for 3 minutes under an atmosphere consisting of 50% by volume of H 2 and the remainder being N 2 and having a dew point of 60°C.
  • the decarburized steel sheet was immersed for 30 seconds in an aqueous dispersion containing 400 mg/l of Bi 2 0 3 and kept at 80°C, and then passed through rubber squeeze rollers, and further dried in an air bath kept at 150°C.
  • the amount of Bi applied to the steel sheet surfaces was 2.5 mg/m 2 .
  • the above treated steel sheet was coated with an MgO slurry, and then subjected to a final annealing at 870°C for 30 hours -under an N 2 atmosphere and successively at 1,200°C for 10 hours under an H 2 atmosphere.
  • Table 14 shows the magnetic properties and grain size of the resulting product steel sheet together with those of a comparative product steel sheet produced without the application of Bi 2 0 3 according to a conventional method.
  • a hot rolled sheet having a thickness of 3.0 mm and having a composition containing C: 0.047%, Si: 3.28%, Mn: 0.089%, S: 0.021 % and Te: 0.006% was annealed at 900°C for 3 minutes and then cold rolled into a thickness of 1.0 mm, and the first cold rolled sheet was intermediately annealed at 950°C for 3 minutes and then secondly cold rolled into a final gauge of 0.30 mm. After degreasing, the finally cold rolled sheet was subjected to a decarburization annealing at 830°C for 3 minutes under an atmosphere consisting of 50% by volume of H 2 and remainder being N 2 and having a dew point of 60°C.
  • the decarburized steel sheet was immersed for 10 seconds in an aqueous solution containing 80 mg/I of ZnS0 4 and kept at 80°C, and then passed through a pair of rubber squeeze rollers, and further dried in an air bath kept at 150°C.
  • the amount of Zn applied to the steel sheet surfaces was 0.75 mg/m 2 .
  • the above treated steel sheet was coated with an MgO slurry, dried, and then subjected to a final annealing under an H 2 atmosphere, wherein the steel sheet was gradually heated at a heating rate of 2.5°C/hr from 800°C to 900°C and successively kept at 1,200°C for 10 hours.
  • Table 15 shows the magnetic properties and grain size of the resulting product steel sheet together with those of a comparative product steel sheet produced by a conventional method.
  • a hot rolled sheet having a thickness of 2.0 mm and having a composition containing C: 0.041 %, Si: 3.29%, Mn: 0.085%, Se: 0.026% andS: 0.029% was annealed at 1,000°C for 1 minute, and then pickled.
  • the pickled sheet was cold rolled into a thickness of 0.60 mm, and the first cold rolled sheet was intermediately annealed at 950°C for 1 minute and then secondly cold rolled into a final gauge of 0.23 mm.
  • the finally cold rolled sheet was subjected to a decarburization annealing at 840°C for 3 minutes under an atmosphere consisting of 50% by volume of H 2 and the remainder being N 2 and having a dew point of 60°C.
  • Table 16 shows the magnetic properties, that is, the iron loss W 17/50 and the magnetic induction B lo , of the resulting grain-oriented silicon steel sheet together with those of a comparative grain-oriented silicon steel sheet produced by using an MgO slurry containing no Bi 2 0 3 according to a conventional method.
  • the crystal grain size of the resulting grain-oriented silicon steel sheet can be effectively made into small size, and a grain-oriented silicon steel sheet having high magnetic induction and low iron loss can be obtained.

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Claims (10)

1. Une méthode de fabrication de feuilles d'acier au silicium à grain orienté, selon laquelle une feuille d'acier au siiicium laminée à chaud contenant au moins un des éléments S, Se et Te en tant qu'inhibiteur pour la croissance de grains de recristallisation primaire, est soumise à au moins un laminage à froid à une phase, la feuille d'acier laminée finie de laminage à froid étant soumise à une opération de recuit de décarbonisation, la feuille d'acier décarbonisée étant ensuite revêtue d'un séparateur de recuit se composant principalement de MgO, puis soumise à une opération de recuit final, la méthode étant caractérisée en ce qu'au moins une ramification, sélectionnée à partir du groupe se composant des éléments Ge, Sn, Pb, As, Bi et Zn, et de combinaisons contenant ces éléments, est appliquée uniformément sur les surfaces de la feuille d'acier laminée finie de laminage à froid avant l'opération de recuit de décarbonisation.
2. Une méthode selon la revendication 1, dans laquelle au moins une ramification sélectionnée à partir du groupe se composant des éléments Ge, Sn, Pb, As, Bi et Zn et de combinaisons contenant ces éléments, est appliquée uniformément sur les surfaces de la feuille d'acier décarbonisée, soit additionnellement, soit exclusivement, avant l'application du séparateur de recuit sur les surfaces de la feuille d'acier.
3. Une méthode selon la revendication 2, dans laquelle la quantité d'au moins une ramification sélectionnée à partir du groupe se composant des éléments Ge, Sn, Pb, As, Bi et Zn, et de combinaisons contenant ces éléments, appliquée sur les deux surfaces de la feuille d'acier, est au minimum de 10 pg/m2, calculée sur la base de l'élément.
4. Une méthode de fabrication de feuilles d'acier au silicium à grain orienté selon la revendication 1, dans laquelle la feuille d'acier laminée finie de laminage à froid est soumise à une opération de recuit préliminaire effectuée à une température se situant dans la gamme de 500-700°C, pendant une durée de 0,5 à 10 minutes, avant l'opération de recuit de décarbonisation.
5. Une méthode selon la revendication 1 ou 4, dans laquelle la quantité d'au moins une ramification sélectionnée à partir du groupe se composant d'éléments de Ge, Sn, Pb, As, Bi et de Zn, et de combinaisons contenant ces éléments, appliquée sur les deux surfaces de la feuille d'acier, est au minimum de 2 pg/m2, cette quantité étant calculée sur la base de l'élément.
6. Une méthode selon la revendication 4, dans laquelle la phase d'application uniforme d'au moins une ramification sélectionnée à partir du groupe se composant d'éléments de Ge, Sn, Pb, As, Bi et Zn, et de combinaisons contenant ces éléments, sur les surfaces de la feuille d'acier, a lieu avant l'opération de recuit primaire.
7. Une méthode selon la revendication 4, dans lequelle la phase consistant à soumettre la feuille laminée finie de laminage à froid à l'opération de recuit préliminaire a lieu avant la phase d'application uniforme d'au moins une ramification sélectionnée à partir du groupe se composant d'éléments de Ge, Sn, Pb, As, Bi et Zn, et de combinaisons contenant ces éléments, sur les surfaces de la feuille d'acier.
8. Une méthode selon la revendication 4, dans laquelle la phase d'application uniforme d'au moins une ramification sélectionnée à partir du groupe se composant d'éléments de Ge, Sn, Pb, As, Bi et Zn, et de combinaisons contenant ces éléments, sur les surfaces de la feuille d'acier laminée finie de laminage à froid a lieu avant et après l'opération de recuit préliminaire.
9. Une méthode de fabrication de feuilles d'acier au silicium à grain orienté, dans laquelle une feuille d'acier au silicium laminée à chaud contenant au moins un des éléments S, Se et Te en tant qu'inhibiteur pour la croissance de grains de recristallisation primaire, est soumise à au moins un laminage à froid à une phase, la feuille d'acier laminée finie de laminage à froid étant soumise à une opération de recuit de décarbonisation, et la feuille d'acier décarbonisée étant ensuite revêtue d'un séparateur de recuit se composant principalement de MgO, puis soumise à une opération de recuit final, la méthode étant caractérisée en ce que le dit séparateur de recuit contient en outre au moins un élément de Bi et des combinaisons contenant du Bi.
10. Une méthode selon la revendication 9, dans laquelle le séparateur de recuit contient de 0,1 à 5,0% en poids, calculé sur la base du Bi, d'au moins un élément de Bi et une des combinaisons contenant du Bi.
EP19850303595 1984-05-24 1985-05-22 Procédé pour la production de tôle en acier au silicium à grain orienté Expired EP0162710B1 (fr)

Applications Claiming Priority (8)

Application Number Priority Date Filing Date Title
JP103696/84 1984-05-24
JP10369684A JPS60248816A (ja) 1984-05-24 1984-05-24 一方向性けい素鋼板の製造方法
JP113790/84 1984-06-05
JP11379084A JPS60258412A (ja) 1984-06-05 1984-06-05 一方向性けい素鋼板の製造方法
JP25580784A JPS61136627A (ja) 1984-12-05 1984-12-05 磁気特性の優れた一方向性けい素鋼板の製造方法
JP255807/84 1984-12-05
JP44940/85 1985-03-08
JP4494085A JPS61204314A (ja) 1985-03-08 1985-03-08 磁気特性のすぐれた一方向性けい素鋼板の製造方法

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US3333992A (en) * 1964-06-29 1967-08-01 Armco Steel Corp Production of oriented silicon-iron using grain growth inhibitor during primary recrystallization heat treatment
US4042425A (en) * 1971-10-11 1977-08-16 Kawasaki Steel Corporation Process of pretreating cold-rolled steel sheet for annealing
JPS5432412B2 (fr) * 1973-10-31 1979-10-15
JPS5178733A (en) * 1974-12-28 1976-07-08 Kawasaki Steel Co Takaijisokumitsudoo jusuruichihokoseidenjikohanno seizohoho
US4171994A (en) * 1975-02-13 1979-10-23 Allegheny Ludlum Industries, Inc. Use of nitrogen-bearing base coatings in the manufacture of high permeability silicon steel
JPS5920745B2 (ja) * 1980-08-27 1984-05-15 川崎製鉄株式会社 鉄損の極めて低い一方向性珪素鋼板とその製造方法
JPS58107417A (ja) * 1981-12-21 1983-06-27 Kawasaki Steel Corp 鉄損のすぐれた一方向性けい素鋼板の製造方法
JPS58151423A (ja) * 1982-03-05 1983-09-08 Kawasaki Steel Corp 磁気特性の優れた一方向性けい素鋼板の製造方法
JPS5931823A (ja) * 1982-08-17 1984-02-21 Kawasaki Steel Corp 磁束密度の高い一方向性珪素鋼板の製造方法

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