US3856568A - Method for forming an insulating film on an oriented silicon steel sheet - Google Patents

Method for forming an insulating film on an oriented silicon steel sheet Download PDF

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US3856568A
US3856568A US00292715A US29271572A US3856568A US 3856568 A US3856568 A US 3856568A US 00292715 A US00292715 A US 00292715A US 29271572 A US29271572 A US 29271572A US 3856568 A US3856568 A US 3856568A
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steel sheet
percent
coating solution
film
oriented silicon
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O Tanaka
T Yamamoto
T Takata
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Nippon Steel Corp
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Nippon Steel Corp
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
    • H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
    • H01F1/147—Alloys characterised by their composition
    • H01F1/14766—Fe-Si based alloys
    • H01F1/14775—Fe-Si based alloys in the form of sheets
    • H01F1/14783—Fe-Si based alloys in the form of sheets with insulating coating
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/68—Temporary coatings or embedding materials applied before or during heat treatment
    • C21D1/70—Temporary coatings or embedding materials applied before or during heat treatment while heating or quenching
    • 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
    • C21D8/1288—Application of a tension-inducing coating
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
    • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
    • C23C22/24—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing hexavalent chromium compounds
    • C23C22/33—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing hexavalent chromium compounds containing also phosphates
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/73—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process
    • C23C22/74—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process for obtaining burned-in conversion coatings

Definitions

  • a method for producing anorientedsilicon steel sheet which a surface-film, which improves iron loss and magnetostriction characteristics of the steel sheet comprising the steps of applying to the surface of the oriented steel sheet a coating solution composed of 4 to 16 wt. percent of colloidal silica, 3 to 24 wt. percent of aluminum phosphate and 0.2 to 4.5 wt. percent of atleast one compound selected from the group consisting of chromic anhydride and chromate with or without the addition of 1 to 5 grams of boric acid and baking the thus applied coating solution at a temperature above 350C.
  • oriented steel sheet used here means a single oriented steel sheet of Fe-Si alloy containing up to 6 percent by weight of Si ormost commonly about 3 percentby weight of Si, having a so-called cube-onedge or a (110) [001] crystal structure as repeated by Miller index obtained by a combination of proper known rolling and heat-treatment of the steel sheet of this composition, in which the rolling direction is magnetically most easy to' magnetize.
  • Orient core Trade Mark of Nippon Steel Corporation
  • Orient core-HI'B Trade Mark of Nippon Steel Corporation
  • the surface film made on an oriented silicon steel sheet consists of a glassy film formed during the high temperature finishing annealing or a phosphate film applied onto the glassy film or directly onto the naked steel sheet having no glassy film.
  • the glassy film is formed by the reaction of magnesia, which is an annealing separating agent, or an oxide added, as required, to the magnesia and a surface oxidized layer of the steel sheet, and consists mostly of magnesium silicate.
  • magnesia which is an annealing separating agent, or an oxide added, as required, to the magnesia and a surface oxidized layer of the steel sheet, and consists mostly of magnesium silicate.
  • the phosphate film is made by applying an aqueous solution of such metallic phosphate as magnesium phosphate or aluminum phosphate to a steel sheet and baking the same.
  • the glassy film has an action effective to the improvement of the iron loss and magnetostriction characteristics.
  • the formation of this film is so easily influenced by the characteristics of magnesia, the state of the surface oxidized layer of the steel sheet, the annealingatmosphere and temperature conditions that it is difficult in fact to obtain a uniform thickness 2 4 and characteristics. Therefore, with only the glassy film, it is insufficient to utilize the effect of the surface film.
  • the phosphate film is low in the effect of the surface film and may even occasionally deteriorate the characteristics to be lower than in case the surface film is made of the glassy film only.
  • An object of the present invention is to provide an oriented electromagnetic steel sheet, on which is formed a surface film serving to improve the iron loss and magneto-striction characteristics.
  • Another object of the present invention is to provide an oriented electromagnetic steel 'sheet, on which is formed a surface film having good adhesive properties.
  • a further object of the present invention is to obtain a uniform surface filmon the above-mentioned steel sheet.
  • the accompanying drawing is a graph showing the difference in the effect on the iron loss between the coating of the present invention and .a conventional magnesium phosphate coating applied to bare oriented steel samples after having removed the surface film formed on the silicon steel sheet products respectively.
  • a surface film formed by applying and baking'a coating solution having colloidal silica as a main component, aluminum phosphate and at least one compound selected from the group consisting of chromic anhydride and chromates as a binder in the fundamental composition has a great effect on the improvement. of the iron loss and magnetostriction characteristics of an oriented silicon steel sheet.
  • An aqueous dispersion of supermicro-granular (for example, of a granule diameter of 10 to 20 mp.) colloidal silica performs a film formation. When the aqueous solution is applied onto a steel sheet and isbaked, a film can be formed.
  • this film has a disadvantage that it is low in the adhesion to the steel sheet. If a mixed aqueous solution of aluminum phosphate and one or more of'chromic anhydride and chromates is added to this aqueous dispersion of colloidal silica, the adhesion of the film can be improved. This is thought to be attributable to the fact that the above-mentioned mixture acts as a binder. Even with aluminum phosphate alone as a binder, the adhesion may be improved but, when the film is long exposed to a wet atmosphere, there occurs a phenomenon that the silica lamina is isolated. In order to prevent this phenomenon, it is effective to add one or more of chromic anhydride and chromates to the solution.
  • this surface film has not only the abovementioned features but also the following features for the oriented silicon steel sheet. Even when thickly applied to, it presents aa beautiful appearance and the adhesion is not impaired thereby. Therefore, a high interlayer resistance and voltage resistance can be easily obtained.
  • the film is also so flat and smooth that, even if it is thickly applied, a practically sufficient space factor can be obtained. Further, the film is so compact that it is high in the heat-proofness, atmosphere-proofness and anticorrosion.
  • the properties and mixing rates of component solutions of the coating solution to be used in the present invention are as follows.
  • Supermicrogranular colloidal silica which is dispersed in water and is a main component of the coating solution is required to obtain a sta ble mutual solubility with an aqueous solution of a phosphate, chromic acid or a chromate as a binder.
  • commercial Snowtex (Trade Mark of Nissan Chemical Industries, Ltd.) (of an SiO content of 20 percent, hydrogen ion concentration (pH) of 3.0 to 4.0 and specific gravity of 1.15 at 20C.) renders a suitable example for the present invention.
  • Aluminum phosphate to be used as a binder may be nearly of a composition of aluminum biphosphate, in which a mixing ratio of A1 0 and H PO is about 0.16 by mols and the proper pH is about 0.9 (about 1.9 as corrected by the concentration) in an aqueous solution of 50 percent. It is needless to say that the present invention is not limited to the above-mentioned values. However, according to experiences, when the pH is low, the solution bubbles and its applicability is reduced. In order to obtain the above-mentioned pH value, the said mol ratio is suitable for the preparation and there is further an advantage that a commercial product can be utilized.
  • the proper mixing ratios of components of the coating solution of the present invention are as follows: 20 to 80 parts by volume of a 50 percent aqueous solution of aluminum phosphate are added to 100 parts by volume of a 20 percent aqueous dispersion of colloidal silica.
  • This mixture corresponds to a coating solution composed of to 16 percent by weight of colloidal silica and 9 to 24 percent by weight of aluminum phosphate (as calculated as aluminum biphosphate here and hereinafter).
  • the aqueous solution of aluminum phosphate is less than parts by volume, there is shown a phenomenon that, after the baking, the adhesion of the above described silica lamina becomes insufficient and,
  • Chromic acid is of chromic anhydride powder.
  • the addition of 1 gram of chromic anhydride powder to cc. of an aqueous dispersion of colloidal silica can present the above described isolation of the silica lamina which is to be caused in the case of adding no chromic anhydride powder.
  • the proper range of the addition of chromic anhydride powder is 3 to 9 grams.
  • more than 5 parts by volume of a 25 percent aqueous solution of magnesium chromate are to be added to 100 parts by volume of colloidal silica. Then, the above-mentioned isolation of the silica lamina may be prevented.
  • the preferable range of the addition of chromate is 10 to 30 parts by volume.
  • the coating solution of the above-mentioned composition corresponds to an aqueous solution of about 8 to 16 percent by weight of colloidalsilica, 7 to 24 percent by weight of aluminum phosphate and 0.4 to 4.5 percent by weight of chromic anhydride or magnesium chromate. Further, as required, in case a thus coated steel sheet is likely to stick during the heat-treatment, for instance, in case the heat-treatment is carried out at a temperature above 800C, it will be effective to add boric acid or supermicro-granular silica.
  • boric acid or 0.25 to 2 grams of such supermicrogranular silica as, for example, commercial Nipsil VN 3 (Trade Mark of Nippon Silica Industrial Co., Ltd.) (of 93 to 94% SiO a granule diameter less than 10 p. and a pH (at 4 percent) of 5.8 to 6.8) to 100 cc. of an aqueous dispersion of colloidal silica.
  • Nipsil VN 3 Trade Mark of Nippon Silica Industrial Co., Ltd.
  • boric acid or supermicrogranular silica is carried out as follows:
  • the thus prepared solution is of a concentration of about 23 to 28 B.
  • the thus prepared solution is of a concentration of about 26 to 31 B.
  • the coating solution of the abovementioned composition is used after adjusted to be of a concentration proper for the objective film deposition amount. That is to say, it is used in the state of the original solution so as to contain 4 to 16 percent by weight of colloidal silica, 3 to 24 percent by weight of aluminum phosphate and 0.2 to 4.5 percent by weight of one or more of chromic anhydride and chromates or as diluted with water.
  • the coating solution of the present invention is uniformly applied onto the surface of the abovementioned oriented silicon steel sheet by dipping or spraying and thereafter is pressed with pressing rolls, or coated by any known method.
  • the coating solution of the present invention can be applied to an oriented silicon steel sheet, irrespective of the surface ofthe oriented silicon steel sheet being covered with a glassy film or with a phosphate film or both films or being bare without covered by them.
  • the coating solution of the present invention is baked after it has been applied to the surface of a steel sheet as above-mentioned.
  • a favorable surface film can be obtained, when it is heated to a temperature above 350+C., preferably a temperature between 400to 900C.
  • the baking temperature range is so wide as above-mentioned.
  • the lower limit of the baking temperature is set at 350C, because, if the coating temperature is below this limit, the reaction of the coating solution is insufficient and the hygroscopicity remains in the formed surface film.
  • the baking temperature may be raised up to a relatively high one, but practically the temperature above 900C. is not economical, and it is even feared that at such a high temperature above 900C. the characteristics of the surface film will be deteriorated depending upon the atmosphere and treating time. Thus, the baking temperature above 900C. is not desirable.
  • the atmosphere at the time of baking may be of air, nitrogen or a mixture of nitrogen and hydrogen.
  • the glassy film on an oriented silicon steel sheet is used to be formed by a high temperature finishing annealing. Then, the excess annealing separating agent is removed by water-washing or light pickling to leave the glassy film on the surface of the steel sheet. Or, for the purpose of improving the punchability, the glassy film may be also'removed by pickling. Then, a so-called heat-flattening is made to remove a coil bent of the steel sheet and to flatten the steel sheet. This heat-treatment is carried out at 800 to 900C. for not more than about 3 minutes.
  • This condition corresponds to the high temperature side of the above-mentioned baking condition. Therefore, if the coating solution is applied before the heat-flattening, the heat-flattening and baking are able to be simultaneously carried out. Further, as in such case, the interlayer resistance and voltage resistance are often impaired by flaws caused by builds-up on hearth rolls, the coating solution may be again applied and baked at, a low temperature in order to remedy the above-mentioned defect. Or, it is also possible to apply the coating solution and baking the same at a low temperature of 400 to 500C. after the heat-flattening.
  • EXAMPLE 1 Samples taken adjacently to one another from the same commercial coil of an oriented silicon steel sheet of a thickness of 0.30 mm. were treated with a mixed acid of sulfuric acid and hydrofluoric acid to remove the surface films an'd were then continuously annealed at 800C. in hydrogen for 3 minutes to remove stains. Thus,'the samples for the test have been prepared. To these samples there were applied a phosphate coating solution of magnesium phosphate and a coating solution of a composition of cc of a 20 percent aqueous dispersion of colloidal silica, 60 cc.
  • the Figure shows the results of the measurements of iron losses /50 and W 17/50 before and after forming films of respective coatings.
  • the reduction in iron loss obtained by the coating solution of the present invention is very large.
  • Table 1 indicates the results of the measurements of the magnetostriction characteristics.
  • the sample by the coating solution of the present invention is low in the magnetostriction and is also low in the deterioration to be caused by the compressive force.
  • Example 2 Samples taken adjacently to one another from the same coil of an oriented silicon steel sheet of a thickness of 0.30 mm., as finished annealed at a high temperature, were subjected to water-washing and light pickling to remove an annealing separating agent remained on the surfaces of the samples and to leave the glassy films and were then annealed to remove coil bents and strains. Thus, the samples for the test were prepared. To these samples covered with the glassy films there were applied a phosphate coating solution of magnesium phosphate and a coating solution of 100 cc. of a percent aqueous dispersion of colloidal silica,'60 cc.
  • Example 2 of a 50 percent aqueous solution of aluminum phosphate, 6 grams of chrornic anhydride and 0.75 gram of supermicrogranular silica of the present invention respectively in the same manner as in Example 1 and were thereafter baked at 850C. for 10 seconds in air in a continuous oven.
  • Table 2 shows the results measured in the same manner as in Example 1 before applying the coating and after applying and baking it. The effect of the surface filmby the coating solution of the present invention is large.
  • Table 3 there are shown characteristics of the surface film samples by the coating solution of the present invention after subjected to a strain-removing annealing at 800C. for 4 hours in a dry atmosphere of 10% H and N The effect of the surface film is not lost even by the heat-treatment of a long time.
  • Table 4 shows the results of measuring the coating deposition, interlayer resistance and-space factor of' these surface films.
  • the surface film of the present invention is high in the interlayer resistance and is very small particularly in the reduction in resistance to be caused by the annealing in a reducing atmosphere. Though it is high in the coating deposition, it keeps a high space factor.
  • EXAMPLE 3 1 Samples were prepared-in the same manner as in Example 2. A coating solution of a composition of 100 cc. of a 20 percent aqueous solution of colloidal silica, 60 cc. ofa 50 percent aqueous solution of aluminum phosphate, cc. of a 25 percent aqueous solution of magnesium chromate and 0.75 gram of supermicrogranular silica of the present invention was applied to these samples having glassy films andwas baked at about 450C. for 10 seconds in an open oven. These samples were further continuously annealed to remove strains at 810C. for 2 minutes in a nitrogen atmosphere.
  • Table 5 shows the results measured in the same manher as in Example 1 before and after the strainremoving annealing.
  • the improvements of the iron loss and magnetostriction characteristics after the annealing are large, showing the better characteristics than in the case of the glassy film only mentioned also in the same table. This shows that, even when the coating solution of the present invention is baked at a low temperature, a sufficient effect of the surface film can be obtained by a subsequent annealing at a high temperature.
  • EXAMPLE 4 After the treatment in Example 2, a coating solution of 100 cc.'of a 20 percent aqueous dispersion of colloidal silica, 60 cc. of a 50 percent aqueous solution of aluminum phosphate and 15 cc. of a percent aque 1 B7 .0 l .9 1 1 .1 50.0 I 33 .3 3 .7
  • the original solution was of about 25 Be
  • water to be of about 15 Be was applied to the steel sheet and was baked at 400C. for 10 seconds in an open oven.
  • the obtained surface film was flat, smooth and uniform.
  • the coating solution of the present invention can be used also for improving the interlayer resistance and voltage resistance and further for recoating for the purpose of securing the insulation of the part, after a protrusion thereof has been removed by shearing or slitting.
  • a method for forming an insulating film on an oriented silicon steel sheet comprising the steps of applying to the oriented silicon steel sheet a' coating solution composed of 4 to 16 wt. percent of colloidal silica, 3 to 24 wt. percent of aluminum phosphate, calculated as aluminum biphosphate, and 0.2 to 4.5 wt. percent of at least one compound selected from the group consisting of chromic anhydride and chromate and baking the thus applied coating solution at a temperature above 2.
  • the method according to claim 1 in which boric acid is added to the coating solution in an amount of 1 to 5 grams per cc. of a water dispersion of colloidal magnetostriction characteristic of the steel sheet, comprising the steps of forming a glassy film.
  • a coating solution composed of 4 to 16 wt. percent of colloidal silica; 3 to 24 wt. percent of aluminum phosphate, calculated as aluminum biphosphate, and 0.2 to 4.5 wt. percent of at least one compound selected from the group consisting of chromic anhydride and chromate. baking the thus applied coating solution at a temperature above 350C and then subjecting the magneto-striction characteristics of the steel sheet, ac

Abstract

A method for producing an oriented silicon steel sheet which a surface film, which improves iron loss and magnetostriction characteristics of the steel sheet, comprising the steps of applying to the surface of the oriented steel sheet a coating solution composed of 4 to 16 wt. percent of colloidal silica, 3 to 24 wt. percent of aluminum phosphate and 0.2 to 4.5 wt. percent of at least one compound selected from the group consisting of chromic anhydride and chromate with or without the addition of 1 to 5 grams of boric acid and baking the thus applied coating solution at a temperature above 350*C.

Description

Tanaka et a1.
1 11- 3,856,568 [451 Dec. 24, 1974 METHOD FOR FORMING AN INSULATING FILM ON AN ORIENTED SILICON STEEL SHEET Inventors: Osamu Tanaka; Takaaki Yamamoto; Toshihiko Takata, all of Kitakyushu, Japan Nippon Steel Corporation, Tokyo, Japan Filed: Sept. 27, 1972 Appl. No.: 292,715
Assignee:
Foreign Application Priority Data Sept. 27,1971 Japan 46-75233 11.8. C1. 117/70 B, 117/70 C, 117/129, 117/l35.1, 117/234", 148/6.16, 148/12, 336/218 Int. Cl. C220 39/46, HOlf 27/24 Field of Search..... 117/129, 70 C, 70 B, 1351,
References Cited I UNITED STATES PATENTS 8/1951 Thompson ..1 148/6 .l6
THE PRESENT INVENTION COATING OF MAGNESIUM 3,150,015 9/1964 Boyer et a1. l17/l35.1 X 3,207,636 9/1965 Wada et'al l48/6.l6 3,522,108 7/1970 Yamamoto et al. 117/70 C X 3,522,113 7/1970 3,528,863 9/1970 3,533,861 12/1970 Foster et a1 117/129 X 3,670,278 6/1972 Foster et a1 117/129 X Primary Examiner-Ralph Husack Attorney, Agent, or FirmWenderoth, Lind & Ponack ABSTRACT A method for producing anorientedsilicon steel sheet which a surface-film, which improves iron loss and magnetostriction characteristics of the steel sheet, comprising the steps of applying to the surface of the oriented steel sheet a coating solution composed of 4 to 16 wt. percent of colloidal silica, 3 to 24 wt. percent of aluminum phosphate and 0.2 to 4.5 wt. percent of atleast one compound selected from the group consisting of chromic anhydride and chromate with or without the addition of 1 to 5 grams of boric acid and baking the thus applied coating solution at a temperature above 350C.
5 Claims, 1 Drawing Figure COATING ACCORDING TO 450 IS/5o PHOSPHATE 4 1.3 W 6 17 A 0 /50 A o/ 1 5 1 /A 0 z A Z o 1 K O 1- 1 9' 1 1 o o 0 LI 0 t: L! o I ,6
1.0- WIS/5O Ll. t 4, A a O O-9 .o J /A g A /t O: l
IRON LOSS BEFORE THE COATING tw/K PAIENTEI] DEC 2 4 I974 IRO LOSS AFTER THE COATING (IN/K FI-I OSPHATE I7/ A y I I I I I I 0,9 LO I.I L2 L3 IRON LOSS BEFORE THE COATING Iw/x METHOD FOR FORMING AN INSULATING FILM ON AN ORIENTED SILICON STEEL SHEET This invention relates to the production of an oriented silicon steel sheet having a surface film which improves the iron loss and magnetostriction characteristics of the direction silicon steel sheet.
It has been recognized since long ago that the magnetostriction of an oriented silicon steel sheet is one of the main causes of the noise of a transformer. made of this steel sheet. Reducing the magnetostriction oscillation induced by the magnetostriction is important to subdue the noise of the transformer, and the surface film formed on the steel sheet is known as an industrially effective means to this purpose. The action of this surface film is caused by the tension exerted by the surface film on the steel sheet, because in the magnetization of the oriented silicon steel sheet under this tensionthe magnetization process, which does not take part in the magnetostriction, that is, that which is caused by the movement of the magnetic wall by 180, becomes dominant. This is explained from the view point of the magnetic section theory. The tension exerted by the surface film on the steel sheet is produced during the steel sheet being cooled in the heat treatment due to the difference in the thermal expansion coefficient between the steel sheet and the surface film.
" Further, the tension of the surface film on the steel sheet is effective also to the improvement of the iron loss of the oriented silicon steel sheet. It has been discovered by one of the present inventors that particularly the more complete the orientation, the higher the effect [see Jr. 'Appl. Phys, 41, 2981 (1970)]. v
The term oriented steel sheet used here means a single oriented steel sheet of Fe-Si alloy containing up to 6 percent by weight of Si ormost commonly about 3 percentby weight of Si, having a so-called cube-onedge or a (110) [001] crystal structure as repeated by Miller index obtained by a combination of proper known rolling and heat-treatment of the steel sheet of this composition, in which the rolling direction is magnetically most easy to' magnetize. There are marketed, for instance, under the trade marks of Orient core (Trade Mark of Nippon Steel Corporation) or Orient core-HI'B" (Trade Mark of Nippon Steel Corporation), which hasmore complete orientation than before (see U.S. Pat. Nos; 3,159,511 and 3,287,183).
It is usual that the surface film made on an oriented silicon steel sheet consists of a glassy film formed during the high temperature finishing annealing or a phosphate film applied onto the glassy film or directly onto the naked steel sheet having no glassy film.
The glassy film is formed by the reaction of magnesia, which is an annealing separating agent, or an oxide added, as required, to the magnesia and a surface oxidized layer of the steel sheet, and consists mostly of magnesium silicate. The phosphate film is made by applying an aqueous solution of such metallic phosphate as magnesium phosphate or aluminum phosphate to a steel sheet and baking the same.
it has been found that among the above-mentioned surface films the glassy film has an action effective to the improvement of the iron loss and magnetostriction characteristics. However, the formation of this film is so easily influenced by the characteristics of magnesia, the state of the surface oxidized layer of the steel sheet, the annealingatmosphere and temperature conditions that it is difficult in fact to obtain a uniform thickness 2 4 and characteristics. Therefore, with only the glassy film, it is insufficient to utilize the effect of the surface film. On the other hand, the phosphate film is low in the effect of the surface film and may even occasionally deteriorate the characteristics to be lower than in case the surface film is made of the glassy film only.
There have been suggested various methods for developing the effect of the surface film more than ever. For example, in Japanese Patent Publication No. 32815/1970 (U.S. Pat. No. 3,522,l 13), there was formed a potassium silicate glass film on a silicon steel sheet covered with a glassy film and/or phosphate coating film. In Japanese Patent Publication No. 18605/1971 (U.S. Pat. No. 3,528,863), a glass suspension made by crushing a glass frit lower in the thermal expansion coefficient than the silicon steel is applied and baked on a complex compound having magnesium as a substrate. Further, a method, wherein a glass frit is ceramic-coated in the same manner as in the latter, is suggested in British Pat. No. 1,077,377.
An object of the present invention is to provide an oriented electromagnetic steel sheet, on which is formed a surface film serving to improve the iron loss and magneto-striction characteristics.
} Another object of the present invention is to provide an oriented electromagnetic steel 'sheet, on which is formed a surface film having good adhesive properties.
A further object of the present invention is to obtain a uniform surface filmon the above-mentioned steel sheet.
Other objects will become clear from the below described matters and accompanying drawing.
The accompanying drawing is a graph showing the difference in the effect on the iron loss between the coating of the present invention and .a conventional magnesium phosphate coating applied to bare oriented steel samples after having removed the surface film formed on the silicon steel sheet products respectively.
It has been discovered by the present inventors that a surface film formed by applying and baking'a coating solution having colloidal silica as a main component, aluminum phosphate and at least one compound selected from the group consisting of chromic anhydride and chromates as a binder in the fundamental composition has a great effect on the improvement. of the iron loss and magnetostriction characteristics of an oriented silicon steel sheet. An aqueous dispersion of supermicro-granular (for example, of a granule diameter of 10 to 20 mp.) colloidal silica performs a film formation. When the aqueous solution is applied onto a steel sheet and isbaked, a film can be formed. However, this film has a disadvantage that it is low in the adhesion to the steel sheet. If a mixed aqueous solution of aluminum phosphate and one or more of'chromic anhydride and chromates is added to this aqueous dispersion of colloidal silica, the adhesion of the film can be improved. This is thought to be attributable to the fact that the above-mentioned mixture acts as a binder. Even with aluminum phosphate alone as a binder, the adhesion may be improved but, when the film is long exposed to a wet atmosphere, there occurs a phenomenon that the silica lamina is isolated. In order to prevent this phenomenon, it is effective to add one or more of chromic anhydride and chromates to the solution.
The reason, why the effects of improving iron loss and magnetostriction characteristics of an oriented silicon steel sheet, obtained by a surface film composed of colloidal silica as a main component of the coating solution of the present invention become very high, as shown in the later described examples, resides in the following facts, that is, due to the low thermal expan sion coefficient of silica in general the surface film composed of colloidal silica as a main component is also solow in the thermal expansion coefficient that the tension exerted by the surface film on the steel sheet is high, and further due to a characteristic action of supermicrogranular colloidal silica of filling minor defects of the surface any unevenness of the glass film can be corrected.
Further, this surface film has not only the abovementioned features but also the following features for the oriented silicon steel sheet. Even when thickly applied to, it presents aa beautiful appearance and the adhesion is not impaired thereby. Therefore, a high interlayer resistance and voltage resistance can be easily obtained. The film is also so flat and smooth that, even if it is thickly applied, a practically sufficient space factor can be obtained. Further, the film is so compact that it is high in the heat-proofness, atmosphere-proofness and anticorrosion. These additional features make the effects of improving the iron loss and magnetostriction characteristics of the surface film of the present invention more positive.
In the following a surface film of the present invention and a method of applying it to the production of oriented silicon steels shall be explained in detail.
The properties and mixing rates of component solutions of the coating solution to be used in the present invention are as follows. Supermicrogranular colloidal silica which is dispersed in water and is a main component of the coating solution is required to obtain a sta ble mutual solubility with an aqueous solution of a phosphate, chromic acid or a chromate as a binder. For instance, commercial Snowtex (Trade Mark of Nissan Chemical Industries, Ltd.) (of an SiO content of 20 percent, hydrogen ion concentration (pH) of 3.0 to 4.0 and specific gravity of 1.15 at 20C.) renders a suitable example for the present invention. Aluminum phosphate to be used as a binder may be nearly of a composition of aluminum biphosphate, in which a mixing ratio of A1 0 and H PO is about 0.16 by mols and the proper pH is about 0.9 (about 1.9 as corrected by the concentration) in an aqueous solution of 50 percent. It is needless to say that the present invention is not limited to the above-mentioned values. However, according to experiences, when the pH is low, the solution bubbles and its applicability is reduced. In order to obtain the above-mentioned pH value, the said mol ratio is suitable for the preparation and there is further an advantage that a commercial product can be utilized.
The proper mixing ratios of components of the coating solution of the present invention are as follows: 20 to 80 parts by volume of a 50 percent aqueous solution of aluminum phosphate are added to 100 parts by volume of a 20 percent aqueous dispersion of colloidal silica. This mixture corresponds to a coating solution composed of to 16 percent by weight of colloidal silica and 9 to 24 percent by weight of aluminum phosphate (as calculated as aluminum biphosphate here and hereinafter). 'Ifthe aqueous solution of aluminum phosphate is less than parts by volume, there is shown a phenomenon that, after the baking, the adhesion of the above described silica lamina becomes insufficient and,
if it is more than parts by volume, after the baking, the film becomes turbid to be white and shows a bad appearance. Chromic acid is of chromic anhydride powder. The addition of 1 gram of chromic anhydride powder to cc. of an aqueous dispersion of colloidal silica can present the above described isolation of the silica lamina which is to be caused in the case of adding no chromic anhydride powder. The proper range of the addition of chromic anhydride powder is 3 to 9 grams. In the case of adding chromate, for instance, more than 5 parts by volume of a 25 percent aqueous solution of magnesium chromate are to be added to 100 parts by volume of colloidal silica. Then, the above-mentioned isolation of the silica lamina may be prevented. The preferable range of the addition of chromate is 10 to 30 parts by volume.
The coating solution of the above-mentioned compositioncorresponds to an aqueous solution of about 8 to 16 percent by weight of colloidalsilica, 7 to 24 percent by weight of aluminum phosphate and 0.4 to 4.5 percent by weight of chromic anhydride or magnesium chromate. Further, as required, in case a thus coated steel sheet is likely to stick during the heat-treatment, for instance, in case the heat-treatment is carried out at a temperature above 800C, it will be effective to add boric acid or supermicro-granular silica. It is proper to add 1 to 5 grams of boric acid or 0.25 to 2 grams of such supermicrogranular silica as, for example, commercial Nipsil VN 3 (Trade Mark of Nippon Silica Industrial Co., Ltd.) (of 93 to 94% SiO a granule diameter less than 10 p. and a pH (at 4 percent) of 5.8 to 6.8) to 100 cc. of an aqueous dispersion of colloidal silica.
The addition of boric acid or supermicrogranular silica is carried out as follows:
A. Case of adding boric acid For example, in the mixing rates of 100 cc. of an I aqueous dispersion of colloidal silica,'60 cc. of an aqueous solution of aluminum phosphate, 6 grams of chromic anhydride and 2 grams of boric acid:
i. 2 kg. of boric acid are put into 15 liters of warm water above 60C. and are well stirred to be dissolved. (This shall be a solution A.)
ii. 6 kg. of chromic anhydride are added to 60 liters of an aqueous solution of 50 percent aluminum phosphate and are well stirred to be dissolved and then 100 liters of an aqueous dispersion of colloidal silica are added to the solution. (This shall be a solution B.)
iii. The solutions A and B are mixed and stirred.
The thus prepared solution is of a concentration of about 23 to 28 B.
B. Case of adding supermicrogranular silica For example, in the case of the mixing rates of 100 cc. of an aqueous dispersion of colloidal silica, 60 cc.
of an aqueous solution of aluminum phosphate, 6
grams of chromic anhydride and 0.5 gram of supermicrogranular silica:
6 kg. of chromic anhydride are added to 60 liters of a 50% aqueous solution of aluminum phosphate and are well stirred to be dissolved and then 100 liters of an aqueous dispersion of colloidal silica and 0.5 kg. of supermicrogranular silica are added and stirred.
The thus prepared solution is of a concentration of about 26 to 31 B.
In applying the coating solution of the abovementioned composition to an oriented silicon steel sheet, it is used after adjusted to be of a concentration proper for the objective film deposition amount. That is to say, it is used in the state of the original solution so as to contain 4 to 16 percent by weight of colloidal silica, 3 to 24 percent by weight of aluminum phosphate and 0.2 to 4.5 percent by weight of one or more of chromic anhydride and chromates or as diluted with water.
The coating solution of the present invention is uniformly applied onto the surface of the abovementioned oriented silicon steel sheet by dipping or spraying and thereafter is pressed with pressing rolls, or coated by any known method.
The coating solution of the present invention can be applied to an oriented silicon steel sheet, irrespective of the surface ofthe oriented silicon steel sheet being covered with a glassy film or with a phosphate film or both films or being bare without covered by them.
However, when applying the coating solution of the present invention no phosphate is required. Phosphate film is not only uneconomic, but rather deteriorates the properties inherent to the coating'of the present invention, excepting a special case of thinly applying the coating solution of the present invention for the purpose of supplying a deficiency of the phosphate film. Such an oriented silicon steel sheet having a bare surface is often produced in order to improve the punchability.'lt is known, however, that in such a case particularly magnetostriction characteristics of the steel sheet are remarkably deteriorated on account of the surface having no coating. When the coating of the present invention is applied to such steel sheet, the magnetostriction characteristics can be improved substantially to those of the case of being covered with a glassy film alone, as'will be seen from the later described examples.
The coating solution of the present invention is baked after it has been applied to the surface of a steel sheet as above-mentioned. A favorable surface film can be obtained, when it is heated to a temperature above 350+C., preferably a temperature between 400to 900C. It is a great advantage of the coating solution of the present invention that the baking temperature range is so wide as above-mentioned. On account of this the baking treatment can be carried out by various methods according to the object to be obtained. The lower limit of the baking temperature is set at 350C, because, if the coating temperature is below this limit, the reaction of the coating solution is insufficient and the hygroscopicity remains in the formed surface film. As to the upper limit it is to note that the baking temperature may be raised up to a relatively high one, but practically the temperature above 900C. is not economical, and it is even feared that at such a high temperature above 900C. the characteristics of the surface film will be deteriorated depending upon the atmosphere and treating time. Thus, the baking temperature above 900C. is not desirable.
The atmosphere at the time of baking may be of air, nitrogen or a mixture of nitrogen and hydrogen.
It has been found that, when the baking is carried out on the high temperature side of the above-mentioned temperature range or even in case it is carried out at a low temperature, if a strain-removing annealing is further carried out continuously or by batch at about 800C. as carried out by an ordinary consumer, the effects of improving the iron loss and magnetostriction characteristics of the surface film of the present invention can be increased. From the fact that the tension of the surface film on the steel sheet is caused by the difference in the thermal expansion coefficient, it is naturally presumed to be effective to bake it at a high temperature. Further, in the case of the baking being carried out at low temperature, it is thought that a surface film effective to the tension may be re-formed in the later high temperature treatment.
ln the production of an oriented silicon steel sheet, it is economical to continuously carry out the step of forming a surface film from the coating solution of the present invention in combination with other steps, Generally, the glassy film on an oriented silicon steel sheet is used to be formed by a high temperature finishing annealing. Then, the excess annealing separating agent is removed by water-washing or light pickling to leave the glassy film on the surface of the steel sheet. Or, for the purpose of improving the punchability, the glassy film may be also'removed by pickling. Then, a so-called heat-flattening is made to remove a coil bent of the steel sheet and to flatten the steel sheet. This heat-treatment is carried out at 800 to 900C. for not more than about 3 minutes. This condition corresponds to the high temperature side of the above-mentioned baking condition. Therefore, if the coating solution is applied before the heat-flattening, the heat-flattening and baking are able to be simultaneously carried out. Further, as in such case, the interlayer resistance and voltage resistance are often impaired by flaws caused by builds-up on hearth rolls, the coating solution may be again applied and baked at, a low temperature in order to remedy the above-mentioned defect. Or, it is also possible to apply the coating solution and baking the same at a low temperature of 400 to 500C. after the heat-flattening. In such case, a sufficient interlayer resistance and voltage resistance can be easily obtained, but, in order to more sufficiently develop the effects of improving the iron loss and magnetostriction characteristics by the surface film, it is necessary to anneal the f lm at about 800C. continuously or by batch by a consumer or manufacturer.
The above-mentioned respective steps can be carried out continuously on one continuous line but, needless to say, may be carried out on separate lines as divided into any number of steps.
Examples of the present invention are shown in the following:
EXAMPLE 1 Samples taken adjacently to one another from the same commercial coil of an oriented silicon steel sheet of a thickness of 0.30 mm. were treated with a mixed acid of sulfuric acid and hydrofluoric acid to remove the surface films an'd were then continuously annealed at 800C. in hydrogen for 3 minutes to remove stains. Thus,'the samples for the test have been prepared. To these samples there were applied a phosphate coating solution of magnesium phosphate and a coating solution of a composition of cc of a 20 percent aqueous dispersion of colloidal silica, 60 cc. of an 50 percent aqueous solution of aluminum phosphate, 6 grams of chromic anhydride and 2 grams of boric acid of the present invention respectively, and were then baked at 800C. for 15 seconds in a nitrogen atmosphere in a continuous oven so that the coating deposition might be 4 gr./m on one surface. The magnetic properties and magnetostriction characteristics were measured with a single plate measuring device before applying the coating and after having applied and baking it. The sample was of a length (in the rolling direction) of 50 cm. and a width of cm. 1
The Figure shows the results of the measurements of iron losses /50 and W 17/50 before and after forming films of respective coatings. The reduction in iron loss obtained by the coating solution of the present invention is very large. 1 Table 1 indicates the results of the measurements of the magnetostriction characteristics. The sample by the coating solution of the present invention is low in the magnetostriction and is also low in the deterioration to be caused by the compressive force.
The above-mentioned results demonstrate that the effects of improving the iron loss and magnetostriction characteristics of the surface film by the coating solution of the present invention are large.
Table 1 Samples Magnetic Magnetostriction Magnetostriction permeability (X 10 (X 10 at 17 kg. at 10 Oe under compression 17 kg. 19 kg. of 30 kgJcm Before applying the coating:
After applying and baking the coating of the present invention:
Before applying the coating:
After applying and baking magnesium phosphate coating;
Example 2 Samples taken adjacently to one another from the same coil of an oriented silicon steel sheet of a thickness of 0.30 mm., as finished annealed at a high temperature, were subjected to water-washing and light pickling to remove an annealing separating agent remained on the surfaces of the samples and to leave the glassy films and were then annealed to remove coil bents and strains. Thus, the samples for the test were prepared. To these samples covered with the glassy films there were applied a phosphate coating solution of magnesium phosphate and a coating solution of 100 cc. of a percent aqueous dispersion of colloidal silica,'60 cc. of a 50 percent aqueous solution of aluminum phosphate, 6 grams of chrornic anhydride and 0.75 gram of supermicrogranular silica of the present invention respectively in the same manner as in Example 1 and were thereafter baked at 850C. for 10 seconds in air in a continuous oven.
Table 2 shows the results measured in the same manner as in Example 1 before applying the coating and after applying and baking it. The effect of the surface filmby the coating solution of the present invention is large.
In Table 3 there are shown characteristics of the surface film samples by the coating solution of the present invention after subjected to a strain-removing annealing at 800C. for 4 hours in a dry atmosphere of 10% H and N The effect of the surface film is not lost even by the heat-treatment of a long time.
Table 2 Sam- Magnetic .lron loss (/kg.) Mugnetostriction ples permeability (X 10") at 10 Oe W 15/50 17/50 17 kg. 19 kg.
1n the case of glassy film only:
1 1913 0.850 1.155 0.7.6 +1.82 2 1921 0.843 1.150 0.13 +1.69 3 1916 0.833 1.131 0.39 +1.43 After applying and baking the coating of the present invention:
1 1916 0.803 1.082 0.52 +0.78 2 1924 0.793 1.075 0.39 +0.52 3 1920 0.803 1.086 -0.59 +0.65 1n the case of glassy film only:
4 1930 0.870 1.203 0.13 +1.95 5 1927 0.850 1.139 -0.26 +1.56 6 1927 0.828 1.106 0.39 +1.30 After applying and baking magnesium phosphate coating:
Table 3 After annealing in 10% H and 90% N at 800C. for 4 hours Sam- Magnetic lron loss ('lkg.) Magnetostriction ples permeability (X 10") at 10 0e -"'15/50 "'17/50 17 kg. 19 kg.
After applying and baking the coating of the'present invention:
1 1919 0.803 11085 -0.52 +0.71 2 1925 0.795 11075 0.39 +0.52 3 1923 0.802 11084 0.59 +0.59 After applying and baking magnesium phosphate coating:
Table 4 shows the results of measuring the coating deposition, interlayer resistance and-space factor of' these surface films. The surface film of the present invention is high in the interlayer resistance and is very small particularly in the reduction in resistance to be caused by the annealing in a reducing atmosphere. Though it is high in the coating deposition, it keeps a high space factor.
These results show that the surface film of the present invention is very smooth and compact.
Table 4 Distribution of interlayer resistance Samples Deposition Space Just after coating:
After annealing in 10% H and 90% N at; 800C. for 4 hours (Q-cm ./sheet) 4.9 .O-9 .9 .0-19 .9 20 .O-49 .9 5O .O-99 .9 100- Coating of the present invention:
Magnesium phosphate coating:
EXAMPLE 3 1 Samples were prepared-in the same manner as in Example 2. A coating solution of a composition of 100 cc. of a 20 percent aqueous solution of colloidal silica, 60 cc. ofa 50 percent aqueous solution of aluminum phosphate, cc. of a 25 percent aqueous solution of magnesium chromate and 0.75 gram of supermicrogranular silica of the present invention was applied to these samples having glassy films andwas baked at about 450C. for 10 seconds in an open oven. These samples were further continuously annealed to remove strains at 810C. for 2 minutes in a nitrogen atmosphere.
Table 5 shows the results measured in the same manher as in Example 1 before and after the strainremoving annealing. The improvements of the iron loss and magnetostriction characteristics after the annealing are large, showing the better characteristics than in the case of the glassy film only mentioned also in the same table. This shows that, even when the coating solution of the present invention is baked at a low temperature, a sufficient effect of the surface film can be obtained by a subsequent annealing at a high temperature.
Table 5 Sam- Magnetic lron loss /kg.) Magnetostriction ples permeability (X 10') at 10 0e 15/50 17/50 17 kg. 19 kg.
1n the case of glassy film only:
1 1946 0.809 1.099 -0.13 +1.30 2 1911 0.843 1.158 0.26 +2.08 I 3 1926 0.800 1.099 0.26 +1.82 Afterapplying the coating of the present invention and baking it at a low temperature:
1 1945 0.812 1.102 +0.13 +1.56 2 1911 0.845 1160 +0.26 +2.21 3 1925 0.803 1.101 +0.19 +2.08 After continuous annealing in N at 810C. for 2 minutes: 1 1947 0.780 1.046 0.52 +0.52 2 1913 0.815 1.108- 0.65 +0.78 3 1929 0.778 1.056 0.52 +0.59
EXAMPLE 4 After the treatment in Example 2, a coating solution of 100 cc.'of a 20 percent aqueous dispersion of colloidal silica, 60 cc. of a 50 percent aqueous solution of aluminum phosphate and 15 cc. of a percent aque 1 B7 .0 l .9 1 1 .1 50.0 I 33 .3 3 .7
ous solution of magnesium chromate of the present invention (the original solution was of about 25 Be) as diluted with water to be of about 15 Be was applied to the steel sheet and was baked at 400C. for 10 seconds in an open oven. The obtained surface film was flat, smooth and uniform.
This shows that the coating solution of the present invention can be used also for improving the interlayer resistance and voltage resistance and further for recoating for the purpose of securing the insulation of the part, after a protrusion thereof has been removed by shearing or slitting.
What is'claimed is:
1. A method for forming an insulating film on an oriented silicon steel sheet, comprising the steps of applying to the oriented silicon steel sheet a' coating solution composed of 4 to 16 wt. percent of colloidal silica, 3 to 24 wt. percent of aluminum phosphate, calculated as aluminum biphosphate, and 0.2 to 4.5 wt. percent of at least one compound selected from the group consisting of chromic anhydride and chromate and baking the thus applied coating solution at a temperature above 2. The method according to claim 1, in which boric acid is added to the coating solution in an amount of 1 to 5 grams per cc. of a water dispersion of colloidal magnetostriction characteristic of the steel sheet, comprising the steps of forming a glassy film. on the oriented silicon steelsheet by a reaction with an annealing separating agent during a high temperature finishing annealing of said steel sheet, thereupon applying to this glassy film a coating solution composed of 4 to 16 wt. percent of colloidal silica; 3 to 24 wt. percent of aluminum phosphate, calculated as aluminum biphosphate, and 0.2 to 4.5 wt. percent of at least one compound selected from the group consisting of chromic anhydride and chromate. baking the thus applied coating solution at a temperature above 350C and then subjecting the magneto-striction characteristics of the steel sheet, ac
cording to claim 4, in which the glassy film formed on the surface of the steel sheet during the high temperature finishing annealing is removed by a pickling and then the coating solution is applied to the surface of the steel sheet.

Claims (5)

1. A METHOD FOR FORMING AN INSULATING FILM ON AN ORIENTED SILICON STEEL SHEET COMPRISING THE STEPS OF APPLYING TO THE ORIENTED SILCON STEEL SHEET A COATING SOLUTION COMPOSED OF 4 TO 16 WT. PERCENT OF COLLOIDAL SILICA, 3 TO 24 WT. PERCENT OF ALUMINUM PHOSPHATE, CALCULATED AS ALUMINUM BIPHOSPHATE AND 0.2 TO 4.5 WT. PERCENT OF AT LEAST ONE COMPOUND SELECTED FROM THE GROUP CONSISTING OF CHROMIC ANHYDRIDE AND CHROMATE
2. The method according to claim 1, in which boric acid is added to the coating solution in an amount of 1 to 5 grams per 100 cc. of a water dispersion of colloidal silica.
3. The method according to claim 1, in which supermicrogranular silica is added to the coating solution in an amount of 0.25 to 2 grams per 100 cc. of a water dispersion of colloidal silica.
4. A method for producing an oriented silicon steel sheet with a surface film which improves iron loss and magnetostriction characteristic of the steel sheet, comprising the steps of forming a glassy film on the oriented silicon steel sheet by a reaction with an annealing separating agent during a high temperature finishing annealing of said steel sheet, thereupon applying to this glassy film a coating solution composed of 4 to 16 wt. percent of colloidal silica, 3 to 24 wt. percent of aluminum phosphate, calculated as aluminum biphosphate, and 0.2 to 4.5 wt. percent of at least one compound selected from the group consisting of chromic anhydride and chromate, baking the thus applied coating solution at a temperature above 350*C and then subjecting the steel sheet to a heat-treatment in a temperature range of from 800* to 900*C after or during the said application of the coating solution and baking thereof.
5. The method for producing an oriented silicon steel sheet with a surface film which improves iron loss and magneto-striction characteristics of the steel sheet, according to claim 4, in which the glassy film formed on the surface of the steel sheet during the high temperature finishing annealing is removed by a pickling and then the coating solution is applied to the surface of the steel sheet.
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3948786A (en) * 1974-10-11 1976-04-06 Armco Steel Corporation Insulative coating for electrical steels
JPS51105771A (en) * 1975-03-14 1976-09-18 Nippon Telegraph & Telephone FUOTOETSU CHINGUHOHO
US4032366A (en) * 1975-05-23 1977-06-28 Allegheny Ludlum Industries, Inc. Grain-oriented silicon steel and processing therefor
IT1115840B (en) * 1977-03-09 1986-02-10 Centro Speriment Metallurg SOLUTION OF COATINGS FOR STEELS FOR MAGNETIC USE
JPS5328043A (en) * 1977-07-09 1978-03-15 Nippon Steel Corp Process for forming insulating coating on directional silicon steel
JPS5567134A (en) * 1978-11-14 1980-05-21 Akai Electric Co Ltd Method for manufacturing electrode of semiconductor device
JPS5655574A (en) * 1979-10-15 1981-05-16 Nippon Steel Corp Manufacture of nondirectional magnetic steel sheet excellent in iron loss and magnetostriction characteristic
US4347085A (en) * 1981-04-23 1982-08-31 Armco Inc. Insulative coatings for electrical steels
JPS60184685A (en) * 1984-03-03 1985-09-20 Nippon Steel Corp Insulating film excellent in heat resistance and slip characteristic for oriented electrical steel sheet
CA1278985C (en) * 1985-04-30 1991-01-15 Allegheny Ludlum Corporation Grain-oriented silicon steel and stress coating therefor
JPH0744097B2 (en) * 1986-10-30 1995-05-15 新日本製鐵株式会社 Method for forming insulating film for electromagnetic steel sheet without seizing of steel sheet during stress relief annealing
US4881975A (en) * 1986-12-23 1989-11-21 Albright & Wilson Limited Products for treating surfaces
US4968361A (en) * 1989-03-23 1990-11-06 Allegheny Ludlum Corporation Method of domain refinement of oriented silicon steel by using flux-printing
CN1039915C (en) * 1989-07-05 1998-09-23 新日本制铁株式会社 Production of grain-oriented silicon steel sheets having insulating film formed thereon
FR2672305B1 (en) * 1991-02-05 1994-05-06 Usine Aciers Chatillon Gueugnon PROCESS FOR FORMING AN ADHERENT INSULATING COATING ON A MAGNETIC STEEL SHEET.
EP0555867B1 (en) * 1992-02-13 2000-12-06 Nippon Steel Corporation Oriented electrical steel sheet having low core loss and method of manufacturing same
JP4527225B2 (en) * 2000-01-17 2010-08-18 ファインシンター三信株式会社 Manufacturing method of dust core
JP4216488B2 (en) * 2000-05-12 2009-01-28 新日本製鐵株式会社 Oriented electrical steel sheet and manufacturing method thereof
DE10130308B4 (en) * 2001-06-22 2005-05-12 Thyssenkrupp Electrical Steel Ebg Gmbh Grain-oriented electrical sheet with an electrically insulating coating
JP4700691B2 (en) 2005-07-14 2011-06-15 新日本製鐵株式会社 Grain-oriented electrical steel sheet having an insulating coating containing no chromium and its insulating coating agent
JP2010040666A (en) * 2008-08-01 2010-02-18 Toyota Motor Corp METHOD FOR FORMING THIN SiO2 FILM ON MAGNETIC MATERIAL
DE102008039326A1 (en) 2008-08-22 2010-02-25 IWT Stiftung Institut für Werkstofftechnik Preparing electrically insulated electric sheet, to prepare laminated magnetic core, comprises coating one side of sheet using liquid mixture comprising hydrolyzed and condensed metal organic monomer, and heat treating coated sheet
JP5353399B2 (en) * 2009-04-14 2013-11-27 Ｊｆｅスチール株式会社 Indirect measurement method for coating tension of grain-oriented electrical steel sheet
US9187830B2 (en) 2010-02-18 2015-11-17 Nippon Steel & Sumitomo Metal Corporation Non-oriented electrical steel sheet and manufacturing method thereof
CN103069038B (en) 2010-08-06 2014-02-19 杰富意钢铁株式会社 Grain oriented electrical steel sheet
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DE102010038038A1 (en) * 2010-10-07 2012-04-12 Thyssenkrupp Electrical Steel Gmbh Process for producing an insulation coating on a grain-oriented electro-steel flat product and electro-flat steel product coated with such an insulation coating
DE102010054509A1 (en) 2010-12-14 2012-06-14 Thyssenkrupp Electrical Steel Gmbh Method for producing a grain-oriented electrical strip
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EP3653753A4 (en) 2017-07-13 2021-04-07 Nippon Steel Corporation Oriented electromagnetic steel plate
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KR102543352B1 (en) 2017-11-13 2023-06-16 닛폰세이테츠 가부시키가이샤 Coating liquid for forming insulating coating for grain-oriented electrical steel sheet, and method for producing grain-oriented electrical steel sheet
EP3495430A1 (en) 2017-12-07 2019-06-12 Henkel AG & Co. KGaA Chromium-free and phosphate-free coating for electrical insulation of magnetic circuit band
JP7016358B2 (en) 2018-02-06 2022-02-04 Ｊｆｅスチール株式会社 Electrical steel sheet with insulating film and its manufacturing method
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WO2019188976A1 (en) 2018-03-30 2019-10-03 Ｊｆｅスチール株式会社 Method for producing grain-oriented electrical steel sheet and continuous film-forming device
KR102542094B1 (en) 2018-05-30 2023-06-12 제이에프이 스틸 가부시키가이샤 Electrical steel sheet with insulation coating and method for manufacturing the same, iron core of transformer using the electrical steel sheet, transformer and method for reducing dielectric loss of transformer
BR112020026927B1 (en) 2018-07-13 2023-10-24 Nippon Steel Corporation ELECTRIC STEEL SHEET WITH GRAIN ORIENTED AND PRODUCTION METHOD THEREOF
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EP4095285A1 (en) 2018-08-17 2022-11-30 Jfe Steel Corporation A production apparatus for a treatment solution for forming an insulating coating
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WO2020066469A1 (en) 2018-09-28 2020-04-02 Ｊｆｅスチール株式会社 Treating agent for use in formation of chromium-free insulating coating film, and oriented electromagnetic steel sheet having insulating coating film attached thereto and method for manufacturing same
US20220033921A1 (en) 2018-09-28 2022-02-03 Jfe Steel Corporation Method for producing grain-oriented electrical steel sheet and cold-rolling facility
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WO2020088764A1 (en) 2018-10-31 2020-05-07 Thyssenkrupp Electrical Steel Gmbh Method for producing a grain-oriented flat steel product for electromagnetic applications, flat steel product for electromagnetic applications, and transformer core stack produced from such a flat steel product
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JP7092214B2 (en) 2019-01-16 2022-06-28 日本製鉄株式会社 Directional electrical steel sheet and its manufacturing method
JP7200687B2 (en) * 2019-01-16 2023-01-10 日本製鉄株式会社 Grain-oriented electrical steel sheet and manufacturing method thereof
WO2020149324A1 (en) 2019-01-16 2020-07-23 日本製鉄株式会社 Grain-oriented electromagnetic steel sheet, and steel sheet which can be used as raw material sheet for grain-oriented electromagnetic steel
EP3693496A1 (en) 2019-02-06 2020-08-12 Rembrandtin Lack GmbH Nfg.KG Aqueous composition for coating grain-oriented steel
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WO2021084793A1 (en) 2019-10-31 2021-05-06 Ｊｆｅスチール株式会社 Electromagnetic steel sheet with insulation coating film
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DE102020134300A1 (en) 2020-12-18 2022-06-23 Vacuumschmelze Gmbh & Co. Kg Water-based alkaline composition for forming an insulating layer of an annealing separator, coated soft magnetic alloy and method of manufacturing a coated soft magnetic ribbon
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EP4357468A1 (en) 2021-06-30 2024-04-24 JFE Steel Corporation Grain-oriented electromagnetic steel sheet manufacturing method and rolling equipment for manufacturing grain-oriented electromagnetic steel sheet
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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2564864A (en) * 1948-07-02 1951-08-21 Parker Rust Proof Co Method of and solution for increasing resistance to corrosion
US3150015A (en) * 1961-08-29 1964-09-22 Allegheny Ludlum Steel Insulation for silicon steel
US3207636A (en) * 1962-06-26 1965-09-21 Yawata Iron & Steel Co Method for coating silicon steel transformer sheets and composition
US3522113A (en) * 1968-01-02 1970-07-28 Armco Steel Corp Potassium silicate coated silicon steel article
US3522108A (en) * 1966-03-18 1970-07-28 Nippon Steel Corp Method of forming electric insulating films on al - containing silicon steel sheet and surface-coated al-containing silicon steel sheet
US3528863A (en) * 1966-06-09 1970-09-15 Westinghouse Electric Corp Glass-coated electrical steel sheet
US3533861A (en) * 1966-06-09 1970-10-13 Westinghouse Electric Corp Method of improving the magnetostriction and core loss of cube-on-face oriented magnetic steels
US3670278A (en) * 1966-06-09 1972-06-13 Westinghouse Electric Corp Bonded core structure comprising a plurality of glass coated electrical steel sheets

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2920296A (en) * 1955-01-07 1960-01-05 Gen Electric Reduction of transformer noise due to magnetostrictive effects
DE1521610A1 (en) * 1964-08-13 1969-09-18 Allegheny Ludlum Steel Isolation coatings for silicon steels
US3615918A (en) * 1969-03-28 1971-10-26 Armco Steel Corp Method of annealing with a magnesia separator containing a decomposable phosphate

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2564864A (en) * 1948-07-02 1951-08-21 Parker Rust Proof Co Method of and solution for increasing resistance to corrosion
US3150015A (en) * 1961-08-29 1964-09-22 Allegheny Ludlum Steel Insulation for silicon steel
US3207636A (en) * 1962-06-26 1965-09-21 Yawata Iron & Steel Co Method for coating silicon steel transformer sheets and composition
US3522108A (en) * 1966-03-18 1970-07-28 Nippon Steel Corp Method of forming electric insulating films on al - containing silicon steel sheet and surface-coated al-containing silicon steel sheet
US3528863A (en) * 1966-06-09 1970-09-15 Westinghouse Electric Corp Glass-coated electrical steel sheet
US3533861A (en) * 1966-06-09 1970-10-13 Westinghouse Electric Corp Method of improving the magnetostriction and core loss of cube-on-face oriented magnetic steels
US3670278A (en) * 1966-06-09 1972-06-13 Westinghouse Electric Corp Bonded core structure comprising a plurality of glass coated electrical steel sheets
US3522113A (en) * 1968-01-02 1970-07-28 Armco Steel Corp Potassium silicate coated silicon steel article

Cited By (81)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3985583A (en) * 1973-11-17 1976-10-12 Kawasaki Steel Corporation Method for forming an insulating coating on an oriented silicon steel sheet
US4238534A (en) * 1975-08-22 1980-12-09 Kawasaki Steel Corporation Method for forming a heat-resistant coating on an oriented silicon steel sheet
US4552596A (en) * 1978-07-26 1985-11-12 Nippon Steel Corporation Grain-oriented electromagnetic steel sheet with improved watt loss
EP0008385A1 (en) * 1978-07-26 1980-03-05 Nippon Steel Corporation Grain-oriented electromagnetic steel sheet and method for its production
US4293350A (en) * 1978-07-26 1981-10-06 Nippon Steel Corporation Grain-oriented electromagnetic steel sheet with improved watt loss
EP0033878A2 (en) * 1980-01-25 1981-08-19 Nippon Steel Corporation Method for treating an electromagnetic steel sheet by laser-beam irradiation
EP0033878A3 (en) * 1980-01-25 1981-09-30 Nippon Steel Corporation An electromagnetic steel sheet treated by laser-beam irradiation and method for treating an electromagnetic steel sheet
US4363677A (en) * 1980-01-25 1982-12-14 Nippon Steel Corporation Method for treating an electromagnetic steel sheet and an electromagnetic steel sheet having marks of laser-beam irradiation on its surface
EP0087587A1 (en) * 1980-01-25 1983-09-07 Nippon Steel Corporation An electromagnetic steel sheet treated by laser-beam irradiation
EP0100638A2 (en) 1982-07-30 1984-02-15 Armco Advanced Materials Corporation Laser treatment of electrical steel
US4456812A (en) * 1982-07-30 1984-06-26 Armco Inc. Laser treatment of electrical steel
US5129965A (en) * 1990-07-20 1992-07-14 Nippon Steel Corporation Method of producing grain oriented silicon steel sheets each having a low watt loss and a mirror surface
US5565272A (en) * 1991-07-10 1996-10-15 Nippon Steel Corporation Grain oriented silicon steel sheet having excellent primary film properties
EP0565029A1 (en) * 1992-04-07 1993-10-13 Nippon Steel Corporation Grain oriented silicon steel sheet having low core loss and method of manufacturing same
US5507883A (en) * 1992-06-26 1996-04-16 Nippon Steel Corporation Grain oriented electrical steel sheet having high magnetic flux density and ultra low iron loss and process for production the same
EP0577124A2 (en) * 1992-07-02 1994-01-05 Nippon Steel Corporation Grain oriented electrical steel sheet having high magnetic flux density and ultra low iron loss and process for producing the same
EP0577124A3 (en) * 1992-07-02 1994-09-21 Nippon Steel Corp Grain oriented electrical steel sheet having high magnetic flux density and ultra low iron loss and process for producing the same
EP1108794A1 (en) * 1999-12-03 2001-06-20 Kawasaki Steel Corporation Electrical steel sheet suitable for compact iron core and manufacturing method therefor
US6562473B1 (en) 1999-12-03 2003-05-13 Kawasaki Steel Corporation Electrical steel sheet suitable for compact iron core and manufacturing method therefor
US20020192511A1 (en) * 2001-05-18 2002-12-19 Martin Hruschka Functional coating and method of producing same, in particular to prevent wear or corrosion or for thermal insulation
US20090101248A1 (en) * 2004-11-30 2009-04-23 Jfe Steel Corporation Grain-Oriented Electrical Steel Sheet and Process for Producing the Same
US8177920B2 (en) 2004-11-30 2012-05-15 Jfe Steel Corporation Grain-oriented electrical steel sheet and process for producing the same
EP2022874A1 (en) * 2006-05-19 2009-02-11 Nippon Steel Corporation Directional electromagnetic steel sheet having high tension insulating coating film and method for processing the insulating coating film
US20090233114A1 (en) * 2006-05-19 2009-09-17 Nippon Steel Corporation Grain-Oriented Electrical Steel Sheet Having High Tensile Strength Insulating Film and Method of Treatment of Such Insulating Film
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US11827961B2 (en) 2020-12-18 2023-11-28 Vacuumschmelze Gmbh & Co. Kg FeCoV alloy and method for producing a strip from an FeCoV alloy

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FR2154625B1 (en) 1975-01-03
DE2247269A1 (en) 1973-04-05
BE789262A (en) 1973-01-15
IT965500B (en) 1974-01-31
CA986793A (en) 1976-04-06
BR7206706D0 (en) 1973-08-21
DE2247269C3 (en) 1981-05-14
GB1411094A (en) 1975-10-22
SE379799B (en) 1975-10-20
FR2154625A1 (en) 1973-05-11
JPS4839338A (en) 1973-06-09
DE2247269B2 (en) 1977-09-29
JPS5328375B2 (en) 1978-08-14

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