US2938813A - Insulated coating for silicon steel sheet - Google Patents
Insulated coating for silicon steel sheet Download PDFInfo
- Publication number
- US2938813A US2938813A US619411A US61941156A US2938813A US 2938813 A US2938813 A US 2938813A US 619411 A US619411 A US 619411A US 61941156 A US61941156 A US 61941156A US 2938813 A US2938813 A US 2938813A
- Authority
- US
- United States
- Prior art keywords
- silicon steel
- steel sheet
- strip
- film
- coating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 229910000976 Electrical steel Inorganic materials 0.000 title claims description 47
- 239000011248 coating agent Substances 0.000 title claims description 32
- 238000000576 coating method Methods 0.000 title claims description 32
- 239000007864 aqueous solution Substances 0.000 claims description 18
- 238000010438 heat treatment Methods 0.000 claims description 17
- KHADWTWCQJVOQO-UHFFFAOYSA-N zinc;oxido-(oxido(dioxo)chromio)oxy-dioxochromium Chemical compound [Zn+2].[O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O KHADWTWCQJVOQO-UHFFFAOYSA-N 0.000 claims description 16
- 238000009413 insulation Methods 0.000 claims description 14
- 230000001464 adherent effect Effects 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 9
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 26
- 235000011187 glycerol Nutrition 0.000 description 13
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 8
- 239000004327 boric acid Substances 0.000 description 8
- 239000000243 solution Substances 0.000 description 8
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000003921 oil Substances 0.000 description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 150000004760 silicates Chemical class 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 239000011787 zinc oxide Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 239000000378 calcium silicate Substances 0.000 description 1
- 229910052918 calcium silicate Inorganic materials 0.000 description 1
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 description 1
- 229910000423 chromium oxide Inorganic materials 0.000 description 1
- 229940035427 chromium oxide Drugs 0.000 description 1
- 239000008199 coating composition Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 235000020030 perry Nutrition 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000002966 varnish Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Classifications
-
- 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
- the present invention relates to the method of producmg an interlamellar insulated coating on silicon steel sheet or strip.
- insulated films coated on silicon steel sheet or strip of the prior art e.g., varnish-coated films, and iron oxide coated films have been flaked ofif, carburized, and deteriorated, so that the effect of insulation has been reduced.
- the insulated film of my invention is produced by coating an aqueous solution containing 10-60 Weight percent of zinc bichromate on the surface of silicon steel sheet or strip with a thin and uniform coating thereon, and heating the thus coated silicon steel sheet or strip at a temperature between 500 and 700 C. for a period of ten to forty seconds.
- the insulated film of my invention is also formed by heating silicon steel sheet or strip coated with an aqueous solution of the same composition added with 1-4% of glycerine at a temperature of ZOO-500 C.
- 2-5% of boric acid may be added to the aqueous solution with a view to making the insulated film glossy and scratch-proof.
- the insulated film may be produced in any other range than the above-mentioned concentration of zinc bichromate.
- concentration below 10% of Zinc bichromate the coated film becomes very thin, which results in a poor insulation property, and the film is produced in excessive thickness if the aqueous solution nited States Patent contains more than 60% of zinc bichromate. Accordingly, I limit the concentration range of 10-60% of zincbichromate in my invention.
- the heating temperature of the base material at a temperature of 200-500 C. is suflicient, because the solution adheres tightly to the base sheet or strip with the reaction of zinc bichromate and glycerine at a lower tempertaure and with the subsequent solidification of the thus reacted. product.
- boric acid may be added in the range of 25% in order to develop a glossy and smooth surface on the silicon steel sheet or strip.
- the aqueous solution thus produced may be employed as it is, and besides, as described hereinbefore, the addition of glycerine and boric acid is effected as follows: 4 kg. of boric acid is dissolved and stirred in water, then litres of an aqueous solution is produced by adding more water thereto, and the solution is cooled to the room temperature, finally 2 kg. of glycerine is added thereto.
- the aqueous solution thus produced is uniformly coated on the surface of silicon steel sheet or strip by a conventional manner. Removal of oxides present on the surface of silicon steel sheet or strip is not required by means of pickling before the base sheet or strip is coated with the solution of my invention.
- oxides and silicates e.g., silica, iron oxide, calcium silicate, and magnesium oxide
- concentration of the aqueous solution and the amount of coating may be determined by taking the condition of the surface of silicon steel sheet or strip into consideration.
- the silicon steel sheet or strip thus coated with the aqueous solution with no glycerine is heated at a temperature of 500-700" C. for aperiod of 10-40 seconds. At higher temperatures, a heating process is finished in a shorter period of time. The heating time depends on the amount of coating. 'It is preferable to heat silicon steelsheet or strip coated with the aqueous solution of 30% zinc bichromate with the amount of'25 cc. per
- the insulated film thus produced is regarded as the coated film comprising complicated chromates consisting of chromium-oxide, iron, and zinc, and in some cases,
- the film will not be flaked oii by being bent at an angle of 180 with the radius of'25 millimeters.
- An anneal in the hydrogen at the temperature of 800 C. after the formation of the film results in a negligible reduction of insulation resistance, thereby nothing is affected to the practical application.
- Interlamellar resistance of film As described hereinbefore, corrosion of silicon steel sheet or strip is prevented eifectively by the coated film of my invention.
- the transformer oil will not attack the film, and besides, the film will not deteriorate the transformer oil.
- the formation of the film does not destroy the magnetic property of silicon steel sheet or strip.
- a method of producing an insulated coating on the surface of silicon steel sheet or strip which comprises coating an aqueous solution of 10-60 weight percent of zinc bichromate in the form of a thin and uniform film on the surface of the silicon steel, and heating the thus coated silicon steel at a temperature of 500-700 C. for a period of 10-40 seconds, thereby a firmly adherent film of insulation is produced on said silicon steel sheet or strip.
- a method of producing an insulating coating on the surface of silicon steel which comprises coating said surface with a thin and uniform film of an aqueous solution consisting essentially of from 10 to 60 percent by weight of zinc bichromate, from to 5 percent by weight of boric acid and from 1 to 5 percent by weight of glycerine, and heating the thus coated silicon steel at a temperature of from 200 to 500 C. for a period of from to 40 seconds, thereby forming a firmly adherent film of insulation on the silicon steel.
- a method of producing an insulating coating on the surface of silicon steel which comprises coating said surface witha thin and uniform film of an aqueous solution consisting essentially of from 10'to 60 percent by weight of zinc bichromate and from 2 to 5 percent by weight of boric acid and heating the thus coated silicon steel at a consisting essentially of from 10 to 60 percent by weight of zinc bichromate and from l to 5 percent by weight of glycerine and heating the thus coated silicon steel at a temperature of from 200 to 500 C. for a period of from 10 to 40'seconds, thereby forming a firmly adherent film of insulation on the silicon steel.
- a method of producing an insulating coating on the surface of silicon steel which comprises coating said surface with a thin and uniform film of an aqueous solution consisting essentially of from 10 to 60 percent by weight of zinc bichromate, from 2 to 5 percent by weight of boric acid and from 1 to 5 percent by weight of glycerin, and heating the thus coated silicon steel at a temperature of from 200 to 500 C. for a period of from 10 to 40 seconds,-thereby forming a firmly adherent film of insulation on the silicon steel.
- a method of producing an insulating coating on the surface of silicon steel which comprises coating said surface with a thin and uniform film of an aqueous solution consisting essentially of from 10 to 60 percent by weight of zinc bichromate, from 0 to 5 percent by weight of boric acid and from 0 to 5 percent by weight of glycerine, and heating the thus coated silicon steel at a temperature of from 500 to 700 C. for a period of from 10 to 40 seconds, thereby forming a firmly adherent film of insulation on the silicon steel.
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- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Treatment Of Metals (AREA)
Description
INSULATED COATING FOR SILICON STEEL SHEET Kamematsu Matsuda, Tobata City,
Yawata Iron and Steel Co., poration of Japan Japan, assignor to Ltd., Tokyo, Japan, a cor- The present invention relates to the method of producmg an interlamellar insulated coating on silicon steel sheet or strip.
With the recent development of the quality of silicon steel sheet or strip, it is very frequent to anneal it in a hydrogen atmosphere at the temperature of 800 C. for the purpose of removing strain after the working steps, such as, shearing, punching, and stamping. In such cases, insulated films coated on silicon steel sheet or strip of the prior art, e.g., varnish-coated films, and iron oxide coated films have been flaked ofif, carburized, and deteriorated, so that the effect of insulation has been reduced.
Recently the adoption of phosphate coating has been introduced to provide insulation, but resulted in a considerable reduction of insulation after an anneal in an atmosphere containing a substantial amount of hydrogen.
It is one object of my invention to provide a firmly adherent coating of insulation on silicon steel sheet or strip.
It is another object of the invention to provide a new and novel method of producing a strong adherent insulated coating on silicon steel sheet or strip.
It is another object of the invention to provide a firmly adherent insulated coating on silicon steel sheet or strip with a superior property for interlamellar resistance and space factor.
It is another object of the invention to provide an excellent insulated coating on silicon steel sheet or strip which is never attacked by the transformer oil, nor affects the transformer oil badly.
It is an additional object of the invention to provide a superior insulated coating on silicon steel sheet or strip with an excellent resistance to corrosion and scratch or multilation.
With the above and other objects in view that will hereinafter appear, the nature of the invention will be more fully understood by following the detailed description and the appended claims.
The insulated film of my invention is produced by coating an aqueous solution containing 10-60 Weight percent of zinc bichromate on the surface of silicon steel sheet or strip with a thin and uniform coating thereon, and heating the thus coated silicon steel sheet or strip at a temperature between 500 and 700 C. for a period of ten to forty seconds. The insulated film of my invention is also formed by heating silicon steel sheet or strip coated with an aqueous solution of the same composition added with 1-4% of glycerine at a temperature of ZOO-500 C. Moreover, 2-5% of boric acid may be added to the aqueous solution with a view to making the insulated film glossy and scratch-proof.
The insulated film may be produced in any other range than the above-mentioned concentration of zinc bichromate. However, in the concentration below 10% of Zinc bichromate, the coated film becomes very thin, which results in a poor insulation property, and the film is produced in excessive thickness if the aqueous solution nited States Patent contains more than 60% of zinc bichromate. Accordingly, I limit the concentration range of 10-60% of zincbichromate in my invention.
It is necessary to heat silicon steel sheet or strip coated with the solution of the invention above the temperature of 500 C. when the solution does not contain glycerine. Under the temperature of 500 C., the incomplete decomposition of zinc bichromate and the subsequent insufiicient reaction on the surface of silicon steel sheet or strip will result in a hydrous film, consequently the film absorbs moisture gradually in the course of a prolonged exposure in the air after the formation of the film, which causes a considerably reduced insulation. Accordingly, it is required to heat silicon steel sheet or strip coated with the aqueous solution above the temperature of 500 0, preferably above the temperature of 600 C. in order to develop the desired results.
With the coating solution added with 15% of glycerine, the heating temperature of the base material at a temperature of 200-500 C. is suflicient, because the solution adheres tightly to the base sheet or strip with the reaction of zinc bichromate and glycerine at a lower tempertaure and with the subsequent solidification of the thus reacted. product. However, it does not matter to heat above the temperature of 500 C. if it is required to do so. As the film produced by coating an aqueous solution of zinc bichromate with or without an addition of glycerine. is rough and dull in appearance, and easily mutilated, boric acid may be added in the range of 25% in order to develop a glossy and smooth surface on the silicon steel sheet or strip.
An embodiment of the invention is described hereinafter. A mixture of 8.14 kg of zinc oxide and 20 kg of anhydrous chromate is dissolved in Water, stirred, and reacted together. The reaction is as follows:
In this reaction, the equivalents of zinc oxide and anhydrous chromate, respectively, must be added. If the amount of CrO is in excess, the film tends to be hydrous, on the contrary, the film tends to be thick due to the remains of ZnO if a litttle amount of CrO is present.
The aqueous solution thus produced may be employed as it is, and besides, as described hereinbefore, the addition of glycerine and boric acid is effected as follows: 4 kg. of boric acid is dissolved and stirred in water, then litres of an aqueous solution is produced by adding more water thereto, and the solution is cooled to the room temperature, finally 2 kg. of glycerine is added thereto.
The aqueous solution thus produced is uniformly coated on the surface of silicon steel sheet or strip by a conventional manner. Removal of oxides present on the surface of silicon steel sheet or strip is not required by means of pickling before the base sheet or strip is coated with the solution of my invention.
In the course of the production of silicon steel sheet or strip, various oxides and silicates, e.g., silica, iron oxide, calcium silicate, and magnesium oxide, are formed on the surface of silicon steel sheet or strip. The completeelimination of such oxides and silicates is not required for the formation of the insulated film in accordance with the invention. As the higher insulation efficiency is acquired in case of silicon steel sheet or strip with oxides present on the surface thereof than in the base sheet or strip without oxides, the concentration of the aqueous solution and the amount of coating may be determined by taking the condition of the surface of silicon steel sheet or strip into consideration.
The silicon steel sheet or strip thus coated with the aqueous solution with no glycerine is heated at a temperature of 500-700" C. for aperiod of 10-40 seconds. At higher temperatures, a heating process is finished in a shorter period of time. The heating time depends on the amount of coating. 'It is preferable to heat silicon steelsheet or strip coated with the aqueous solution of 30% zinc bichromate with the amount of'25 cc. per
square meter at the temperature of 600 C. for a period of about twenty seconds. I p v 7 With the coating solution added with glycerine, care must be taken to the heating speed. Gradual heating is necessary, because the film will be peeled off owing to an abrupt heating. The heating speed must be determined according to the concentration of the coating solution and the amountof coating to be applied, but an appropriate speed of heating can be readily found bythose skilled in the art. 1 The insulated film thus produced is regarded as the coated film comprising complicated chromates consisting of chromium-oxide, iron, and zinc, and in some cases,
silicates. v i
. The film will not be flaked oii by being bent at an angle of 180 with the radius of'25 millimeters. An anneal in the hydrogen at the temperature of 800 C. after the formation of the film results in a negligible reduction of insulation resistance, thereby nothing is affected to the practical application. I
The following table represents the comparative results.
Interlamellar resistance of film As described hereinbefore, corrosion of silicon steel sheet or strip is prevented eifectively by the coated film of my invention. The transformer oil will not attack the film, and besides, the film will not deteriorate the transformer oil. Moreover, the formation of the film does not destroy the magnetic property of silicon steel sheet or strip.
From the foregoing description, it is thought that the novel details of insulated coating, the manner of coating, and the advantages of the invention, will be apparent to those skilled in the art to which it relates.
It is of course to be understood that the details of coating composition and method may be variously changed and modified without departing from the spirit and scope of my invention as set forth in the appended claims.
Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is:
1. A method of producing an insulated coating on the surface of silicon steel sheet or strip which comprises coating an aqueous solution of 10-60 weight percent of zinc bichromate in the form of a thin and uniform film on the surface of the silicon steel, and heating the thus coated silicon steel at a temperature of 500-700 C. for a period of 10-40 seconds, thereby a firmly adherent film of insulation is produced on said silicon steel sheet or strip.
2. A method of producing an insulating coating on the surface of silicon steel which comprises coating said surface with a thin and uniform film of an aqueous solution consisting essentially of from 10 to 60 percent by weight of zinc bichromate, from to 5 percent by weight of boric acid and from 1 to 5 percent by weight of glycerine, and heating the thus coated silicon steel at a temperature of from 200 to 500 C. for a period of from to 40 seconds, thereby forming a firmly adherent film of insulation on the silicon steel.
3. A method of producing an insulating coating on the surface of silicon steel which comprises coating said surface witha thin and uniform film of an aqueous solution consisting essentially of from 10'to 60 percent by weight of zinc bichromate and from 2 to 5 percent by weight of boric acid and heating the thus coated silicon steel at a consisting essentially of from 10 to 60 percent by weight of zinc bichromate and from l to 5 percent by weight of glycerine and heating the thus coated silicon steel at a temperature of from 200 to 500 C. for a period of from 10 to 40'seconds, thereby forming a firmly adherent film of insulation on the silicon steel.
5. A method of producing an insulating coating on the surface of silicon steel which comprises coating said surface with a thin and uniform film of an aqueous solution consisting essentially of from 10 to 60 percent by weight of zinc bichromate, from 2 to 5 percent by weight of boric acid and from 1 to 5 percent by weight of glycerin, and heating the thus coated silicon steel at a temperature of from 200 to 500 C. for a period of from 10 to 40 seconds,-thereby forming a firmly adherent film of insulation on the silicon steel.
6. A method of producing an insulating coating on the surface of silicon steel which comprises coating said surface with a thin and uniform film of an aqueous solution consisting essentially of from 10 to 60 percent by weight of zinc bichromate, from 0 to 5 percent by weight of boric acid and from 0 to 5 percent by weight of glycerine, and heating the thus coated silicon steel at a temperature of from 500 to 700 C. for a period of from 10 to 40 seconds, thereby forming a firmly adherent film of insulation on the silicon steel.
References Cited in the file of this patent UNITED STATES PATENTS 1,147,971 Perry July 27, 1915 2,210,850 Curtin Aug. 6, 1940 2,472,592 Kiefer June 7, 1949 2,618,578 Kreml Nov. 18, 1952 2,788,292 Giesker et al. Apr. 9, 1957 FOREIGN PATENTS Great Britain Jan. 4, 1888
Claims (1)
1. A METHOD FO PRODUCING AN INSULATED COATING ON THE SURFACE OF SILICON STEEL SHEET OR STRIP WHICH COMPRISES COATING AN AQUEOUS SOLUTION OF 10-60 WEIGHT PERCENT OF ZINC BICHROMATE IN THE FORM OF A THIN AND UNIFORM FILM ON THE SURFACE OF THE SILICON STEEL, AND HEATING THE THUS COATED SILICON STEEL AT A TEMPERATURE OF 500*-700*C. FOR A PERIOD OF 10-40 SECONDS, THEREBY A FIRMLY ADHERENT FILM OF INSULATION IS PRODUCED ON SAID SILICON STEEL SHEET OR STRIP.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2938813X | 1955-11-02 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2938813A true US2938813A (en) | 1960-05-31 |
Family
ID=17800357
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US619411A Expired - Lifetime US2938813A (en) | 1955-11-02 | 1956-10-31 | Insulated coating for silicon steel sheet |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2938813A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3299109A (en) * | 1961-09-29 | 1967-01-17 | Pfersee Chem Fab | Aluminium, titanium and zirconium chelate compounds of perfluoralkylcarboxylic acids and process for making same |
| US3484344A (en) * | 1965-05-10 | 1969-12-16 | Ransburg Electro Coating Corp | Production of electrically resistive coatings by anodic deposition from aqueous monoaluminum phosphate |
| US3632362A (en) * | 1969-06-27 | 1972-01-04 | Nippon Steel Corp | Insulation coating for electrical steel sheet and method of application |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1147971A (en) * | 1913-03-17 | 1915-07-27 | Robert S Perry | Composition for coating surfaces of iron and steel. |
| US2210850A (en) * | 1938-05-05 | 1940-08-06 | Curtin Howe Corp | Method of finishing ferrous metal surfaces |
| US2472592A (en) * | 1945-01-09 | 1949-06-07 | Allegheny Ludlum Steel | Inorganic insulating coating for electrical steel sheet and strip |
| US2618578A (en) * | 1950-10-13 | 1952-11-18 | Armco Steel Corp | Blackening stainless steel |
| US2788292A (en) * | 1951-10-15 | 1957-04-09 | Autoyre Co Inc | Method of treating chromium surfaces |
-
1956
- 1956-10-31 US US619411A patent/US2938813A/en not_active Expired - Lifetime
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1147971A (en) * | 1913-03-17 | 1915-07-27 | Robert S Perry | Composition for coating surfaces of iron and steel. |
| US2210850A (en) * | 1938-05-05 | 1940-08-06 | Curtin Howe Corp | Method of finishing ferrous metal surfaces |
| US2472592A (en) * | 1945-01-09 | 1949-06-07 | Allegheny Ludlum Steel | Inorganic insulating coating for electrical steel sheet and strip |
| US2618578A (en) * | 1950-10-13 | 1952-11-18 | Armco Steel Corp | Blackening stainless steel |
| US2788292A (en) * | 1951-10-15 | 1957-04-09 | Autoyre Co Inc | Method of treating chromium surfaces |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3299109A (en) * | 1961-09-29 | 1967-01-17 | Pfersee Chem Fab | Aluminium, titanium and zirconium chelate compounds of perfluoralkylcarboxylic acids and process for making same |
| US3484344A (en) * | 1965-05-10 | 1969-12-16 | Ransburg Electro Coating Corp | Production of electrically resistive coatings by anodic deposition from aqueous monoaluminum phosphate |
| US3632362A (en) * | 1969-06-27 | 1972-01-04 | Nippon Steel Corp | Insulation coating for electrical steel sheet and method of application |
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