EP0057983A2 - Method for producing coated grain oriented silicon steel - Google Patents

Method for producing coated grain oriented silicon steel Download PDF

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Publication number
EP0057983A2
EP0057983A2 EP82300236A EP82300236A EP0057983A2 EP 0057983 A2 EP0057983 A2 EP 0057983A2 EP 82300236 A EP82300236 A EP 82300236A EP 82300236 A EP82300236 A EP 82300236A EP 0057983 A2 EP0057983 A2 EP 0057983A2
Authority
EP
European Patent Office
Prior art keywords
steel
coating
silicon steel
grain oriented
oriented silicon
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.)
Withdrawn
Application number
EP82300236A
Other languages
German (de)
French (fr)
Other versions
EP0057983A3 (en
Inventor
Charles Dean Boyer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Allegheny Ludlum Steel Corp
Original Assignee
Allegheny Ludlum Steel Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Allegheny Ludlum Steel Corp filed Critical Allegheny Ludlum Steel Corp
Publication of EP0057983A2 publication Critical patent/EP0057983A2/en
Publication of EP0057983A3 publication Critical patent/EP0057983A3/en
Withdrawn legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
    • C21D8/1277—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties involving a particular surface treatment
    • C21D8/1283—Application of a separating or insulating coating
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • 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
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/48—After-treatment of electroplated surfaces
    • C25D5/50—After-treatment of electroplated surfaces by heat-treatment
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D9/00—Electrolytic coating other than with metals
    • C25D9/04—Electrolytic coating other than with metals with inorganic materials
    • C25D9/08—Electrolytic coating other than with metals with inorganic materials by cathodic processes
    • C25D9/10—Electrolytic coating other than with metals with inorganic materials by cathodic processes on iron or steel
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
    • C21D8/1244—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the heat treatment(s) being of interest
    • C21D8/1272—Final recrystallisation annealing

Definitions

  • the present invention relates to a method for producing coated grain oriented silicon steel.
  • the method of the invention provides an improvement in the conventional practice of producing grain oriented silicon steel wherein a melt of the steel is produced containing from O2 to D6% carbon, up to .008% boron, up to .01% nitrogen, up to .05% aluminium and from 2.5 to 4% silicon, with the balance iron.
  • a melt of the steel is produced containing from O2 to D6% carbon, up to .008% boron, up to .01% nitrogen, up to .05% aluminium and from 2.5 to 4% silicon, with the balance iron.
  • the melt is cast, hot rolled, cold rolled and decarburized.
  • a coating is applied to the surface of the steel comprising Mg (OH) 2 and Si0 2 and thereafter the steel is final texture annealed with the coating thereon. It has been found that with this coating a significant improvement is achieved with respect to the magnetic properties of the steel after texture annealing.
  • the coating may comprise in percent by weight, 87.5 to 97Mg(OH) 2 and 3 to 12.5 Si0 2 , preferably 88 to 96 Mg(OH) 2 and 4 to 12 Si0 2 . It is preferred practice that the coating be electrolytically applied by the use of a magnesium acetate electrolyte. The coating may also be applied by mixing the coating constituents with water and applying as a slurry, but this practice is not preferred. Also the constituents could be applied as individual layers, but this is likewise not preferred.
  • This steel was in the conventional manner hot rolled, and cold rolled to a thickness of 0.264mm (.0104 in.) prior to conventional decarburization.
  • the surfaces of various samples of the steel were coated both in the conventional practice and in accordance with the practice of the invention and the magnetic properties e.g. core loss and magnetic permeability at 10 oersteds, were determined as reported in Table 1.
  • Table II indicates the improvement achieved in accordance with the practice of the invention over conventional practice from the standpoint of the relatively shorter time required to deposit on the steel surface a coating of similar weight.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Metallurgy (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Electromagnetism (AREA)
  • Inorganic Chemistry (AREA)
  • Manufacturing Of Steel Electrode Plates (AREA)
  • Chemical Treatment Of Metals (AREA)
  • Heat Treatment Of Sheet Steel (AREA)

Abstract

A method for coating grain oriented silicon steel to improve its magnetic properties; the method including the steps of preparing a melt of said silicon steel, casting said steel, hot rolling said steel, cold rolling said steel and decarburizing said steel, and being characterised by applying to the surface of said steel a coating of Mg(OH)2 and Si02 and thereafter final texture annealing said steel in the conventional manner with said coating thereon.

Description

  • The present invention relates to a method for producing coated grain oriented silicon steel.
  • It is known to produce for electrical applications grain oriented silicon steel. More specifically, for this purpose the steel is melted, cast, hot rolled, subjected to one or more cold rollings, and intermediate normalizing treatment when two or more cold rollings are employed, decarburizing, application of a refractory oxide coating and final texture annealing to provide the desired grain orientation essential for achieving the required magnetic properties.
  • It is a primary object of the present invention to provide an improved electrolytic coating practice for use with grain oriented silicon steels which results in improved magnetic properties.
  • This and other objects of the invention as well as a more complete understanding thereof may be obtained from the following description and specific examples.
  • The method of the invention provides an improvement in the conventional practice of producing grain oriented silicon steel wherein a melt of the steel is produced containing from O2 to D6% carbon, up to .008% boron, up to .01% nitrogen, up to .05% aluminium and from 2.5 to 4% silicon, with the balance iron. In the conventional manner the melt is cast, hot rolled, cold rolled and decarburized. In accordance with the invention a coating is applied to the surface of the steel comprising Mg (OH)2 and Si02 and thereafter the steel is final texture annealed with the coating thereon. It has been found that with this coating a significant improvement is achieved with respect to the magnetic properties of the steel after texture annealing. With respect to the coating it may comprise in percent by weight, 87.5 to 97Mg(OH)2 and 3 to 12.5 Si02, preferably 88 to 96 Mg(OH)2 and 4 to 12 Si02. It is preferred practice that the coating be electrolytically applied by the use of a magnesium acetate electrolyte. The coating may also be applied by mixing the coating constituents with water and applying as a slurry, but this practice is not preferred. Also the constituents could be applied as individual layers, but this is likewise not preferred.
  • As a specific example of the practice of the invention a silicon steel of the following composition was used;
    Figure imgb0001
  • This steel was in the conventional manner hot rolled, and cold rolled to a thickness of 0.264mm (.0104 in.) prior to conventional decarburization. The surfaces of various samples of the steel were coated both in the conventional practice and in accordance with the practice of the invention and the magnetic properties e.g. core loss and magnetic permeability at 10 oersteds, were determined as reported in Table 1.
    Figure imgb0002
  • In this specific example all of the coatings were electrolytically deposited using a magnesium acetate electrolyte. As may be seen from the magnetic properties- reported in Table I when comparing the conventional coatings with the coatings in accordance with the invention, the Si02 addition generally improves core loss, particularly as the SiO2 content is increased above about 4%.
  • Table II indicates the improvement achieved in accordance with the practice of the invention over conventional practice from the standpoint of the relatively shorter time required to deposit on the steel surface a coating of similar weight.
    Figure imgb0003

Claims (5)

1. A method for producing grain oriented silicon steel including the steps of preparing a melt of said silicon steel, casting said steel, hot rolling said steel, cold rolling said steel and decarburizing said steel characterised in that the method comprises applying a coating to the surface of said steel of Mg(OH)2 and Si02 and final texture annealing said steel with said coating thereon.
2. The method of claim 1, characterised in that said coating comprises in percent by weight, 87.5 to 97 Mg(OH)2 and 3 to 12.5 Si02.
3. The method of claim 1, characterised in that said coating comprises in percent by weight, 88 to 96 Mg(OH)2 and 4 to 12 Si02.
4. The method of claim 1, 2 or 3, characterised in that said coating is electrolytically deposited.
5. The method of claim 4, characterised in that said coating is electrolytically deposited using a magnesium acetate electrolyte.
EP82300236A 1981-02-06 1982-01-18 Method for producing coated grain oriented silicon steel Withdrawn EP0057983A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US23234181A 1981-02-06 1981-02-06
US232341 1981-02-06

Publications (2)

Publication Number Publication Date
EP0057983A2 true EP0057983A2 (en) 1982-08-18
EP0057983A3 EP0057983A3 (en) 1983-01-12

Family

ID=22872725

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82300236A Withdrawn EP0057983A3 (en) 1981-02-06 1982-01-18 Method for producing coated grain oriented silicon steel

Country Status (6)

Country Link
EP (1) EP0057983A3 (en)
JP (1) JPS57145935A (en)
KR (1) KR830009247A (en)
CA (1) CA1197757A (en)
PL (1) PL234964A1 (en)
RO (1) RO84030B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0480265A1 (en) * 1990-10-03 1992-04-15 Nippon Steel Corporation Method of producing permalloy cores
EP0730039A1 (en) * 1995-02-28 1996-09-04 Armco Inc. Magnesia coating and process for producing grain oriented electrical steel for punching quality

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1100181A (en) * 1953-03-13 1955-09-16 Westinghouse Electric Corp Insulating coatings for magnetic sheets and manufacturing processes
FR1321837A (en) * 1962-05-08 1963-03-22 Thomson Houston Comp Francaise Process for coating iron alloys
GB922521A (en) * 1959-03-05 1963-04-03 Gen Electric Improvements in coated metallic sheet material and method of making same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1100181A (en) * 1953-03-13 1955-09-16 Westinghouse Electric Corp Insulating coatings for magnetic sheets and manufacturing processes
GB922521A (en) * 1959-03-05 1963-04-03 Gen Electric Improvements in coated metallic sheet material and method of making same
FR1321837A (en) * 1962-05-08 1963-03-22 Thomson Houston Comp Francaise Process for coating iron alloys

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0480265A1 (en) * 1990-10-03 1992-04-15 Nippon Steel Corporation Method of producing permalloy cores
EP0730039A1 (en) * 1995-02-28 1996-09-04 Armco Inc. Magnesia coating and process for producing grain oriented electrical steel for punching quality

Also Published As

Publication number Publication date
EP0057983A3 (en) 1983-01-12
KR830009247A (en) 1983-12-19
RO84030A (en) 1984-05-12
CA1197757A (en) 1985-12-10
JPS57145935A (en) 1982-09-09
PL234964A1 (en) 1982-09-13
RO84030B (en) 1984-06-30

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Inventor name: BOYER, CHARLES DEAN