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
  • C21D8/1244—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
  • C21D8/1266—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 between cold rolling steps
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
  • C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
  • C21D8/1216—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the working step(s) being of interest
  • C21D8/1233—Cold rolling
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
  • C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
  • C21D8/1244—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the heat treatment(s) being of interest
  • C21D8/1261—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 following hot rolling

Definitions

• ABSTRACT A process for producing silicon steel having a cubeon-edge orientation and a permeability of at least 1850 (G/Oe) at 10 oersteds, which includes the steps of: preparing a melt of steel consisting essentially of,
• the present invention relates to a process for producing electromagnetic silicon steel having a cube-on-edge orientation and a permeability of at least 1850 (G/O at oersteds.
• Oriented silicon steels containing 2.60 to 4.0% silicon are generally produced by processes which involve hot rolling, a double cold reduction, an anneal before each cold roll and a high temperature texture anneal. Characterizing these steels are permeabilities at 10 oersteds of from about 1790 to 1840 (G/O).
• G/O permeabilities at 10 oersteds of from about 1790 to 1840
• a number of patents have disclosed methods for producing silicon steels with permeabilities in excess of 1850 (G/O at 10 oersteds.
• 3,287,183, 3,632,456 and 3,636,579 appear to be the most interesting.
• a still more interest ing method is, however, described in a copending United States patent application. The application is No.
• Described herein is another, and improved method for producing silicon steel having a cube-on-edge orientation and a permeability of at least 1850 (6/0,) at 10 oersteds. It is primarily based upon the discovery that the melts of application Ser. No. 357,974 and another application filed concurrently herewith, can be prepared with boron added thereto. Boron has been successfully used to help develop high permeability in grain oriented silicon steels. The concurrently filed application is US. Ser. No. 524,831. It is primarily.
• melt of application Ser. No. 357,974 can be prepared with selenium replacing part or all of the sulfur contained therein.
• the present invention provides a method for producing silicon steel havinga cube-on-edge orientation and a permeability of at least 1850 (G/O at 10 oersteds.
• Involved therein are the steps of: preparing a melt of silicon steel consisting essentially of, by weight, up to 0.07% carbon, from 2.60 to 4.0% silicon, from 0.03% to 0.24% manganese, from 0.01 to 0.09% of material from the group consisting of sulfur and selenium, from 2 0.015 to 0.04% aluminum, up to 0.02% nitrogen, from 0.1 to 0.5% copper, from 0.00045 to 0.0035% boron, balance iron; casting the steel; hot rolling the steel into a hot rolled band; subjecting the steel to at least one cold rolling; subjecting the steel to a final annealing prior to the final cold rolling; decarburizing the steel; and final texture annealing the steel.
• Preferred conditions include annealing at a temperature of from l800 to 2125F,
• the steel melt must include silicon, aluminum, manganese, and sulfur and/or selenium. Silicon is necessary as it increases the steels resistivity, decreases its magnetostriction, decreases its magnetocrystalline anisotropy and hence decreases its core loss. Aluminum, manganese, and sulfur and/or selenium are necessary as they form inhibitors which are essential for controlling the steels orientation and "its properties which are dependent thereon.
• aluminum combines with nitrogen in the steel or from the atmosphere, to form aluminum nitride; and manganese combines with sulfur and/or selenium, and possibly copper, to form manganese sulfide and/or manganese copper sulfide, and/or manganese selenide and/or manganese copper selenide. All together, these compounds inhibit normal grain growth during the final texture anneal, while at the same time aiding in the development of secondary recrystallized grains having the desired cube-on-edge orientation. Copper, noted above for its presence in manganese inhibitors, can also be beneficial during processing. It is hypothesized that copper can lower the annealing temperature, lower the temperature from which the rapid cool can occur, improve rollability, simplify melting, and relax annealing atmosphere requirements. Moreover, copper increases the steels resistivity and decreases its core loss.
• a steel in which the process of the present invention is particularly adaptable to consists essentially of, by weight, from 0.02 to 0.07% carbon, from 2.65 to 3.25% silicon, from 0.05 to 0.20% manganese, from 0.02 to 0.07% of material from the group consisting of sulfur and selenium, from 0.015 to 0.04% aluminum, from 0.0030 to 0.0090% nitrogen, from 0.1 to 0.4% copper,
• the primary inhibitors are aluminum nitride, and compounds of manganese sulfide and manganese selenide.
• N criticality is placed upon the particular annealing atmosphere.
• Illustrative atmospheres therefore include nitrogen; reducing gases such as hydrogen; inert gases such as argon; air; and mixtures thereof.
• the improvement comprising the steps of carrying out said final anneal prior to the final cold rolling at a temperature of from 1400 to 2l50F for a period of from 15 seconds to 2 hours; cooling said steel from a temperature below 1700F and above 750F to a temperature at least as low as 500F with a liquid quenching medium or gaseous stream and from its maximum annealing temperature to said temperature below 1700F and above 750F at a rate which is no faster than one wherein the steel is cooled in a static atmosphere or in a continuous processing line where there is some relative motion between the atmosphere and the steel, although the only deliberate motion is that imparted to the steel; and cold rolling the cooled steel at a reduction of at least 80%; said melt consisting essentially, of, by weight, up to 0.07% carbon, from 2.60 to 4.0% silicon, from 0.03 to 0.24% manganese,
• a process for producing electromagnetic silicon steel having a cube-on-edge orientation and a peremeability of at least 1850 (6/0 at 10 oersteds which process includes the steps of: preparing a melt of silicon steel; casting said steel; hot rolling said steel into a hot rolled band; subjecting said steel to at least one cold tic atmosphere or in a continuous processing line where there is some relative motion between the atmosphere and the steel, although the only deliberate motion is that imparted to the steel.
• said steel consists essentially of, by weight, from 0.02 to 6 0.07% carbon, from 2.65 to 3.25% silicon, from 0.05 to 0.20% manganese, from 0.02 to 0.09% of material from the group consisting of sulfur and selenium, from 0.015 to 0.04% aluminum, from 0.0030 to 0.0090% nitrogen, from 0.1 to 0.4% copper, from 0.0005 to 0.0025% boron, balance iron.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Metallurgy (AREA)
• Materials Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Crystallography & Structural Chemistry (AREA)
• Thermal Sciences (AREA)
• Electromagnetism (AREA)
• Manufacturing Of Steel Electrode Plates (AREA)
• Soft Magnetic Materials (AREA)
• Heat Treatment Of Sheet Steel (AREA)
• Metal Rolling (AREA)

Priority Applications (16)

Applications Claiming Priority (1)

Publications (1)

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ID=24090895

Family Applications (1)

Country Status (14)

Cited By (7)

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Citations (9)

Family Cites Families (2)

• 1974
  • 1974-11-18 US US524846A patent/US3929522A/en not_active Expired - Lifetime
• 1975
  • 1975-09-17 CA CA235,675A patent/CA1041879A/en not_active Expired
  • 1975-09-22 GB GB38765/75A patent/GB1478739A/en not_active Expired
  • 1975-10-09 IT IT51715/75A patent/IT1047747B/it active
  • 1975-10-10 ES ES441705A patent/ES441705A1/es not_active Expired
  • 1975-10-24 FR FR7532699A patent/FR2291276A1/fr active Granted
  • 1975-10-27 BE BE2054634A patent/BE834876A/xx not_active IP Right Cessation
  • 1975-10-29 IN IN2080/CAL/1975A patent/IN143003B/en unknown
  • 1975-11-10 DE DE19752550426 patent/DE2550426A1/de active Granted
  • 1975-11-13 JP JP50136784A patent/JPS5843444B2/ja not_active Expired
  • 1975-11-17 YU YU02913/75A patent/YU291375A/xx unknown
  • 1975-11-18 PL PL1975184805A patent/PL106073B1/pl unknown
  • 1975-11-18 SE SE7512968A patent/SE414949B/xx unknown
  • 1975-11-18 AR AR261250A patent/AR208730A1/es active

Patent Citations (10)

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