[go: up one dir, main page]

US20090199935A1 - Method of production of high flux density grain-oriented silicon steel sheet - Google Patents

Method of production of high flux density grain-oriented silicon steel sheet Download PDF

Info

Publication number
US20090199935A1
US20090199935A1 US12/310,769 US31076907A US2009199935A1 US 20090199935 A1 US20090199935 A1 US 20090199935A1 US 31076907 A US31076907 A US 31076907A US 2009199935 A1 US2009199935 A1 US 2009199935A1
Authority
US
United States
Prior art keywords
hot rolling
seconds
bar
temperature
final
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.)
Abandoned
Application number
US12/310,769
Other languages
English (en)
Inventor
Akira Sakakura
Hiroshi Takechi
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.)
Nippon Steel Corp
Original Assignee
Individual
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 Individual filed Critical Individual
Assigned to NIPPON STEEL CORPORATION, SAKAKURA, AKIRA, TAKECHI, HIROSHI reassignment NIPPON STEEL CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: SAKAKURA, AKIRA, TAKECHI, HIROSHI
Publication of US20090199935A1 publication Critical patent/US20090199935A1/en
Abandoned legal-status Critical Current

Links

Images

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
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B3/00—Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences ; Rolling of aluminium, copper, zinc or other non-ferrous metals
    • B21B3/02—Rolling special iron alloys, e.g. stainless 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
    • C21D8/1205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties involving a particular fabrication or treatment of ingot or slab
    • 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
    • C21D8/1205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties involving a particular fabrication or treatment of ingot or slab
    • C21D8/1211—Rapid solidification; Thin strip casting
    • 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
    • C21D8/1222—Hot 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
    • C21D8/1216—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
    • C21D8/1255—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 with diffusion of elements, e.g. decarburising, nitriding
    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • C21D9/54—Furnaces for treating strips or wire
    • C21D9/56—Continuous furnaces for strip or wire
    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/70—Furnaces for ingots, i.e. soaking pits
    • 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
    • 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
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • 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
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/46—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting
    • 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
    • C21D2201/00—Treatment for obtaining particular effects
    • C21D2201/05—Grain orientation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/0206—Manufacturing of magnetic cores by mechanical means
    • H01F41/0233—Manufacturing of magnetic circuits made from sheets

Definitions

  • the present invention relates to a method of production of grain-oriented silicon steel sheet superior in magnetic properties, in particular flux density, used for iron core materials for power transformers, iron core materials for rotating equipment, etc.
  • the present invention has as its object the provision of a method of production of high flux density grain-oriented silicon steel sheet able to solve the problems in the conventional method of cooling a thick CC slab once, then heating this slab to a high temperature of 1350° C. or more, able to greatly improve the work efficiency and energy efficiency, and having a more uniform superior crystal grain orientation and Watt loss than the past by using a continuous casting method to produce a medium thickness slab, holding the slab at a hot rollable temperature of the lowest limit or more, holding the AlN already solid-solute in the state of the melt without causing precipitation until continuous hot rolling, and causing fine precipitation by the rapid cooling effect at the time of continuous hot rolling.
  • the present invention is configured as follows:
  • a method of production of high flux density grain-oriented silicon steel sheet characterized by continuously casting a melt containing, by mass, C: 0.010 to 0.075%, Si: 2.95 to 4.0%, acid soluble Al: 0.010 to 0.040%, N: 0.0010 to 0.0150%, and one or both of S and Se in 0.005 to 0.1% and having a balance of Fe and unavoidable impurities to produce a medium-thickness bar of a thickness of 20 to 70 mm, holding the medium thickness bar at a temperature of over 1200° C.
  • a method of production of high flux density grain-oriented silicon steel sheet as set forth in (1) characterized by further including in the melt at least one element selected from the group of Sb: 0.005 to 0.2%, Nb: 0.005 to 0.2%, Mo: 0.003 to 0.1, Cu: 0.02 to 0.2%, and Sn: 0.02 to 0.3% precipitating at grain boundaries to inhibit crystal growth.
  • a method of production of high flux density grain-oriented silicon steel sheet as set forth in (1) characterized by making the medium thickness bar reach the inlet of the final hot rolling mill within 500 seconds at the longest when holding it at a temperature of 1250° C. or more and within 150 seconds when holding it at a temperature of 1200° C. or more.
  • a method of production of high flux density grain-oriented silicon steel sheet as set forth in (1) characterized by heating the medium thickness bar by a heating furnace to hold it at a temperature of 1300 to 1350° C. when the time required for making the medium thickness bar produced by continuous casting reach the inlet of the final hot rolling mill and starting the continuous hot rolling is over 200 seconds or when the temperature of the medium thickness bar is a low temperature such as 1000° C.
  • FIG. 1 is a schematic view of an example of a continuous casting-continuous hot rolling facility.
  • FIG. 2 is a schematic view of another example of a continuous casting-continuous hot rolling facility.
  • FIG. 3 is a view showing the effects of the holding temperature and time after AlN solid solution treatment on the magnetic properties (3.20% Si).
  • FIG. 4 is a view showing typical heat history curves in hot rolling after AlN solid solution treatment (3.10% Si).
  • FIG. 5 is a view showing the relationship between a rapid cooling (tandem rolling) start temperature and magnetic properties in hot rolling after AlN solid solution treatment (3.10% Si).
  • FIG. 6 is a view showing the effects of the amount of Si on the cooling curve and precipitation of AlN after AlN solid solution treatment.
  • C is an element required for causing a certain ⁇ -transformation during hot rolling in accordance with the amount of Si. If less than 0.010%, it is not possible to stably cause secondary recrystallization. Further, if over 0.075%, the decarburization annealing time becomes longer. This is not preferable for production, so the content was made 0.010 to 0.075%.
  • Si is less than 2.95%, a high grade high flux density grain-oriented silicon steel sheet with a superior Watt loss value is not obtained. Further, if added over 4%, cracking occurs at the time of cold rolling due to embrittlement, so this is not preferred. The content was therefore made 2.95 to 4.0%.
  • Acid soluble Al and N are elements required for producing AlN suitable as an inhibitor.
  • the amount sufficient for this purpose was made a range of 0.010 to 0.040% and 0.0010 to 0.0150%.
  • S and Se form MnS and MnSe with Mn which act as precipitated dispersed phases for secondary recrystallization.
  • these are included alone or together in an amount of 0.005% to 0.015%.
  • the bar is hot rolled to a 1.5 mm to 5 mm thick hot rolled sheet, then the sheet is cooled down to 600° C. after the end of the hot rolling within a time of 150 seconds so as to make fine AlN of near 10 nm (5 to 500 nm) precipitate.
  • the thickness of the bar in the present invention is limited to a medium thickness of 20 to 70 mm because if less than 20 mm, a large facility is required for heat retention and, further, if over 70 mm, it is not possible to obtain a hot rolled sheet with just a final rolling mill, that is, a rough rolling mill becomes necessary, and economical production is not achieved.
  • FIG. 1 shows a facility continuously casting a medium thickness slab 2 extracted from a casting mold 1 , loading the cut slab 3 in a heat retaining furnace 4 to hold it at a certain temperature, then immediately rolling it by a final continuous hot rolling mill 5 to obtain a thin hot rolled strip steel 6 and coiling it up.
  • FIG. 2 shows a facility continuous casting a medium thickness slab 2 , then coiling it into a coil 7 , loading the coil into a coil box 8 to even out the temperature, then rolling by a final continuous hot rolling mill 5 and coiling.
  • FIG. 3 and FIG. 4 will be used to explain the processing conditions for a medium thickness bar.
  • a silicon steel ingot containing, by mass %, 0.045% C, 3.20% Si, 0.025% Al, and a balance of Fe and unavoidable impurities was rolled to obtain a 40 mm thick bar as a starting material. This was divided into four pieces which were tested as follows. These were held in a bar heating furnace 1300° C. for 3 hours to make the AlN completely dissolve in the iron metal, then were allowed to cool. When these four types of bars dropped to temperatures of 1250° C., 1210° C., 1100° C., and 1000° C., they were immediately respectively loaded into furnaces held at temperatures of 1250° C., 1210° C., 1100° C., and 1000° C., were respectively held at 1250° C.
  • the curve (A) is the cooling curve in the case of immediately rolling after extraction from the bar heating furnace, while the cooling curves (B), (C), (D), and (E) are as explained above.
  • the hot rolled sheets were cold rolled, decarburized, and final annealed to obtain final products, then the products were measured for magnetic properties (B10).
  • the relationship between these properties and the heat histories is shown in FIG. 3 .
  • the holding time is 0, so the magnetic properties become the most superior B10 properties as shown by the black dots 1 of FIG. 3 .
  • the magnetic properties when performing the hot rolling after holding the sheet at 1000° C. for 20 seconds of FIG. 4(B) , as shown by the white dots 2 of FIG. 3 become considered degraded B10 properties regardless of the holding time being short. If over 100 seconds, the secondary recrystallization itself becomes unstable.
  • the magnetic properties when performing the hot rolling after holding the sheet at 1100° C. for 50 seconds of FIG. 4(C) , as shown by the half black dots 3 of FIG. 3 are improved somewhat due to the long holding time and the high temperature. Furthermore, the magnetic properties when performing the hot rolling after holding the sheet at 1200° C. for 120 seconds of FIG. 4(D) , as shown by the black dots 4 of FIG. 3 , are values close to the best values by making the temperature high even if the holding time is long.
  • the drop in the bar temperature is critical for the B10 properties, but it is learned that if securing a high temperature over 1200° C., a certain margin can be given to the holding time and superior properties can be obtained.
  • FIG. 5 illustrates the relationship between the magnetic properties and the heat history when rolling a silicon steel ingot comprised of 0.046% C, 3.10% Si, 0.029% Al, and a balance of Fe and unavoidable impurities to produce a 40 mm thick bar, immediately rolling it after heating at 1350° C. for 30 minutes to finish it to a 3.5 mm thick hot rolled sheet at about 1000° C., water cooling this from the cooling process right after ending the hot rolling to produce five types of hot rolled sheets, and cold rolling, decarburizing, and final annealing the sheets to produce the final products.
  • the thick lines show the starting point of cooling (water cooling) after hot rolling
  • the thin lines show the magnetic properties (B10).
  • FIG. 6 shows the relationship between the hot rolling and cooling cycle and the amount of precipitation of AlN.
  • the precipitation curve in the case of a low Si (1.12% Si, 2.17% Si) is simultaneously shown.
  • the amount of Si is 3.10%
  • AlN starts to precipitate from around 1250° C. and proceeds rapidly in precipitation at 1200° C. or less.
  • AlN does not proceed much in precipitation at all down to 1000° C. and first starts to precipitate at 1000° C. or less. This is because the ⁇ - ⁇ transformation region of the material changes depending on the amounts of C and Si contained and the precipitation behavior of the AlN is closely related to the amount of this ⁇ -transformation.
  • the cooling after the end of the hot rolling is performed so that at the maximum the time until reaching 600° C. does not exceed 150 seconds.
  • the AlN precipitates due to the cooling from a high temperature, but if taking time and gradually cooling at this time, the AlN will coarsen along with the elapse of time. In extreme cases, it will become a size of about 1 ⁇ m resulting in a state completely meaningless for the object of the present invention. If the AlN in the completely solid-solute state is cooled to 600° C. in a time not exceeding 150 seconds, the precipitated size will become about 10 nm resulting in a state preferable for the present invention.
  • a silicon steel melt comprising, by mass %, 0.045% C, 3.05% Si, and 0.032% Al and having a balance of Fe and unavoidable impurities was cast by a continuous casting machine (hereinafter referred to as a “CC machine”) to a 60 mm thick bar. This was immediately hot rolled by final hot rolling to a thickness of 3.0 mm. The final hot rolling inlet temperature at the bar head part was 1210° C. and at the tail part was 1205° C. The amount of C of the hot rolled sheet was 0.041% whereby slight decarburization occurred. The sheet was first cold rolled at a reduction rate of 30% to a 2.1 mm thickness, then was annealed at 1100° C.
  • the cooling rate was 1100° C. to 850° C. in about 18 seconds and 850° C. to 400° C. in about 27 seconds.
  • the AlN after annealing was analyzed as being 0.0055% (NasAlN).
  • the sheet was cooled by a rolling rate of 83.3% to a thickness of 0.35 mm, then decarburized at 800° C. for 3 minutes in hydrogen, then annealed at 1200° C. for 20 hours.
  • the B10 property in the rolling direction of the product was 1.93 T, and the W17/50 was 1.15 W/kg.
  • Comparative Example A bar of the same ingredients as Example 1 was allowed to stand in front of the final hot rolling mill inlet for about 40 seconds, then started to be final hot rolled.
  • the final rolling start temperature of the bar at that time was 1150° C. at bar head part and 1120° C. at the tail part.
  • the sheet was treated in the same way as Example 1 and the final product was examined for the secondary recrystallized grain formation rate. This was found to be about 50%, that is, a finished product was not formed.
  • a silicon steel melt comprising, by mass %, 0.048% C, 3.13% Si, 0.10% Mn, 0.029% Al, and 0.029% S and having a balance of Fe and unavoidable impurities was cast by a CC machine to a 50 mm thick bar. This was immediately hot, rolled by final hot rolling to a thickness of 2.8 mm. The final hot rolling inlet temperature at the bar head part was 1210° C. and at the tail part was 1200° C. After respectively 10 seconds and 50 seconds, the hot rolling was ended. The temperatures at that time were 1010° C. and 1000° C. After about 75 seconds, the coiling was ended. The C after hot rolling was analyzed as being 0.040% and the AlN 0.0040% (NasAlN).
  • This hot rolled sheet was pickled, then cold rolled by a rolling rate of 87.5% to a final gauge of 0.35 mm, was decarburized at 850° C. for 3 minutes in wet hydrogen, then annealed in hydrogen at 1200° C. for 15 hours.
  • the B10 property in the rolling direction of the product was 1.92 T, and the W17/50 was 1.05 W/kg.
  • a silicon steel melt containing, by mass %, 0.050% C, 3.18% Si, 0.075% Mn, 0.021% Al, and 0.035% S and having a balance of Fe and unavoidable impurities was cast by a CC machine to a 40 mm thick bar and immediately rolled by final hot rolling to a thickness of 3.0 mm.
  • the final hot rolling inlet temperature was 1210° C. at the bar head part and 1205° C. at the tail part.
  • the hot rolling was respectively ended after 12 seconds and after 53 seconds.
  • the temperatures at that time were 1020° C. and 990° C.
  • the coiling was completed after about 80 seconds.
  • Comparative Example A bar of the same ingredients as Example 3 was allowed to stand in front of the final hot rolling mill inlet for about 150 seconds, then started to be final hot rolled.
  • the final rolling start temperature of the bar at that time was 950° C. at the bar head part and 930° C. at the tail part.
  • the sheet was treated under the same way conditions as Example 3 to obtain the final product, then was examined for the secondary recrystallized grain formation rate. This was found to be about 20%, that is, a finished product was not formed.
  • a silicon steel melt containing, by mass %, 0.050% C, 3.12% Si, 0.041% Al, 0.030% S, 0.050% Se, and 0.030% Te and having a balance of Fe and unavoidable impurities was cast by the CC machine to a 60 mm thick bar. This was immediately rolled by final hot rolling to a 3.0 mm thickness.
  • the final hot rolling inlet temperature was 1230° C. at the bar head part and 1210° C. at the tail part.
  • the hot rolling was ended after 15 seconds and after 60 seconds.
  • the temperatures at this time were respectively 1050° C. and 1020° C.
  • the coiling was completed after about 90 seconds.
  • the sheet was continuously annealed at 1100° C. for 2 minutes in a nitrogen atmosphere, then cold rolled by a rate of 50%, then annealed for 1 minute for primary recrystallization and further rolled by a rolling rate of 84.7% to 0.23 mm.
  • the sheet was annealed by decarburization annealing, then by final annealing at 1200° C. for 20 hours along with removal of Se, removal of Te, and removal of S.
  • the magnetic properties of the product were a B10 of 1.93 T and a W17/50 of 1.05 W/kg.
  • a silicon steel melt containing, by mass %, 0.046% C, 3.20% Si, 0.031% Al, and 0.025% S and having a balance of Fe and unavoidable impurities was cast by the CC machine to a 50 mm thick bar. This was immediately rolled by final hot rolling to a 2.5 mm thickness. The final hot rolling inlet temperature was 1220° C. at the bar head part and 1205° C. at the tail part. The hot rolling was ended after 12 seconds and after 50 seconds. The temperatures at this time were respectively 1005° C. and 990° C. The coiling was completed after about 85 seconds.
  • the sheet was continuously annealed at 1130° C. for 2 minutes, then pickled and cold rolled to a final sheet thickness of 0.23 mm, then annealed by decarburization annealing at 850° C. for 2 minutes in wet hydrogen.
  • This steel sheet was coated separately with an annealing separator containing, by ratio of weight with respect to MgO: 100, TiO 2 : 10 and MnO 2 : 5 and furthermore having boric acid added in 0.1 to 3% and with an annealing separator not having boric acid added to it, then was annealed at 1200° C. for 20 hours in hydrogen.
  • a silicon steel melt containing, by mass, 0.04% C, 3.30% Si, and 0.029% Al and having a balance of Fe and unavoidable impurities was cast by the CC machine to a 60 mm thick bar. This was immediately rolled by final hot rolling to a 2.3 mm thickness.
  • the final hot rolling inlet temperature was 1230° C. at the bar head part and 1205° C. at the tail part.
  • the hot rolling was ended after 12 seconds and after 45 seconds.
  • the temperatures at this time were respectively 1010° C. and 995° C.
  • the coiling was completed after about 85 seconds.
  • This hot rolled sheet was continuously annealed at 1150° C. for 2 minutes, rapidly cooled, pickled, and cold rolled to a final sheet thickness of 0.27 mm and annealed by decarburization annealing at 850° C. in hydrogen and by final annealing at 1200° C. It was then cold rolled during and run by the same pass schedule (six passes of 1.6 mm, 1.2 mm, 1.0 mm, 0.8 mm, 0.6 mm, and 0.45 mm) while aging by five different temperatures. That is, the relationship of the conditions and magnetic properties is as shown in Table 2.
  • a silicon steel melt containing, by mass, 0.085% C, 3.20% Si, 0.073% Mn, 0.025% S, 0.025% acid soluble Al, 0.0085% N, 0.08% Sn, and 0.07% Cu and having a balance of Fe and unavoidable impurities was cast by the CC machine to a 60 mm thick bar. This was immediately rolled by final hot rolling to a 2.0 mm thickness. The final hot rolling inlet temperature was 1220° C. at the bar head part and 1201° C. at the tail part. The hot rolling was ended after 15 seconds and after 55 seconds. The temperatures at this time were respectively 990° C. and 985° C. The coiling was completed after about 90 seconds.
  • This hot rolled sheet was continuously annealed at 1130° C. for 2 minutes, then rapidly cooled in hot water of 100° C. and treated by precipitation heat treatment, pickled, then aged at 250° C. ⁇ 5 minutes between passes and cold rolled to a final sheet thickness of 0.22 mm.
  • the sheet was annealed 850° C. for 2 minutes in Craced-NH 3 in an atmosphere of a dew point of 62° C. by decarburization annealing, was coated by an annealing separator containing a mixture of MgO and TiO 2 , and was annealed at 1200° C. by final annealing. It was given a tension coating after the final annealing.
  • a silicon steel melt containing, by mass, 00.05% C, 3.05% Si, 0.07% Mn, 0.03% S, and 0.026% acid soluble Al and having a balance of Fe and unavoidable impurities was cast by the CC machine to a 40 mm thick bar. After the casting, the bar was cut. The temperature of the bar at that time was 0.1255° C. This continued to be held in temperature by a heating apparatus so as not to fall to 1250° C. or less, was made to reach an inlet of a final hot rolling mill in about 300 seconds, and immediately started to be hot rolled to a thickness of 30 mm. The final hot rolling inlet temperature was 1220 to 1230° C. The front end and rear end of the hot rolled sheet were finished being hot rolled in 15 seconds and 60 seconds. The temperatures at the time were 1030° C. and 1020° C. The sheet finished being coiled after about 70 seconds.
  • This hot rolled sheet was continuously annealed at 1130° C. for 3 minutes, then force cooled by immersion in a tank filled with boiling water at the outlet of the furnace, pickled, and cold rolled to a 0.3 mm thickness by a 90% reduction rate. This was then annealed by decarburization annealing, then by final annealing at 1200° C. for 20 minutes in H 2 .
  • Example 8 As a comparative example, a bar of the same ingredients as Example 8 was cast, then conveyed to a final hot rolling mill inlet without holding the temperature by a heating apparatus, whereupon the temperature fell to 1100° C. This was immediately rolled by final hot rolling. The hot rolled sheet was treated under the same conditions as Example 3 to obtain a final product. The final product was examined for the secondary recrystallized grain formation rate. This was found to be about 30%, that is, a finished product was not formed.
  • a silicon steel melt containing, by mass, 0.055% C, 3.20% Si, 0.025% S, and 0.30% acid soluble Al and having a balance of Fe and unavoidable impurities was cast by the CC machine to a 30 mm thick bar. After the casting, the bar was cut. The temperature of the bar at that time was 1150° C. This bar was immediately inserted into a heat furnace heated to 1330° C. to make the side AlN solid-solute, then was taken out from the furnace, made to reach the inlet of a final hot rolling mill in about 120 seconds, and immediately started to be hot rolled to a thickness of 25 mm. The final hot rolling inlet temperature was 1210 to 1220° C. The front end and rear end of the hot rolled sheet were finished being hot rolled in 16 seconds and 50 seconds. The temperatures at the time were 1010° C. and 998° C. The sheet finished being coiled after about 70 seconds.
  • This hot rolled sheet was continuously annealed at 1130° C. for 2 minutes, then force cooled by a mist spraying system at the outlet of the furnace, pickled, cold rolled to a 0.3 mm thickness, then annealed by decarburization annealing at 835° C. for 3 minutes in wet hydrogen.
  • This steel sheet was coated with a slurry of MgO containing 800 ppm of B, was wound in a coil, and was annealed at 1200° C. for 20 hours in hydrogen.
  • Example 8 As a comparative example, a bar of the same ingredients as Example 8 was cast, then immediately conveyed to the inlet of a final hot rolling mill. The temperature further dropped and fell to 1100° C. This was immediately rolled by hot rolling. The hot rolled sheet was treated under the same conditions as Example 3 to obtain a final product. The final product was examined for the secondary recrystallized grain formation rate. Just 20% occurred, that is, a finished product was not formed.
  • the AlN obtained by rapid cooling at the final hot rolling mill (tandem mill) from the completely solid-solute state in the medium thickness cast slab produced by continuous casting is dispersed uniformly and finely. This is sufficient for producing primary recrystallization nuclei having a superior crystal orientation. Simultaneously, the inhibitory effect on crystal growth is also sufficient. Further, the crystal structure obtained by casting is destroyed by the hot rolling. Therefore, it is possible to obtain high flux density grain-oriented silicon steel sheet forming uniform, complete secondary recrystallized grains by the final annealing and having superior properties of a flux density B10>1.90 T without any detrimental effect of abnormally grown grains of the slab due to conventional high temperature heating. Further, high temperature reheating work of 1350° C. by a conventional slab heating furnace is not required at all. The heat held by the steel slab is completely utilized, so leads to remarkable improvement in energy efficiency. The major problem in work due to slab high temperature heating considered difficult in the past can also be solved.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Organic Chemistry (AREA)
  • Metallurgy (AREA)
  • Materials Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Electromagnetism (AREA)
  • Manufacturing & Machinery (AREA)
  • Dispersion Chemistry (AREA)
  • Power Engineering (AREA)
  • Manufacturing Of Steel Electrode Plates (AREA)
  • Soft Magnetic Materials (AREA)
US12/310,769 2006-09-13 2007-06-11 Method of production of high flux density grain-oriented silicon steel sheet Abandoned US20090199935A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2006247674A JP5001611B2 (ja) 2006-09-13 2006-09-13 高磁束密度方向性珪素鋼板の製造方法
JP2006-247674 2006-09-13
PCT/JP2007/062183 WO2008032483A1 (fr) 2006-09-13 2007-06-11 Procédé de fabrication de feuilles d'acier au silicium à grains orientés de haute densité de flux magnétique

Publications (1)

Publication Number Publication Date
US20090199935A1 true US20090199935A1 (en) 2009-08-13

Family

ID=39183552

Family Applications (1)

Application Number Title Priority Date Filing Date
US12/310,769 Abandoned US20090199935A1 (en) 2006-09-13 2007-06-11 Method of production of high flux density grain-oriented silicon steel sheet

Country Status (6)

Country Link
US (1) US20090199935A1 (ja)
EP (1) EP2077164A1 (ja)
JP (1) JP5001611B2 (ja)
KR (1) KR20090057010A (ja)
CN (1) CN101516537A (ja)
WO (1) WO2008032483A1 (ja)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120298224A1 (en) * 2010-01-29 2012-11-29 Toshiba Mitsubishi-Electric Industrial Systems Corporation Water injection controller, water injection control method, and water injection control program for rolling lines
US10889880B2 (en) 2015-03-05 2021-01-12 Jfe Steel Corporation Grain-oriented electrical steel sheet and method for manufacturing same
US11286538B2 (en) 2017-02-20 2022-03-29 Jfe Steel Corporation Method for manufacturing grain-oriented electrical steel sheet

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012089696A1 (en) * 2011-01-01 2012-07-05 Tata Steel Nederland Technology Bv Process to manufacture grain-oriented electrical steel strip and grain-oriented electrical steel produced thereby
WO2014020369A1 (en) 2012-07-31 2014-02-06 Arcelormittal Investigación Y Desarrollo Sl Method of production of grain-oriented silicon steel sheet grain oriented electrical steel sheet and use thereof
CN103805918B (zh) * 2012-11-15 2016-01-27 宝山钢铁股份有限公司 一种高磁感取向硅钢及其生产方法
WO2018084203A1 (ja) * 2016-11-01 2018-05-11 Ｊｆｅスチール株式会社 方向性電磁鋼板の製造方法
CN109906277B (zh) * 2016-11-01 2021-01-15 杰富意钢铁株式会社 取向性电磁钢板的制造方法
CN112391512B (zh) * 2019-08-13 2022-03-18 宝山钢铁股份有限公司 一种高磁感取向硅钢及其制造方法
WO2024204818A1 (ja) 2023-03-29 2024-10-03 Ｊｆｅスチール株式会社 方向性電磁鋼板の製造方法、方向性電磁鋼板の製造設備列、及び方向性電磁鋼板用熱延板

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1965559A (en) * 1933-08-07 1934-07-03 Cold Metal Process Co Electrical sheet and method and apparatus for its manufacture and test
US3159511A (en) * 1956-11-08 1964-12-01 Yawata Iron & Steel Co Process of producing single-oriented silicon steel
US4437909A (en) * 1981-05-30 1984-03-20 Nippon Steel Corporation Process for producing a grain-oriented silicon steel sheet or strip having excellent magnetic properties
US6309473B1 (en) * 1998-10-09 2001-10-30 Kawasaki Steel Corporation Method of making grain-oriented magnetic steel sheet having low iron loss
US20020033206A1 (en) * 1996-12-24 2002-03-21 Stefano Cicale' Process for the production of oriented-grain electrical steel sheet with high magnetic characteristics
US20050098235A1 (en) * 2000-08-09 2005-05-12 Fortunati Stefano S. Process for the control of inhibitors distribution in the production of grain oriented electrical steel strips

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02121704A (ja) * 1988-11-01 1990-05-09 Nkk Corp 電磁鋼板の熱間圧延方法
JPH02258922A (ja) 1989-03-30 1990-10-19 Nippon Steel Corp 一方向性高磁束密度電磁鋼板の製造方法
JP2580403B2 (ja) 1991-05-17 1997-02-12 新日本製鐵株式会社 一方向性電磁鋼板用連続鋳造スラブの熱間圧延方法
JP2000500568A (ja) 1995-11-17 2000-01-18 ユニバーサル ヘルスウォッチ、インコーポレーテッド 分析対象物の検出に用いる化学発光分析方法及び分析装置

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1965559A (en) * 1933-08-07 1934-07-03 Cold Metal Process Co Electrical sheet and method and apparatus for its manufacture and test
US3159511A (en) * 1956-11-08 1964-12-01 Yawata Iron & Steel Co Process of producing single-oriented silicon steel
US4437909A (en) * 1981-05-30 1984-03-20 Nippon Steel Corporation Process for producing a grain-oriented silicon steel sheet or strip having excellent magnetic properties
US20020033206A1 (en) * 1996-12-24 2002-03-21 Stefano Cicale' Process for the production of oriented-grain electrical steel sheet with high magnetic characteristics
US6309473B1 (en) * 1998-10-09 2001-10-30 Kawasaki Steel Corporation Method of making grain-oriented magnetic steel sheet having low iron loss
US20050098235A1 (en) * 2000-08-09 2005-05-12 Fortunati Stefano S. Process for the control of inhibitors distribution in the production of grain oriented electrical steel strips

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120298224A1 (en) * 2010-01-29 2012-11-29 Toshiba Mitsubishi-Electric Industrial Systems Corporation Water injection controller, water injection control method, and water injection control program for rolling lines
US9180505B2 (en) * 2010-01-29 2015-11-10 Toshiba Mitsubishi-Electric Industral Systems Corporation Water injection controller, water injection control method, and water injection control program for rolling lines
US10889880B2 (en) 2015-03-05 2021-01-12 Jfe Steel Corporation Grain-oriented electrical steel sheet and method for manufacturing same
US11286538B2 (en) 2017-02-20 2022-03-29 Jfe Steel Corporation Method for manufacturing grain-oriented electrical steel sheet

Also Published As

Publication number Publication date
CN101516537A (zh) 2009-08-26
WO2008032483A1 (fr) 2008-03-20
EP2077164A1 (en) 2009-07-08
KR20090057010A (ko) 2009-06-03
JP5001611B2 (ja) 2012-08-15
JP2008069391A (ja) 2008-03-27

Similar Documents

Publication Publication Date Title
US20090199935A1 (en) Method of production of high flux density grain-oriented silicon steel sheet
US9831020B2 (en) Method of production of grain-oriented silicon steel sheet grain oriented electrical steel sheet and use thereof
HUP0004822A2 (hu) Eljárás szemcseorientált elektroacél minőségű lemezanyag előállítására kis mágnesezési veszteséggel és nagy polarizációval
JP5782527B2 (ja) 低鉄損高磁束密度方向性電気鋼板及びその製造方法
US5330586A (en) Method of producing grain oriented silicon steel sheet having very excellent magnetic properties
JPS5813606B2 (ja) ジキトクセイノ キワメテ スグレタ イツホウコウセイケイソコウタイバンノ セイゾウホウホウ
KR100831756B1 (ko) 그레인 방향성 전기 강 스트립의 제조시 억제제 분포를조절하는 방법
JP3357603B2 (ja) 極めて鉄損の低い高磁束密度方向性電磁鋼板の製造方法
JPH0463228A (ja) 磁性焼鈍前後の磁気特性の優れた無方向性電磁鋼板の製造方法
JPH08269552A (ja) 超高磁束密度一方向性電磁鋼板の製造方法
JP4258156B2 (ja) 方向性電磁鋼板およびその製造方法
JP2607331B2 (ja) 磁気特性の優れた一方向性電磁鋼板の製造方法
JP3928275B2 (ja) 電磁鋼板
JP2784687B2 (ja) 磁気特性の優れた一方向性電磁鋼板の製造方法
JP6228956B2 (ja) 低鉄損高磁束密度方向性電気鋼板及びその製造方法
JP7264322B1 (ja) 方向性電磁鋼板の製造方法
JPH0699750B2 (ja) 電磁特性の良好な方向性けい素鋼板の製造方法
KR100240989B1 (ko) 고자속밀도급 방향성 전기강판의 제조방법
JPH05230534A (ja) 磁気特性の優れた一方向性電磁鋼板の製造方法
KR100940714B1 (ko) 응력제거소둔 후 철손특성이 우수한 무방향성 전기강판의제조방법
KR100256343B1 (ko) 저온 스라브 가열방식에의한 방향성 전기강판의 제조방법
TW202532661A (zh) 無方向性電磁鋼板用熱軋鋼板的製造方法及無方向性電磁鋼板的製造方法
CN120917159A (zh) 取向性电磁钢板的制造方法、取向性电磁钢板的制造设备线和取向性电磁钢板用热轧板
KR20000041670A (ko) 피막특성이 우수한 저온 슬라브가열 방식의 방향성 전기강판제조방법
JPH04362138A (ja) 磁気特性の優れた厚い板厚の一方向性電磁鋼板の製造方法

Legal Events

Date Code Title Description
AS Assignment

Owner name: TAKECHI, HIROSHI, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SAKAKURA, AKIRA;TAKECHI, HIROSHI;REEL/FRAME:022387/0908

Effective date: 20090203

Owner name: SAKAKURA, AKIRA, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SAKAKURA, AKIRA;TAKECHI, HIROSHI;REEL/FRAME:022387/0908

Effective date: 20090203

Owner name: NIPPON STEEL CORPORATION, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SAKAKURA, AKIRA;TAKECHI, HIROSHI;REEL/FRAME:022387/0908

Effective date: 20090203

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION