EP4634425A1 - Acier électrique non orienté et procédé de fabrication d'un acier électrique non orienté correspondant - Google Patents

Acier électrique non orienté et procédé de fabrication d'un acier électrique non orienté correspondant

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Publication number
EP4634425A1
EP4634425A1 EP22830614.8A EP22830614A EP4634425A1 EP 4634425 A1 EP4634425 A1 EP 4634425A1 EP 22830614 A EP22830614 A EP 22830614A EP 4634425 A1 EP4634425 A1 EP 4634425A1
Authority
EP
European Patent Office
Prior art keywords
steel sheet
oriented electrical
electrical steel
anyone
temperature
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.)
Pending
Application number
EP22830614.8A
Other languages
German (de)
English (en)
Inventor
Wahib SAIKALY
Bruno Michel
Lisa LASTRA
Elvan EKIZ
Alix ASSELIN
Xavier Bano
Emmanuel Joubert
Martin LIEBEHERR
Lode VANDENBOSSCHE
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.)
ArcelorMittal SA
Original Assignee
ArcelorMittal SA
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 ArcelorMittal SA filed Critical ArcelorMittal SA
Publication of EP4634425A1 publication Critical patent/EP4634425A1/fr
Pending legal-status Critical Current

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    • 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
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/26—Methods of annealing
    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/008—Heat treatment of ferrous alloys containing Si
    • 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 of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/12—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
    • C21D8/1205—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties involving particular fabrication steps or treatments of ingots or slabs
    • 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 of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/12—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
    • C21D8/1216—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties characterised by the working steps
    • 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 of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/12—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
    • C21D8/1216—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties characterised by the working steps
    • 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 of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/12—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
    • C21D8/1244—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties characterised by the heat treatment
    • C21D8/1261—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties characterised by the heat treatment following 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 of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/12—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
    • C21D8/1244—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties characterised by the heat treatment
    • C21D8/1272—Final recrystallisation annealing
    • 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
    • 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
    • C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
    • 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
    • C22C38/008—Ferrous alloys, e.g. steel alloys containing tin
    • 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
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • 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
    • 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
    • C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
    • 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
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • 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
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
    • 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
    • C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/34—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • 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
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
    • C23G1/08—Iron or steel
    • 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
    • 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
    • H01F1/14791—Fe-Si-Al based alloys, e.g. Sendust
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite

Definitions

  • the present invention relates to a non-oriented electrical steel sheet and a manufacturing method thereof. Specifically, the present invention relates to a non-oriented electrical steel sheet and a manufacturing method thereof that have similar mechanical properties in both transverse and rolling direction at the same time while having improved magnetic properties such as polarization.
  • EP2883975 is a high-strength electrical steel sheet that is suitable as rotor material for a high speed motor, steadily has high strength, and also has excellent magnetic properties can be obtained by setting the chemical composition thereof to include, by mass%, C: 0.005 % or less, Si: more than 3.5 % and 4.5 % or less, Mn: 0.01 % or more and 0.10 % or less, Al: 0.005 % or less, Ca: 0.0010 % or more and 0.0050 % or less, S: 0.0030 % or less, and N: 0.0030 % or less, Ca/S being 0.80 or more, the balance being Fe and incidental impurities, and by setting the sheet thickness to 0.40 mm or less, the non-recrystallized deformed microstructure to 10 % or more and 70 % or less, tensile strength (TS) to 600 MPa or more, and iron loss W MOO to 30 W/kg or less.
  • TS tensile strength
  • EP3875612 is a non-oriented electrical steel sheet having a predetermined chemical composition satisfying the expression [Si + 0.5 x Mn > 4.3], and an average grain size of the base metal is more than 40 pm and 120 pm or less. EP3875612is not able to demonstrate the tensile and yield strength properties in both transverse and rolling direction.
  • the purpose of the present invention is to solve these problems by making non-oriented electrical steel sheets that simultaneously have:
  • such steel can also have a good suitability for rolling with good weldability and coatability.
  • Another object of the present invention is also to make available a method for the manufacturing of these sheets that is compatible with conventional industrial applications while being robust towards manufacturing parameters shifts.
  • the chemical composition of the non-oriented electrical steel comprises of the following elements:
  • Carbon is present in the steel of present invention is from 0.0001% to 0.008%. Carbon is a precipitate forming element that is why detrimental for the magnetic properties of the present steel. Hence the presence of Carbon in the present steel is from 0.0001% to 0.008%. Since the Carbon promotes magnetic aging the preferred content of Carbon according to the present invention is from 0.0001 % to 0.006% and more preferably from 0.0001 % to 0.005%.
  • Manganese content of the steel of present invention is from 0.1% to 1.2%. Manganese provides solid solution strengthening and reducing the iron loss by increasing specific resistance. When the addition of manganese amount is above 1 .2%, the magnetic flux density may be considerably reduced, and recrystallization of the steel will be hindered during annealing.
  • the preferred limit for the presence of Manganese is from 0.1 % to 1.1 % and more preferably from 0.1 % to 1.05%.
  • Silicon content of the steel of present invention is from 2.8% to 3.5%.
  • Silicon is an element that contributes to increasing the strength by solid solution strengthening and is a key element to reduce eddy current loss of iron loss by increasing specific resistance of steel.
  • the mentioned effects requires a minimum Silicon content of at least 2.8%.
  • silicon content is in an amount exceeding 3.5% causes the rolling to be difficult and the magnetic induction of the steel will be significantly lowered.
  • the preferred limit for the presence of Silicon is from 2.9% to 3.4% and more preferably from 3% to 3.4%.
  • Sulfur is not an essential element but may be contained as an impurity in steel and from point of view of the present invention the Sulfur content is preferably as low as possible but 0.006% or less from the viewpoint of manufacturing cost. Further if higher Sulfur is present in steel it combines to form Sulfides which are detrimental for the magnetic properties of the present invention.
  • Cobalt is an element increasing the magnetic moment of Fe alloy and has an effect of increasing a magnetic flux density and reducing the iron loss.
  • the addition amount is less than 0.01 wt.%, the above effects cannot be obtained sufficiently, while when it exceeds 1 wt.%, the raw material cost is largely increased.
  • the above effect is obtained by the addition of not less than 0.001 wt.%.
  • Copper may be added as an optional element in an amount of 0% to 1% to increase the strength and elongation of the of Steel of present invention. However, when its content is above 1 %, it can degrade the surface aspects.
  • Boron is an optional element for the steel of present invention and may be present between 0% and 0.05%. Boron forms boro-nitirides and impart additional strength to steel of present invention when added in an amount of at least 0.0001 %.
  • Calcium may be present in the steel of present invention optionally and may be from 0.001% to 0.01 %%. Calcium contributes towards the refining of the Steel by binding the detrimental Sulfur content in globular form thereby retarding the harmful effect of Sulfur.
  • Sn , Pb or Sb can be added individually or in combination in the following proportions: Sn ⁇ 0.2%, Pb ⁇ 0.2% and Sb ⁇ 0.2%. Up to the maximum content levels indicated, these elements make it possible to refine the grain during solidification. The remainder of the composition of the steel consists of iron and inevitable impurities resulting from processing.
  • the non-oriented electrical steel sheet according to the invention mandatorily contains Silicon, Manganese and Aluminum such that the total content is from 3.5% to 5.5wt.%.
  • Si, Mn and Al When the total content of Si, Mn and Al is less than 3.5%, it is not possible to achieve the mechanical properties in both transverse and rolling direction along with the magnetic properties. However, when the total content of Si , Mn and Al exceeds 5.5%, steel is hardened and the rolling becomes difficult.
  • the microstructure of the non-oriented electrical steel will now be described in detail, all percentages being in area fraction.
  • the microstructure is made of ferrite.
  • the steel of present invention has a recrystallized microstructural region from 80% to 100% in area fraction with grains having an average grain size from 20 microns to 50 microns.
  • the recrystallized structure with a high degree of recrystallization is due to the homogenous Silicon enrichment which improves magnetic properties of the steel of present invention.
  • a controlled grain size ensures the mechanical properties in both transverse and rolling direction.
  • the preferred degree of recrystallization is from 90% to 100%.
  • the preferred an average grain size for the present invention is from 20 microns to 45 microns and more preferably from 20 microns to 40 microns.
  • the steel of present invention may have a non-recrystallized microstructural region from 0% to 20% in area fraction and the preferred degree of recrystallization is from 0% to 10% and more preferably from 0% to 5%
  • the microstructure of the non-oriented electrical steel is free from microstructural components such as martensite, bainite, pearlite and cementite.
  • the steel according to the invention can be manufactured by any suitable methods. It is however preferable to use the method according to the invention that will be detailed, as a non-limitative example.
  • Such preferred method consists in providing a semi-finished casting of steel with a chemical composition of the steel according to the invention.
  • the casting can be done either into ingots or continuously in form of thin slabs or thin strips, i.e. with a thickness ranging from approximately 220mm for slabs up to several tens of millimeters for thin strip.
  • the cast in form of a slab is casted with the chemical composition according to the invention and then it is reheated, the Slab Reheating Temperature lying between 1050°C and 1250°C until the temperature is homogeneous through the whole slab. Below 1050°C, rolling becomes difficult and forces on the mill will be too high. Above 1250°C, high silicon grades become very soft and might show some sagging and thus become difficult to handle. Subjecting the reheated slab to hot rolling wherein the hot rolling finishing temperature plays a role on the final hot rolled microstructure and takes place from 750°C to 950°C. When the Finishing Rolling Temperature is below 750°C, recrystallization is limited and the microstructure is highly deformed. Above 950°C would mean more impurities in solid solution and possible consequent precipitation and deterioration of magnetic properties as well.
  • the hot rolled steel sheet obtained in this manner is then cooled immediately at a cooling rate of at least 10°C/s to the Coiling Temperature of the hot rolled steel sheet which also plays a role on the hot rolled steel sheet; it takes place between 500°C and 750°C. Coiling at temperatures below 500°C would not allow sufficient recovery to take place while this metallurgical step is necessary for magnetic properties. Above 750°C, a thick oxide layer would appear, and it will cause difficulties for subsequent processing steps such as cold rolling and/or pickling.
  • the cooling rate will be less than or equal to 200° C/s.
  • the coiled hot rolled steel sheet is then cooled down to room temperature before subjecting it to optional hot band annealing.
  • the hot rolled steel sheet may be subjected to an optional scale removal step to remove the scale formed during the hot rolling before optional hot band annealing.
  • the hot rolled sheet then be subjected to an optional hot band annealing such hot band annealing is performed at temperatures from 650°C to 1100°C, preferably for at least 10 seconds and not more than 96 hours, the temperature preferably remaining from 700°C to 1070°C and more preferably from 720°C to 1050°C.
  • an optional scale removal step of this hot rolled steel sheet may be performed through, for example, pickling of such sheet.
  • This hot rolled steel sheet is then subjected to cold rolling to obtain a cold rolled steel sheet with a thickness reduction between 35 to 90%.
  • the cold rolled steel sheet is then heated wherein the heating starts from room temperature, the cold rolled steel sheet being heated, at a heating rate HR1 of at least 1 °C/s, to an annealing temperature Tsoak which is from 800°C to 875°C, preferably from 810°C to 865°C.
  • the heating rate HR1 for heating is at least 2°C/s and more preferably at least 5°C/s.
  • the cold rolled steel sheet is held at Tsoak during 10 seconds to 5000 seconds to ensure a recrystallization between 80% and 100%.
  • the cold rolled steel sheet is then cooled wherein cooling starts from Tsoak, the cold rolled steel sheet being cooled down, at a cooling rate CR1 from 1°C/s to 150°C/s, to a temperature T 1 which is in a range from 20°C to 300°C.
  • the cooling rate CR1 is from 3°C/s to 120°C/s.
  • the preferred T1 temperature is from 20°C to 200°C.
  • the cold rolled steel sheet is cooled down to room temperature to obtain a non-oriented electrical steel sheet.
  • the non-oriented electrical steel sheet of the present invention may optionally be coated with insulation, organic coating or inorganic coating or combination of both to improve isolation.
  • Table 1 Steel sheets made of steels with different compositions are gathered in Table 1 , where the steel sheets are produced according to process parameters as stipulated in Table 2, respectively. Thereafter Table 3 gathers the microstructures of the steel sheets obtained during the trials and table 4 gathers the result of evaluations of obtained properties.
  • Table 2 gathers the hot rolling and annealing process parameters implemented on cold rolled steel sheets to impart the steels of table 1 with requisite mechanical and magnetic properties to become a non-oriented electrical steel.
  • the table 2 is as follows:
  • Table 3 exemplifies the results of the tests conducted in accordance with the standards on different microscopes such as Scanning Electron Microscope for determining the microstructures of both the inventive and reference steels in terms of area fraction and the grain size for both inventive and reference example is measured as per the ASTM E112 standards with linear intercept method. The results are stipulated herein:
  • Table 4 The results of the various mechanical tests conducted in accordance with the standards are gathered. For testing the ultimate tensile strength and yield strength are tested in accordance with NF EN ISO 6892-1 standards and the J50 magnetic properties were measured in accordance of NF EN 60404-2 standards.

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  • Chemical & Material Sciences (AREA)
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  • Organic Chemistry (AREA)
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  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Soft Magnetic Materials (AREA)
  • Manufacturing Of Steel Electrode Plates (AREA)
  • Manufacture Of Motors, Generators (AREA)

Abstract

Feuille d'acier électrique non orienté présentant une composition comprenant les éléments suivants : 0,0001 % ≤ carbone ≤ 0,008 %, 0,1 % ≤ manganèse ≤ 1,2 %, 2,8 % ≤ silicium ≤ 3,5 %, 0,4 % ≤ aluminium ≤ 1,2 %, 0 % ≤ phosphore ≤ 0,15 %, 0 % ≤ soufre ≤ 0,006 %, 0 % ≤ nitrogène ≤ 0,09 %, avec 3,5 % ≤ Si + Al + Mn ≤ 5,5 %, 0 % ≤ niobium ≤ 0,1 %, 0 % ≤ titane ≤ 0,1 %, 0 % ≤ vanadium ≤ 0,1 %, 0 % ≤ chrome ≤ 1 %, 0 % ≤ molybdène ≤ 0,5 %, 0 % ≤ tungstène ≤ 0,1 %, 0 % ≤ cobalt ≤ 1 %, 0 % ≤ arsenic ≤ 0,05 %, 0,001 % ≤ calcium ≤ 0,01 %, 0 % ≤ cuivre ≤ 1 %, 0 % ≤ nickel ≤ 1 %, 0 % ≤ bore ≤ 0,05 %, 0 % ≤ plomb ≤ 0,2 %, 0 % ≤ étain ≤ 0,2 %, 0 % ≤ antimoine ≤ 0,2 %, la composition restante étant composée de fer et d'impuretés inévitables dues au traitement, la microstructure de ladite feuille d'acier étant constituée de ferrite et comprenant, en fraction de surface, de 80 % à 100 % d'une microstructure recristallisée et de 0 % à 20 % d'une microstructure non recristallisée, la taille moyenne de grain de la microstructure recristallisée étant de 20 microns à 50 microns.
EP22830614.8A 2022-12-15 2022-12-15 Acier électrique non orienté et procédé de fabrication d'un acier électrique non orienté correspondant Pending EP4634425A1 (fr)

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JPH09157804A (ja) * 1995-12-11 1997-06-17 Nkk Corp 低磁場での磁気特性に優れ、磁気異方性が小さい無方向性電磁鋼板およびその製造方法
CN104532119B (zh) * 2009-09-03 2018-01-02 新日铁住金株式会社 无方向性电磁钢板的制造方法
CN104520458B (zh) 2012-08-08 2017-04-12 杰富意钢铁株式会社 高强度电磁钢板及其制造方法
KR101728827B1 (ko) * 2015-12-24 2017-04-20 주식회사 포스코 무방향성 전기강판 및 그 제조방법
WO2018025941A1 (fr) * 2016-08-05 2018-02-08 新日鐵住金株式会社 Feuille d'acier électromagnétique non orientée, procédé de production d'une feuille d'acier électromagnétique non orientée et procédé de production d'un noyau de moteur
KR102120276B1 (ko) * 2018-09-27 2020-06-08 주식회사 포스코 무방향성 전기강판 및 그 제조방법
CN112930412A (zh) * 2018-10-31 2021-06-08 杰富意钢铁株式会社 无取向性电磁钢板及其制造方法以及电动机铁心及其制造方法
JP7143901B2 (ja) 2018-11-02 2022-09-29 日本製鉄株式会社 無方向性電磁鋼板
JP6744601B1 (ja) * 2018-12-27 2020-08-19 Ｊｆｅスチール株式会社 無方向性電磁鋼板
JP7192887B2 (ja) * 2019-01-17 2022-12-20 日本製鉄株式会社 無方向性電磁鋼板、分割型固定子および回転電機

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MX2025006802A (es) 2025-07-01
CN120283072A (zh) 2025-07-08
KR20250110868A (ko) 2025-07-21
JP2025540853A (ja) 2025-12-16

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