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EP-4739806-A1 - NON-GRAIN-ORIENTED METAL ELECTRICAL STRIP OR SHEET, METHOD FOR PRODUCING A NON-GRAIN-ORIENTED ELECTRICAL STRIP, AND USE

EP4739806A1EP 4739806 A1EP4739806 A1EP 4739806A1EP-4739806-A1

Abstract

The invention relates to a non-grain-oriented metal electrical strip or sheet which is characterized, in addition to its alloy composition, by a thickness of < 0.270 mm and a 0.2% proof stress Rp0.2 > 420 MPa. Another aspect of the invention relates to a method for producing a non-grain-oriented electrical strip and to a use.

Inventors

  • Vidovic, Anton
  • STRECKER, Nina Maria
  • FISCHER, OLAF
  • MATOS COSTA, Aleksander
  • MACHALITZA, Karsten
  • LÜBKE, Jan

Assignees

  • ThyssenKrupp Steel Europe AG

Dates

Publication Date
20260513
Application Date
20240503

Claims (20)

  1. 1. Non-grain-oriented metallic electrical strip or sheet, consisting of the following components, each in percent by weight, in short: % by weight: C: 0.0005 up to 0.0040, preferably 0.0005 up to 0.0035; Si: 2.8 up to 3.2, preferably 2.9 up to 3.1; Al: 1.3 up to 1.7, preferably 1.40 up to 1.60; Mn: 0.5 to 0.7, preferably 0.55 to 0.65; P: up to 0.040, preferably up to 0.020; S: up to 0.0030, preferably up to 0.0010; N : up to 0.0030; Ti: up to 0.0070, preferably up to 0.0040; Mo+Nb+V+Zr+Sb+Sn+Cu+Cr+Ni: up to 0.1; Remainder Fe and unavoidable impurities, characterized in that the electrical strip or sheet has a thickness < 0.270 mm, preferably < 0.260 mm, and a 0.2% yield strength Rp0.2 > 420 MPa.
  2. 2. Electrical strip or sheet according to claim 1, wherein C: 0.0005 up to 0.0035; Si: 2.9 up to 3.1, preferably 2.9 up to 3.0; Al: 1.40 up to 1.60; Mn: 0.55 to 0.65; P: up to 0.040, preferably up to 0.020; S: up to 0.0030, preferably up to 0.0010; N : up to 0.0030; Ti: up to 0.0070, preferably up to 0.0040; Mo+Nb+V+Zr+Sb+Sn+Cu+Cr+Ni : up to 0.1; Rest Fe and unavoidable impurities.
  3. 3. Electrical strip or sheet according to claim 1 or Claim 2, wherein C: 0.0025 up to 0.0035, preferably 0.0027 up to 0.0033; Si: 2.9 up to 3.1, preferably 2.9 up to 3.0; Al: 1.40 up to 1.60; Mn: 0.55 to 0.65; P: up to 0.040, preferably up to 0.020; S: up to 0.0030, preferably up to 0.0010; N : up to 0.0030; Ti: up to 0.0040; Mo+Nb+V+Zr+Sb+Sn+Cu+Cr+Ni : up to 0.1; Rest Fe and unavoidable impurities.
  4. 4. Electrical strip or sheet according to one of the preceding claims, wherein Al/(Si + Al) has a value between 0.30 and 0.40, preferably between 0.30 and 0.35.
  5. 5. Electrical strip or sheet according to one of the preceding claims, wherein the thickness of the electrical strip or sheet is between 0.180 mm and 0.270 mm, preferably between 0.230 mm and 0.270 mm, particularly preferably between 0.235 mm and 0.250 mm.
  6. 6. Electrical strip or sheet according to one of the preceding claims, wherein the electrical strip or sheet has a 0.2% proof stress Rp0.2 with 430 MPa < Rp0.2 < 470 MPa and/or an A8 O elongation at break of more than 14%, preferably more than 15%.
  7. 7. Electrical strip or sheet according to one of the preceding claims, wherein it has core loss values P (1,0T; 400Hz) < 13.00 W/kg, preferably P (1,0T; 400Hz) < 12.40 W/kg, particularly preferably P (1,0T; 400Hz) < 12.30 W/kg, and/or it has core loss values P (1,0T; 2000Hz) < 150.00 W/kg, preferably P(1,OT; 2000Hz) < 145.00 W/kg, particularly preferably P(1,OT; 2000Hz) < 143.00 W/kg.
  8. 8. Electrical strip or sheet according to one of the preceding claims, wherein it has a magnetic polarization J100;50Hz > 0.910 T, preferably J100;50Hz > 0.930 T, and/or it has a magnetic polarization J2500;50Hz >= 1,510 T, preferably J2500;50Hz >= 1,520 T.
  9. 9. Electrical strip or sheet according to one of the preceding claims, having a specific electrical resistance between 0.59 pQm and 0.70 pQm at a temperature of 25 degrees Celsius.
  10. 10. Process for producing a non-grain-oriented electro bands, comprising at least the following Process steps: (A) providing a hot-rolled and hot-strip annealed, non-grain-oriented electrical steel strip having a thickness between 1.6 mm and 2.2 mm, preferably between 1.8 mm and 2.1 mm; (B) cold rolling the electrical steel strip provided in step (A) to a thickness of between 0.180 mm and 0.270 mm; (C) final annealing and cooling the cold strip obtained in step (B) to obtain the non-grain oriented electrical steel strip, wherein the final annealing is carried out in a continuous furnace.
  11. 11. The method according to claim 10, wherein during the final annealing the specific infeed belt tension is at most 5 N/mm 2 , preferably at most 2.5 N/mm 2 , particularly preferably at most 2.3 N/mm 2 , and/or the specific outfeed belt tension is at most 4 N/mm 2 , preferably at most 3.5 N/mm 2 , particularly preferably at most 2.5 N/mm 2 .
  12. 12. Method according to claim 10 or claim 11, characterized in that in the final annealing during a high annealing period, a high annealing temperature is between 1010 degrees Celsius and 1090 degrees Celsius, preferably between 1020 degrees Celsius and 1080 degrees Celsius, particularly preferably between 1030 degrees Celsius and 1070 degrees Celsius.
  13. 13. A method according to claim 12, characterized in that the final annealing (CI) is heated at a heating rate of at least 40 K/s to a temperature between 850 degrees Celsius and 950 degrees Celsius, preferably between 880 degrees Celsius and 920 degrees Celsius, and thereafter (C2) is heated to the annealing temperature at a heating rate between 5 and 150 K/s.
  14. 14. The method according to claim 12 or claim 13, characterized in that the annealing period is a period of 10 seconds to 90 seconds.
  15. 15. The method according to any one of claims 10 to 14, characterized in that the cooling of the cold strip in step (C) to room temperature is carried out at a maximum cooling rate of 25 K/s.
  16. 16. A method according to any one of claims 10 to 15, characterized in that the annealing of step (C) - in an annealing atmosphere with at least 60 vol. percent H2, preferably at least 70 vol. percent H2 and/or - is carried out at a dew point of Tp < 5 degrees Celsius, preferably a dew point of Tp < 0 degrees Celsius.
  17. 17. Process according to one of claims 10 to 16, characterized in that the electrical steel provided in step (A) consists of: the following components, each in percent by weight, in short: % by weight: C: 0.0005 up to 0.0040, preferably 0.0005 up to 0.0035; Si: 2.8 up to 3.2, preferably 2.9 up to 3.1; Al: 1.3 up to 1.7, preferably 1.40 up to 1.60; Mn: 0.5 to 0.7, preferably 0.55 to 0.65; P: up to 0.040, preferably up to 0.020; S: up to 0.0030, preferably up to 0.0010; N : up to 0.0030; Ti: up to 0.0070, preferably up to 0.0040; Mo+Nb+V+Zr+Sb+Sn+Cu+Cr+Ni: up to 0.1; Balance Fe and unavoidable impurities; preferably with a content of the sum of C, S, N and Ti of maximum 0.0100 wt.%.
  18. 18. Method according to one of claims 10 to 17, characterized in that the electrical steel provided in step (A) consists of: the following components, each in percent by weight, in short: % by weight: C: 0.0025 up to 0.0035, preferably 0.0027 up to 0.0033; Si: 2.9 up to 3.1, preferably 2.9 up to 3.0; Al: 1.40 up to 1.60; Mn: 0.55 to 0.65; P: up to 0.040, preferably up to 0.020; S: up to 0.0030, preferably up to 0.0010; N : up to 0.0030; Ti: up to 0.0040; Mo+Nb+V+Zr+Sb+Sn+Cu+Cr+Ni : up to 0.1; Rest Fe and unavoidable impurities.
  19. 19. The method according to any one of claims 10 to 18, characterized in that the cold rolling in step (B) is carried out to a thickness between 0.180 mm and 0.270 mm, preferably between 0.230 mm and 0.270 mm, particularly preferably between 0.235 mm and 0.250 mm.
  20. 20. Electrical steel obtainable by a process according to one of claims 10 to 19.

Description

Non-grain-oriented metallic electrical steel strip or sheet, process for producing a non-grain-oriented electrical steel strip and use The invention relates to non-grain-oriented metallic electrical steel strip or sheet. The invention also relates to a method for producing a non-grain-oriented electrical steel strip and to a use thereof. Non-grain-oriented flat products, in particular non-grain-oriented electrical steel strip or sheet, are required in many electrical engineering applications and are known from practice. Non-grain-oriented electrical steel or strip, often referred to as "NO electrical steel" or "NO electrical sheet", or in English as "NGO electrical steel" ("NGO" = Non Grain Oriented), is used, for example, as a starting material for the manufacture of components of a rotating electrical machine. The non-grain-oriented electrical steel or strip is used to guide and amplify electromagnetic fields. Typical applications for such steel strips and sheets are rotors and stators in electric motors and electric generators. For many electric motors, operation at high speeds per unit of time is desired, for example in motors that are being developed for applications in the context of so-called electromobility and are therefore becoming increasingly important. The operation of an electric motor at high speeds is accompanied by high frequencies of the required alternating electromagnetic field, which ultimately forms the basis for driving the motor. Therefore, materials are increasingly required that are designed for use in alternating electromagnetic fields with comparatively high frequencies. When developing electric motors for operation in high-frequency alternating fields, the material developer is faced with the challenge of making a contribution to increasing the efficiency of the electric motor. Against this background, non-grain-oriented metallic flat products are required, in particular non-grain-oriented electrical steel and non-grain-oriented electrical sheet, which combine comparatively low remagnetization losses at comparatively high frequencies with comparatively high magnetic polarization and induction as well as comparatively high permeability, in particular in the relevant ranges of the magnetic field strength, i.e. at comparatively low magnetic field strengths. A further challenge that arises when looking for suitable materials lies in the planned application in high-frequency electromagnetic alternating fields, which are often accompanied by rotary movements at high rotation frequencies: In order to be able to withstand the resulting mechanical loads for a sufficiently long time, the materials must be sufficiently strong, in particular a sufficiently high 0.2% yield strength. This presents a particular difficulty, particularly with regard to the alloy composition to be found, since measures to improve high-frequency suitability are often accompanied by a deterioration in strength. Good combinations of these properties are achieved in proven electrical strips and sheets by a comparatively high weight proportion of the alloy components silicon and/or aluminum in the starting alloy of the electrical strip or sheet. However, high contents of these elements are usually associated with the disadvantageous effect that corresponding previously known NO electrical strips or NO electrical steel sheets are comparatively brittle due to their high silicon and/or aluminum content, with the associated disadvantages in terms of processability, e.g. in cold rolling. For example, when cold rolling NO electrical steel strip, strip breaks can occur more frequently. The permissible level of brittleness depends on the thickness of the electrical steel strip or sheet, so that an optimization of the material properties is necessary, taking into account opposing physical effects. In view of the above, the invention is based on the task of providing alternatives to the known electrical strips or sheets which meet the requirements in terms of their magnetic properties on the one hand and their mechanical properties on the other to the same or greater extent and at the same time enable them to be produced in small thicknesses. The developers' main aim is to ensure good handling, particularly with a view to avoiding as far as possible any impairment of cold rollability. The invention is solved with a non-grain-oriented metallic electrical strip or sheet having the features of claim 1 and with a method for producing a non-grain-oriented electrical strip having the features of claim 10. The invention is also solved with an electrical strip having the features of claim 20 and with a use according to claim 21. A non-grain-oriented metallic electrical strip or sheet is provided. The non-grain-oriented metallic electrical strip or sheet consists of a composition with the following components, each in percent by weight, in short: % by weight: C: 0.0005 up to 0.0040, preferably 0.0005 up to 0.0035; Si: 2.8 up to 3.2, p