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KR-20260064985-A - Non-oriented electrical steel sheet, motor containing the same, and method for manufacturing non-oriented electrical steel sheet

KR20260064985AKR 20260064985 AKR20260064985 AKR 20260064985AKR-20260064985-A

Abstract

The present invention provides a non-oriented electrical steel sheet comprising, in weight % (wt%), silicon (Si): 0.1 to 1.6%, aluminum (Al): 0 (greater than) to 0.5%, manganese (Mn): 0.2 to 0.4%, carbon (C): 0 (greater than) to 0.08%, sulfur (S): 0 (greater than) to 0.0050%, nitrogen (N): 0 (greater than) to 0.0030%, titanium (Ti): 0 (greater than) to 0.0050%, phosphorus (P): 0 (greater than) to 0.1%, and the remainder being iron (Fe) and other unavoidable impurities, wherein the volume fraction of the texture satisfies Formula 1 below. [Equation 1] (Here, f{100}//ND, f{110}//ND, f{111}//ND represent the volume fractions of {100}, {110}, {111} textures relative to the sum of all orientations.)

Inventors

  • 김민성
  • 채원기
  • 고재현
  • 최혜정

Assignees

  • 현대제철 주식회사

Dates

Publication Date
20260508
Application Date
20241030

Claims (19)

  1. In weight % (wt%), silicon (Si): 0.1 to 1.6%, aluminum (Al): 0 to 0.5%, manganese (Mn): 0.2 to 0.4%, carbon (C): 0 to 0.08%, sulfur (S): 0 to 0.0050%, nitrogen (N): 0 to 0.0030%, titanium (Ti): 0 to 0.0050%, phosphorus (P) 0 to 0.1%, and the remainder being iron (Fe) and other unavoidable impurities, Non-oriented electrical steel sheet in which the volume fraction of the texture satisfies the following Equation 1. [Equation 1] (Here, f{100}//ND, f{110}//ND, f{111}//ND represent the volume fractions of {100}, {110}, {111} textures relative to the sum of all orientations.)
  2. In paragraph 1, A non-oriented electrical steel sheet having an f{100}//ND orientation fraction of 14% or more in the texture of the above non-oriented electrical steel sheet.
  3. In paragraph 1, A non-oriented electrical steel sheet having an f{110}//ND orientation fraction of 10% or more in the texture of the above non-oriented electrical steel sheet.
  4. In paragraph 1, Non-oriented electrical steel sheet in which the f{111}//ND orientation fraction in the above non-oriented electrical steel sheet texture is less than 25%
  5. In paragraph 1, A non-oriented electrical steel sheet having an average grain size of 30㎛ to 100㎛.
  6. In paragraph 1, A non-oriented electrical steel sheet having an iron loss (W 15/50 ) of 6.0 W/kg or less.
  7. In paragraph 1, A non-oriented electrical steel sheet having a magnetic flux density (B 50 ) of 1.75T or more.
  8. As a method for manufacturing non-oriented electrical steel sheets, A hot rolling step for manufacturing a hot-rolled plate by hot rolling a slab comprising, in weight % (wt%), silicon (Si): 0.1 to 1.6%, aluminum (Al): 0 (greater) to 0.5%, manganese (Mn): 0.2 to 0.4%, carbon (C): 0 (greater) to 0.08%, sulfur (S): 0 (greater) to 0.0050%, nitrogen (N): 0 (greater) to 0.0030%, titanium (Ti): 0 (greater) to 0.0050%, phosphorus (P): 0 (greater) to 0.1%, and the remainder being iron (Fe) and other unavoidable impurities; A cold rolling step for manufacturing a cold rolled plate by cold rolling the above hot rolled plate; and A cold rolling annealing step of manufacturing a cold rolling annealed plate by annealing the above cold rolling plate; Includes, A method for manufacturing a non-oriented electrical steel sheet, wherein the speed ratio of the upper roll and the lower roll in the above cold rolling step is 1.5 or more and less than 3.0.
  9. In paragraph 8, A method for manufacturing a non-oriented electrical steel sheet, wherein the coefficient of friction between the upper roll and the lower roll in the above cold rolling step is 0.2 or higher.
  10. In paragraph 8, A method for manufacturing a non-oriented electrical steel sheet, wherein the reduction rate per pass in the above cold rolling step is 25% or more and 50% or less.
  11. In paragraph 8, A method for manufacturing a non-oriented electrical steel sheet, wherein the iron loss (W 15/50 ) of the above non-oriented electrical steel sheet is 6.0 W/kg or less.
  12. In paragraph 8, A method for manufacturing a non-oriented electrical steel sheet, wherein the magnetic flux density (B 50 ) of the above non-oriented electrical steel sheet is 1.75T or higher.
  13. In paragraph 8, A method for manufacturing a non-oriented electrical steel sheet, wherein the volume fraction of the texture within the non-oriented electrical steel sheet satisfies the following Equation 1. [Equation 1] (Here, f{100}//ND, f{110}//ND, f{111}//ND represent the volume fractions of {100}, {110}, {111} textures relative to the sum of all orientations.)
  14. A motor comprising a motor core, wherein the motor core is, It comprises a non-oriented electrical steel sheet comprising, in weight % (wt%), silicon (Si): 0.1 to 1.6%, aluminum (Al): 0 to 0.5%, manganese (Mn): 0.2 to 0.4%, carbon (C): 0 to 0.08%, sulfur (S): 0 to 0.0050%, nitrogen (N): 0 to 0.0030%, titanium (Ti): 0 to 0.0050%, phosphorus (P) 0 to 0.1%, and the remainder being iron (Fe) and unavoidable impurities, and A motor in which the volume fraction of the texture within the above-mentioned non-oriented electrical steel sheet satisfies the following Equation 1. [Equation 1] (Here, f{100}//ND, f{110}//ND, f{111}//ND represent the volume fractions of {100}, {110}, {111} textures relative to the sum of all orientations.)
  15. In Paragraph 14, A motor in which the f{100}//ND orientation fraction in the texture of the above non-oriented electrical steel sheet is 14% or more.
  16. In Paragraph 14, A motor in which the f{110}//ND orientation fraction in the texture of the above non-oriented electrical steel sheet is 10% or more.
  17. In Paragraph 14, Motor, in which the f{111}//ND orientation fraction in the above non-oriented electrical steel sheet structure is less than 25%.
  18. In Paragraph 14, A motor having an average grain size of 30㎛ to 100㎛ of the above-mentioned non-oriented electrical steel sheet.
  19. In Paragraph 14, A motor in which the iron loss (W 15/50 ) of the above non-oriented electrical steel sheet is 6.0 W/kg or less.

Description

Non-oriented electrical steel sheet, motor containing the same, and method for manufacturing non-oriented electrical steel sheet The present invention relates to a non-oriented electrical steel sheet and a method for manufacturing the same. Due to policies to reduce carbon dioxide ( CO2 ) emissions to prevent global warming, existing internal combustion engine vehicles are being rapidly replaced by eco-friendly vehicles (hybrid vehicles (HEV), electric vehicles (EV), etc.), especially electric vehicles (EV). Since electric vehicles (EVs) must generate high torque at low speeds or during acceleration, and rotate at high speeds (e.g., 200 Hz or higher) during constant speed and high-speed driving, the non-oriented electrical steel sheets used as the core material for the motor must simultaneously satisfy high magnetic flux density and low iron loss. Factors affecting the magnetic properties of these non-oriented electrical steel sheets include chemical composition, sheet thickness, microstructure, insulating coating layer, and texture. Furthermore, these various factors are influenced by the manufacturing process conditions of the non-oriented electrical steel sheets. Non-oriented electrical steel sheets are manufactured through the processes of steelmaking/continuous casting, hot rolling, heat treatment after hot rolling, cold rolling, heat treatment after cold rolling, and coating, and non-oriented electrical steel sheets with excellent magnetic properties can be manufactured by optimizing the conditions of each process. To reduce iron loss in non-oriented electrical steel sheets, methods such as 1) reducing sheet thickness, 2) increasing resistivity, and 3) improving texture can be used. Among these, improving texture is one of the important factors for improving iron loss and magnetic flux density. For example, the texture of non-oriented electrical steel sheets has a significant impact on magnetic properties. FIG. 1 is a flowchart schematically illustrating a method for manufacturing a non-oriented electrical steel sheet according to one embodiment of the present invention. The present invention will be described in detail below. However, in describing the present invention, if it is determined that a detailed description of related known technologies or configurations may unnecessarily obscure the essence of the present invention, such detailed description will be omitted. In the following embodiments, terms such as first, second, etc. are used not in a limiting sense, but for the purpose of distinguishing one component from another component. In the following examples, singular expressions include plural expressions unless the context clearly indicates otherwise. In the following embodiments, when various components such as layers, films, regions, and plates are described as being "on" another component, this includes not only cases where they are "directly on" another component, but also cases where another component is interposed between them. In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and therefore the present invention is not necessarily limited to what is illustrated. In the following embodiments, terms such as "include" or "have" mean that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components may be added. In this specification, "A and/or B" indicates the case where it is A, B, or both A and B. Additionally, in this specification, "at least one of A and B" indicates the case where it is A, B, or both A and B. Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as generally understood by those skilled in the art to which this invention pertains. Terms defined in commonly used dictionaries are further interpreted to have meanings consistent with relevant technical literature and the present disclosure, and are not interpreted in an ideal or highly formal sense unless otherwise defined. Hereinafter, embodiments of the present invention are described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. FIG. 1 is a flowchart schematically illustrating a method for manufacturing a non-oriented electrical steel sheet according to one embodiment of the present invention. Referring to FIG. 1, a method for manufacturing a non-oriented electrical steel sheet according to one embodiment of the present invention may include a hot rolling step (S100), a pre-annealing step (S200), a cold rolling step (S300), a cold rolling annealing step (S400), and a coating step (S500). In a method for manufacturing a non-orien