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KR-20260064984-A - Non-oriented electrical steel sheet and method for manufacturing the same

KR20260064984AKR 20260064984 AKR20260064984 AKR 20260064984AKR-20260064984-A

Abstract

One embodiment of the present invention comprises a hot rolling step of producing a hot rolled plate by hot rolling a slab containing, in weight percent, carbon (C): 0.005% or less, silicon (Si): 1.8% or more and 3.5% or less, manganese (Mn): 0.1% or more and 0.8% or less, aluminum (Al): greater than 0% and 0.03% or less, sulfur (S): greater than 0% and 0.02% or less, nitrogen (N): greater than 0% and 0.005% or less, titanium (Ti): greater than 0% and 0.005% or less, phosphorus (P): greater than 0% and 0.02% or less, and the remainder being iron and other impurities; a preliminary annealing step of producing a hot rolled annealed plate by pre-annealing the hot rolled plate; a cold rolling step of producing a cold rolled plate by cold rolling the hot rolled annealed plate; a final annealing step of producing a final annealed plate by final annealing the cold rolled plate; and a step of irradiating the final annealed plate with a laser beam. Silicon (Si), manganese (Mn), and sulfur (S) contained in the slab satisfy Formula 1 below, providing a method for manufacturing a non-oriented electrical steel sheet and a non-oriented electrical steel sheet manufactured thereby. <Equation 1> (Here, [Si], [S], and [Mn] respectively represent the weight percent of silicon (Si), manganese (Mn), and sulfur (S) contained in the non-oriented electrical steel sheet.)

Inventors

  • 최수영
  • 유성현
  • 안용근
  • 정종민
  • 이한샘

Assignees

  • 현대제철 주식회사

Dates

Publication Date
20260508
Application Date
20241030

Claims (14)

  1. 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 percent, carbon (C): 0.005% or less, silicon (Si): 1.8% or more and 3.5% or less, manganese (Mn): 0.1% or more and 0.8% or less, aluminum (Al): greater than 0% and 0.03% or less, sulfur (S): greater than 0% and 0.02% or less, nitrogen (N): greater than 0% and 0.005% or less, titanium (Ti): greater than 0% and 0.005% or less, phosphorus (P): greater than 0% and 0.02% or less, and the remainder being iron and other impurities; A preliminary annealing step for manufacturing a hot-rolled annealed plate by pre-anesthetizing the above hot-rolled plate; A cold rolling step for manufacturing a cold-rolled plate by cold-rolling the above hot-rolled annealed plate; A final annealing step for manufacturing a final annealed plate by finally annealing the above cold-rolled plate; and The method includes the step of irradiating the final annealed plate with a laser beam; A method for manufacturing a non-oriented electrical steel sheet in which the silicon (Si), manganese (Mn), and sulfur (S) contained in the above slab satisfy the following formula 1. <Equation 1> (Here, [Si], [S], and [Mn] respectively represent the weight percent of silicon (Si), manganese (Mn), and sulfur (S) contained in the non-oriented electrical steel sheet.)
  2. In paragraph 1, In the above laser beam irradiation step, A method for manufacturing a non-oriented electrical steel sheet, wherein the power of the laser beam (P), the depth of the laser irradiation line (Dp), the width of the laser irradiation line (Wd), and the laser beam irradiation interval (Itv) satisfy the following Equation 2. <Equation 2> (Here, P represents the laser beam power (W), Dp represents the laser irradiation depth (μm), Wd represents the laser irradiation width (μm), and Itv represents the laser beam irradiation interval (mm).)
  3. In paragraph 1, In the above laser beam irradiation step, A method for manufacturing non-oriented electrical steel sheets, wherein the power of the laser beam is 1 W to 30 W.
  4. In paragraph 1, In the above laser beam irradiation step, A method for manufacturing a non-oriented electrical steel sheet, wherein, in one embodiment, the irradiation angle of the laser beam is 60˚ to 90˚ from the rolling direction.
  5. In paragraph 1, In the above laser beam irradiation step, A method for manufacturing a non-oriented electrical steel sheet, wherein the depth of the laser irradiation beam is 3 μm to 15 μm.
  6. In paragraph 1, In the above laser beam irradiation step, A method for manufacturing a non-oriented electrical steel sheet, wherein the width of the laser irradiation line is 50 μm to 90 μm.
  7. In paragraph 1, In the above laser beam irradiation step, A method for manufacturing a non-oriented electrical steel sheet, wherein the laser beam irradiation interval is 1 nm to 7 nm.
  8. In paragraph 1, In the above laser beam irradiation step, A method for manufacturing non-oriented electrical steel sheets, wherein the scanning speed of the laser beam is 100 mm/s to 120 mm/s.
  9. In paragraph 1, A method for manufacturing a non-oriented electrical steel sheet, wherein the average {001} magnetic domain width contained in the final annealed sheet irradiated with the above laser beam is 150 μm to 300 μm.
  10. In paragraph 1, After the final annealing step and before the laser beam irradiation step, A method for manufacturing a non-oriented electrical steel sheet, further comprising the step of forming a coating layer on the final annealed sheet.
  11. As a non-oriented electrical steel sheet, In weight percent, carbon (C): 0.005% or less, silicon (Si): 1.8% or more and 3.5% or less, manganese (Mn): 0.1% or more and 0.8% or less, aluminum (Al): greater than 0% and 0.03% or less, sulfur (S): greater than 0% and 0.02% or less, nitrogen (N): greater than 0% and 0.005% or less, titanium (Ti): greater than 0% and 0.005% or less, phosphorus (P): greater than 0% and 0.02% or less, and the remainder being iron and other impurities, The silicon (Si), manganese (Mn), and sulfur (S) contained in the above non-oriented electrical steel sheet satisfy the following formula 1, the non-oriented electrical steel sheet. <Equation 1> (Here, [Si], [S], and [Mn] respectively represent the weight percent of silicon (Si), manganese (Mn), and sulfur (S) contained in the non-oriented electrical steel sheet.)
  12. In Paragraph 11, A non-oriented electrical steel sheet having an average grain size of 35 μm to 500 μm.
  13. In Paragraph 11, A non-oriented electrical steel sheet having an average {001} magnetic domain width of 150 μm to 300 μm.
  14. In Paragraph 11, The above non-oriented electrical steel sheet is a non-oriented electrical steel sheet having an iron loss of 12.1 W/kg or less (based on W 10/400 ).

Description

Non-oriented electrical steel sheet and method for manufacturing the same Embodiments of the present invention relate to non-oriented electrical steel sheets and a method for manufacturing the same. Recently, there has been an increasing demand for environmental conservation and improved energy efficiency. In particular, the transition from internal combustion engine vehicles to electric or hybrid vehicles is accelerating. Non-oriented electrical steel is primarily used as a material for transformers and rotating machinery such as motors. To improve the efficiency of motors used to drive electric vehicles, it is required to enhance the magnetic properties of non-oriented electrical steel. The characteristics required for non-oriented electrical steel are high magnetic flux density and low iron loss. Iron loss refers to energy loss caused by the iron core material; to reduce iron loss in non-oriented electrical steel, the sheet thickness must be reduced, resistivity increased, or the texture improved to facilitate magnetization. However, reducing the plate thickness may lower productivity during the process, and increasing the content of alloying elements with high resistivity, such as silicon (Si), to increase resistivity may reduce rolling performance and lower productivity. Additionally, if the silicon (Si) content is excessive, fracture of the steel plate may occur during cold rolling, and magnetic flux density may decrease. Aluminum (Al) or manganese (Mn) may be added instead of silicon (Si). However, if the aluminum (Al) content is excessive, AlN precipitates may form, increasing iron loss, and grain growth may be inhibited, which may degrade magnetic properties. Related technologies include Korean Registered Patent Publication No. 10-1633249 (Title of Invention: Non-oriented electrical steel sheet and method of manufacturing the same), etc. FIG. 1 is a flowchart schematically illustrating a method for manufacturing a non-oriented electrical steel sheet according to one embodiment. The present invention is capable of various modifications and may have various embodiments; specific embodiments are illustrated in the drawings and described in detail in the detailed description. The effects and features of the present invention, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various forms. In this specification, terms such as first, second, etc. are used not in a limiting sense, but for the purpose of distinguishing one component from another. In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprising" or "having" 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. And, "at least one of A and B" indicates the case where it is A, B, or both A and B. In this specification, 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 other components are interposed between them. In this specification, when it is stated that a membrane, region, component, etc. is connected, it includes cases where the membrane, region, or component is directly connected, or/or cases where other membranes, regions, or components are interposed between them to form an indirect connection. For example, when it is stated that a membrane, region, or component, etc. is electrically connected in this specification, it indicates cases where the membrane, region, or component, etc. are directly electrically connected, and/or cases where other membranes, regions, or components are interposed between them to form an indirect electrical connection. In this specification, the x-axis, y-axis, and z-axis are not limited to three axes in an orthogonal coordinate system and may be interpreted in a broader sense that includes them. For example, the x-axis, y-axis, and z-axis may be orthogonal to each other, but they may also refer to different directions that are not orthogonal to each other. Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. When describing with reference to the drawings, identical or corresponding components are given the same reference numerals, and redundant descriptions thereof will be omitted. For convenience of explanation, the size of components in the drawings may be exaggerated or reduced. For example, the size and thickness of each component shown in the drawings are depicted arbitrarily