# US 12,217,889 B2 · Grain-oriented electrical steel sheet, and steel sheet serving as base sheet for grain-oriented electrical steel sheet > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,217,889 B2 - Document ID: US12217889B2 - Status: Granted - Kind: B2 - Application number: 17/422,011 - Filed: 2020-01-16 - Published: 2022-03-31 - Granted: 2025-02-04 - Earliest claimed: 2019-01-16 - Assignees: Nippon Steel Corporation - Applicants: Nippon Steel Corporation - Inventors: Shuichi Nakamura; Yoshiyuki Ushigami; Hiroyasu Fujii - Web page: https://patentgrep.com/patent/US12217889B2 ## CPC - C21D 8/1277: involving a particular surface treatment (C21D8/1294 takes precedence) - H01F 1/147: Alloys characterised by their composition {(treatment thereof for enhancing their electromagnetic properties C21D8/12)} - C21D 6/008: {containing Si} - C21D 8/1233: {Cold rolling} - C21D 8/1255: {with diffusion of elements, e.g. decarburising, nitriding} - C21D 8/1272: {Final recrystallisation annealing} - C21D 8/1288: {Application of a tension-inducing coating} - C21D 9/46: for sheet metals - C22C 38/02: containing silicon - C23C 22/20: containing aluminium cations - C23C 22/74: for obtaining burned-in conversion coatings - C23C 22/78: Pretreatment of the material to be coated - C23G 1/081: {solutions containing H2SO4} - H01F 1/18: with insulating coating - C21D 2201/05: Grain orientation - 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 (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass C23F17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B) - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - C22C: ALLOYS (treatment of alloys C21D, C22F) - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - C23G: CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS ## Abstract A grain-oriented electrical steel sheet according to an aspect of the present invention includes an underlying steel sheet and a tension-insulation coating arranged on the surface of the underlying steel sheet, and a ten-point average roughness RzL in an L direction obtained when the tension-insulation coating is removed from the grain-oriented electrical steel sheet with an alkaline solution, and then the surface of the underlying steel sheet is measured in a rolling direction is 6.0 μm or less. ## Claims ### Claim 1 A grain-oriented electrical steel sheet comprising an underlying steel sheet and a tension-insulation coating arranged on a surface of the underlying steel sheet, wherein the underlying steel sheet obtained by removing the tension-insulation coating from the grain-oriented electrical steel sheet with an alkaline solution has a ten-point average roughness RzL in a rolling direction of 6.0 μm or less and an arithmetic average roughness RaC in the direction perpendicular to the rolling direction is less than 0.6 μm. ### Claim 2 (depends on 1) The grain-oriented electrical steel sheet according to claim 1, wherein the underlying steel sheet obtained by removing the tension-insulation coating from the grain-oriented electrical steel sheet with an alkaline solution has a ten-point average roughness RzC in a direction perpendicular to the rolling direction of 8.0 μm or less. ### Claim 3 (depends on 2) The grain-oriented electrical steel sheet according to claim 2, wherein the ten-point average roughness RzL in the rolling direction and the ten-point average roughness RzC in the direction perpendicular to the rolling direction satisfy RzL/RzC<1.0. ### Claim 4 (depends on 1) The grain-oriented electrical steel sheet according to claim 1, wherein an arithmetic average roughness RaL in the rolling direction is less than 0.4 μm. ### Claim 5 (depends on 1) A steel sheet serving as a base sheet of the grain-oriented electrical steel sheet according to claim 1, wherein a ten-point average roughness RzL in the rolling direction is 6.0 μm or less and an arithmetic average roughness RaC in the direction perpendicular to the rolling direction is less than 0.6 μm. ### Claim 6 (depends on 5) The steel sheet according to claim 5, wherein a ten-point average roughness RzC in the direction perpendicular to the rolling direction is 8.0 μm or less. ### Claim 7 (depends on 6) The steel sheet according to claim 6, wherein the ten-point average roughness RzL in the rolling direction and the ten-point average roughness RzC in the direction perpendicular to the rolling direction satisfy RzL/RzC<1.0. ### Claim 8 (depends on 5) The steel sheet according to claim 5, wherein an arithmetic average roughness RaL in the rolling direction is less than 0.4 μm. ### Claim 9 (depends on 2) The grain-oriented electrical steel sheet according to claim 2, wherein an arithmetic average roughness RaL in the rolling direction is less than 0.4 μm. ### Claim 10 (depends on 2) The grain-oriented electrical steel sheet according to claim 2, wherein an arithmetic average roughness RaC in the direction perpendicular to the rolling direction is less than 0.6 μm. ### Claim 11 (depends on 6) The steel sheet according to claim 6, wherein an arithmetic average roughness RaL in the rolling direction is less than 0.4 μm. ### Claim 12 (depends on 6) The steel sheet according to claim 6, wherein an arithmetic average roughness RaC in the direction perpendicular to the rolling direction is less than 0.6 μm. ### Claim 13 (depends on 1) The grain-oriented electrical steel sheet according to claim 1, wherein the tension-insulation coating is a non-magnetic substance. ### Claim 14 (depends on 2) The grain-oriented electrical steel sheet according to claim 2, wherein the ten-point average roughness RzL in the rolling direction and the ten-point average roughness RzC in the direction perpendicular to the rolling direction satisfy RzL/RzC<0.7. ### Claim 15 (depends on 1) The grain-oriented electrical steel sheet according to claim 1, wherein the underlying steel sheet obtained by removing the tension-insulation coating from the grain-oriented electrical steel sheet with an alkaline solution has a ten-point average roughness RzL in a rolling direction of 1.6 μm to 6.0 μm.