# US 11,441,219 B2 · Black plated steel sheet and manufacturing method therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,219 B2 - Document ID: US11441219B2 - Status: Granted - Kind: B2 - Application number: 16/448,017 - Filed: 2019-06-21 - Published: 2020-01-02 - Granted: 2022-09-13 - Earliest claimed: 2016-12-21 - Assignees: Research Institute of Industrial Science & Technology - Applicants: Research Institute of Industrial Science & Technology - Inventors: Hye Jeong Kim; Gab Sik Byun; Kyung Hwang Lee; Mi Seon Choi - Web page: https://patentgrep.com/patent/US11441219B2 ## CPC - C23C 8/12: using elemental oxygen or ozone - C22C 18/00: Alloys based on zinc - C22C 18/04: with aluminium as the next major constituent - C23C 2/06: Zinc or cadmium or alloys based thereon - C23C 2/261: {in a gas atmosphere, e.g. inert or reducing atmosphere} - C23C 2/28: Thermal after-treatment, e.g. treatment in oil bath - C23C 2/40: Plates; Strips - C23C 8/16: using oxygen-containing compounds, e.g. water, carbon dioxide - C23C 30/00: Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process (C23C26/00, C23C28/00 take precedence) - 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) - C22C: ALLOYS (treatment of alloys C21D, C22F) ## Abstract Embodiments of the present invention provide a technique for forming a film having a high added value appearance quality and excellent hardness on the surface of a steel sheet in a short time. ## Claims ### Claim 1 A method for producing black plated steel sheet comprising: an air removing step of removing some or all of the air inside a sealed container; an oxygen input step of injecting oxygen (O2) into the sealed container after the air removing step; and a humidifying heat treatment step of Zn plated steel sheet or Zn alloy-based plated steel sheet in the sealed container after the oxygen input step; wherein, in the humidifying heat treatment step, a brightness L value on the surface of the plated steel sheet is controlled to 60 or less (except 0), wherein, the air removing step is to remove all the air in the sealed container until the pressure inside the sealed container reaches 0 bar. ### Claim 2 (depends on 1) The method of claim 1, wherein, the oxygen input step is to inject oxygen into the sealed container through the air removing step until the pressure in the sealed container reaches 0.5 to 1.5 bar. ### Claim 3 (depends on 2) The method of claim 2, the humidifying heat treatment step is to be carried out in a temperature range of 100 to 160° C. ### Claim 4 (depends on 2) The method of claim 2, the humidifying heat treatment step is to be performed at a constant humidity, in the range of 50 to 100 RH %. ### Claim 5 (depends on 2) The method of claim 2, the humidifying heat treatment step is to be carried out in an oxygen concentration of 14 to 50% by volume. ### Claim 6 (depends on 5) The method of claim 5, the humidifying heat treatment step is to be carried out in an oxygen concentration of 14 to 35% by volume. ### Claim 7 (depends on 2) The method of claim 2, the humidifying heat treatment step is to be carried out within 2 hours (except 0 hours). ### Claim 8 (depends on 7) The method of claim 7, the humidifying heat treatment step is to be carried out for 0.5 to 2 hours. ### Claim 9 (depends on 1) The method of claim 1, the Zn alloy-based plated steel sheet is a ternary-based plated steel sheet of Al, Mg, and Zn. ### Claim 10 (depends on 9) The method of claim 9, the surface the Zn alloy-based plated steel sheet includes a plating layer comprising Al 1.0 to 22.0 wt %, Mg 1.3 to 10.0 wt %, the balance containing Zn and other unavoidable impurities. ### Claim 11 (depends on 10) The method of claim 10, wherein, in the humidifying heat treatment step, the plating layer is oxidized. ### Claim 12 (depends on 11) The method of claim 11, wherein, in the humidifying heat treatment step, the plating layer is oxidized, and then converted to a film comprising Zn matrix; and ZnO, Al2O3, and MgO mixed in the Zn matrix.