# US 2020/0399749 A1 · Method for dip-coating a metal strip > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0399749 A1 - Document ID: US20200399749A1 - Status: Published application - Kind: A1 - Application number: 16/979,232 - Filed: 2019-02-14 - Published: 2020-12-24 - Earliest claimed: 2018-03-12 - Assignees: ArcelorMittal - Applicants: Arcelormittal - Inventors: Angel GARCIA MARTINO; Inocencio GARCIA-CHAPA - Web page: https://patentgrep.com/patent/US20200399749A1 ## CPC - C21D 9/561: {with a controlled atmosphere or vacuum} - C21D 9/562: {Details} - C23C 2/0034: {Details related to elements immersed in bath} - C23C 2/00344: {Means for moving substrates, e.g. immersed rollers or immersed bearings} - C23C 2/0038: {characterised by the pre-treatment chambers located immediately upstream of the bath or occurring locally before the dipping process} - C23C 2/004: {Snouts} - C23C 2/02: Pretreatment of the material to be coated, e.g. for coating on selected surface areas (C23C2/30 takes precedence) - C23C 2/022: {by heating} - C23C 2/0222: {in a reactive atmosphere, e.g. oxidising or reducing atmosphere (C23C2/024 takes precedence)} - C23C 2/0224: {Two or more thermal pretreatments} - C23C 2/06: Zinc or cadmium or alloys based thereon - C23C 2/40: Plates; Strips - C23C 2/50: {Controlling or regulating the coating processes (C23C2/14 takes precedence)} - C23F 17/00: Multi-step processes for surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by subclass C21D or C22F or class C25 (coating for obtaining at least two superposed coatings either by methods not provided for in a single one of main groups C23C2/00 - C23C26/00, or by combinations of methods providedfor in subclasses C23C and C25D, C23C28/00) - 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) - 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) - C23F: NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE (working metal by laser beams B23K26/00; desurfacing by applying flames B23K7/00; working of metal by electro-erosion B23H; producing decorative effects by removing surface material, e.g. by engraving, by etching, B44C1/22; electrolytic etching or polishing C25F); INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25 ## Abstract Equipment for the continuous hot dip-coating of a metal strip 9 including an annealing furnace, a tank 2 containing a liquid metal bath 3, a snout connecting the annealing furnace and tank 2, through which the metal strip 9 runs in a protective atmosphere and the lower part of the snout, the sabot 5, is at least partly immersed in the liquid metal bath 3 in order to define with the surface of the bath, and inside this snout, a liquid seal 6, an overflow 7 not connected to the snout, the overflow 7 including at least one tray 8, placed in the vicinity of the strip 9 when entering the liquid metal bath 3 and encompassed by liquid seal 6. ## Claims ### Claim at position 1 1-15. (canceled) ### Claim at position 2 16: Equipment for continuous hot dip-coating of a metal strip, the equipment comprising: an annealing furnace; a tank containing a liquid metal bath; a snout connecting the annealing furnace and the tank, the metal strip running through the snout in a protective atmosphere, a lower part of the snout being at least partly immersed in the liquid metal bath in order to define with a surface of the bath, and an inside of the snout, a liquid seal; an overflow not connected to the snout, the overflow including at least one tray placed in the vicinity of the strip when entering the liquid metal bath and encompassed by the liquid seal. ### Claim at position 3 (depends on 16) 17: The equipment as recited in claim 16 wherein the snout is liftable and lowerable. ### Claim at position 4 (depends on 16) 18: The equipment as recited in claim 16 wherein the tray is formed by: an internal wall facing one side of the strip, directed toward the surface of the liquid seal, an internal wall upper edge being positioned below the surface of the bath; an external wall facing the snout, directed toward the surface of the liquid seal, an external wall upper edge being positioned above the surface of the bath; a connector part between the external and internal wall lower edges and also a side wall at each shared extremity of the internal and external walls connecting all edges; the internal wall edge upper edge being lower than the external wall upper edge. ### Claim at position 5 (depends on 18) 19: The equipment as recited in claim 18 wherein the overflow includes means for maintaining a level of liquid metal at a level below the surface of the liquid seal in order to set up a natural flow of the liquid metal in the tray, the natural flow of the liquid metal being greater than 50 mm in order to prevent metal oxide particles and intermetallic compound particles from rising as a countercurrent to the flow of liquid metal. ### Claim at position 6 (depends on 18) 20: The equipment as recited in claim 18 wherein the internal wall upper edge includes, in a longitudinal direction, a succession of hollows and projections. ### Claim at position 7 (depends on 18) 21: The equipment as recited in claim 18 wherein the overflow is removable when the snout is lifted. ### Claim at position 8 (depends on 19) 22: The equipment as recited in claim 19 wherein the tray and the means for maintaining the level are fixed to the edges of the tank by supports. ### Claim at position 9 (depends on 22) 23: The equipment as recited in claim 22 wherein the tray is connected to the means for maintaining the level and the support by connectors, the connectors of the overflow being curved towards a bottom of the coating bath so that a lowest part of the connectors is beneath the liquid seal allowing the lower part of the snout to be under the liquid seal and above the lowest part of the support. ### Claim at position 10 (depends on 22) 24: The equipment as recited in claim 22 wherein the supports are movable along the edges of the bath allowing the overflow to shift along the edges of said bath. ### Claim at position 11 (depends on 22) 25: The equipment as recited in claim 22 wherein the supports are shiftable along a perpendicular to the bath surface. ### Claim at position 12 (depends on 16) 26: The equipment as recited in claim 16 wherein the overflow has two trays positioned symmetrically to an entry of the metal strip in the liquid metal. ### Claim at position 13 (depends on 16) 27: The equipment as recited in claim 16 wherein the overflow is composed of one tray continuously surrounding the metal strip formed by an internal wall facing one side of the strip, directed toward the surface of the liquid seal, an internal wall upper edge being positioned below the surface of the bath, an external wall facing the snout directed toward the surface of the liquid seal, an external wall upper edge being positioned above the surface of the bath, a horizontal wall between the external and internal wall lower edges. ### Claim at position 14 (depends on 16) 28: The equipment as recited in claim 16 wherein the snout includes the lower part is removable. ### Claim at position 15 (depends on 16) 29: A method for depositing a metallic coating by hot-dip coating in the equipment as recited in claim 16, the method comprising: recrystallization annealing of the steel strip in an annealing furnace; passing the steel strip from the annealing furnace to the liquid metal bath in the snout; and hot dip-coating of the annealed steel strip in the liquid metal bath. ### Claim at position 16 (depends on 16) 30: A method for replacing a worn lower part of a snout from a hot dip-coating process in the equipment as recited in claim 16, the method comprising: lifting the snout to setting the lower part above the liquid bath, the lower part being revocable; and lifting the overflow and removing the lower part of the snout and replacing the lower part by a new lower part.