EP3701055A1 - A method for the manufacture of a coated steel sheet, two spot welded metal sheets and use thereof - Google Patents

A method for the manufacture of a coated steel sheet, two spot welded metal sheets and use thereof

Info

Publication number
EP3701055A1
EP3701055A1 EP18793483.1A EP18793483A EP3701055A1 EP 3701055 A1 EP3701055 A1 EP 3701055A1 EP 18793483 A EP18793483 A EP 18793483A EP 3701055 A1 EP3701055 A1 EP 3701055A1
Authority
EP
European Patent Office
Prior art keywords
steel sheet
coating
anyone
zinc
nickel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP18793483.1A
Other languages
German (de)
French (fr)
Inventor
Pascal BERTHO
Anirban Chakraborty
Hassan GHASSEMI-ARMAKI
Christian Allely
Tiago MACHADO AMORIM
Daniel Chaleix
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ArcelorMittal SA
Original Assignee
ArcelorMittal SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from PCT/IB2017/001281 external-priority patent/WO2018115946A1/en
Application filed by ArcelorMittal SA filed Critical ArcelorMittal SA
Publication of EP3701055A1 publication Critical patent/EP3701055A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/10—Electroplating with more than one layer of the same or of different metals
    • C25D5/12—Electroplating with more than one layer of the same or of different metals at least one layer being of nickel or chromium
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • 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
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/06—Zinc or cadmium or alloys based thereon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K11/00—Resistance welding; Severing by resistance heating
    • B23K11/10—Spot welding; Stitch welding
    • B23K11/11—Spot welding
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • 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
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
    • C23C2/022—Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • 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
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
    • C23C2/022—Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating
    • C23C2/0222—Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating in a reactive atmosphere, e.g. oxidising or reducing atmosphere
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • 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
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
    • C23C2/022—Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating
    • C23C2/0224—Two or more thermal pretreatments
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • 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
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
    • C23C2/026—Deposition of sublayers, e.g. adhesion layers or pre-applied alloying elements or corrosion protection
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • 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
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/34—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the shape of the material to be treated
    • C23C2/36—Elongated material
    • C23C2/40—Plates; Strips
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • 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
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/02—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material
    • C23C28/023—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material only coatings of metal elements only
    • C23C28/025—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material only coatings of metal elements only with at least one zinc-based layer
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/34—Pretreatment of metallic surfaces to be electroplated
    • C25D5/36—Pretreatment of metallic surfaces to be electroplated of iron or steel
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/48—After-treatment of electroplated surfaces
    • C25D5/50—After-treatment of electroplated surfaces by heat-treatment
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/001—Austenite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/002—Bainite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/008—Martensite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/001—Heat treatment of ferrous alloys containing Ni
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/005—Heat treatment of ferrous alloys containing Mn
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/008—Heat treatment of ferrous alloys containing Si
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D7/00—Electroplating characterised by the article coated
    • C25D7/06—Wires; Strips; Foils
    • C25D7/0614—Strips or foils

Definitions

  • the present invention relates to a method for the manufacture of a coated steel sheet.
  • the invention is particularly well suited for the manufacture of automotive vehicles.
  • Zinc based coatings are generally used because they allows for a protection against corrosion, thanks to barrier protection and cathodic protection.
  • the barrier effect is obtained by the application of a metallic coating on steel surface.
  • the metallic coating prevents the contact between steel and corrosive atmosphere.
  • the barrier effect is independent from the nature of coating and substrate.
  • sacrificial cathodic protection is based on the fact that zinc is a metal less noble that steel. Thus, if corrosion occurs, zinc is consumed preferentially to steel. Cathodic protection is essential in areas where steel is directly exposed to corrosive atmosphere, like cut edges where the surrounding zinc will be consumed before steel.
  • US2012100391 discloses a method for manufacturing a hot-dip galvanized steel sheet having good plating qualities, plating adhesion and spot weldability, the method comprising:
  • CM coating amount
  • the alloy phase is a Fe- Zn alloy phase accounting for 1 -20% of the cross-sectional area of the galvanized layer.
  • the object of the invention is to provide a steel sheet coated with a metallic coating which does not have LME issues. It aims to make available, in particular, an easy to implement method in order to obtain a part which does not have LME issues after the forming and/or the welding.
  • Another object is achieved by providing a steel sheet according to claim 17.
  • the steel sheet can also comprise any characteristics of claims 16 to 22.
  • spot welded joint can also comprise characteristics of claims 23 to 26.
  • steel or “steel sheet” means a steel sheet, a coil, a plate having a composition allowing the part to achieve a tensile strength up to 2500 MPa and more preferably up to 2000MPa.
  • the tensile strength is above or equal to 500 MPa, preferably above or equal to 980 MPa, advantageously above or equal to 1 180 MPa and even above or equal 1470 MPa.
  • the invention relates to method for the manufacture of a coated steel sheet comprising the following successive steps:
  • step B the coating of the steel sheet obtained in step A) with a first coating comprising nickel, such first coating not comprising iron, having a thickness equal or above 0.5 ⁇ and
  • the steel sheet is annealed in a continuous annealing.
  • the continuous annealing comprises a heating, a soaking and a cooling step. It can further comprise a pre-heating step.
  • the thermal treatment is performed in an atmosphere comprising from 1 to 30% of H 2 at a dew point between -10 and -60°C.
  • the atmosphere comprises from 1 to 10% of H 2 at a dew point between -10°C and -60°C.
  • the first coating comprising nickel is deposited by any deposition method known by the man skilled in the art. It can be deposited by vacuum deposition or electro-plating method. Preferably, it is deposited by electro-plating method.
  • the first coating comprises above 80%, more preferably above 90% by weight of nickel.
  • the first coating does not comprise phosphorus, nickel hydroxide or sulfur compounds such as sulfate salt.
  • the first coating consists of nickel.
  • the amount of nickel is >99% by weight and preferably is of 100%.
  • the first coating has a thickness equal or above ⁇ . ⁇ and advantageously equal or above 1 .6 ⁇ . More preferably, the first coating has a thickness between 1 .8 to 7.0 ⁇ .
  • the second layer comprises above 50%, more preferably above 75% of zinc and advantageously above 90% of zinc.
  • the second layer does not comprise nickel.
  • the second layer can be deposited by any deposition method known by the man skilled in the art. It can be by hot-dip coating, by vacuum deposition or by electro-galvanizing.
  • the coating based on zinc comprises 0.01 -8.0% Al, optionally 0.2-8.0% Mg, the remainder being Zn.
  • the coating based on zinc is deposited by hot-dip galvanizing.
  • the molten bath can also comprise unavoidable impurities and residuals elements from feeding ingots or from the passage of the steel sheet in the molten bath.
  • the optionally impurities are chosen from Sr, Sb, Pb, Ti, Ca, Mn, Sn, La, Ce, Cr, Zr or Bi, the content by weight of each additional element being inferior to 0.3% by weight.
  • the residual elements from feeding ingots or from the passage of the steel sheet in the molten bath can be iron with a content up to 5.0%, preferably 3.0%, by weight.
  • the second layer consists of zinc.
  • the percentage of Aluminum is comprised between 0.15 and 0.40% in the bath.
  • the steel sheet has a microstructure comprising from 1 to 50% of residual austenite, from 1 to 60% of martensite and optionally at least one element chosen from: bainite, ferrite, cementite and pearlite.
  • the martensite can be tempered or untempered.
  • the steel sheet has a microstructure comprising from 5 to 25 % of residual austenite.
  • the steel sheet has a microstructure comprising from 1 to 60% and more preferably between 10 to 60% of tempered martensite.
  • the steel sheet has a microstructure comprising from 10 to
  • bainite such bainite comprising from 10 to 20% of lower bainite, from 0 to 15% of upper bainite and from 0 to 5% of carbide free bainite.
  • the steel sheet has a microstructure comprising from 1 to 25% of ferrite.
  • the steel sheet has a microstructure comprising from 1 to 15% untempered martensite.
  • assembly After the manufacture of a steel sheet, in order to produce some parts of a vehicle, it is known to assembly by welding two metal sheets.
  • a spot welded joint is formed during the welding of at least two metal sheets, said spot being the link between the at least two metal sheets.
  • the welding is performed with an effective intensity is between 3kA and 15kA and the force applied on the electrodes is between 150 and 850 daN with said electrode active face diameter being between 4 and 10mm.
  • a spot welded joint of at least two metal sheets, comprising the coated steel sheet according to the present invention is obtained, such said joint containing less than 3 cracks having a size above ⁇ ⁇ and wherein the longest crack has a length below 300 ⁇ .
  • the second metal sheet is a steel sheet or an aluminum sheet. More preferably, the second metal sheet is a steel sheet according to the present invention.
  • the spot welded joint comprises a third metal sheet being a steel sheet or an aluminum sheet.
  • the third metal sheet is a steel sheet according to the present invention.
  • the steel sheet or the spot welded joint according to the present invention can be used for the manufacture of parts for automotive vehicle.
  • Trials 1 to 4 were prepared by performing an annealing in a continuous annealing in an atmosphere comprising 5% of H 2 and 95% of N 2 at a dew point of -60°C. The steel sheets were heated at a temperature of 900°C. Then, Trials 1 to 4 were coated with a different nickel coating thicknesses deposited by electro- galvanizing method. Finally, a zinc coating was deposited by electro-galvanizing method. Trial 5 was prepared by deposited a zinc coating by electro-galvanizing method after the continuous annealing of the steel sheet under similar atmosphere.
  • Trials according to the present invention show an excellent resistance to LME as compared to Trial 5. Indeed, the number of cracks of Trials according to the present invention is very low, even nonexistent, compared to Trial 5.
  • three coated steel sheets were also welded together by resistance spot welding. The number of cracks above ⁇ ⁇ was then evaluated using an optical microscope as well as SEM (Scanning Electron Microscopy) as shown in Table 3.
  • Trials according to the present invention show an excellent resistance to LME as compared to Trial 5.

Abstract

The present invention relates a method for the manufacture of a coated steel sheet.

Description

A METHOD FOR THE MANUFACTURE OF A COATED STEEL SHEET, TWO SPOT WELDED
METAL SHEETS AND USE THEREOF
The present invention relates to a method for the manufacture of a coated steel sheet. The invention is particularly well suited for the manufacture of automotive vehicles.
Zinc based coatings are generally used because they allows for a protection against corrosion, thanks to barrier protection and cathodic protection. The barrier effect is obtained by the application of a metallic coating on steel surface. Thus, the metallic coating prevents the contact between steel and corrosive atmosphere. The barrier effect is independent from the nature of coating and substrate. On the contrary, sacrificial cathodic protection is based on the fact that zinc is a metal less noble that steel. Thus, if corrosion occurs, zinc is consumed preferentially to steel. Cathodic protection is essential in areas where steel is directly exposed to corrosive atmosphere, like cut edges where the surrounding zinc will be consumed before steel.
However, when heating steps are performed on such zinc coated steel sheets, for example hot press hardening or welding, cracks are observed in steel which spread from the steel/coating interface. Indeed, occasionally, there is a reduction of metal mechanical properties due to the presence of cracks in coated steel sheet after the above operation. These cracks appear with the following conditions: high temperature; contact with a liquid metal having a low melting point (such as zinc) in addition to presence of tensile stress; heterogeneous diffusion of molten metal with substrate grain and grain boundaries. The designation for such phenomenon known as liquid metal embrittlement (LME), and also called liquid metal assisted cracking (LMAC).
US2012100391 discloses a method for manufacturing a hot-dip galvanized steel sheet having good plating qualities, plating adhesion and spot weldability, the method comprising:
- coating a base steel sheet with Ni in a coating amount (CM) of 0.1 -1 .0 g/m2;
- heating the Ni-coated steel sheet in a reducing atmosphere;
- cooling the heated steel sheet to the temperature (Xs) at which the steel sheet is fed into a galvanizing bath; and - feeding and immersing the cooled steel sheet in the galvanizing bath having an effective Al concentration (CAI) of 0.1 1 -0.14 wt % and a temperature (Tp) of 440- 460° C, wherein the temperature (Xs) at which the steel sheet is fed into the galvanizing bath satisfies the following relationship: CNi-(Xs_Tp)/2CAi=5-100.
It also discloses a hot-dip galvanized steel sheet wherein the alloy phase is a Fe- Zn alloy phase accounting for 1 -20% of the cross-sectional area of the galvanized layer.
However, in the above method, galvanizing was carried out in a bath comprising from 0.1 1 to0.14wt.% Al bath and thus inhibition layer was very week and Fe-Zn intermetallic phases formed. In industrial scale, this method is difficult to apply since the spot weldability depends on controlling parameters, including the amount of Ni coated, the Al concentration of the galvanizing bath, and the difference between the temperature of the galvanizing bath and the temperature at which the steel sheet is fed into the galvanizing bath. Moreover, the spot weldability performed is evaluated based on the electrode life, i.e. the number of continuous welding spots at the time when the nugget diameter reached 4Vt (t: steel sheet thickness) was measured. There is no mention of a reduction of the presence of cracks in coated steel sheet after the spot welding.
Thus, the object of the invention is to provide a steel sheet coated with a metallic coating which does not have LME issues. It aims to make available, in particular, an easy to implement method in order to obtain a part which does not have LME issues after the forming and/or the welding.
This object is achieved by providing a method according to claim 1 . The method can also comprise any characteristics of claims 2 to 15.
Another object is achieved by providing a steel sheet according to claim 17.
The steel sheet can also comprise any characteristics of claims 16 to 22.
Another object is achieved by providing a spot welded joint according to claim 24. The spot welded joint can also comprise characteristics of claims 23 to 26.
Finally, another object is achieved by providing the use of the steel sheet or the assembly according to claim 27. Other characteristics and advantages of the invention will become apparent from the following detailed description of the invention.
The designation "steel" or "steel sheet" means a steel sheet, a coil, a plate having a composition allowing the part to achieve a tensile strength up to 2500 MPa and more preferably up to 2000MPa. For example, the tensile strength is above or equal to 500 MPa, preferably above or equal to 980 MPa, advantageously above or equal to 1 180 MPa and even above or equal 1470 MPa.
The invention relates to method for the manufacture of a coated steel sheet comprising the following successive steps:
A. The provision of a annealed steel sheet having the following chemical composition in weight:
0.10 < C < 0.40%,
1 .5 < Mn < 3.0%,
0.7 < Si < 2.0%,
0.05 < Al < 1 .0%,
0.75 < (Si+AI) < 3.0 %,
and on a purely optional basis, one or more elements such as
Nb < 0.5 %,
B < 0.005%,
Cr≤ 1 .0%,
Mo < 0.50%,
Ni < 1 .0%,
Ti < 0.5%,
the remainder of the composition making up of iron and inevitable impurities resulting from the elaboration, such steel sheet being annealed at a temperature between 600 to 1200°C,
B the coating of the steel sheet obtained in step A) with a first coating comprising nickel, such first coating not comprising iron, having a thickness equal or above 0.5μιη and
C the coating of the steel sheet obtained in step B) with a second coating based on zinc. Without willing to be bound by any theory, it seems that Ni, being present at the interface between the steel having the above specific chemical composition and the overlying zinc coating, prevents liquid zinc penetration into steel during any heating steps being for example a welding. Thus, by applying the method according to the present invention, it is possible to obtain a barrier layer to LME.
Preferably, in step A), the steel sheet is annealed in a continuous annealing. For example, the continuous annealing comprises a heating, a soaking and a cooling step. It can further comprise a pre-heating step.
Advantageously, the thermal treatment is performed in an atmosphere comprising from 1 to 30% of H2 at a dew point between -10 and -60°C. For example, the atmosphere comprises from 1 to 10% of H2 at a dew point between -10°C and -60°C.
In step B), the first coating comprising nickel is deposited by any deposition method known by the man skilled in the art. It can be deposited by vacuum deposition or electro-plating method. Preferably, it is deposited by electro-plating method.
Preferably, in step B), the first coating comprises above 80%, more preferably above 90% by weight of nickel. Preferably, in step B), the first coating does not comprise phosphorus, nickel hydroxide or sulfur compounds such as sulfate salt.
In a preferred embodiment, the first coating consists of nickel. In this embodiment, the amount of nickel is >99% by weight and preferably is of 100%.
Preferably, in step A), the first coating has a thickness equal or above Ι .Ομιτι and advantageously equal or above 1 .6 μιη. More preferably, the first coating has a thickness between 1 .8 to 7.0μιη.
Advantageously, in step C), the second layer comprises above 50%, more preferably above 75% of zinc and advantageously above 90% of zinc. Preferably, the second layer does not comprise nickel. The second layer can be deposited by any deposition method known by the man skilled in the art. It can be by hot-dip coating, by vacuum deposition or by electro-galvanizing.
For example, the coating based on zinc comprises 0.01 -8.0% Al, optionally 0.2-8.0% Mg, the remainder being Zn. Preferably, the coating based on zinc is deposited by hot-dip galvanizing. In this embodiment, the molten bath can also comprise unavoidable impurities and residuals elements from feeding ingots or from the passage of the steel sheet in the molten bath. For example, the optionally impurities are chosen from Sr, Sb, Pb, Ti, Ca, Mn, Sn, La, Ce, Cr, Zr or Bi, the content by weight of each additional element being inferior to 0.3% by weight. The residual elements from feeding ingots or from the passage of the steel sheet in the molten bath can be iron with a content up to 5.0%, preferably 3.0%, by weight.
In a preferred embodiment, the second layer consists of zinc. When the coating is deposited by hot-dip galvanizing, the percentage of Aluminum is comprised between 0.15 and 0.40% in the bath.
With the method according to the present invention, a steel sheet coated with a first coating comprising nickel and having a thickness equal or above Ο.δμιη, such coating being directly topped by a zinc based layer, is obtained. It is believed that the first coating acts like a barrier layer to LME and prevent liquid metal to penetrate inside into the steel.
Preferably, the steel sheet has a microstructure comprising from 1 to 50% of residual austenite, from 1 to 60% of martensite and optionally at least one element chosen from: bainite, ferrite, cementite and pearlite. In this case, the martensite can be tempered or untempered.
In a preferred embodiment, the steel sheet has a microstructure comprising from 5 to 25 % of residual austenite.
Preferably, the steel sheet has a microstructure comprising from 1 to 60% and more preferably between 10 to 60% of tempered martensite.
Advantageously, the steel sheet has a microstructure comprising from 10 to
40% of bainite, such bainite comprising from 10 to 20% of lower bainite, from 0 to 15% of upper bainite and from 0 to 5% of carbide free bainite.
Preferably, the steel sheet has a microstructure comprising from 1 to 25% of ferrite.
Preferably, the steel sheet has a microstructure comprising from 1 to 15% untempered martensite. After the manufacture of a steel sheet, in order to produce some parts of a vehicle, it is known to assembly by welding two metal sheets. Thus, a spot welded joint is formed during the welding of at least two metal sheets, said spot being the link between the at least two metal sheets.
To produce a spot welded joint according to the invention, the welding is performed with an effective intensity is between 3kA and 15kA and the force applied on the electrodes is between 150 and 850 daN with said electrode active face diameter being between 4 and 10mm.
Thus, a spot welded joint of at least two metal sheets, comprising the coated steel sheet according to the present invention, is obtained, such said joint containing less than 3 cracks having a size above Ι ΟΟμιτι and wherein the longest crack has a length below 300 μιη. Preferably, the second metal sheet is a steel sheet or an aluminum sheet. More preferably, the second metal sheet is a steel sheet according to the present invention.
In another embodiment, the spot welded joint comprises a third metal sheet being a steel sheet or an aluminum sheet. For example, the third metal sheet is a steel sheet according to the present invention.
The steel sheet or the spot welded joint according to the present invention can be used for the manufacture of parts for automotive vehicle.
The invention will now be explained in trials carried out for information only.
They are not limiting.
Example
For all samples, steel sheets used have the following composition in weight percent: C=0.37wt.%, Mn=1 .9wt.%, Si=1 .9wt.%, Cr=0.35wt.%, Al=0.05wt.% and Mo=0.1 wt.%.
Trials 1 to 4 were prepared by performing an annealing in a continuous annealing in an atmosphere comprising 5% of H2 and 95% of N2 at a dew point of -60°C. The steel sheets were heated at a temperature of 900°C. Then, Trials 1 to 4 were coated with a different nickel coating thicknesses deposited by electro- galvanizing method. Finally, a zinc coating was deposited by electro-galvanizing method. Trial 5 was prepared by deposited a zinc coating by electro-galvanizing method after the continuous annealing of the steel sheet under similar atmosphere.
The resistance to LME of above Trial samples were evaluated by resistance spot welding method. To this end, for each Trial, two coated steel sheets were welded together by resistance spot welding. The type of the electrode was ISO Type B with a diameter of 16mm; the force of the electrode was of 5kN and the flow rate of water of was 1 .5g/min. The details welding cycle has been reported in Table 1
Table 1. Welding schedule
The number of cracks above Ι ΟΟμιη was then evaluated using an optical microscope as well as SEM (Scanning Electron Microscopy) as shown in Table 2.
Table 2. LME crack details after spot welding (2 layer stack-up condition)
*: according to the present invention.
Trials according to the present invention show an excellent resistance to LME as compared to Trial 5. Indeed, the number of cracks of Trials according to the present invention is very low, even nonexistent, compared to Trial 5. For each Trial, three coated steel sheets were also welded together by resistance spot welding. The number of cracks above Ι ΟΟμιη was then evaluated using an optical microscope as well as SEM (Scanning Electron Microscopy) as shown in Table 3.
Table 3. LME crack details after spot welding (3 layer stack-up condition)
*: according to the present invention.
Trials according to the present invention show an excellent resistance to LME as compared to Trial 5.

Claims

Claims
Method for the manufacture of a coated steel sheet comprising the following successive steps:
A. the provision of a annealed steel sheet having the following chemical composition in weight:
0.10 < C < 0.40%,
1 .5 < Mn < 3.0%,
0.7 < Si < 2.0%,
0.05 < Al < 1 .0%,
0.75 < (Si+AI) < 3.0 %,
and on a purely optional basis, one or more elements such as
Nb < 0.5 %,
B < 0.005%,
Cr≤ 1 .0%,
Mo < 0.50%,
Ni < 1 .0%,
Ti < 0.5%,
the remainder of the composition making up of iron and inevitable impurities resulting from the elaboration, such steel sheet being annealed at a temperature between 600 to 1200°C,
B. the coating of the steel sheet obtained in step A) with a first coating comprising nickel, such first coating not comprising iron, and having a thickness equal or above 0.5μιη and
C. the coating of the steel sheet obtained in step B) with a second coating based on zinc.
Method according to claim 1 , wherein in step A), the steel sheet is annealed in a continuous annealing.
Method according to claim 1 or 2, wherein in step A), the annealing is performed in an atmosphere comprising from 1 to 30% of H2 at a dew point between -10 and -60°C.
4. Method according to of claim 3, wherein in step B), the first coating comprises above 80% by weight of nickel.
5. Method according to claim 4, wherein in step B), the first coating comprises above 90% by weight of nickel.
6. Method according to claim 5, wherein in step B), the first coating consist of nickel. 7. Method according to anyone of claims 1 to 6, wherein in step B), the first coating does not comprise phosphorus, nickel hydroxide or sulfur compound .
8. Method according to claim 7, wherein in step B), the first coating has a thickness equal or above 1 .Ομιη.
9. Method according to claim 8, wherein in step B), the first coating has a thickness equal or above 1 .6 μιη.
10. Method according to claim 9, wherein in step B), the first coating has a thickness between 1 .8 to 7.0 μιη.
1 1 . Method according to anyone of claims 1 to 10, wherein in step C), the second layer comprises above 50% of zinc. 12. Method according to claim 1 1 , wherein in step C), the second layer comprises above 75% of zinc.
13. Method according to claim 12, wherein in step C), the second layer comprises above 90% of zinc.
14. Method according to claims 1 to 13, wherein in step C), the second layer does not comprise nickel.
15. Method according to claim 1 or 14, wherein in step C), the second layer consists of zinc.
16. A steel sheet obtainable from the method according to anyone of claims 1 to 15 coated with a first coating comprising nickel and having a thickness equal or above 0.5μιη, such first coating being directly topped by a zinc based layer. 17. Steel sheet according to claim 16, wherein the steel microstructure comprises from 1 to 50% of residual austenite, from 1 to 60% of martensite and optionally at least one element chosen from: bainite, ferrite, cementite and pearlite.
18. Steel sheet according to claim 17, wherein the microstructure comprises from 5 to 25 % of residual austenite.
19. Steel sheet according to claim 17 or 18, wherein the microstructure comprises from 1 to 60% of tempered martensite. 20. Steel sheet according to anyone of claims 17 to 19, wherein the microstructure comprises from 10 to 40% of bainite.
21 . Steel sheet according to anyone of claims 17 to 21 , wherein the microstructure comprises from 1 to 25% of ferrite.
22. Steel sheet according to anyone of claims 17 to 21 , wherein the microstructure comprises from 1 to 15% of untempered martensite.
23. Spot welded joint of at least two metal sheets comprising at least a steel sheet according to anyone of claims 16 to 28 or obtainable from the method according to anyone of claims 1 to 15, said joint containing less than 3 cracks having a size above Ι ΟΟμιτι and wherein the longest crack has a length below 300 μιη. 24. Spot welded joint according to claim 23, wherein the second metal sheet is a steel sheet or an aluminum sheet.
25. Spot welded joint according to claim 24, wherein the second metal sheet is a steel sheet according to anyone of claims 16 to 22 or obtainable from the method according to claims 1 to 15.
26. Spot welded joint according to anyone of claims 23 to claim 25 comprising a third metal sheet being a steel sheet or an aluminum sheet. 27. Use of a coated steel sheet according to claims 16 to 22 or a spot welded point according to anyone of claims 23 to 26, for the manufacture of part for automotive vehicle.
EP18793483.1A 2017-10-24 2018-10-19 A method for the manufacture of a coated steel sheet, two spot welded metal sheets and use thereof Withdrawn EP3701055A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
PCT/IB2017/001281 WO2018115946A1 (en) 2016-12-21 2017-10-24 A method for the manufacture of a coated steel sheet
PCT/IB2018/058157 WO2019082037A1 (en) 2017-10-24 2018-10-19 A method for the manufacture of a coated steel sheet, two spot welded metal sheets and use thereof

Publications (1)

Publication Number Publication Date
EP3701055A1 true EP3701055A1 (en) 2020-09-02

Family

ID=64017401

Family Applications (1)

Application Number Title Priority Date Filing Date
EP18793483.1A Withdrawn EP3701055A1 (en) 2017-10-24 2018-10-19 A method for the manufacture of a coated steel sheet, two spot welded metal sheets and use thereof

Country Status (9)

Country Link
US (1) US20200340124A1 (en)
EP (1) EP3701055A1 (en)
KR (1) KR102206933B1 (en)
CN (1) CN111279006A (en)
BR (1) BR112020006128A2 (en)
CA (1) CA3076994A1 (en)
MA (1) MA50447A (en)
WO (1) WO2019082037A1 (en)
ZA (1) ZA202001589B (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA3076581A1 (en) 2017-10-24 2019-05-02 Arcelormittal A method for the manufacture of a coated steel sheet
US11466354B2 (en) 2017-10-24 2022-10-11 Arcelormittal Method for the manufacture of a coated steel sheet
EP3701058A1 (en) 2017-10-24 2020-09-02 ArcelorMittal A method for the manufacture of a galvannealed steel sheet
RU2761927C1 (en) 2017-11-17 2021-12-14 Арселормиттал Method for manufacturing zinc-coated steel sheet resistant to liquid metal embrittlement
WO2020245632A1 (en) * 2019-06-05 2020-12-10 Arcelormittal A method for manufacturing a metal assembly
US20220290269A1 (en) * 2019-10-09 2022-09-15 Nippon Steel Corporation Steel sheet and method for manufacturing same
WO2022107580A1 (en) * 2020-11-17 2022-05-27 日本製鉄株式会社 Plated steel sheet for spot welding use, joining member, automotive member, and method for manufacturing joining member

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5098217B2 (en) * 2005-09-28 2012-12-12 新日鐵住金株式会社 Welded joints of galvanized steel sheets excellent in corrosion resistance and zinc embrittlement cracking resistance of welds and methods for producing the same
JP5079795B2 (en) * 2007-04-11 2012-11-21 新日本製鐵株式会社 Hot-dip hot-dip steel sheet for press working with excellent low-temperature toughness and method for producing the same
US20120100391A1 (en) 2010-10-21 2012-04-26 Posco Hot-dip galvanized steel sheet having excellent plating qualities, plating adhesion and spot weldability and manufacturing method thereof
KR20140095101A (en) * 2011-12-27 2014-07-31 신닛테츠스미킨 카부시키카이샤 Hot-dip plated high-strength steel sheet for press working with excellent low-temperature toughness and corrosion resistance, and process for producing same
WO2013161831A1 (en) * 2012-04-23 2013-10-31 株式会社神戸製鋼所 Method for producing galvanized steel sheet for hot stamping, alloyed hot-dipped galvanized steel sheet for hot stamping and method for producing same, and hot stamped component
ES2632618T3 (en) * 2013-02-12 2017-09-14 Tata Steel Ijmuiden Bv Coated steel suitable for hot dip galvanization
WO2015088523A1 (en) * 2013-12-11 2015-06-18 ArcelorMittal Investigación y Desarrollo, S.L. Cold rolled and annealed steel sheet
KR101585721B1 (en) * 2013-12-21 2016-01-14 주식회사 포스코 Galvanized steel having good weldabity and method for manufacturing the same
KR101568543B1 (en) * 2013-12-25 2015-11-11 주식회사 포스코 Galvanized steel sheet having excellent resistance to crack by liquid metal embrittlement
BR122019019513B1 (en) * 2014-07-03 2020-09-15 Arcelormittal DISCOVERED STEEL SHEET AND COATED STEEL SHEET
JP2016089274A (en) * 2014-11-04 2016-05-23 株式会社神戸製鋼所 Plating steel sheet for hot stamp
CN107127238B (en) * 2016-02-26 2019-12-27 宝山钢铁股份有限公司 Hot stamping forming method for zinc-based plated steel plate or steel strip

Also Published As

Publication number Publication date
MA50447A (en) 2020-09-02
CA3076994A1 (en) 2019-05-02
ZA202001589B (en) 2021-03-31
BR112020006128A2 (en) 2020-09-24
KR102206933B1 (en) 2021-01-25
US20200340124A1 (en) 2020-10-29
WO2019082037A1 (en) 2019-05-02
KR20200047728A (en) 2020-05-07
CN111279006A (en) 2020-06-12

Similar Documents

Publication Publication Date Title
KR102206933B1 (en) Method of manufacturing coated steel sheet, two spot welded metal sheets and their use
CA3076464C (en) A method for the manufacture of a galvannealed steel sheet
CA3059297C (en) A method for the manufacturing of liquid metal embrittlement resistant galvannealed steel sheet
US11466354B2 (en) Method for the manufacture of a coated steel sheet
CA3076581A1 (en) A method for the manufacture of a coated steel sheet
JP7394921B2 (en) Manufacturing method of coated steel plate
WO2018115946A1 (en) A method for the manufacture of a coated steel sheet
WO2018115945A1 (en) A method for the manufacture of a galvannealed steel sheet
WO2018115948A1 (en) A method for the manufacture of a coated steel sheet

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20200525

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAX Request for extension of the european patent (deleted)
RAV Requested validation state of the european patent: fee paid

Extension state: MA

Effective date: 20200525

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

RIC1 Information provided on ipc code assigned before grant

Ipc: C23C 2/02 20060101AFI20210526BHEP

Ipc: C23C 2/06 20060101ALI20210526BHEP

Ipc: C23C 2/40 20060101ALI20210526BHEP

Ipc: C25D 3/12 20060101ALI20210526BHEP

Ipc: C25D 3/22 20060101ALI20210526BHEP

Ipc: C23C 28/02 20060101ALI20210526BHEP

Ipc: C23C 14/16 20060101ALI20210526BHEP

Ipc: C25D 5/12 20060101ALI20210526BHEP

Ipc: C25D 7/06 20060101ALI20210526BHEP

INTG Intention to grant announced

Effective date: 20210618

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20211029