Classifications

• • 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
• • 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
  • C23C2/006—Pattern or selective deposits
  • C23C2/0064—Pattern or selective deposits using masking layers
• • 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
  • C23C2/26—After-treatment
• • 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
• • 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
  • 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
  • C23C2/405—Plates of specific length

Definitions

• the invention relates to a method for manufacturing a single sided coated metal strip and to the single sided coated metal strip thus produced.
• the invention further relates to a laminate comprising the single sided coated metal strip.
• Coatings are generally applied to improve the surface properties of a substrate.
• metallic coatings may be applied by galvanising to protect the substrate from corrosion.
• Galvanising is the process of applying a protective zinc or zinc alloy coating on a metal substrate such as iron, steel or aluminium.
• Methods for galvanising are known and include hot-dip galvanising, electrogalvanising and physical vapour deposition (PVD).
• PVD physical vapour deposition
• aluminium based coatings may be applied by hot-dip aluminising or by electroplating.
• Organic and/or inorganic coatings may also be applied to improve the appearance and/or adhesion properties of a substrate and/or to protect a previously applied metallic coating. Such coatings may be applied on both sides of a metal strip by roller coating or by spray coating.
• a further disadvantage relates to the relatively expensive manufacturing route, which comprises the step of passing an electric current between an anode (zinc) and a cathode (steel substrate).
• Hot-dip galvanisng comprises the step of immersing a metal substrate in a bath of molten zinc or zinc alloy, such that each surface of the metal substrate is coated.
• methods for producing single sided galvanised steel by hot-dip galvanising are also known.
• a colloidal silica coating is provided on one surface of a steel sheet or strip prior to immersing the coated sheet or strip in a hot-dip galvanising bath in order to prevent the zinc adhering to the coated surface. After galvanisng, the colloidal silica coating is removed. Since an additional process step is required to remove the coating, the speed at which single sided galvanised steel substrates are manufactured is reduced.
• the colloidal silica coating may delaminate exposing the 'uncoated' surface to the molten zinc.
• a method for producing single sided galvanised steel by hot-dip galvanising is also known from US4120997, wherein a steel sheet or strip is differentially hot-dip coated to provide a metallic zinc coating on one surface of the strip and an ultra thin metallic zinc film on the other surface. The zinc film is then heated to form a zinc-iron intermetallic which is subsequently removed. Not only does this require an additional process step to remove the temporary coating, it also results in a substantial waste of zinc, which in recent years, has become increasingly expensive.
• Another object of the invention is to increase the volume and rate at which single sided coated metal substrates may be manufactured.
• Further objects include providing a less expensive method for providing a single sided coated metal substrate and providing a single sided coated metal substrate that is suitable for use in metal-polymer-metal laminates.
• a metal strip stack comprising a first metal strip and a second metal strip, the first metal strip having a first inner surface and a first outer surface and the second metal strip having a second inner surface and a second outer surface;
• the first inner surface and the second inner surface are prevented from coming into contact with the coating material.
• pre-treatment of the first inner surface and the second inner surface i.e. with a protective temporary coating, is not necessary.
• the requirement to remove a temporary coating formed prior to or during the coating step is also avoided. Since the method of the invention does not require the application and/or removal of a protective temporary coating, the rate at which single sided coated metal strips are manufactured may be increased.
• the method of the invention also has the advantage that the number of single sided coated metal strips produced may be increased by a factor of two relative to conventional methods, since two metal strips are coated in the coating step instead of one.
• the coating material is a metal or metal alloy comprising zinc and wherein the zinc alloy comprises more than 50 % zinc and one or more of Mg, Al, Si, Mn, Cu, Fe and Cr.
• Zinc alloys selected from the group consisting of Zn-Mg, Zn-Mn, Zn-Fe, Zn-AI, Zn-Cu, Zn-Cr, Zn-Mg-AI and Zn-Mg-AI-Si are preferred and afford additional corrosion protection to the underlying metal strip by sacrificial protection.
• the coating material is a metal or metal alloy comprising aluminium and wherein the aluminium alloy comprises more than 50% aluminium and one or more of Mg, Zn, Al and Si.
• Metal strips provided with aluminium coatings afford improved corrosion resistance, whereas aluminium alloys such as Al-Si alloys also improve adhesion to the metal strip and protect the metal from high temperature oxidation in high temperature applications such as hot-press forming.
• the coating material is applied by physical vapour deposition, electroplating or by hot-dip coating, preferably hot dip galvanising or by hot-dip aluminising.
• electroplating and PVD may be used to provide single sided coated metal strips, the use of hot-dip coating is preferred since the overall cost of the manufacturing process may be significantly reduced.
• the coating material comprises an organic and/or non-metallic inorganic material that is applied by roller coating or spray coating.
• the metal strip comprises aluminium or steel.
• Aluminium and low carbon steel are particularly suitable for use as a skin of a metal-polymer-metal laminate.
• the steel may also be selected from the group consisting of dual phase steel, transformation induced plasticity steel, twinning induced plasticity steel, quenched and partitioned steel, boron steel, interstitial-free steel, bake hardenable steel and high strength low alloy steel. These steels exhibit improved strength and ductility characteristics that are particularly attractive to the automotive industry where weight reduction is becoming an increasingly important issue.
• a preferred steel composition comprises 0.04 - 0.30 % C, 1.0 - 3.5 % Mn, 0 - 1.0 % Si, 0 - 2.0 % Al and 0 - 1.0 % Cr.
• Other elements can be present, such as V, Nb, Ti and B, but usually in a small amount.
• the steel may also be an electrical steel for use in electrical transformers.
• the coated first metal strip and the coated second metal strip may be coiled.
• the separated coated strips can be used in a subsequent manufacturing process without being coiled.
• the coated first metal strip and the coated second metal strip may be fed into a laminating line, preferably a belt laminating line, and laminated with a polymeric layer provided therebetween. The laminate can then be coiled or blanked.
• the coated metal strips can be coiled after separation and then fed into the laminating line as above.
• the metal strip stack has a width dimension of at least 1250 mm, preferably between 1250 and 2100 mm. Metal strips having such dimensions are particularly suitable for subsequent use in the automotive and construction sectors.
• the thickness of the first metal strip differs from the thickness of the second metal strip.
• Such an asymmetric metal strip stack is particularly advantageous when the single sided coated metal strips are to be used in the production of metal-polymer-metal laminates since the thicker of the two coated single sided coated metal strips provides improved dent resistance to the laminate.
• the thickness of the metal strip stack is reduced before and/or after coating of the metal strip stack.
• a metal strip stack thickness between 0.1 and 10 mm is preferred.
• the thickness of the stack may be reduced prior to coating the stack, which has the advantage that only a single milling operation is required to obtain the desired thickness of the first metal strip and the second metal strip.
• a metal strip stack having a total thickness of 1.4 mm comprising two metal strips, each having a thickness of 0.7 mm may be milled down to a stack thickness of 0.3 mm in order to obtain two 0.15 mm thick metal strips.
• the coated stack it is also possible to subject the coated stack to a single milling operation or to subject the coated first metal strip and the coated second metal strip to two separate milling operations in order to obtain the desired thickness.
• the thickness of the first metal strip and the second metal strip can be reduced in two separate milling operations prior to providing the metal strip stack.
• subjecting the stack to a milling operation instead of milling the first metal strip and the second metal strip independently means the thickness of each metal strip can be reduced to a greater extent.
• the thickness of the metal strip stack is reduced by cold-rolling and/or by hot-rolling.
• the metal strip stack comprises a metal or metal alloy substrate situated between the first metal strip and the second metal strip. This allows the thickness of the metal strip stack to be reduced to a much greater extent relative to a stack consisting of the first metal strip and the second metal strip.
• a further metal strip is suitable for this purpose.
• the metal or metal alloy substrate may also act as a filler material that fills openings between strip edges caused by undulations, i.e. wavy regions along the strip edge. Soft metals are particularly preferred as filler substrates although suitable polymeric materials can also be used.
• At least a portion of the first metal strip and at least a portion of the second metal strip are joined together. This may be achieved by providing an adhesive or a layer of a soft metal between at least the edges of the first metal strip and the second metal strip.
• the first metal strip and the second metal strip may be welded by laser welding or resistance welding.
• the resistance welding is seam welding such as mash seam welding. If the first metal strip and the second metal strip are joined together by welding, then it is preferred to remove the weld after coating, preferably by slitting, to enable separation of the coated strips. Similarly, edge trimming of the coated metal strip stack or of the coated metal strips after separation may be necessary if the edges of the stack are not properly coated.
• Joining the first metal strip and the second metal substrate has the advantage that zinc or zinc alloy is prevented from substantially contacting the first inner surface and the second inner surface. Moreover, water vapour in the air is prevented from being drawn between first metal strip and the second metal strip by capillary action. Thus, the potential for corrosion to occur at the first inner surface and the second inner surface is avoided or at least reduced.
• the first inner surface and/or the second inner surface is provided with a non-stick coating prior providing the metal strip stack.
• a non-stick coating prior providing the metal strip stack.
• separating the coated metal strips is relatively straightforward, it may be desirable to provide an additional coating having non-stick properties to facilitate separation of the coated first metal strip and the coated second metal strip.
• the coating does not substantially thermally degrade when hot-dip coating the stack. Suitable non-stick materials include Si0 2 .
• the second aspect of the invention relates to a single sided coated metal strip produced according to the method of the first aspect of the invention, which coated metal strip has a first major surface and a second major surface wherein the coating material is present on the first major surface and wherein at least a portion of the second major surface is not coated with the coating material.
• the thickness of the metal strip of the second aspect of the invention is between 0.08 and 2 mm, preferably between 0.1 and 0.3 mm, more preferably between 0.12 and 0.19 mm.
• Metal strips of the present invention having a thickness between 0.08 and 2 mm are suitable for producing products having a wide range of applications, particularly in the automotive and aerospace sectors.
• the above metal strips are suitable as 'skins' for use in metal-polymer-metal laminates, which laminates are suitable for automotive body work parts such as outer panels.
• a thickness between 0.12 and 0.19 mm is particularly suitable for this purpose.
• the coated metal strip comprises an organic coating and/or a non-metallic inorganic coating on the coating material to afford additional corrosion protection to the coated metal strip and/or to improve its aesthetic appearance.
• the organic and/or non-metallic inorganic coating may be provided on the surface not coated with the coating material to improve adhesion, for instance, with a polymer core of a metal-polymer-metal laminate.
• Suitable organic coatings comprise epoxies and epoxies containing polypropylene particles, whereas preferred inorganic coatings comprise silanes, chromates and chromate free- coatings based on titanium, manganese or phosphates.
• the third aspect of the invention relates to a laminate comprising a first metal skin, a second metal skin and a polymeric core layer disposed therebetween wherein the first metal skin and/or the second metal skin is formed from the coated metal strip according to the second aspect of the invention, and wherein the coating material is facing away from the polymeric core layer.
• the polymeric core layer has a thickness between 0.5 and 2.5 mm.
• a thickness is particularly suitable for automotive body work parts such as outer panels. Such panels are sufficiently rigid to satisfy body work part requirements for motor vehicles and exhibit good noise dampening properties.
• the thickness of the first metal skin and/or the second metal skin is between 0.1 and 0.3, preferably between 0.12 and 0.19 mm.
• Figure 1 shows a general method for manufacturing the single sided coated metal strip of the invention wherein a first metal strip (1 ) and a second metal strip (2) are provided and stacked to form a metal strip stack (3).
• the metal strip stack is then coated by immersing the stack in a hot-dipping bath containing a molten metal or metal alloy (4).
• the coated stack is then removed from the bath and separated in a separating section (5) to provide two single sided metal or metal alloy coated metal strips (6).
• the single sided metal or metal alloy coated metal strips are then coiled at a coiler (7).
• Figure 2 shows a simplified view of:
• the metal strip stack (3) comprising the first metal strip and the second metal strip wherein the first inner surface and the second inner surface are facing each other and are protected from contacting the metal or metal alloy during hot- dipping;
• a low carbon steel strip was cut into two 200 x 120 x 0.7 mm samples. Each steel strip was decreased in an alkaline bath and then cleaned with a suitable organic solvent such as acetone. The edges of each steel strip were then mechanically grinded before the steel sheets were stacked and subsequently spot welded along the rolling direction. The thickness of the stack was then reduced from 1.4 mm to 0.3 mm by cold rolling the stack in passes of ⁇ 0.2 mm.
• the steel stack having a reduced thickness of 0.3 mm was then annealed in accordance with a common hot-dip galvanising cycle to obtain a stack temperature of approximately 1000 ° C.
• the stack was then cooled to 440 ° C and subsequently hot-dip galvanised.
• the spot welded edges were then removed by slitting and the stacked sheets separated to obtain two single sided galvanised steel sheets having a thickness of 0.15 mm.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Coating With Molten Metal (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=48699719

Family Applications (1)

Country Status (1)

Citations (15)

• 2013
  • 2013-06-20 WO PCT/EP2013/001816 patent/WO2013189601A1/fr not_active Ceased

Patent Citations (15)

Similar Documents

Legal Events