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
  • C23C2/14—Removing excess of molten coatings; Controlling or regulating the coating thickness
  • C23C2/24—Removing excess of molten coatings; Controlling or regulating the coating thickness using magnetic or electric fields

Definitions

• the invention relates to a method and a device for hot-dip coating of metal strands, in particular steel strip, in which the metal strand is guided vertically through a container holding the molten coating metal and through an upstream guide channel in which induction currents are induced in the coating metal by an electromagnetic traveling field. which, in interaction with the traveling electromagnetic field, cause an electromagnetic force to retain the coating metal.
• This positional instability affects on the one hand the central position of the metal strand and on the other hand also the shape of the metal strand parallel to the direction of the strand running in the guide channel.
• a slight flatness disturbance in a steel strip is also aggravated, i.e. a cross bow in the band is enlarged.
• Initial tests have shown that forces act in the magneto-hydrodynamic closure of the guide channel, which in combination with the coating temperature lead to plastic changes in the strip shape.
• S-shaped tape shape errors were also found parallel to the tape running direction. The observed waveforms of the deformation are greater than or equal to the 2nd order.
• the invention has for its object to propose measures for adjusting the position of the metal strand in the guide channel and / or in the container for the coating metal.
• the object is achieved according to the invention in that the position of the metal strand is stabilized by hydrostatic or hydrodynamic loading perpendicular to the strand surface in the container and / or in the guide channel during the strand movement.
• strip shape errors can be largely avoided and the metal strand is stabilized in its central position.
• the liquid coating metal is used to stabilize the metal strand or the strip.
• a special effect is thereby achieved in that the support takes place on the one hand and the coating metal on the other hand.
• a further improvement with regard to the strip shape errors can furthermore be achieved in that the hydrostatic or hydrodynamic stabilization of the metal strand is carried out continuously on one or more strand locations located at certain intervals on one or both sides. Due to a suitable selection of the support points, an S-shape can be created in the strip transversely to the longitudinal direction of the metal strand, which increases the moment of inertia with regard to a curvature of the strip parallel to the strip running direction to such an extent that the strip can be guided flat and even through the guide channel.
• the central, continuous positioning with simultaneous shaping can take place in such a way that the metal strand is stabilized hydrostatically or hydrodynamically at individual or pairwise opposed strand locations.
• the object is achieved on the basis of a device for hot-dip coating metal strands, in particular steel strip, in which the metal strand can be passed vertically through a container containing the molten coating metal and through an upstream guide channel in which induction currents can be induced in the coating metal by means of an electromagnetic traveling field.
• which, in interaction with the electromagnetic traveling field, exert an electromagnetic force for retaining the coating metal according to the invention solved in that hydrostatically or hydrodynamically fed support elements are arranged in the region of the container and / or the guide channel.
• One type embodying the invention consists in that the support elements are fed hydrostatically or hydrodynamically by means of the molten coating metal. This type combines part of the support effect to avoid cross-bows or other flatness disturbances and other part coating metal is applied at this point.
• the support effect can also be brought about in the form that the support element forms a feed channel connected to a metal pump for the molten coating metal, which has nozzles arranged at the outlet end.
• the coating metal stream exiting the nozzle provides support.
• the nozzle has a channel extension formed at the outlet end, which is delimited by support projections on both sides.
• the metal melt can produce a wide support surface or application surface between the support projections.
• flatness disorders such as Cross-Bows
• the support elements engage individually spaced on one or on both sides of the metal strand.
• Exemplary embodiments of the invention are shown in the drawing and are explained in more detail below.
• 3A shows a section through the container with support elements in the region of the guide channel
• 3B shows a section through the container with support elements in the container and above the bath level
• FIG. 4A shows a section through the container with a plurality of support elements.
• Fig. 4B shows a section through the container perpendicular to the section of the
• the method for hot-dip coating of metal strands 1, in particular steel strip in which the metal strand 1 is continuously passed vertically through a container 3 which holds the molten coating metal 2 and through an upstream guide channel 4 in which 2 induction currents are induced in the coating metal by an electromagnetic traveling field , which, in interaction with the traveling electromagnetic field, cause an electromagnetic force to retain the coating metal 2, provides that the metal strand 1 by hydrostatic or hydrodynamic loading perpendicular to the strand surface 1 a in the container 3 and / or in the guide channel 4 during the strand movement in its position is stabilized.
• the liquid coating metal 2 is used to stabilize the metal strand 1.
• the hydrostatic or hydrodynamic stabilization of the metal strand 1 can be at one strand location 5 (FIG. 1A) or at several (two), spaced strand locations 5 and 6 (FIG. 1B) or at three Strand positions 5,6, and 7 (Fig. 1C) and at four strand positions 5,6,7 and 8 (Fig. 1D).
• the metal strand 1 is secured hydrostatically or hydrodynamically at individual strand locations 5 (FIG. 2A) or at pairs of strand locations 5 and 6 (FIG. 2B) that are offset from one another or at several strand locations 5, 6 and 7 (FIG. 2C).
• the arrangement of the hydrostatically or hydrodynamically fed support elements 9 in the region of the container 3 and / or the guide channel 4 takes place in accordance with the configuration of FIGS. 1A-1D and FIGS. 2A-2C. Their formation depends on whether the support elements 9 are fed by means of the molten coating metal 2, which is a prerequisite for all of the embodiments described here.
• the support element 9 in each case forms a feed channel 10 which is connected to a metal pump for the molten coating metal 2 and which has a nozzle 12 at the outlet end 11. At the outlet end 11, this nozzle 12 forms a channel widening 10a which is delimited by support projections 13 and 14 on both sides.
• the support elements 9 can be arranged at the entrance area 15 of the container 3 (FIG. 3A) or in the container 3 itself (FIG. 3B).
• Additional support elements 9 can also be used above the bath level 16 of the container 3.
• the support elements 9 each engage with respect to the metal strand 1 on a left side 1b and / or on a right side 1c of the metal strand 1 in order to stabilize.
• An additional effect is that the hydrostatically or hydrodynamically operated support elements 9 can simultaneously apply coating metal 2.
• Running supply channels 10 have nozzles 12 with channel extensions 10a, from which the coating metal 2 emerges upwards and downwards. Between each of the feed channels 10 supplying the coating metal 2, a discharge channel 17 is arranged, which feeds excess coating metal 2 back to the metal pump or a storage space.
• the meniscus generated by the electromagnetic traveling field can be seen at 19.
• the width of the metal strand 1 is shown as a band and the direction of withdrawal 18 is shown from bottom to top.
• the arrangement of the main coils 20 is also visible.
• the width of the feed channel 10 also results from FIG. 4B.

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)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (5)

Families Citing this family (2)

Citations (9)

• 2000
  • 2000-03-24 DE DE2000114868 patent/DE10014868A1/de not_active Withdrawn
• 2001
  • 2001-03-20 TW TW90106438A patent/TW487740B/zh active
  • 2001-03-21 EG EG20010288A patent/EG23259A/xx active
  • 2001-03-23 AU AU2001260146A patent/AU2001260146A1/en not_active Abandoned
  • 2001-03-23 WO PCT/EP2001/003326 patent/WO2001071052A1/de active Application Filing

Patent Citations (9)

Non-Patent Citations (6)

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