Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
  • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
  • B22D11/0611—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by a single casting wheel, e.g. for casting amorphous metal strips or wires
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
  • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
  • B22D11/0637—Accessories therefor
  • B22D11/064—Accessories therefor for supplying molten metal

Definitions

• the invention relates to a method for casting and a casting device for strips or foils made of metallic or metal-oxide melt, according to the preambles of claims 1 and 5.
• methods and devices for the direct casting of metal melts onto moving cooling body known, usually using a cooling drum or a moving cooling belt.
• the molten metal is fed to the surface of the cooling drum or the cooling belt via a nozzle-like discharge element.
• the most important process parameters for the casting process are the speed of movement of the heat sink surface relative to the casting nozzle, the heat dissipation from the strip to the heat sink and, as a further important parameter, the nozzle geometry.
• the width of the pouring slot in the casting direction has a decisive influence on the casting process.
• the geometry of the pouring slot has also been given considerable importance in the development to date. Accordingly, efforts to improve the casting process have also focused on the design and dimensioning of the nozzle opening and on the distance between the nozzle opening and the heat sink surface. Practically all known proposals have in common that the metal melt flows by gravity from a casting container into the nozzle and the pouring slit. This gravitational melt inlet was supported in the new strip casting technology at most by a controllable pressure system. For this reason, considerable restrictions had to be observed when dimensioning the nozzle opening and the area between the nozzle opening and the heat sink surface in order to ensure perfect casting and to prevent uncontrolled leakage or freezing of the melt in the pouring slot before the actual casting process began.
• DE-OS 3 411 466 discloses a method for producing thin metal strip, in which the application angle between the flow direction of the melt emerging from the nozzle and the casting surface between see should be 20 and 80 degrees.
• a nozzle configuration has been proposed according to DE-OS 3 442 009, in which a plurality of nozzle slots are arranged one behind the other in the casting direction. This should result in thick bands by sequential multiple application of melt at a suitable spacing of the nozzle slots from one another and with a suitable nozzle slot width.
• melt feed device is also intended to enable the production of larger casting formats, in particular a multiplication of the range that can be produced.
• the casting process can be controlled very precisely and reliably.
• the melt intermediate vessel can be arranged above or below the pouring nozzle. This results in optimal conditions at the start of pouring and at the same time a long pouring time can be guaranteed.
• the new process and the new nozzle device not only thicker strips can be produced.
• belts can be changed without changing the metal feed system state of the art multiple widths are produced.
• the nozzle itself is of simple construction and the dimensioning of the pouring slot can be designed more freely compared to the prior art.
• the melt can be fed to the pouring nozzle by gravity, whereby the static pressure can be kept constant via a level control in the intermediate vessel.
• the start of pouring can be determined by means of a flow control device in the intermediate vessel. According to one embodiment, it is particularly advantageous if the melt is pressed up into the pouring or intermediate vessel below the pouring nozzle by means of gas pressure from a level of the bath level in the pouring or intermediate vessel. With this solution, the pouring slot remains unaffected until the start of pouring.
• the flow rate of the melt into the pouring nozzle is linked in particular to the cross section of the strip produced. For strips with a thickness of less than 0.3 mm, it is recommended to set a flow rate of the melt in the tubular nozzle body in front of the area of the pouring slot to a maximum of 2 m / sec, preferably to a maximum of 0.8 m / sec.
• the cross section of the tubular pouring nozzle can be oval, rectangular, polygonal, etc. An advantageous production and a low flow resistance is ensured if the tubular pouring nozzle has a round cross section.
• a one-sided feeding of the melt into the pouring nozzle can basically be designed in different ways.
• a particularly advantageous embodiment is an L-shaped tubular body as a pouring nozzle, which is immersed in a melt bath with one leg and is separated from the melt vessel as a casting system part.
• a U-shaped tubular body which has a pouring slit in the central transverse leg and, with its two parallel legs, dips into a melt vessel.
• the slot width can e.g. converge in the direction of flow, etc.
• the production of strips with a predetermined, amorphous and / or crystalline structure, surface structure, nominal strip thickness, etc., which can be the same or different over the strip width, is considered here.
• a trouble-free melt flow through the pouring slot on the heat sink is of great importance for the quality of the strip produced.
• Quality problems arise in particular in the case of tapes of the order of 0.01-0.3 mm thickness, particularly in the case of tapes with a tape width of more than 80 mm.
• the width of the pouring slot is 20 to 50 times, preferably 20 to 30 times, the nominal thickness of the strip to be cast.
• the distance between the pouring nozzle and the moving heat sink can be 0.05-0.5 mm, preferably 0.1 mm-0.2 mm.
• a uniform band quality at the start of casting can be achieved if the casting weight is quickly equal meter is adjustable.
• the position of the pouring nozzle along the at least partially curved heat sink or the angular position of the heat sink surface with respect to the horizontal can be selected at a first contact point between the melt and the heat sink after the nozzle emerges .
• other casting parameters such as strip thickness, composition of the melt and the resulting physical properties, such as viscosity, surface tension, etc., are decisive for determining the position of the casting nozzle relative to the angular position of the heat sink surface.
• the deflection angle of the melt between the outflow direction in the pouring slot and the strip withdrawal direction can also be adjusted.
• This angle of deflection can e.g. between 30 and 120 degrees, preferably between 60 and 100 degrees. Both the position of the pouring nozzle to the angular position of the heat sink surface and the deflection angle of the melt can be optimally adapted to the casting parameters and the product to be produced.
• 1 is a side view, partly in section, of a casting device with a nozzle that can be separated from the casting vessel
• 2 shows a vertical section through a second exemplary embodiment, with a nozzle gap directed from one side onto a casting drum
• FIG. 3 is a plan view, partly in section along the line III-III of FIG. 2,
• FIG. 4 + 5 views on pouring nozzles
• Fig.6A + 6B diagrams of thickness measurements for a film according to the invention and a conventionally produced
• Fig. 7 + 8 schematic representations of melt deflections when hitting different heat sinks.
• a casting device for tapes or foils made of metallic or metal oxide melt is shown schematically.
• a rotating drum is used as the moving heat sink 6.
• a pouring nozzle 3 is arranged at a certain distance A from the pouring surface of the heat sink 6.
• the pouring nozzle 3 has a lateral melt inflow from a pouring container 1, also called an intermediate vessel, which in turn can be fed from a storage container by a pouring jet 8.
• the pouring nozzle 3 is further provided with a pouring slit 4, which is arranged in its longitudinal extent L axially to the pouring nozzle 3 and essentially transversely to the direction of movement 21 of the surface of the heat sink 6.
• the pouring slot length L corresponds to the bandwidth to be cast.
• the pouring nozzle has an essentially round, tubular cross section.
• the one-sided lateral feed of the melt is connected to the casting nozzle 3 via a coupling 10. 2 and 3, the same parts are provided with the same reference numerals.
• An outer tubular surface 22 in the area of the pouring slit 4 is flattened in order to extend the spacing gap A in the direction of movement 21 of the heat sink 6.
• an L-shaped tubular body with a right angle is used as the pouring nozzle 3.
• the vertical tube part 23 lying in front of the section in FIG. 2 and drawn in dash-dot lines plunges into a melt bath of a pressure-tight casting container in a plane 24. The melt can be pressed from the casting container into the casting nozzle 3 by means of a pressure P on the melt bath.
• a width 26 of the pouring slot 4 can, depending on the chosen casting parameters and the casting product, be between 20 and 50 times, preferably between 20 and 30 times, the nominal thickness 27 of a cast strip 28.
• the spacing gap A between the surface 22 of the pouring nozzle 3 and the moving heat sink 6 can be between 0.05 mm and 0.5 mm, for thin strips preferably between 0.1 mm and 0.2 mm.
• the pouring slit 4 ends a length 30 in front of a pipe end cover 31.
• the longitudinal extent of the pouring slit 4 is therefore only a fraction of the length of the tubular pouring nozzle 3.
• the end cover 31, which is attached opposite the feed side, has a vent hole 11 provided, from which the air can escape in a controlled manner during casting.
• FIGS. 4 and 5 show exemplary embodiments of pouring nozzles 40 and 50, the pouring nozzle 40 tapering in the feed direction of the melt.
• the width of a pouring slit 52 converges in the feed direction of the melt.
• melt 33 By pressing P on the bathroom Mirror in the plane 24 below the pouring nozzle 3, melt 33, as arrow 34 shows, is pressed up through the vertical tube part 23 into the pouring nozzle 3.
• the melt 33 is in the pouring nozzle 3 until just before entering the pouring slot 4 substantially axially to the tubular pouring nozzle 3 (arrows 35), or to put it another way, transversely to the outflow direction (arrow 36) in the pouring slot 4.
• the feed direction 35 is at the same time transverse to the strip take-off direction 37.
• the strip solidifies essentially in the gap A by removing heat from the moving heat sink 6 from one side of the strip.
• a statically calculated pressure on the melt in a plane 39 of the pouring slit 4 during the casting operation is set to 0.1-0.2 bar.
• the inflow speed of the melt is to be limited to 2 m / sec, preferably to 0.8 m / sec, in front of the area of the pouring slit 4.
• FIG. 7 and 8 schematically illustrate two examples with different angular positions of the heat sink surface in the region of the pouring slot.
• 70 and 80 represent a flat or curved part of a band-shaped or drum-shaped heat sink.
• a direction of outflow 71 from a pouring slit of a pouring nozzle is deflected in a strip withdrawal direction 72 by an acute angle 73, for example between 60-89 degrees.
• a first cooling section after the pouring slot is horizontal.
• a melt is deflected from an outflow direction 81 from a pouring nozzle into an arcuate strip withdrawal direction 82 by a right angle 83.
• a first cooling section after the pouring slit is rising and curved in this example. If desired, the first cooling section can also be arranged at a sloping angular position of the heat sink surface.
• the casting product is strips or foils with a largely adjustable and extremely uniform thickness.
• the uniform thickness of the tapes or foils produced can be verified by measurements.
• 6A shows the course of a measurement curve of the material thickness over the gap length L for a product which was produced according to the invention.
• 6B shows the corresponding course for a comparison product produced by a known method.
• a tubular nozzle with an inner diameter of 15 mm and a spout slot width of 1.5 mm was moved.
• the pouring slot width was only 0.4 mm.
• the casting speed was 25 m / sec in both processes.
• the melting speed in the pipe nozzle in front of the area of the pouring slot was calculated with a density of the melt from 6.7 kg / dm 3 to 0.424 m / sec.
• Fig. 6A has a substantially more uniform thickness than the tape according to a known method in
• the pouring nozzle is usually made from high-quality refractory materials such as SiO 2 glass, quartz, etc. It is of particular interest to keep the tubular glass nozzle cross-section and the wall thickness small even with larger bandwidths in order to achieve low manufacturing costs. With a clear cross-sectional area of the Nozzle tube of, for example, 180-250 mm 2 , for example, strips of 100 mm width can be produced. A ratio is calculated from this
• one to three times the value of the bandwidth in mm can be used to select the clear nozzle tube cross section in mm 2 .

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Continuous Casting (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=4266595

Family Applications (1)

Country Status (5)

Cited By (4)

Families Citing this family (2)

Citations (3)

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• 1986
  • 1986-09-30 CH CH3932/86A patent/CH671716A5/de not_active IP Right Cessation
• 1987
  • 1987-09-29 WO PCT/CH1987/000126 patent/WO1988002288A1/de not_active Application Discontinuation
  • 1987-09-29 EP EP87906060A patent/EP0295270A1/de not_active Ceased
  • 1987-09-29 US US07/246,665 patent/US4913219A/en not_active Expired - Fee Related
  • 1987-09-29 JP JP62505584A patent/JPH01501295A/ja active Pending

Patent Citations (3)

Non-Patent Citations (4)

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