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
  • B22D11/04—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
  • B22D11/041—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds for vertical casting
• • 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
  • B22D11/10—Supplying or treating molten metal
  • B22D11/11—Treating the molten metal
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
  • B22D27/003—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting by using inert gases
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/08—Alloys with open or closed pores

Definitions

• the invention relates to a continuous casting method for producing material profiles which have cavities, and a continuous casting device for carrying out such a method.
• German patent application 38 14 030 AI relates to a foam steel as a structural dressing material. This is produced by gluing together metal spherical or troughed sheet metal, which then forms a honeycomb structure.
• WO 86/06 431 and WO 88/04 586 describe methods which, although they allow good shaping for cavities in material profiles, are not particularly suitable for lightweight construction of load-bearing components.
• WO 88/04 586 describes a method and a device for the continuous casting of metal strands from refractory metals with cross-sections close to the final dimensions according to the principle of communicating tubes.
• the invention has for its object to provide a continuous casting process for the production of material profiles, in particular steel profiles, which have cavities, and a continuous casting device for performing such a method, the material weight of the profiles by introducing gas bubbles, which is preferred can be flexibly designed in terms of their position and extent and form cavities.
• cavities can be positioned in material profiles as desired, because the gas bubbles are introduced into those material strand areas where the material has a doughy structure.
• a doughy structure is understood to mean a state of the material lying between liquid melt and solidification, in which gas bubbles - possibly under high pressure - are still formed by means of nozzles or the like. let it be brought into the material. Therefore, the gas bubbles in the material strand can only move to a very limited extent, if at all, and should be avoided if a specific position and structure of the cavities is aimed for.
• the gas bubbles can largely not leave the doughy material strand area in the direction of the liquid area, but rather, as intended, form a cavity which is filled with the gas is.
• Metallic materials are preferably used as the material. det.
• the gas is preferably introduced at several points within the material strand which lie on an isothermal surface. In this way, several cavities can be created simultaneously by the inclusion of gas bubbles.
• a noble gas for example argon, is preferably used as the gas in order to avoid undesirable chemical reactions between the material and the gas which can result in a change in the material structure in the solidified state.
• step c) the gas can be supplied continuously or in pulses.
• both elongated, continuous cavities and cavities arranged one behind the other in the longitudinal direction of the material strand can be formed.
• the structure of the cavities generated can be monitored by at least one ultrasound measuring device which is arranged in the region of the running material strand.
• the outer skin of the strand of material is preferably reinforced by fibers.
• the speed of the material strand is preferably greater than the speed of buoyancy of bubbles formed from the gas.
• the introduced gas bubbles cannot escape upwards in the direction of the liquid material area.
• the rate of buoyancy is in normal case negligible small.
• the invention also relates to a continuous casting device for producing material profiles which have cavities
• a storage container for liquid material which has a closable, bottom-side outlet opening; and a cooled mold for cooling liquid material emerging from the outlet opening as a strand, the mold being arranged below the outlet opening and substantially vertically; at least one gas pipe is provided for introducing gas, and - the gas pipe has an outlet opening which, depending on the material used, is arranged in the interior of the mold in an area in which the strand of material has a pasty structure due to the cooling by the mold .
• This device ensures both a guiding of the material strand from top to bottom and an introduction of the gas bubbles in the area inside the mold in which material with the suitable, doughy structure is present.
• a control device for example a controllable valve block, is preferably provided, with which the gas introduction into the material strand can be controlled in its amount, which depends on the gas pressure used, and / or in its shape, continuously or in pulse form.
• Gas can be supplied via nozzles arranged at the outlet end of the gas pipes, the openings of which, depending on the desired cross-sectional shape for the cavities, can have, for example, a round, slit-shaped or rectangular cross-section.
• bridges can be provided in the nozzle openings in order to hold the core of the material strand.
• At least one ultrasound measuring device is preferably provided for monitoring the structure of the cavities of the running material strand.
• Electrical signals of the ultrasound measuring device which reflect the structure of the cavities, can be fed to the control device, so that, depending on the measurement results of the ultrasound measuring device, the desired structure of the cavities can be generated.
• larger voids can be formed by increasing the gas pressure in the cross section of the material strand or by expanding the gas pulse width in the strand direction, more extensive voids can be formed.
• the method and a device adapted to the material to be processed can be used to produce profiles made of light metal, non-ferrous metal or plastic, the method and device being designed according to the requirements of the materials to be processed.
• Figure 1 is a view of an embodiment of a continuous casting device, partially in section.
• 2A and 2B are a cross-sectional and a longitudinal section view of a plate-shaped material profile
• 3A and 3B are a cross-sectional and a longitudinal sectional view of a U-shaped material profile
• FIGS. 4A and 4B are cross-sectional and longitudinal sectional views of a T-shaped material profile.
• Figure 1 shows an embodiment of a continuous casting device, which is partially shown in section.
• the position of a feed line 1 from a transport container is indicated by an arrow.
• a storage container 2 is filled with liquid steel, for example, which is kept at a temperature by a heating device.
• At the bottom of the storage container 2 there is a closable outlet opening designed as a funnel, which can be opened and closed by a regulated valve 3, level control by means of an ultrasonic sensor 17 being provided.
• the reservoir 2 is surrounded by an electromagnetic agitator 4 so that the molten steel can be degassed and homogenized.
• the melt is discharged into a mold 6 which is arranged vertically under the outlet opening of the storage container 2 and which is liquid-cooled.
• the mold 6 is fastened to the stage 5 in vertically arranged slide elements.
• melt can enter the mold area at about 1400 ° C, for example, and after cooling through the mold 6 can reach a temperature of about 800 ° C at which the melt becomes pasty. Regardless of the temperatures mentioned, however, as will be explained later, mainly on the area of the melt where it shows a pasty structure.
• Tubes 7 made of a high temperature-resistant material, for example ceramic, are immersed in the melt and are connected to a valve block 14.
• a cooling device is provided if necessary.
• the gas is an inert gas, for example argon, which has no connection with the steel.
• the gas is pressure-controlled and can be controlled via the valve block 14 so that each individual tube 7 can be opened and closed in time and, if necessary, different pressures can be set.
• the gas pressure must be constantly controlled and regulated so that no steel can be pushed back into the gas lines.
• the gas is supplied via openings in the tubes 7 in an area in which the melt is in the doughy state, preferably along or near an area of the same temperature, as is indicated by an isotherm I in FIG.
• the gas bubbles 8 which are formed can thereby be positioned exactly and their expansion can be controlled, so that voids can be predetermined in the material strand.
• the mold 6 is designed and guided by means of a vertical guide 12 so that vertical oscillation with a frequency of approximately 1 Hz is possible in order to prevent the melt from caking on the mold wall and on the gas pipes 7 and the gas bubbles 8 introduced better to be able to separate from each other.
• a mounted, additional ultrasonic measuring device 15 enables an assessment of the bubble structure, whereby a water-cooled graphite mass can serve as a transmission medium. It is advantageous to arrange approx. 2 measuring devices at an angle of 90 ° to one another in order to be able to carry out a spatial assessment of the bubble structure generated.
• the electrical output signal of the ultrasonic measuring device 15 can be used to control the valve block 14, for example the gas pressure set there and the gas pulse width used there, in order to generate the desired bubble and cavity structure.
• an X-ray device can also be used to obtain information about the bubble structure.
• the gas bubbles 8 can be positioned according to the position of the gas pipes 7 and their vertical and horizontal expansion and distribution over the cross section can be controlled. The latter can be accomplished, for example, via the shape of the openings of the gas pipes 7 in connection with a corresponding gas pressure control.
• the falling and still externally cooled strand is taken over below the mold 6 by a transport device 11, the speed of which can be regulated so that an optimal process control is possible.
• the strand When the strand has reached the horizontal plane, it can be divided and the separated sections can be used for
• the sump 9 for any escaping is located below the system liquid material.
• the possible cross-sectional shapes of the material profiles produced range from plate-like structure, rectangular shape, U-shape to double-T support structure, etc.
• FIGS. 2A, 2B, 3A, 3B, 4A and 4B show the cross-sectional shapes as described above with the associated longitudinal sections, but the shape of the gas bubbles is variable.
• the entire device is controlled by a process control so that continuous production is possible.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Continuous Casting (AREA)
• Treatment Of Steel In Its Molten State (AREA)

Applications Claiming Priority (3)

Publications (2)

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• 1998
  • 1998-07-13 DE DE59801803T patent/DE59801803D1/de not_active Expired - Fee Related
  • 1998-07-13 US US09/462,741 patent/US6263953B1/en not_active Expired - Fee Related
  • 1998-07-13 WO PCT/EP1998/004348 patent/WO1999004047A1/fr active IP Right Grant
  • 1998-07-13 AT AT98939634T patent/ATE207131T1/de not_active IP Right Cessation
  • 1998-07-13 EP EP98939634A patent/EP0998589B1/fr not_active Expired - Lifetime
  • 1998-07-13 JP JP2000503252A patent/JP2001510096A/ja active Pending

Non-Patent Citations (1)

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