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
  • B22D11/0622—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by two casting wheels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D43/00—Mechanical cleaning, e.g. skimming of molten metals
  • B22D43/005—Removing slag from a molten metal surface

Definitions

• the invention relates to a method for producing a metal strip by continuously pouring molten metal between two casting rolls of a band casting machine, with side seals arranged in the end area of the casting rolls, a melt pool surface being formed during the casting, and a device for carrying out the process.
• the present invention is based on the object of proposing a method of the type mentioned at the outset and an apparatus for carrying out the method, which allow simple and reliable removal or channeling of the inclusions or impurities even in the case of longer casting times. According to the invention, this object is achieved by a method having the features of claim 1 and by a device having the features of claim 6.
• the slag can be pushed in a simple manner towards the side seals, where it then solidifies in the area of the banding and is later easily removed or possibly removed.
• FIG. 1 shows two casting rolls of a roll band casting machine with a metal melt bath in between, with part of a pouring device, and with a device for rejecting slag arranged above the melt bath;
• Fig. 2 shows the arrangement of Figure 1 in longitudinal section, corresponding to a section along line II-II in Fig. 1.
• Figure 3 seen the device for rejecting slag from below.
• FIG. 4 shows a section from A in FIG. 2 on an enlarged scale
• FIG. 5 shows a section labeled C from FIG. 1 on an enlarged scale
• FIG. 6 shows a section through the device for rejecting slag according to line VI-VI in FIG. 2; and Fig. 7 shows a lower part of the pouring device in cross section.
• Fig. L shows schematically two casters 1, 2 rotatable about horizontal axes, the directions of rotation of which are denoted by D ls D 2 .
• the liquid metal is poured between the two casting rolls 1, 2 and two side seals 3 (see FIG. 2) arranged in the end region of the casting rolls 1, 2 via a pouring device 6.
• the container 5, the pouring device 6 and a cooling box 8 comprising the casting rolls 1, 2 and the side seals 3 enclosing the housing box 7 are only indicated in FIGS. 1 and 2.
• the melt pool is designated by 4 in FIGS. 1 and 2, its surface by 4a.
• the metal strip produced is led away through a passage gap 9 between the two, cooled casting rolls 1, 2 in the direction of arrow B according to FIG. 1.
• the exit plane of the metal strip corresponds to the middle plane E of the melting bath 4, in which the pouring device 6 also lies.
• the transition edges of the casting roll surface / molten bath surface are identified by K1, K2 (FIGS. 1 and 5 to 7).
• the pouring device 6 comprises, in a manner known per se, a vertical pouring tube part 10 which projects downward from the bottom of the container and a horizontal, box-shaped pouring tube part 11; the latter is indicated in FIG. 2 and, in one possible embodiment, is also shown in cross section in FIG. 7.
• the horizontal pouring tube part 11 extends practically over the entire length of the pouring rollers 1, 2 up to the side seals 3 and has two longitudinal channels 15, 16 shown in FIG. 7, of which the lower longitudinal channel 15 with a central inlet opening 17 of the vertical pouring tube part 10 connected is.
• the melt flowing into this lower longitudinal channel 15 is initially distributed over its entire length before it reaches the upper longitudinal channel 16 via a number of opening pairs 17 connecting the two longitudinal channels 15, 16 and distributed at equal intervals, from which it then passes through at an angle Above, towards the circumference of the two casting rolls 1, 2, directed openings or pairs of openings 19 emerge.
• These openings or pairs of openings 18 - like the connecting openings 17 - are evenly distributed over the entire length of the upper longitudinal channel 16, and the melt flows out of these openings 18 in approximately equal amounts uniformly, distributed over the entire length.
• any solid particles in the melt can advantageously be deposited.
• the pouring device 6 is now assigned a device 25 for rejecting slag, as will be described below.
• a sleeve 26 consisting of a heat-resistant material is fastened above the melting bath 4 an annular gas chamber 27, which can be seen in particular from FIGS. 4 and 5 and is concentric with the vertical pouring tube part 10, into which a gas supply line 28 (FIGS. 2, 3 and 4) opens.
• Inert gas argon, nitrogen or a mixture
• heated to approx. 200-300 ° C. is preferably supplied as the gas under slight pressure, and this blowing can be carried out continuously, intermittently or pulsatingly.
• An annular bottom 29 of the sleeve 26 delimiting the gas chamber 27 at the bottom is inclined downwards and in the direction away from the vertical pouring tube part 10, towards the side tenabichtung 3 directed, small openings 30 are provided, from which the gas is blown in 30a jets on the melt surface 4a (see. Fig. 2, 3, 4 and 5). If necessary, three openings 30 each face the two side seals 3.
• the molten bath surface 4a there are also two elongated hollow bodies 35, 36 which extend along the casting rolls 1, 2 or the transition edges K1, K2 (casting roll surface / molten bath surface) and which, for example, have a stiffening 37 (or several stiffeners) with one another or are connected to the sleeve 26.
• the interior of the hollow bodies 35, 36 forms gas channels into which gas is in turn supplied under pressure via a gas supply line 41, 42 and through in the hollow bodies 35, 36 (or in the bottom parts 35b, 36b thereof, see FIGS. 5 and 6) existing openings 45, 46 (Fig. 2, 5 and 6) is blown onto the molten bath surface 4a.
• Each hollow body 35, 36 (or each base part 35b, 36b) has a number of downwardly directed openings 45 distributed uniformly over the entire length, from which exit rays 45a emerge, which are in a plane essentially perpendicular to the molten bath surface 4a lie and reach the melt pool surface 4a in the vicinity of the transition edges K1, K2. As mentioned, these openings 45 are distributed over the entire length of the hollow bodies 35, 36, that is to say are also present in the central region adjacent to the sleeve 26.
• each hollow body 35, 36 is provided with a further number of outlet openings 46 directed obliquely downwards in the direction of the middle plane E of the melting bath 4 and at the same time towards the respective next side seal 3, which, however, are uniformly distributed over only part of the total length and are absent in the central area adjacent to the sleeve 26.
• Those blown onto the molten bath surface 4a from these outlet openings 46 Gas jets are designated 46a in Figs. 2, 4 and 6. 3 also indicates how these rays 46a touch the melt pool surface 4a.
• the gas jets 46a directed obliquely downward and causing the slag repulsion towards the side seals 3 are also directed towards the central plane E of the molten bath 4 counteracts the floating of the slag on the casting roll surfaces in a particularly preferred manner.
• a kind of protective wall is formed by the gas jets 45a directed towards the melt pool surface 4a in a vertical plane, or a wave block is implemented.
• the gas injection according to the invention can also have a positive influence on the surface of the molten bath 4a, for example its flattening or calming.
• the pouring device 6 itself can also have gas openings or gas channels from which gas is blown out in such a way that a surface flow which causes the slag rejection and / or influences the melt pool surface 4a is produced.
• the horizontal pouring tube part 11 can have an upper part protruding from the molten bath 4
• the upper part 51 which is provided with a gas channel 52 running parallel to the longitudinal channels 15, 16 for the melt.
• the upper part 51 also has a plurality of gas outlet openings 55, which are distributed over the entire length of the pouring tube part 11 and are arranged in pairs and in mirror image to the middle plane E of the melting bath 4, and are directed obliquely downwards from the gas channel 52 to the melting bath surface 4a and to the casting rolls 1, 2 are.
• the gas jets 55a emerging from these outlet openings 55 the melt bath surface 4a can be smoothed, so to speak, at the points influenced by the melt outlet (openings 18).
• the already mentioned downward gas jets 45a in front of the transition edges K1, K2 in turn protect the casting roll surfaces from the slag being washed away.
• the gas jets 55a emerging here could also contribute to the slag removal according to the invention. These could even replace the oblique gas jets 46a emerging from the hollow bodies 35, 36 and directed towards the side seals 3, so that instead of the hollow bodies 35, 36 only simple gas lines 58 are included downward outlet openings 45 could be used to protect the casting roller surfaces, as indicated in FIG. 7.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Continuous Casting (AREA)
• Rolls And Other Rotary Bodies (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=4568224

Family Applications (1)

Country Status (6)

Families Citing this family (4)

Family Cites Families (4)

• 2001
  • 2001-12-10 CH CH02252/01A patent/CH695600A5/de not_active IP Right Cessation
• 2002
  • 2002-12-06 AT AT02787916T patent/ATE336315T1/de not_active IP Right Cessation
  • 2002-12-06 WO PCT/EP2002/013849 patent/WO2003049888A2/fr active IP Right Grant
  • 2002-12-06 AU AU2002352223A patent/AU2002352223A1/en not_active Abandoned
  • 2002-12-06 DE DE50207883T patent/DE50207883D1/de not_active Expired - Lifetime
  • 2002-12-06 EP EP02787916A patent/EP1450972B1/fr not_active Expired - Lifetime

Non-Patent Citations (1)

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