US3372731A - Method of withdrawing the strand from a continuous casting machine - Google Patents

Method of withdrawing the strand from a continuous casting machine Download PDF

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Publication number
US3372731A
US3372731A US483525A US48352565A US3372731A US 3372731 A US3372731 A US 3372731A US 483525 A US483525 A US 483525A US 48352565 A US48352565 A US 48352565A US 3372731 A US3372731 A US 3372731A
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United States
Prior art keywords
strand
dummy bar
rolls
withdrawing
mould
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Expired - Lifetime
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US483525A
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English (en)
Inventor
Pauels Heinrich
Meier Walter
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Schloemann AG
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Schloemann AG
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
    • B25B15/00—Screwdrivers
    • B25B15/02—Screwdrivers operated by rotating the handle
    • B25B15/04—Screwdrivers operated by rotating the handle with ratchet action
    • 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
    • B22D11/08—Accessories for starting the casting procedure

Definitions

  • FIG-4 IggVENTgRS ATTORNEYS United States Patent Office 3,372,?31 Patented Mar. 12, 1968 3,372,731 METHOD OF WITHDRAWING THE STRAND FROM A CONTINUUUS CASTING MACHINE Heinrich Panels, Dusseldorf-Lohausen, Germany, and Walter Meier, Winterthur, Switzerland, assignors to Schloemann Ahtiengeselischaft, Dusseldorf, Germany, and Concast A.G., Zurich, Switzerland Filed Aug. 30, 1965, Ser. No. 483,525 Claims priority, application Germany, Aug. 29, 1964, Sch 35,703 5 Claims. (Cl.
  • ABSTRACT OF THE DISCLOSURE During withdrawal of the dummy bar head and the strand attached thereto from a continuous casting mold, an abrupt dimensional discontinuity interrupts smooth withdrawal when the discontinuity enters a withdrawal roll. To prevent this, the applicant reduces the abrupt discontinuity by shaping of the dummy bar head and allowing the discontinuity to enter a smoothing roller in such manner as to make the transition from head to strand smooth.
  • This invention relates to a method of withdrawing the strand from a continuous casting machine, in which liquid metal is poured into a cooled mould whose exit end is closed by a dummy bar and the strand is withdrawn from the mould by the dummy bar engaged by withdrawing rolls, and an apparatus for performing the method.
  • the invention is advantageously applied to the casting of slabs.
  • the mould When continuous casting machines are started up, the mould is closed by a dummy bar whose bottom end is in the range of operation of a set of withdrawing rolls. To ensure that the dummy bar head does not jam in the cross sectional zone of the mould and scrape the mould wall, its cross section must be made smaller than the free cross section of the mould.
  • the resultant gap between the mould wall and the dummy bar head will vary with the size of the strand and may the as much as mm. and is closed by a sealant to prevent any passage of liquid material.
  • a sealant to prevent any passage of liquid material.
  • the latter is covered by an asbestos sheet.
  • the dummy bar head is formed with recesses to receive bars or rails which connect the solidified strand with the dummy bar.
  • the smaller cross section of the dummy bar head as compared with the cross section of the mould cavity means that there is an abrupt change of cross section between the casting and the dummy bar head and this results in scams or joints.
  • These are very unfavorable as regards introduction of the strand into the withdrawing rolls because they obstruct such introduction or catch against the withdrawing rolls and make introduction impossible.
  • Conditions are very unfavorable in continuous casting machines in which the strand is guided in an arcuate guiding system after the mould, since the shape of the arc causes the dummy bar head to bear unilaterally against the mould wall so as to form a unilateral seam. The difference between strand and dummy bar head thickness on this unilateral seam prevents the strand from being engaged by withdrawing rolls.
  • the straightening process carried out in the combined withdrawing and straightening unit usually used in arcuate machines of this kind causes a bending force to be exerted on the dummy bar head and this is transmitted to the connecting elements between the dummy bar head and the strand.
  • the increased traction due to the seam and the bending force usually cause the connecting elements to break or at least cause the withdrawing rolls to slip.
  • Such slip is increased by the fact that there is a shrinkage gap between the dummy bar head and the beginning of the strand and this gap is further increased by the asbestos sheet.
  • the effective difference between strand and dummy bar head thickness on the seam forming during casting at the connection between the dummy bar head and the beginning of the strand is reduced for entry into the withdrawing rolls.
  • This reduction of the difference of thickness can be obtained by the provision of a pair of rolls upstream of the withdrawing rolls.
  • the rolls operative on the seam or joint side will be adjustable perpendicular to the axis of the strand, the amount of adjustment varying during entry of the seam and the effective difference between strand and dummy bar head thickness being rolled away.
  • This difference in thickmess on the seam may alternatively be reduced by blades disposed upstream of the withdrawing rolls.
  • Another solution is to reduce the effective difference between strand and dummy bar head thickness on the seam by flame de-seaming before the seam enters the withdrawing rolls.
  • flame de-seaming may be carried out manually or automatically by a flame de-seaming machine in which latter case, the machine moves in synchronism with the speed of extraction of the strand during the machine operation.
  • the beginning of the strand is produced with an end face differing from the direction of the lines of attack of rolls and the effective difference between strand and dummy bar head thickness is rolled to be wedge-shaped.
  • the strand is produced with an end face differing from the direction of the lines of attack of rolls, for example, with an end face extending at an angle to the strand axis, only part of the beginning of the strand initially comes into the range of operation of the rolls preceding the withdrawing rolls and is rolled away so as to be wedge-shaped. This entry by a partial zone enables control of the adjustment during rolling to be dispensed with.
  • the effective difference between strand and dummy bar head thickness on the seam on entry into the withdrawing rolls is rolled to be wedgeshaped by the contact pressure required for extraction of the strand.
  • the preferable V-shaped end face initially passes ⁇ by just its tip into the withdrawing rolls.
  • the very high specific pressure on this tip as a result of the withdrawing roll contact pressure results in direct wedgeshaped rolling away of this tip so that the next zone of the end face is reliably drawn into the withdrawing rolls.
  • the withdrawing rolls contact pressure is additionally increased by the wedge effect and this reduces any risk of slipping off the withdrawing rolls.
  • the apparatus required for performing the method for producing an end face differing from the direction of the line of attack of the roll is characterised in that the dummy bar head end face facing the beginning of the strand is V-shaped or extends at an angle to the strand axis.
  • FIG. 1 is a diagrammatic view of a continuous casting machine with an arcuate strand guiding system and an additional pair of rolls;
  • FIG. 2 shows the connection between the dummy bar and the strand with a unilateral seam, or joint in accordance with the present invention
  • FIG. 3 shows a dummy bar head with a V-shaped end face according to the present invention.
  • FIG. 4 shows a dummy bar head with an inclined end face according to the present invention.
  • FIG. 1 illustrates a ladle 1, from which the liquid metal flows to a tundish 2. From the latter, the metal is poured into a water-cooled mould 3.
  • the mould 3 is of arcuate shape to form a curved strand.
  • the extraction end of the mould I3 is closed by a dummy bar 4 (FIG. 2) or by the dummy lbar head 5.
  • the cross section of the dummy head 5 is a few millimeters smaller than the cross section of the cavity of the mould 3, as already indicated hereinbefore.
  • the dummy bar 4 extends from the mould 3 to a withdrawing and straightening unit 6, the first pair of withdrawing rolls of which bears the reference 7.
  • the resultant strand 8 with a liquid core is withdrawn from the mould by the dummy bar 4 driven by the unit 6 and is guided in a curved guide having a secondary cooling system 16, in which it is cooled still further.
  • FIG. 3 shows a dummy bar head 5 to an enlarged scale.
  • the dummy bar 4 is in the form of a chain so that it can follow the curved guide 15.
  • I-rails are incorporated in the head 5 and acts as connecting elements between the dummy bar head and the solidified strand and transmit the extracting force from the dummy bar 4 to the cast strand 8.
  • the direction of the end face 21 deviates from the direction of lines of attack of the withdrawing rolls 7 and is shaped to extend in the form of a V in relation to the strand axis.
  • FIG. 4 shows another construction of the end face 22. It again has a direction different from the direction of lines of attack of the withdrawing rolls 7 and extends at an angle to the strand axis.
  • the unit 6 may be preceded by a roll stand 25 with an adjustable top roll. As soon as the seam 9 reaches the zone of the rolls 25, the top roll 25 is adjusted to roll away the effective difference between strand and dummy bar head thickness on the seam 9 by forming a wedge shape so that the strand can be reliably introduced into the following roll stand of the roll 7.
  • the additional roll stand 25 can be eliminated, since the contact pressure of the withdrawing rolls 7, which may be as much as 100 metric tons for large strand cross sections, is sufficient to roll part of the incoming tip of the V-shaped end face of the hot strand to give it a wedge-shape.
  • This rolled zone is suflicient to prevent the strand or its seam 9 from catching on the withdrawing rolls 7 so that the latter slips.
  • the end faces differing from the direction of the lines of attack of the rolls 25 or rolls 7 are in the form of plane surfaces, but the invention covers other shapes. For example, they may be arcuate.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
  • Metal Rolling (AREA)
  • Harvesting Machines For Specific Crops (AREA)
US483525A 1964-08-29 1965-08-30 Method of withdrawing the strand from a continuous casting machine Expired - Lifetime US3372731A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DESC035703 1964-08-29

Publications (1)

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US3372731A true US3372731A (en) 1968-03-12

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US483525A Expired - Lifetime US3372731A (en) 1964-08-29 1965-08-30 Method of withdrawing the strand from a continuous casting machine

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US (1) US3372731A (de)
AT (1) AT249899B (de)
BE (1) BE668456A (de)
DE (1) DE1458214A1 (de)
GB (1) GB1063009A (de)
LU (1) LU49411A1 (de)
SE (1) SE323477B (de)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3521697A (en) * 1967-03-06 1970-07-28 Vitaly Maximovich Niskovskikh Continuous casting starter bar
US3593792A (en) * 1967-06-14 1971-07-20 Schloemann Ag Dummy bar for continuous casting
US3602290A (en) * 1968-08-23 1971-08-31 Mclouth Steel Corp Dummy bar for continuous casting
US3603375A (en) * 1968-12-31 1971-09-07 United States Steel Corp Flexible starter bar for continuous castings
US3645323A (en) * 1969-01-21 1972-02-29 Mannesmann Ag Roll system for continuous casting machines
US3656538A (en) * 1970-12-30 1972-04-18 United States Steel Corp Flexible starter bar
DE2427895A1 (de) * 1973-06-11 1974-12-19 Sumitomo Metal Ind Messanordnung fuer kontinuierlich arbeitende giessmaschinen
US3889740A (en) * 1973-01-12 1975-06-17 Voest Ag Continuous casting plant
US5027889A (en) * 1988-10-10 1991-07-02 Sms Schloemann-Siemag Aktiengesellschaft Dummy bar apparatus and method for steel strip casting

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US379096A (en) * 1888-03-06 Machine for rolling melted metal
US425846A (en) * 1890-04-15 Casting ingots
US494659A (en) * 1893-04-04 Means for manufacturing metal bars or rods
DE674136C (de) * 1935-10-24 1939-04-05 Duerener Metallwerke A G Kokille zum ununterbrochenen Giessen dichter Bloecke
US2176990A (en) * 1937-08-18 1939-10-24 Chase Brass & Copper Co Apparatus for continuously casting metals
US2283368A (en) * 1938-10-14 1942-05-19 Honeywell Regulator Co Automatically reclosing circuit breaker
FR901091A (fr) * 1942-10-23 1945-07-17 Vaw Ver Aluminium Werke Ag Pièce de fond pour la coulée en long de barres de section carrée ou rectangulaire, directement refroidies après leur sortie de la lingotière
GB840676A (en) * 1957-04-10 1960-07-06 John Holroyd & Company Ltd Improvements in or relating to the casting of rods, tubes and the like
US3262161A (en) * 1963-06-27 1966-07-26 United States Steel Corp Sealing and insulating means for continuous casting starter bars
US3966104A (en) * 1975-03-05 1976-06-29 Dayco Corporation Apparatus for severing reinforced elastomeric conduit

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US379096A (en) * 1888-03-06 Machine for rolling melted metal
US425846A (en) * 1890-04-15 Casting ingots
US494659A (en) * 1893-04-04 Means for manufacturing metal bars or rods
DE674136C (de) * 1935-10-24 1939-04-05 Duerener Metallwerke A G Kokille zum ununterbrochenen Giessen dichter Bloecke
US2176990A (en) * 1937-08-18 1939-10-24 Chase Brass & Copper Co Apparatus for continuously casting metals
US2283368A (en) * 1938-10-14 1942-05-19 Honeywell Regulator Co Automatically reclosing circuit breaker
FR901091A (fr) * 1942-10-23 1945-07-17 Vaw Ver Aluminium Werke Ag Pièce de fond pour la coulée en long de barres de section carrée ou rectangulaire, directement refroidies après leur sortie de la lingotière
GB840676A (en) * 1957-04-10 1960-07-06 John Holroyd & Company Ltd Improvements in or relating to the casting of rods, tubes and the like
US3262161A (en) * 1963-06-27 1966-07-26 United States Steel Corp Sealing and insulating means for continuous casting starter bars
US3966104A (en) * 1975-03-05 1976-06-29 Dayco Corporation Apparatus for severing reinforced elastomeric conduit

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3521697A (en) * 1967-03-06 1970-07-28 Vitaly Maximovich Niskovskikh Continuous casting starter bar
US3593792A (en) * 1967-06-14 1971-07-20 Schloemann Ag Dummy bar for continuous casting
US3602290A (en) * 1968-08-23 1971-08-31 Mclouth Steel Corp Dummy bar for continuous casting
US3603375A (en) * 1968-12-31 1971-09-07 United States Steel Corp Flexible starter bar for continuous castings
US3645323A (en) * 1969-01-21 1972-02-29 Mannesmann Ag Roll system for continuous casting machines
US3656538A (en) * 1970-12-30 1972-04-18 United States Steel Corp Flexible starter bar
US3889740A (en) * 1973-01-12 1975-06-17 Voest Ag Continuous casting plant
DE2427895A1 (de) * 1973-06-11 1974-12-19 Sumitomo Metal Ind Messanordnung fuer kontinuierlich arbeitende giessmaschinen
US3937271A (en) * 1973-06-11 1976-02-10 Sumitomo Shipbuilding And Machinery Co. Ltd. Measuring means for measuring secondary cooling zone roller gaps in continuous casting machine
US5027889A (en) * 1988-10-10 1991-07-02 Sms Schloemann-Siemag Aktiengesellschaft Dummy bar apparatus and method for steel strip casting

Also Published As

Publication number Publication date
SE323477B (de) 1970-05-04
BE668456A (de) 1965-12-16
AT249899B (de) 1966-10-10
DE1458214A1 (de) 1970-07-23
GB1063009A (en) 1967-03-22
LU49411A1 (de) 1965-10-27

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