US3795270A - Method of and means for sealing a stopping and withdrawing head in a continuous casting mold for steel - Google Patents

Method of and means for sealing a stopping and withdrawing head in a continuous casting mold for steel Download PDF

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Publication number
US3795270A
US3795270A US00225148A US3795270DA US3795270A US 3795270 A US3795270 A US 3795270A US 00225148 A US00225148 A US 00225148A US 3795270D A US3795270D A US 3795270DA US 3795270 A US3795270 A US 3795270A
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United States
Prior art keywords
seal
sealing
stopping
mold
penetration
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Expired - Lifetime
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US00225148A
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English (en)
Inventor
F Fiala
J Zeller
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SMS Concast AG
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Concast AG
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    • 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
    • B22D11/088—Means for sealing the starter bar head in the moulds

Definitions

  • ABSTRACT A method of and means for sealing -a stopping and withdrawing head in a continuous casting mold for steel, wherein prior to the commencement of pouring the clearance gap between the stopping and withdrawing head and the wall of the mold is sealed with a heat insulating seal that can be introduced into this gap.
  • the steel in contact with the seal in the clearance gap during solidification is stopped from dangerously penetrating the seal by penetration-retarding elements distributed within the cross section of the seal.
  • a known method of preventing the steel from escaping is to cover the clearance gap.
  • the gap and the side of the stopping and withdrawing head facing the steel are covered with metal chips, metal powder or metal granules.
  • These metal chips, powder or granules advantageously should be of the same composition or a similar composition as the cast metal.
  • Another state-of-the-art method of sealing the clearance gap is to insert and ram asbestos into the gap or to introduce refractory materials, preventing direct contact between the asbestos or the refractory material and the molten steel by covering them with chill scrap.
  • effective protection of the seal by chill scrap is a process that is very time-consuming and therefore adversely affects the productivity of such a plant.
  • fusion and sintering of the chill scrap between the hot casting and the stopping and withdrawing head gives rise to the formation of a layer permeated with sharp angular particles which also scratch and score the walls of the mold when the casting is withdrawn.
  • a primary objective of the present invention is to provide just such new and improved method of and means for sealing a stopping and withdrawing head in a continuous casting mold for steel which is not associated with these previously considered drawbacks and limitations of the state-of-the-art and effectively and reliably fulfills the need still prevailing in the art.
  • Another and more specific object of the present invention relates to a new and improved method'of and means for sealing a stopping and withdrawing head in a continuous casting mold in a manner promoting reduction in the time required for making the seal and lessening the idle or downtimes of the casting machine.
  • Yet a further but equally significant object of this invention is to avoid the wear of the mold and the fouling of the casting equipment by loose scrap which occurs when practicing the above-discussed prior art sealing techniques, and further to facilitate the production of seals on stopping and withdrawing heads having hookshaped profiles or the like.
  • the physical hardware used in the practice of such method comprises a seal formed of a sealing material and metal penetration-retarding elements, these metal penetration-retarding elements having at least 50 times the thermal conductivity of the sealing material and about six times its thermal capacity per unit of volume.
  • the seal consists of asbestos cord containing metallic retarding elements. 5 to 50 percent by volume of the seal should consist of retarding elements.
  • the depth of penetration of the steel into the seal can be even further reduced if the heat insulating sealing material completely surrounds the individual retarding elements which are distributed throughout the cross-section of the seal.
  • FIG. I is a vertical sectional view through a partially illustrated mold of a continuous casting plant illustrating the stopping and withdrawing head in its moldinserted position;
  • FIG. 2 is a perspective view showing a pre-formed seal for a stopping and withdrawing head having a hook-shaped profile or section.
  • a stopping and with-' drawing head I also referred to in the art as a dummy bar head, and which has been only partially shown in the drawing, will be seen to close the open bottom end of a continuous casting mold 2.
  • the stopping'and withdrawing head I is separated from the wall 3 of the continuous casting mold 2 by a clearance gap or space 4.
  • a gap 6 In order to form a gap 6 that can be conveniently sealed the upper edge of the stopping and withdrawing .head 1 is provided with a bevel or chamfer 5.
  • the seal 8 is introduced into this gap 6 between the mold wall 3 and the chamfer 5 of the stopping and withdrawing head 1, introduction of such seal being undertaken for instance by ramming same into the gap 6.
  • the seal 8 is formed of asbestos which incorporates an external heat insulating-asbestos layer 11 and metal penetration-retarding elements 10, here in the form of soft steel wires distributed throughout the cross-section of the seal 8 as will be more fully explained hereinafter.
  • the foregoing materials for the seal 8 constitute a particularly useful constructional form of seal, other materials can be efficaciously employed in the practice of the invention as will be also more fully discussed hereinafter.
  • the steel When the steel is poured into the continuous casting mold 2, it begins to solidify, on the one hand, at the neighborhood of the gap at the mold wall 3, and, on the other hand, at the region of the stopping and withdrawing head I.
  • the steel which makes contact with the seal 8 first heats-up the external heat insulating asbestos layer 11 of such sealv 8.
  • the penetration-retarding ele' ments 10 in the case under consideration the soft steel wires, which are present beneath the external asbestos layer 11, dissipate some of the heat penetrating such layer 11 and retard by a number of seconds damage to this layer by fusion, slagging or disintegration.
  • the described chain of events may repeat itself throughout one or a number of further layers.
  • the steel entering the outermost layers of the seal 8 is cooled and solidifies before it is possible for there to occur harmful penetration, i.e. metal breakout through the seal.
  • the steel in the region of the gap above the seal 8 also cools at the mold wall 3 and at the stopping and withdrawing head I.
  • a solidified strandlayer or crust forms a kind of bridge above the seal and continued heating of the seal or even its destruction cannot then result in further deleterious effects.
  • the purpose and functionality of the proposed seal is then fulfilled if its sealing ability is preserved long enough for the bridging crust above it to be sufficiently strong and itself to form a seal from the molten core.
  • sealing materials could also be used, such as glass fibers, slag fibers, refractory felts, refractory plates and the like.
  • penetrationretarding elements could be present in the sealing material in pulverulent or granular form.
  • ceramic retarding elements such as quartz sand, could be incorporated in the seal in place of the metallic elements. Ceramic retarding elements will not fuse, but they can still operate to hinder the penetration of the liquid steel long enough to enable the above-considered bridging to occur in the neighborhood of the sealing gap.
  • the steel wires are completely enclosed at all sides by the asbestos so as to provide an efficacious retarding effect.
  • the gauge of the wire amounts to for instance 0.8 mm. and the center distance between the wires is about 2 mm.
  • the proportion of the seal 8 constituted by the penetration-retarding elements is about 10 percent by volume.
  • the proportion of the seal 8 constituted by the penetration-retarding elements is in a range of about. 5 to 50 percent by volume of the seal.
  • the penetration-retarding elements advantageously I should possess at least 50 times the thermal conductivity of the sealing material and about six times its thermal capacity per unit of volume.
  • FIG. 2 there is illustrated a seal which has been pre-formed according to the shape and periphery of a stopping and withdrawing head 21.
  • a stopping and withdrawing head 21 suchstopping and withdrawing head 21, as indicated in phantom lines, possesses a hook-shaped profile.
  • the preforming of the seal 20 outside of the mold can be undertaken at a pattern corresponding to the shape or configuration of the stopping and withdrawing head 21.
  • the introduction of such seal 20 is also feasible without the expenditure of a great deal of time in those instances where the stopping and withdrawing heads possibly possess undercut zones.
  • a method of sealing a stopping and withdrawing head in a continuous casting mold for metal, especially steel, solely by means of a seal comprising the steps of employing a composite pre-formed heat insulating seal formed of successive alternate regions of a heatinsulating material and a heat-withdrawal material hav ing a greater thermal conductivity than that of the heatinsulating material, sealing the clearance gap between the stopping and withdrawing head and the wall of the mold only by means of the composite pre-formed heat insulating seal having said alternate regions ofsuch materials by introducing the heat insulating seal into the gap prior to commencement of the casting operation, casting metal into the mold, and between the start of the casting operation and the formation of a self sealing metal crust between the mold wall and the stopping and withdrawing head preventing by means of the materials of the seal penetration of metal into the seal to an extent which would be destructive of the seal and its sealing action, and after the formation of the metal crust removing the stopping and withdrawing head together with the composite pre-formed heat insulating seal from the mold so that said pre-formed heat insul

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
US00225148A 1971-02-11 1972-02-10 Method of and means for sealing a stopping and withdrawing head in a continuous casting mold for steel Expired - Lifetime US3795270A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH201771A CH527010A (de) 1971-02-11 1971-02-11 Verfahren und Vorrichtung zum Abdichten eines Anfahrkopfes in einer Stahlstranggiesskokille

Publications (1)

Publication Number Publication Date
US3795270A true US3795270A (en) 1974-03-05

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US00225148A Expired - Lifetime US3795270A (en) 1971-02-11 1972-02-10 Method of and means for sealing a stopping and withdrawing head in a continuous casting mold for steel

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US (1) US3795270A (forum.php)
JP (1) JPS5118226B1 (forum.php)
CA (1) CA955722A (forum.php)
CH (1) CH527010A (forum.php)
GB (1) GB1368653A (forum.php)
IT (1) IT951024B (forum.php)
ZA (1) ZA72873B (forum.php)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4149582A (en) * 1977-07-28 1979-04-17 Concast Incorporated Dummy bar head for continuous casting and method of starting a continuously cast strand
US4178000A (en) * 1977-03-25 1979-12-11 Vereinigte Osterreichische Eisen- Und Stahlwerke - Alpine Montan Aktiengesellschaft Sealing provided between the walls of a cooled continuous mould and the head of a starter bar
US5325910A (en) * 1985-09-20 1994-07-05 Vereinigte Aluminium-Werke Aktiengesellschaft Method and apparatus for continuous casting
US5556109A (en) * 1993-03-30 1996-09-17 Voest-Alpine Industrieanlagenbau Gmbh Method of sealing and seal for a starter bar head to be used in a continuous caster

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS52165067U (forum.php) * 1976-06-07 1977-12-14
JPS5369360U (forum.php) * 1976-11-12 1978-06-10
JPS5386697U (forum.php) * 1976-12-18 1978-07-17
JPS53139974U (forum.php) * 1977-04-13 1978-11-06

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE704512C (de) * 1938-09-20 1941-04-01 Siegfried Junghans Abschluss- und Ausziehvorrichtung beim Giessen von Straengen, insbesondere aus Metal
US2852821A (en) * 1954-12-20 1958-09-23 Olin Mathieson Casting apparatus
US3274653A (en) * 1963-12-26 1966-09-27 United States Steel Corp Quickly disconnectable starter bar
US3525381A (en) * 1967-04-06 1970-08-25 Concast Ag Withdrawal head for continuous-casting moulds and method of using same
US3623534A (en) * 1970-08-19 1971-11-30 American Pipe & Constr Co A method for starting a continuous casting

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE704512C (de) * 1938-09-20 1941-04-01 Siegfried Junghans Abschluss- und Ausziehvorrichtung beim Giessen von Straengen, insbesondere aus Metal
US2852821A (en) * 1954-12-20 1958-09-23 Olin Mathieson Casting apparatus
US3274653A (en) * 1963-12-26 1966-09-27 United States Steel Corp Quickly disconnectable starter bar
US3525381A (en) * 1967-04-06 1970-08-25 Concast Ag Withdrawal head for continuous-casting moulds and method of using same
US3623534A (en) * 1970-08-19 1971-11-30 American Pipe & Constr Co A method for starting a continuous casting

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4178000A (en) * 1977-03-25 1979-12-11 Vereinigte Osterreichische Eisen- Und Stahlwerke - Alpine Montan Aktiengesellschaft Sealing provided between the walls of a cooled continuous mould and the head of a starter bar
US4149582A (en) * 1977-07-28 1979-04-17 Concast Incorporated Dummy bar head for continuous casting and method of starting a continuously cast strand
US5325910A (en) * 1985-09-20 1994-07-05 Vereinigte Aluminium-Werke Aktiengesellschaft Method and apparatus for continuous casting
US5556109A (en) * 1993-03-30 1996-09-17 Voest-Alpine Industrieanlagenbau Gmbh Method of sealing and seal for a starter bar head to be used in a continuous caster

Also Published As

Publication number Publication date
DE2206021A1 (forum.php) 1972-07-27
CA955722A (en) 1974-10-08
GB1368653A (en) 1974-10-02
ZA72873B (en) 1972-10-25
JPS5118226B1 (forum.php) 1976-06-08
IT951024B (it) 1973-06-30
CH527010A (de) 1972-08-31

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