EP0049558A2 - Verfahren und Einrichtung zum Bandgiessen - Google Patents

Verfahren und Einrichtung zum Bandgiessen Download PDF

Info

Publication number
EP0049558A2
EP0049558A2 EP81302068A EP81302068A EP0049558A2 EP 0049558 A2 EP0049558 A2 EP 0049558A2 EP 81302068 A EP81302068 A EP 81302068A EP 81302068 A EP81302068 A EP 81302068A EP 0049558 A2 EP0049558 A2 EP 0049558A2
Authority
EP
European Patent Office
Prior art keywords
orifice passage
tundish
molten metal
aperture
cavity
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP81302068A
Other languages
English (en)
French (fr)
Other versions
EP0049558A3 (de
Inventor
Robert Harvey Johns
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Allegheny Ludlum Steel Corp
Original Assignee
Allegheny Ludlum Steel Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Allegheny Ludlum Steel Corp filed Critical Allegheny Ludlum Steel Corp
Publication of EP0049558A2 publication Critical patent/EP0049558A2/de
Publication of EP0049558A3 publication Critical patent/EP0049558A3/de
Withdrawn legal-status Critical Current

Links

Images

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
    • 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
    • B22D11/005—Continuous casting of metals, i.e. casting in indefinite lengths of wire
    • 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

  • Rapid casting of metallic strip material involves delivering a controlled stream of molten metal onto a chilled casting surface.
  • molten metal is poured into a tundish or other receptacle, having a specifically constructed nozzle, or orifice passage, to control the molten metal stream which is delivered onto the casting surface.
  • Such metal may be poured into the tundish from a ladle, directly from a furnace, or the like.
  • Strip casting is a continuous operation; however, it is often necessary or desirable to stop the casting operation quickly.
  • a present method of discontinuing a continuous casting operation is to stop delivering molten metal to the tundish.
  • the metal which is already present in the tundish continues to flow to and through the nozzle and onto the casting surface. It is understandable that the discontinuance of the supply of molten metal to the tundish significantly interrupts an operation which relies upon strict maintenance of steady-state conditions. Therefore, as the molten metal supply is stopped the molten metal stream pressure, and flow patterns to the casting surface are affected resulting in the production of poor quality strip material, scrap material, or perhaps spurts of molten metal until the tundish is nearly empty or until the orifice passage becomes frozen shut.
  • a new and improved method and apparatus for casting metallic strip material is desired which is able to substantially instantaneously stop a strip casting operation when required or desired.
  • Another object of this invention is to provide a strip casting apparatus, which is able to stop molten metal flow to a casting surface as desired and thereby minimize the possibilities and occurences of damage to strip material previously cast. It follows that quickly stopping the metal flow may also reduce possible damage to cast strip material and related equipment.
  • Another object of this invention is to provide a method and apparatus for diverting molten metal from a strip casting tundish after a casting operation is completed to allow such tundish to be reused in subsequent casting operations.
  • the present invention provides strip casting apparatus comprising a tundish having an internal cavity for receiving and holding molten metal, and an orifice passage defined between two spaced lips in the tundish through which molten metal is delivered to a casting surface located within 3.048mm (0.120 inch) of the orifice passage, and movable past the orifice passage at a speed of from 61 to 3048 metres (200 to 10,000 linear surface feet) per minute, characterized in that:-
  • the present invention also provides a method for substantially instantaneously stopping a strip casting operation comprising the step of:
  • the apparatus includes a tundish generally designated by reference numeral 10.
  • the tundish 10 necessarily has an internal cavity 12 designed to receive and hold molten metal.
  • the tundish lO further includes an orifice passage or nozzle 14, through which the molten metal in the cavity is delivered to a casting surface 16.
  • molten metal is delivered from the nozzle 14 onto the outer peripheral surface 16 of a water cooled precipitation hardened copper alloy wheel containing about 99% copper.
  • Copper and copper alloys are chosen for their high thermal conductivity and wear resistance although other materials may be utilized for the casting surface 16.
  • the casting surface 16 is movable past the nozzle 14 at a speed of from 61 to 3048 metres (200.to about 10,000 linear surface feet) per minute.
  • the tundish lO may be comprised of at least one upper block 20, at least one lower block 30, _ and, perhaps, intermediate blocks 22.
  • the terms upper and lower, as well as the terms front and rear are used with general respect and reference to the casting surface 16 with the terms upper and rear referring to locations away from the casting surface 16.
  • the term vertical is used herein with general respect and reference to the force of gravity.
  • the upper and lower blocks 20 and 30 of the tundish 10 illustrated in Figure 1 are preferably vertically aligned and secured together. Such vertical alignment is explained in our co-filed patent application entitled Strip Casting Apparatus.
  • the secured blocks should allow molten metal in the cavity 12 to pass through any interface of the assembly. It should be understood that in instances where the orifice passage 14 is located at an interface, as shown in Figure 1, molten metal is intended to pass therethrough.
  • a tundish of the apparatus of the present invention may . consist of horizontally aligned blocks, or may be a monolithic structure.
  • tundish materials utilized in the apparatus of the present invention must be resistant to molten metal attack.
  • refractory boards such as insulating boards made from fiberized kaolin are suitable.
  • Additional materials including graphite, alumina graphite, fire clay, clay graphite, quartz, boron nitride, silicon nitride, silicon carbide, boron carbide, alumina, silica, zirconia, stabilized zirconium silicate, magnesia, chrome magnesite, and combinations of such materials. may also be used to construct such blocks.
  • such tundish 10 is constructed of vertically aligned or horizontally stacked sections of 38mm (1.5 inch) thick Kaowool fiberboard. It should be noted that thicker or thinner blocks may be employed depending upon the desirable strip casting conditions. The 38mm (1.5 inch) thick blocks are utilized in this preferred embodiment because of their commercial availability.
  • the tundish 10 includes a cavity 12 consisting of at least one introductory cavity portion 32.
  • the introductory cavity portion 32 preferably extends from an upper surface of the tundish 10 through an upper portion of the tundish 10 and is in communication with a base cavity portion 34 formed in a hollow section at -a lower portion of the tundish 10.
  • the opening for the introductory cavity portion 32 is preferably located in the upper surface of the tundish 10 as shown in the drawings. However, such opening may be disposed elsewhere such as in a sidewall of the tundish 10. Also, as shown in the drawings, it is preferred that the opening be slightly radiused into a funnel shaped structure to facilitate metal transfer therethrough.
  • the formation of the base cavity portion 34 and the orifice passage 14 are critical in the apparatus of the present invention.
  • the base cavity portion 34 is typically carved or cast in a bottom portion of the tundish and may be formed between a bottom surface 36 of an intermediate block 22 and the carved surface 38 of a bottom block 30 of a vertically stacked tundish 10, as shown in Figure 1.
  • At least a portion, and perhaps the majority of the bottom surface 38 of the base cavity 34 is disposed below the height of the orifice passage 14.
  • at least a portion of the bottom surface 38 of the base cavity 34 is disposed at least 6.35mm (0.25 inch) below the height of the orifice passage 14.
  • the bottom surface 38 of the base cavity 34 extend upwardly toward the orifice passage 14 at an angle of at least 30° from horizontal.
  • the orifice passage 14 through which molten.metal is fed onto the casting surface 16 preferably has a substantially uniform width dimension throughout the longitudinal extent thereof.
  • Such width dimension is at least 0.254mm (0.010 inch) and preferably less than 3.048mm (.120 inch). More preferably, such width dimension for the orifice passage 14 i's within the range of from 0.508 to 1.524mm (0.020 to 0.060 inch), and even more preferably from 0.762 to 1.27mm (0.030 to 0.050 inch).
  • the orifice passage 14 may be constructed in a number of ways in the apparatus of the present invention.
  • the orifice passage 14 is formed between the bottom surface 36 of an intermediate block 22, and a cut-out portion extending across a front wall of the bottom block 30.
  • a molten metal resistent plate 40 be disposed in such intermediate block 22.
  • At least one surface forming the orifice passage 14 comprises the surface of the plate 4 0 .
  • the upper surface of the --- ; orifice passage 14 comprise a surface of the plate 40 of molten metal resistant material. It should be understood that it is more critical to maintain the upper surface of the orifice passage during casting and, therefore, it is preferable to use a plate 40 at such location.
  • the bottom surface or alternatively both surfaces of the orifice passage 14 may consist of a surface of a plate 40.
  • the plate 40 should be at least as resistant to the molten metal as are the blocks, and preferably, the plate is significantly more molten metal resistant than the blocks forming the remainder of the tundish 10.
  • the plate 40 may be fitted into an appropriate slot cut in the bottom surface 36 of an intermediate block 22.
  • the plate 40 should have a length greater than the longitundinal extent of the orifice passage 14.
  • the peripheral end portions of the plate 40 are sandwiched between adjacent blocks 22 and 30 in the assembly illustrated in Figure 1.
  • Such structure is further illustrated in our said cofiled patent application mentioned above.
  • the plate 40 is formed of boron nitride.
  • boron nitride other materials including silicon nitride, silicon carbide, boron carbide, silica, alumina, zirconia, stabilized zirconium silicate, graphite, alumina graphite, fire clay, clay graphite, quartz, magnesite, chrome magnesite and combinations of such materials may be used for constructing the plate 40.
  • the introductory cavity portion 32 is in communication with the base cavity portion 34.
  • the introductory cavity portion 32 comprises a tubular passageway through the tundish 10.
  • the total height of the tubular passageway should be that which is necessary to provide the cavity height required to control and contain the desired metallostatic head pressure at the orifice passage 14 of the tundish 10. It has been found that maintaining a substantially constant molten metal level about 50.8mm (two inches) above any orifice passage provides a metallostatic head pressure of about 35 grams per square centimetre (0.5 psi) which is typically adequate for casting strip material.
  • Means may also be provided to heat the plates 40 forming one or both lips of the orifice passage 14.
  • at least one lance is disposed in the tundish with the tip thereof directed toward the plate 40.
  • a corresponding aperture may be provided in such tundish through which the combustion products which are delivered against the plate 40 from such lance may escape the tundish.
  • the temperature of the plates 40 can be raised to the desired level prior to the initiation of a strip casting operation. It has been found that heating such plates near the melting temperature of the alloy to be cast prevents metal from freezing in such cavity which may otherwise occur especially at the initiation of a casting operation.
  • high temperature flames from reactive gases are directed through a plurality of lances towards the plate 40.
  • a more flame resistant heat conductive layer may be provided on at least a portion of the upper surface of the plate 40 at least at the location where such flames impinge against the plate 40.
  • Such layer serves to absorb flame abuse and still to transfer the heat to the plate 40 therebelow.
  • such layer is graphite, although other materials may be employed.
  • Such heating lance structure is described in our co-filed patent application entitled Strip Casting Apparatus With Heated Orifice.
  • At least one aperture 60 is provided through a lower portion of the tundish lO.
  • such aperture is in communication with a portion of the base cavity 34 which is preferably located vertically below the height of the orifice passage 14.
  • a plug 62 disposed in the aperture 60.
  • plug is meant to encompass gates, flaps, stopper rods or any other molten metal restricting apparatus which can be opened as desired.
  • the purpose of the aperture 60 and the corresponding plug 62 is to provide a drain through which molten metal in the tundish can be directed to substantially instantaneously stop molten metal from being delivered through the orifice passage 14 when it is desired or required to stop a casting operation.
  • the casting operation should be stopped within one second, and preferably within about one- half second, in order to minimize adverse affects that could result if the orifice 14 continued to deliver molten metal to a casting surface 16 in an uncontrolled fashion.
  • the term substantially instantaneously means at least within one second.
  • the size of the aperture 60 must be at least large enough to divert sufficient molten metal in the internal cavity through the aperture when the plug is removed. Such diverted molten metal flow must further have the effect of reducing the metallostatic head pressure at the orifice passage below that pressure necessary to cast strip material.
  • the orifice passage 14 is located vertically above, with respect to the direction of pressure in the tundish 10', at least a portion of the base cavity 34.
  • the internal cavity is disposed at least 6.35mm (0.25 inch) below the orifice passage 14.
  • the direction of pressure is usually the direction of gravitational force.
  • the tundish 10 may be disposed at any location about the casting surface 16 and casting pressure may be obtained by auxiliary devices.
  • the size of the aperture, or apertures, for diverting molten metal flow from the tundish should depend upon the various strip casting parameters that are being employed. Functionally, the size of the aperture should be that which is sufficient to effect a reduction in the metallostatic head pressure at the nozzle 14 below that pressure necessary to cast strip material.
  • the aperture should be large enough to cause the metallostatic head pressure at the orifice passage 14 to drop below 35g/cm 2 (0.5 psi.).
  • the molten metal in the cavity 12 be drained from the tundish 10 at the end of a casting operation.
  • the tundish is readily reusable in subsequent casting operations with little or no cleaning or machining.
  • the internal geometry of the casting cavity may be of importance with respect to the final quality of the metallic strip material produced thereby. Such geometry factors seem to be significantly more important as the width of the cast strip material increases. It has been found that for a given set of conditions of melting temperature, metallostatic head height, orifice opening, plate 40 temperature, casting surface speed and orifice to casting surface distance, minor changes in the casting cavity design may produce significant variations in across width quality of wider metallic strip material if certain geometric preferred design features are not employed. These preferred features include two specific areas; cavity slope, and cross cavity profile. In a preferred embodiment the bottom surface 38 of the base cavity 34 extends upwardly toward the orifice passage 14 at an angle of at least 30 from horizontal.
  • the cross profile of the bottom surface 38 of the base cavity 34 should have a dish type configuration.
  • the height of the base cavity at a central portion is preferably at least 2.54mm (0.10 inch) greater than the height of the base cavity 34 as measured at both lateral edges of the base cavity 34.
  • the introductory cavity 32 in a tundish of the present invention may be provided by drilling one or more appropriately sized holes through the tundish material.
  • the bottom portion of the tundish may be appropriately shaped into an outwardly extending'fan shaped structure diverging outwardly from the bottom of the tubular introductory cavity 32, in the direction of the orifice passage 14 approximately to the width of the strip to be cast.
  • the alternative of drilling a plurality of holes into the tundish to provide the introductory cavity 32 usually depends upon the width of the strip material to be cast, and thus the width of the orifice passage 14.
  • the orifice passage 14 should have a substantially uniform width dimension throughout the longitudinal extent thereof. Such width dimension may be slightly altered at the lateral edges of the orifice passage.
  • the edge quality of the metallic strip material produced by the apparatus of the present invention may be improved by fanning out the lateral edge portions of the orifice passage.
  • the height to which such lateral edge portions may be fanned should not exceed 1.5 times the uniform width of the orifice passage 14.
  • the length at the lateral end portions of the orifice passage 14 which can be fanned should not exceed twice the uniform width of the orifice passage 14.
  • What is critical about such fanning structure is that slightly more molten metal be made available at the lateral edge portions than is available along the internal portions of the orifice passage. Such fanning must continuously increase the orifice passage 14 height dimension in the direction of the lateral edge of the orifice passage 14 and such height dimension must not decrease in such lateral direction.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)
  • Dental Preparations (AREA)
  • Fats And Perfumes (AREA)
  • Medicinal Preparation (AREA)
EP81302068A 1980-10-06 1981-05-08 Verfahren und Einrichtung zum Bandgiessen Withdrawn EP0049558A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US19398280A 1980-10-06 1980-10-06
US193982 1998-11-18

Publications (2)

Publication Number Publication Date
EP0049558A2 true EP0049558A2 (de) 1982-04-14
EP0049558A3 EP0049558A3 (de) 1982-05-12

Family

ID=22715852

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81302068A Withdrawn EP0049558A3 (de) 1980-10-06 1981-05-08 Verfahren und Einrichtung zum Bandgiessen

Country Status (14)

Country Link
EP (1) EP0049558A3 (de)
JP (1) JPS5764454A (de)
KR (1) KR850000921B1 (de)
AT (1) ATA205581A (de)
AU (1) AU6997181A (de)
BR (1) BR8102822A (de)
CA (1) CA1194270A (de)
ES (1) ES502056A0 (de)
HU (1) HU183420B (de)
MX (1) MX154958A (de)
NO (1) NO161041C (de)
PL (1) PL231041A1 (de)
RO (1) RO84261B (de)
YU (1) YU96781A (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101140746B1 (ko) * 2004-09-30 2012-05-15 코닌클리즈케 필립스 일렉트로닉스 엔.브이. 밀봉 호일을 갖는 전기 램프

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2091851B1 (de) * 1969-12-26 1973-05-25 Namy Philippe
JPS537411U (de) * 1976-07-02 1978-01-23
AU503857B2 (en) * 1976-10-22 1979-09-20 Allied Chemical Corp. Continuous casting of metal strip
JPS5938062B2 (ja) * 1978-03-15 1984-09-13 日本碍子株式会社 金属の連続鋳造法
US4221257A (en) * 1978-10-10 1980-09-09 Allied Chemical Corporation Continuous casting method for metallic amorphous strips

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101140746B1 (ko) * 2004-09-30 2012-05-15 코닌클리즈케 필립스 일렉트로닉스 엔.브이. 밀봉 호일을 갖는 전기 램프

Also Published As

Publication number Publication date
HU183420B (en) 1984-05-28
RO84261A (ro) 1984-05-23
YU96781A (en) 1983-12-31
EP0049558A3 (de) 1982-05-12
ES8301713A1 (es) 1983-01-01
KR850000921B1 (ko) 1985-06-28
JPH0448542B2 (de) 1992-08-07
CA1194270A (en) 1985-10-01
RO84261B (ro) 1984-07-30
ATA205581A (de) 1986-06-15
NO161041C (no) 1989-06-28
NO811583L (no) 1982-04-07
BR8102822A (pt) 1982-08-24
MX154958A (es) 1988-01-14
PL231041A1 (en) 1982-04-13
JPS5764454A (en) 1982-04-19
AU6997181A (en) 1982-04-22
NO161041B (no) 1989-03-20
ES502056A0 (es) 1983-01-01
KR830005934A (ko) 1983-09-14

Similar Documents

Publication Publication Date Title
CA2082459C (en) Impact pad for a continuous caster tundish
US6070647A (en) Casting metal strip
US5857514A (en) Strip casting
US6003589A (en) Strip casting apparatus
US6012508A (en) Strip casting
EP0049937B1 (de) Vorrichtung und Verfahren zum Giessen von Bändern
US6125917A (en) Strip casting apparatus
EP0049558A2 (de) Verfahren und Einrichtung zum Bandgiessen
EP0859675B1 (de) Verfahren und vorrichtung zum giessen eines metallbandes
US3446267A (en) Continuous casting mold
EP0049556A1 (de) Vorrichtung zum Giessen von Bändern mit beheizter Giessdüse
EP0049557A1 (de) Vorrichtung zum Giessen von Bändern mit beheizter Giessdüse
US4488590A (en) Apparatus for strip casting having a heated orifice
EP0040070B1 (de) Vorrichtung zum Giessen eines Streifens
AU731277B2 (en) Strip casting
AU732559B2 (en) Casting metal strip
JPH01293943A (ja) 双ロール式連鋳機
JPS6440149A (en) Pouring method in twin belt type continuous casting equipment
JPH10211553A (ja) 金属ストリップ鋳造方法及び装置並びに双ロールストリップ鋳造装置の鋳造溜めへ溶融金属を供給する耐火ノズル

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Designated state(s): BE DE FR GB IT SE

AK Designated contracting states

Designated state(s): BE DE FR GB IT SE

17P Request for examination filed

Effective date: 19820827

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 19841124

RIN1 Information on inventor provided before grant (corrected)

Inventor name: JOHNS, ROBERT HARVEY