AU604354B2

AU604354B2 - Dual roll type continuous casting machine

Info

Publication number: AU604354B2
Application number: AU22491/88A
Authority: AU
Inventors: Hisahiko Fukase; Atsushi Hirata; Kunio Matsui; Akihiro Nomura
Original assignee: IHI Corp
Current assignee: IHI Corp
Priority date: 1987-09-22
Filing date: 1988-09-21
Publication date: 1990-12-13
Anticipated expiration: 2008-09-21
Also published as: DE3832003A1; KR890004793A; JPS6483338A; AU2249188A; DE3832003C2; CN1032505A

Description

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AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application number: Lodged: Complete Specification Lodged: Accepted: Publisned: Priority 0 0oa ~This do=ument containlls h Related Art: amendments made under Section 49 and is correct for printing.

00o 1 APPLICANT'S REFERENE: 676 Name(s) of Applicant(s): 0 Ishikawajima-Harima Jukogyo Kabushiki Kaisha a Address(es) of Applicant(s): No. 2-1. 2-chome, Ote-Machi, Chiyoda-ku, Tokyo-to,

JAPAN.

Address for Service is: A PHILLIPS ORWONDE FIT ZPARICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Complete Specification for the invention entitled: UAL ROLL TYPE CONTINUOUS CASTING MCHINE Our Ref 105171 POP Code: 1592/39433 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 6003q/1 *1

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DUAL ROLL TYPE CONTINUOUS CASTING MACHINE BACKGROUND OF THE INVENTION The present invention relates to a dual roll type continuous casting machine for continuously casting a metal strip.

In a conventional dual roll type continuous casting machine as shown in Fig. 1, melt 4 is supplied to an upper surface defined by a pair of cooling rolls 2 and 3 which are arranged horizontally and in parallel with each other and which have side weirs 1 disposed on both sides of the rolls 2 and 3, thereby forming a basin. Melt 4 is cooled by the cooling rolls 2 and 3 which are rotating and a casting 5 is withdrawn through the gap between the rolls 2 and 3.

r In order to supply melt 4, melt 4 is made to flow through S* cylindrical nozzles 8 communicated with pouring holes 7 formed through the bottom of a tundish 6 in the direction of the width thereof so that the flow of melt 4 in the basin becomes nonuniform or the surface of the basin is disturbed, resulting in fine or minute variations of the 4. 4 static pressure of melt. As a result, the casting cannot be carried out under stabilized conditicns. Furthermore when melt flows down through the cylindrical nozzles 8 onto the basin, the oxidized film over the surface of the latter is entrained by melt 4 and is mixed into *t he casting 5 so that the quality of the casting 5 is degraded.

In order to overcome the above-described problems, there has been proposed a continuous casting machine in which, as shown in Figs.

2 and 3, a core 9 having the width substantially equal to that of *s casting 5 is securely joined to the bottom of the tundish 6 sue'. ,hat passages 10 defined in the core 9 are communicated with the p',r'ing holes 7 and outlets of the passages 10 at the bottom of th/, <.ore 9 are immersed into the basin.

However, when the continuous casting is carried out while the bottom portion of the core 9 is immersed in the basin as described above and when the core 9 is made of a hard fire-resisting material with a high degree of thermal conductivity, heat of melt 4 in the basin in contact with the bottom of the core 9 (especially heat in the vicinity of the surface of the basin) is absorbed by the core 9 so that as time advanced the solidified shell grows from the bottom of the core. It is therefore experimentally confirmed that the core 9 must be preheated.

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In view of the above, there has been proposed and demonstritced to use a porous fire-resisting material such as fiber board to fabricate the core 9 so that the core has a high degree of heat insulation, whereby the absorption if heat from melt 4 in the basin can be prevented and the growth of the solidified shell from the bottom of the core 9 can be avoided without preheating of the core 9.

However, when the whole structure of the core 9 is made of a porous heat-resisting material, portions of the core 9 defining the passages 10 tend to be melted because of high-temperature melt 4 always flowing from the tundish 6 therethrough so that there arises the problem that the shapes of the passages 10 are deformed.

In view of the above, a pr.mary object of the present invention *e S° is to provide a dual r?11 type continuous casting machine in which .o melt-down of the passage-defining portions in a core can be prevented 15 and the growth of the solidified shell from the uottom of the core can o be avoided.

o W4-h-li-s-In-f-i-Rdthe r-oesent-i- we-n-t-io.n .p.ro-i-desa-a- r type continuous casting machine comprising a tundish w.th paurin holes formed through a bottom thereof, said tundish being di osed 20 above a basin which is defined by a pair of cooling roll and side weirs on both ends thereof, a core securely joi.ed t the bottom of said tundish such that passages defined in said tore are communicated with said pouring holes and outlets of said passages are immersed into said basin, at least portions of said core defining said passages being made of a hard, fire-resisting material, and at least portions of said II core in contact with melt in said basin except said passage-defining portions being made of a porous, fire-resisting material, The above and aoher objects and features of the present invention will become more apparent from the following description of a preferred emnb-ddiments thereof taken in conjunction with the accompanyi drawings, BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view used to explain a conventional continuous SA a t ig-nmah4i -2-

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According to the present invention there is provided a dual roll type continuous casting machine comprising a tundish with pouring holes formed through a bottom thereof said tundish being disposed above a basin which is defined by a pair of cooling rolls and a respective side weir at each end of said basin; and a core securely joined to the bottom of said tundish such that passages defined in said core communicate with said pouring holes, and outlets of said passages are located within said basin; internal portions of said core being made of a hard, fire-resisting material, and at least external portions of said core within said basin, and contactable with melt therein, being made of a porous, fire-resisting material.

The above and other objects and features of the present invention will become more apparent from the #oo O following description of a preferred embodiments thereof "taken in conjunction with the accompanying drawings.

0 BRIEF DESCRIPTION OF THE DRAWINGS 06 0 Fig. 1 is a view used to explain a conventional o0 0 20 continuous casting machine; 0 0 00 9o00 oo -2a- -c Fig. 2 is a view used to explain a dual roll type continuous casting machined which has been developed recently; Fig. 3 is a sectional view taken along the line III-III of Fig. 2; and Fig. 4 is a sectional view (corresponding to Fig. 3 prior art) of a preferred embodiment of the present invention.

DETAILED DESCRIPTON OF THE PREFERRED EMBODIMENT In Figs. 3 and 4, same reference numerals are u:ed to designate similar parts.

Referring to Fig. 4, the portions defining passages 10 of the core 9 which are directly exposed to high-temperature melt 4 flowing 0 *qooo down from the tundish 6 are made of a hard, fire-resisting material 9a such as alumina. Except these, the core 9 is made of e, porous fireo resisting material 9b such as fiber board.

SWith the above-described construction, high-temperature melt S 15 4 in the tundish 6 flows _hrough the pouring holes 7 and the passages 0 10 made of a hard, fire-resisting material 9a into the basin defined by the cooling rolls 2 and 3 so that the passages 10 are prevented from So being melted and distorted in shape.

Melt 4 supplied to the basin contacts he bottom of the core 20 9 made of the porous fire-resisting material 9b so that absorption of oeo. heat by the core 9 in contact with melt 4 can be substantially prevented. Growth of the solidified shell from the bottom of the core 9 can be prevented without preheating of the core 9.

It is to be understood that the present invention is not limited to the above-described embodiment and that various S* "modifications may be made within the true spirit of the present invention. For instance, only the surfaces of the core 9 in contact with melt 4 may be made of the porous, fire-resisting material 9b, the other portion of the cure 9 being made of the hard, fire-resisting material 9a.

As is clear from the above, the present invention can attain the excellent features that the melt-down of the passage-defining portions of the core through which high-temperature metal from the tundish flows can be prevented and that the growth of the solidified shell from the bottom of the core can be avoided without preheating of the core.

Claims

1. A dual roll type continuous casting machine comprising a tuudish with pouring holes formed through a bottom thereof said tundish being disposed ibove a basin which is defined by a pair of cooling rolls and a respective side weir at each end of said basin; and a core securely joined to the bottom of said tundish such that passages defined in said core communicate with said pouring holes, and outlets of said passages are located within said basin; internal portions of said core being made of a hard, fire-resisting material, and at least external portions of said core within said basin, and contactable with melt therein, being made of a porous, fire-resisting material.

2. The machine according to claim 1, wherein said hard, J c fire-resisting material is alumina.

3. The machine according to claim 1 or 2, wherein said porous, fire-resisting material is fibre board.

4. A dual roll type continuous casting machine substantially as herein before described with reference to what is shown in Figure 4 of the anc-ompanying drawings. DATED: 3 SEPTEMBER, 1990 PHILLIPS ORMONDE FITZPATRIC 4 Attorneys For: ISHIKAWAJIMA-HARIMA JUKOGYO KABUSHIKI KAISHA 1826Z 39 -4- 4C NT K A