LU86688A1 - Device for casting metal esp. steel, in a pasty phase - in a continuous casting installation - Google Patents

Abstract

Device for casting metal in a plastic phase in a continuous casting mould comprises a vertical pipe arranged ahead of the mould. This vertical pipe is of a truncated section with an angle of inclination of less than 45 deg. and pref. 3-20 deg. to its longitudinal axis and is externally cooled. A distribution component is arranged essentially in the inlet to the vertical pipe in order to deflect the metal flowing from the nozzle of the casting vessel towards the inner surface of the vertical pipe. The vertical pipe may be extended into the mould by a tubular element and consists of an entry section of which at least the inner surface is of a refractory material and the distribution component is arranged in this entry section. It is also provided with some means of blowing a gaseous agent into the vertical pipe, below the distribution component, as well as some means of imparting a rotational motion to the metal in the entry section.

Description

I '- i? ^ "Ö ß ß p ö GRAND-DUCHY OF LUXEMBOURG BL ~ 3974

Patent N "(OJ 0 ÖÖ Minister x of AgsiL of Economy and Average Qasses,. Department of Intellectual Property

Book title -..................................... | LUXEMBOURG

£ C.Ç.% $ • v »Invention Patent Application

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I. Request CENTER DE RESEARCHES METALLURGIQUES-CENTRUM VOOR RESEARCH IN DÇ, METALLURGIEAssociation sans bût lucratlf-VërenigTng fonder winstoogmerk, 47 rue Montoyer, B - 1040 Bruxelies 7 ~ represented by- E; T .Freylinger & E. Meyers y lng. Cons ...... in own. ind., --------------- 46 -rue -dn -Gimefeiëre / Luxembourg ---------------———----- ---------------------- (3) acting - in -quality - of - representatives -------—-------- ----------------------------------------- removal (n ^ ge, uv_ingt-six_novembj ^ jnil ^ eoif- rente.quatre ... twenty .six. (4) at -L5 hours, at the Ministry of the Economy and the Middle Classes, in Luxembourg: "1. the present request for obtaining a invention patent concerning:

Device for casting a metal in the paste phase ^ - (5) 2. the description in French ........................ ........... of the invention in triplicate; 3. two __________________________ drawing boards, in triplicate; 4. the receipt of the taxes paid to the Registration Office in Luxembourg on 2 6 ....... nQ Veiribxe_i3..8.6; 5. the delegation of power, dated ___________________________________ on _____ 6. the successor document (authorization); declaring) assuming responsibility for this declaration, that the inventor (s) is (are): (6)

Mr, ........ Stephan ..... WILMQTTE .., ....... 54., __ rue ...... de ..., 1a ...... Loignerie, B-4930 JJinane -_____

Chaudfontaine ................................................. ......................__........................... .......____________________________ claims (s) for the above patent application the priority of one (s) application (s) of (7) ................ .................................................. .................................................. ........................................_ filed in (8) - ---------------------------------------- the (9) ...... .................................................. .................................................. .................................................. .................................................. ................................._ under N ° (10) ......... .................................................. .................................................. .................................................. .................................................. .......

in the name of (11) ............................................ .................................................. .._............................................... ..................................................

elect (elect) domicile for him / her and, if designated, for his / her representative, in Luxembourg__________________________________________ 46. „rue .du — Cimetière -, - .. Luxembourg ............... .....- --------------------------— - ................ .................... (32) requests (s) the grant of a patent for the invention for the subject described and represented in the abovementioned appendices, with adjournment of this delivery to ......... di.Xr.hui t ............................... ....................... ........................... .............................month. (13) i # cfë /) ûfe # pt / agent: i ................................... ................. · ................................ .................................................___ ........................ __ (14) "Π. Deposit Minutes

The above application for a patent for invention has been filed with the Ministry of the Economy and the Middle Classes,

Intellectual Property Service in Luxembourg, dated: November 26, 1986 nn <= Pr. The Minister of the Economy and the Middle Classes, a — i ---------------- ---- hours fg '; * „Y püd.

; s Ifc: jS n j | / JS g The head of the intellectual property department, | (Ê \ ^ B / I / A 68007 _ / _ / / __ EXPLANATIONS RELATING TO FORMLTVLÎRÛPE DgPCpÇ ^^ "/ Λ / (U if necessary" Request for certificate of additio before revantfiqpàt ^ main patent document No ..................... "- (2) enter the last name, first name, profession, address of the applicant, if this is a paxticufietmtîôcdéSbHnnation, legal form address of the head office when the applicant is a personal— (3) enter BL-3974 ι *, ^

NOT

t Descriptive memory filed in support of a patent application for:

Device for casting a metal in the pasty phase.

METALLURGICAL RESEARCH CENTER CENTRUM VQOR RESEARCH IN DE METALLURGIE Non-profit association Vereniging zonder winstoogmerk 47, rue de Montoyers B - 1040 Brussels% · * C 2377/8611.

METALLURGICAL RESEARCH CENTER -CENTRUM VOOR RESEARCH IN DE METALLURGIE,

Non-profit association -l / ereniging zonder winstoogmerk in BRUXELLES, (Belgium).

Device for casting a metal in the pasty phase.

The present invention relates to a device for casting a metal, particularly steel, in the pasty phase in a continuous casting ingot mold.

The advantage of the pasty phase casting process, that is to say at a temperature within the solidification range of the metal considered, is already known for the continuous casting of metals, such as steel. This process makes it possible to obtain fine structures f

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- 2 - and homogeneous which reduce segregation in the cast products.

The objective of the present invention is to propose a particular device making it possible to create the conditions leading to the appearance of a pasty phase in the metal during its path between the ladle or the tundish on the one hand and the continuous casting ingot mold on the other hand. The casting device according to the invention can therefore be used with a ladle or a casting basket fitted with a conventional nozzle.

To this end, the device for casting a metal in the pasty phase into a continuous casting ingot mold, which is the subject of the present invention, is essentially characterized in that it comprises a vertical duct, arranged upstream of said ingot mold with respect to the direction of circulation of the metal, in that this duct is externally provided with cooling means, and in that a distributing member is disposed substantially at the inlet of said duct, said distributing member being intended to deflect the metal flowing from the nozzle to the interior surface of said vertical duct. '

According to a particular embodiment of the device of the invention, the outlet end of this vertical duct is connected to the inlet end of said mold.

According to another embodiment of the device of the invention, said vertical duct is extended by a tubular element penetrating into the mold.

In this case, the passage section of this tubular element is at least double the outlet section of the nozzle fitted to the ladle or the tundish. This increased section is intended to avoid clogging by the metal which, at this point, is in the pasty phase.

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Also according to the invention, this conduit comprises at least one frustoconical section, converging in the direction of circulation of the metal, the angle a of inclination of the wall of said section not being greater than 60 ° relative to the axis longitudinal of the duct and preferably being between 3 ° and 20 °.

According to another characteristic of the invention, the distributor member is constituted by a substantially horizontal plate; the thickness of said plate decreases from the center towards the edges; it has an external contour such that it provides at least one passage between the edge of the plate and the internal wall of the duct.

Still according to the invention, the casting device further comprises a cap mounted on the inlet end of said conduit and pierced with an opening intended to allow passage to the pouring nozzle. This cap delimits a chamber situated essentially above said distributor member and into which a protective gas can be introduced by appropriate means.

In service, the device of the invention is part of an installation also comprising a ladle or a tundish fitted with a nozzle and a mold for continuous casting. It is mounted between on the one hand the ladle or the tundish and on the other hand the ingot mold, in such a way that said nozzle opens into the inlet end of the vertical duct, above the distributor member, and that the outlet end of the vertical conduit, respectively of the tubular element which extends it, opens into said ingot mold for continuous casting.

The object of the invention will be better understood with the aid of the description which follows of a preferred embodiment of the device of the invention, with reference to the appended drawings in which FIG. 1 represents an elevation view of a device pouring in cross section along line I-Γ in Figure 2; Figure 2 shows a plan view, cap removed, of the casting device of Figure 1; and FIG. 3 illustrates the variant in which the vertical duct is extended by a tubular element penetrating into the ingot mold for continuous casting.

FIG. 1 shows, in elevation, a casting device according to the invention, mounted between a continuous casting mold 1 and a ladle or a casting basket symbolized by the nozzle 2. A tapered copper pipe 3 is mounted on the ingot mold 1; this duct is provided with water cooling shown diagrammatically by the arrows 4 and 5. At the upper end of this duct 3 is arranged a distributor member in the form of a plate 6 whose thickness decreases from the center towards edges. The shape of this plate is adapted to that of the section of the conduit 3. FIG. 2 shows a plate whose edge carries four projections ensuring the centering of the plate in the conduit, while peripheral passages are provided between the projections.

Returning to FIG. 1, the duct 3 is lined with a cap 7 delimiting a chamber 8 above the distributor plate 6. This cap. 7 is provided with an opening in which the nozzle 2 engages; the cap 7 is also provided with a system 9 for introducing a gas under pressure into the chamber 8. Such a gas introduction system is well known per se and is not described in detail here.

FIG. 3 illustrates the variant of the device of the invention, in which the vertical duct 3 is extended by a tubular element 10 penetrating inside the mold 1. If necessary, the lower end of this tubular element 10 can be immersed in the pasty metal that is in the mold. For the rest, this variant corresponds entirely to the representation of FIG. 1.

The mode of operation of this device is as follows.

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The conduit 3 is mounted on the mold 1, then the distributor plate 6 and the cap 7 are in turn put in place. The ladle or the tundish, not shown, is then brought into position so as to engage the nozzle 2 in the opening provided in the cover 7. The nozzle 2 is opened and the superheated liquid steel flows through that -ci on the distributor plate 6. Due to the inclination of the upper surface of the plate 6, the steel flows towards the periphery of the plate 6, then through the passages formed between the centering projections of the plate.

The liquid steel thus flows in a thin layer spreading over the interior wall of the conduit 3. The cooling of the conduit ensures the elimination of the overheating of the steel and causes the appearance of a solid fraction which makes the pasty steel at its entry into the ingot mold 1. The introduction of a pressurized protective gas, for example argon, into the chamber 8 causes an overpressure in this chamber and prevents any entry of air in contact with the liquid steel.

By way of example, blooms of a section of 220 mm × 220 mm, of steel containing 0.7% C, were poured with a flow rate of 20 t / h. The initial superheat of the steel was 25 ° C; the temperature of the steel in the nozzle was 1505 ° C. The steel was poured on a distributor plate made of refractory material, under an argon protection, then along the inner walls of the conduit 3. This was constituted by a frustoconical copper conduit, with a length of 350 mm and with a diameter of 220 mm at mid-length; the angle of inclination a of the wall of the cone cone was 5 ° with respect to the vertical.

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The pipe was cooled by water circulating at high speed ensuring an average density of cooling flow of 3 MW / m2. The evacuated heat flow amounted to 72 MW and led to a solid fraction of 38% by volume in the steel entering the ingot mold.

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The device of the invention has a large heat exchange surface between the cooled pipe and the liquid steel; the high flow speed of the latter along the wall of the duct makes it possible to achieve a high density of heat flow. It would not, moreover, depart from the scope of the invention to increase this density of flux by imparting to the conduit a rotational movement around its axis.

The device of the invention is simple, compact and robust. It has great operational safety, in particular due to a very low risk of blockage.

Claims (7)

1. Device for casting a metal in the pasty phase into a continuous casting mold, characterized in that it comprises a vertical duct disposed upstream of said mold with respect to the direction of flow of said metal, in that the duct is externally provided with cooling means, and in that a distributor member is disposed substantially at the inlet of said duct, said member being intended to deflect the metal flowing from the nozzle towards the interior surface of said vertical duct. 2. Casting device according to claim 1, characterized in that the outlet end of said vertical duct is connected to the inlet end of the mold. 3. Casting device according to claim 1, characterized in that said vertical duct is extended by a tubular element penetrating into the mold. 4. Casting device according to either of claims 1 to 3, characterized in that said duct comprises at least one frustoconical section converging in the direction of circulation of the metal, the angle a of inclination of the wall said section not being greater than 45 ° relative to the longitudinal axis of the conduit, and preferably being between 3 ° and 20 °. 5. A casting device according to any of claims 1 to 4, characterized in that the distributor member is constituted by a substantially horizontal plate, said plate having a thickness decreasing from the center towards the edges and a contour such that 'it spares at least one passage between the edge of the plate and the inner wall of the duct. 6. A casting device according to either of claims 1 to 5, characterized in that it comprises a cap mounted on the inlet end of said conduit and pierced with an opening intended to allow passage to the pouring nozzle. '' 'V - 8 - 7. Installation for the casting of a metal in the pasty phase in a continuous casting ingot mold, characterized in that it comprises a casting device according to either of claims 1 to 6, and in that said device is mounted between on the one hand a ladle or a tundish fitted with a nozzle and on the other hand the continuous casting mold, so that said nozzle opens into the inlet end of the vertical duct, at above the distributing member, and that the outlet end of the vertical duct, respectively of the tubular element which prolongs it, opens into said ingot mold for continuous casting.