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
  • 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
• • 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
  • B22D11/0648—Casting surfaces
  • B22D11/066—Side dams
• • 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
  • B22D11/0622—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by two casting wheels

Definitions

• the invention relates to the continuous casting of metals. It relates more particularly to installations for continuous casting of thin metallic strips of the type called "casting between cylinders".
• the casting of thin metal strips a few mm thick directly from liquid metal can take place on a so-called "casting between cylinders" installation, supplied with metal liquid from a distributor, by means of a pouring nozzle.
• the machine comprises an ingot mold, the casting space of which is delimited on its long sides by a pair of internally cooled cylinders with parallel horizontal axes and rotating around these axes in opposite directions, and on its short sides by closure plates made of material. refractory, called “side faces”, which are applied by thrust members against the flat ends of the cylinders.
• a support plate preferably made of a material with strong insulating properties, such as silica. Most often, it is fixed on its rear face (that facing outwards from the casting space) to a metal plate on which the thrust members act. However, if the support plate has sufficient mechanical strength and rigidity, provision can be made for the thrust members to exert their action directly on the support plate.
• On the front face of this support plate there is the active part of the lateral face, that is to say the material or materials which are intended to come into contact with the cylinders and the liquid metal.
• the external zones of this active part which must come into contact with the cylinders or be in the vicinity of the neck, are made of a first material for which the qualities of resistance to abrasion and to corrosion by the liquid metal, such as SiAlON * or silicon carbide, and the central zone of this active part, which must be in contact with the liquid metal, is made of a second material for which the insulating properties are preferred, such as foam silica.
• the element or elements making up the external zones are often designated by the term "Insert", and the element or elements forming the remainder of the lateral face by the term "heart".
• the lateral faces are of fundamental importance in the success of a casting of metal strips between cylinders, in particular of steel strips. Poor sealing of their contacts with the edges of the cylinders can lead to liquid metal exfiltration out of the casting space, which compromises the regularity of the operation of the installation, therefore the quality of the strip. In extreme cases, these exfiltrations can lead to stopping the casting. Similarly, a rupture during casting of one of its elements, or a decohesion of the multiple elements composing the active face, lead to stop the casting without delay.
• the lateral faces constitute one of the main elements of the operating cost of an installation for casting thin strips between cylinders (or, in general, between two walls cooled in movement), and any technical advance which would allow it is highly desirable to reduce the time and material expenses associated with them, without affecting their performance and reliability.
• the object of the invention is to propose a design of the lateral faces of an installation for casting thin metal strips between two walls which are cooled in movement, the cost of manufacture and use of which is considerably lowered compared with the lateral faces of conventional design. .
• the subject of the invention is a lateral face for closing off the casting space of a continuous casting installation for thin metal strips between two walls cooled in movement, in particular of "casting between cylinders" or of “ casting between strips ", of the type comprising a support plate, on the rear face of which pushing members exert their action in order to apply said lateral face to the edges of said cooled walls, optionally by means of a metal plate integral with the rear face of the support plate, and an active face disposed against the front face of the support plate, the lateral portions of which are intended to wear out in contact with said sections of said walls cooled to a maximum depth "e” and a width "1", the support plate and the active part being brought into contact with one another in a manner allowing their separation in a non-destructive manner , characterized in that the front face of the support plate has in its central part a recess whose depth is greater than "e”, and in that the external edges of said front face have a general shape which matches that of the external edges of the part active
• the invention consists in designing the lateral face so as to allow the use of its active part for no longer just one, but two flows, by simply turning this active part between the two flows .
• a particular shape must in particular be given to the front face of the support plate. This results in considerable savings on the preparation time of the side face before the second casting in the series.
• FIG. 1 which shows front view (Figure 1 a) and top view in section along Ib-Ib a side face of casting thin strips according to the prior art in its initial state ( Figure lb), and top view in section according to Ib-Ib after its use (figure le);
• FIG. 2 which shows a top view in section according to Ib-Ib a first example of a lateral face for casting thin strips according to the invention in its initial state, before its first use ( Figure 2a) and before its second use ( Figure 2b);
• FIG. 3 which shows a top view in section according to Ib-Ib a second example of a lateral face for casting thin strips according to the invention in its initial state, before its first use;
• FIG. 4 which shows a top view in section according to Ib-Ib a third example of a lateral face for casting thin strips according to the invention in its initial state, before its first use
• - Figure 5 which shows a top view in section according to Ib-Ib a fourth example of a lateral face for casting thin strips according to the invention in its initial state, before its first use.
• the various elements of the side faces have not been shown to scale in the figures.
• the casting rolls have a diameter of the order of 500 to 1500 mm, and the neck has a width of a few mm, corresponding to the thickness of the strips which it is desired to cast.
• the sample side surface 1 according to the prior art, shown schematically in Figure 1 comprises the following elements: - a support plate 2 made of refractory material with high insulating properties, integral on its rear face 3 a metal plate 4 cooled, on which thrust members (not shown) exert their action in the direction indicated by the arrows 5, so as to apply the side face 1 against the edges of the casting rolls; the contours 6, 6 'of said cylinders are drawn in dotted lines, and the level of the neck 7 is indicated by a line xx in broken lines;
• an active part disposed on the flat front face 8 of the support plate 2, and which is composed of two elements, namely a core 9 made of a refractory material, the insulating properties of which are preferred (such as silica foam), and an insert 10 of a refractory material which are preferred resistance properties to wear by friction and corrosion by the liquid metal (such as ® SiAlON, silicon carbide);
• the insert 10 is formed by a single piece, but it can also be formed by the juxtaposition of several pieces; the heart 9 and the insert 10 are secured to one another, for example by gluing, and the whole of the active part which they constitute is enclosed in a belt 11, preferably metallic, which strengthens its cohesion .
• the support plate 2 and the active core 9-insert 10 part are held one against the other, preferably by means making it possible to separate them after casting without destroying them or, at least, without damaging the support plate 2, so that the latter can be reused after said casting.
• Bolting, or a cradle integral with the support plate 2 or integrated into it and into which the active part is inserted, are examples of such means.
• the side face 1 After having been used during a single casting, the side face 1 is in the state shown in FIG.
• the portions of the insert 10 which rubbed against the cylinders were eroded to a depth "e" which can be of the order of several mm, or even a few cm (typically, approximately 10 mm), depending on the duration of the casting, the nature of the material of the insert 10 and the extent of the friction to which it has been subjected.
• the core 9 has been hollowed out under the effect of corrosion by the liquid metal, and also under the effect of friction with the liquid metal in motion inside the casting space 12.
• the active part is often covered, at least in places, with a layer of solidified metal 13 which is deposited there at the end of casting.
• FIG. 2 when viewed from the front, has the same appearance as the lateral face according to the prior art 1 shown in front view in FIG. This will also be the case for the other examples of lateral face according to the invention which will be described below, except for the fourth example shown in FIG. 5). We will therefore not present a specific front view for the examples of lateral face according to the invention.
• the elements common with the lateral face 1 according to the prior art are designated by the same references.
• the front face 16 of the support plate 15 is not flat: it has in its central part, over its entire height, a recess 17 whose shape and function will be explained below.
• the active part of this lateral face 14 also has a particular configuration. It comprises a central plate 18 made of an insulating refractory with a low coefficient of expansion (based on silica, for example), having on its two faces recesses 19, 20. In each of these recesses 19, 20, a formed assembly is housed. a heart 21, 21 'and an insert 22, 22', the constitutions and dimensions (with the possible exception of the thickness) are identical to those of the heart 10 and the insert 9 of the face lateral 1 according to the prior art previously described. The two core-insert assemblies 21-22, 2T-22 'are secured to the central plate 18 by means of an adhesive allowing relative movements of the bonded parts sufficient to absorb the differential expansions due to the different natures of the materials involved.
• An example of such an adhesive consists of the product marketed under the name "REFRACOL No. 4", which is a refractory jointing cement based on corundum, comprising a binder based on sodium silicate. This binder makes the glue vitreous at high temperature, so as to allow the relative movements of the bonded parts while working in shear.
• the support plate 15 and the active part of the lateral face 14 must, this time, be imperatively held against one another by means allowing their separation in a non-destructive manner, such as those already cited as an example for the lateral face. 1 of the prior art (bolting, cradle).
• the side face 14 according to the invention is mounted on the casting machine, in the position shown in FIG. 2a, and used in the usual way for a first casting.
• the front face of the active part is found in the state previously described (and shown in FIG. 1 a) of the front face of the active part of the lateral face 1 of the prior art.
• the cylinders have worn the outer edges of the insert 22 to a thickness "e” and a width "1", the core 21 has been hollowed out by chemical and mechanical erosion due to liquid metal, and solidified metal 13 covers the less in places the front face of the active part.
• the active part of the lateral face 14 is detached from the support plate 15, then turned over and replaced on the support plate 15.
• the heart 21 and the insert 22, which constituted the front face of the active part during the first casting can constitute the rear face during a second casting.
• the core 21 ′ and the insert 22 ′, which formed the rear face of the active part during the first casting constitute the front face during this second casting.
• the recess 17 in the support plate 15 must meet the following conditions. Its depth must be sufficient for the parts of the insert 22 and of the core 21 which are in relief with a thickness equal to "e" (or possibly greater than "e” in the areas where solidified metal 13 is present) with respect to the worn outer edges of the insert 22 can be housed there after the active face has been turned over. In other words, the depth of the recess 17 must be greater than the sum of "e” and the maximum thickness of the layers of solidified metal 13. It is therefore necessary to estimate at least roughly the maximum values that these parameters may take when the first casting, and fabricate the support plate 15 accordingly.
• said central plate 25 is a simple flat plate whose contour matches that of the insert 22-core assembly 21.
• the cohesion of the assembly of the active part of the lateral face 24 is ensured by a belt of metallic preference 26 analogous to the belt 1 1 of the side face 1 of the prior art previously described, while the configuration of the side face 14 of the previous example amounted to integrating such a belt into the central plate 18 itself .
• the presence of a belt 26 independent of the central plate 25 is advantageous in that it makes it possible to facilitate the cohesion of the central plate 25 even in the event of rupture thereof.
• the fourth example of a lateral face according to the invention 28, represented in FIG. 5 in its initial state before the start of the first casting differs from the previous example in that the active part is formed only by a single element 29, the functions of which combine those of the core 21 and the insert 22 of the previous example.
• this element 29 must seal the casting space 12 by its contact with the cylinders, it must be made of a material for which the properties of resistance to wear and to corrosion by metal must be favored. . However, it must also, optimally, have as good insulating properties as possible and good resistance to thermal shock and to cracking, in order to have acceptable behavior in its central part. Materials such as boron nitride-SiAlON ® can be used for this purpose.
• the presence of a belt 26 surrounding the active part of the lateral face 28 is not essential, since this active part is in one piece and in principle its cohesion is ensured. However, such a belt 26 is still recommended, because it can minimize the consequences of a possible cracking of the element 29 during its use.
• the invention can be applied not only to installations for casting between rolls, but also to all types of installations for casting thin metal strips using lateral faces according to the previously cited prior art which are applied against the edges walls in cooling running, such as casting installations between strips.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Continuous Casting (AREA)
• Coating With Molten Metal (AREA)
• Casting Devices For Molds (AREA)
• Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
• Treatment Of Steel In Its Molten State (AREA)
• Examining Or Testing Airtightness (AREA)
• Rod-Shaped Construction Members (AREA)

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• 1998
  • 1998-12-21 FR FR9816185A patent/FR2787360B1/fr not_active Expired - Fee Related
• 1999
  • 1999-12-17 ES ES99961097T patent/ES2183632T3/es not_active Expired - Lifetime
  • 1999-12-17 AT AT99961097T patent/ATE223270T1/de active
  • 1999-12-17 JP JP2000589296A patent/JP4567200B2/ja not_active Expired - Fee Related
  • 1999-12-17 DE DE69902820T patent/DE69902820T2/de not_active Expired - Lifetime
  • 1999-12-17 WO PCT/FR1999/003175 patent/WO2000037198A1/fr active IP Right Grant
  • 1999-12-17 DK DK99961097T patent/DK1144142T3/da active
  • 1999-12-17 US US09/868,038 patent/US6488075B1/en not_active Expired - Fee Related
  • 1999-12-17 KR KR1020017007598A patent/KR100664431B1/ko not_active IP Right Cessation
  • 1999-12-17 BR BR9916389-6A patent/BR9916389A/pt not_active IP Right Cessation
  • 1999-12-17 AU AU17829/00A patent/AU753213C/en not_active Ceased
  • 1999-12-17 PT PT99961097T patent/PT1144142E/pt unknown
  • 1999-12-17 EP EP99961097A patent/EP1144142B1/de not_active Expired - Lifetime
• 2000
  • 2000-01-26 TW TW089101267A patent/TW445182B/zh not_active IP Right Cessation

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