FR2636259A1 - SIDE WALL FOR A CONTINUOUS CASTING INSTALLATION BETWEEN MOBILE WALLS AND INSTALLATION COMPRISING SAID WALL - Google Patents

Abstract

Side wall for a device for the continuous casting between moving walls of metal products, in particular thin products, device comprising two cooled moving walls facing each other and driven simultaneously in the same direction 3, 4 and two of said side walls 6 delimiting the space of casting, characterized in that the side wall comprises in the vicinity of the movable walls 1, 2, two inserts 7, 8 made of material of good thermal conductivity, which adjoin the edge 11 of the movable walls, have a face 73, 83 directed towards the casting space, extend to the vicinity of the neck 5 between the movable walls, and delimit between them a zone consisting of a coating of thermally insulating material 9. The invention applies in particular to continuous casting between cylinders of thin steel products.

Description

IATAL WALL FOR CONTINUOUS CASTING INSTALLATION BETWEEN WALLS

  The present invention relates to a continuous casting plant for thin metal products and in particular steel, between moving walls, in particular between rolls, and more particularly the common side walls designated by the term 'small faces'. ", 'delimiting the nearby casting space

  lateral edges of said movable walls.

  A common problem with the different types of continuous casting installation between moving walls is to seal the lateral ends of the casting space

between the moving walls.

  Another problem is to avoid the hanging of the cast metal on the side walls, this hanging likely to cause

  breakthroughs on the edges of the cast product.

  Another problem is to avoid the formation of a solidified corner in contact with these walls above the neck, that is to say the level of the narrowest passage between the movable walls.

  To solve these problems, it has already been proposed to use

  thermally insulating side walls, in order to limit the solidification initiating their contact, and thus to avoid the formation of said corner. A device of this type is described in particular in the French patent application No. 87 05234 in the name of

  the holder of this application.

  It is also known, in particular from the documents US 303 8219 and EP 212 423, to arrange the lateral walls in

  body, that is to say whose surfaces deviate symmetrically

  from each other to the collar. This arrangement allows in particular the lateral expansion of the product as it approaches the neck, this expansion being caused by the rolling effect of the corner too early solidified or in

solidification course.

  These provisions do not, however, prevent liquid metal infiltration between side walls and

  mobile walls, the solidification being poorly controlled at this level.

  Indeed, if the side wall is sufficiently insulating to prevent solidification of the metal cast on contact, metal

  liquid can seep at the sidewall junction -

  mobile wall. In addition, the materials used to make these highly insulating side walls generally have little mechanical strength. They are, as a result, quickly worn down by the friction of the metal and the ends of cylinders, which

  which further favors infiltrations.

  If, conversely, the side walls are less insulating,

  the cast metal solidifies upon contact, but this solidification

  difficult to control, problems of

  adhesion or irregularity of the edges of the product may

  remain, even in the case of flanking side walls.

  The object of the present invention is to remedy the drawbacks

  above mentioned and to promote cooling over the entire width of the cast product and in particular on the edges of its long sides, without, however, creating premature solidification.

in contact with side walls.

  With these objectives in view, the object of the present invention

  is a side wall for a continuous casting device

  bare thin metal products between moving walls, compor--

  as two cooled moving walls facing each other and driven

  simultaneously in the same direction, and two of said side walls

  boundaries defining the casting space.

  According to the invention, the side wall is characterized

  in that it comprises, in the vicinity of the movable walls, two inserts made of material of good thermal conductivity, which adjoin the edge of the movable walls, have a face directed towards the casting space, extend to near the collar between said movable walls, and delimit between them an area consisting of a coating of thermally insulating material. Thanks to the device according to the invention, the solidified metal skin in contact with the cooled moving walls is extended on the face of the inserts directed towards the casting space. The resulting continuous skin covers the seal between the moving wall and

  inserts, thus preventing infiltration of liquid metal.

  In addition, skin does not form on contact with the inter-

  inserts of the side walls, since it is very insulating.

  According to a particular embodiment of the invention, the surface of the side wall facing the casting space is undercut, the inserts penetrate the casting space between the movable walls and their faces facing the space.

  of casting are generally inclined with respect to a plane perpendicular to

  of the mobile walls, this inclination gradually decreasing from the upper end to the end

  bottom of the inserts, o their said faces opposite the

  casting space are substantially perpendicular to the moving walls. In this arrangement, the draft of the side walls

  allows lateral expansion of the edges of the cast product. simulta-

  temporarily, because of the decrease of the inclination of the faces of the inserts, the skin which is formed is progressively plated by the ferrostatic pressure against the moving walls,

  in order to form near the neck level, two skins of thick

  substantially constant over the entire width of the product.

  This particular arrangement makes it possible in particular to minimize

  the forces exerted on the walls of the cylinders,

perpendicular to them.

  Indeed, if from the level of the liquid metal, solidification

  cation of the edges of the skin forms tabs perpendicular to the wall of the rolls, these tongues tend to thicken when approaching the neck and the ferrostatic pressure may be insufficient to flatten them uniformly against the cooled walls of the cylinders, resulting in irregularities

  solidification, and also a greater effort to close

  mite of the neck where the tongues meet and tend to be rolled '. In addition, if these tabs do not stick well on the cooled walls, the seal is no longer assured between

  cylinder and side wall, and liquid metal may leak

  between the tongue and the adjacent side wall. The risk

  practically eliminated by the special provision

above.

  The invention will be better understood and other characteristics

  ticks and benefits will appear on reading the description

  which will be made of a preferential mode of realization of the in-

  vention, in the case of casting between rolls.

  Referring to the accompanying drawings in which: - Figure 1 is a partial schematic representation of a continuous casting installation between cylinders, showing the disposition of a side wall according to the invention; - Figure 2 is a sectional view along the plane II -II of Figure 1; FIGS. 3 to 6 are diagrams showing the evolution of the solidification of the product at the different levels indicated in FIG. 2; FIG. 7 is a plan view of a side wall

  particularly suitable for a casting device according to the invention.

  vention; - Figure 8 is a vertical sectional view of this wall, along the line VIII-VIII of Figure 7; - Figure 9 is a sectional view of this wall at the line IX-IX; FIG. 10 is another horizontal sectional view,

according to X - X of Figure 7.

  The schematic drawings of Figures 1 to 6 are given

  purely as a tutorial and it will be understood that the dimensions

  the various elements have not been voluntarily respected in order to facilitate

  the object of the invention and the aims pursued.

  In Figure 1 is shown an end of an installation

  continuous casting process between cylinders, comprising two

  lindres 1 and 2, the second of which was only symbolized by

  trace 21 of the end of its wall.

  The two cylinders, parallel axes and located in a

  same horizontal plane P, are rotated in the opposite direction

  milking according to the arrows 3 and 4, and spaced at the neck 5, corresponding to the level of the plane P passing through the axes of the cylinders, a distance corresponding to the thickness of the cast product. The supply of liquid metal is, according to one of the well-known methods, in the casting space delimited, on the one hand, by the portion of the walls of the cylinders located above the neck and on the other hand , by the side walls located at

  edges of the cylinders and in sealing contact with said edges.

  It is clear that the side walls being fixed and the walls of the movable cylinders, a minimum functional clearance must be respected between them to avoid intense friction and wear that would result. As a result, the watertightness can not be absolute and liquid metal infiltration risks

  to occur. The reduction of the risk of infiltration is

  one of the purposes of the present invention.

  Indeed, if the side wall is constituted as indicated at the beginning of this memory, a sufficiently insulating material so that the liquid metal does not solidify on contact, the solidified metal skin in contact with the cooled walls of the cylinders

  just stop at the joint between side wall and cy-

  lindre, and the risk of infiltration at this level is great.

  The idea behind the present invention is precisely

  to seal the liquid metal by promoting the extension of the solidified skin on the side of the side wall directly adjacent to the cylinders. This is the solidified skin that covers the seal between cylinder and wall

  side, which constitutes a watertight wall preventing infil-

  tions. In Figure 1 is shown a side wall, or "small face" 6, consisting of a vertical flat plate 61 held with a functional play against the ends of the cylinders 1 and 2. This plate 61 carries two inserts 7, 8 of material good thermal conductivity. Each insert is a slat of small thickness, preferably close to half the thickness of the cast product, curved according to the curvature of the rolls, and protrudes from the plate 61 towards the inside of the casting space so as to fit the edge 11 of the cylindrical wall. The lower ends 71, 81 of the inserts of one and the same side wall meet at a level preferably located slightly above the neck 5. The width of the inserts protruding from the plate 6 decreases steadily from their ends.

  upper 72, 82, to their lower ends 71, 81.

  The face 73, 83 of the inserts, facing the casting space, is, at any level, inclined relative to the generator of the

  cylinder at this level, this inclination increasing

  gressively from the upper ends of the inserts to their lower ends where it is close to 900. In other words, the face 73, 83 of each insert is a left surface of which

  a horizontal generatrix forms with the corresponding generator

  adjacent cylinder, an obtuse angle, for example about

  135 ", at the upper end 72, 82, this decreasing angle pro-

  gressively down to be substantially equal to 900

at the lower end.

  The zone situated between the inerts of the same small face consists of a plate or a coating of insulating refractory material 9, whose surface 91 facing the casting space is preferably flat and inclined relative to vertically to form the previously reported body and clearly visible in Figure 2, so as to form a continuous surface with the faces 73, 83 of the inserts, without asperities at their junction lines. Advantageously, the refractory material 9 is cured on the surface to prevent excessive wear

fast by the cast metal.

  It will of course be understood that during casting, the level of liquid metal must be kept below the limit

  upper inserts and refractory material.

  The lower ends of the inserts may form, as indicated in FIG. 2, a sharp recess 62 through

  compared to plate 61, similar to that shown in the document

  EP 212 423 already cited, which allows, at the level of the collar,

  the free lateral expansion of the edges of the cast product. We prefer

  however, as will be described in more detail by

  following this memorandum, ensure continuity between the

  faces of the inserts 73, 83 and the refractory material 91, and the

  wall portion 63 immediately underlying.

  The faces 73, 83 of the inserts may also be plane in the same plane as the surface 91 of the refractory material.

  insulation 9, which simplifies the production of said inserts.

  The continuity of the solidified skin at the seal between cylinders and inserts is also ensured. However, this provision is less favorable to training and

  said skin, in accordance with the description which

  will be made in connection with Figures 3 to 6.

  These figures are horizontal sections of the installation.

  casting, during casting, at different levels.

res in Figure 2.

  Figure 3 schematically shows a section at level iII near the level N of the liquid metal. In contact with the cooled walls of the cylinders 1 and 2, the molten metal 10 solidifies and forms, on each cylinder, a thin solidified skin 101, 102. This skin is extended by a tongue 103, 104, solidified in contact with the inserts 7, 8 which are thermally conductive and cooled because of their proximity to the cooled walls of the rolls and the contact with the metal mass of the plate 61. On the other hand, the cast metal does not tend to solidify in contact with the refractory material 9 insulation. It is noted that the solidified skin seals as soon as the upper level at point 105, 106

between cylinders and inserts.

  Figure 4 is a section at the intermediate level IV

  when the skin 101, 102 reaches this level because of its

  by the walls of the rotating cylinders. Simultaneously, the tongues 103, 104 accompany this movement by sliding

on the faces 73, 83 of the inserts.

  The cooling of the cast metal continues and the thick

  the skin 101 ', 102' and the tongue 103 ', 104' increases.

  The width of the face 73, 83 of each insert is reduced due to the increase of its inclination relative to the wall of the cylinder. Simultaneously, the contact width of the solidified skin with the cylinder increases due to the clearance of the side wall, and the tongue is applied as and when

  against the wall of the cylinder under the effect of the ferro-

  static. Due to the clearance of the surface 91 of the refraction

  9, the casting space widens.

  At level V of the lower extremity of the inserts (

  5), the thickness of the skin 101 ", 102" has further increased.

  The two tabs formed on each insert are applied to the walls of the cylinders and simultaneously join together

in 108.

  At the level of the collar (level VI, figure 6), the two skins

  are in full contact and form the product 109 of desired section.

  In this case, the lateral expansion of the edges caused by the rolling effect is allowed by the final increase in the width of the casting space, until it comes into contact with the portions.

of walls 63.

  As already understood, the device according to the invention: makes it possible to ensure the sealing of the casting space, allows the lateral expansion of the product,

  - controls the formation and evolution of the solidified skin

  and especially its edges (tabs), while avoiding the

  formation of a solid skin on the side walls.

  Figures 7 to 10 show an embodiment

  preferential of a small face according to the invention.

  In this embodiment, the plate 61 is constituted

  several elements assembled by screwing, so as to allow

  inserting the support of the inserts 7, 8. It comprises a flat support plate 64 on which are fixed, by screws 111 and held in position by centering pins 112, two bearing plates 65, 66 whose flat surface is intended to be placed facing the ends of the cylinders, and shaped so

  to have a curved edge 67, 68, of the same radius as the cymbals

  lindres and inscribed precisely in the extension of these.

263625 9

  The metal inserts 7, 8 are applied against the

  curved edges 67, 68, and in contact with the support plate 64.

  They are held in position by pegs 74 fixed in the bearing plates 65, 66 which penetrate into oblong holes 75 made in the inserts, so as to prevent the movement of these in the direction parallel to the axis of the cylinders, while allowing a slight displacement parallel to the edges of the support plates to allow longitudinal expansion

said inserts.

  The thickness of the inserts is constant (for example 2 mm).

  Their width varies from their upper extremities, where they de-

  edge of the plane of the surface of the support plates of some

  millimeters (5 to 10 mm, for example) at their lower ends

  where the overhang is much smaller (eg 1 to 2 mm). These values are only indicative and

  depend in particular on the overall dimensions of the installation.

  These values correspond to a relief of the inserts, and also of the refractory lining of the order of 1 to 3. The faces 73, 83 of the inserts 7, 8 are shaped as indicated above,

  in order to show a regular variation in their inclination

  its relative to the wall of the cylinders. The inserts thus have at their upper ends, an angled bevel section of about 45, this angle increasing down to

  form at the lower end a quadrangular section.

  An intermediate metal plate 69 whose two sides are shaped according to the curvature of the inserts, is inserted between them to hold them pressed against the curved edges 67, 68 of the bearing plates 65, 66. The intermediate plate 69

  is fixed by screws 113 on the support plate 64.

  The intermediate plate 69 has a thickness less than that of the support plates 65, 66, so as to allow the establishment against this plate 69, and between the inserts, an insulating refractory material 9 whose face 91 facing

  the casting space is flush with the faces 73 and 83 of the inserts.

  This insulating material may be a prefabricated plate and bonded to the intermediate plate 69, or it may be a material

  deposited in place, for example by projection.

  The lower extremities of the inserts of the inter-

  mediate 69, and insulating refractory lining 9, are located at the same level, slightly above the neck. At this level, the lower ends of the inserts are slightly spaced in order to maintain a certain width at the "tip" of the refractory insulating material, to avoid embrittlement of this tip. Below this level (corresponding to the level V of FIG. 2), the lateral wall is extended by a pad of

  guide 120, fixed by screws 114 on the support plate 64.

  The rear portion 121 of the guide shoe is inserted into corresponding recesses 122, 123, made in plates of bearing thickness 65, 66. The front portion 124 of the guide shoe is machined so as to have edges 125, 126 of curvature corresponding to that of the edges 67, 68 of the bearing plates 65, 66. The face of this guide pad, facing the cast product, has above the neck, a relief area 127 in the extension of the face 91 of the refractory lining 9,

  and below the neck (plane level P), a vertical planar area

  hold 128 located in the same plane as the surface of the plates

65, 66.

  The guide shoe 120 is made of a material

  having good wear characteristics,

for example cast iron.

  The particular configuration of the guide pad 120 which has just been described, especially with regard to the area

  127, has the advantage over the

  62, shown in Figure 2, to ensure the continuity of the side wall in contact with the cast product, and thus to avoid too rapid wear or tearing of the lower ends

  inserts and refractory lining.

  Of course, the invention is not limited to the embodiment described above by way of example. Technological changes may be made to the different elements

  components of the side wall and their method of assembly.

  For example, the inserts may be made of a non-exclusively metallic material, such as boron nitride compounds, BN with SiALON or Si3N4, or AlN a or

still SiC.

  It may also be provided that the face 91 of the coating

  refractory, instead of being flat, either concave or convex.

  It may also be provided that the inserts penetrate further between the cylinders, so that the guide shoe also enters between them and is therefore prominent by

compared to the support plates.

  We can also promote the formation of tongues

  solidified skin by a local cooling device

  placed near the inserts, support plates and / or

  the support plate, and also the pad.

Claims (6)

  1) Side wall for a continuous casting device   between moving walls of metal products, in particular   thin devices, device comprising two movable cooling walls   dies facing each other and driven simultaneously in the same direction (3, 4) and two of said side walls (6) delimiting   the casting space, characterized in that it comprises in the vicinity   swimming of the movable walls (1, 2), two inserts (7,8) of material of good thermal conductivity, which abut the edge (11) of the movable walls, have a face (73, 83) directed towards the casting space , extend to near the neck (5)   between the movable walls, and delimit between them a zone constituting   with a coating of insulating thermal material 9.   2) Side wall according to claim 1, characterized in that the surface (91, 73, 83) of the lateral wall facing   the casting space is undercut, the inserts (7, 8) are   penetrate into the casting space between the movable walls (1, 2) and their faces (73, 83) facing the casting space, are also inclined relative to a plane perpendicular to the movable walls, this inclination being reduced progressively from the upper ends (72, 82) to the lower ends (71, 81) of the inserts, o said faces (73, 83).   are substantially perpendicular to the movable walls.   3) Side wall according to claim 2, characterized   in that the clearance is approximately 1 to 3 '.   4) side wall according to claim 2, characterized in that the inclination of the faces (73,83) of the inserts opposite   casting space, at their upper end, is approximately   135 "to the generatrix of the adjacent movable wall.   5) Side wall according to one of claims 1 to 4,   characterized in that it comprises below the inserts and   refractory lining, and adjacent to their lower ends   a shoe (120) whose surface facing the casting space has above the neck 5, an area (127) stripped in the extension of the surfaces (91, 73, 83) of the inserts and the coating refractory, and below the neck 5, an area 128 vertical plane.   6) Continuous casting installation of metal products   between moving walls, particularly between cylinders,   characterized in that it comprises side walls according to one Claims 1 to 5.