EP2014393A1 - Mould for strand casting of blooms, cogged blooms or billets - Google Patents

Abstract

A mold for the continuous casting of blooms, slabs or billets is provided with a mold tube (2) and a surrounding support jacket (4). The mold tube (2) is supported on the support casing (4) via support profiles (15) extending in its longitudinal direction and distributed over the circumference and is connected in a form-fitting manner to this via connecting profiles (20) extending in the longitudinal direction. The connecting profiles (20) are each formed as from the outer circumference of the mold tube (2) to the outside and from the inner periphery of the support jacket (4) inwardly projecting profile strips (21, 22) which engage in such a way that in the circumferential direction of the mold a game is present. As a result, the stresses caused by the thermal expansion, permanent deformation and fatigue cracks in the mold tube are largely avoided.

Description

The invention relates to a mold for the continuous casting of billets, slabs or billets according to the preamble of claim 1.

Continuous casting molds are known to be subject to significant thermal stresses during operation due to the solidified in Kokillenhohlraum liquid metal. The latter consequently cause thermal expansions of the mold walls and thus lead to deformations of the precisely produced mold cavity. Particularly undesirable are deformations transverse to the casting direction, because they change the important for the solidification Kokillenkonizität. It is therefore necessary to take special measures to stabilize the mold walls in their position.

From the generic EP-B1-1 468 760 it is known to arrange the supporting cavity of the mold cavity mold tube made of copper, on which the mold tube is supported via support profiles extending in its longitudinal direction and distributed over the circumference. The mold tube is positively connected to the support jacket via longitudinally extending connection profiles, wherein between the mold tube and the support jacket cooling channels are arranged for guiding cooling water, which are limited by the support profiles and / or the connection profiles. The connection profiles are formed, for example, as dovetail or T-profiles, which engage in corresponding grooves of the support jacket. Inserted into the grooves they are in the longitudinal direction of the mold. This assembly is not always easy because it comes to friction on between the mold walls and the support shell provided sealing elements. The mold tube walls are each not only held in the direction perpendicular to the casting axis, but also prevented from thermal expansion in the wall or support plane, transverse to the casting axis. The latter can lead to tensions and permanent deformations and fatigue cracks of the mold tube.

The present invention has for its object to provide a mold of the type mentioned above, which has a high dimensional stability in the casting operation, and in which nevertheless caused by thermal expansion of the mold walls deformations can be largely avoided.

This object is achieved by a mold with the features of claim 1.

Further preferred embodiments of the inventive mold form the subject of the dependent claims.

According to the invention, the connection profiles are in each case designed as two profiled strips protruding inwards from the outer circumference of the mold tube and projecting inwardly from the inner circumference of the support casing, which interlock in such a way that a clearance is present in the circumferential direction of the mold. Through the profile strips, the Kokillenrohrwände are held on the supporting walls of the protective jacket in the direction perpendicular to the casting axis, however, a thermal expansion caused by displacement along the mold wall is possible, especially in Kokillenlängsrichtung, but also within the scope of the proposed game across, in Circumferential direction of the mold. As a result, the stresses caused by the thermal expansion, permanent deformation and fatigue cracks in the mold tube are largely avoided. Last but not least, the assembly of the mold is simplified.

Fig. 1

in perspektivischer Darstellung ein Ausführungsbeispiel einer erfindungsgemässen Kokille mit einem Kokillenrohr und einem aus vier Stützplatten zusammengesetzten Stützmantel;

Fig. 2

die Kokille nach Fig. 1 im horizontalen Querschnitt;

Fig. 3

einen der Fig. 2 entsprechenden horizontalen Teilschnitt im vergrösserten Massstab;

Fig. 4

die Kokille nach Fig. 1 im vertikalen Querschnitt nach Linie IV-IV in Fig. 2;

Fig. 5

eine der Stützplatten in perspektivischer Darstellung;

Fig. 6

ein zweites Ausführungsbeispiel einer erfindungsgemässen Kokille im horizontalen Querschnitt;

Fig. 7a, 7b, 7c

eine Stützplatte und einen Teil des Kokillenrohres mit weiteren zwei Stützplatten voneinander getrennt sowie in einem zusammengebauten Zustand gemäss einem weiteren Ausführungsbeispiel;

Fig. 8a, 8b

im horizontalen Querschnitt ein erstes Ausführungsbeispiel von Verbindungsprofilen zur Verbindung des Kokillenrohres mit dem Stützmantel;

Fig. 9a, 9b

im horizontalen Querschnitt ein zweites Ausführungsbeispiel von Verbindungsprofilen zur Verbindung des Kokillenrohres mit dem Stützmantel;

Fig. 10

eine Kokillenplatte für eine Plattenkokille mit einer entsprechenden Stützplatte;

Fig. 11

eine weitere Ausführungsform einer Kokillenwand für eine Plattenkokille mit entsprechenden Stützplatten;

Fig. 12

ein Ausführungsbeispiel einer erfindungsgemässen Kokille in perspektivischer Darstellung mit einem Kokillenrohr und vier Stützplatten, und

Fig. 13

ein weiteres Ausführungsbeispiel eines im Querschnitt rechteckförmigen Kokillenrohres mit Stützmantel im horizontalen Querschnitt.

The invention will be explained in more detail with reference to the drawing. Show it:

Fig. 1

a perspective view of an embodiment of an inventive mold with a mold tube and a composite of four support plates supporting jacket;

Fig. 2

the mold after Fig. 1 in horizontal cross section;

Fig. 3

one of the Fig. 2 corresponding horizontal partial section on an enlarged scale;

Fig. 4

the mold after Fig. 1 in vertical cross-section along line IV-IV in Fig. 2 ;

Fig. 5

one of the support plates in perspective view;

Fig. 6

A second embodiment of a mold according to the invention in horizontal cross-section;

Fig. 7a, 7b, 7c

a support plate and a part of the mold tube with another two support plates separated from each other and in an assembled state according to another embodiment;

Fig. 8a, 8b

in horizontal cross section, a first embodiment of connecting profiles for connecting the mold tube with the support shell;

Fig. 9a, 9b

in horizontal cross section, a second embodiment of connecting profiles for connecting the mold tube with the support shell;

Fig. 10

a mold plate for a plate mold with a corresponding support plate;

Fig. 11

a further embodiment of a mold wall for a plate mold with corresponding support plates;

Fig. 12

an embodiment of a mold according to the invention in a perspective view with a mold tube and four support plates, and

Fig. 13

a further embodiment of a rectangular cross-section mold tube with support jacket in horizontal cross-section.

In Fig.1 to 4 a mold 1 for continuous casting of rectangular cross-section blooms, slabs or billets is shown, which has a mold tube 2 made of copper, which forms a mold cavity 3, and a surrounding the mold tube 2 support jacket 4. The support shell 4 is composed of four support plates 5, 5 ', which are connected to each other by means of screws 6. Between the mold tube 2 and the support shell 4 cooling channels 10 are provided for guiding cooling water, which form part of a water circulation cooling for the copper pipe, form ferrohr, and which are distributed over the entire circumference and substantially over the entire length of the mold tube 2 (see, in particular Fig. 2 and 4 ). The support plates 5, 5 'are provided in the upper and in the lower region with connected to the cooling channels 10 inlets and outlets 11, 12 for the cooling water.

In the illustrated embodiment, the cooling channels 10 are embedded in the outer peripheral surface of the mold tube 2, for example milled. The mold tube 2 is supported, on the one hand, by supporting profiles 15 extending in the longitudinal direction L and distributed over the circumference on the support jacket 4 or on the support plates 5, 5 ', and on the other hand is in contact with these support plates 5, 5' via connecting profiles 20 extending in the longitudinal direction in a detachable, positive connection. The cooling channels 10 are bounded laterally by the support profiles 15 and / or the connection profiles 20.

According to the invention, the connection profiles 20 are designed in each case as two profiled strips 21, 22 protruding inwardly from the outer circumference of the mold tube 2 and projecting inwards from the inner circumference of the support jacket 4. They are distributed over the respective Kokillenseite, wherein their number per page depends on the mold size. In the case of the cross-sectionally rectangular mold 1 are for example according to Fig. 2 the wider support plates 5, each with four and the narrower support plates 5 ', each equipped with two connecting profiles 20.

The profiled strips 21, 22 are preferably nose-shaped in cross-section (as described below with reference to FIG Fig. 8a, 8b and 9a, 9b will be described) and interlock such that in the circumferential direction of the mold 1 a game is present. The mold walls are in the on the held the support plates 5, 5 'adjacent position in the direction perpendicular to the casting axis, but it is possible due to thermal expansion mutual displacement along the mold wall possible, especially in Kokillenlängsrichtung L, but also in the context of the proposed game across it, in the circumferential direction of mold. In order to enable this displacement, the mold tube 2 is held in its corner regions with a corresponding clearance relative to the support jacket 4. Each of the support plates 5, 5 'is advantageously equipped in its peripheral region with a cooling zone sealing the sealing ring 23, 23', in a Fig. 5 showing the support plate 5, shown channel 24 is inserted.

While the profile strips 21 made directly on the mold tube 2, ie are integral with the mold tube 2, especially in large molds and in the presence of the sealing rings 23, 23 'mounting technology advantageous to run the moldings 22 for the support plates 5, 5' separately, as on Example after Fig. 2 to 4 shown. These are then inserted into corresponding recesses 25 of the support plates 5, 5 'and connected to the support plates 5, 5' by means of screws 26 distributed over the entire strip length. In this case, during assembly no lateral displacement of the support plates 5, 5 'on the sealing rings 23, 23' necessary because the previously inserted profile strips 22 only on the support plates 5, 5 'must be tightened.

As in FIGS. 6 and 7a . 7b, 7c However, it is quite possible, especially for smaller molds, to make the profiled strips 22 for the support plates 5, 5 'directly on the support plates 5, 5', ie in one piece with the respective support plate 5, 5 '.

At the in Fig. 6 shown, smaller mold 1 'square cross-section is only one of two interlocking profile strips existing connection profile 20' per mold side (and a plurality of support profiles 15 ') are present. The connecting profiles 20 'connecting the mold tube 2' to the support jacket 4 'are each arranged in the middle region of the respective mold wall.

According to requirements, according to Fig. 7a, 7b . 7c a plurality of connecting profiles 20 "can also be provided per mold side, which consist of profiled strips 21" integrally formed with the mold tube 2 "and profiled strips 22" formed integrally with the respective supporting plate 5. The mold tube 2 "can have only one supporting profile 15 arranged in the middle region per side "or more support profiles 15" have.

According to the embodiments FIGS. 6 and 7a . 7b, 7c If the respective support plate 5 "during assembly must be moved laterally relative to the Kokillenrohrwand until the engagement of the profile strips 21", 22 ".Also in the presence of sealing rings, the assembly is much easier than in the case of EP-B1-1 468 760 known molds, the lateral displacement in the novel mold is not to be compared in size with the longitudinal displacement during assembly according to the EP-B1-1 468 760 , In addition, the respective support plate 5 "can be set slightly inclined until it engages, thereby avoiding the friction on the sealing ring.

Particularly advantageous cross-sectional shapes of the profile strips 21, 22 are made Fig. 8a, 8b and 9a, 9b seen. The cross-sectional nose-shaped profiled strips 21, 22 project by an amount a from a base surface 27 or 28 of the mold tube 2 and the support plate 5, respectively. The profile strip 21 of the Ko-21 of the mold tube 2 has a support surface 29, with which it rests in the assembled state on the base surface 28 of the support plate 5 and vice versa, the support plate 5 comes with a support surface 30 on the base 27 of the mold tube 2 to the plant. The profiled strips 21, 22 each have a directed in the circumferential direction of the mold, rounded nose 31 and 32 with a radius r ₁ , which is engaged by a likewise rounded, the nose in the circumferential direction opposite recess 33 and 34 with a radius r ₂ , The Radis r _{2 of} the recesses 33, 34 is slightly larger than the radius r _{1 of} the two lugs 31, 32. When joining the two profile strips 21, 22, the nose engages the one in the recess of the other profile strip, with a lateral clearance of, for example, ± 0.1 mm, which results from the difference between the two radii r ₁ , r ₂ , so that in the context of this game, a thermal expansion caused by mutual displacement along the mold wall in the circumferential direction of the mold can take place.

Of course, a mutual displacement caused by thermal expansion in the longitudinal direction of the profile strips 21, 22, i. in the longitudinal direction of the mold possible. In this way stresses, plastic deformations and fatigue cracks in the mold tube, which are otherwise caused by the thermal expansion, can be avoided.

For the size of the lateral game, the mold size is crucial. For larger molds, a larger game must be guaranteed. A possible cross-sectional shape of the nose-shaped profiled strips 21, 22 for larger molds is in Fig. 9a, 9b shown, where the nose 31 'and 32' of a profile strip 21 and 22, respectively in the recess 34 'and 33' of the other profile strip 22 and 21 with a larger game in the circumferential direction Richrich can intervene.

Instead of a one-piece mold tube 2 or 2 'or 2 ", it is also possible and quite usual to assemble the mold cavity forming the mold cavity as a plate mold with individual copper plates or otherwise shaped mold tube walls associated with a plurality of support plates which form the support shell around the plate mold around.

Fig. 10 shows as an example a mold plate 42 a plate mold for continuous casting of thin slabs. The long sides of such molds are 1 to 2 m and the narrow sides only 50 to 10 mm wide. The long-side mold plates 42 are provided in the upper region with a bulge 50 for the dip tube, ie the mold tube wall is not straight everywhere. Also, the mold plate 42 associated with the support plate 45 is provided on the inside with a corresponding recess 51. Between the mold plate 42 and the support plate 45, in turn, the cooling channels 10 are provided, which are bounded by the support profiles 10 and / or the connection profiles 20.

According to the invention, the connecting profiles 20 are again designed as two interlocking profiled strips 21, 22 with lugs 31, 32 which engage in the circumferential direction of the chill and intermesh with play. In the oblique region of the bulge 50 and the recess 51 and the lugs 31, 32 are directed obliquely, parallel to the Kokilleninnenfläche 50 a, 50 b. Thus, even this wide and relatively thin copper plate, which is subjected to significant thermal expansion over the more solid steel backing plate, is given the opportunity to actually expand along the mold wall. In this variant, it is self-evident advantageous to perform the profile strips 22 for the support plate 45 separately and insert into the support plate 45.

Fig. 11 FIG. 5 illustrates a copper mold tube wall 52 of a plate mold for continuous casting of double T pre-profiles, which has a web part 52a, two flange parts 52b, and an oblique part 52c connecting the web part 52a to the respective flange part 52b. The web portion 52a is associated with a support plate 55a. The flange 52b are each equipped with a support plate 55b. Between the support plate 55a for the web portion 52a and the support plate 55b for the flange portions 52b, a support plate 55c extending along the inclined portions 52c is disposed and overlapped by the adjacent support plates 55a, 55b. Again, the support profiles 10 and / or the connection profiles 20 are present, the latter as two interlocking profile strips 21, 22 formed with in the circumferential direction of the mold and interlocking with play lugs 31, 32. The lugs 31, 32 are also always directed parallel to the Kokilleninnenfläche in the circumferential direction of the mold, even in the region of the inclined portions 52c. Unlike the execution after Fig. 10 However, the profile strips 22 are always perpendicular to the respective wall part. Thus, in this mold form, the thermal expansion of the individual mold walls of the mold tube is taken into account in their entire range.

Both at the plate mold after Fig. 10 as well as with those Fig. 11 are the lugs 31, 32 arranged symmetrically with respect to the transversely to the longitudinal extent of the elongated mold running center plane (A).

Fig. 12 shows a mold tube 60 with a mold cavity 3, which in itself the same as that after Fig. 1 to Fig. 5 designed and therefore not explained in detail. As a special feature, however, the support plates 61, 62 are not formed as a support casing forming a box, but they are independently secured by means of the inventive profile strips on the respective present four outer walls 60 'of the mold tube 60. These support plates 61, 62 are advantageously configured trapezoidal in horizontal cross-section and form a plane surface resting on the respective outer wall 60 'of the tube 60, so that the cooling channels 10 milled on the outside are covered by the same in the tube 60. These support plates 61, 62 thus form only a kind of stiffening of the relatively thin-walled mold tube.

The mold tube 60 is held together with the support plates 61, 62 in a mold housing, not shown in detail, which is divided into two and for this purpose may have a center flange, not shown, which surrounds the support plates 61, 62. The cooling water in the interior of the mold housing is passed on the bottom through the cooling channels 10 of the tube upwards and passes on the top again into the mold housing.

With this variant Fig. 12 This results in a simplified embodiment of a mold in particular because the support plates 61, 62 are not connected to each other. Of course, these support plates could also be designed differently, for example by the cooling channels would be assigned to these support plates.

Another mold 1 "with an elongated rectangular cross-section according to Fig. 13 has a mold tube 71 and a surrounding this Supporting jacket 74, wherein the support jacket 74 is divided in its longitudinal direction at the points 74 'is thus made of four shell parts, which are screwed together at these points 74'.

The special feature of this mold 1 "is that according to the invention only two connecting profiles 70 are provided on the two elongated sides of the mold 1", which are arranged symmetrically to the central axis A of the longitudinal sides. These connection profiles 70 are the same as those after Fig. 2 trained and therefore not explained again in detail. Due to the relatively thin wall of the support jacket 74 70 longitudinal profiles 76 and also transverse profiles 77 are welded on its outer side in the connection profiles. The longitudinal profiles 76 are held in place by screws. Of course, more than two such connection profiles 70 could be assigned per page.

Claims (16)

Mold for continuous casting of billets, slabs or billets, with one or one of a support shell (4; 4 ') and support plates (61, 62) surrounding mold tube (2; 2', 2 ") and plate mold, wherein the mold tube (2, 2 ', 2 ") or the plate mold over in its longitudinal direction (L) extending and distributed over the circumference supporting profiles (15, 15', 15") on the support shell (4, 4 ') and on the support plates ( 61, 62) and is connected in a form-fitting manner with this connection profile (20; 20 '; 20 ") extending longitudinally, wherein between the mold tube (2; 2';2") or the plate mold and the support jacket (4; 4 ') or support plates (61, 62) through the support profiles (15; 15', 15 ") and / or the connection profiles (20; 20 ';20") are arranged limited cooling channels (10) for guiding cooling water, characterized marked that
the connecting profiles (20, 20 ', 20 ") in each case as outwardly from the outer circumference of the mold tube (2, 2', 2") or the plate mold and from the inner circumference of the support jacket (4, 4 ') or the support plates (61, 62) inwardly projecting profile strips (21, 22, 21 ", 22") are formed, which engage in such a way that in the circumferential direction of the mold a game is present. Chill mold according to claim 1, characterized in that the profiled strips (21, 22; 21 ", 22") are nose-shaped in cross-section, with one nose (31, 32, 31 ', 32') directed in the circumferential direction of the chill Profile strip (21, 22, 21 ", 22") in one of the nose (32, 31, 32 ', 31') of the other profile strip (22, 21; 22 ", 21") engaging behind recess (33, 34; 33 ' , 34 ') engages. Chill mold according to claim 1 or 2, characterized in that the mold tube (2, 2 ', 2 ") has a square or rectangular cross section and the support jacket (4, 4') consists of four support plates (5, 5 ', 5", 61, 62), wherein each Kokillenseite a arranged in the central region, two interlocking profile strips comprehensive connection profile (20 ') or more such connection profiles (20; 20 ") - are distributed over the Kokillenseite - assigned. Chill mold according to claim 3, characterized in that the profiled strips (21 ", 22") forming the connecting profiles (20 ', 20 ") are formed integrally with the mold tube (2', 2") or with the respective support plate (5 ") are. Chill mold according to claim 3, characterized in that the support plates (5, 5 ') associated profile strips (22) in each case in a recess (25) of the support plate (5, 5') and connected to the support plate (5, 5 ') , preferably screwed. Chill mold according to one of claims 3 to 5, characterized in that the mold tube (2, 2 ', 2 ") in the corner region of the support jacket (4, 4') is kept with play. Chill mold according to one of claims 1 to 6, characterized in that the profiled strips (21, 22; 21 ", 22") extend substantially over the entire length of the mold tube (2, 2 ', 2 ") and of the support jacket (4; 4 ') extend. Chill mold according to Claim 1 or 2, characterized in that the plate mold forming the mold cavity is composed of a plurality of copper plates (42) or plate-shaped mold tube walls (52), each plate (42) or mold tube wall (52) having one or more Assigned to support plates (45, 55a, 55b, 55c) and connected thereto via the interlocking profile strips (21, 22) formed connecting profiles (20). Chill mold according to claim 8, characterized in that the profiled strips (21, 22) are nose-shaped in cross-section, wherein in each case a directed in the circumferential direction of the mold nose (31, 32) of a profile strip (21, 22) in a nose (32 , 31) of the other profiled strip (22, 21) engages behind engaging recess (33, 34, 33 ', 34'), wherein the lugs (31, 32) in each region of the Kokillenrohrwand (52) is directed parallel to this wall part. Chill mold according to claim 9, characterized in that the lugs (31, 32) are arranged symmetrically with respect to the transverse to the longitudinal extent of the mold extending center plane (A). Chill mold according to claim 1, characterized in that support plates (61, 62) are provided which are fixed independently of each other by means of the profile strips on the respective outer walls (60 ') of the mold tube (60). Chill mold according to claim 11, characterized in that the support plates (61, 62) rest on the mold tube (60) such that the outside milled cooling channels (10) are covered by the support plates at the tube (60). Mold tube for a mold according to one of claims 1 to 7, characterized in that connecting profiles (20; 20 ', 20 ") are provided which are each designed as outwardly projecting profile strips (21; 21"). Shaped mold for a mold according to one of claims 1, 8, 9 or 10, characterized in that connecting profiles (20) are provided which are each designed as outwardly projecting profile strips (21; 21 "). Supporting plates for a mold according to one of claims 1 to 12, characterized in that connecting profiles (20; 20 ', 20 ") are provided which are each designed as inwardly projecting profile strips (22; 22"). Chill mold according to claim 1, characterized in that only two opposite sides of the mold (1 ") are associated with connection profiles (70), preferably in a symmetrical arrangement to the central axis A of these pages.

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