JP4819038B2 - Cooling continuous casting mold - Google Patents

Abstract

The invention relates to a cooled continuous casting mold (1) for casting metal, especially steel, which has a casting format (GF) that is defined by respective two opposite broad faces (2, 3) and small faces (4, 5). The broad faces (2, 3) have a cooling area (6) which designed for the maximum casting width and comprises a plurality of cooling channels (7) extending in the direction of casting and being connected to a coolant circuit. The small faces (4, 5) can be adjusted to a predetermined casting format having a corresponding casting width. The aim of the invention is to provide a continuous casting mold for slab formats, especially thin slabs, which allows to adjust an even working end temperature of the broad sides and especially to reduce a considerable temperature drop in the neighborhood of the small faces while at the same time allowing to adjust different casting formats, especially smaller casting formats as compared to the maximum casting format. For this purpose, the cooling channels (7) and/or the inlet and/or outlet channels (8) of the mold cooling system can be at least partially blocked in the area of the adjustable small faces (4, 5).

Description

  The present invention relates to a cooled continuous casting mold for casting metal, in particular steel, having a casting size composed of two wide and narrow sides each facing each other. The wide side includes a cooling region set for maximum casting width with a cooling passage having a supply and discharge passage connected to a coolant circuit extending in a plurality of casting directions. The narrow side can be displaced to adjust to the desired casting width.

  In all slab molds (thin, medium and thick slabs), the cooling of the mold on the width side is set for maximum casting width. When casting a slab having a casting width smaller than the maximum casting width, intensive mold cooling is also effective outside the displaceable narrow side. Therefore, the cooling area is wider than the current casting width. As a result, the strands are intensively cooled even when there is no heat supply to the strands.

  As a result, on the wide side near the narrow side, a clear temperature drop is caused due to the two-dimensional heat flow. Depending on the temperature level on the wide side and the wall thickness between its working surface and the cooling passage, in this case the mold plate is made of copper material, but the immediate temperature drop on the narrow side is 200 Up to ° C or more.

  Based on such a temperature drop, no uniform dissolution conditions for the powder solvent are obtained anymore, however, these dissolution conditions are not a prerequisite for the surface quality of a good and uniform strand product. Absent.

  When the casting size is small, the same amount of water as in the case of the maximum size width is used. Therefore, in this method of use, an unnecessarily large amount of water is required. This is unnecessary for finally cooling the strands and further exacerbates the uniform dissolution of the powder solvent.

Patent Document 1 discloses a continuous strip casting mold whose narrow side is movable together with a blocking element for a cooling passage.
From Patent Document 2 , a continuous casting mold whose molding wall includes a plurality of cooling holes connected to a cooling water circuit extending from top to bottom, thereby forming a cooling region extending over the wide side. Is known. Here, in the region of the maximum temperature load of the mold, that is, in the heating zone, the passage cross-section of the cooling hole is reduced by a restrictor rod in order to increase the flow rate of cooling water and improve heat transfer. Has been proposed.
JP 09-047848 A German Patent No. 41 27 333

The problem underlying the present invention is to enable the production of slabs with different widths, in which case the working surface temperature can be adjusted uniformly for the wide side, in particular a significant temperature drop near the narrow side. It is to provide a continuous casting mold for slab sizes known from the prior art .

  This problem is solved by a continuous casting mold having the features of claim 1. Advantageous developments are described in the subclaims.

  According to the present invention, in order to adjust the cooling area depending on the casting width or the cooling water width depending on the size width, the cooling passage on the mold wide side and / or the supply and / or discharge passage is displaced on the narrow side. It is proposed that it can be at least partially or completely blocked in the region and in the casting size. Blocking can take place in the mold plate, the steel intermediate plate of the cassette mold and / or in the water cassette. The blocking can be performed in the mold supply path or the reflux path.

  Blocking should be possible between regions of the narrow side plate up to the maximum cooling width. In addition, shut-off is possible up to the maximum cooling width in a region near the narrow side where the original narrow side can be exceeded into the casting size.

  The coolant, in particular the cooling water, is blocked or significantly reduced in the narrow side region and outside the casting size, so that the temperature of the wide side work surface is made uniform in the narrow side region. Based on the uniform temperature distribution of the work surface on the wide side in the molten metal level region, the dissolution of the powder solvent and the surface quality of the cast product are improved.

  In particular, advantages are obtained when casting small casting sizes. By adapting the cooling water width depending on the size width, the coolant requirement, in particular the water requirement, can be reduced and / or the water speed can be improved. This is significant especially when the casting capacity is constant because a high water speed is possible at a high casting speed when the casting width is small. High water velocity can improve heat conduction, which can at least partially compensate for temperature rise on the work surface due to high casting speed.

  As described above, the cooling passage extending at least over the narrow displacement region can be totally or partially blocked. It is further anticipated that in order to equalize the temperature change on the wide side, the cooling passages that extend into the casting size up to 100 mm on each side in the narrow side region should also be interruptable. .

  When the degree of blocking of the coolant flow toward the mold center is reduced or the blocking of the cooling passage toward the mold center is reduced, a uniform temperature distribution on the wide working surface is obtained. This can be obtained by a corresponding blocking element tapering to the mold center in the region near the narrow side and / or within the casting size.

  The coolant is preferably water. A uniform temperature distribution is obtained when the water velocity in the region of the cooling passage which can be partially interrupted is a maximum of 25 m / s and a minimum of 0.5 m / s.

  In addition, the water speed of the cooling passage in the cooling region having the cooling passage that cannot be shut off should be a minimum speed of 0.5 m / s. This is obtained by a correspondingly set blocking element.

  In the preferred embodiment, the blockage of the individual cooling passages is obtained by a blocking element arranged on the narrow side support. This is preferably formed as a bolt that controls the supply or discharge of the individual cooling passages. The blocking element is movable with the respective narrow side or narrow side support. The desired casting size or casting width is adjusted via the narrow side. In this position, the wide side cooling passage is at least partially blocked in the vicinity of the narrow side. In this way, undesired supercooling of this region on the wide side does not occur, which advantageously affects the dissolution characteristics of the powder solvent and thereby the surface quality of the strand product.

  Further details and advantages of the invention can be seen from the subsequent claims which detail the embodiments of the invention shown in the subclaims and the figures.

  FIG. 1 shows a plan view of a continuous casting mold 1 consisting of two opposite wide sides 2, 3 and narrow sides 4, 5 between which a casting size for each slab is formed. The narrow sides 4, 5 can be displaced between the wide sides 2, 3 to adjust to a predetermined or desired casting size GFgeg or casting width. The cooling regions 6 on the wide sides 2 and 3 are set according to the maximum casting width so that the casting size having the maximum casting width can be reliably cast. The wide sides 2, 3 are provided with vertical cooling passages 7 in the form of holes which are connected to the cooling water circuit by supply passages 8 and discharge passages, respectively.

  When the casting size GFmax having the maximum casting width is cast, all the cooling passages 7 are flown by the cooling water, and the wide sides 2 and 3 are cooled over the entire cooling width 6.

  When adjusted to a casting size GFgeg having a small casting width, the cooling passage 7 or the supply passage 8 in the region 9 is at least partially blocked.

It is also shown that the influence area 9 extends beyond the original displacement area on the narrow side into the casting size. In that case, the cooling passage extending beyond the original narrow plate into the casting size is further blocked. It has been determined that partial blockage of the cooling passages may extend to a casting size up to 100 mm on each side.

  According to a preferred embodiment, at least partial blockage of the cooling passage is realized by a blocking element 10 which is fixed to the support 11 on the narrow side 4, 5 in the form of a bolt and is moved together with the narrow side. The blocking element is formed so as to taper in the direction of the mold center, and the blocking effect that decreases toward the mold center based on the tapered end 12 is exerted on the tributary of the passage.

FIG. 2 shows a side view of a mold having both narrow sides 4 and 5 and an average working surface below the melt level in a mold with and without cooling water width (13a) and (13b) according to the present invention. The figure of the temperature change of is shown. The melt level is indicated at 14 . The cooling zone 6 extends over the entire mold wide side, in which case the mold cooling can be reduced or completely shut off in conformity with the moved narrow side. If the mold cooling is reduced or blocked in the area between the maximum casting size and the narrow side 4, 5 moved, this has a positive effect on the uniform working surface temperature below the melt level, this In this case, the working surface temperature is constant up to the narrow side, whereas the working surface temperature when the influence of the present invention is not exerted on the cooling significantly decreases toward the narrow side.

FIG. 3 shows a plan view of a mold having a wide side and a narrow side with a cooling water width adapted. The side view of a casting_mold | template and the figure of the temperature change of the average working surface below the molten metal level in the casting_mold | template with and without the adaptation of a cooling water width | variety are shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Continuous casting mold 2 Wide side 3 Wide side 4 Narrow side 5 Narrow side 6 Cooling width 7 Vertical cooling passage 8 Coolant supply passage 9 Region having at least partially blocked cooling passage 10 Blocking element 11 Narrow width Side support 12 Tapered end of blocking element 13a Average working surface temperature change below melt level in mold with matching cooling water width 13b Average melt temperature below mold in mold without matching cooling water width Temperature change on the work surface 14 Molten metal level

Claims (7)

The wide side (2, 3) was set for maximum casting width with a cooling passage (7) with supply and discharge passages (8) connected to the cooling circuit, extending in a plurality of casting directions Two opposed wide sides (2, 3) with a cooling zone, the cooling passage (7) being at least partly blocked by the blocking element (10) in the region of the narrow side (4, 5) ) And a narrow continuous side (4, 5), a cooling type continuous casting mold (1) for casting metal having a casting size (GF),
The narrow side (4, 5) is displaceable in the displacement region in order to adjust to a predetermined casting size with a corresponding casting width;
As an alternative or in addition to the cooling passage (7), the supply and discharge passages (8) can also be at least partly blocked by the blocking element (10) in the displacement region , the blocking element (10) being narrow. The cooling passage and / or the supply and discharge passages are cut off so that they can be moved into the casting size beyond the width side (4, 5) and the blocking action is reduced from the narrow side into the casting size. Continuous casting mold, characterized in that it comprises an end (12) that tapers from the narrow side to the mold center so that it can be performed.   The continuous casting mold according to claim 1, wherein the blocking portion extends from the maximum cooling width to the maximum size of 100 mm and beyond the narrow width side into the casting size.   2. Continuous casting mold according to claim 1, characterized in that at least partial shut-off takes place in the mold plate, the steel intermediate plate in the cassette mold and / or the water cassette. The coolant is water, and the water velocity in the region of the cooling and / or supply and / or discharge passages which can be at least partly blocked is a maximum of 25 m / s and a minimum of 0.5 m / s The continuous casting mold according to any one of claims 1 to 3 . The continuous casting mold according to any one of claims 1 to 4 , wherein a water speed of a cooling passage in a cooling region having a cooling passage that cannot be shut off is a minimum speed of 0.5 m / s. Continuous casting mold according to claim 5 , characterized in that the blocking element (10) is movable with each narrow side (4, 5). Blocking element (10) is a continuous casting mold according to any one of claims 1-6, characterized in that fixed to the narrow side support (11) in the bolt form.

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