KR20120080224A - Continuous casting die - Google Patents

Abstract

The present invention relates to a continuous casting die for continuously casting a metal strand having light side walls (1) and narrow side walls (2) displaceably disposed between the light side walls (1), in which case the light side walls And the narrowing walls 2 jointly form a forming cavity 3 from the die inlet edge 4 to the die outlet edge 5 to receive the metal melt and form the metal strands. Each buccal wall (2) is divided into three buccal wall regions (6) from the die inlet edge (4) to the die outlet edge (5), and the continuous heat dissipation and Edge rotation is achieved in the transition regions. The goal is achieved by the forming cavity having a convex contour 11 in the central region 6a of each buccal wall 2 at the die inlet edge 4, the convex contour 11 being a straight line. To the die outlet edge 5 at the point of continuous transition to the contour 12 or to the convex contour 15 with a smaller curvature than at the die inlet edge 4.

Description

Continuous Casting Dies {CONTINUOUS CASTING DIE}

The present invention relates to a continuous casting die for continuously casting metal strands according to the preamble of the present claim 1.

In particular, the present invention relates to a continuous casting die for continuous casting of steel strands having slab cross sections, thin-slab cross sections or strip cross sections. In this case the wide side walls of the die may be formed on the side of the planar plate forming the forming cavity, but will also have a funnel-shaped extension over at least one partial region of its longitudinal extension. And, along with the narrow side walls, form a funnel die for thin slab casting.

Continuous casting dies of the type according to the invention are already known in a number of publications, for example KR 2004-0058588 A, DE 1508802 A1 or WO 99/12675 A1.

These continuous casting dies described in many publications have light side walls and narrow side walls displaceably disposed between the light side walls, in which case the light side walls and narrow side walls receive metal melts and form metal strands. To form a cavity formed from the die inlet edge to the die outlet edge. Continuous casting dies of this type allow for varying the individual widths of the cross sectional dimensions of the metal strands to be cast during the continuous casting operation, and in some cases also allowing replacement of the thickness of the metal strands to be cast if the structural shapes match. Each buccal wall is divided into three buccal wall regions from the die inlet edge to the die outlet edge, which include one central region and edge regions connected to both sides of the central region. The edge regions of the buccal wall have lateral region surfaces inclined towards the forming cavity starting from a separate contact line with an adjacent central region. Thereby a molding cavity with cut-off edges or phases is obtained inside the die, which in this way is known in the context of strand hardening in the edge region or corner region of the continuous casting die. The problem, namely the lifting of the strands in this region and the irregular cooling associated with the region, and the resulting edge and longitudinal crack formations, are reduced, but not completely solved.

In addition, buccal walls formed by continuous planar walls are a common prior art. An implementation of this manner is likewise described in KR 2004-0058588 A.

The object of the present invention is to further reduce the above described disadvantages of the known prior art, and to ensure that sufficient and evenly good heat dissipation in the buccal wall edge areas is achieved from the central area of the buccal wall to adjacent edge areas. In the zone, it is proposed a continuous casting die having light sidewalls and buccal walls, which is ensured by forming a metal strand to be formed or a strand shell of the strand.

According to the invention, the problem is solved by the features of claim 1. The above problem is solved by the forming cavity from the center region of each buccal wall at the die inlet edge, to a straight contour or at a continuous transition point to a convex contour with a smaller curvature than at the die inlet edge to the die outlet edge. This is done in a manner with a convex outline that follows.

By the special shape of the contours of the buccal wall central region from the die inlet edge to the die outlet edge, by the continuous reduction of the convex bulging of the forming cavity, the strand shell chamfers the inclined side region surfaces. Pressing harder inward, where locally reduced heat dissipation is increased, thereby preventing gap formation between the strand shell and the die wall, and increasing operational stability. Continuous normal planes about the die longitudinal axis from the die inlet edge to the die outlet edge underlie this consideration.

According to one preferred design of the invention, the length of the convex contour of the buccal wall center region at the die inlet edge is longer than the contour length of the buccal wall central region at the die outlet edge. The resulting continuous reduction in contour length in distance from the die inlet edge to the die outlet edge allows the shrinkage of the strand shell to better follow the strand shell path through and from the die, At the same time, the strand shell pressurization to the inclined side region surface can be maintained at a predetermined and desired compression force range.

As the curvature increases or decreases constantly, the convex contour of the buccal wall central region at the die inlet edge is formed as an arc, or a curve extending symmetrically with respect to the die center plane across the die center plane. One preferred design of the area is obtained, in which case the curvature of the convex contour in the continuous planes about the die longitudinal axis decreases uniformly from the die inlet edge to the die outlet edge.

The convex contour of the buccal wall center region at the die inlet edge is formed into an arc and the curvature of the arc in constant planes about the die longitudinal axis is constantly reduced to reach a value of zero at the die outlet edge. If the contour forms a straight line, one preferred implementation is obtained. Thereby, not only the advantages of the manufacturing technology aspects but also the balance when pressing the strand shell into the edge regions of the buccal walls are obtained.

However, the contours in the buccal wall central region may be different mathematics such as, for example, an ellipse, parabola, trigonometric function, or other function using symmetric profiles about the reference axis, more specifically symmetric profiles crossing the die center plane. Inference can also be made uniformly from functions.

According to one preferred embodiment of the invention, the contact lines of the central region and the side regions are aligned along the light side walls in parallel with the light side walls in the displacement region of the buccal walls. In a typical embodiment, the two narrow side walls and the two light side walls both form casting cones so that the contact lines are oriented in a warped direction with respect to the die longitudinal axis.

According to one further design of the invention, as the curvature increases or decreases constantly, the contours of the buccal wall regions of the buccal wall at the die inlet edge are formed in a straight line or a curve symmetrically extending about the arc or die center plane. It is. The contact lines of the buccal wall regions of the buccal wall at the die outlet edge are formed in a straight line.

According to one preferred embodiment, the contour is formed straight at the die outlet edge as well as at the die inlet edge. Even in the transition region from the die inlet edge to the die outlet edge, the contour always forms a straight line in all legal planes.

If the contours formed in straight lines at the edge regions of the buccal wall form a diffusion angle greater than 90 ° in each legal plane lying towards the die longitudinal axis, the inclination of the buccal wall edge regions is 2 from the central region to the adjacent edge regions. Results in active edge rotation of the strand cells in two transition zones. The further the diffusion angle progresses towards 180 °, the less the pressure of the strand shell against the edge regions, achieved by the special contouring of the central region. For this reason, the diffusion angle effective for solving the said subject is 90 degrees-150 degrees. Optimum conditions are obtained when the diffusion angle ranges from 110 ° to 140 °.

In one preferred refinement of the invention, the inclined side region surface of the buccal wall edge region is formed in such a way that it crosses in the forming cavity direction starting from the contact line between the central region and the edge region. Thus, the edge rotation of the strand shells formed in the die can also be induced in the transition zone from the edge region of the buccal wall to the light side wall.

The horizontal spacing of the contours of the buccal walls facing each other in the normal plane to the die longitudinal axis passing through the forming cavity of the continuous casting die is constantly reduced from the die inlet edge to the die outlet edge, thereby providing overall cooling conditions and structure. Contraction depends on the transformation. In this way, strand shell pressurization balance to the edge regions of the buccal walls can also be achieved.

Further advantages and features of the invention are set forth in the following description of non-limiting embodiments, in which case reference is made to the following figures:
1 is a continuous casting die with light sidewalls and buccal sidewalls according to the prior art shown in three views,
2 is two implementations of a continuous casting die with buccal walls in accordance with the present invention;
3 are further implementations of a continuous casting die with buccal walls in accordance with the present invention.

1 shows two designs and three design diagrams in which a continuous casting die for continuous casting of steel strands in a continuous casting installation, but overall also suitable for casting other metal strands, can be attributed to the basic structure and the prior art. It is shown schematically. The top view shows the cross-sectional shape, here the slab cross section, the front view follows the cutting line A-A of the top view, and the cross-sectional view follows the cutting line B-B of the top view.

The continuous casting die has two narrow side walls 2 displaceably disposed between the two light side walls 1 and the two light side walls (within the adjustment range by means of adjustment devices not shown in detail in the drawing). Include. During the casting operation, the narrow side walls between the light side walls are arranged in a fixed state. The two light side walls 1 and two narrow side walls 2 together form a forming cavity 3 for receiving metal melts and forming metal strands. The forming cavity extends from the die inlet edge 4 to the die outlet edge 5. In this figure, inclined buccal wall alignment is typically omitted in order to implement a casting cone along the width. The inner contour of the buccal wall 2 is symmetrically formed with respect to the die center plane E, which extends parallel to the light side wall 1 and comprises a die longitudinal axis 8. . In the front view of FIG. 1, the bath level of the metal melt that will flow continuously and the slowly formed and thickened strand shell below it are shown in broken lines.

Each buccal wall 2 is divided into three buccal wall regions 6, i.e. one central region 6a and both sides of the central region, from the die inlet edge 4 to the die outlet edge 5. It is divided into edge regions 6b which are laterally connected. Contact lines 7 forming at least edges in the buccal wall 2 and aligned parallel to the light side wall separate the central central area 6a from the two lateral areas 6b. Fillets can minimize the edge effect on the contact lines 7.

Two implementations of known buccal walls are shown in the top view of FIG. 1, which implements this basic principle, but with the disadvantages described in the introduction with respect to the valuation of the prior art. In the upper half of the top view of FIG. 1, the buccal wall 2 is formed by an image plane with respect to the die longitudinal axis 8, or a central region 6a formed by a straight line 9 in an arbitrarily selected legal plane N. ), And thus the central region 6a forms a plane. A side region 6b is connected to the central region 6a and the surfaces of the side region appear structurally inclined with respect to the central region. Correspondingly, the forming cavity 3 has cut-off edges. According to one further implementation of the prior art shown in the lower half of the top view of FIG. 1, the central region 6a expands concave to form a recess 10 into the forming cavity 3. In the same manner as the first implementation already described, the side region 6b is connected to the central region. In both implementations, optimal heat transfer in the transition region from the buccal wall to the light side wall is not solved, as detailed above in the introduction to the prior art valuation.

FIG. 2 shows, in plan view, two implementations of a continuous casting die with narrowing walls 2 according to the invention, one at a time between the two light side walls 1, taking into account the casting cone. Correspondingly, the bogies include a die outlet edge as well as a profile of the die inlet edge 4 in the buccal wall 2 in the space between the die inlet edge 4 and the two light side walls 1. 5) and with it the contour profile of the die outlet edge at the buccal wall 2 in the space between the two light side walls 1 is also shown.

Each buccal wall 2 is divided into three buccal wall regions 6 from the die inlet edge 4 to the die outlet edge 5. The forming cavity in the central region 6a of the buccal wall 2 has a convex contour 11 at the die inlet edge 4, which is a straight line which gives shape to the metal strand which is continuously out of the continuous casting die. It leads to the die outlet edge 5 at a continuous transition point to the contour 12. The two edge regions 6b connected to both sides of the central region 6a start from the contact lines 7 connecting the die inlet edge 4 to the die outlet edge 5 and limiting the central region. The inclined side region surfaces 13 are inclined. The contact lines 7 lie in a plane parallel to the light side wall 1. On the die inlet edge 4, on the die outlet edge 5 and in the region between the two edges, straight lines 4 occur in each legal plane about the die longitudinal axis 8. From these straight lines 14 of the edge regions 6b the result is a diffusion angle γ always greater than 90 ° in all the normal planes with respect to the die longitudinal axis. However, the diffusion angle should not exceed 150 ° because the relatively larger diffusion angle results in less and less effect of optimal heat dissipation and the edge rotation of the strand shell on which the present invention is based. to be.

2 likewise shows that the length of the convex contour 11 of the central region 6a of the buccal wall 2 at the die inlet edge 4 is longer than the straight contour 12 at the die outlet edge 5. This results in an optimal value for uniformly pressing the local strand shell into the side region surfaces from the selected total contouring of the selected diffusion angle γ of the central region and the inclined side region surfaces 13. Obtained.

The horizontal spacings of the contours 11, 12 of the buccal walls 2 facing each other in the legal plane N with respect to the die longitudinal axis 8 penetrating the forming cavity 3 of the die are defined by the die inlet edge ( From 4) continuously over the die outlet edge 5.

In the first implementation shown in the upper half of FIG. 2, straight lines 14 extend from the contact line 7 to the light side walls 1. In the second implementation shown in the lower half of FIG. 2, straight lines 14 have been chamfered in the direction of the buccal wall 2, resulting in chamfers 17. By chamfering the edge region 6b, the maximum temperature occurring in the buccal wall 2 can be reduced.

According to two implementations of the buccal walls 2 according to the invention of the continuous casting die, shown in FIG. 3, the forming cavity has a convex contour 11 in the central region 6a at the die inlet edge 4. The contour 11 leads to the die outlet edge 5 at the point of continuous transition to the similarly convex contour 15 with a smaller curvature than at the die inlet edge 4. Likewise according to one very preferred implementation shown in FIG. 3, the convex contours 11, 15 can be formed with circular arcs, in which case the arc R 16 at the die outlet edge 5. This is larger than the radius R1 of the arc 16 at the die inlet edge 4.

3 shows that the inclined side region surfaces 13 of the edges 6b of the buccal wall 2 are formed in such a way that they start from the contact lines 7 and cross in the direction of the forming cavity 3. We show two further implementations of the invention which improve the rotation of the strand cell in the transition region between the central region and the edge region, but likewise between the edge region and the adjacent light side wall. This implementation is illustrated by the different relative positions of the straight lines 14 at the die inlet edge 4 and the die outlet edge 5.

In the first implementation shown in the upper half of FIG. 3, the straight lines 14 extend from the contact line 7 to the light side walls 1. In the second implementation shown in the lower half of FIG. 3, the straight lines 14 of the buccal wall 2 in the light side wall region are rounded, resulting in radii 18. By rounding the edge region 6b, the maximum temperature occurring in the buccal wall 2 can be reduced.

1: light side wall 2: buccal wall
3: forming cavity 4: die inlet edge
5: die outlet edge 6: buccal wall regions
6a: center region 6b: edge region
7: contact line 8: die longitudinal axis
9: straight line 10: concave
11: Convex Contour 12: Straight Contour
13: inclined side area surface 14: straight
15: Convex contour 16: arc
17: Chamfer 18: Radius
E: die center plane
N: legal plane about the die longitudinal axis 8
R1, R2: radius of arc 16
γ: diffusion angle

Claims (9)

A continuous casting die for continuously casting metal strands having light side walls 1 and narrow side walls 2 displaceably disposed between the light side walls 1,
The light side walls 1 and the narrow side walls 2 are connected to a die outlet edge 5 from a die inlet edge 4 to receive a metal melt and form a metal strand. Forming cavities 3 leading up to the cavity are formed jointly, and each buccal wall 2 is divided into three buccal wall regions 6 extending from the die inlet edge 4 to the die outlet edge 5. The three buccal wall regions include one central region 6a and edge regions 6b connected to both sides of the central region, and the edge regions 6b are the central region 6a. Has lateral area surfaces 13 starting from each contact line 7 with) and inclined toward the forming cavity 3,
The forming cavity 3 has a convex contour 11 in the central region 6a of each buccal wall 2 at the die inlet edge 4, which contour 11 is a straight contour 12. Or to the die outlet edge 5 at a continuous transition point to a convex contour 15 having a smaller curvature than at the die inlet edge 4,
Continuous die casting. The method of claim 1,
The length of the convex contour 11 of the central region 6a of the buccal wall 2 at the die inlet edge 4 is the length of the central region 6a of the buccal wall 2 at the die outlet edge 5. Characterized in that it is longer than the length of the contours 12, 15,
Continuous die casting. The method according to claim 1 or 2,
As the curvature constantly increases or decreases, the convex contour 11 of the central region 6a of the buccal wall 2 at the die inlet edge 4 is reduced to the arc 16 or the die center plane E. Intersecting and formed symmetrically with respect to the die center plane, the curvature of the convex contour at normal planes N contiguous with respect to the die longitudinal axis 8 is defined by the die inlet edge ( Characterized by a constant decrease across the die outlet edge 5 from 4),
Continuous die casting. The method according to any one of claims 1 to 3,
The contact lines 7 of the central region 6a and the side regions 6b are parallel to the light side walls 1 in the displacement region of the narrow side walls 1. Characterized in that aligned along,
Continuous die casting. The method according to any one of claims 1 to 4,
As the curvature constantly increases or decreases, the contour 11 of the regions 6b of the buccal wall 2 at the die inlet edge 4 is a straight line 14 or an arc or the die center plane E Characterized in that formed in a curve extending symmetrically with respect to,
Continuous die casting. 6. The method according to any one of claims 1 to 5,
Characterized in that the contour 11 of the regions 6b of the buccal wall 2 at the die outlet edge 5 is formed by a straight line 14,
Continuous die casting. 7. The method according to any one of claims 1 to 6,
In the edge regions 6b of the buccal wall 2, the contours 11 formed by straight lines 14 are larger than 90 ° in each legal plane N lying towards the die longitudinal axis. To form, preferably characterized in that the diffusion angle is in the range of 110 ° to 140 °,
Continuous die casting. The method according to any one of claims 1 to 7,
The inclined side region surface 13 of the edge region 6b of the buccal wall 2 starts from the contact line 7 between the central region 6a and the edge region 6b in the direction of the forming cavity 3. Characterized in that it is formed in a way that crosses,
Continuous die casting. The method according to any one of claims 1 to 8,
Horizontal gaps of the contours 11 of the narrowing walls 2 facing each other in the normal plane N with respect to the die longitudinal axis 8 passing through the forming cavity 3 of the continuous casting die are introduced into the die. Characterized by a constant decrease from the minor edge 4 over the die outlet edge 5,
Continuous die casting.

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