Copper plate having improved surface geometry
Patent Information
- Application Number
- EP2023733220
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-07-15
- Filing Date
- 2023-06-07
- Publication Date
- 2025-05-21
AI Technical Summary
Continuous casting molds experience severe wear in their narrow side walls, leading to short service life and potential defects in the metal strand due to copper diffusion, which affects productivity and quality.
A copper plate with a specific surface topography featuring a tongue-shaped and flat surface section on the hot surface side, accompanied by outer partial areas with lower levels, enhances contact behavior and reduces wear by mimicking the natural shrinkage behavior of the metallic strand, and optionally coated with wear-resistant materials for further protection.
The improved surface topography leads to reduced wear, longer service life, and higher quality products with minimized copper penetration into the strand shell, along with better control over slab geometry and reduced bulging.
Smart Images
Figure 1.1
Abstract
Description
[0001] Copper plate with improved surface geometry
[0002] The present invention relates to a narrow-sided copper plate for a continuous casting mold, in particular for use in a continuous casting mold, as well as to a continuous casting mold comprising a water box with at least one copper plate according to the invention arranged in the water box. Furthermore, the present invention relates to a method for producing the copper plate according to the invention and, in a further aspect, to a method for reconditioning a worn and / or used narrow-sided copper plate.
[0003] Continuous casting molds for the continuous casting of a metal strand from a molten metallic composition, in particular a steel strand, have long been known in the art. Such molds comprise, on the one hand, two opposing wide side walls made of copper plates with a funnel-shaped or parallel-walled pouring area extending in the casting direction to the end of the mold. Between the two wide side walls, the molds also have two narrow side walls arranged relative to one another, also made of copper plates. These narrow side walls are usually adjustable transversely to the casting direction and can be used to adjust the desired width of the metal strand.
[0004] It is known from the prior art that such narrow side walls are subject to severe wear due to their material properties, which is particularly aggravated in the area of the corners of the mold due to two-dimensional cooling and at the mold outlet due to the conical angle of the narrow side walls. This severe wear results in the narrow side walls having very short service lives and thus having to be frequently replaced with new and / or refurbished copper plates, which negatively impacts the productivity of the continuous casting plant. Furthermore, excessive wear can lead to undesired diffusion of copper into the outer layer of the metallic strand or strand shell, causing strand defects, which in turn can lead to defects on the semi-finished product during further processing.
[0005] US 4,023,612 discloses a mold that can prevent uneven wear of a narrow-sided copper plate and thus extend its service life. The narrow-sided copper plate disclosed therein comprises, on its hot surface side, an inner, convex portion surrounded by two outer, flat portions.
[0006] Another narrow-sided copper plate intended to prevent edge shell defects is known from German patent DE 2007 054 911 B4. This comprises an inner, flat section and two outer sections, each adjacent to the wide side of the narrow-sided copper plate and rising from the inner section toward the respective wide side.
[0007] Despite the solutions known from the state of the art, there is still a desire among experts to improve such narrow-sided copper plates.
[0008] Against this background, the present invention is based on the object of providing a narrow-sided copper plate for a continuous casting mold which is improved compared to the prior art, in particular to provide a copper plate which, on the one hand, has a lower tendency to wear and, on the other hand, has improved contact behavior.
[0009] Description of the invention
[0010] According to the invention, the object is achieved by a narrow-sided copper plate for a continuous casting mold having the features of patent claim 1, by a method for producing the copper plate having the features of patent claim 12 and by a method for processing a worn and / or used narrow-sided copper plate having the features of patent claim 13.
[0011] The copper plate according to the invention for a continuous casting mold, in particular for use in a continuous casting mold, comprises a plate-shaped body with a hot surface side, which is delimited by an inlet-side narrow side and an outlet-side narrow side arranged axially opposite the inlet-side narrow side, as well as a first broad side and a second broad side arranged radially opposite the first broad side; wherein the hot surface side has a first tongue-shaped and flat surface section which extends from the inlet-side narrow side of the plate-shaped body over at least part of its axial length in the direction of the outlet-side narrow side and defines a first plane;and a second surface section surrounding the first surface section, the outer partial area sections of which adjoin at least the respective broad side have a lower level than the first plane of the first tongue-shaped and flat surface section;
[0012] The inventors recognized that such a specific surface topography of the hot-surface side corresponds to the natural shrinkage behavior of a metallic strand. As a result, the strand shell within the mold conforms better to the hot-surface side of the inventive copper plate, reducing the lifting of the strand shell from individual areas of the copper plate and thus achieving improved cooling and support. Because individual areas of the copper plate are not subjected to the majority of the load, but rather the entire surface of the copper plate supports the strand shell due to the specific surface topography, a more homogeneous contact behavior is achieved across the entire hot-surface side, which significantly reduces the tendency to wear.The reduced wear leads to significantly longer service life and thus to higher-quality products, as, for example, copper penetration into the strand shell and the associated strand defects can be reduced. Furthermore, the alignment of the narrow-sided copper plates can be controlled more effectively, which further improves the slab geometry and reduces the so-called bulging of the narrow-sided copper plates.
[0013] Further advantageous embodiments of the invention are specified in the dependent claims. The features listed individually in the dependent claims can be combined with one another in a technologically expedient manner and can define further embodiments of the invention. Furthermore, the features specified in the claims are further specified and explained in the description, where further preferred embodiments of the invention are presented.
[0014] In the context of the present invention, the term "tongue-shaped" means that the width of the first surface section, which extends from the inlet-side narrow side of the plate-shaped body over at least part of its axial length toward the outlet-side narrow side, tapers. Depending on the design, the first surface section can thus comprise a trapezoidal surface section or a parabolic surface section. Both the trapezoidal surface section and the parabolic surface section can extend directly from the inlet-side narrow side toward the outlet-side narrow side.
[0015] However, in a preferred embodiment, the first surface section has a surface section defining the pouring area, which extends directly from the inlet-side narrow side toward the outlet-side narrow side over part of its axial length and whose width corresponds to that of the plate-shaped body. The first surface section therefore has a surface section defining the pouring area and a trapezoidal or parabolic surface section adjacent to the pouring area.
[0016] The axial length of the tongue-shaped and flat surface section can advantageously correspond to at least half the length of the plate-shaped body, more preferably at least 60% of the length of the plate-shaped body, even more preferably at least 70% of the length of the plate-shaped body. In a further advantageous embodiment, the axial length of the tongue-shaped and flat surface section is 50 to 100% of the length of the plate-shaped body.
[0017] The axial length of the trapezoidal or parabolic surface section adjacent to the pouring area is preferably 10 to 85% of the length of the plate-shaped body.
[0018] The second surface section, the outer partial area sections of which are at least adjacent to the respective broad side, have a lower level than the first plane of the first tongue-shaped and flat surface section, can also be designed differently.
[0019] Thus, according to one embodiment variant, the outer sub-area sections of the second surface section adjacent to the respective wide side can have a gradient extending toward the outlet-side narrow side. The gradient is preferably less than 3.0%, more preferably less than 2.0%.
[0020] In a further advantageous embodiment, the outer sub-region sections adjacent to the respective broad side can have an incline starting from the respective broad side over at least part of their radial extent. The gradient is preferably less than 3.0%, more preferably less than 2.0%.
[0021] In a further advantageous embodiment, the second surface section can have an inner sub-region section arranged between the two outer sub-region sections adjacent to the respective broad side. This inner sub-region section can be flat and have a level that is the same as the first plane of the first tongue-shaped and flat surface section. In an alternative embodiment, the inner sub-region section, starting from the outlet-side narrow side, can have a gradient over at least part of its axial extent, which is preferably less than 3.0%, more preferably less than 2.0%. Furthermore, the inner sub-region section can preferably have a gradient starting from the respective outer sub-region section, over at least part of its radial extent, which is advantageously less than 3.0%, more preferably less than 2.0%.
[0022] To further improve the service life of the narrow-sided copper plate, an advantageous embodiment provides for the hot surface side to be provided with a wear-resistant coating. Techniques known to those skilled in the art, such as electrolytic, galvanic, and / or thermal coating processes, can be used to apply the wear-resistant coating.
[0023] The wear protection coating, which may comprise one or more layers, is preferably selected from at least one of the materials comprising nickel, NiCr, Cr3C2, Ni30Cu, Ni5Al, WCCo, NiCrBSi, WCCo / NiCrBSi, Cr3C2 / NiCr, NiCrZr and / or combinations thereof.
[0024] In a first design variant, the hot surface side can be provided with a galvanic nickel coating.
[0025] In a further embodiment, the hot surface side can be coated with a galvanic nickel coating as an intermediate layer and then with a wear-resistant, hard top layer. Such an intermediate layer can also be applied electrolytically, via laser cladding, arc spraying, flame spraying (HVAF, HVOF), and / or other thermal spraying processes known to those skilled in the art at the time of application. Preferred materials for the intermediate layers are nickel, NiCr, Cr3C2 / NiCr, Ni30Cu, Ni5Al, and / or combinations thereof.
[0026] The top layer can advantageously be applied by laser deposition welding, arc spraying, flame spraying (HVAF, HVOF), and / or other thermal spraying processes known to those skilled in the art at the time of application, and / or galvanically and / or electrolytically. Preferred materials for the top layer are selected from the group comprising WCCo, NiCrBSi, WCCo / NiCrBSi, Cr3C2 / NiCr, NiCr, and / or combinations thereof.
[0027] The specific surface topography of the hot surface side has a particularly beneficial effect on the coatings mentioned and their wear, since the wear of these coatings also occurs more evenly.
[0028] In a further aspect, the present invention relates to a continuous casting mold comprising a water box and at least one narrow-sided copper plate according to the invention arranged in the water box.
[0029] Furthermore, the present invention relates to a method for producing the copper plate according to the invention, wherein firstly a plate-shaped body blank consisting of copper and / or a copper alloy is provided; then, on a hot surface side, a first tongue-shaped and flat surface section is defined, which extends from an inlet-side narrow side of the plate-shaped body blank over at least part of its axial length in the direction of an outlet-side narrow side and has a first plane; and in a second surface section surrounding the first surface section, two outer partial region sections, each adjacent to a broad side, which have a lower level than the first plane of the first tongue-shaped and flat surface section, are produced by material removal.
[0030] In a further aspect, the present invention also relates to a method for processing a worn and / or used copper plate, wherein the plate is first provided; any wear-resistant coating present is removed from a hot surface side; then, on the hot surface side, a first tongue-shaped and flat surface section is defined, which extends from an inlet-side narrow side of the plate-shaped body over at least part of its axial length in the direction of an outlet-side narrow side and has a first plane; and in a second surface section surrounding the first surface section, two outer partial region sections, each adjacent to a broad side, which have a lower level than the first plane of the first tongue-shaped and flat surface section, are created by material removal.
[0031] Any wear-resistant coating present can be removed from the copper plate, for example, chemically and / or mechanically.
[0032] Figure designation
[0033] The invention and the technical environment are explained in more detail below with reference to the figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and combine them with other components and findings from the present description and / or figures. In particular, it should be noted that the figures and in particular the illustrated proportions are only schematic. The same reference numerals denote the same objects, so that explanations from other figures can be used as a supplement if necessary. They show:
[0034] Fig. 1 shows a first embodiment of the copper plate according to the invention in a perspective view,
[0035] Fig. 2 shows a second embodiment of the copper plate according to the invention in a perspective view,
[0036] Fig. 3 shows a third embodiment of the copper plate according to the invention in a perspective view,
[0037] Fig. 4 shows a fourth embodiment of the copper plate according to the invention in a perspective view, Fig. 5 shows a fifth embodiment of the copper plate according to the invention in a perspective view, and
[0038] Fig. 6 a partial view of a continuous casting mold.
[0039] Figure 1 shows a perspective view of a first embodiment of the copper plate 1 according to the invention, which is preferably intended for use in a continuous casting mold 2 (see Figure 6). Such a copper plate 1 is formed by a plate-shaped body 3, which can be made of pure copper or alternatively of a copper alloy, such as CuCrZr, CuAg, CuZr, or another copper alloy known to the person skilled in the art at the time of the present application.
[0040] The plate-shaped body 3 has a hot surface side 4, which is bounded by an inlet-side narrow side 5, an outlet-side narrow side 6 arranged axially opposite the inlet-side narrow side 5, as well as a first broad side 7 and a second broad side 8 arranged radially opposite the first broad side 7. The edge length (L1) of each broad side 7, 8 can be, for example, 900 mm.
[0041] According to the invention, the hot surface side 4 of the narrow-sided copper plate 1 comprises a specific surface topography 9, which has a first tongue-shaped and flat surface section 10, which defines a first height level; and a second surface section 11 surrounding the first surface section 10 and having a level lower than the first height level.
[0042] The first tongue-shaped and flat surface section 10 extends from the inlet-side narrow side 5 towards the outlet-side narrow side 6 and, in the present embodiment, is formed by a trapezoidal surface section 12 and a rectangular surface section 13 that defines a pouring area. The rectangular surface section 13, which extends directly from the inlet-side narrow side 5 towards the outlet-side narrow side 6 and whose width corresponds to that of the plate-shaped body 3, has an axial length (L2) of 200 mm in the present case and, like the trapezoidal surface section 12, is flat. Accordingly, both surface sections 12, 13 have no gradient in the present embodiment.In the present example, the trapezoidal surface section 12 directly adjoining the rectangular surface section 13 has an axial length (L3) of 700 mm.
[0043] As can be seen from Figure 1, the second surface section 11 surrounding the first surface section 10 has two outer partial area sections 14, 15, each adjacent to the broad side 7, 8, which each have a lower (height) level than the first plane of the first surface section 10. Each of the two outer partial area sections 14, 15 has a gradient (G1, G2, Gn) formed in the axial direction, which extends from a side edge 16, 17 of the trapezoidal surface section 12 in the direction of the outlet-side narrow side 6. Furthermore, each of the two outer partial area sections 14, 15 has a gradient (S1, S2, Sn) formed in the radial direction, which extends from the respective broad side 7, 8 to the respective side edge 16, 17 of the trapezoidal surface section 12.
[0044] The hot surface side 4 has the lowest point with respect to the first plane of the flat first surface section 10 in this case at the corner points (P), which has a value of -1.5 mm. Accordingly, the broad side section (G0) delimited by the side edges 16, 17 and the outlet-side narrow side 6 has the greatest gradient, which then decreases continuously according to the arrows (G1, G2, Gn). The same applies to the gradient S, which has the greatest gradient at the outlet-side narrow side 6, which then decreases continuously according to the arrows (S1, S2, Sn).
[0045] It should be noted that the gradient (G) and / or the gradient (S) can be not only continuous but also stepped and / or exponential.
[0046] Figure 2 shows a perspective view of a second embodiment of the copper plate 1 according to the invention. In contrast to the embodiment shown in Figure 1, the first surface section 10 is formed by a parabolic surface section 18 and the rectangular surface section 13.
[0047] Figure 3 shows a third embodiment of the copper plate 1 according to the invention in a perspective view. In contrast to the embodiment shown in Figure 2, the second surface section 11 surrounding the first surface section 10 has an inner sub-region section 19 arranged between the two outer sub-region sections 14, 15, which in this case has a level (height) identical to the first flat surface section 10. Accordingly, the inner sub-region section 19 is flat in the embodiment shown here. The width (Ba) of the inner sub-region section 19 can correspond to 10-60% of the total width (BO) of the plate-shaped body 3, which in the embodiments shown here (Figs. 1 to 5) has a total width (BO) of 250 mm.
[0048] Figure 4 shows a fourth embodiment of the copper plate 1 according to the invention in a perspective view. In contrast to the previous embodiment (Figure 3), the parabolic section 18 has a shorter axial length (L3), which in this case is 500 mm. Furthermore, the inner partial area section 19 has a gradient (Sx) starting from the outlet-side narrow side 6, which extends to the respective side edge 16, 17 of the parabolic surface section 18. The middle narrow side section 6c arranged between the two outlet-side narrow side sections 6a, 6b therefore has neither a gradient nor a gradient. In the present embodiment, the middle narrow side section 6c has a level 0.5 mm lower than the first surface section 10.
[0049] Figure 5 shows a fourth embodiment of the copper plate 1 according to the invention in a perspective view, the inner partial region 19 of which, in contrast to the embodiment shown in Figure 4, additionally has a radially formed slope (S10, S11, S12, S1n) extending from the respective outer partial region 14, 15 in the direction of the side edges 16, 17 of the parabolic surface section 18 or in the direction of an axial center line 20. The hot surface side 4 has the lowest point with respect to the first plane of the flat first surface section 10 at the corner points (P2), which has a value of -1.5 mm. At the point (PO) intersected by the axial center line 20, the level of the hot surface side 4 corresponds to the first flat surface section 10.At the point (P1), which is located between the two outlet-side narrow-side sections 6a, 6c and 6b, 6c, respectively, the hot surface side 4 has a value of -0.5 mm in the present case. Figure 6 shows a partial view of a continuous casting mold 2 with a water box 21, in which two oppositely arranged wide-side walls 22, 23 are arranged and, between them, two mutually arranged narrow-side copper plates 1 according to the invention. In the present case, these are designed to be adjustable transversely to the casting direction.
[0050] Reference symbol
[0051] 1 copper plate
[0052] 2 continuous casting molds
[0053] 3 plate-shaped body
[0054] 4 Hot surface side
[0055] 5 inlet side narrow side
[0056] 6 outlet-side narrow side
[0057] 6a outlet-side narrow side section
[0058] 6b outlet-side narrow side section
[0059] 6c outlet-side narrow side section
[0060] 7 first broadside
[0061] 8 second broadside
[0062] 9 Surface topography
[0063] 10 first area section
[0064] 11 second area section
[0065] 12 trapezoidal surface section
[0066] 13 rectangular surface section / pouring area
[0067] 14 first (outer) section
[0068] 15 second (outer) section
[0069] 16 first page edge
[0070] 17 second side edge
[0071] 18 parabolic surface section
[0072] 19 inner sub-area section
[0073] 19a inner sub-area section
[0074] 19b inner sub-area section
[0075] 20 axial midline
[0076] 21 Water tank
[0077] 22 broad side wall
[0078] 23 Broadside wall
[0079] L1 edge length
[0080] L2 Length of surface section 13
[0081] L3 Length of area section 12 / 18
[0082] G gradient
[0083] S Slope P Corner points
Claims
Patent claims 1. A copper plate (1) for a continuous casting mold (2), in particular for use in a continuous casting mold (2), comprising: a plate-shaped body (3) with a hot surface side (4) delimited by an inlet-side narrow side (5) and an outlet-side narrow side (6) arranged axially opposite the inlet-side narrow side (5), as well as a first broad side (7) and a second broad side (8) arranged radially opposite the first broad side (7); wherein the hot surface side (4) has a first tongue-shaped and flat surface section (10) which extends from the inlet-side narrow side (5) of the plate-shaped body (3) over at least part of its axial length in the direction of the outlet-side narrow side (6) and defines a first plane;and a second surface section (11) surrounding the first surface section (10), the outer partial area sections (14, 15) of which adjoin at least the respective broad side (7, 8) have a lower level than the first plane of the first tongue-shaped and flat surface section (10); 2. Copper plate (1) according to claim 1, wherein the first surface section (10) has a trapezoidal (12) or a parabolic surface section (18).
3. Copper plate (1) according to claim 1 or 2, wherein the outer partial area sections (14, 15) of the second Surface section (11) has a gradient (G) running in the direction of the outlet-side narrow side (6).
4. Copper plate (1) according to one of the preceding claims, wherein the outer partial region sections (14, 15) adjacent to the respective broad side (7, 8) have a gradient (S) starting from the respective broad side (7, 8) over at least part of their radial extent.
5. Copper plate (1) according to one of the preceding claims, wherein the second surface section (11) has an inner section section (19) arranged between the two outer section sections (14, 15) adjacent to the respective broad side (7, 8).
6. Copper plate (1) according to claim 5, wherein the inner partial area section (19) is flat and has a level equal to the first plane of the first tongue-shaped and flat surface section (10).
7. Copper plate (1) according to claim 5, wherein the inner partial region section (19) has a gradient (S) starting from the outlet-side narrow side (6) over at least part of its axial extent.
8. Copper plate (1) according to claim 5 or 7, wherein the inner partial region section (19) has a gradient (S) starting from the respective outer partial region section (14, 15) over at least part of its radial extent.
9. Copper plate (1) according to one of the preceding claims, wherein the hot surface side (4) has a wear-resistant coating.
10. Copper plate (1) according to claim 9, wherein the wear protection coating is selected from at least one of the materials comprising nickel, NiCr, Cr3C2, Ni30Cu, Ni5Al, WCCo, NiCrBSi, WCCo / NiCrBSi, Cr3C2 / NiCr, NiCrZr and / or combinations thereof.
11. Continuous casting mold (2) comprising a water box (21) and at least one copper plate (1) arranged in the water box (21) according to one of the preceding claims.
12. Method for producing a copper plate (1) for a continuous casting mold (2), in particular for use in a continuous casting mold (2), wherein firstly a plate-shaped body blank consisting of copper and / or a copper alloy is provided; then, on a hot surface side (4), a first tongue-shaped and flat surface section (10) is applied, which extends from an inlet-side narrow side (5) of the plate-shaped body blank over at least part of its axial length in extending in the direction of an outlet-side narrow side (6) and having a first plane; and in a second surface section (11) surrounding the first surface section (10), two outer partial areas (14, 15) are created by material removal, each adjacent to the respective broad side (7, 8), which have a lower level than the first plane of the first tongue-shaped and flat surface section (10). Method for reconditioning a worn and / or used copper plate (I), wherein this is first provided; any wear protection coating present is removed from a hot surface side (4); on the hot surface side (4) then a first tongue-shaped and flat surface section (10) is defined, which extends from an inlet-side narrow side (5) of the plate-shaped body (3) over at least part of its axial length in the direction of an outlet-side narrow side (6) and has a first plane; and into a second surface section surrounding the first surface section (10) (II) by material removal, two outer partial region sections (14, 15) are produced, each adjacent to the respective broad side (7, 8), which have a lower level than the first plane of the first tongue-shaped and flat surface section (10). Method according to claim 12 or 13, wherein a wear-resistant coating is applied to the hot surface side (4) having the two surface sections (10, 11) by means of an electrolytic, a galvanic and / or a thermal coating process. Method according to claim 14, wherein the wear-resistant coating is selected from at least one of the materials comprising nickel, NiCr, CraC2, Ni30Cu, Ni5Al, WCCo, NiCrBSi, WCCo / NiCrBSi, Cr3C2 / NiCr, NiCrZr and / or combinations thereof.