Continuous casting mold and method of manufacturing continuous casting mold

Abstract

To provide a mold for continuous casting which can suppress surface crack due to heterogeneity of solidification shell thickness.SOLUTION: A mold for continuous casting includes a mold cooling plate 10 which cools molten steel injected into a mold to be solidified in a continuous casting in which: plated parts 20 are spatially and periodically arranged on an internal surface of the mold cooling plate in a width direction and in a casting direction from a position 20 mm or more above a meniscus to a downward position by length calculated by the following expression (1) or more; an equivalent circle diameter of cross section of the plated part, a period in the width direction and a period in the casting direction satisfy following expressions (2)-(4) when a virtual plane at the average thickness of the plated part crosses a surface of the plated part; and R=2×Vc / 60×1000 (1), 1.0≤d≤10 (2), 0.2≤d / W≤1.0 (3), and 0.2≤d / L≤1.0 (4) where R is length mm, Vc is cast piece pulling-out speed m / min, d is the equivalent circle diameter mm, W is the period mm in the width direction, L is the period mm in the casting direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a continuous casting mold capable of suppressing surface cracks of a cast slab caused by uneven cooling of a solidified shell in the mold, and a method for manufacturing the continuous casting mold. [Background technology]

[0002] In continuous casting of steel, molten steel poured into a mold is cooled by a water-cooled mold, and the molten steel solidifies at the contact surface with the mold, forming a solidified layer (hereinafter referred to as the "solidified shell"). The solidified shell is cooled by water sprays or air-water sprays installed downstream of the mold, and is continuously drawn downwards along with the unsolidified layer inside. The cooling by the water sprays or air-water sprays solidifies the shell to the center, producing a cast slab.

[0003] Insufficient cooling in the mold reduces the thickness of the solidified shell. When support is switched to rolls downstream of the mold, the solidified shell cannot withstand the static pressure of the molten steel generated by the molten steel inside the slab. This can lead to breakouts, in which the molten steel leaks out. On the other hand, intense cooling in the mold is likely to cause uneven cooling. Uneven cooling in the mold can lead to uneven thickness of the solidified shell in the casting direction and width direction. Stresses caused by shrinkage and deformation of the solidified shell act on the solidified shell. In the early stages of solidification, these stresses concentrate in the thin-walled portions of the solidified shell, causing cracks on the surface of the solidified shell. These cracks subsequently expand due to external forces such as thermal stress and bending and straightening stresses from the rolls of the continuous casting machine, resulting in large surface cracks. Large unevenness in the solidified shell thickness can lead to vertical cracks in the mold, resulting in breakouts, in which molten steel leaks out through these vertical cracks. Cracks present in the slab will become surface defects in the subsequent rolling process, so it is necessary to treat the surface of the slab at the slab stage to remove surface cracks.

[0004] Uneven solidification in the mold is thought to occur when the carbon content is within the range of 0.08 to 0.17 mass%, particularly when the carbon content is within the range of 0.08 to 0.17 mass%. This deformation causes the solidified shell to deform due to strain caused by transformation stress resulting from volumetric shrinkage during transformation to gamma iron (austenite) via a peritectic reaction. This deformation reduces the solidification thickness of the solidified shell away from the mold inner wall, and the stress concentrates in this area, causing surface cracks. In particular, increasing the slab withdrawal speed increases the average heat flux from the solidified shell to the mold cooling water, resulting in an irregular and non-uniform distribution of heat flux, which tends to increase the occurrence of surface cracks in the slab. Specifically, in continuous slab casters with a slab thickness of 200 mm or more, surface cracks are likely to occur when the slab withdrawal speed is 1.5 m / min or higher.

[0005] In order to prevent surface cracks in the steel type that undergoes the above-mentioned peritectic reaction (hereinafter referred to as "medium carbon steel"), Patent Document 1 discloses that a mold powder with a composition that easily crystallizes is used to increase the thermal resistance of the mold powder layer and slowly cool the solidified shell. However, the slow cooling effect of the mold powder alone does not sufficiently improve uneven solidification, and surface cracks cannot be suppressed in steel types with a large amount of transformation.

[0006] Therefore, many methods have been proposed for slow cooling of the continuous casting mold itself. Patent Document 2 discloses a method for slow cooling by providing grooves or round holes in the inner wall surface of the mold to form air gaps through the grooves or round holes in order to prevent surface cracks. Furthermore, Patent Document 3 discloses a method for reducing the width of the grooves or round holes in the concave surface of the inner wall surface of the mold. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-297001 [Patent Document 2] Japanese Patent Application Publication No. 6-297103 [Patent Document 3] Japanese Patent Application Publication No. 10-296399 Summary of the Invention [Problem to be solved by the invention]

[0008] The method disclosed in Patent Document 2 has a problem in that the grooves and holes have a fine and random pitch, making it impossible to regularly and periodically distribute the heat flux, transformation stress, and thermal stress from the solidified shell to the continuous casting mold, and is therefore less effective at uniforming the solidified shell thickness.The method disclosed in Patent Document 3 has a problem in that, although the interfacial tension prevents the mold powder from flowing into the groove width or holes on the concave surface, maintaining an air gap, because the grooves are formed linearly in the casting direction, this promotes solidification delay at the relevant locations, potentially causing vertical cracks and, in severe cases, breakouts.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a continuous casting mold that can suppress surface cracks due to uneven cooling of the solidified shell in the early stage of solidification and uneven thickness of the solidified shell resulting from the transformation of δ iron to γ ​​iron in medium carbon steel, which involves a peritectic reaction, and a method for manufacturing the continuous casting mold. [Means for solving the problem]

[0010] The means for solving the above problems are as follows. [1] A continuous casting mold having a mold cooling plate that cools and solidifies molten steel poured into the mold in continuous casting, wherein plating portions are provided on the inner wall surface of the mold cooling plate from a position 20 mm or more above the meniscus to a position below the meniscus by a length calculated by the following formula (1): R=2×Vc / 60×1000 (1) 1.0≦d≦10 (2) 0.2≦d / W≦1.0 (3) 0.2≦d / L≦1.0 (4) In the above formulas (1) to (4), R is the length (mm), Vc is the slab withdrawal speed (m / min), d is the circle equivalent diameter (mm), W is the width direction period (mm), and L is the casting direction period (mm). [2] The continuous casting mold according to [1], wherein a plurality of slit grooves are provided on the outer wall surface of the mold cooling plate along the casting direction, and protrusions are provided in areas corresponding to the meniscus portions of the slit grooves. [3] The continuous casting mold according to [2], wherein the protrusions are provided at a period equal to or less than the period in the casting direction. [4] A method for manufacturing a continuous casting mold according to any one of [1] to [3], wherein the plating portion is provided on the inner wall surface of the mold cooling plate by at least one of plating means and thermal spraying means. [Effects of the Invention]

[0011] According to the present invention, the thickness of the mold powder flowing into the plating portion on the inner wall surface of the mold cooling plate varies, so that the thermal resistance of the continuous casting mold increases and decreases regularly and periodically. This homogenizes the uneven heat flux distribution caused by deformation of the solidified shell, and also distributes the generated stress, reducing the amount of strain on the solidified shell. As a result, surface cracks on the solidified shell are suppressed, and the number of surface cracks in the continuously cast slab can be reduced. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective schematic view showing a continuous casting mold according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic side view of a mold long side cooling plate that constitutes a part of a continuous casting mold, as viewed from the inner wall surface side where a plated portion is formed. [Figure 3] FIG. 3 is a schematic diagram of the AA cross section of the mold long side cooling plate. [Figure 4] FIG. 4 is an enlarged view of part B in FIG. [Figure 5]FIG. 5 is a schematic view of the CC cross section of the cooling plate on the longer sides of the mold. [Figure 6] FIG. 6 is a graph showing the relationship between d / W and the density of surface cracks. [Figure 7] FIG. 7 is a graph showing the relationship between d / L and the density of surface cracks. DETAILED DESCRIPTION OF THE INVENTION

[0013] An example of an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Fig. 1 is a schematic perspective view showing a continuous casting mold 100 according to one embodiment of the present invention. Fig. 2 is a schematic side view of a mold long side cooling plate 10 constituting a part of the continuous casting mold 100, as viewed from the inner wall surface side on which the plating portion 20 is formed. Fig. 3 is a schematic AA cross-sectional view of the mold long side cooling plate 10. Fig. 4 is an enlarged view of portion B in Fig. 3. Fig. 5 is a schematic CC cross-sectional view of the mold long side cooling plate 10.

[0014] As shown in Fig. 1, a continuous casting mold 100 for continuously casting a slab strand is configured by combining a pair of mold long side cooling plates 10 and a pair of mold narrow side cooling plates 12. The mold long side cooling plates 10 and the mold narrow side cooling plates 12 are examples of mold cooling plates included in the continuous casting mold 100. In this embodiment, the material of the mold long side cooling plates 10 and the mold narrow side cooling plates 12 may be pure copper made of 100 mass % copper, or a copper alloy containing 90 mass % or more copper with the remainder containing, for example, aluminum, chromium, zirconium, or the like.

[0015] As shown in FIG. 2, in the mold long side cooling plate 10, plating portions 20 are provided spatially periodically at regular intervals in the width direction and the casting direction on the range of the inner wall surface of the mold long side cooling plate 10 from a position at least a predetermined length U above the meniscus (molten steel surface) that is determined when steel is continuously cast to a position at least a predetermined length R below the meniscus.

[0016] The plating portions 20 are fabricated by plating, thermal spraying, laser processing, machining, etc., and are provided on the inner wall surface of the mold long side cooling plate 10 in a spatially periodic pattern in the width and casting directions of the mold long side cooling plate 10. The plating portions 20, which form the spatially periodic asperities, vary the thickness of the mold powder flowing into the asperities, thereby regularly and periodically increasing and decreasing the thermal resistance of the mold long side cooling plate 10 in the width and casting directions near the meniscus. As a result, the heat flux from the solidified shell near the meniscus, i.e., in the early solidification stage, to the continuous casting mold regularly and periodically increases and decreases. This homogenizes the non-uniform heat flux distribution caused by deformation of the solidified shell due to stress caused by the transformation of δ iron to γ ​​iron and thermal stress, and also distributes the generated stress, reducing the strain on the solidified shell and suppressing surface cracking. The plating portions 20 are formed from one metal selected from the group consisting of Ni, Cu, Cr, and Fe, or an alloy of two or more of these metals. The material of the plating portion 20 is preferably determined so that, during continuous casting, the heat transfer coefficient of the region where the plating portion 20 is provided is 75% or less or 125% or more of the heat transfer coefficient of the region where the plating portion 20 is not provided. Note that, although an example in which the shape of the plating portion 20 is conical is shown in Figures 2 to 5, the shape of the plating portion 20 is not limited to a conical shape.

[0017] Similar to the mold narrow side cooling plates 10, the mold narrow side cooling plates 12 also have plating portions 20 formed on their inner wall surfaces, and therefore a description of the mold narrow side cooling plates 12 will be omitted here. However, due to the shape of a slab, stress concentration is likely to occur in the solidified shell on the wide side surface. For this reason, surface cracks in the solidified shell are likely to occur on the wide side surface. For this reason, the mold narrow side cooling plates 12 of the continuous casting mold 100 do not need to be provided with plating portions 20.

[0018] Considering the vertical fluctuation of the meniscus during casting and its influence on initial solidification, the upper end of the area where the plating portion 20 is formed on the inner wall surface of the mold long side cooling plate 10 must be at least 20 mm above the meniscus. That is, the length U in FIG. 2 is 20 mm. Also, the lower end of the area where the plating portion 20 is formed must be at least a length R below the meniscus. Here, length R is the length calculated by the following equation (1).

[0019] R=2×Vc / 60×1000 (1) In the above formula (1), R is the length (mm), and Vc is the slab withdrawal speed (m / min).

[0020] During the period when the molten steel experiences an uneven heat flux distribution due to deformation of the solidified shell caused by stresses due to the δ / γ transformation and thermal stresses, the plating portion 20 must be provided to periodically vary the heat flux on the inner wall surface of the mold narrow side cooling plate 12. Therefore, the plating portion 20 must be provided on the inner wall surface where the molten steel is present for at least 2 seconds after the molten steel begins to solidify. Therefore, the length R shown in FIG. 2 must be at least 2 × Vc / 60 × 1000 mm. If the length R is less than 2 × Vc / 60 × 1000 mm, the effect of periodically varying the heat flux provided by the plating portion 20 becomes insufficient, resulting in insufficient suppression of surface cracks in the slab during high-speed casting or when casting medium-carbon steel, where surface cracks are likely to occur.

[0021] First, we will explain the circle-equivalent diameter d of the plated portion 20. The circle-equivalent diameter d of the plated portion 20 is evaluated as the circle-equivalent diameter of an imaginary cross section generated when an imaginary plane corresponding to the average thickness of the plated portion 20 intersects with the surface of the plated portion 20. In other words, if the dashed line shown in Figure 4 is the iso-thickness plane of the average thickness of the plated portion 20, the circle-equivalent diameter d of the plated portion 20 is d shown in Figure 4. The circle-equivalent diameter d of the plated portion 20 must satisfy the following formula (2).

[0022] 1.0≦d≦10 (2) In the above formula (2), d is the equivalent circle diameter (mm). The equivalent circle diameter d is calculated using the following formula (5).

[0023] Equivalent circle diameter d=(4×S / π) 1 / 2 ···(5) In the above formula (5), S is the area (mm ) of the imaginary cross section of the plated portion 20, which is generated when the imaginary plane of the average thickness of the plated portion 20 intersects with the surface of the plated portion 20. 2 )

[0024] If the equivalent circle diameter d of the plating portion 20 is less than 1.0 mm, the heat flux does not fluctuate, and the effect of suppressing surface cracks in the slab is insufficient. On the other hand, if the equivalent circle diameter d is greater than 10 mm, the solidification delay portion of the solidified shell becomes large, which actually increases the surface cracks in the slab. Therefore, the equivalent circle diameter d must satisfy the above formula (2).

[0025] Next, we will explain the ratio d / W of the circle equivalent diameter d to the widthwise period W of adjacent plates in the width direction that are at the same position in the casting direction. The widthwise period W is the center-to-center distance in the width direction on an imaginary cross section of the plated portion 20, which is generated when an imaginary plane on which the average thickness of the plated portion 20 intersects with the surface of the plated portion 20.

[0026] Fig. 6 is a graph showing the relationship between d / W and the surface crack density. In Fig. 6, the horizontal axis is d / W (-) and the vertical axis is the surface crack density (cracks / m 2 ) where (-) means dimensionless.

[0027] As shown in Figure 6, by setting d / W within the range of 0.2 to 1.0, the surface crack density was significantly reduced. From these results, it is believed that by setting d / W within the range of 0.2 to 1.0, the periodic heat flux distribution in the width direction was optimized to suppress non-uniform solidification, thereby suppressing surface cracking in the slab. On the other hand, when d / W exceeds 1.0, adjacent plating portions 20 partially overlap, preventing the generation of a periodic heat flux distribution in the width direction and reducing the effectiveness of suppressing non-uniform solidification. Furthermore, when d / W is less than 0.2, the heat flux period in the width direction becomes too large, resulting in delayed solidification in the slow cooling region and increasing the surface cracking in the slab. Therefore, the ratio d / W of the equivalent circle diameter d to the width direction period W must satisfy the following formula (3):

[0028] 0.2≦d / W≦1.0 (3) In the above formula (3), d is the equivalent circle diameter (mm), and W is the width direction period (mm).

[0029] Next, we will explain the ratio d / L of the circle-equivalent diameter d of the plating portion 20 to the casting direction period L of plating portions 20 that are at the same position in the width direction and adjacent to each other in the casting direction. The casting direction period L is the center-to-center distance in the casting direction on an imaginary cross section created when an imaginary plane representing the average thickness of the plating portion 20 intersects with the surface of the plating portion 20.

[0030] Fig. 7 is a graph showing the relationship between d / L and the surface crack density. In Fig. 7, the horizontal axis is d / L (-) and the vertical axis is the surface crack density (cracks / m 2 )

[0031] As shown in Figure 7, by setting d / L within the range of 0.2 to 1.0, the surface crack density was significantly reduced. From these results, it is believed that by setting d / L within the range of 0.2 to 1.0, the periodic heat flux distribution in the casting direction was optimized to suppress non-uniform solidification, thereby suppressing surface cracking in the slab. On the other hand, when d / L exceeds 1.0, adjacent plating portions 20 in the casting direction partially overlap, preventing the periodic heat flux distribution in the casting direction from being properly generated, thereby reducing the effect of suppressing non-uniform solidification. Furthermore, when d / L is less than 0.2, the heat flux period in the casting direction becomes too large, causing a significant delay in solidification in the slow cooling region and actually increasing the surface cracking in the slab. Therefore, the ratio d / L of the circle-equivalent diameter d of the plating portion 20 to the casting direction period L of the plating portion 20 must satisfy the following formula (4):

[0032] 0.2≦d / L≦1.0 (4) In the above formula (4), d is the equivalent circle diameter (mm), and L is the casting direction period (mm).

[0033] It is preferable to provide the plating portion 20 on both the mold long side cooling plate 10 and the mold narrow side cooling plate 12 of the continuous casting mold 100. However, when casting a slab having a large ratio of the slab long side length to the slab narrow side length, providing the plating portion 20 only on the mold long side cooling plate 10 is sufficient to suppress surface cracks in the solidified shell and reduce the number of surface cracks in the continuously cast slab. In addition, it is preferable that the apex of the plating portion 20 has a smooth curve such as an arc. If the apex of the plating portion 20 has a sharp shape, the mold powder and solidified shell will be restrained at that portion, which may lead to chipping of the tip of the plating portion 20.

[0034] Next, we will explain the productivity of slab casting. To improve the productivity of slab casting, it is necessary to increase the slab withdrawal speed. However, if the solidified shell is withdrawn from the mold while it is still thin, the solidified shell will lack strength, increasing the risk of breakout. Therefore, to increase the slab withdrawal speed, it is necessary to strengthen the cooling of the mold long side cooling plate 10. To strengthen the cooling, it is preferable to provide protrusions 24 in multiple slit grooves 22 provided along the casting direction on the outer wall surface of the mold long side cooling plate 10, which corresponds to the meniscus portion. By providing protrusions 24 in the multiple slit grooves 22, the heat transfer area of ​​the slit grooves 22 is increased, thereby strengthening the cooling of the mold long side cooling plate 10. Note that the term "corresponding to the meniscus portion" refers to the area from the meniscus position downward in the mold, up to the temperature (1494°C) at which the peritectic reaction of δ-γ (δ+L→δ+γ) occurs. The shape and size of the protrusions 24 may be such that, when the protrusions 24 are drawn with a resolution equivalent to the resolution (pixels / m) required to identify the shape of the slit grooves 22, the protrusions 24 cause a contracted flow in the main stream of the cooling water. Specifically, the size of the protrusions 24 in the width direction is preferably at least 1 / 3 and not more than the width of the slit grooves 22. The height of the protrusions 24 is preferably at least 1 mm from the bottom surface of the slit grooves 22 and not more than 1 / 2 the groove depth of the slit grooves 22.

[0035] Furthermore, it is more preferable to provide the protrusions 24 in the slit grooves 22 so that the installation period F of the protrusions 24 shown in FIG. 5 is equal to or less than the period L of the plating portion 20 in the casting direction, thereby increasing the critical Reynolds number of the cooling water flowing through the slit grooves 22 and making the cooling water turbulent. Here, the critical Reynolds number refers to the Reynolds number at which the water flow transitions from laminar to turbulent. This increases the heat transfer coefficient and further enhances cooling at the mold side cooling plates 10. Increasing cooling at the mold side cooling plates 10 in this way allows for an increased slab withdrawal speed without causing breakouts, thereby improving slab productivity. [Example]

[0036] This example describes continuous casting of slabs using a continuous casting mold with plating on the inner wall surface of the cooling plate on the long side of the mold, using medium carbon steel (C: 0.08-0.17% by mass, Si: 0.10-0.30% by mass, Mn: 0.50-1.20% by mass, P: 0.010-0.030% by mass, S: 0.005-0.015% by mass, Al: 0.020-0.040% by mass). The shape and period of the plating on the inner wall surface of the mold, the slab withdrawal speed Vc, and other conditions were varied during continuous casting of the slabs, and surface cracks in the slabs after casting were investigated.

[0037] A continuous casting mold having a mold long side cooling plate with a length of 900 mm from the top to the bottom, and a plating portion shown in Figures 2 to 5 provided on the inner wall surface in the range from a position 80 mm below the top end of the mold long side cooling plate to a position 300 mm below the top end, was prepared, and continuous casting of steel was carried out using this continuous casting mold.

[0038] In the examples, mold powder used had a basicity (mass % CaO / mass % SiO2) of 1.1, a solidification temperature of 1210°C, and a viscosity of 1.5 Poise at 1300°C. The superheat of the molten steel in the tundish was 25 to 35°C. The meniscus position (molten metal surface position) in the mold was 100 mm from the upper end of the mold in a steady-state pouring state, and the position of the meniscus was controlled so that the installation range of the plating unit included a range from 20 mm above the meniscus to 2 × Vc / 60 × 1000 below the meniscus.

[0039] In addition, to improve the cooling capacity of the continuous casting mold, a continuous casting mold was prepared in which the working surface of the mold was identical, but multiple protrusions were added to the slit grooves on the outer wall of the mold, so that the cooling water flowing through the slit grooves could be turbulent by raising the Reynolds number above the high critical value, and continuous casting of steel was carried out. The cooling capacity of the continuous casting mold was evaluated based on the total heat removal amount Q. The total heat removal amount Q was calculated using the following equation (6).

[0040] Q = specific heat of cooling water × cooling water flow rate × (cooling water outlet temperature – cooling water inlet temperature) (6) In the above equation (6), Q is the total heat transfer rate (MW / m 2 )

[0041] The casting conditions and evaluation results of the examples are shown in Table 1 below.

[0042] [Table 1]

[0043] Nos. 1 to 5 are casting examples in which slabs were cast by changing the surface thickness t of the plating portion as shown in Figure 4. Nos. 6 and 7 are casting examples in which the slab withdrawal speed Vc was increased and the effect of installing protrusions was confirmed. In No. 7, the protrusion installation period F was set to be less than the casting direction period L of the plating portion, causing the cooling water flowing through the slit grooves to become turbulent. This increased the heat flux from the solidified shell to the mold cooling water, making it possible to increase the total heat removal amount Q compared to No. 6.

[0044] Nos. 8 to 12 are casting examples in which the equivalent circle diameter d of the plating portion was changed to cast slabs. In No. 8, the small equivalent circle diameter d reduced the fluctuation in heat flux, and the effect of suppressing cracking of the solidified shell was not realized. As a result, surface cracks occurred in the slab in No. 8, and the crack density was high. In Nos. 11 and 12, the large equivalent circle diameter d and long casting direction period led to the development of delayed solidification zones. As a result, cracks in the solidified shell increased in Nos. 11 and 12, and surface cracks also occurred in the slab, resulting in a high crack density. On the other hand, Nos. 9 and 10 are inventive examples within the scope of the present invention, and in these casting examples, slabs with low surface crack density were cast. [Explanation of symbols]

[0045] 10 Mold long side cooling plate 12 Mold narrow side cooling plate 20 Plating section 22 Slit groove 24 protrusions 100 Continuous casting mold

Claims

1. A continuous casting mold having a mold cooling plate for cooling and solidifying molten steel poured into the mold in continuous casting, On the inner wall surface of the mold cooling plate from a position 20 mm or more above the meniscus to a position below the meniscus by a length calculated by the following formula (1), plating portions protruding from the inner wall surface are provided spatially periodically in the width direction and casting direction of the inner wall surface of the mold cooling plate, A continuous casting mold, wherein the circle-equivalent diameter, width direction period, and casting direction period of an imaginary cross section generated when an imaginary plane representing the average thickness of the plating portion intersects with the surface of the plating portion satisfy the following formulas (2) to (4): R=2×Vc / 60×1000...(1) 1.0≦d≦10 (2) 0.2≦d / W≦1.0 (3) 0.2≦d / L≦1.0 (4) In the above formulas (1) to (4), R is the length (mm), Vc is the slab withdrawal speed (m / min), d is the circle equivalent diameter (mm), W is the width direction period (mm), and L is the casting direction period (mm).

2. A plurality of slit grooves are provided on the outer wall surface of the mold cooling plate along the casting direction, 2. The continuous casting mold according to claim 1, wherein a protrusion is provided in a region corresponding to a meniscus portion of the slit groove.

3. The continuous casting mold according to claim 2 , wherein the projections are provided at a period equal to or less than the period in the casting direction.

4. A method for manufacturing a continuous casting mold according to any one of claims 1 to 3, A method for manufacturing a continuous casting mold, comprising providing the plated portion on the inner wall surface of the mold cooling plate by at least one of plating means and thermal spraying means.

Images