KR100665531B1 - The Continuous Casting Mold - Google Patents

Abstract

In the present invention, a cooling water jacket is provided, and in a continuous casting mold made of copper (Cu) or copper alloy, a high-speed flame of nickel (Ni) -chromium (Cr) alloy is formed on an inner surface of an injection hollow portion of the continuous casting mold 100. The alloy layer 144 is formed by spraying by thermal spraying (HVOF) and finishing with vacuum heat treatment, or a nickel (Ni) -chromium (Cr) alloy is formed at the lower half of the inner surface of the injection hollow of the continuous casting mold 100. The alloy layer 144 sprayed by the thermal spraying method (HVOF) is formed, and the plating layer 144 'is formed on the upper half by electroplating using any one of chromium (Cr), nickel (Ni), and nickel alloy. In the upper half of the alloy layer 144 or the plating layer 144 ′, magnesia (MgO), zirconia (ZrO ₂ ), yttria (Y ₂ O ₃ ), chromia (Cr ₂ O ₃ ), and alumina (Al ₂₎ O ₃ ), titania (TiO ₂ ) using at least one of the coating layer (146,146 ') is characterized in that the coating by the plasma spraying method (146,146') is formed. According to such a structure, there exists an advantage that the crack prevention and abrasion resistance formed in the surface of the continuous casting mold are improved significantly.

Continuous casting mold, long side, short side, alloy layer, plating layer, coating layer, coating layer

Description

Continuous Casting Mold {The Continuous Casting Mold}

1 is a schematic diagram of a device in which a general continuous casting process is performed to continuously cast molten steel to produce a slab.

Figure 2 is a state diagram showing after the continuous casting process of a typical continuous casting mold.

3 is a structure photograph of a plasma spray coating layer using a nickel (Ni) -based magnetic soluble alloy.

Figure 4 is a photograph of the structure after the heat-treated plasma spray coating layer of a nickel (Ni) -based magnetic soluble alloy.

5 is a schematic configuration diagram of a continuous casting mold according to the present invention.

Figure 6 is a process flow diagram showing the process of forming an alloy layer in a continuous casting mold of the present invention.

7 is a cross-sectional view showing a state in which an alloy layer and a coating layer are formed in the continuous casting mold of the present invention.

8 is a process flow diagram showing a process of forming an alloy layer and a plating layer in a continuous casting mold of the present invention.

9 is a cross-sectional view showing a state in which an alloy layer, a plating layer and a coating layer are formed in the continuous casting mold of the present invention.

10 is a structure photograph of an alloy layer formed by a high-speed flame spraying method (HVOF) by a nickel (Ni) -chromium (Cr) alloy.

FIG. 11 is a texture photograph of an alloy layer formed by a high-speed flame spray method (HVOF) using a nickel (Ni) -chromium (Cr) alloy after heat treatment in an atmosphere furnace. FIG.

FIG. 12 is a texture photograph of an alloy layer formed by a high speed flame spraying method (HVOF) by a nickel (Ni) -chromium (Cr) alloy after heat treatment in a vacuum furnace. FIG.

Explanation of symbols on the main parts of the drawings

100. Mold for continuous casting 120. Long side mold

122,142. Meniscus section 140. Short side type

144. Alloy layer 144 '. Plated layer

146,146 '. Coating layer 148,148 '. Coating layer

S11, S21. Washing process S12, S22. Pretreatment process

S13,23. Thermal spraying processes S14, S24. Heat treatment process

S15, S26. Post-Processing Process S25. Plating process

The present invention relates to a continuous casting mold, and more particularly, the inner surface of the injection hollow portion of the continuous casting mold is plated by a high-temperature flame spraying method (HOVF) using a nickel (Ni) -chromium (Cr) alloy and subjected to vacuum heat treatment. In the lower half of the inner surface of the injection hollow portion of the alloy layer or continuous casting mold formed by finishing, an alloy layer sprayed by a high speed flame method (HOVF) is formed by using a nickel (Ni) -chromium (Cr) alloy, and in the upper half, chromium (Cr) ), Nickel (Ni), and nickel alloys, the present invention relates to a continuous casting mold in which a plating layer formed by plating by an electroplating method is formed.

Recently, the continuous casting technology of steel has been developed, and the performance ratio for steel production is rapidly increasing. Accordingly, the continuous casting operation has developed the speed of casting speed and the width changing technology at the time of casting.

In addition to these trends, the molds used in continuous casting are gradually used in harsh conditions, and in particular, damages are caused by wear and corrosion at the lower end, requiring frequent maintenance and replacement.

Figure 1 shows a schematic diagram of a device in which a general continuous casting process for producing a slab by continuously casting molten steel, such as high carbon steel, low carbon steel, stainless steel, special steel.

As shown in the drawing, the manufacturing process of the slab is the molten steel (5) is melted in the blast furnace is contained in the ladle (Ladle, 1) temporarily stored and then moved and poured in the tundish (3), the tundish In (3), the molten steel 5 is moved into the continuous casting mold 10 to be initially solidified to a predetermined shape and cooled while being moved to a strand 7, which is formed in a long rail shape, to be cooled into a slab 9. .

Here, the continuous casting mold 10 serves to make a constant shape while cooling the surface of the molten steel 5, which is a high temperature, and as shown in FIG. It consists of a short side mold 14 which is shorter in length than the long side mold 12.

The long side mold 12 and the short side mold 14 are made of copper (Cu) or copper alloy excellent in heat transfer rate, each inner surface is installed to be in contact with the hot molten steel (5), the outer surface of the molten steel (5) Cooling water jacket (not shown) that cools the inner surface heated by the high temperature is provided is provided.

Therefore, the molten steel 5 accommodated in the long side mold 12 and the short side mold 14 is cooled by the cooling water jacket and solidified while moving toward the bottom side of the long side mold 12 and the short side mold 14, thereby continuously casting. Is done.

However, the prior art as described above has the following problems.

That is, heat cracks due to heat shock by the hot molten steel 5 are applied to the meniscus portions 12a and 14a in which air and molten steel 5 are in contact with upper ends of the long side mold 12 and the short side strain 14. Crack) occurs, and the long side mold 12 and the short side mold 14 have a structure in which a passage becomes narrower as it goes downward, so that the pressure and the slag solidify the pressure applied from the cooled slab at the lower end thereof, thereby increasing the slab hardness. Etc., damage parts 12b and 14b due to severe wear and corrosion are generated.

Therefore, there is a problem that the frequent repair and replacement of the long side mold 12 and the short side mold 14 during the continuous casting operation.

Accordingly, efforts have been made to improve productivity and product quality by extending the life of the continuous casting mold 10 by coating the inner surfaces of the long side mold 12 and the short side mold 14.

Although the surface of the long side mold 12 and the cross-section mold 14, which is the continuous casting mold 10, was initially coated with high hardness chromium (Cr), the long side made of copper (Cu) plate. The difference in coefficient of thermal expansion between the mold (12) and the short side mold (14) and chromium (Cr) plating is large, so that it is easily peeled off.Then, after applying nickel (Ni) plating, the service life is slightly extended, but the wear resistance is weak. have.

Due to such a limitation of the peeling of the plating and the wear resistance, the plasma spraying method using a soluble alloy has recently been adopted (Japanese Patent Application No. 57-7360), and the life of the continuous casting mold 10 has been greatly improved. In the case of plasma spray coating using the alloy, many small pores are generated in the thermal spray coating layer as shown in FIG. 3, and when the thermal spraying is performed in a general atmosphere after the plasma spray coating, the thermal spray coating layer is shown in FIG. 4. Small pores aggregate in the tissue to coarse to form large pores, and the hardness of the thermal spray coating layer is also lowered, which adversely affects wear resistance.

In the case of thermal spray coating using a magnetic alloy, the heat transfer coefficient of the thermal spray coating layer is not only lower than that of the copper plate, which is the base material of the nickel plating layer or the continuous casting mold 10, but also has a low melting point. In addition, there may be disadvantages in that heat cracks may be generated due to heat effects from the molten steel 5 or a chemical reaction between the molten steel 5 and the thermal spray coating layer.

An object of the present invention for solving the above problems is, by using a nickel (Ni) -chromium (Cr) alloy on the inner surface of the injection hollow portion of the continuous casting mold plated by a high speed flame spraying method (HOVF) to finish by vacuum heat treatment This is to provide a continuous casting mold in which the alloy layer is formed.

Another object of the present invention, an alloy layer which is sprayed by high-speed flame spraying (HOVF) using a nickel (Ni) -chromium (Cr) alloy is formed in the lower half of the inner surface of the injection hollow portion of the continuous casting mold, The present invention provides a continuous casting mold in which a plating layer is formed by plating by electroplating using any one of (Cr), nickel (Ni), and nickel alloy.

Continuous casting mold according to the present invention for achieving the object as described above, in the continuous casting mold made of copper (Cu) or copper alloy provided with a cooling water jacket, the inner surface of the injection hollow portion of the continuous casting mold The alloy layer is formed by spraying a nickel (Ni) -chromium (Cr) alloy with a high-speed flame spraying method (HVOF) and finishing with vacuum heat treatment, wherein the alloy layer of the nickel (Ni) -chromium (Cr) alloy is weight percent. Low chromium (Cr) 7.5 to 17%, boron (B) 1.6 to 4.2%, silicon (Si) 3.5 to 4.5%, carbon (C) 0.25 to 0.9%, iron (Fe) 0.25 to 4.2% It is characterized by consisting of nickel (Ni) and other unavoidable impurities.

On the upper outer surface of the alloy layer, magnesia (MgO), zirconia (ZrO ₂ ), yttria (Y ₂ O ₃ ), chromia (Cr ₂ O ₃ ), alumina (Al ₂ O ₃ ), titania (TiO ₂ ) It is characterized in that the coating layer is coated by a plasma (Plasma) spraying method using at least one of the.

In addition, the present invention is provided with a cooling water jacket, in the continuous casting mold made of copper (Cu) or copper alloy, on the inner surface of the injection hollow portion of the continuous casting mold, chromium (Cr) 7.5 to 17% by weight, boron (B) 1.6 to 4.2%, silicon (Si) 3.5 to 4.5%, carbon (C) 0.25 to 0.9%, iron (Fe) 0.25 to 4.2% and the balance consists of nickel (Ni) and other unavoidable impurities An electroplating method using an alloy layer in which a nickel (Ni) -chromium (Cr) alloy is sprayed by a high-speed flame spraying method (HVOF) and chromium (Cr), nickel (Ni), or nickel alloy on the upper side of the alloy layer. It is characterized in that the plating layer is plated with.

On one side of the outer surface of the plating layer, magnesia (MgO), zirconia (ZrO ₂ ), yttria (Y ₂ O ₃ ), chromia (Cr ₂ O ₃ ), alumina (Al ₂ O ₃ ), titania (TiO ₂ ) It is characterized in that the coating layer which is coated by the plasma (Plasma) spray method using at least one.

Boron nitride (BN) is further applied to the coating layer.

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According to the present invention having such a configuration, there is an advantage that the crack prevention and abrasion resistance formed on the surface of the continuous casting mold are remarkably improved.

Hereinafter, with reference to the accompanying drawings a preferred embodiment of the continuous casting mold according to the present invention will be described in detail.

5 is a schematic configuration diagram of a continuous casting mold according to the present invention.

As shown in the drawing, the continuous casting mold 100 is a mold used in a process of manufacturing slab, and molten steel melted in a blast furnace is temporarily contained in a ladle. After being stored and moved and poured into the tundish, the molten steel is moved in the tundish, thereby cooling the surface of the hot molten steel to form a certain shape.

As shown in FIG. 5, the continuous casting mold 100 includes a long side mold 120 having a relatively long length and a short side mold 140 having a shorter length than the long side mold 120.

The long side mold 120 and the short side mold 140 is made of copper (Cu) or copper alloy with excellent heat transfer rate, each inner surface is installed to be in contact with the hot molten steel, the outer surface is heated by the high temperature of the molten steel Cooling water jacket (not shown) is provided to cool the.

Therefore, molten steel accommodated in the long side mold 120 and the short side mold 140 is cooled by the cooling water jacket and solidified while moving toward the bottom side of the long side mold 120 and the short side mold 140, thereby making continuous casting.

6 is a process flow chart showing a process of forming an alloy layer in the continuous casting mold of the present invention, Figure 7 is a cross-sectional view showing a state in which the alloy layer and the coating layer is formed in the continuous casting mold of the present invention. have.

As shown in the drawing, the process of forming the alloy layer 144 of the continuous casting mold 100 is a washing step (S11) for cleaning the surface on which the alloy layer 144 is formed, and after the washing step (S11) Pretreatment step (S12) to form a surface roughness in the continuous casting mold (100), and after the pretreatment step (S12) nickel (Ni)-chromium (Cr) alloy is sprayed by a high-speed flame spraying method (HVOF) alloy layer A thermal spraying step (S13) for forming a (144), and a heat treatment step (S14) and the like performed in a vacuum furnace to increase the density and hardness of the alloy layer 144 after the thermal spraying step (S13).

Since the continuous casting mold 100 includes a long side mold 120 and a short side mold 140 as shown in FIG. 5, all of them can be applied, but in the present invention, the short side mold 140 is used as an embodiment. Let's explain.

The washing step (S11) is to remove the oil component harmful to the adhesive strength of the short strain mold 140 and the alloy layer 144 by remaining on the surface of the short strain mold 140, the alloy layer 144 with a cloth acetone. To clean the surface of the short side strain 140 to form a).

The pretreatment step (S12) is performed to improve the adhesive force with the alloy layer 144 after the surface cleaning of the short side mold 140 is finished, aluminum oxide grit having a particle size of 24 ~ 80 mesh (Mesh) By performing short blasting with compressed air using a to ensure that the surface roughness is formed on the short side deformation (140).

After the pretreatment step (S12) is performed, a spraying step (S13) for forming the alloy layer 144 directly on the surface of the short strain mold 140 is performed.

The thermal spraying step (S13) is masked with a high-temperature glass fiber to the portion (side) where the alloy layer 144 is not formed, and the nickel (Ni) -chromium (Cr) alloy powder high-speed flame spraying method (HVOF; High Velocity Oxygen Fuel Spraying) is performed in the order of forming the alloy layer 144 of 1 to 3 mm.

The high speed flame spraying method (HVOF) is a method of generating a high-speed jet by burning a fuel gas (propane, methylacetylene, heptane, hydrogen, etc.) at high pressure with oxygen, in the present invention, the flame by the high speed flame spraying method (HVOF) Hydrogen is used as a fuel to obtain.

The fuel gas composition of the high-speed flame spraying method (HVOF) is not particularly limited, but in the present invention, the volume ratio of hydrogen: oxygen is 1: 2 to 2.5, and the nickel (Ni) -chromium (Cr) alloy powder is By weight, it contains chromium (Cr) 7.5 to 17, boron (B) 1.6 to 4.2, silicon (Si) 3.5 to 4.5, carbon (C) 0.25 to 0.9, iron (Fe) 0.25 to 4.2%, and the balance Is composed of nickel (Ni) and other unavoidable impurities.

In this case, the particle size of the nickel (Ni) -chromium (Cr) alloy powder may be sufficiently melted in a range of 15 to 50 μm to be suitable for the high speed flame spraying method (HVOF).

Therefore, although hydrogen and oxygen, fuel gases, are not shown in a mixture, they are combusted in a combustion chamber inside a thermal spray gun, and the flames (jets) thus burned form a flame at a high temperature and high speed through a narrow and long barrel. The temperature of is 3170 ~ 3440K and the speed of the flame is sprayed Mach 3 ~ 7 and the nickel (Ni)-chromium (Cr) alloy powder is supplied to the center of the barrel is heated inside the flame is the short deformation type 140 Is sprayed on the surface of the.

After the thermal spraying step S13 is performed, a heat treatment step S14 is performed to increase the density and hardness of the alloy layer 144 formed on the right surface of the short strain mold 140.

The heat treatment step (S14) is carried out in a vacuum furnace (not shown) having a vacuum degree of less than 1 × 10 ^-3 Torr, the temperature is 1065 ℃, the alloy layer in the vacuum furnace for about 20 minutes Maintaining the short side mold 140, the 144 is formed and then rapid cooling.

In this rapid cooling, the argon (Ar) gas of 0.9 atm lower than 1 atm is injected into the vacuum furnace to maintain the vacuum degree of the vacuum furnace, and the argon (Ar) gas is circulated using a fan (not shown). The short side mold 140 is cooled, and argon (Ar) gas heated in the vacuum furnace is continuously cooled by passing through a heat exchanger (not shown) on one side of the vacuum furnace while being circulated by the fan.

Then, the vacuum pump (not shown) of the vacuum furnace was operated again to bring the vacuum degree of the vacuum furnace to 1 × 10 ^-3 Torr or lower and to rise to a temperature of 450 to 500 ° C., followed by precipitation hardening for 4 hours. By heat treatment, the density and hardness of the alloy layer 144 are strengthened, and the strength of the short strain mold 140 softened at the heat treatment temperature of the alloy layer 144 is restored.

Therefore, the alloy layer 144 to improve the wear resistance is formed on the right outer surface of the short side strain 140 by the above method.

After the alloy layer 144 is formed, a post-processing step (S15) is performed to polish to match the desired thickness and plan view of the alloy layer 144. The post-processing step (S15) is to polish the alloy layer 144 using a planar grinding machine (not shown).

In addition, the meniscus portions 122 and 142 in contact with the molten steel of the upper half of the inner surface of the continuous casting mold 100, more specifically, the right side and the long side mold 120 of the short side strainer 140 as shown in FIG. 5. The coating layer 146 is formed on the front surface to prevent the occurrence of heat cracks.

The coating layer 146 is a ceramic coating layer, magnesia (MgO), zirconia (ZrO ₂ ), yttria (Y ₂ O ₃ ), chromia (Cr ₂ O ₃ ), alumina (Al ₂ O ₃ ), titania (TiO) _It is formed by a plasma spray method using at least one of ₂ ).

Here, the plasma spraying method converts gases such as argon (Ar), helium (He), and nitrogen (N ₂ ) into an arc, and discharges them from the nozzle to discharge the ultra-high-temperature, high-speed plasma jet as a heat source. As a technique for forming a film, the plasma generator comprises a circular anode made of copper (Cu) and a cathode made of tungsten (W), in which the electric arc discharge plasmates the working gas to form a jet. .

In the present invention, a small amount of hydrogen (H ₂ ) which improves argon (Ar) and enthalpy is used as the plasma gas, and the flow rate ratio of the gas is argon (Ar): hydrogen (H ₂ ) = 85: A ceramic powder of 8% yttria (Y ₂ O ₃ ) -82% zirconia (ZrO ₂ ) is used as the ratio of 15.

Therefore, while the ceramic powder is dissolved in a plasma flame at a temperature of 4,000 to 10,000 ° C., the ceramic powder is scattered at a speed of 150 to 300 m / s and coated on the alloy layer 144 to form a coating layer 146.

In addition, the coating layer 146 is formed on the right side of the coating layer 146 in order to further form a coating layer 148 to further apply boron nitride (BN) to improve the wear resistance and heat resistance of the coating layer 146. Boron nitride (BN) of the coating layer 148 is applied to the coating layer 146 to a thickness of 20 to 25㎛ using a brush as a molten release agent used as a coating agent (塗布 劑).

Accordingly, an alloy layer 144 is formed on the surface of the short side strain 140, a coating layer 146 is formed on the upper half of the alloy layer 144, and an application layer 148 is formed on the coating layer 146. The continuous casting mold 100 is improved to wear resistance.

8 shows a process flow diagram showing a process of forming an alloy layer and a plating layer in the continuous casting mold of the present invention, Figure 9 shows a state in which the alloy layer and the plating layer and the coating layer is formed in the continuous casting mold of the present invention. A cross section is shown.

As shown in these figures, the continuous casting mold 100 is divided into the upper and lower parts of the right side of the continuous casting mold 100 by using the high speed flame spraying method (HVOF) and the electroplating method, respectively, into different components. It may be formed of an alloy layer 144 and a plating layer 144 '.

That is, as shown in FIG. 8, the nickel (Ni) -chromium (Cr) alloy is fastened by the high-speed flame spraying method (HVOF), as shown in FIG. 6, below the right side of the short side mold 140 of the continuous casting mold 100. The alloy layer 144 to be sprayed is formed, and the plating layer 144 ′ is plated by electroplating using any one of chromium (Cr), nickel (Ni), and nickel alloy on the alloy layer 144. It can be configured to form.

The process of forming the alloy layer 144 in the lower half of the short side strain 140 is performed in the washing step (S21), pretreatment step (S22), spraying step (S23), heat treatment step (S24) as in FIG. .
Here, the masking in the pretreatment process (S22) is performed on the upper right side and the front / rear upper part of the short side strainer 140 as shown in FIG. 9 to areas where the flame spraying by the HVOF is unnecessary. Do not over spray.

After the heat treatment step S24 is performed, a plating step S25 is performed to form the plating layer 144 ′ on the upper half of the short side strain 140, that is, on the upper side of the alloy layer 144. The plating process (S25) is carried out using any one of chromium (Cr), nickel (Ni), nickel alloy, in the present invention is plated by using nickel (Ni) as an embodiment.

The plating process (S25) masks the unplated portion (the lower half of the alloy layer and the side portion) except for the upper right side of the short side die 140 with a masking tape, etc. Plating is performed.

The washing is performed by using a conventional cleaning agent to remove the foreign substances present on the upper right side of the short side mold 140, after washing with water using a sodium hydroxide (NaOH) 80 ~ 150g / ℓ of electrolytic polishing agent 5 Electrolytic polishing is performed under the condition of ~ 10 A / dm 2, followed by washing with ion-exchanged water until the pH is neutral.

After this process is plated on the upper half of the short side strain 140, the composition of the plating solution required is nickel metal (Ni) 40 ~ 80g / L, nickel chloride (NiCl ₂ ) 25 ~ 30g / L, It is composed of boric acid 25 ~ 40g / ℓ, the electroplating is performed on the upper half of the short-strained 140 at the temperature of 45 ~ 55 ℃, pH of 3.5 ~ 4.0, and current density of 1 ~ 10A / ㎡ .

After the electroplating proceeds as described above, a post-processing step (S26) of polishing the plating layer 144 'and the alloy layer 144 formed on the upper and lower right sides of the short side deformation die 140 to match the desired thickness and plan view is performed. do. In the post-processing step S26, the alloy layer 144 and the plating layer 144 'are polished using a planar grinding machine (not shown) as in FIG.

In addition, a heat crack is prevented from occurring in the meniscus portion 142 of the plating layer 144 'among the plating layers 144' and the alloy layer 144 formed on the upper and lower sides of the short side strain 140. In order to form a coating layer 146 ′.

The coating layer 146 ′ is a ceramic coating layer as described above, magnesia (MgO), zirconia (ZrO ₂ ), yttria (Y ₂ O ₃ ), chromia (Cr ₂ O ₃ ), alumina (Al ₂ O ₃₎ ) And at least one of titania (TiO ₂ ) to form the above-mentioned plasma spray method.

In addition, the coating layer 148 ′ is formed on the right side of the coating layer 146 ′ to further apply boron nitride (BN) to improve wear resistance and heat resistance of the coating layer 146 ′. Boron nitride (BN) of the coating layer 148 ′ is applied to the coating layer 146 ′ with a thickness of 20 to 25 μm using a brush as described above.

Therefore, an alloy layer 144 is formed below the right side of the short side strain 140, a plating layer 144 'is formed on the upper side of the right side of the short side strain 140, and the center of the right side of the plated layer 144' The coating layer 146 ′ and the coating layer 148 ′ are further formed to complete the continuous casting mold 100 having improved wear resistance.

FIG. 10 shows a structure photograph of an alloy layer formed by HVOF using a nickel (Ni) -chromium (Cr) alloy, and FIG. 11 shows a high speed flame using a nickel (Ni) -chromium (Cr) alloy. The structure photograph after heat-treating the alloy layer formed by the thermal spraying method (HVOF) in an atmosphere furnace is shown. In FIG. 12, the alloy layer formed by the high-temperature flame spraying method (HVOF) by nickel (Ni) -chromium (Cr) alloy is vacuum furnace. A tissue photograph after heat treatment at is shown.

As shown in these tissue photographs, when using the high-speed flame spraying method (HVOF) as shown in Figure 10 due to the high flame speed of Mach 3-7, the pores of the alloy layer 144 is significantly reduced, the subsequent atmosphere The heat treatment in the furnace still shows some coarse pores as shown in FIG. 11, but in the vacuum furnace, as shown in FIG. 12, the pores are removed by the vacuum atmosphere. Since the structure of the alloy layer 144 having excellent hardness can be obtained, the continuous casting mold 100 having improved wear resistance made of the alloy layer 144 is completed.

The scope of the present invention is not limited to the above-exemplified embodiments, and many other modifications based on the present invention may be made by those skilled in the art within the above technical scope.

As described in detail above, in the continuous casting mold according to the present invention, the inner surface of the injection hollow portion of the continuous casting mold is plated by a high-temperature flame spraying method (HOVF) using a nickel (Ni) -chromium (Cr) alloy to obtain a vacuum heat treatment furnace. The alloy layer formed by finishing is formed or the lower half of the inner surface of the injection hollow part of the continuous casting mold is plated by using a nickel (Ni) -chromium (Cr) alloy by high speed flame spraying (HOVF) to form an alloy layer. The upper half is configured to form a plating layer formed by plating by electroplating using any one of chromium (Cr), nickel (Ni), and nickel alloy.

The coating layer is formed by applying ceramic coating to the alloy layer and the plating layer, and a molten release agent such as boron nitride (BN) is further applied to the coating layer.

Therefore, it is possible to prevent the occurrence of heat cracks formed on the surface of the continuous casting mold (meniscus portion), and the continuous casting mold due to the advantage that the wear resistance of the continuous casting mold is significantly improved. The effect of extending the life of the quiet mold is expected to be much longer.

Claims (6)

In the continuous casting mold provided with a coolant jacket and made of copper (Cu) or copper alloy, On the inner surface of the injection hollow portion of the continuous casting mold, An alloy layer is formed by spraying a nickel (Cr) -chromium (Cr) alloy with a high-speed flame spraying method (HVOF) and finishing with vacuum heat treatment. The alloy layer of the nickel (Ni) -chromium (Cr) alloy, By weight, it contains 7.5 to 17% of chromium (Cr), 1.6 to 4.2% of boron (B), 3.5 to 4.5% of silicon (Si), 0.25 to 0.9% of carbon (C), and 0.25 to 4.2% of iron (Fe). Mold for continuous casting, characterized in that the balance is composed of nickel (Ni) and other unavoidable impurities. According to claim 1, wherein the upper outer surface of the alloy layer, Plasma using at least one of magnesia (MgO), zirconia (ZrO ₂ ), yttria (Y ₂ O ₃ ), chromia (Cr ₂ O ₃ ), alumina (Al ₂ O ₃ ), titania (TiO ₂ ) (Plasma) Mold for continuous casting, characterized in that the coating layer is formed by the thermal spraying method. In the continuous casting mold provided with a coolant jacket and made of copper (Cu) or copper alloy, On the inner surface of the injection hollow portion of the continuous casting mold, By weight, it contains 7.5 to 17% of chromium (Cr), 1.6 to 4.2% of boron (B), 3.5 to 4.5% of silicon (Si), 0.25 to 0.9% of carbon (C), and 0.25 to 4.2% of iron (Fe). An alloy layer in which a nickel (Ni) -chromium (Cr) alloy whose balance is composed of nickel (Ni) and other unavoidable impurities is sprayed by a high-speed flame spraying method (HVOF), Continuous casting mold, characterized in that the plating layer is plated by electroplating using any one of chromium (Cr), nickel (Ni), nickel alloy on the upper side of the alloy layer. According to claim 3, At one side of the outer surface of the plating layer, Plasma using at least one of magnesia (MgO), zirconia (ZrO ₂ ), yttria (Y ₂ O ₃ ), chromia (Cr ₂ O ₃ ), alumina (Al ₂ O ₃ ), titania (TiO ₂ ) (Plasma) Mold for continuous casting, characterized in that the coating layer is formed by the thermal spraying method. The mold for continuous casting according to claim 2 or 4, wherein boron nitride (BN) is further applied to the coating layer. delete

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