Method for improving smoothness of inner wall of ingot mold

Abstract

The invention relates to a method for improving the smoothness of the inner wall of an ingot mold, which comprises the following steps of: after a steel ingot is demolded, increasing the temperature of the inner wall of the ingot mold to 280-330 DEG C, uniformly blowing an argon-iron powder mixture to the inner wall of the ingot mold by using a blowing system, reducing the temperature of the inner wall of the ingot mold to 200-250 DEG C after blowing, keeping the temperature for more than 5 minutes, and then reducing the temperature to the temperature of a column mold. By blowing the argon and iron powder mixture, on one hand, the effect of cleaning slag spots and residual steel is achieved, on the other hand, pits in the inner wall of the steel ingot mold can be repaired, the smoothness and cleanliness of the inner wall of the steel ingot mold are effectively improved, and the device is suitable for steel ingot molds with inner cavities in different shapes.

Description

Technical Field

[0001] The invention relates to the technical field of casting, and in particular to a method for improving the smoothness of the inner wall of a steel ingot mould. Background Art

[0002] After the steel ingot is cast and taken out of the mold, the inner wall of the steel ingot mold needs to be cleaned in time. On the one hand, it is to avoid surface quality problems such as pits, slag inclusions, and pores in the subsequent steel ingots due to slag spots, residual steel, pits, and protrusions on the inner wall. On the other hand, it is beneficial to reduce the labor intensity of workers in the subsequent steel ingot grinding process and improve the steel ingot recovery rate.

[0003] At present, most steel ingot molds are cleaned by using a shovel to clean the slag spots. This cleaning method has the following problems: (1) The cleaning operation consumes manpower and material resources and is labor-intensive; (2) The shovel can only clean the obvious foreign matter adhering to the inner wall of the steel ingot mold, but cannot clean the residual cold slag, and it is even more difficult to clean the pits, protrusions and dead corners of the inner wall. The cleaning efficiency is low and the cleaning effect is poor; if the foreign matter on the inner wall of the steel ingot mold accumulates for a long time, it will cause the steel ingot defects to exceed the standard or even reach the scrap standard, resulting in increased production costs. (3) The inner cavity of the steel ingot mold has different shapes. Using a shovel of the same specification to clean the inner wall of the steel ingot mold is not universal and the treatment effect is unsatisfactory.

[0004] A Chinese patent application with application publication number CN 117548386A discloses "a device for cleaning the inner wall of a steel ingot mold", which uses a rotating column to drive a flexible steel wire brush to remove slag and impurities from the inner wall and bottom wall of the steel ingot mold. After a counterweight ring is added to the bottom steel wire, the cleaning effect is effectively improved.

[0005] The Chinese utility model patent with authorization announcement number CN 218697327U discloses "a device for cleaning the inner wall of a steel ingot mold", which uses friction of a grinding plate driven by a vibration motor to eliminate steel slag or impurities on the inner wall of the steel ingot mold, and can clean the inner walls of both sides of the steel ingot mold at the same time.

[0006] The Chinese utility model patent with authorization announcement number CN 204504213U discloses "a device for cleaning the inner wall of a square steel ingot mold", which uses a height-adjustable grinding wheel and a mobile trolley to clean the inner wall of a steel ingot. It is suitable for square steel ingot molds of different sizes, reducing costs.

[0007] The above-mentioned cleaning device has poor adaptability to ingot molds with inner cavities of different shapes, and its main purpose is to clean slag spots, residual steel and other impurities remaining on the inner wall of the ingot mold. It cannot repair the pits on the inner wall of the ingot mold. After cleaning, the smoothness and cleanliness of the inner wall of the ingot mold is still not enough. Summary of the invention

[0008] The present invention provides a method for improving the smoothness of the inner wall of a steel ingot mold. After the steel ingot is demolded, the temperature of the inner wall of the steel ingot mold is controlled, and an argon gas and iron powder mixture is sprayed toward the inner wall of the steel ingot mold. On the one hand, slag spots and residual steel can be cleaned, and on the other hand, pits on the inner wall of the steel ingot mold can be repaired, thereby effectively improving the smoothness and cleanliness of the inner wall of the steel ingot mold, and the method is suitable for use with steel ingot molds with inner cavities of different shapes.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A method for improving the smoothness of the inner wall of a steel ingot mold. After the steel ingot is demolded, the temperature of the inner wall of the steel ingot mold is increased to 280-330°C, and then an argon gas iron powder mixture is evenly sprayed onto the inner wall of the steel ingot mold by a spraying system. After the spraying is completed, the temperature of the inner wall of the steel ingot mold is reduced to 200-250°C and kept warm for more than 5 minutes, and then cooled to the column mold temperature.

[0011] A method for improving the smoothness of the inner wall of a steel ingot mold comprises the following steps:

[0012] 1) After the molten steel is poured, the ingot is demoulded when the temperature of the ingot mold drops to 50-90°C;

[0013] 2) After demoulding, the inner wall temperature of the ingot mold is raised to 280-330°C;

[0014] 3) Adjust the pressure of the powder spraying system to 1.5-2.0 MPa;

[0015] 4) Using a powder spraying system to spray an argon-iron powder mixture from top to bottom on the inner wall of the steel ingot mold, the spraying direction is at an angle of 45° to 60° to the axial direction of the steel ingot mold, and the spraying range covers the entire surface of the inner wall of the steel ingot mold;

[0016] 5) Using a powder spraying system to spray argon iron powder mixture 2 on the inner wall of the steel ingot mold from bottom to top, the spraying direction is at an angle of 45° to 60° to the axial direction of the steel ingot mold, and the spraying range covers the entire surface of the inner wall of the steel ingot mold;

[0017] 6) After the spraying is completed, the temperature of the inner wall of the ingot mold drops to 200-250℃ and is kept warm for more than 5 minutes;

[0018] 7) After the insulation is completed, the ingot mold is cooled to the column mold temperature, which is 90-110°C.

[0019] In the step 4), the moving speed of the powder spraying system when spraying from top to bottom is 1.5-2.0 m / min.

[0020] The ratio of the argon-iron powder mixture is 1-3 kg of iron powder per cubic meter of argon.

[0021] In the argon-iron powder mixture, the particle size of the iron powder is in the range of 200 to 400 μm.

[0022] In the step 5), the moving speed of the powder spraying system when spraying from bottom to top is 1.0-1.4 m / min.

[0023] The proportion of the argon-iron powder mixture 2 is 6-10 kg of iron powder per cubic meter of argon.

[0024] In the second argon-iron powder mixture, the particle size of the iron powder is in the range of 0.5 to 10 μm.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1) By controlling the temperature of the inner wall of the ingot mold and the technical parameters when spraying the argon iron powder mixture in the ingot mold (including the moving speed during spraying, the iron powder content in the mixture, the iron powder particle size, the spraying angle, etc.), the residue on the inner wall of the ingot mold can be effectively cleaned, and the pits on the inner wall can be repaired, thereby improving the smoothness of the inner wall of the ingot mold.

[0027] 2) By controlling the temperature of the inner wall of the ingot mold and spraying argon iron powder mixture 1 from top to bottom along the angle of 45 to 60° with the axial direction of the ingot mold (compared with argon iron powder mixture 2, the iron powder content in the argon is relatively small and the iron powder particle size is relatively large), the temperature, spraying angle and the impact force of the argon entrained with a small amount of large-particle iron powder are synergistically exerted during the spraying process. On the one hand, the inner wall of the ingot mold can be finely cleaned, and on the other hand, an extremely thin iron powder spray layer can be formed on the inner wall of the ingot mold, thereby improving the smoothness of the inner wall of the ingot mold.

[0028] 3) In the process of spraying the argon-iron powder mixture from bottom to top, by adjusting the spraying direction of the argon-iron powder mixture, selecting iron powder of appropriate particle size and controlling the iron powder content in the argon, and cooling and solidifying the iron powder after the spraying, the pits on the inner wall of the ingot mold can be repaired and the smoothness of the inner wall of the ingot mold can be improved.

[0029] 4) The method of the present invention can be used to clean the inner wall of a steel ingot mold with an inner cavity of different shapes, which is beneficial to improving the surface quality of the steel ingot, reducing the frequency of steel ingot grinding, improving the steel ingot recovery rate, and reducing the labor intensity of workers. DETAILED DESCRIPTION

[0030] The present invention discloses a method for improving the smoothness of the inner wall of a steel ingot mold. After the steel ingot is demolded, the temperature of the inner wall of the steel ingot mold is increased to 280-330°C, and then an argon gas iron powder mixture is evenly sprayed onto the inner wall of the steel ingot mold by a spraying system. After the spraying is completed, the temperature of the inner wall of the steel ingot mold is reduced to 200-250°C and kept warm for more than 5 minutes, and then cooled to the mold temperature.

[0031] The method for improving the smoothness of the inner wall of a steel ingot mold described in the present invention specifically comprises the following steps:

[0032] 1) After the molten steel is poured, the ingot is demoulded when the temperature of the ingot mold drops to 50-90°C;

[0033] 2) After demoulding, the inner wall temperature of the ingot mold is raised to 280-330°C;

[0034] 3) Adjust the pressure of the powder spraying system to 1.5-2.0 MPa;

[0035] 4) Using a powder spraying system to spray an argon-iron powder mixture from top to bottom on the inner wall of the steel ingot mold, the spraying direction is at an angle of 45° to 60° to the axial direction of the steel ingot mold, and the spraying range covers the entire surface of the inner wall of the steel ingot mold;

[0036] 5) Using a powder spraying system to spray argon iron powder mixture 2 on the inner wall of the steel ingot mold from bottom to top, the spraying direction is at an angle of 45° to 60° to the axial direction of the steel ingot mold, and the spraying range covers the entire surface of the inner wall of the steel ingot mold;

[0037] 6) After the spraying is completed, the temperature of the inner wall of the ingot mold drops to 200-250℃ and is kept warm for more than 5 minutes;

[0038] 7) After the insulation is completed, the ingot mold is cooled to the column mold temperature, which is 90-110°C.

[0039] In the step 4), the moving speed of the powder spraying system when spraying from top to bottom is 1.5-2.0 m / min.

[0040] The ratio of the argon-iron powder mixture is 1-3 kg of iron powder per cubic meter of argon.

[0041] In the argon-iron powder mixture, the particle size of the iron powder is in the range of 200 to 400 μm.

[0042] In the step 5), the moving speed of the powder spraying system when spraying from bottom to top is 1.0-1.4 m / min.

[0043] The proportion of the argon-iron powder mixture 2 is 6-10 kg of iron powder per cubic meter of argon.

[0044] In the second argon-iron powder mixture, the particle size of the iron powder is in the range of 0.5 to 10 μm.

[0045] In order to more intuitively embody the present invention, the embodiments of the present invention are further described in conjunction with the examples. The following examples are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any technical solution that can be obviously obtained by a person skilled in the art within the technical scope disclosed in the present invention, including simple changes or equivalent replacements, is within the protection scope of the present invention.

[0046] [Example 1]

[0047] In this embodiment, the cast steel ingot is D406C steel, and the steel ingot mold used is a 23t flat ingot mold. In order to improve the smoothness of the inner wall of the steel ingot mold, the following measures are taken:

[0048] 1) After the molten steel is poured, the ingot is demoulded when the temperature of the ingot mold drops to 90°C.

[0049] 2) After demoulding, the inner wall temperature of the ingot mold is raised to 330°C.

[0050] 3) Adjust the pressure of the powder spraying system to 1.5MPa.

[0051] 4) Using a powder spraying system, spray an argon-iron powder mixture 1 on the inner wall of the ingot mold from top to bottom, the spraying direction is at an angle of 45° to the axial direction of the ingot mold, and the spraying range covers the entire surface of the inner wall of the ingot mold; the moving speed of the powder spraying system is 1.5 m / min, the ratio of the argon-iron powder mixture 1 is 1 kg of iron powder per cubic meter of argon, and the particle size range of the iron powder is 200-300 μm.

[0052] 5) Using a powder spraying system, spray argon-iron powder mixture 2 from bottom to top on the inner wall of the steel ingot mold, the spraying direction is at an angle of 45° to the axial direction of the steel ingot mold, and the spraying range covers the entire surface of the inner wall of the steel ingot mold; the moving speed of the powder spraying system is 1.4 m / min, the ratio of argon-iron powder mixture 2 is 10 kg of iron powder per cubic meter of argon, and the particle size range of the iron powder is 5 to 10 μm.

[0053] 6) After the spraying is completed, the inner wall temperature of the ingot mold drops to 220℃ and is kept warm for 5.5 minutes.

[0054] 7) After the insulation is completed, the ingot mold is cooled to the column mold temperature, which is 110°C.

[0055] Implementation effect: Compared with the method of using a shovel to clean the inner wall of the ingot mold, the implementation improves the smoothness and neatness of the inner wall of the ingot mold. After blast cleaning, there is no slag spot or residual steel on the inner wall of the ingot mold, and the pits on the inner wall are repaired. The defect rate of surface slag or pits in the subsequently produced ingots is reduced by 12.6%.

[0056] [Example 2]

[0057] In this embodiment, the cast steel ingot is 35CrMo steel, and the steel ingot mold used is a 100t octagonal ingot mold. In order to improve the smoothness of the inner wall of the steel ingot mold, the following measures are taken:

[0058] 1) After the molten steel is poured, the ingot is demoulded when the temperature of the ingot mold drops to 50°C.

[0059] 2) After demoulding, the inner wall temperature of the ingot mold is raised to 280°C.

[0060] 3) Adjust the pressure of the powder spraying system to 2.0 MPa.

[0061] 4) Using a powder spraying system, spray an argon-iron powder mixture 1 on the inner wall of the ingot mold from top to bottom, the spraying direction is at an angle of 60° to the axial direction of the ingot mold, and the spraying range covers the entire surface of the inner wall of the ingot mold; the moving speed of the powder spraying system is 2.0 m / min, the ratio of the argon-iron powder mixture 1 is 3 kg of iron powder per cubic meter of argon, and the particle size range of the iron powder is 300-400 μm.

[0062] 5) The powder spraying system is used to spray argon-iron powder mixture 2 on the inner wall of the ingot mold from bottom to top, the spraying direction is at an angle of 60° to the axial direction of the ingot mold, and the spraying range covers the entire surface of the inner wall of the ingot mold; the moving speed of the powder spraying system is 1.0 m / min, the ratio of argon-iron powder mixture 2 is 6 kg of iron powder per cubic meter of argon, and the particle size range of the iron powder is 0.5 to 5 μm.

[0063] 6) After the spraying is completed, the inner wall temperature of the ingot mold drops to 250℃ and is kept warm for 7 minutes.

[0064] 7) After the insulation is completed, the ingot mold is cooled to the column mold temperature, which is 90°C.

[0065] Implementation effect: Compared with the method of using a shovel to clean the inner wall of the steel ingot mold, the implementation improves the smoothness and neatness of the inner wall of the steel ingot mold. After blast cleaning, there is no slag spot or residual steel on the inner wall of the steel ingot mold, and the pits on the inner wall are repaired. The defect rate of surface slag or pits in the subsequently produced steel ingots is reduced by 13.5%.

[0066] [Example 3]

[0067] In this embodiment, the cast steel ingot is J80 steel, and the steel ingot mold used is a 13.5t flat ingot mold. In order to improve the smoothness of the inner wall of the steel ingot mold, the following measures are taken:

[0068] 1) After the molten steel is poured, the ingot is demoulded when the temperature of the ingot mold drops to 70°C.

[0069] 2) After demoulding, the inner wall temperature of the ingot mold is raised to 300°C.

[0070] 3) Adjust the pressure of the powder spraying system to 1.7MPa.

[0071] 4) Using a powder spraying system, an argon-iron powder mixture is sprayed on the inner wall of the ingot mold from top to bottom. The spraying direction is at an angle of 50° to the axial direction of the ingot mold, and the spraying range covers the entire surface of the inner wall of the ingot mold. The moving speed of the powder spraying system is 1.7 m / min, and the ratio of the argon-iron powder mixture is 2 kg of iron powder per cubic meter of argon, and the particle size range of the iron powder is 250-350 μm.

[0072] 5) The powder spraying system is used to spray argon-iron powder mixture 2 on the inner wall of the ingot mold from bottom to top, the spraying direction is at an angle of 50° to the axial direction of the ingot mold, and the spraying range covers the entire surface of the inner wall of the ingot mold; the moving speed of the powder spraying system is 1.2 m / min, the ratio of argon-iron powder mixture 2 is 8 kg of iron powder per cubic meter of argon, and the particle size range of the iron powder is 3 to 6 μm.

[0073] 6) After the spraying is completed, keep the inner wall temperature of the ingot mold to 240℃ for 10 minutes.

[0074] 7) After the insulation is completed, the ingot mold is cooled to the mold temperature, which is 100°C.

[0075] Implementation effect: Compared with the method of using a shovel to clean the inner wall of the ingot mold, the implementation improves the smoothness and neatness of the inner wall of the ingot mold. After blast cleaning, there is no slag spot or residual steel on the inner wall of the ingot mold, and the pits on the inner wall are repaired. The defect rate of surface slag or pits in the subsequently produced ingots is reduced by 15.7%.

[0076] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for improving the smoothness of the inner wall of an ingot mold, characterized in that: After the ingot is demolded, the temperature of the inner wall of the ingot mold is increased to 280-330°C, and then the argon iron powder mixture is evenly sprayed onto the inner wall of the ingot mold using the blowing system. After the blowing is completed, the temperature of the inner wall of the ingot mold drops to 200-250°C and is kept warm for more than 5 minutes, and then cooled to the column mold temperature.

2. A method for improving the smoothness of the inner wall of a steel ingot mold according to claim 1, characterized in that: The specific steps include: 1) After the molten steel is poured, the ingot is demoulded when the temperature of the ingot mold drops to 50-90°C; 2) After demoulding, the inner wall temperature of the ingot mold is raised to 280-330°C; 3) Adjust the pressure of the powder spraying system to 1.5-2.0 MPa; 4) Using a powder spraying system to spray an argon iron powder mixture from top to bottom on the inner wall of the steel ingot mold, the spraying direction is at an angle of 45° to 60° to the axial direction of the steel ingot mold, and the spraying range covers the entire surface of the inner wall of the steel ingot mold; 5) Using a powder spraying system to spray argon iron powder mixture 2 on the inner wall of the steel ingot mold from bottom to top, the spraying direction is at an angle of 45° to 60° to the axial direction of the steel ingot mold, and the spraying range covers the entire surface of the inner wall of the steel ingot mold; 6) After the spraying is completed, the temperature of the inner wall of the ingot mold drops to 200-250°C and is kept warm for more than 5 minutes; 7) After the insulation is completed, the ingot mold is cooled to the column mold temperature, which is 90-110°C.

3. A method for improving the smoothness of the inner wall of a steel ingot mold according to claim 1, characterized in that: In the step 4), the moving speed of the powder spraying system when spraying from top to bottom is 1.5-2.0 m / min.

4. A method for improving the smoothness of the inner wall of a steel ingot mold according to claim 1, characterized in that: The ratio of the argon-iron powder mixture is 1-3 kg of iron powder per cubic meter of argon.

5. A method for improving the smoothness of the inner wall of a steel ingot mold according to claim 1, characterized in that: In the argon-iron powder mixture, the particle size of the iron powder is in the range of 200 to 400 μm.

6. A method for improving the smoothness of the inner wall of a steel ingot mold according to claim 1, characterized in that: In the step 5), the moving speed of the powder spraying system when spraying from bottom to top is 1.0-1.4 m / min.

7. A method for improving the smoothness of the inner wall of a steel ingot mold according to claim 1, characterized in that: The proportion of the argon-iron powder mixture 2 is 6-10 kg of iron powder per cubic meter of argon.

8. A method for improving the smoothness of the inner wall of a steel ingot mold according to claim 1, characterized in that: In the second argon-iron powder mixture, the particle size of the iron powder is in the range of 0.5 to 10 μm.