Inner conical argon protection ring and preparation method thereof

Abstract

The present invention relates to an inner conical argon protection ring and a preparation method thereof, belonging to the technical field of the smelting industry, and solving the problem that the existing argon protection ring has poor air isolation effect and poor effect in controlling molten steel suction during steel ingot casting. An inner conical argon protection ring comprises an inner sleeve, an outer sleeve and a main pipe sequentially arranged from the inside to the outside; the main pipe is a hollow annular pipe, which is connected to the outer sleeve through an air inlet pipe; the inner sleeve is a conical hollow sleeve, which is connected to the outer sleeve through an air outlet hole opened on the conical surface; the inner sleeve and the top end of the outer sleeve are connected through a cover plate, and the bottom end of the inner sleeve is connected to the inner wall side of the outer sleeve through a middle plate, and the outer wall of the inner sleeve, the inner wall of the outer sleeve, the lower end face of the cover plate and the upper end face of the middle plate together form an air chamber. The argon protection ring of the present invention improves the effect of controlling molten steel suction.

Description

Technical Field

[0001] The invention relates to the technical field of smelting industry, in particular to an inner conical argon protection ring and a preparation method thereof. Background Art

[0002] Ingot pouring is a crucial step in the die casting process, as it can easily lead to secondary oxidation and gas absorption in the molten steel. Common ingot pouring techniques include vacuum top pouring and atmospheric bottom pouring. Currently, vacuum top pouring ingots can produce up to 715 tons. Factors limiting the production capacity of atmospheric bottom pouring ingots include the erosion resistance of the casting system's refractory materials and the control of gas content in atmospheric bottom pouring ingots.

[0003] With the improvement of vacuum system capabilities in the steel refining process, hydrogen content can be controlled below 1 ppm during the refining stage, which has created an opportunity for large-scale production of atmospherically cast steel ingots. Atmosphericly cast steel ingot casting technology offers significant advantages in inclusion removal, primarily because the molten steel flows from the bottom to the top of the ingot during pouring, which facilitates the floating of inclusions in the molten steel. At the same time, atmospherically cast steel ingots can lower pouring temperatures and reduce the consumption of refractory materials and metallurgical auxiliary tools.

[0004] Preventing molten steel from aspirating during atmospheric casting is crucial for controlling the gas content in the ingot. The key to preventing aspirated steel lies in the argon shielding in the ladle's inlet area. However, existing cylindrical argon shielding rings struggle to create a positive pressure environment in the inlet area, resulting in poor air-isolating protection and limited control of molten steel aspiration. Therefore, improvements to existing argon shielding equipment are urgently needed to enhance their air-isolating effectiveness. Summary of the Invention

[0005] In view of the above analysis, an embodiment of the present invention aims to provide an inner conical argon protection ring and a preparation method thereof, so as to solve the problem that the existing argon protection equipment has poor air isolation effect and poor control effect on molten steel intake during the atmospheric pouring steel ingot casting process.

[0006] In one aspect, the present invention provides an inner conical argon protection ring, which comprises an inner sleeve, an outer sleeve and a main pipe sequentially arranged from the inside to the outside;

[0007] The main pipe is a hollow annular pipe and is connected to the outer sleeve through the air inlet pipe;

[0008] The inner sleeve is a conical hollow sleeve, which is connected to the outer sleeve through the air outlet hole opened on the conical surface;

[0009] The top ends of the inner sleeve and the outer sleeve are connected through a cover plate, the bottom end of the inner sleeve is connected to the inner wall side of the outer sleeve through a middle plate, and the outer wall of the inner sleeve, the inner wall of the outer sleeve, the lower end face of the cover plate and the upper end face of the middle plate together form an air chamber.

[0010] Furthermore, the air outlet holes opened on the conical surface of the inner sleeve include upper air outlet holes and lower air outlet holes, and the upper air outlet holes and the lower air outlet holes have different opening directions.

[0011] Furthermore, the number of the upper layer air outlet holes and the lower layer air outlet holes is the same, both being N, and the value of N ranges from 4 to 16;

[0012] The upper air outlet holes and the lower air outlet holes are evenly distributed around the circumference of the inner sleeve.

[0013] Furthermore, the upper air outlet holes are 1 to 5 mm away from the top end surface of the inner sleeve, and the lower air outlet holes are 1 to 5 mm away from the bottom end surface of the inner sleeve.

[0014] Furthermore, the top surface of the inner sleeve is a horizontal plane, the upper air outlet hole maintains an angle α with the top surface of the inner sleeve, and the minimum value of α is min Satisfaction: sinα min =2×D 孔 / (D 上 -D 外 );

[0015] Wherein, α is the angle between the upper air outlet and the horizontal plane of the top surface of the inner sleeve, degrees;

[0016] D 孔 is the diameter of the vent hole, mm;

[0017] D 上 is the inner diameter of the upper opening of the inner sleeve, mm;

[0018] D 外 The outer diameter of the ladle nozzle refractory material, mm.

[0019] Furthermore, the bottom end surface of the inner sleeve is a horizontal plane, and the lower air outlet hole maintains an angle β with the horizontal plane of the bottom end surface of the inner sleeve, and the minimum value β of β min Satisfaction: sinβ min =2×D 孔 / (D 下 -D 砖 );

[0020] Wherein, β is the angle between the lower air outlet hole and the horizontal plane of the bottom end surface of the inner sleeve, degrees;

[0021] D 孔 is the diameter of the vent hole, mm;

[0022] D 下 is the inner diameter of the lower opening of the inner sleeve, mm;

[0023] D 砖 is the outer diameter of the basin brick inside the center injection pipe, mm.

[0024] Furthermore, the cover plate is an annular plate with a hole in the middle, and the outer diameter of the cover plate is equal to the outer diameter of the outer sleeve.

[0025] Furthermore, the height of the outer sleeve is 1.5 to 2.0 times the height of the inner sleeve.

[0026] Furthermore, when the steel ingot is cast using double-layer slide casting, the inner sleeve satisfies: 上 ≥D 外 and D 上 ≥L+D 水 / 2;

[0027] Among them, D 上 is the inner diameter of the upper opening of the inner sleeve, mm;

[0028] D 外 is the outer diameter of the ladle nozzle refractory, mm;

[0029] L is the sliding stroke of the nozzle when using double-layer slide casting, mm;

[0030] D 水 is the diameter of the ladle nozzle, mm;

[0031] When the steel ingot is cast using three-layer slide casting, the inner sleeve meets the following requirements: 下 >D 砖 ;

[0032] Among them, D 下 is the inner diameter of the lower opening of the inner sleeve, mm;

[0033] D 砖 is the outer diameter of the basin brick inside the center injection pipe, mm.

[0034] On the other hand, the present invention also provides a method for preparing an inner conical argon protection ring, which is used to prepare the inner conical argon protection ring according to any one of claims 1 to 9.

[0035] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0036] 1. Compared with the existing argon protection ring using a cylindrical inner sleeve, the present invention forms a certain positive pressure environment in the injection area through the design of an inner conical inner sleeve, solving the problems of poor air isolation effect and poor control of molten steel suction effect of existing argon protection equipment.

[0037] 2. The present invention ensures good argon protection effect and positive pressure environment of the gas chamber by evenly distributing gas outlet holes that meet angle requirements on the inner sleeve of the inner conical argon protection ring, while avoiding direct impact on the molten steel flow and improving the effect of controlling molten steel suction.

[0038] 3. The present invention staggers the inlet pipe and outlet holes of the inner conical argon protection ring to avoid the argon gas in the inlet pipe directly impacting the outlet holes, thereby causing the argon pressure of some outlet holes to be greater than that of other outlet holes, affecting the uniform distribution of the positive pressure environment in the air chamber; thus, the uniform distribution of the positive pressure environment in the air chamber is ensured, and the effect of controlling the air intake of molten steel is improved.

[0039] In the present invention, the above-mentioned technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of the present invention will be described in the following description, and some advantages will become apparent from the description or be learned through practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like parts throughout the drawings.

[0041] Figure 1 It is a cross-sectional schematic diagram of the inner conical argon protection ring structure of the present invention;

[0042] Figure 2 This is a cross-sectional view of the inner conical argon protection ring structure of the present invention taken along the AA direction;

[0043] Figure 3 for Figure 1 Schematic diagram of the structure of the inner conical argon protection ring when in use;

[0044] Figure 4 This is a schematic cross-sectional view of the existing cylindrical argon protection ring structure in Comparative Example 1 of the present invention.

[0045] Reference numerals:

[0046] 1-cover plate; 2-inner sleeve; 3-outer sleeve; 4-middle plate; 5-inlet pipe; 6-air chamber; 7-air outlet; 8-main pipe; 9-ladle water inlet; 10-ladle bottom; 11-asbestos board; 12-vent pipe; AA-cutting direction;

[0047] D 水 - diameter of the ladle nozzle; L - sliding stroke of the nozzle when using double-layer slide casting; D 外 -Outer diameter of ladle nozzle refractory material; D 砖 -Brick outer diameter; D中注管 -Outer diameter of the injection pipe;

[0048] H 外 -Outer sleeve height; H 内 -Inner sleeve height; D 上 -Inner diameter of the inner sleeve top; D 下 -Inner diameter of the lower end of the inner sleeve; D 孔 - Diameter of the air outlet; α - Angle maintained between the air outlet of the upper layer of the inner sleeve and the horizontal plane; β - Angle maintained between the air outlet of the lower layer of the inner sleeve and the horizontal plane. DETAILED DESCRIPTION

[0049] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, and are not used to limit the scope of the present invention.

[0050] The present invention provides an inner conical argon protection ring, comprising an inner sleeve, an outer sleeve and a main pipe which are sequentially sleeved from the inside to the outside;

[0051] The main pipe is a hollow annular pipe and is connected to the outer sleeve through the air inlet pipe;

[0052] The inner sleeve is a conical hollow sleeve, which is connected to the outer sleeve through the air outlet hole opened on the conical surface;

[0053] The top ends of the inner sleeve and the outer sleeve are connected through a cover plate, the bottom end of the inner sleeve is connected to the inner wall side of the outer sleeve through a middle plate, and the outer wall of the inner sleeve, the inner wall of the outer sleeve, the lower end face of the cover plate and the upper end face of the middle plate together form an air chamber.

[0054] Figure 1 It is a cross-sectional schematic diagram of the inner conical argon protection ring structure of the present invention; Figure 2 A cross-sectional view of the inner conical argon protection ring structure of the present invention taken along the AA direction.

[0055] A vent pipe is provided on the outside of the main pipe, which is connected to the main pipe by welding and is used to introduce argon gas.

[0056] The outer sleeve is a circular hollow sleeve, and the air inlet pipe is evenly distributed on its outside. The two ends of the air inlet pipe are connected to the outer sleeve and the main pipe respectively by welding.

[0057] Specifically, the inner diameter of the main pipe is consistent with the outer diameter of the ventilation pipe. To ensure the ventilation volume, the inner diameter of the main pipe is preferably 20-30 mm, and the wall thickness of the main pipe is 1-2 mm to ensure sufficient strength. Steel material is selected to ensure that it can be connected to the intake pipe by welding.

[0058] Specifically, the outer sleeve is rolled from steel plate. Its inner diameter is 10 to 25 mm larger than the outer diameter of the center injection tube; its wall thickness is 2 to 3 mm; and its height is 1.5 to 2.0 times the height of the inner sleeve. During use, the outer sleeve must be fitted onto the center injection tube. Therefore, a 10 to 25 mm margin is required relative to the outer diameter of the center injection tube to facilitate assembly. The outer sleeve wall thickness is 2 to 3 mm to ensure sufficient strength for reuse. The outer sleeve height is 1.5 to 2.0 times the height of the inner sleeve to ensure stability after fitting onto the center injection tube.

[0059] Specifically, the inner sleeve is rolled from a steel plate, and the height of the inner sleeve needs to take into account the gap between the bottom of the ladle water outlet and the top of the center pouring pipe. In the present invention, the height of the inner sleeve is 200 to 300 mm. If the height of the inner sleeve is too high, the distance between the ladle water outlet and the inner basin brick of the center pouring pipe increases, and the impact and erosion of the molten steel on the inner basin brick of the center pouring pipe during pouring increases. If the height of the inner sleeve is too low, it is not conducive to the formation of a stable flow of argon gas; two layers of upper and lower angled air outlet holes are provided on the conical surface of the inner sleeve. In order to achieve the guiding effect of the air outlet holes, the wall thickness of the inner sleeve is 20m to 60mm. This is because the air outlet holes that meet the directional requirements need to be processed on the inner sleeve. In order to achieve the guiding effect of the air outlet holes, the wall thickness of the inner sleeve should not be too small; but the wall thickness of the inner sleeve should not be too large. If the wall thickness is too large, it is difficult to roll it into a cylinder, and the argon protection ring is bulky, which is not conducive to installation.

[0060] Specifically, the inner cross-section of the inner sleeve is conical, and the inner diameter of the upper opening is D 上 , the inner diameter of the lower opening is D 下 When the steel ingot is cast using double-layer slide casting, the inner diameter D of the upper opening of the inner sleeve 上 Need to meet: D 上 ≥D 外 and D 上 ≥L+D 水 / 2; where D 外 is the outer diameter of the ladle nozzle refractory, L is the nozzle sliding stroke when using double-layer slide casting, D 水 The diameter of the ladle nozzle is in mm. When the three-layer slide plate is used for casting the steel ingot, the sliding stroke of the nozzle during the three-layer slide plate casting is L = 0 mm. The inner diameter of the lower opening of the inner sleeve is D 下 Need to meet: D 下 >D 砖 , where D 砖 D is the outer diameter of the basin brick in the center injection pipe; in order to facilitate the processing of the air hole in the inner sleeve, 下 The value should be as large as possible. Preferably, D 下 Equal to the inner diameter of the outer sleeve.

[0061] Specifically, the air outlet holes opened on the conical surface of the inner sleeve include upper air outlet holes and lower air outlet holes. The opening directions of the upper air outlet holes and the lower air outlet holes are different. The number of the upper air outlet holes and the lower air outlet holes is the same, both N, and the value range of N is 4 to 16; the upper air outlet holes and the lower air outlet holes are evenly distributed around the circumference of the inner sleeve, and the upper and lower air outlet holes are symmetrical. The angle between each pair of air outlet holes is 360° / N; preferably, the multiple air outlet holes are 8 pairs in the upper and lower layers, 16 in total, evenly distributed around a circle, and the angle between each pair of air outlet holes is 45°; the diameter of the air outlet holes is consistent with the inner diameter of the air inlet pipe, and the position of the air outlet holes is 1 to 5 mm away from the upper and lower end surfaces of the inner sleeve, so as to facilitate the processing and manufacturing of the air outlet holes. Preferably, the position of the air outlet holes is 1 mm away from the upper and lower end surfaces of the inner sleeve. Among them, the top surface of the inner sleeve is a horizontal plane, and the upper air outlet holes maintain an angle α with the horizontal plane. The size of the angle is determined by the diameter D of the air outlet holes. 孔 、Inner diameter of inner sleeve upper opening D 上 and the outer diameter D of the ladle nozzle refractory 外 Design; minimum value of α min Satisfaction: sinα min =2×D 孔 / (D 上 -D 外 ); The bottom end surface of the inner sleeve is a horizontal plane, and the lower air outlet maintains an angle β with the horizontal plane, the size of the angle is based on the diameter of the air outlet D 孔 、Inner diameter of the lower end of the inner sleeve D 下 , the outer diameter D of the basin brick in the injection pipe 砖 Design; minimum value of β min Satisfaction: sinβ min =2×D 孔 / (D 下 -D 砖 ); The angles α and β respectively determine the direction of the vent, ensuring good argon protection and positive pressure environment in the gas chamber, while avoiding direct impact on the molten steel stream, reducing the swing of the molten steel stream and the erosion of the molten steel on the refractory, and ensuring that the products produced by the steel ingot pass the ultrasonic inspection.

[0062] Specifically, the cover plate and the middle plate are made of steel plates with a thickness of 2 to 3 mm, ensuring that the cover plate and the middle plate have sufficient strength for reuse; the cover plate is an annular plate with a hole in the middle, and the outer diameter of the cover plate is equal to the outer diameter of the outer sleeve, and the inner diameter of the cover plate is equal to the inner diameter of the upper end of the inner sleeve. The middle plate is an annular plate with a hole in the middle, and the outer diameter of the middle plate is equal to the inner diameter of the outer sleeve, and is larger than the inner diameter of the lower end of the inner sleeve. The inner diameter of the middle plate is 10 to 20 mm larger than the outer diameter of the basin brick in the center injection pipe. The dimensions of the cover plate and the middle plate meet the requirements to ensure the sealing of the air chamber and ensure that the middle plate has enough area to fall on the top surface of the center injection pipe to achieve air chamber sealing; at the same time, it ensures that the basin brick can pass through the inner hole of the middle plate for easy assembly.

[0063] Specifically, the outer sleeve is equipped with four inlet pipes, each welded to the main pipe and the outer sleeve. The inlet pipes are evenly distributed around the outer sleeve, with a 90° angle between them. Furthermore, the four inlet pipes are staggered with the outlet holes on the inner sleeve, with each inlet pipe and the adjacent pair of outlet holes at an angle of 360° / 2N, where N ranges from 4 to 16. This angle prevents argon gas in the inlet pipes from directly impacting the outlet holes, which could result in higher argon pressure in some outlet holes than in others, affecting the uniform distribution of the positive pressure environment within the chamber. The inner diameter of the inlet pipes is equal to that of the vent pipe, ranging from 20 to 30 mm, with a wall thickness of 1 to 2 mm.

[0064] The present invention also provides a method for preparing an inner conical argon protection ring, which is used to prepare the inner conical argon protection ring, comprising:

[0065] S1: Design the size and shape of the main pipe, outer sleeve, inner sleeve, cover plate, middle plate, air inlet pipe, air outlet hole and vent pipe;

[0066] S2: According to the size and shape of the intake pipe and the vent pipe, the intake pipe and the vent pipe are made by processing thin-walled steel pipe;

[0067] S3: According to the size and shape of the outer sleeve and the inner sleeve, the outer sleeve and the inner sleeve are manufactured by rolling the steel plate;

[0068] S4: According to the size and shape of the cover plate and the middle plate, the cover plate and the middle plate are manufactured by processing the steel plate;

[0069] S5: According to the size and shape of the air outlet holes, process N pairs of air outlet holes at a distance of 1 to 5 mm from the upper and lower end surfaces of the inner sleeve, and keep the air outlet holes at an inclined angle to the horizontal plane;

[0070] S6: Weld the vent pipe to the main pipe, weld both ends of the air inlet pipe to the outside of the main pipe and the outer sleeve respectively, and connect the main pipe and the outer sleeve;

[0071] S7: The top surfaces of the inner sleeve and the outer sleeve are coplanar, and the cover plate is welded to the top surfaces of the outer sleeve and the inner sleeve;

[0072] S8: Weld the middle plate to the bottom end surface of the inner sleeve to form a gas chamber, thereby obtaining an inner conical argon protection ring.

[0073] Specifically, the sizes and shapes of the main pipe, outer sleeve, inner sleeve, cover plate, middle plate, air inlet pipe, air outlet hole, and vent pipe, and the inclination angles of the horizontal planes of the upper and lower ends of the air outlet hole and the inner sleeve need to meet the requirements as described above.

[0074] The argon protection ring prepared by the present invention is used in the atmospheric pouring steel ingot casting process, which includes the following steps:

[0075] S1: During pouring, the inner conical argon protection ring is nested on the middle pouring tube, and asbestos rings are provided on the top surfaces of the middle pouring tube and the argon protection ring;

[0076] S2: Argon enters the main pipe through the vent pipe of the conical argon protection ring, then enters the gas chamber through the inlet pipe, and then enters the surrounding of the molten steel stream through the outlet hole on the inner sleeve.

[0077] It should be noted that the ladle seat is on the casting car, the ladle nozzle is aligned with the center of the center pouring pipe during pouring, and the bottom of the ladle is compacted and sealed with the top surface of the argon protection ring; the asbestos ring avoids the rigid contact between the top surface of the center pouring pipe and the middle plate to produce a gap, which is more conducive to the formation of argon protection atmosphere and prevents air from entering.

[0078] Example 1

[0079] This embodiment relates to the design and use of an inner conical argon protection ring for 61-104 ton atmospheric casting steel ingots.

[0080] Refer to the attached diagram for the inner conical argon protection ring. Figures 1 to 3 .

[0081] In this embodiment, the outer diameter of the injection pipe used is D 中注管 500mm; the outer diameter of the basin brick used is D 砖 320mm; outer diameter of ladle nozzle refractory material D 外 170mm; ladle nozzle diameter D 水 The sliding stroke of the gate for double-layer sliding plate casting is L, which is 150mm.

[0082] In this embodiment, the size and shape of the inner conical argon protection ring are designed as follows:

[0083] S1: Design the size and shape of the main pipe, outer sleeve, inner sleeve, cover plate, middle plate, air inlet pipe, air outlet hole and vent pipe;

[0084] S2: According to the size and shape of the intake pipe and the vent pipe, the intake pipe and the vent pipe are made by processing thin-walled steel pipe;

[0085] The outer diameter of the vent pipe and the intake pipe is 32mm, the inner diameter is 30mm, and the wall thickness is 1mm.

[0086] S3: According to the size and shape of the outer sleeve and the inner sleeve, the outer sleeve and the inner sleeve are manufactured by rolling the steel plate;

[0087] Among them, the outer sleeve height H 外 The inner sleeve is 450mm (1.96 times the height of the inner sleeve), the inner diameter of the outer sleeve is 520mm (20mm larger than the outer diameter of the middle injection pipe of 500mm), the wall thickness is 3mm, and the outer diameter of the outer sleeve is 526mm; the inner sleeve height H 内230mm, wall thickness 20mm, inner diameter of inner sleeve upper end D 上 330mm, inner diameter of the inner sleeve bottom D 下 420mm; the inner diameter of the outer sleeve is 10 to 25mm larger than the outer diameter of the middle injection pipe, and the height of the outer sleeve is designed to be 1.5 to 2.0 times the height of the inner sleeve.

[0088] S4: According to the size and shape of the cover plate and the middle plate, the cover plate and the middle plate are manufactured by processing the steel plate;

[0089] The cover plate has an outer diameter of 523mm, an inner diameter of 330mm, and a wall thickness of 3mm; the middle plate has an outer diameter of 520mm, an inner diameter of 340mm, and a wall thickness of 3mm. The outer diameter of the cover plate is equal to that of the outer sleeve, and the inner diameter of the cover plate is equal to the inner diameter of the upper opening of the inner sleeve. The outer diameter of the middle plate is equal to the inner diameter of the outer sleeve, and the inner diameter of the middle plate is 10-20mm larger than the outer diameter of the basin brick inside the center injection pipe.

[0090] S5: According to the size and shape of the vent holes, 8 vent holes are machined at 3mm from the upper and lower end surfaces of the inner sleeve, for a total of 8 pairs of 16 holes, evenly distributed around the inner sleeve. The angle between each pair of vent holes is 45°, and the vent hole diameter is D 孔 =30mm; the upper air outlet maintains an angle α with the horizontal plane, α=30°, and the lower air outlet maintains an angle β with the horizontal plane, β=80°. Satisfy α>α min ,β>β min Among them, sinα min =2×D 孔 / (D 上 -D 外 )=0.375,α min＝ 22°; sinβ min =2×D 孔 / (D 下 -D 砖 )=0.6,β min =36.87°.

[0091] S6: Weld the vent pipe to the main pipe, weld the two ends of the intake pipe to the main pipe and the outside of the outer sleeve respectively, and connect the main pipe and the outer sleeve; wherein the intake pipes are evenly distributed around the outer sleeve, and the angle between the intake pipes is 90°. The intake pipes and the air outlet holes on the inner sleeve are staggered, and the angle between each intake pipe and the adjacent pair of air outlet holes is 22.5° (i.e., 360° / 2N=360° / 16=22.5°);

[0092] S7: The top surfaces of the inner sleeve and the outer sleeve are coplanar, and the cover plate is welded to the top surfaces of the outer sleeve and the inner sleeve;

[0093] S8: Weld the middle plate to the bottom end surface of the inner sleeve to form a gas chamber, thereby obtaining an inner conical argon protection ring.

[0094] During the pouring process, the inner conical argon protection ring is nested on the middle pouring pipe, and asbestos rings are provided on the top surfaces of the middle pouring pipe and the argon protection ring. The argon enters the main pipe through the vent pipe of the conical argon protection ring, then enters the air chamber through the air inlet pipe, and then enters the surrounding of the molten steel stream through the air outlet hole on the inner sleeve.

[0095] During refining and tapping, the gas contents in the molten steel were measured to be 0.8 ppm H, 21 ppm O, and 45 ppm N. After pouring, Tangdao Steel sampled the steel and measured the gas contents to be 1.1 ppm H, 24 ppm O, and 49 ppm N. The gas contents of the final steel ingot were 0.9 ppm H, 19 ppm O, and 44 ppm N. Compared to the gas contents in the ingot at tapping, the gas contents in the final steel ingot increased by 0.1 ppm H, decreased by 2 ppm O, and decreased by 1 ppm N. This demonstrates that in this embodiment, the gas content in the steel is controlled, effectively ensuring product quality. Furthermore, the product produced from this ingot passed ultrasonic testing.

[0096] Example 2

[0097] This embodiment relates to the design and use of an inner conical argon protection ring for 80-130 ton atmospheric casting steel ingots.

[0098] Refer to the attached diagram for the inner conical argon protection ring. Figures 1 to 3 .

[0099] In this embodiment, the outer diameter of the injection pipe used is D 中注管 726mm; the outer diameter of the basin brick used is D 砖 370mm; outer diameter of ladle nozzle refractory material D 外 170mm; ladle nozzle diameter D 水 The sliding stroke of the gate for double-layer sliding plate casting is L, which is 150mm.

[0100] In this embodiment, the size and shape of the inner conical argon protection ring are designed as follows:

[0101] S1: Design the size and shape of the main pipe, outer sleeve, inner sleeve, cover plate, middle plate, air inlet pipe, air outlet hole and vent pipe;

[0102] S2: According to the size and shape of the intake pipe and the vent pipe, the intake pipe and the vent pipe are made by processing thin-walled steel pipe;

[0103] The outer diameter of the vent pipe and the intake pipe is 32mm, the inner diameter is 30mm, and the wall thickness is 1mm;

[0104] S3: According to the size and shape of the outer sleeve and the inner sleeve, the outer sleeve and the inner sleeve are manufactured by rolling the steel plate;

[0105] Among them, the outer sleeve height H 外 550mm (1.83 times the height of the inner sleeve), the inner diameter of the outer sleeve is 746mm (20mm larger than the outer diameter of the middle injection pipe 726mm), the wall thickness is 3mm, the outer diameter of the outer sleeve is 752mm; the inner sleeve height H 内 300mm, wall thickness 30mm, inner diameter of inner sleeve upper end D 上 330mm, inner diameter of the inner sleeve bottom D 下 622mm; the inner diameter of the outer sleeve is 10 to 25mm larger than the outer diameter of the middle injection pipe; the height of the outer sleeve is designed to be 1.5 to 2.0 times the height of the inner sleeve.

[0106] S4: According to the size and shape of the cover plate and the middle plate, the cover plate and the middle plate are manufactured by processing the steel plate;

[0107] The cover plate has an outer diameter of 752mm, an inner diameter of 330mm, and a wall thickness of 3mm; the middle plate has an outer diameter of 746mm, an inner diameter of 390mm, and a wall thickness of 3mm. The outer diameter of the cover plate is equal to that of the outer sleeve, and the inner diameter of the cover plate is equal to the inner diameter of the upper opening of the inner sleeve. The outer diameter of the middle plate is equal to the inner diameter of the outer sleeve, and the inner diameter of the middle plate is 10-20mm larger than the outer diameter of the basin brick inside the center injection pipe.

[0108] S5: According to the size and shape of the vent holes, 8 vent holes are machined at 5mm from the upper and lower end surfaces of the inner sleeve, for a total of 8 pairs of 16 holes, evenly distributed around the inner sleeve. The angle between each pair of vent holes is 45°, and the vent hole opening diameter is D 孔 =30mm; the upper air outlet maintains an angle α with the horizontal plane, α=23°, and the lower air outlet maintains an angle β with the horizontal plane, β=36°. Satisfy α>α min ,β>β min Among them, sinα min =2×D 孔 / (D 上 -D 外 )=0.375,α min＝ 22°; sinβ min =2×D 孔 / (D 下 -D 砖 )=0.238,β min =15.3°.

[0109] S6: Weld the vent pipe to the main pipe, weld the two ends of the intake pipe to the main pipe and the outside of the outer sleeve respectively, and connect the main pipe and the outer sleeve; wherein the intake pipes are evenly distributed around the outer sleeve, and the angle between the intake pipes is 90°. The intake pipes and the air outlet holes on the inner sleeve are staggered, and the angle between each intake pipe and the adjacent pair of air outlet holes is 22.5° (i.e., 360° / 2N=360° / 16=22.5°);

[0110] S7: The top surfaces of the inner sleeve and the outer sleeve are coplanar, and the cover plate is welded to the top surfaces of the outer sleeve and the inner sleeve;

[0111] S8: Weld the middle plate to the bottom end surface of the inner sleeve to form a gas chamber, thereby obtaining an inner conical argon protection ring.

[0112] During the pouring process, the inner conical argon protection ring is nested on the middle pouring pipe, and asbestos rings are provided on the top surfaces of the middle pouring pipe and the argon protection ring. The argon enters the main pipe through the vent pipe of the conical argon protection ring, then enters the air chamber through the air inlet pipe, and then enters the surrounding of the molten steel stream through the air outlet hole on the inner sleeve.

[0113] During refining and tapping, the gas contents in the molten steel were measured as H: 0.9ppm, O: 25ppm, and N: 63ppm. After pouring, Tangdao Steel took samples and measured the gas contents in the steel as H: 1.0ppm, O: 22ppm, and N: 57ppm. The gas contents of the final steel ingot product prepared were H: 1.1ppm, O: 23ppm, and N: 62ppm. Compared with the gas contents in the steel ingot during tapping, the gas content of the final steel ingot product prepared was 0.2ppm higher in H content, 2ppm lower in O content, and 1ppm lower in N content. It can be seen that in this embodiment, the gas in the steel is controlled, effectively ensuring product quality. The products produced by this steel ingot passed ultrasonic testing.

[0114] Comparative Example 1

[0115] This comparative example involves 61-104 ton atmospheric casting steel ingots (same as Example 1), and the use of an existing ordinary argon protection ring.

[0116] The inner and outer sleeves of the existing common argon protection ring are both cylindrical. Figure 4 .

[0117] In this comparative example, the outer diameter of the injection pipe used is D 中注管 500mm; the outer diameter of the basin brick used is D 砖 320mm; outer diameter of ladle nozzle refractory material D 外 170mm; ladle nozzle diameter D 水 The sliding stroke of the gate for double-layer sliding plate casting is L, which is 150mm.

[0118] In this comparative example, the size and shape of the ordinary argon protection ring are as follows: the outer sleeve and inner sleeve of the argon protection ring are both cylindrical, the outer sleeve has an inner diameter of 520mm, a wall thickness of 3mm, and an outer sleeve outer diameter of 526mm; the inner sleeve has an inner diameter of 350mm, a wall thickness of 20mm, and an inner sleeve outer diameter of 390mm.

[0119] During the pouring process, an ordinary argon protection ring is nested on the middle pouring pipe; the argon enters the gas chamber through the inlet pipe, and then enters the surrounding of the molten steel stream through the outlet holes on the inner sleeve.

[0120] During refining and tapping, the gas content of the molten steel was measured as H: 1.0ppm, O: 25ppm, and N: 68ppm; after pouring, Tangdao Steel was sampled and the gas content in the steel was measured as H: 1.5ppm, O: 29ppm, and N: 69ppm; the gas content of the finally prepared steel ingot product was H: 1.8ppm, O: 28ppm, and N: 76ppm. Compared with the gas content in the steel ingot during tapping, the gas content of the finally prepared steel ingot product increased by 0.8ppm, the O content increased by 3ppm, and the N content decreased by 8ppm. The fluctuation value of the H content in this comparative example is much greater than that in Example 1 and Example 2. It can be seen that in this comparative example, the gas content in the steel is not effectively controlled.

[0121] Comparative Example 2

[0122] This embodiment relates to the design and use of an inner conical argon protection ring for 61-104 ton atmospheric casting steel ingots.

[0123] Refer to the attached diagram for the inner conical argon protection ring. Figures 1 to 3 .

[0124] In this embodiment, the outer diameter of the injection pipe used is D 中注管 500mm; the outer diameter of the basin brick used is D 砖 320mm; outer diameter of ladle nozzle refractory material D 外 170mm; ladle nozzle diameter D 水 The sliding stroke of the gate for double-layer sliding plate casting is L, which is 150mm.

[0125] In this embodiment, the size and shape of the inner conical argon protection ring are designed as follows:

[0126] S1: Design the size and shape of the main pipe, outer sleeve, inner sleeve, cover plate, middle plate, air inlet pipe, air outlet hole and vent pipe;

[0127] S2: According to the size and shape of the intake pipe and the vent pipe, the intake pipe and the vent pipe are made by processing thin-walled steel pipe;

[0128] The outer diameter of the vent pipe and the intake pipe is 32mm, the inner diameter is 30mm, and the wall thickness is 1mm.

[0129] S3: According to the size and shape of the outer sleeve and the inner sleeve, the outer sleeve and the inner sleeve are manufactured by rolling the steel plate;

[0130] Among them, the outer sleeve height H 外322mm (1.4 times the height of the inner sleeve), the inner diameter of the outer sleeve is 520mm, the wall thickness is 3mm, the outer diameter of the outer sleeve is 526mm; the inner sleeve height H 内 230mm, wall thickness 20mm, inner diameter of inner sleeve upper end D 上 330mm, inner diameter of the inner sleeve bottom D 下 420mm; the inner diameter of the outer sleeve is 10 to 25mm larger than the outer diameter of the middle injection pipe; the requirement that the height of the outer sleeve is designed to be 1.5 to 2.0 times the height of the inner sleeve is not met.

[0131] S4: According to the size and shape of the cover plate and the middle plate, the cover plate and the middle plate are manufactured by processing the steel plate;

[0132] The cover plate has an outer diameter of 523mm, an inner diameter of 330mm, and a wall thickness of 3mm; the middle plate has an outer diameter of 520mm, an inner diameter of 340mm, and a wall thickness of 3mm. The outer diameter of the cover plate is equal to that of the outer sleeve, and the inner diameter of the cover plate is equal to the inner diameter of the upper opening of the inner sleeve. The outer diameter of the middle plate is equal to the inner diameter of the outer sleeve, and the inner diameter of the middle plate is 10-20mm larger than the outer diameter of the basin brick inside the center injection pipe.

[0133] S5: According to the size and shape of the vent holes, 8 vent holes are machined at 3mm from the upper and lower end surfaces of the inner sleeve, for a total of 8 pairs of 16 holes, evenly distributed around the inner sleeve. The angle between each pair of vent holes is 45°, and the vent hole diameter is D 孔 =30mm; the upper air outlet maintains an angle α with the horizontal plane, α=5°, β=10°; not satisfied: α>α min ,β>β min ; Among them, sinα min =2×D 孔 / (D 上 -D 外 )=0.375,α min＝ 22°; sinβ min =2×D 孔 / (D 下 -D 砖 )=0.6,β min =36.87°.

[0134] S6: Weld the vent pipe to the main pipe, weld the two ends of the intake pipe to the main pipe and the outside of the outer sleeve respectively, and connect the main pipe and the outer sleeve; wherein the intake pipes are evenly distributed around the outer sleeve, and the angle between the intake pipes is 90°. The intake pipes and the air outlet holes on the inner sleeve are staggered, and the angle between each intake pipe and the adjacent pair of air outlet holes is 22.5° (i.e., 360° / 2N=360° / 16=22.5°);

[0135] S7: The top surfaces of the inner sleeve and the outer sleeve are coplanar, and the cover plate is welded to the top surfaces of the outer sleeve and the inner sleeve;

[0136] S8: Weld the middle plate to the bottom end surface of the inner sleeve to form a gas chamber, thereby obtaining an inner conical argon protection ring.

[0137] During the pouring process, the inner conical argon protection ring is nested on the middle pouring pipe, and asbestos rings are provided on the top surfaces of the middle pouring pipe and the argon protection ring. The argon enters the main pipe through the vent pipe of the conical argon protection ring, then enters the air chamber through the air inlet pipe, and then enters the surrounding of the molten steel stream through the air outlet hole on the inner sleeve.

[0138] During refining and tapping, the gas content of the molten steel was measured as H: 1.0ppm, O: 22ppm, and N: 41ppm; after pouring, Tangdao Steel took a sample and measured the gas content in the steel as H: 1.3ppm, O: 24ppm, and N: 65ppm; the gas content of the finally prepared steel ingot product was H: 1.4ppm, O: 23ppm, and N: 65ppm. Compared with the gas content in the steel ingot during tapping, the gas content of the finally prepared steel ingot product increased by 0.4ppm in H content, 1ppm in O content, and 24ppm in N content. The fluctuation value of the H content in this comparative example is much greater than that in Example 1 and Example 2. It can be seen that in this comparative example, the gas content in the steel is not effectively controlled.

[0139] It can be seen from Examples 1 and 2 and Comparative Example 1 that the inner conical inner sleeve reduces the size of the argon outlet, which significantly promotes the maintenance of a positive argon pressure environment around the molten steel stream, effectively prevents external air from entering the molten steel stream, and better controls the molten steel suction effect.

[0140] As shown in Examples 1 and 2 and Comparative Example 2, the inner tapered argon protection ring used in Comparative Example 2 weakens the argon seal because the outlet holes are not oriented toward the argon outlet. Furthermore, the argon gas impacts the molten steel stream, causing it to oscillate and increase molten steel corrosion on the refractory. This increases foreign inclusions in the steel ingot and causes problems with ultrasonic flaw detection.

[0141] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. An inner conical argon protection ring, characterized in that: The inner conical argon protection ring comprises an inner sleeve, an outer sleeve and a main pipe which are sequentially sleeved from the inside to the outside; The main pipe is a hollow annular pipe and is connected to the outer sleeve through the air inlet pipe; The inner sleeve is a conical hollow sleeve, which is connected to the outer sleeve through the air outlet hole opened on the conical surface; The top ends of the inner sleeve and the outer sleeve are connected by a cover plate, and the bottom end of the inner sleeve is connected to the inner wall of the outer sleeve through a middle plate. The outer wall of the inner sleeve, the inner wall of the outer sleeve, the lower end surface of the cover plate and the upper end surface of the middle plate together form an air chamber; The air outlet holes opened on the conical surface of the inner sleeve include upper air outlet holes and lower air outlet holes, and the upper air outlet holes and the lower air outlet holes have different opening directions; The top surface of the inner sleeve is a horizontal plane, and the upper air outlet maintains an angle α with the top surface of the inner sleeve, and the minimum value of α is α min Satisfaction: sinα min =2×D 孔 / (D 上 -D 外 ); The bottom end surface of the inner sleeve is a horizontal plane, and the lower air outlet hole maintains an angle β with the horizontal plane of the bottom end surface of the inner sleeve, and the minimum value β min Satisfaction: sinβ min =2×D 孔 / (D 下 -D 砖 ); Wherein, α is the angle between the upper air outlet and the horizontal plane of the top surface of the inner sleeve, degrees; β is the angle between the lower air outlet and the horizontal plane of the bottom end surface of the inner sleeve, degrees; D 孔 is the diameter of the air outlet, mm; D 上 is the inner diameter of the upper opening of the inner sleeve, mm; D 外 is the outer diameter of the ladle nozzle refractory, mm; D 下 is the inner diameter of the lower opening of the inner sleeve, mm; D 砖 is the outer diameter of the basin brick inside the center injection pipe, mm.

2. The inner conical argon protection ring according to claim 1, characterized in that: The number of the upper and lower air outlet holes is the same, both N, and the value of N ranges from 4 to 16; The upper air outlet holes and the lower air outlet holes are evenly distributed around the circumference of the inner sleeve.

3. The inner conical argon protection ring according to claim 2, characterized in that: The upper air outlet holes are 1-5 mm away from the top end surface of the inner sleeve, and the lower air outlet holes are 1-5 mm away from the bottom end surface of the inner sleeve.

4. The inner conical argon protection ring according to claim 1, characterized in that: The cover plate is an annular plate with a hole in the middle, and the outer diameter of the cover plate is equal to the outer diameter of the outer sleeve.

5. The inner conical argon protection ring according to claim 1, characterized in that: The height of the outer sleeve is 1.5 to 2.0 times the height of the inner sleeve.

6. The inner conical argon protection ring according to claim 1, characterized in that: When the steel ingot is cast using double-layer slide casting, the inner sleeve meets the following requirements: 上 ≥D 外 and D 上 ≥L+D 水 / 2; Among them, D 上 is the inner diameter of the upper opening of the inner sleeve, mm; D 外 is the outer diameter of the ladle nozzle refractory, mm; L is the sliding stroke of the nozzle when using double-layer slide casting, mm; D 水 is the diameter of the ladle nozzle, mm; When the steel ingot is cast using three-layer slide casting, the inner sleeve meets the following requirements: 下 >D 砖 ; Among them, D 下 is the inner diameter of the lower opening of the inner sleeve, mm; D 砖 is the outer diameter of the basin brick inside the center injection pipe, mm.

7. A method for preparing an inner conical argon protection ring, characterized in that: Used to prepare the inner conical argon protection ring according to any one of claims 1 to 6.

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