Self-cleaning argon blowing stopper rod for improving nozzle nodulation and continuous casting and continuous casting gas supply method

Abstract

The invention discloses a self-cleaning argon blowing stopper rod for improving nozzle nodulation and a continuous casting and continuous casting gas supply method. The argon blowing stopper rod comprises a stopper rod body, a circular seam gas channel and a stopper rod head. The bottom of the stopper rod body is connected with the stopper rod head, and one end, far away from the stopper rod head, of the stopper rod body is provided with a gas connecting joint connected with a gas supply pipeline; the circular seam gas channel is arranged in the stopper rod body; a gas inlet at one end of the circular seam gas channel is connected with the gas connector, and a circular seam outlet at the other end of the circular seam gas channel is arranged on the stopper rod head; and a rotary strip rib partition structure is arranged between the outer wall and the inner wall of the circular seam gas channel. The argon blowing channel structure of the stopper rod is optimized, the stopper rod head is cleaned through rotating airflow formed by the circular seam gas channel, nodulation at the nozzle bowl opening is reduced, and therefore the inclusion nodulation state and the continuous casting state of the nozzle bowl part and the inner wall are improved, and the molten steel quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of iron and steel metallurgy, and more specifically, to a self-cleaning argon-blowing stopper for improving nozzle nodulation and a continuous casting and continuous pouring gas supply method. Background Art

[0002] Nozzle nodulation often occurs at the head of the stopper rod and the submerged nozzle during continuous casting, especially nodulation in the submerged nozzle is the most common. Nozzle nodulation not only affects the smooth progress of continuous casting pouring, reducing the pouring efficiency, but also is a main cause of slab quality problems.

[0003] When pouring aluminum-killed steel, deoxidation products adhere to the head of the stopper rod and the inner wall of the nozzle. The inlet and outlet of the nozzle are the main positions where inclusions adhere, especially the part below the slag line. In addition to iron, the nodulation substances mainly consist of Al2O3, and there are also MgO and MnO, etc. Due to the attachment and deposition of nodulation substances such as Al2O3 on the head of the stopper rod and the inner wall of the nozzle, the inner cavity of the nozzle shrinks, the molten steel flow rate is unstable, resulting in uneven flow and violent fluctuations in the mold liquid level, causing quality problems on the surface of the slab. The molten steel flow will also entrain the nodulation substances washed and peeled off into the liquid phase of the mold, forming inclusions with larger particles, and finally forming quality defects of the slab; especially during the pouring process in the later stage of continuous pouring, when the nodulation of the stopper rod is severe to a certain extent, it will lead to out-of-control molten steel, a sharp drop in the mold liquid level, and it is impossible to continue pouring steel. It is necessary to end the pouring in advance, which will affect the continuity of pouring, reduce the number of continuous casting heats, affect the continuous casting efficiency, and increase the production cost.

[0004] In order to prevent nozzle nodulation, the existing process is to use the stopper rod argon-blowing method during continuous casting pouring to improve the nozzle pouring state. By opening an argon channel inside the stopper rod to blow argon into the molten steel at a certain pressure and flow rate, the argon channel is a straight through hole with a certain diameter opened along the axis of the stopper rod, and the channel diameter is reduced at the head of the stopper rod, that is, the argon outlet part, to realize blowing argon during the pouring process, prevent inclusions from nodulating at the inlet bowl and inner wall of the nozzle during continuous casting pouring, and avoid nozzle blockage. In the argon-blowing stopper rod, the currently commonly used gas supply structure forms are divided into single-hole type, multi-hole type, and diffused argon-blowing stopper rod, that is, single or multiple guide air holes are opened on the head of the stopper rod, and these guide air holes are connected to the argon channel in the stopper rod body.

[0005] CN202010732290.4 discloses a high-quality steel continuous casting argon-blowing stopper, an argon-blowing stopper system and an argon-blowing method. The gas passage in the argon-blowing stopper includes a main passage, a diffusion gas chamber and a slit-type passage. The main passage is arranged on the central axis of the stopper body. One end of the main passage is connected to the gas supply pipeline, and the other end of the main passage communicates with a plurality of slit-type passages through the diffusion gas chamber. The outlets of the plurality of slit-type passages are diffusely arranged on the bottom surface of the stopper head. In this argon-blowing system, the displacement sensor for detecting the displacement of the stopper is connected to the flow control valve for controlling the argon gas flow through a PLC. This technology improves the size and distribution state of the argon gas bubbles entering the molten steel, and dynamically adjusts the argon gas flow in the stopper according to the actual casting process, effectively improving the inclusion nodulation state in the nozzle bowl and inner wall and the continuous casting state, and improving the quality of the molten steel.

[0006] CN202010875419.7 provides an argon-blowing stopper and its manufacturing method, including: a through cavity is provided through the center position of the inner layer of the stopper head; one end of the through cavity communicates with the inner cavity, and the other end communicates with the argon gas flow passage; the stopper head is conical, and the formed argon gas flow passage is arc-shaped; the argon gas flow passage is annular and is arranged around the central axis of the rod body; or, the argon gas flow passage is in multiple groups and is spaced around the central axis of the rod body, and the passage is arranged at the inner layer of the stopper head, one end communicates with the through cavity, and the other end communicates with the argon gas flow passage. The stopper of this technology has the argon-blowing function and can effectively improve the resistance to molten steel erosion.

[0007] CN202210586388.2 discloses a continuous casting argon-blowing stopper and its preparation method and application. The stopper head at the front end of the stopper is made of a mesoporous material; two or more spherical gas chambers adjacent to each other in the vertical direction and connected to the tubular argon gas passage are provided inside the stopper head, and the volume of each spherical gas chamber gradually decreases from top to bottom. An erosion-resistant layer is distributed circumferentially on the outer side wall at the connection between the stopper body and the stopper head. This stopper can completely eliminate the problem of concentrated argon blowing, ensure that the argon gas with stable flow is diffusely blown into the molten steel to form small and uniform bubbles, so as to eliminate the influence of large bubbles on the liquid level fluctuation in the mold, and effectively remove the flocculent inclusions at the stopper head, improve the flow control accuracy, enhance the argon-blowing effect, and purify the quality of the molten steel.

[0008] Overall, the existing argon blowing treatment methods play a good role in preventing nozzle caking and clogging, but there are also problems: (1) There are certain limitations in the design of the argon gas channel inside the stopper rod. When continuously casting multiple furnaces of non-calcium treated steel grades, as the casting time increases, inclusions in the molten steel accumulate continuously in the area of the stopper rod head and the nozzle bowl. Even with argon blowing through the stopper rod, they cannot be eliminated, and the "rod flushing" action is required to shake off the caking substances; (2) Some porous material gas permeable plugs are used in the area of the stopper rod head. Due to the high resistance loss of the porous structure, a relatively high operating pressure is required. In the case of low gas source pressure, it is easy to clog and difficult to reopen. Moreover, after long-term erosion by the molten steel, the rod head is prone to loosen and fall off; (3) The argon blowing flow rate during the existing casting process is constant, or only starts to adjust the argon blowing flow rate after a set time period, making the argon blowing flow rate not fully adapt to the actual casting conditions. Summary of the Invention

[0009] Aiming at the defects existing in the prior art, the purpose of the present invention is to provide a self-cleaning argon blowing stopper rod for improving nozzle caking and a continuous casting and continuous pouring gas supply method, which optimizes the argon blowing channel structure of the stopper rod, uses the rotating air flow formed by the annular gap gas channel to clean the stopper rod head, reduces caking at the nozzle bowl opening, thereby improving the caking state of inclusions at the nozzle bowl and inner wall, adapting to the continuous casting long continuous pouring process, and improving the quality of molten steel.

[0010] To achieve the above purpose, the present invention adopts the following technical solutions:

[0011] The first aspect of the present invention provides a self-cleaning argon blowing stopper rod for improving nozzle caking, including a stopper rod body, an annular gap gas channel, and a stopper rod head;

[0012] The bottom of the stopper rod body is connected to the stopper rod head, and a gas connection joint connected to the gas supply pipeline is provided at one end of the stopper rod body far from the stopper rod head;

[0013] The annular gap gas channel is arranged inside the stopper rod body; one end of the annular gap gas channel, the gas inlet, is connected to the gas connection joint, and the other end, the annular gap outlet, is arranged on the stopper rod head; a rotating strip rib partition structure is provided between the outer wall and the inner wall of the annular gap gas channel.

[0014] Preferably, the rotating strip rib partition structure includes multiple spiral strip rib partitions, and each spiral strip rib partition includes a straight section arranged at the upper part of the annular gap gas channel and a spiral section arranged at the lower part of the annular gap gas channel; the spiral section is connected to the straight section.

[0015] Preferably, the spiral section is spiral with respect to the central vertical axis of the stopper rod body, and the end of the spiral section extends to the annular gap outlet of the annular gap gas channel.

[0016] Preferably, the angle θ between the end of the spiral section and the vertical axis is 40 to 60°.

[0017] The second aspect of the present invention provides a continuous casting and continuous pouring gas supply method, which uses the self-cleaning argon-blowing stopper rod for improving nozzle nodulation as described in the first aspect of the present invention, and includes the following steps:

[0018] S1. When starting the casting of the ladle and the molten steel flows into the tundish, turn on the argon gas source, supply argon gas into the annular gap gas channel of the argon-blowing stopper rod, and control the argon gas flow rate to be 5.5 NL / min to 6.5 NL / min;

[0019] S2. During the casting process, adjust the argon gas flow rate according to the weight of the molten steel in the tundish and the current casting speed;

[0020] S3. At the end of the casting sequence, when the weight of the molten steel in the tundish is less than 30 t, adjust the supplied argon gas flow rate until the casting is completed.

[0021] Preferably, in the step S1, the continuous supply time of the argon gas is 5 to 10 min.

[0022] Preferably, in the step S2:

[0023] When the weight of the molten steel in the tundish ≥ 30 t, adjust the argon gas flow rate according to the current casting speed;

[0024] When the casting speed > 1 m / min, adjust the argon gas flow rate to 4.5 to 6 NL / min;

[0025] When the casting speed ≤ 1 m / min, adjust the argon gas flow rate to 3 to 4.5 NL / min.

[0026] Preferably, in the step S3, the argon gas flow rate is 3 to 5 NL / min.

[0027] Advantages of the present invention:

[0028] 1. By improving the gas channel in the continuous casting argon-blowing stopper rod, an annular gap gas channel is provided in the stopper rod body, which has an annular gap swirling structure. The gas supply structure does not require internal mechanical movement, and only uses the spatial structure to promote the rotational flow of the gas; when the gas rotates and flows out from the stopper head, it drives the surrounding molten steel flow to scour and clean the stopper head and the nozzle bowl. Therefore, it can effectively prevent the inclusions carried by the flowing molten steel from adhering, aggregating and growing on the stopper head and the nozzle bowl;

[0029] 2. The present invention designs the stopper gas supply method during continuous casting and continuous pouring. That is, during normal casting, phased control is adopted according to the casting start situation, the molten steel weight in the tundish, and the dynamic change of the drawing speed, and the argon blowing flow rate is adjusted in real time and dynamically to ensure that an appropriate gas carrying capacity per ton of steel is blown into the nozzle, effectively improving the inclusion nodulation state at the nozzle bowl and inner wall and the continuous casting state, and improving the quality of molten steel.

[0030] 3. The self-cleaning argon-blowing stopper for improving nozzle nodulation of the present invention has a simple structure, stable gas outlet, and long service life; the channel structure of the stopper argon blowing is optimized, and the rotating air flow formed by the annular gap gas channel is used to clean the stopper head, reducing the nodulation blockage at the nozzle bowl opening, ensuring the stability of the gas entering the mold nozzle, giving full play to the role of argon bubbles in adsorbing and removing inclusions and improving nozzle nodulation, and dynamically adjusting the argon gas flow rate according to the actual casting process, so that the blown argon gas volume adapts to the current pouring situation, effectively improving the inclusion nodulation state at the nozzle bowl and inner wall and the continuous casting state, and improving the quality of molten steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic structural diagram of the self-cleaning argon-blowing stopper for improving nozzle nodulation of the present invention;

[0032] Figure 2 is a schematic structural diagram of the annular gap gas channel of the present invention;

[0033] Figure 3 is a schematic structural diagram of the spiral ribs in the annular gap gas channel of the present invention;

[0034] In the figure, 1 is the stopper body, 2 is the annular gap gas channel; 21 is the outer wall; 22 is the inner wall; 23 is the spiral rib partition; 231 is the straight section; 232 is the spiral section; 233 is the end; 3 is the stopper head; 4 is the gas connection joint; K is the vertical axis. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] In order to better understand the above technical solutions of the present invention, the technical solutions of the present invention will be further described below with reference to the drawings and embodiments.

[0036] Combined with Figure 1 As shown, a self-cleaning argon-blowing stopper for improving nozzle nodulation provided by the present invention

[0037] includes a stopper body 1, an annular gap gas channel 2, and a stopper head 3; the bottom of the stopper body 1 is connected to the stopper head 3, and a gas connection joint 4 connected to the gas supply pipeline is provided at one end of the stopper body 1 away from the stopper head 3, which is convenient for the quick installation and disassembly of the gas supply pipeline. Combined with Figure 2As shown in the figure, the annular gap gas channel 2 is arranged inside the stopper body 1; the gas inlet at one end of the annular gap gas channel 1 is connected to the gas connection joint 4, and the annular gap outlet at the other end is arranged on the stopper head 3; a rotating rib partition structure is arranged between the outer wall 21 and the inner wall 22 of the annular gap gas channel 2.

[0038] Combined with Figure 2 As shown in the figure, the rotating rib partition structure includes a plurality of spiral rib partitions 23; combined with Figure 3 As shown in the figure, each spiral rib partition 23 includes a straight section 231 arranged in the upper part of the annular gap gas channel 2 and a spiral section 232 arranged in the lower part of the annular gap gas channel 2; the spiral section 232 is connected to the straight section 231. Combined with Figure 3 As shown in the figure, the spiral section 232 is spiral with respect to the central vertical axis K of the stopper body 1, and the end 233 of the spiral section 232 extends to the annular gap outlet of the annular gap gas channel 2 (i.e., the slotted part of the stopper head 3).

[0039] Combined with Figure 3 As shown in the figure, the included angle θ between the end 233 of the spiral section 232 and the vertical axis K is 40 - 60°.

[0040] The self-cleaning argon-blowing stopper for improving nozzle nodulation of the present invention makes full use of the physical characteristics of the annular gap gas channel 2. The biggest feature of this structure is that there are no moving parts, and the unidirectional rotational flow of the fluid is realized only through the design of the flow channel. The principle is as follows: when the gas flows out from the stopper head 3, due to the guiding action of the spiral rib partition 23, the air flow rotates, and at the same time drives the nearby molten steel flow to rotate, forming a scouring and cleaning effect on the stopper head 3 and the nozzle bowl part. Therefore, it can effectively prevent the inclusions carried by the molten steel flow passing through the nozzle inlet from adhering, aggregating and growing on the stopper head 3 and the nozzle bowl part.

[0041] The present invention provides a continuous casting and continuous pouring gas supply method. By studying the relationship between the slag inclusion defect of the hot-rolled coil and the continuous casting argon-blowing flow rate under different casting speeds, it is found that the generation of the slag inclusion defect of the hot-rolled coil shows a relatively obvious law with the continuous casting argon-blowing flow rate. Under the condition of low casting speed, a relatively small argon-blowing flow rate is more likely to cause the appearance of slag inclusion defects, while under the condition of high casting speed, a relatively large argon-blowing flow rate is more likely to cause the appearance of slag inclusion defects. Therefore, the present invention adopts the above-mentioned self-cleaning argon-blowing stopper for improving nozzle nodulation, and after a large number of experimental comparisons, an appropriate argon-blowing method is optimized, and the continuous casting argon-blowing flow rate is adjusted according to the actual casting process, effectively ensuring the stability of the gas entering the nozzle, improving the inclusion nodulation state of the stopper head and the nozzle bowl part and the continuous casting state, and improving the molten steel quality.

[0042] The continuous casting and continuous pouring gas supply method of the present invention uses the self-cleaning argon blowing stopper rod for improving nozzle nodulation as described above. During continuous casting and continuous pouring, it adopts staged control according to the tapping situation, the weight of molten steel in the tundish, and the dynamic change of the drawing speed, and determines the argon gas flow range corresponding to each pouring stage in the slab continuous casting and continuous pouring process based on a large number of experimental studies and application time verification.

[0043] The continuous casting and continuous pouring gas supply method of the present invention specifically includes the following steps:

[0044] S1. When starting to tap the ladle, when the molten steel flows into the tundish, turn on the argon gas source, supply argon gas into the annular gap gas channel 2 of the argon blowing stopper rod, and control the argon gas flow rate to be 5.5 NL / min to 6.5 NL / min. In a specific embodiment, the continuous supply time of argon gas is 5 to 10 minutes.

[0045] S2. During the pouring process, adjust the argon gas flow rate according to the weight of molten steel in the tundish and the current drawing speed, specifically as follows:

[0046] When the weight of molten steel in the tundish ≥ 30 t, then adjust the argon gas flow rate according to the current drawing speed; when the drawing speed > 1 m / min, adjust the argon gas flow rate to 4.5 to 6 NL / min; when the drawing speed ≤ 1 m / min, adjust the argon gas flow rate to 3 to 4.5 NL / min.

[0047] S3. At the end of a casting campaign, when the weight of molten steel in the tundish is less than 30 t (such as < 25 t, etc.), adjust the supplied argon gas flow rate until the pouring ends; in a specific embodiment, the argon gas flow rate is reduced to 3 to 5 NL / min.

[0048] By using the self-cleaning argon blowing stopper rod for improving nozzle nodulation and the continuous casting and continuous pouring gas supply method as described above, the continuous casting and continuous pouring process can be stabilized, the rod position curve of the argon blowing stopper rod during the pouring process is stable, and continuous pouring for more than 10 heats can be achieved; after pouring, there is no obvious nodulation on the rod head 3 of the stopper rod, the nozzle bowl and inner wall, the used argon blowing stopper rod is intact, and at the same time, the total oxygen content in the steel of the cast slab product is reduced to within 10 ppm.

[0049] The following further introduces the self-cleaning argon blowing stopper rod for improving nozzle nodulation and the continuous casting and continuous pouring gas supply method of the present invention with specific examples;

[0050] Example

[0051] Combined with Figure 1 As shown, this embodiment uses the self-cleaning argon blowing stopper rod for improving nozzle nodulation of the present invention. The stopper rod body 1 is made of aluminum-carbon material, the rod head 3 of the stopper rod is made of magnesia-carbon material, and the annular gap gas channel 2 is a steel annular pipeline. After drying and firing, an aluminum-carbon - magnesia-carbon composite integral stopper rod is produced.

[0052] Combined with Figure 1As shown, on the other end of the stopper body 1 away from the stopper head 3, there is a gas connection joint 4 extending outwards, which facilitates the quick installation and disassembly of the gas supply pipeline.

[0053] Combined with Figure 2 As shown, in the annular gap gas channel 2 provided in the stopper body 1, a rotating partition structure is provided in the annular gap between the outer wall 21 and the inner wall 22 of the channel; the upper end of the annular gap gas channel 2 is the gas inlet, which is connected to the gas connection joint 4; the lower end of the annular gap gas channel 2 has an annular gap opened at the stopper head 3, which is the annular gap outlet of the annular gap gas channel 2.

[0054] Combined with Figure 3 As shown, the upper part of each rib partition between the annular gaps is a straight section 231, and the lower part is a spiral section 232. The spiral section 232 is spiral with respect to the central vertical axis K of the stopper, and the end 233 of the spiral section 232 extends to the slit of the stopper head 3. The angle θ between the end 233 of the spiral section 232 and the vertical axis K is 60°.

[0055] Taking the pouring of a certain grade of calcium-treated aluminum-killed steel as an example, the tundish used in this embodiment: the baking temperature ≥ 1200 °C, the baking time is 90 - 180 min, the outer wall temperature of the nozzle ≥ 600 °C, and the continuous casting and continuous pouring gas supply method includes the following steps:

[0056] (1) When the ladle starts pouring and the molten steel flows into the tundish, turn on the argon gas source, supply argon gas into the annular gap gas channel 2 of the argon-blowing stopper, keep the supplied argon gas flow rate at 6 NL / min, and continuously introduce it for 8 min;

[0057] (2) When the weight of the molten steel in the tundish reaches 30 t, adjust the supplied argon gas flow rate to 5 NL / min according to the current casting speed of 1.2 m / min;

[0058] (3) At the end of the casting process of a casting campaign, when the weight of the molten steel in the tundish is less than 25 t, reduce the supplied argon gas flow rate to 4 NL / min until the casting is completed.

[0059] The continuous casting and continuous pouring gas supply method in this embodiment can make the continuous casting process stable, the stopper position curve stable during the casting process, and the increase value of the stopper position curve per hour does not exceed 2 mm, and more than 10 consecutive casts of this type of steel grade can be achieved. After the casting is completed, there is no obvious nodulation on the stopper head 3, the nozzle bowl and the inner wall, and the used stopper is intact; at the same time, the total oxygen content in the steel of the cast slab product is reduced to within 10 ppm.

[0060] Comparative example

[0061] In the existing argon-blowing stopper rod for continuous casting, the gas supply channel is a straight through-hole with a certain diameter opened along the axis of the stopper rod. A high-temperature resistant straight pipe is buried in the head of the stopper rod, and argon gas is introduced into the stopper rod through the high-temperature resistant straight pipe during casting, so that the argon gas is blown towards the nozzle. The flow rate of the argon gas blown during casting is basically constant, or occasionally adjusted manually according to the degree of situations such as argon back pressure and mold liquid level fluctuation.

[0062] The continuous casting stability of using the above-mentioned argon-blowing stopper rod and argon-blowing method is poor. There is a large fluctuation and tumbling phenomenon at the steel slag interface in the mold. The hourly increase value of the stopper rod position curve exceeds 8 mm. In some casting sequences, the argon-blowing back pressure rises sharply due to serious nozzle nodulation, and it is necessary to manually increase the argon-blowing amount to adapt. Moreover, the metallurgical quality of the product is not high, and the total oxygen content in the steel of the cast billet product is 15 - 20 ppm.

[0063] In summary, the self-cleaning argon-blowing stopper rod for improving nozzle nodulation involved in the present invention has a simple structure, low processing cost, and long service life. At the same time, it combines the argon gas flow rate strategies in different casting stages, ensures the stability of the casting state, gives full play to the role of the stopper rod blowing argon gas to improve nozzle nodulation and remove inclusions, effectively improves the inclusion nodulation state of the nozzle bowl and inner wall and the continuous casting state, and improves the quality of molten steel.

[0064] It should be noted that those of ordinary skill in the art in this technical field should recognize that the above embodiments are only used to illustrate the present invention, rather than to limit the present invention. As long as it is within the scope of the substantial spirit of the present invention, the changes and modifications to the above-mentioned embodiments will fall within the scope of the claims of the present invention.

Claims

1. A self-cleaning argon-blowing stopper for improving nozzle nodulation, characterized in that, It includes a stopper body, an annular gap gas channel, and a stopper head; The bottom of the stopper body is connected to the stopper head, and a gas connection joint connected to a gas supply pipeline is provided at one end of the stopper body away from the stopper head; The annular gap gas channel is arranged inside the stopper body; a gas inlet at one end of the annular gap gas channel is connected to the gas connection joint, and an annular gap outlet at the other end is arranged on the stopper head; a rotating strip rib partition structure is provided between the outer wall and the inner wall of the annular gap gas channel.

2. The self-cleaning argon-blowing stopper for improving nozzle nodulation according to claim 1, wherein, The rotating strip rib partition structure includes multiple spiral strip rib partitions, and each spiral strip rib partition includes a straight segment arranged in the upper part of the annular gap gas channel and a spiral segment arranged in the lower part of the annular gap gas channel; the spiral segment is connected to the straight segment.

3. The self-cleaning argon-blowing stopper for improving nozzle nodulation according to claim 2, wherein The spiral segment is spiral with respect to the central vertical axis of the stopper body, and the end of the spiral segment extends to the annular gap outlet of the annular gap gas channel.

4. The self-cleaning argon-blowing stopper for improving nozzle nodulation according to claim 3, characterized in that, The included angle θ between the end of the spiral segment and the vertical axis is 40 - 60°.

5. A continuous casting and continuous pouring gas supply method, characterized in that, Using the self-cleaning argon-blowing stopper for improving nozzle nodulation as described in any one of claims 1 - 4, it includes the following steps: S1. When the ladle starts pouring and the molten steel flows into the tundish, turn on the argon gas source, supply argon gas into the annular gap gas channel of the argon-blowing stopper, and control the argon gas flow rate to be 5.5 NL / min - 6.5 NL / min; S2. During the pouring process, adjust the argon gas flow rate according to the weight of the molten steel in the tundish and the current casting speed; S3. At the end of the casting campaign, when the weight of the molten steel in the tundish is less than 30 t, adjust the supplied argon gas flow rate until the pouring ends.

6. The continuous casting and continuous pouring gas supply method according to claim 5, characterized in that, In step S1, the continuous supply time of the argon gas is 5 - 10 min.

7. The continuous casting and continuous pouring gas supply method according to claim 5, characterized in that, In step S2: When the weight of the molten steel in the tundish ≥ 30 t, adjust the argon gas flow rate according to the current casting speed; When the casting speed > 1 m / min, adjust the argon gas flow rate to 4.5 - 6 NL / min; When the casting speed ≤ 1 m / min, adjust the argon gas flow rate to 3 - 4.5 NL / min.

8. The continuous casting and continuous pouring gas supply method according to claim 5, characterized in that, In step S3, the argon gas flow rate is 3 - 5 NL / min.

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