Compensation type casting method for special-shaped blank

Abstract

The invention discloses a beam blank compensation type casting method, which relates to the technical field of beam blank continuous casting machine production, and comprises the following steps of: communicating a tundish with a beam blank crystallizer through a first injection flow channel and a second injection flow channel; the opening degree between the stopper and the second injection port is adjusted through the stopper guide mechanism to control the molten steel flow of the second injection channel so as to ensure enough starting time; the first flow injection port injects molten steel into the special-shaped blank crystallizer through the first main flow channel, and meanwhile, the second flow injection port injects molten steel into the special-shaped blank crystallizer through the first main flow channel; the molten steel flow, the molten steel liquid level height in the crystallizer and the casting blank quality are continuously monitored; when production fluctuation occurs and the flow of the second flow injection channel needs to be adjusted, the opening degree between the stopper rod and the second flow injection opening is adjusted through the stopper rod guide mechanism to control the amount of molten steel flowing into the special-shaped blank crystallizer, the structure is simple, use is convenient, and the casting quality of special-shaped blanks is effectively guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of special-shaped bloom continuous casting machine production, and particularly to a compensation casting method for special-shaped blooms. Background Art

[0002] The cross-sectional shape of a special-shaped bloom is complex. Compared with ordinary bloom types, the web is narrow, the width and flange thickness are large, the cooling is uneven, and the production is difficult. Therefore, the choice of molten steel casting mode has a great influence on production stability and quality control. Molten steel for special-shaped bloom production is poured from the tundish nozzle into the mold. There are two ways to control the pouring flow in this process: the casting method of the single-nozzle stopper automatic flow control mode and the casting method of the double-sized nozzle casting speed control mode.

[0003] (1) Casting method of the single-nozzle stopper automatic flow control mode

[0004] The single-nozzle casting position of each strand of the special-shaped bloom is at the center of the flange triangular area on the north side of the mold. The guiding mechanism is used to adjust the position of the stopper head of the tundish and the upper nozzle to control the molten steel flow rate. By replacing the sized nozzle, the service life of the tundish can be appropriately extended.

[0005] The casting method of the single-nozzle stopper automatic flow control mode is beneficial to stabilizing the molten steel level in the mold; the casting speed can be kept constant for a long time. The molten steel flowing into the mold is adjusted by the stopper, and the billet shell is formed stably and uniformly, and the controllability of the production process is relatively strong. However, the flow control life is short, generally casting for 16 - 24 hours, the production cost increases, and it is not suitable for the low-cost manufacturing production of plain carbon steel; moreover, casting the special-shaped bloom with a single nozzle belongs to asymmetric casting, the molten steel flow field in the mold is uneven, the flow velocity on one side increases, the melting speeds of the mold powder on the north and south sides are different, and it is easy to have uneven lubrication, so sticking breakout and billet surface quality problems occur.

[0006] Casting method of the double-sized nozzle casting speed control mode

[0007] The double-nozzle casting position of each strand of the special-shaped bloom is at the center of the flange triangular areas on the north and south sides of the mold. The molten steel flow rate flowing into the mold is adjusted by the inner diameter size of the sized nozzle. A sized nozzle is used on the south side of each pouring stream, and a or sized nozzle is used on the north side. During production, the casting speed is adjusted by replacing the size of the sized nozzle.

[0008] The casting method with the double-sizing nozzle and casting speed control flow pattern has good symmetry and uniformity in the flow field distribution in the mold, which is beneficial to the uniform and stable growth of the billet shell, the melting of the mold powder and the floating and removal of inclusions. Moreover, by replacing the sizing nozzle, the tundish life is extended and the number of continuous casting heats is increased. However, during the starting casting, the tundish pouring stream is prone to deflect, causing the iron filings to be washed over and steel to adhere to the mold; there are two methods to adjust the casting speed in response to production fluctuations: one is to replace the sizing nozzle and the submerged nozzle, and frequent replacement is likely to cause steel clamping accidents in the slide mechanism, increase the refractory consumption and the amount of cast billet cut-offs, increase the labor intensity of workers and the production cost; the other is to control the molten steel level in the tundish. When the level is low, the residence time of the molten steel in the tundish is short, the inclusions do not float up sufficiently, affecting the quality of the cast billet; the erosion of the tundish bottom refractories by the steel flow is strengthened, reducing the service life of the flow stabilizer; at the same time, there is not enough buffering time during the ladle transfer process, and production accidents such as slag flowing into the mold and even the tundish being emptied and the casting stopped are likely to occur.

[0009] Based on the above casting method, when encountering situations such as time sequence fluctuations, equipment failures, nozzle clogging, mold liquid level fluctuations, waiting for molten iron and high-temperature molten steel during the production of special-shaped billets, in the existing flow control modes, it is found that the stopper flow control has a short service life, restricting the improvement of the number of continuous casting heats; the sizing nozzle flow control is prone to deflect during the starting casting; in response to production fluctuations, the accident rate is high, the refractory consumption is large, the amount of cast billet cut-offs is large and it is not conducive to the quality control of the cast billet during the process of adjusting the casting speed. Summary of the Invention

[0010] The purpose of the present invention is to provide a compensation casting method for special-shaped billets to solve the problems existing in the above-mentioned prior art, with a simple structure, convenient use and effectively ensuring the casting quality of special-shaped billets.

[0011] To achieve the above purpose, the present invention provides the following solution:

[0012] The present invention provides a compensation casting method for special-shaped billets, including the following steps: inserting the first pouring port at the bottom of the tundish into the first submerged nozzle at the center of the triangular area of the south flange in the special-shaped billet mold to form a closed first pouring channel, inserting the second pouring port at the bottom of the tundish into the second submerged nozzle at the center of the triangular area of the north flange in the special-shaped billet mold to form a closed second pouring channel, and adjusting the opening degree between the stopper and the second pouring port through the stopper guiding mechanism to control the molten steel flow rate in the second pouring channel to ensure sufficient starting time; the first pouring port injects molten steel into the special-shaped billet mold through the first main channel, and at the same time the second pouring port injects molten steel into the special-shaped billet mold through the first main channel; continuously monitor the molten steel flow rate, the height of the molten steel level in the mold and the quality of the cast billet; when production fluctuations occur and it is necessary to adjust the flow rate of the second pouring channel, adjust the opening degree between the stopper and the second pouring port through the stopper guiding mechanism to control the amount of molten steel flowing into the special-shaped billet mold.

[0013] Preferably, a first water inlet is provided at the top of the first pouring nozzle, and a second water inlet is provided at the top of the second pouring nozzle. The stopper rod is configured to be disposed above the second water inlet and can adjust the distance between the stopper rod and the second water inlet through the stopper rod guiding mechanism to control the flow rate of the second pouring channel.

[0014] Preferably, the first pouring nozzle is a constant diameter nozzle, and the second pouring nozzle is a constant diameter nozzle.

[0015] Preferably, the stopper rod guiding mechanism includes a cross arm and a lifting device. One end of the cross arm is detachably and fixedly connected to the top end of the stopper rod, and the other end extends out of the tundish and is detachably and fixedly connected to the output end of the lifting device. The lifting direction of the lifting device is the vertical direction.

[0016] Preferably, the lifting device includes a guide rail, a lifting rod, a sector gear, and a handle. The guide rail is detachably and fixedly connected to the outer side wall of the tundish. The lifting rod is slidably connected to the guide rail. A rack is provided at the bottom of the lifting rod. The sector gear is meshed with the rack. The handle is fixedly connected to the center of the sector gear, and the handle is hinged to the guide rail at the connection with the sector gear.

[0017] Preferably, a locking member is further included, and the locking member can keep the lifting rod in the lifted or lowered position.

[0018] Preferably, the locking member is a locking bolt. A threaded hole is provided on one side of the guide rail. The locking bolt is threadedly connected to the threaded hole, and one end of the locking bolt can extend into the guide rail and press the lifting rod against the other side of the guide rail.

[0019] The present invention has achieved the following technical effects compared with the prior art:

[0020] The object of the present invention is to provide a compensation casting method for special-shaped billets. By providing different pouring channels on the north and south sides of the special-shaped billet mold, simultaneous pouring on both sides is realized, and the casting efficiency is improved. The stopper rod guiding mechanism is used to adjust the molten steel flow rate of the north-side pouring channel, ensuring sufficient starting time, making the starting process more stable, reducing production accidents caused by unstable starting, and being able to better adapt to the casting requirements of special-shaped billets by adjusting the molten steel flow rate of the second pouring channel, improving the quality of the cast billet and production stability. Description of the Drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Figure 1 It is a structural sectional view of the tundish in the special-shaped billet compensation casting method provided by the present invention;

[0023] Figure 2 It is a top view of the special-shaped billet mold in the special-shaped billet compensation casting method provided by the present invention;

[0024] Figure 3 It is a structural schematic diagram when the lifting device and the stopper rod are used in combination in the special-shaped billet compensation casting method provided by the present invention;

[0025] Figure 4 It is a sectional view of the lifting device in the special-shaped billet compensation casting method provided by the present invention;

[0026] In the figure: 1. Special-shaped billet mold; 2. First submerged nozzle; 3. Second submerged nozzle; 4. Tundish; 5. First pouring port; 6. Second pouring port; 7. Cross arm; 8. Stopper rod; 9. Guide rail; 10. Lifting rod; 11. Sector gear; 12. Handle; 13. Locking bolt; 14. Molten steel; 15. Second upper nozzle. Specific embodiments

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0028] The purpose of the present invention is to provide a special-shaped billet compensation casting method to solve the problems existing in the above-mentioned prior art. It has a simple structure, is easy to use, and effectively guarantees the casting quality of the special-shaped billet.

[0029] To make the above-mentioned objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0030] The present invention provides a special-shaped billet compensation casting method, as Figures 1 to 4As shown in the figure, the method includes the following steps: Insert the first pouring nozzle 5 at the bottom of the tundish 4 into the first submerged nozzle 2 at the center of the triangular area of the south flange in the special-shaped billet mold 1 to form a sealed first pouring channel; insert the second pouring nozzle 6 at the bottom of the tundish 4 into the second submerged nozzle 3 at the center of the triangular area of the north flange in the special-shaped billet mold 1 to form a sealed second pouring channel; adjust the opening degree between the stopper rod 8 and the second pouring nozzle 6 through the guiding mechanism of the stopper rod 8 to control the molten steel 14 flow rate in the second pouring channel to ensure sufficient starting time; the first pouring nozzle 5 injects molten steel 14 into the special-shaped billet mold 1 through the first main channel, and at the same time, the second pouring nozzle 6 injects molten steel 14 into the special-shaped billet mold 1 through the first main channel; continuously monitor the molten steel 14 flow rate, the molten steel 14 liquid level height in the mold and the quality of the cast billet; when production fluctuations occur and it is necessary to adjust the flow rate of the second pouring channel, adjust the opening degree between the stopper rod 8 and the second pouring nozzle 6 through the guiding mechanism of the stopper rod 8 to control the amount of molten steel 14 flowing into the special-shaped billet mold 1. By setting different pouring channels on the north and south sides of the special-shaped billet mold 1, simultaneous double-side casting is realized, improving the casting efficiency. Using the guiding mechanism of the stopper rod 8 to adjust the molten steel 14 flow rate in the north-side pouring channel ensures sufficient starting time, makes the starting process more stable, and reduces production accidents caused by unstable starting.

[0031] In a preferred solution of this embodiment, a first upper nozzle is provided at the top of the first pouring nozzle 5, and a second upper nozzle 15 is provided at the top of the second pouring nozzle 6. The stopper rod 8 is used to be arranged above the second upper nozzle 15, and the distance between the stopper rod 8 and the second upper nozzle 15 can be adjusted through the guiding mechanism of the stopper rod 8 to control the flow rate of the second pouring channel. Setting the upper nozzle facilitates the connection with the tundish 4, enabling the molten steel 14 to flow smoothly into the pouring channel. By adjusting the distance between the stopper rod 8 and the second upper nozzle 15 to control the molten steel 14 flow rate, the operation is more precise, and the flow rate can be flexibly adjusted according to actual production requirements.

[0032] In a preferred solution of this embodiment, the first pouring nozzle 5 is a constant-diameter nozzle, and the second pouring nozzle 6 is a constant-diameter nozzle. By using constant-diameter nozzles of different sizes, the constant-diameter nozzle is used on the south side, and the constant-diameter nozzle on the north side cooperates with the guiding mechanism of the stopper rod 8, which can better meet the casting requirements of the special-shaped billet, improving the quality of the cast billet and production stability.

[0033] In a preferred solution of this embodiment, the stopper rod 8 guiding mechanism includes a cross arm 7 and a lifting device. One end of the cross arm 7 is detachably and fixedly connected to the top end of the stopper rod 8, and the other end extends out of the tundish 4 and is detachably and fixedly connected to the output end of the lifting device. The lifting direction of the lifting device is the vertical direction. This design of the stopper rod 8 guiding mechanism makes the lifting operation of the stopper rod 8 more stable and reliable, and can accurately control the molten steel 14 flow rate. The detachable connections of the cross arm 7 with the stopper rod 8 and the lifting device facilitate the installation and maintenance of the equipment.

[0034] In a preferred solution of this embodiment, the lifting device includes a guide rail 9, a lifting rod 10, a sector gear 11 and a handle 12. The guide rail 9 is detachably and fixedly connected to the outer side wall of the tundish 4. The lifting rod 10 is slidably connected to the guide rail 9. A rack is provided at the bottom of the lifting rod 10. The sector gear 11 is meshed with the rack. The handle 12 is fixedly connected to the center of the sector gear 11, and the handle 12 is hinged to the guide rail 9 at the connection with the sector gear 11. The lifting device has a simple structure and is convenient to operate. By rotating the sector gear 11 with the handle 12, the lifting rod 10 is driven to slide in the guide rail 9, so as to realize the lifting of the stopper rod 8, and can quickly respond to production fluctuations and adjust the molten steel 14 flow rate.

[0035] In a preferred solution of this embodiment, a locking member is further included. The locking member can keep the lifting rod 10 in the position after lifting. The setting of the locking member can ensure that the lifting rod 10 remains stable after being adjusted to the appropriate position, avoid the fluctuation of the molten steel 14 flow rate caused by accidental shaking, and improve the stability and reliability of production.

[0036] In a preferred solution of this embodiment, the locking member is a locking bolt 13. A threaded hole is provided on one side of the guide rail 9. The locking bolt 13 is threadedly connected to the threaded hole and one end of the locking bolt 13 can extend into the guide rail 9 and press the lifting rod 10 against the other side of the guide rail 9. Using the locking bolt 13 as the locking member has a simple structure, low cost and convenient operation. It can effectively fix the lifting rod 10 on the guide rail 9, ensure the stable position of the stopper rod 8, and thus ensure the stable control of the molten steel 14 flow rate.

[0037] In the present invention, specific examples are used to elaborate the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A compensatory casting method for profiled blanks, characterized in that: The following steps are involved: Insert the first injection port at the bottom of the tundish into the first submerged nozzle at the center of the triangular area of ​​the south flange of the profiled blank crystallizer to form a closed first injection channel, insert the second injection port at the bottom of the tundish into the second submerged nozzle at the center of the triangular area of ​​the north flange of the profiled blank crystallizer to form a closed second injection channel, and adjust the opening degree between the stopper rod and the second injection port through the stopper rod guide mechanism to control the molten steel flow rate of the second injection channel to ensure sufficient starting time; The first injection port injects molten steel into the profiled blank crystallizer through the first main flow channel, and the second injection port injects molten steel into the profiled blank crystallizer through the first main flow channel; Continuously monitor the molten steel flow rate, the molten steel level in the crystallizer and the quality of the ingot; When production fluctuations occur and the flow rate of the second injection channel needs to be adjusted, the amount of molten steel flowing into the profiled blank crystallizer is controlled by adjusting the opening degree between the stopper rod and the second injection port through the stopper rod guide mechanism.

2. The compensatory casting method of profiled blank according to claim 1, characterized in that: A first water inlet is arranged at the top of the first injection port, a second water inlet is arranged at the top of the second injection port, the stopper rod is used to be arranged above the second water inlet, and the distance between the stopper rod and the second water inlet can be adjusted by the stopper rod guide mechanism to control the flow of the second injection channel.

3. The compensatory casting method of profiled blank according to claim 2, characterized in that: The first injection port is Sizing nozzle, the second injection nozzle is Fixed diameter nozzle.

4. The compensatory casting method of profiled blank according to claim 3, characterized in that: The stopper rod guiding mechanism comprises a cross arm and a lifting device, one end of the cross arm is detachably fixedly connected to the top end of the stopper rod, and the other end extends out of the tundish and is detachably fixedly connected to the output end of the lifting device, and the lifting direction of the lifting device is vertical.

5. The compensatory casting method of profiled blank according to claim 4, characterized in that: The lifting device includes a guide rail, a lifting rod, a sector gear and a handle. The guide rail is detachably fixedly connected to the outer side wall of the tundish, the lifting rod is slidably connected to the guide rail, the bottom of the lifting rod is arranged on a rack, the sector gear is meshingly connected to the rack, the handle is fixedly connected to the center of the sector gear, and the handle is hingedly connected to the guide rail at the connection with the sector gear.

6. The compensatory casting method of profiled blank according to claim 5, characterized in that: It also includes a locking member, which can keep the lifting rod in a raised position.

7. The compensatory casting method of profiled blank according to claim 6, characterized in that: The locking member is a locking bolt, one side of the guide rail is provided with a threaded hole, the locking bolt is threadedly connected to the threaded hole and one end of the locking bolt can extend into the guide rail and tighten the lifting rod to the other side of the guide rail.

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