Expansion continuous casting tundish

Abstract

The utility model relates to the technical field of continuous casting, in particular to an expansion continuous casting tundish which comprises a tundish body, the tundish body comprises a shell, a heat insulation layer, a permanent layer and a working layer which are sequentially arranged from outside to inside, and the tundish body is provided with a straight inner mold and a steel receiving area located in the center of one side of the inner mold. The tundish body comprises an inner mold and an outer mold, four water gaps are formed in the bottom of the inner mold, the water gaps are used for pouring a casting blank with the section being 700-870 mm < 2 >, the capacity, used for containing molten steel, of the tundish body ranges from 60 tons to 62 tons, and the volume of the tundish body ranges from 8.5 m < 3 > to 8.7 m < 3 >. The tundish has the beneficial effects that the residence time of molten steel in the tundish is prolonged, inclusions have more sufficient time to float upwards, the residual quantity of the inclusions is reduced, and therefore the purity and the surface quality of steel billets are improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of continuous casting, and in particular to an expanded-capacity continuous-casting tundish. BACKGROUND

[0002] Steel is an important basic material for modern industry, and its quality directly affects the development of the national economy and the progress of society. As a core link of steel production, continuous casting technology significantly improves production efficiency and resource utilization efficiency by directly and continuously casting molten steel into billets, eliminating the intermediate link in the traditional process. The application of this technology not only improves the automation level of steel production, but also greatly reduces energy consumption, bringing huge economic and environmental benefits to steel enterprises. However, in actual application, continuous casting technology still faces many challenges, especially in the treatment of inclusions.

[0003] In the continuous casting process, the tundish, as the key equipment connecting the ladle and the mold, plays a crucial role. In order to ensure the purity of the molten steel and the quality of the final product, the existing tundish usually adopts retention and floating to reduce the number and volume of inclusions. Although the retention and floating measures improve the purity of the molten steel to some extent, there are still obvious deficiencies. For example, the 40-ton capacity tundish in the related art has a short molten steel residence time, resulting in a large number of fine inclusions remaining in the molten steel without sufficient floating, which seriously affects the mechanical properties and surface quality of the billet. CONTENT OF THE UTILITY MODEL

[0004] In order to reduce the content of inclusions in the molten steel flowing out of the water gap, the application provides an expanded-capacity continuous-casting tundish.

[0005] The expanded-capacity continuous-casting tundish provided by the application adopts the following technical scheme:

[0006] An expanded-capacity continuous-casting tundish, comprising a tundish body, the tundish body comprising an outer shell, an insulation layer, a permanent layer and a working layer arranged in sequence from outside to inside, the tundish body having a straight inner mold, and a receiving steel area located at the center of one side of the inner mold, the bottom of the inner mold being provided with four water gaps, the water gaps being used for pouring billets with a cross section of 700mm 2 ~870mm 2 , the capacity of the tundish body for containing molten steel being 60 tons~62 tons, and the volume of the tundish body being 8.5m 3 ~8.7m 3 .

[0007] By adopting the technical scheme, the tundish expanded to 60-62 tons not only increases the residence time of molten steel in the tundish, but also makes the temperature inside the tundish more uniform, with a temperature difference of not more than 7.0℃, thereby effectively reducing the generation and retention of inclusions and improving the purity of the molten steel and the quality of the final product. At the same time, the stable temperature condition also helps to maintain the stability of the pouring process, further improving the production efficiency and product qualification rate.

[0008] Optionally, the vertical thickness of the permanent layer is 140mm, and the bottom thickness of the permanent layer is 160mm.

[0009] By adopting the technical scheme, the vertical thickness of the permanent layer is reduced to 140mm, and the bottom thickness is reduced to 160mm, which significantly reduces the material usage and reduces the overall weight of the tundish, thereby improving the installation and maintenance convenience of the tundish. At the same time, by optimizing the thickness of the permanent layer, the tundish increases the internal space under the premise of ensuring the heat insulation performance, thereby increasing the molten steel capacity and prolonging the floating time of inclusions in the tundish, improving the removal efficiency of inclusions, and further improving the purity of the molten steel and the quality of the final product.

[0010] Optionally, the vertical thickness of the working layer is 90mm, and the bottom thickness of the working layer is 75mm.

[0011] By adopting the technical scheme, the vertical thickness of the working layer is reduced to 90mm, and the bottom thickness is reduced to 75mm, which increases the overall capacity of the tundish. This not only increases the residence time of molten steel in the tundish, which is conducive to the more complete floating and removal of inclusions, thereby improving the purity of the molten steel and the quality, but also keeps the heat loss within the allowable range, maintaining the stability of the molten steel temperature in the tundish. In addition, reducing the thickness of the working layer also helps to reduce the weight of the tundish itself, facilitating transportation and installation.

[0012] Optionally, the receiving area is provided with an integrated flow stabilizer.

[0013] By adopting the technical scheme, the integrated flow stabilizer can significantly improve the flow state of molten steel in the receiving area, reduce vortex and turbulence, and make the molten steel flow more smoothly into the tundish. This not only helps to improve the purity of the molten steel, but also effectively reduces the generation and retention of inclusions, thereby improving the quality and performance of the final casting blank.

[0014] Optionally, the capacity of the receiving area is 5-6 tons, the volume of the receiving area is 0.7-0.8m3, the capacity of the inner mold is 55-56 tons, and the volume of the inner mold is 7.8-7.9m3.

[0015] By adopting the technical scheme, the specific capacity and volume design of the receiving area and the inner mold are increased, the molten steel in the tundish is more evenly distributed, the residence time of the molten steel in the tundish is increased, and the floating efficiency of inclusions is improved. Specifically, the capacity of the receiving area is set to 5-6 tons, and the volume is 0.7m 3 ~0.8m 3 , which ensures the stability of the molten steel entering the tundish, reduces the vortex and turbulent flow phenomenon, and is beneficial to the preliminary separation of inclusions. The capacity of the inner mold is set to 55-56 tons, and the volume is 7.8m 3 ~7.9m 3 , which further prolongs the residence time of the molten steel in the tundish, so that more fine inclusions have enough time to float and be removed, and the purity and surface quality of the billet are significantly improved.

[0016] Optionally, the receiving area away from the inner mold is provided with a slag discharge groove.

[0017] By adopting the technical scheme, the slag discharge groove is added to effectively collect and discharge inclusions in the molten steel away from the inner mold of the receiving area, further improving the purity of the molten steel. This not only reduces the influence of inclusions on the quality of the cast billet, but also improves the mechanical properties and surface quality of the final product, so that the product meets the national standard requirements. In addition, the design of the slag discharge groove also helps to keep the internal environment of the tundish clean, prolong the service life of the tundish, and reduce the maintenance cost.

[0018] In summary, the present application includes at least one of the following beneficial technical effects:

[0019] 1. By increasing the tundish capacity from 40 tons to 60-62 tons, the residence time of the molten steel in the tundish is significantly increased, so that the inclusions have more time to float, the residual amount of inclusions is reduced, and the purity and surface quality of the billet are improved;

[0020] 2. The thickness of the permanent layer and the working layer is reduced, which not only reduces the overall weight of the tundish, but also increases the volume of the tundish, which is beneficial to further improve the flowability and uniformity of the molten steel, and enhances the metallurgical effect of the tundish;

[0021] 3. The overall flow stabilizer and the slag discharge groove provided in the receiving area effectively control the speed and direction of the molten steel flowing into the tundish, reduce the turbulent flow phenomenon, avoid the generation of secondary oxides, and ensure the stability and purity of the molten steel. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a structural schematic diagram of the expanded continuous casting tundish provided by the embodiment of the present application.

[0023] Figure 2Fig. 1 is a schematic diagram of an internal structure of a capacity-expanded continuous casting tundish provided by an embodiment of the present application.

[0024] Reference signs: 1-tundish body; 101-outer shell; 102-thermal insulation layer; 103-permanent layer; 104-working layer; 2-inner mold; 3-steel receiving area; 301-slagging groove; 4-integral flow stabilizer; 5-nozzle. DETAILED DESCRIPTION

[0025] The following will be described in detail in combination with the accompanying drawings. Figures 1-2 The present application will be further described in detail.

[0026] In the related art, a tundish with a capacity of 40 tons is used when producing a casting blank with a section of 700-870 mm 2 The residence time of molten steel in the tundish under different casting specifications and average casting speeds is shown in Table 1.

[0027]

[0028] Table 1 Residence time of molten steel in a 40-ton tundish

[0029] According to the Stokes formula, the floating speed of inclusions with different diameters in the process of using the tundish can be approximately calculated, and the specific cases are shown in Table 2.

[0030]

[0031] Table 2 Time required for floating of inclusions with different diameters in the tundish

[0032] According to the data in Table 2, when the tundish with a capacity of 40 tons in the related art is used to cast a casting blank with a section of 700-870 mm 2 , the time of inclusions with a diameter of 70 μm in the floating process is 8.44 minutes. This indicates that for inclusions with a diameter less than or equal to 70 μm, their floating time exceeds the average residence time of molten steel in the tundish. Therefore, these inclusions do not have enough time to fully float under the current tundish capacity.

[0033] Considering the market demand for product quality, it is necessary to expand the capacity of the tundish to prolong the residence time of molten steel in the tundish. This not only helps to improve product quality, but also reduces the subsequent deslagging step in the production process, thereby improving production efficiency.

[0034] An embodiment of the present application discloses a capacity-expanded continuous casting tundish.

[0035] As Figure 1As shown, the expanded capacity continuous casting tundish includes a tundish body 1, which comprises, from outside to inside, an outer shell 101, an insulation layer 102, a permanent layer 103 and a working layer 104. The tundish body 1 has a straight inner mold 2, and a receiving steel area 3 at the center of one side of the inner mold 2. The bottom of the inner mold 2 is provided with four water gaps 5 for pouring a casting blank with a cross section of 700mm 2 ~870mm 2 . The tundish body 1 has a capacity of 60 tons to 62 tons for containing molten steel, and a volume of 8.5m 3 ~8.7m 3 . The tundish expanded to 60 tons to 62 tons not only increases the residence time of molten steel in the tundish, but also makes the internal temperature of the tundish more uniform, with a temperature difference of not more than 7.0℃, thereby effectively reducing the generation and retention of inclusions, improving the purity of the molten steel and the quality of the final product. At the same time, the stable temperature condition also helps to maintain the stability of the pouring process, further improving the production efficiency and product qualification rate.

[0036] As Figure 1 shown, the vertical thickness of the permanent layer 103 is set to 140mm, and the bottom thickness is 160mm. The vertical thickness of the working layer 104 is 90mm, and the bottom thickness is 75mm. By reducing the vertical thickness of the permanent layer 103 to 140mm and the bottom thickness to 160mm, the use of materials is significantly reduced, and the overall weight of the tundish is reduced, which is beneficial to the convenience of installation and maintenance of the tundish. At the same time, by optimizing the thickness of the permanent layer 103, the heat insulation performance is ensured, the internal space of the tundish is increased, the molten steel capacity is improved, the floating time of inclusions in the tundish is prolonged, the removal efficiency of inclusions is improved, and the purity of the molten steel and the quality of the final product are improved.

[0037] Similarly, the vertical thickness of the working layer 104 is reduced to 90mm, and the bottom thickness is reduced to 75mm, so that the overall capacity of the tundish is increased. This not only prolongs the residence time of molten steel in the tundish, which is beneficial to the more sufficient floating and removal of inclusions, thereby improving the purity of the molten steel and the quality, but also ensures that the heat loss remains within the allowable range, maintaining the stability of the molten steel temperature in the tundish. In addition, reducing the thickness of the working layer 104 also helps to reduce the weight of the tundish itself, facilitating transportation and installation.

[0038] As Figure 1As shown, an integrated flow stabilizer 4 can be installed in the steel receiving zone 3. The integrated flow stabilizer 4 can significantly improve the flow state of molten steel in the steel receiving zone 3, reduce eddies and turbulence, and allow the molten steel to flow more smoothly into the tundish. This not only helps to improve the purity of the molten steel, but also effectively reduces the formation and retention of inclusions, thereby improving the quality and performance of the final cast billet.

[0039] Specifically, the steel receiving zone 3 of the tundish has a design capacity between 5 and 6 tons, with a volume ranging from 0.7 to 0.8 cubic meters; the inner mold 2 has a design capacity of 55 to 56 tons, with a volume of 7.8 to 7.9 cubic meters. By optimizing the capacity and volume parameters of the steel receiving zone 3 and the inner mold 2, a balanced distribution of molten steel within the tundish is achieved, thereby increasing the residence time of molten steel in the tundish and improving the efficiency of inclusion flotation. Specifically, setting the capacity of the steel receiving zone 3 to 5 to 6 tons and the volume to 0.7 to 0.8 cubic meters ensures the stability of the molten steel entering the tundish, reduces the occurrence of eddies and turbulence, and facilitates the initial separation of inclusions. The capacity of the inner mold 2 is set to 55 to 56 tons, and the volume is 7.8 to 7.9 cubic meters, which further extends the residence time of molten steel in the tundish, allowing more small inclusions to float to the surface and be removed, significantly improving the purity and surface quality of the billet.

[0040] In this embodiment, the specific capacity and volume of the steel receiving area 3 and the inner mold 2 are shown in Table 3.

[0041]

[0042] Table 3 Specific Capacities

[0043] like Figure 1 As shown, a slag discharge trough 301 is provided on the side of the receiving zone 3 away from the inner mold 2. The addition of the slag discharge trough 301 allows for the effective collection and discharge of inclusions in the molten steel on the side of the receiving zone 3 away from the inner mold 2, further improving the purity of the molten steel. This not only reduces the impact of inclusions on the quality of the cast billet but also improves the mechanical properties and surface quality of the final product, making the product more compliant with national standards. Furthermore, the design of the slag discharge trough 301 also helps maintain the cleanliness of the internal environment of the tundish, extending the service life of the tundish and reducing maintenance costs. The performance indicators for an expanded continuous casting tundish according to an embodiment of this application are as follows:

[0044] 1. The molten steel capacity reaches approximately 60 to 62 tons;

[0045] 2. The residence time of molten steel in the tundish is ≥650s.

[0046] 3. During the continuous casting process with full liquid level pouring, the proportion of inclusions detected in random sampling is ≤7.0%;

[0047] 4. The temperature difference of the tundish is less than or equal to 7.0℃.

[0048] The above are preferred embodiments of the present application, and are not intended to limit the protection scope of the present application, and thus: any equivalent changes made according to the structure, shape, principle of the present application should be encompassed within the protection scope of the present application.

Claims

1. A continuous casting tundish with expanded capacity, comprising a tundish body (1), wherein the tundish body (1) comprises, from the outside to the inside, an outer shell (101), an insulation layer (102), a permanent layer (103), and a working layer (104), characterized in that: The tundish body (1) has a straight inner mold (2) and a steel-receiving area (3) located at the center of one side of the inner mold (2). The bottom of the inner mold (2) is provided with four sprue gates (5), which are used for casting sections with a cross-section of 700mm. 2 ~870mm 2 The tundish body (1) is used to hold 60 to 62 tons of molten steel, and its volume is 8.5 m³. 3 ~8.7m 3 .

2. The expanded continuous casting tundish according to claim 1, characterized in that, The thickness of the vertical surface of the permanent layer (103) is 140 mm, and the thickness of the bottom surface of the permanent layer (103) is 160 mm.

3. The expanded continuous casting tundish according to claim 1, characterized in that, The working layer (104) has a vertical thickness of 90 mm and a bottom thickness of 75 mm.

4. The expanded continuous casting tundish according to claim 1, characterized in that, The steel receiving area (3) is equipped with an integrated current stabilizer (4).

5. The expanded continuous casting tundish according to claim 4, characterized in that, The steel receiving area (3) has a capacity of 5 to 6 tons and a volume of 0.7 m³. 3 ~0.8m 3 The inner mold (2) has a capacity of 55 to 56 tons and a volume of 7.8 m³. 3 ~7.9m 3 .

6. The expanded continuous casting tundish according to claim 4, characterized in that, The steel receiving area (3) is provided with a slag discharge trough (301) on the side away from the inner mold (2).

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