Continuous casting device and continuous casting method

Abstract

The invention relates to a continuous casting device and a continuous casting method. A continuous casting device comprises a tundish and a crystallizer and further comprises a separating wall used for separating the tundish into a first cavity and a second cavity, the first cavity is used for bearing base body molten steel, and the second cavity is used for bearing blank shell molten steel. A communicating gap is formed between the edge of the liquid separation layer and the inner wall of the crystallizer; a blank shell casting space is arranged above the liquid isolation layer in the crystallizer, and a matrix casting space is arranged below the liquid isolation layer in the crystallizer; the blank shell casting space communicates with the base body casting space through the communicating gap. The molten steel conveying module comprises a first runner and a second runner; the first runner is used for inputting matrix molten steel into the matrix casting space from the first cavity; and the second runner is used for inputting the blank shell molten steel into the blank shell casting space from the second cavity. And two kinds of molten steel are cast at the same time and are combined, so that the quality of a produced casting blank is more stable.

Description

Technical Field

[0001] The present application relates to the technical field of steelmaking continuous casting, and in particular to a continuous casting device and a continuous casting method. Background Art

[0002] With the development of steelmaking and continuous casting technology, steel composite technology has emerged, which can ensure that the produced materials have multiple performance guarantees.

[0003] In the related technologies, the double-sided composite plate materials are mostly formed by hot rolling composite method or explosive composite method, both of which are to composite solid materials with solid materials. Although they are pressed together by external force, there are still problems such as loose bonding, unstable quality and performance, and high costs. Furthermore, there are some technologies that realize solid-liquid bonding, but when one of the outer metal liquid and the inner metal liquid condenses into a solid first, defects often occur in the bonding position of the composite. Especially in the production process of some billet shells, the size and lateral span of the generated billet shells are large, and it is not easy to observe the state of the matrix steel liquid before forming the matrix. Combined with the above problems, it is more difficult to process. Summary of the invention

[0004] Based on this, it is necessary to provide a continuous casting device and a continuous casting method to address the problem of poor production quality of composite slabs in the field of composite continuous casting.

[0005] A continuous casting device, comprising a tundish and a crystallizer, further comprising:

[0006] A partition wall is used to separate the tundish into a first cavity and a second cavity, the first cavity is used to carry the matrix steel liquid, and the second cavity is used to carry the shell steel liquid;

[0007] The liquid barrier layer is placed inside the crystallizer, and a connecting gap is opened between the edge of the liquid barrier layer and the inner wall of the crystallizer; a blank shell casting space is provided above the liquid barrier layer in the crystallizer, and a matrix casting space is provided below the liquid barrier layer in the crystallizer; the blank shell casting space is connected with the matrix casting space through the connecting gap;

[0008] The molten steel conveying module comprises a first flow channel and a second flow channel; one end of the first flow channel is connected to the first cavity, and the other end passes through the liquid barrier layer and is connected to the matrix casting space, so as to transfer the matrix molten steel from the first cavity to the matrix casting space;

[0009] One end of the second flow channel is connected to the second cavity, and the other end is connected to the billet shell casting space, and is used for inputting the billet shell molten steel from the second cavity into the billet shell casting space.

[0010] In one embodiment, the liquid barrier layer includes a substrate positioned inside the crystallizer, and a connecting gap is opened between the side edge of the substrate and the inner wall of the crystallizer; a bearing groove is arranged on the top surface of the substrate, and the blank shell casting space is opened in the bearing groove.

[0011] In one of the embodiments, the liquid isolation layer also includes an additional plate arranged above the substrate, and the substrate is provided with a protrusion between its edge and the edge of the bearing groove; the additional plate covers the protrusion; a connecting hole is opened between the protrusion and the additional plate; the two ends of the connecting hole are respectively connected to the blank shell casting space and the connecting gap.

[0012] In one of the embodiments, it also includes: a through pipe that passes through the top of the liquid barrier layer into the matrix casting space; the through pipe connects the matrix casting space to the outside of the crystallizer; a floating measuring rod is arranged in the through pipe, and the end of the floating measuring rod can extend along the through pipe to the outside of the crystallizer, and a scale line is arranged at the end of the floating measuring rod.

[0013] In one embodiment, a first flow opening is formed on the bottom surface of the first cavity, and a first throttling member for controlling the opening and closing of the first flow opening is disposed in the first cavity;

[0014] A second flow opening is formed on the bottom surface of the second cavity, and a second throttling member for controlling the opening and closing of the second flow opening is disposed in the first cavity.

[0015] In one of the embodiments, it further includes: a gas delivery mechanism, which connects the first flow channel and the second flow channel and is used to introduce inert protective casting gas into the first flow channel and the second flow channel.

[0016] In one of the embodiments, the molten steel conveying module is configured as an integrally formed conveying pipe body, and the first flow channel and the second flow channel are independently opened inside the conveying pipe body; the first flow channel is provided with a first connecting port connected to the substrate casting space, and the second flow channel is provided with a second connecting port connected to the shell casting space, and the first connecting port and the second connecting port are staggered.

[0017] A continuous casting method, applicable to the above-mentioned continuous casting device, comprises:

[0018] Injecting matrix steel liquid into the first cavity and injecting shell steel liquid into the second cavity;

[0019] Opening the first flow channel to allow the matrix molten steel to flow into the matrix casting space;

[0020] Observe the liquid level of the matrix steel liquid in the matrix casting space, and when the liquid level of the matrix steel liquid reaches a preset liquid level, open the second flow channel to allow the shell steel liquid to flow into the shell casting space;

[0021] Adding protective slag above the molten steel shell;

[0022] The first flow channel and the second flow channel are continuously opened until the matrix steel liquid in the first cavity and the shell steel liquid in the second cavity are completely out of the cavity. During this process, the shell steel liquid will flow into the matrix casting space through the connecting gap, so that the shell steel liquid and the matrix steel liquid are combined and solidified from the outside to the inside.

[0023] In one embodiment, opening the first flow channel to allow the matrix molten steel to flow into the matrix casting space includes: introducing an inert protective casting gas into the matrix molten steel while the matrix molten steel flows.

[0024] In one embodiment, the liquid level of the matrix steel liquid in the matrix casting space is observed, a preset liquid level is set in the crystallizer, and when the liquid level of the matrix steel liquid reaches the preset liquid level, the second flow channel is opened to allow the shell steel liquid to flow into the shell casting space, including:

[0025] A float observation device is arranged in the matrix casting space, and the liquid level of the matrix molten steel is observed through the float observation device.

[0026] The above-mentioned continuous casting device includes a tundish, a crystallizer, a partition wall, a liquid barrier layer and a molten steel conveying module. The partition wall is used to separate the tundish into a first cavity and a second cavity, the first cavity is used to carry the matrix steel liquid, and the second cavity is used to carry the shell steel liquid; the liquid barrier layer is placed inside the crystallizer, and a connecting gap is opened between its edge and the inner wall of the crystallizer; there is a shell casting space above the liquid barrier layer in the crystallizer, and there is a matrix casting space below the liquid barrier layer in the crystallizer; the shell casting space is connected to the matrix casting space through the connecting gap; the molten steel conveying module includes a first flow channel and a second flow channel; the first flow channel is used to input the matrix steel liquid from the first cavity into the matrix casting space; the second flow channel is used to input the shell steel liquid from the second cavity into the shell casting space. The two molten steels are cast at the same time, so that both are in liquid state when they are compounded, and the two molten steels are combined. The characteristic of metal liquid solidifying from the outside to the inside is utilized to make the quality of the produced ingot more stable.

[0027] A continuous casting method is applicable to the above continuous casting device and also has the above beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG1 is a cross-sectional view of a continuous casting device provided in an embodiment of the present application.

[0029] FIG. 2 is a partial enlarged view of the connecting gap provided in an embodiment of the present application.

[0030] FIG3 is a flow chart of the continuous casting method provided in an embodiment of the present application.

[0031] Figure Number:

[0032] 1-tundish, 2-crystallizer, 3-isolation wall, 4-connecting gap, 5-first flow channel, 6-second flow channel, 7-base plate, 8-additional plate, 9-protrusion, 10-connecting hole, 11-through pipe, 12-floating measuring rod, 13-first flow port, 14-first throttling device, 15-second flow port, 16-second throttling device, 17-molten steel shell, 18-mixing layer, 19-transition layer, 20-protective slag, A-matrix molten steel, B-molten steel shell. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0034] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0035] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0036] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0037] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0038] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0039] Referring to FIG. 1 and FIG. 2, FIG. 1 is a cross-sectional view of the continuous casting device provided in the embodiment of the present application, and FIG. 2 is a partial enlarged view of the connecting gap provided in the embodiment of the present application. It can be seen that a continuous casting device includes: a tundish 1, a crystallizer 2, a partition wall 3, a liquid barrier layer and a molten steel conveying module. The tundish 1 and the crystallizer 2 are both implemented by conventional structures in the field of continuous casting of steel materials. The tundish 1 itself has a cavity for carrying molten steel, and the crystallizer 2 is used to receive the molten steel distributed by the tundish 1 and quickly condense the molten steel into a shape. The temperature of the crystallizer 2 can be adjusted according to actual needs. Among them, the partition wall 3 is arranged in the cavity of the tundish 1, and the bearing space in the tundish 1 is divided into a first cavity and a second cavity. The first cavity is used to carry the matrix molten steel A, and the second cavity is used to carry the shell molten steel B. The liquid barrier layer is arranged inside the crystallizer 2, and the liquid barrier layer divides the interior of the crystallizer 2 into an upper and lower layer, and the part of the crystallizer 2 located above the liquid barrier layer is defined as the shell casting space, and the part of the crystallizer 2 located below the liquid barrier layer is defined as the matrix casting space. A gap is left between the outer edge of the liquid barrier layer and the inner wall of the crystallizer 2, and the gap is defined as a connecting gap 4. The connecting gap 4 can connect the upper shell casting space with the lower base casting space, and the molten steel can flow from the shell casting space through the connecting gap 4 to the lower part.

[0040] The above-mentioned molten steel conveying module includes a first flow channel 5 and a second flow channel 6. One end of the above-mentioned first flow channel 5 is connected to the first cavity of the ladle 1, and the other end of the first flow channel 5 extends into the matrix casting space below the liquid barrier layer. The flow rate and flow velocity of the matrix molten steel A in the first flow channel 5 are controlled by controlling the opening and closing degree of the connection between the first cavity and the first flow channel 5, that is, the inlet end of the first flow channel 5, so as to continuously input the matrix molten steel A into the matrix casting space. The first flow channel 5 may need to pass through the shell casting space in the process of passing through the liquid barrier layer to connect to the matrix casting space. Therefore, the external structure of the first flow channel 5 needs to be sealed to prevent the liquid in the shell steel molten B in the shell casting space from entering. Similarly, the outer structure of the first flow channel 5 also needs to be sealed between the penetration positions of the liquid barrier layer.

[0041] One end of the second flow channel 6 is connected to the second cavity of the tundish 1, and the other end of the second flow channel 6 is connected to the shell casting space above the liquid barrier layer. By controlling the opening and closing degree of the connection between the second cavity and the second flow channel 6, that is, the inlet end of the second flow channel 6, the flow rate and flow velocity of the shell molten steel B in the second flow channel 6 are controlled, and the shell molten steel B is continuously input into the shell casting space.

[0042] When in use, a certain amount of base steel liquid A is first injected into the first cavity of the tundish 1, and a certain amount of shell steel liquid B is injected into the second cavity of the tundish 1. The crystallizer 2 is started, the inlet end of the second flow channel 6 is closed, and the inlet end of the first flow channel 5 is opened, so that the base steel liquid A enters the base casting space from the first flow channel 5. After the base steel liquid A in the base casting space reaches a certain amount, the inlet end of the second flow channel 6 is opened again, so that the shell steel liquid B enters the shell casting space. When the shell steel liquid B in the shell casting space reaches a certain amount, it will overflow and fall from the connecting gap 4, thereby first forming a steel shell 17 at the meniscus position in contact with the crystallizer 2. The incompletely solidified shell steel liquid B and the base steel liquid A will form a mixed layer 18 in the connecting gap 4. In the process of forming the mixed layer 18, both steel liquids are in liquid phase. As the molten steel continues to be injected, the mixed layer 18 will form a transition layer 19 along the inner wall of the molten steel embryo shell 17, and finally the matrix molten steel A will condense into a solidified body on the inner wall of the transition layer 19 until it is completely solidified. The molten steel is cooled in the reverse direction from outside to inside, and finally forms a firmly connected embryo shell layer on the outside of the matrix, realizing the bonding of the composite material.

[0043] After the matrix steel liquid A in the first cavity and the shell steel liquid B in the second cavity are emptied, the shell steel liquid B can just form a shell by compounding the outer wall of the matrix formed by the matrix steel liquid A. Under normal circumstances, the ratio of the amount of shell steel liquid B to the amount of matrix steel liquid A is between 1:10 and 1:2.

[0044] The present application casts two kinds of molten steel at the same time, so that both are in liquid state when they are combined, and the two kinds of molten steel are combined. The characteristic of metal liquid solidifying from the outside to the inside is utilized, and the process of first forming a solid from the internal liquid and then processing the solid outer surface is avoided, so that the quality of the produced casting is more stable.

[0045] In one embodiment of the present application, the first flow channel 5 and the second flow channel 6 are integrally formed in a double-flow channel structure, and the opening end of the first flow channel 5 and the opening end of the second flow channel 6 are staggered and connected to the shell casting space and the matrix casting space, respectively. The above-mentioned integrally formed double-flow channel structure can be set with reference to the prior art, and will not be elaborated in this article.

[0046] The thickness of the shell can be controlled by controlling the size of the connecting gap 4, adjusting the cooling intensity of the crystallizer 2, and regulating the flow rate difference between the matrix steel liquid A and the shell steel liquid B injected into the crystallizer 2. The size of the connecting gap 4 is controlled within the range of 10-50 mm (millimeter).

[0047] In one embodiment of the present application, a composite slab is cast, and plain carbon steel Q235B is preset as the matrix material, and stainless steel 304 is preset as the slab shell material. Stainless steel 304 and plain carbon steel Q235B are subjected to slab composite continuous casting, and the selected crystallizer is 300 mm (millimeters) long and 60 mm wide. Two medium frequency furnaces are started at the same time to melt 800 kg (kilograms) of stainless steel 304 and 2000 kg of plain carbon steel Q235B respectively. Liquid plain carbon steel Q235B is injected first, and liquid stainless steel 304 is injected when the liquid plain carbon steel Q235B is flush with the liquid barrier layer. The gap between the liquid barrier layer and the crystallizer 2 (that is, the connecting gap 4) is set to 10 mm, and the slab pulling speed is set to 0.5-0.8 m / min (meters per second). The slab pulling speed refers to the speed at which the cast slab is pulled out of the crystallizer 2 during the continuous casting process.

[0048] According to the experimental data, a composite slab with an outer stainless steel 304 shell thickness of 4-7mm, a transition layer of 2-3mm, a base carbon steel Q235B, a length of 300mm, and a width of 60mm can be successfully trial-produced. This application can realize one-time casting of the composite slab, effectively improve the recovery rate of molten metal, reduce costs, and improve economic benefits.

[0049] In one embodiment of the present application, the liquid barrier layer includes a substrate 7, and the communication gap 4 is provided between the side edge of the substrate 7 and the inner wall of the crystallizer 2. The substrate 7 is positioned in the crystallizer 2, and the external communication gap 4 is required. Therefore, in order to realize the positioning of the substrate 7, the substrate 7 can be fixedly connected by an external structure to stabilize it in the crystallizer 2, or the substrate 7 can be integrated into the outer structure of the first flow channel 5, which is not limited in this article.

[0050] The size and shape of the above-mentioned communication gap 4 will substantially affect the combination position and combination of the shell steel liquid B and the matrix steel liquid A. Under normal circumstances, the side edge of the substrate 7 is configured to be in the same shape as the inner wall of the crystallizer 2. If the inner wall of the crystallizer 2 forms a cylindrical structure, the side edge of the substrate 7 is also configured to be a circle of circular structure. The side edge of the substrate 7 and the inner wall of the crystallizer 2 are configured to form an annular communication gap 4, and the annular communication gap 4 is evenly opened so that the shell steel liquid B can evenly overflow the shell casting space and combine with the matrix steel liquid A. The evenly overflowed shell steel liquid B eventually forms a uniformly fitted shell on the outer wall of the matrix.

[0051] A bearing groove is provided on the top surface of the substrate 7, and the shell casting space is opened in the bearing groove. When the shell steel liquid B enters the shell casting space from the second flow channel 6, it is first stored by the bearing groove to prevent it from falling directly into the connecting gap 4. When the bearing groove is full, the shell steel liquid B will overflow naturally, and the naturally overflowing shell steel liquid B can only fall from the connecting gap 4 and combine with the base steel liquid A.

[0052] In one embodiment of the present application, the above-mentioned liquid barrier layer also includes an additional plate 8 arranged above the substrate 7. A protrusion 9 is arranged upward between the edge of the substrate 7 and the edge of the bearing groove, and the additional plate 8 covers the top of the protrusion 9, and the additional plate 8 only covers the top of the protrusion 9. A connecting hole 10 connecting the shell casting space and the connecting gap 4 is provided between the additional plate 8 and the protrusion 9. The additional plate 8 only covers the top of the protrusion 9. When too much shell steel liquid B is stored in the bearing groove, it can only overflow from the connecting hole 10 to the connecting gap 4. The size of the opening of the connecting hole 10 can control the overflow flow of the shell steel liquid B, thereby ensuring that the matrix steel liquid A is continuously input at a certain flow rate to combine with the matrix steel liquid A.

[0053] Among them, the opening position, number and size of the connecting hole 10 can be changed according to actual needs, as long as the overflow of the shell steel liquid B can form a uniform shell outside the matrix steel liquid A through the connecting gap 4, which will not be elaborated in this article.

[0054] In one embodiment of the present application, the continuous casting device further includes: a through pipe 11 extending from above the liquid barrier layer to the matrix casting space, and the through pipe 11 connects the matrix casting space to the outside of the crystallizer 2. When the liquid barrier layer is provided with a substrate 7, the through pipe 11 penetrates the substrate 7 to the inside of the matrix casting space. During the continuous casting operation, gas will inevitably exist in the matrix casting space. The through pipe 11 is used to discharge the gas in the matrix casting space, ensuring that the gas in the matrix casting space will not affect the continuous casting effect, playing an important exhaust role, and ensuring the quality of the composite continuous casting product.

[0055] A floating measuring rod 12 is arranged in the through-tube 11. The floating measuring rod 12 can move in the through-tube 11 along its length direction. One end of the floating measuring rod 12 is used to extend into the matrix casting space, and the other end of the floating measuring rod 12 extends to the outside of the through-tube 11. A scale line is arranged at the end of the floating measuring rod 12 extending to the outside of the crystallizer 2. After the first flow channel injects the matrix molten steel A into the matrix casting space, the floating measuring rod 12 is located in the matrix casting space and will float on the liquid surface of the matrix molten steel A. As the liquid surface of the matrix molten steel A rises, one end of the floating measuring rod 12 provided with the scale line will gradually extend out of the through-tube 11. The user can observe the floating rise of the floating measuring rod 12 through the scale line from the outside, thereby knowing the corresponding liquid surface height of the matrix molten steel A.

[0056] Among them, taking the composite slab as an example, the composite slab produced is very long and large in size. Therefore, the crystallizer 2 and the base plate 7 (or the liquid barrier layer) must be adaptively made large. In this way, the liquid level of the matrix steel liquid A in the matrix casting space cannot be directly observed. Therefore, the method of observing the liquid level of the matrix steel liquid A by the floating measuring rod 12 will have practical significance.

[0057] In one embodiment of the present application, a first flow opening 13 is formed on the bottom surface of the first cavity, and a first throttling member 14 for controlling the opening and closing of the first flow opening 13 is disposed in the first cavity;

[0058] A second flow opening 15 is formed on the bottom surface of the second cavity, and a second throttling member 16 for controlling the opening and closing of the second flow opening 15 is disposed in the first cavity.

[0059] In one embodiment of the present application, the first throttle member 14 is configured as a first plunger, and the second throttle member 16 is configured as a second plunger. The opening degree of the first flow port 13 can be adjusted by moving the first plunger, thereby controlling the flow rate of the matrix molten steel A entering the first flow channel 5. Similarly, the opening degree of the second flow port 15 can be adjusted by moving the second plunger, thereby controlling the flow rate of the shell molten steel B entering the second flow channel 6.

[0060] In one embodiment of the present application, the continuous casting device further comprises a gas supply mechanism, which connects the first flow channel 5 and the second flow channel 6 and is used to supply inert protective casting gas to the first flow channel 5 and the second flow channel 6 .

[0061] The inert protective pouring gas is used to prevent the molten steel from contacting with air during the pouring process and reduce oxidation. The inert protective pouring gas injected into the matrix casting space can be discharged from the through pipe 11. Adaptively, in order to facilitate the gas collection in the matrix casting space, the bottom surface of the base plate 7 can be set to a concave surface, and the concave direction is concave inward toward the center. The inert protective pouring gas in the shell casting space can be discharged upward, and if there is protective slag 20, it is discharged from the protective slag 20.

[0062] In one embodiment of the present application, the above-mentioned molten steel conveying module is configured as an integrally formed conveying pipe body, and the first flow channel 5 and the second flow channel 6 are independently opened inside the conveying pipe body; the first flow channel 5 is provided with a first connecting port connected to the base casting space, and the second flow channel 6 is provided with a second connecting port connected to the shell casting space, and the first connecting port and the second connecting port are arranged alternately. The double-flow channel conveying pipe body shell refers to the prior art, and it only needs to ensure that the first flow channel 5 and the second flow channel 6 do not affect each other during the entire transportation process, which will not be described in detail herein.

[0063] In one embodiment of the present application, the continuous casting device further comprises: a protective slag covering mechanism, which is used to cover the protective slag 20 in the casting space of the billet shell. The protective slag 20 covering the upper layer of the molten steel can achieve the effects of heat insulation, air isolation, reducing the friction between the billet and the inner wall of the crystallizer, and absorbing the floating inclusions in the molten steel, thereby purifying the molten steel. In the continuous casting process, it plays a vital role in improving the quality of the billet and ensuring smooth production.

[0064] Referring to FIG. 3 of the specification, FIG. 3 is a flow chart of a continuous casting method provided in an embodiment of the present application, wherein the continuous casting method is applicable to the above-mentioned continuous casting device, and the method comprises:

[0065] Step S1, injecting the matrix molten steel A into the first cavity, and injecting the shell molten steel B into the second cavity.

[0066] Specifically, the total amount of the matrix molten steel A and the total amount of the shell molten steel B injected are proportioned according to the requirements calculated in advance and then injected accordingly.

[0067] Step S2, opening the first flow channel 5 to allow the matrix molten steel A to flow into the matrix casting space.

[0068] Specifically, under normal circumstances, the tundish 1 is arranged above the crystallizer 2, and the first flow channel 5 drains the base molten steel A from top to bottom, and the base molten steel A flows into the base casting space by gravity.

[0069] Step S3, observe the liquid level of the above-mentioned base steel liquid A in the above-mentioned base casting space, set a preset liquid level in the crystallizer 2, and when the liquid level of the above-mentioned base steel liquid A reaches the preset liquid level, open the above-mentioned second flow channel 6 to allow the above-mentioned shell steel liquid B to flow into the above-mentioned shell casting space.

[0070] Specifically, the preset liquid level height is determined according to actual needs. After the base steel liquid A reaches the preset liquid level height, the shell steel liquid B is injected. The time difference between the two will ensure that the shell formed by the shell steel liquid B meets the needs.

[0071] Step S4, adding mold slag above the shell steel liquid B;

[0072] Step S5, continuously open the first flow channel 5 and the second flow channel 6 until the matrix molten steel A in the first cavity and the shell molten steel B in the second cavity all flow out. During this process, the shell molten steel B will flow into the matrix casting space through the connecting gap 4, so that the shell molten steel B and the matrix molten steel A are liquid-combined and solidified from the outside to the inside.

[0073] Specifically, the shell steel liquid B first forms a steel shell 17 at the meniscus position in contact with the crystallizer 2, and the incompletely solidified shell steel liquid B and the matrix steel liquid A will form a mixed layer 18 in the connecting gap 4. In the process of forming the mixed layer 18, both steel liquids are in liquid phase. The steel liquid is continuously injected, and the mixed layer 18 will form a transition layer 19 along the inner wall of the steel shell 17. Finally, the matrix steel liquid A will condense into a solidified body on the inner wall of the transition layer 19 until it is completely solidified from the outside to the inside.

[0074] In one embodiment of the present application, for the above step S2, the above first flow channel 5 is opened to allow the above matrix molten steel A to flow into the above matrix casting space; specifically, the above inert protective casting gas is introduced into the above matrix molten steel A while the above matrix molten steel A flows.

[0075] Specifically, argon is generally used as the inert protective casting gas. Argon protective casting can form an argon protective layer on the surface of the molten steel to isolate the contact between air and the molten steel, thereby preventing the molten steel from being secondary oxidized.

[0076] In one embodiment of the present application, with respect to the step S3, the liquid level of the base steel liquid A in the base casting space is observed, and when the liquid level of the base steel liquid A reaches a preset liquid level, the second flow channel 6 is opened to allow the shell steel liquid B to flow into the shell casting space;

[0077] Specifically, it includes: setting a float observation device in the above-mentioned matrix casting space, and observing the liquid level of the above-mentioned matrix steel liquid A through the above-mentioned float observation device.

[0078] The use principle of the float observation device in the matrix casting space is consistent with the conventional float structure, and the height of the matrix molten steel A liquid level is reversely observed by observing the height of the float rising in the matrix molten steel A liquid level. The actual structure and use method of the float observation device can refer to the existing technology, and this article will not elaborate on it here.

[0079] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0080] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A continuous casting device, comprising a tundish and a crystallizer, characterized in that: Also includes: A partition wall is used to separate the tundish into a first cavity and a second cavity, wherein the first cavity is used to carry the matrix steel liquid, and the second cavity is used to carry the shell steel liquid; A liquid barrier layer is disposed inside the crystallizer, and a connecting gap is formed between the edge of the liquid barrier layer and the inner wall of the crystallizer; a blank shell casting space is provided above the liquid barrier layer in the crystallizer, and a matrix casting space is provided below the liquid barrier layer in the crystallizer; the blank shell casting space is connected to the matrix casting space through the connecting gap; The molten steel conveying module comprises a first flow channel and a second flow channel; one end of the first flow channel is connected to the first cavity, and the other end passes through the liquid barrier layer and is connected to the matrix casting space, so as to transfer the matrix molten steel from the first cavity to the matrix casting space; One end of the second flow channel is connected to the second cavity, and the other end is connected to the shell casting space, and is used to transfer the shell molten steel from the second cavity to the shell casting space.

2. The continuous casting device according to claim 1, characterized in that: The liquid barrier layer comprises a substrate positioned inside the crystallizer, and the connecting gap is provided between the side edge of the substrate and the inner wall of the crystallizer; a bearing groove is provided on the top surface of the substrate, and the blank shell casting space is provided in the bearing groove.

3. The continuous casting device according to claim 2, characterized in that: The liquid isolation layer also includes an additional plate arranged above the substrate, and the substrate is provided with a protrusion between its edge and the edge of the bearing groove; the additional plate covers the protrusion; a connecting hole is opened between the protrusion and the additional plate; the two ends of the connecting hole are respectively connected to the blank shell casting space and the connecting gap.

4. The continuous casting device according to claim 1, characterized in that: Also includes: A through pipe extends from above the liquid barrier layer into the matrix casting space; the through pipe connects the matrix casting space to the outside of the crystallizer; a floating measuring rod is arranged in the through pipe, and the end of the floating measuring rod can extend along the through pipe to the outside of the crystallizer, and a scale line is arranged on the end of the floating measuring rod.

5. The continuous casting device according to claim 1, characterized in that: A first flow opening is formed on the bottom surface of the first cavity, and a first throttling member for controlling the opening and closing of the first flow opening is disposed in the first cavity; A second flow opening is formed on the bottom surface of the second cavity, and a second throttling member for controlling the opening and closing of the second flow opening is disposed in the first cavity.

6. The continuous casting device according to claim 1, characterized in that: Also includes: A gas delivery mechanism is connected to the first flow channel and the second flow channel, and is used to introduce inert protective casting gas into the first flow channel and the second flow channel.

7. The continuous casting device according to claim 1, characterized in that: The molten steel conveying module is configured as an integrally formed conveying pipe body, and the first flow channel and the second flow channel are independently opened inside the conveying pipe body respectively; the first flow channel is provided with a first connecting port connected to the base casting space, and the second flow channel is provided with a second connecting port connected to the shell casting space, and the first connecting port and the second connecting port are staggered.

8. A continuous casting method, applicable to the continuous casting device according to claims 1 to 7, characterized in that: Methods include: Injecting the matrix molten steel into the first cavity, and injecting the shell molten steel into the second cavity; Opening the first flow channel to allow the matrix molten steel to flow into the matrix casting space; Observing the liquid level of the matrix steel liquid in the matrix casting space, setting a preset liquid level in the crystallizer, and when the liquid level of the matrix steel liquid reaches the preset liquid level, opening the second flow channel to allow the shell steel liquid to flow into the shell casting space; Adding protective slag above the molten steel of the shell; The first flow channel and the second flow channel are continuously opened until the matrix steel liquid in the first cavity and the shell steel liquid in the second cavity are completely flowed out. During this process, the shell steel liquid will flow into the matrix casting space through the connecting gap, so that the shell steel liquid and the matrix steel liquid are combined and solidified from the outside to the inside.

9. The continuous casting method according to claim 8, characterized in that: Opening the first flow channel to allow the matrix molten steel to flow into the matrix casting space includes: introducing the inert protective casting gas into the matrix molten steel while the matrix molten steel flows.

10. The continuous casting method according to claim 8, characterized in that: Observing the liquid level of the base steel liquid in the base casting space, and when the liquid level of the base steel liquid reaches a preset liquid level, opening the second flow channel to allow the shell steel liquid to flow into the shell casting space, comprising: A float observation device is arranged in the matrix casting space, and the liquid level of the matrix molten steel is observed through the float observation device.

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