Device, system and method for reducing center segregation of continuous casting billet

Abstract

The invention discloses a device, system and method for reducing center segregation of a continuous casting billet, the device is fixed on a continuous casting machine, the device comprises a fixing frame, and a guide groove is formed in the fixing frame; the fixed block is fixed in the middle area of the guide groove, and the two movable blocks are slidably connected into the guide groove in the two sides of the fixed block respectively; the linear driving unit drives the moving block to move in the guide groove; one end of the rapping device is fixed on the fixed block or the movable block, the other end of the rapping device is provided with a roller sleeve parallel to the width direction of the pouring cambered surface, and the roller sleeve is attached to the surface of the continuous casting billet; under the action of the rapping device, the stick sleeve is rapped on the arc-shaped surface at a certain amplitude and frequency; the vibration of the solidification tail end of the casting blank is realized, and the problem of center segregation of the solidification tail end of the casting blank is solved. In the continuous casting process, the position of the moving block is adjusted through the linear driving unit according to the section of a cast steel grade, the position of the rapping device is indirectly adjusted, and the effect of avoiding center segregation through rapping under different section conditions is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of continuous casting, and particularly to a device, a system and a method for reducing the central segregation of continuous casting billets. Background Art

[0002] Continuous casting is the core process of converting molten steel into casting billets. During the solidification process of molten steel, solute elements will redistribute between the solid-liquid phases. Elements such as carbon, manganese, and sulfur have different solubilities in the solid and liquid phases. During the growth of columnar crystals, the solute elements precipitated from the columnar crystals will be discharged into the unfrozen molten metal. As the crystallization continues, these enriched solute elements are pushed towards the central part that solidifies last, resulting in central segregation.

[0003] The central segregation of continuous casting billets will cause harm to the quality of steel and subsequent processing. Especially due to the uneven composition at the central segregation, the strength of different parts of the casting billet will show differences. When stressed, the segregation area with lower strength is prone to become a weak point, resulting in premature deformation or even fracture of the part, reducing the reliability and service life of the product. At the same time, due to the uneven hardness and toughness of the central segregation, local stress concentration will occur during the cold deformation processing of the material, leading to deterioration of the cold working performance, such as cold brittleness, affecting the dimensional accuracy and surface quality of the product. Therefore, it is crucial to avoid and solve the problem of central segregation of continuous casting billets.

[0004] In the prior art, there are various solutions to the problem of central segregation of continuous casting billets, but there are some problems with all of them.

[0005] Solution 1 provides a dynamic soft reduction process for continuous casting of heavy rail steel blooms. This process can be applied to the continuous casting of high-carbon steel blooms. It can not only significantly reduce defects such as central segregation, central porosity, central shrinkage cavity, and central crack, prevent internal cracks such as central cracks and intermediate cracks in the casting billet, but also improve the composition uniformity of the rails rolled from the continuous casting billet, stabilize and improve the mechanical properties and service performance of the rails, meeting the technical requirements of high-speed rails. The technical measures are as follows: controlling the continuous casting drawing speed and molten steel temperature of heavy rail steel, with the continuous casting drawing speed being 0.60 - 0.80 m / min and the superheat of molten steel being 15 - 40 °C; adopting a uniform and gentle control method in the secondary cooling area, with the continuous casting specific water consumption being 0.25 - 0.30 L / kg and the surface temperature of the continuous casting billet in the soft reduction area being 900 - 1020 °C; controlling the reduction amount in the soft reduction area, with the solidification rate fs of the casting billet in the soft reduction area being 30% - 100% and the total reduction amount being 1.6 - 7.0 mm. This method mainly reduces the central segregation problem through the optimized setting of process parameters, but it cannot solve the rapid solidification at the end of the accelerated liquid core solidification, and the central segregation problem is not fundamentally solved.

[0006] Solution 2 provides a method for directly intervening in the internal quality of the continuous casting billet. This method inserts a thin metal strip into the molten steel in the mold through a feeding device, and the thin strip can vibrate at an appropriate frequency and amplitude. By controlling the insertion method and speed of the thin strip, this method can directly intervene in the internal solidification and crystallization mechanism, reduce the superheat of the molten steel in the mold, shorten the depth of the liquid phase cavity, reduce columnar crystals, increase the proportion of equiaxed crystals, improve the solidification structure of the continuous casting billet, reduce central segregation, and thus improve the Z-direction plasticity and impact toughness of the steel, and increase the flaw detection qualification rate of large specifications. This aspect is only theoretically feasible, but it is difficult to insert the thin metal strip at a suitable position in the molten steel in the mold, and the implementability is not high.

[0007] Solution 3 provides an electroslag casting device and method with external electromagnetic stirring, which mainly includes a mold, a mold water jacket, and an electromagnetic stirrer. An annular magnet is sleeved on the outer wall of the mold, and the annular magnet is located in the upper-middle part of the mold. A coil is wound around the iron core of the annular magnet. An electromagnetic stirrer water jacket is arranged around the annular electromagnet, and the electromagnetic stirrer water jacket is communicated with the mold water jacket; the melted consumable electrode forms molten steel droplets and enters the slag layer. Under the action of the externally applied rotating electromagnetic field, the molten steel droplets fall in a spiral manner in the slag layer and enter the molten steel ingot pool. The molten steel ingot pool continuously rises and also enters the effective magnetic field action area of the electromagnetic stirrer. At this time, the current in the molten steel and the rotating magnetic field act to generate an electromagnetic force to drive the molten steel to rotate; this device is mainly applicable to the electroslag casting method and is not applicable to the central segregation problem under the conventional continuous casting process. Summary of the Invention

[0008] In view of the above-mentioned defects existing in the prior art, a device, system and method for reducing central segregation of continuous casting billets are provided. By setting a vibration striking device, the problem of central segregation during continuous casting is avoided.

[0009] The technical solutions adopted by the present invention to solve the above technical problems are as follows: In a first aspect, a device for reducing central segregation of continuous casting billets, the device is fixed on a continuous casting machine, and the device includes A fixing frame is installed on the continuous casting machine. At least one guiding groove perpendicular to the pouring direction of the continuous casting machine is provided on the fixing frame, and a through groove is provided on the side of the guiding groove facing the pouring arc surface of the continuous casting machine; A fixing block, a moving block, and a linear driving unit. The fixing block is fixed in the middle area of the guiding groove, and the two moving blocks are respectively slidably connected in the guiding grooves on both sides of the fixing block; the linear driving unit drives the moving block to move in the guiding groove; The vibration device, one end of the vibration device is fixed on the fixed block or the moving block, and the vibration devices in each guide groove are grouped together; The middle part of the vibration device passes through the through groove and the gap between two adjacent continuous casting rollers of the continuous casting machine, and the other end of the vibration device is provided with a roller sleeve parallel to the width direction of the casting arc surface, and the roller sleeve fits on the surface of the continuous casting billet; Under the action of the vibration device, the roller sleeve vibrates on the arc surface with a certain amplitude and frequency. During the continuous casting process, according to the information of the steel grade, the position of the moving block and the amplitude and frequency of each vibration device are adjusted.

[0010] According to the above technical solution, the fixed frame has a certain arc-shaped frame, and its arc is consistent with the casting arc of the continuous casting machine; A plurality of guide grooves are arranged on the fixed frame, and the vibration devices in each guide groove are located between two adjacent continuous casting rollers.

[0011] According to the above technical solution, the vibration device includes a telescopic rod, a shaft core, a roller sleeve and a limiting component. One end of the telescopic rod is fixed on the moving block or the fixed block, and the other end of the telescopic rod passes through the through groove and the gap between two adjacent continuous casting rollers. The shaft core is fixed on the other end of the telescopic rod; The core shaft is parallel to the width direction of the surface of the continuous casting billet, the roller sleeve is rotatably sleeved on the core shaft, and the limiting components are installed at both ends of the roller sleeve to limit the axial movement of the roller sleeve along the core shaft.

[0012] According to the above technical solution, the linear drive unit includes an optical axis, several bearings supporting the optical axis, and a rotary drive system for driving the optical axis to rotate; There is a through hole on the fixed block, the optical axis passes through the through hole, and the optical axis is installed on the fixed frame through bearings at multiple places; Opposite external threads are provided at both ends of the optical axis located on the fixed block, and matching threaded holes are provided on the corresponding moving blocks.

[0013] According to the above technical solution, the fixed block and the fixed frame are integrally designed; Alternatively, the fixed block is slidably connected in the guide groove, and is connected by a pin hole and a pin or a bolt connection between the fixed block and the fixed frame.

[0014] According to the above technical solution, four guide grooves perpendicular to the casting direction of the continuous casting machine are arranged on the fixed frame; The multiple groups of vibration devices on the same fixed frame and the continuous casting rollers of the continuous casting machine are alternately arranged.

[0015] In the second aspect, a system for reducing the central segregation of the continuous casting billet, multiple sector segments are respectively designed on the upper and lower sides of the continuous casting billet, and each sector segment is provided with multiple pairs of continuous casting rollers; It includes a liquid core detection system and multiple devices for reducing the central segregation of the continuous casting billet as described in any one of the above; One or more devices for reducing the central segregation of the continuous casting billet are installed on a sector segment; The liquid core detection system is used to detect the position of the end of the liquid core solidification in real time.

[0016] Thirdly, a method for reducing the central segregation of continuous casting billets is applied to the system for reducing the central segregation of continuous casting billets described above. The method includes: Obtaining the casting section width L of the continuous casting billet; Based on the casting section width L, adjusting the position of the moving block in the guiding groove; After the length of the continuous casting billet reaches the set value, obtaining the position of the end of the liquid core solidification; Based on confirming the position of the end of the liquid core solidification and identifying the type of steel grade, obtaining a continuous multi-group of vibration hammering devices as the actual working units, and obtaining the working frequency and vibration amplitude of each group of vibration hammering devices within the actual working units; Executing the working frequency and vibration amplitude of each group of vibration hammering devices within the actual working units; End the casting and close the system for reducing the central segregation of continuous casting billets.

[0017] According to the above technical solution, select a continuous multi-group of vibration hammering devices, number each group of vibration hammering devices in the opposite direction of casting, and number them 1 to n in sequence; the vibration amplitude of the vibration hammering devices decreases in sequence from n to 1, and the vibration frequency increases in sequence.

[0018] According to the above technical solution, the moving block moves to the area of 0.25L and 0.75L of the casting section width; Or / and, n takes the value of 5, When the steel grade is low-carbon steel, the 1-3rd vibration hammering devices are put into use. Among them, the vibration amplitude of the 1st vibration hammering device is 1.7 mm to 2.3 mm, and the vibration frequency is 77 Hz to 83 Hz; the vibration amplitude of the 2nd vibration hammering device is 2.7 mm to 3.3 mm, and the vibration frequency is 57 Hz to 63 Hz; the vibration amplitude of the 3rd vibration hammering device is 3.7 mm to 4.3 mm, and the vibration frequency is 37 Hz to 43 Hz; When the steel grade is medium-carbon steel, the 1-4th vibration hammering devices are put into use. Among them, the vibration amplitude of the 1st vibration hammering device is 1.7 mm to 2.3 mm, and the vibration frequency is 57 Hz to 63 Hz; the vibration amplitude of the 2nd vibration hammering device is 2.7 mm to 3.3 mm, and the vibration frequency is 37 Hz to 43 Hz; the vibration amplitude of the 3rd vibration hammering device is 2.7 mm to 3.3 mm, and the vibration frequency is 17 Hz to 23 Hz; the vibration amplitude of the 4th vibration hammering device is 3.7 mm to 4.3 mm, and the vibration frequency is 7 Hz to 13 Hz; When the steel grade is high-carbon steel or other steel grades, the 1st to 5th rapping devices are put into use. Among them, the rapping amplitude of the 1st rapping device is 1.2 mm to 1.8 mm, and the rapping frequency is 47 Hz to 53 Hz; the rapping amplitude of the 2nd rapping device is 1.7 mm to 2.3 mm, and the rapping frequency is 40 Hz; the rapping amplitude of the 3rd rapping device is 2.2 mm to 2.8 mm, and the rapping frequency is 27 Hz to 33 Hz; the rapping amplitude of the 4th rapping device is 2.7 mm to 3.3 mm, and the rapping frequency is 17 Hz to 23 Hz; the rapping amplitude of the 5th rapping device is 2.7 mm to 3.3 mm, and the rapping frequency is 7 Hz to 13 Hz.

[0019] The present invention has the following beneficial effects: 1. Install a device for reducing the central segregation of continuous casting billets on the continuous caster to form high-frequency vibration; it can achieve rapping on the solidification end of the casting billet and solve the problem of central segregation at the solidification end of the casting billet. In addition, a plurality of guide grooves are provided on the fixed frame, and two moving blocks are provided in the guide grooves; according to the cross-section of the casting steel grade, the position of the moving blocks is adjusted through the linear drive unit, indirectly realizing the adjustment of the position of the rapping device, and improving the effect of avoiding central segregation through rapping under different cross-section conditions.

[0020] 2. Based on the information of the steel grade and the width of the continuous casting billet, adjust the position, rapping frequency and rapping amplitude of the rapping mechanism, which meets the adaptability of the system to different steel grades and greatly improves the quality of the steel grade.

[0021] 3. In the system, install one or more devices for reducing the central segregation of continuous casting billets on a segment. The whole device is installed on the segment and can be replaced integrally with the segment, which is convenient for installation and disassembly. And the device for reducing the central segregation of continuous casting billets has the characteristics of simple structure, low price and strong applicability.

[0022] 4. Since the contact part between the whole rapping device and the continuous casting billet is a roller sleeve, and the roller sleeve can rotate freely on the mandrel; during the rapping process, the frictional force between the continuous casting billet and the roller sleeve can only drive the roller sleeve to rotate and cannot be transmitted to the mandrel and the telescopic rod, which can reduce the rapping resistance caused by the inconsistent drawing direction and rapping direction, and improve the service life of the equipment.

[0023] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly and implement it according to the content of the specification, the following takes the preferred embodiments of the present invention and combines the drawings to describe in detail as follows. The specific implementation manners of the present invention are given in detail by the following embodiments and their drawings. Description of the Drawings

[0024] The accompanying drawings described herein are used to provide a further understanding of the present invention and form a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0025] Figure 1 is a schematic installation view of the device for reducing the central segregation of continuous casting billets provided by the present invention; Figure 2 is a side view of the device for reducing the central segregation of continuous casting billets provided by the present invention; Figure 3 is a front view of the device for reducing the central segregation of continuous casting billets provided by the present invention; Figure 4 is Figure 2 a cross-sectional view taken along A-A in Figure 5 is a schematic view of the contact between the device for reducing the central segregation of continuous casting billets provided by the present invention and the continuous casting billet; In the figure, 1, fixed frame; 2, guide groove; 3, fixed block; 4, moving block; 5, linear drive unit; 5-1, optical axis; 5-2, bearing; 5-3, rotary drive system; 5-4, sealing plate; 5-5, cover plate; 6, vibration device; 6-1, telescopic rod; 6-2, shaft core; 6-3, roller sleeve; 6-4, limit component; 6-41, stop block; 6-42, end cover; 7, continuous casting roll; 8, bolt; 9, external billet shell; 10, central billet liquid core; A, pouring direction of the continuous casting machine. Detailed implementation manners

[0026] The following Figures 1-5 describes the principles and features of the present invention with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention. In the following paragraphs, the present invention will be described more specifically by way of example with reference to the accompanying drawings. The advantages and features of the present invention will be clearer according to the following description and claims. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise scales, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0027] It should be noted that when a component is referred to as "fixed to" another component, it can be directly on the other component or there may also be an intermediate component. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component at the same time. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the specification of this invention are for the purpose of describing specific embodiments only and are not intended to limit the invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0029] Referring to Figures 1 to 5 as shown, the device for reducing the central segregation of continuous casting billets provided by the present invention. The device is fixed on a continuous casting machine, and the device includes: A fixing frame 1, on which there is at least one guiding groove 2 perpendicular to the pouring direction A of the continuous casting machine. The guiding groove is provided with a through groove 2-1 on the side facing the pouring arc surface of the continuous casting machine; the through groove is used to communicate the guiding groove with the external space and is used to pass through the vibration striking device.

[0030] A fixing block 3, a moving block 4, and a linear driving unit 5. The fixing block is fixed in the middle area of the guiding groove, and the two moving blocks are respectively slidably connected in the guiding grooves on both sides of the fixing block; the linear driving unit drives the moving block to move in the guiding groove; A vibration striking device 6, one end of the vibration striking device is fixed on the fixing block or the moving block, and the vibration striking devices of each guiding groove are in a group; the middle part of the vibration striking device passes through the through groove and the gap between two adjacent continuous casting rolls 7 of the continuous casting machine, and the other end of the vibration striking device is provided with a roller sleeve parallel to the width direction of the pouring arc surface, and the roller sleeve fits on the surface of the continuous casting billet; under the action of the vibration striking device, the roller sleeve vibrates on the arc surface with a certain amplitude and frequency; During the continuous casting process, according to the information of the steel grade, the position of the moving block and the amplitude and frequency of each vibration striking device are adjusted.

[0031] In some embodiments, a preferred structural form of the vibration striking device is given. The vibration striking device includes a telescopic rod 6-1, a shaft core 6-2, a roller sleeve 6-3, and a limiting component 6-4. One end of the telescopic rod is fixed on the moving block or the fixing block, and the other end of the telescopic rod passes through the through groove and the gap between two adjacent continuous casting rolls. The shaft core is fixed on the other end of the telescopic rod; the core shaft is parallel to the width direction of the surface of the continuous casting billet, the roller sleeve is rotatably sleeved on the core shaft, and the limiting component is installed at both ends of the roller sleeve to limit the axial movement of the roller sleeve along the core shaft. Among them, the core shaft is mainly used to connect the roller sleeve with the telescopic rod. Under the action of the limiting component, the roller sleeve can only rotate on the core shaft and cannot move axially. The roller sleeve is mainly used to vibrate the casting billet during the billet drawing process. The limiting component includes a stop block 6-41 and an end cover 6-42, and the stop block is positioned and installed by using the limiting component.

[0032] In this structure, the rapping device reciprocates and retracts the telescopic rod at high frequency, so that the mandrel reciprocates and raps the surface of the continuous casting billet within a certain range, forming high-frequency vibration; it can realize the rapping of the solidification end of the casting billet, and solve the problem of center segregation at the solidification end of the casting billet. In addition, since the contact part between the entire rapping device and the continuous casting billet is the roller sleeve, and the roller sleeve can rotate freely on the mandrel; during the rapping process, the friction between the continuous casting billet and the rod sleeve can only drive the rod sleeve to rotate, and cannot be transmitted to the mandrel and the telescopic rod, which can reduce the rapping resistance caused by the inconsistency between the billet drawing direction and the rapping direction, and improve the service life of the equipment.

[0033] Other forms of rapping structures with other power sources can also be used to replace the telescopic rod, such as a mechanical rapping device (driving the core shaft and the stick sleeve to produce periodic vibration or impact through mechanical transmission (such as eccentric wheel, cam, connecting rod mechanism)), an electromagnetic rapping device (using the magnetic force generated after the electromagnetic coil is energized to drive the core shaft and the stick sleeve), a vibration motor rapping device (using the motor to drive the eccentric block to rotate to generate centrifugal force, driving the core shaft and the stick sleeve to produce periodic vibration or impact), a pneumatic rapping device (using compressed air to drive the piston or airbag to generate impact force, driving the core shaft and the stick sleeve to produce periodic vibration or impact), etc.

[0034] In some embodiments, a preferred structural form of a linear drive unit is provided. The linear drive unit includes an optical axis 5-1, a plurality of bearings 5-2 supporting the optical axis, and a rotation drive system 5-3 driving the optical axis to rotate; a through hole is provided on the fixed block, the optical axis passes through the through hole, and the optical axis is mounted on the fixed frame through bearings at multiple locations; opposite external threads are provided at both ends of the optical axis located on the fixed block, and matching threaded holes are provided on the corresponding moving block.

[0035] A moving block is designed on the left side of the fixed block, a threaded hole with a left thread is designed at the center of the moving block, and the moving block can be installed on the left threaded section of the optical axis through the threaded hole; a moving block is also designed on the right side of the fixed block, a threaded hole with a right thread is designed at the center of the moving block, and the moving block can be installed on the right threaded section of the optical axis through the threaded hole.

[0036] Since the optical axis is connected to the rotation drive system, and one end of the rotation drive system is fixed on the fixed frame; when the rotation drive system rotates, the middle fixed block will not move left and right, and the left and right moving blocks will move towards or away from each other at the same time under the action of the left thread and the right thread. In this way, the precise adjustment of the positions of different moving blocks in the concave guide groove can be achieved through a rotation drive system.

[0037] In the above structure, the rotation drive system can be directly connected to the motor or adopt the structural form of a motor and a reducer. The rotation system is used to drive the optical axis to rotate; the transmission form of the lead screw and nut is used to synchronously drive the two moving blocks on both sides to approach or move away from each other in the guide groove.

[0038] Bearings are respectively designed on both sides of the fixed block, and bearings are also respectively provided at both ends of the mounting bracket; mainly used to reduce the rotational movement resistance of the rotating mechanism. A sealing plate 5-4 is provided outside the bearing at the fixed block, mainly used to fix and position the bearing; cover plates 5-5 are provided at both ends of the fixed frame, and the cover plates are used to block both ends of the guide groove, and bearings are provided on the cover plates.

[0039] In the above structure, the moving blocks located in the same guide groove are synchronously driven, or can be separately driven by a linear drive unit. In addition, the transmission form of the lead screw and bolt pair can be replaced with the transmission form of a gear and rack, and even an electric push rod can be used, as long as it can drive the existing structure of the moving block to move linearly in the guide groove.

[0040] In the above structure, there are two connection methods between the fixed block and the guide groove.

[0041] One is that the fixed block and the fixed frame are integrally designed. At this time, the guide groove is divided into a left half section and a right half section by the fixed block, and the two moving blocks are respectively slidably connected in the left half section and the right half section.

[0042] The second is that the fixed block is slidably connected in the guide groove, and is connected by a pin hole and a pin or a bolt 8 between the fixed block and the fixed frame. In Embodiment 2, the fixed block and the moving block have the same size and can both be slidably connected in the guide groove; after the fixed block slides to the middle position of the guide groove, the fixed block is fixed to the middle of the guide groove through a pin hole and a pin or a bolt connection, and the vibration hammer assembly located in the middle is fixed on the fixed block.

[0043] After adopting any combination of the above structures, it is divided into two embodiments: Embodiment 1 Four guide grooves perpendicular to the pouring direction of the continuous casting machine are provided on the fixed frame; multiple sets of vibration hammer devices on the same fixed frame and the continuous casting rollers of the continuous casting machine are alternately arranged.

[0044] In this embodiment, one fixed frame is provided with 4 guide grooves, corresponding to four groups of vibration hammer devices. When multiple guide grooves are provided on one fixed frame, the fixed frame has a certain arc, and its arc is consistent with the pouring arc of the continuous casting machine; when multiple guide grooves are provided on the fixed frame, the vibration hammer devices in each guide groove are located between two adjacent continuous casting rollers.

[0045] Embodiment 2 A guide groove perpendicular to the casting direction of the continuous casting machine is arranged on each fixed frame; a plurality of fixed frames are arranged on the continuous casting machine at intervals. In this embodiment, one fixed frame is provided with one guide groove, corresponding to one set of rapping devices.

[0046] The present invention also provides a system for reducing the center segregation of the continuous casting billet. The upper and lower sides of the continuous casting billet are respectively designed with multiple fan-shaped segments, and each fan-shaped segment is provided with multiple pairs of continuous casting rollers. Under the combined effect of the secondary cooling water condensation of the fan-shaped segments (not shown in the figure, existing structure) and the pressure of the continuous casting rollers, the continuous casting billet is gradually cooled, the outer billet shell 9 of the continuous casting billet is gradually thickened, and the liquid core 10 of the middle part of the continuous casting billet is gradually shrunk and formed. The device also includes a liquid core detection system and a plurality of devices for reducing the center segregation of the continuous casting billet as described above; one or more devices for reducing the center segregation of the continuous casting billet are installed on a sector segment, and the entire device is installed on the sector segment and can be replaced as a whole together with the sector segment, and is easy to install and disassemble; the liquid core detection system is used to detect the end position of the liquid core solidification in real time.

[0047] The present invention also provides a method for reducing the center segregation of a continuous casting billet, which is applied to the above-mentioned system for reducing the center segregation of a continuous casting billet, and the method comprises: Step 1: When the system receives the "start pouring" command, it starts and reads the casting section width L from the continuous casting machine; then controls the rotation of the rotary drive system, adjusts the position of the left and right moving blocks in each guide groove to a position where the center line of its rapping device is L / 4 away from the edge of the continuous casting billet, and then fixes it.

[0048] Step 2: The casting system tracks the position of the ingot in real time. When the length of the ingot reaches 1 / 2 of the length of the working area of ​​the continuous casting machine, the liquid core detection system is put into use to detect the end position of the liquid core solidification in real time, and calculate the continuous casting roller numbers k and k-1 where the liquid core solidification end position is located (the continuous casting roller numbers are numbered along the casting direction, with the starting number being 1, followed by 1, 2, 3, 4...n).

[0049] Step 3: According to the continuous casting roller numbers k and k-1, find the device for reducing the central segregation of the continuous casting billet installed on the fan-shaped segment, and find the rapping device between the continuous casting rollers k and k-1, number it as 1, and number the five rapping devices in the opposite direction of casting, as 1, 2, 3, 4, and 5 respectively.

[0050] Step 4: The system automatically reads the steel type information.

[0051] When the steel grade is low carbon steel, rapping devices No. 1-3 are put into use, among which the rapping amplitude of rapping device No. 1 is 2mm, and the rapping frequency is 80Hz; the rapping amplitude of rapping device No. 2 is 3mm, and the rapping frequency is 60Hz; the rapping amplitude of rapping device No. 3 is 4mm, and the rapping frequency is 40Hz.

[0052] When the steel grade is medium carbon steel, No. 1-4 vibration devices are put into use, among which the vibration amplitude of No. 1 vibration device is 2mm, and the vibration frequency is 60Hz; the vibration amplitude of No. 2 vibration device is 3mm, and the vibration frequency is 40Hz; the vibration amplitude of No. 3 vibration device is 3mm, and the vibration frequency is 20Hz; the vibration amplitude of No. 4 vibration device is 4mm, and the vibration frequency is 10Hz.

[0053] When the steel grade is high carbon steel or other steel grades, the vibration devices No. 1 to No. 5 are put into use, among which the vibration amplitude of the vibration device No. 1 is 1.5mm and the vibration frequency is 50Hz; the vibration amplitude of the vibration device No. 2 is 2mm and the vibration frequency is 40Hz; the vibration amplitude of the vibration device No. 3 is 2.5mm and the vibration frequency is 30Hz; the vibration amplitude of the vibration device No. 4 is 3mm and the vibration frequency is 20Hz; the vibration amplitude of the vibration device No. 5 is 3mm and the vibration frequency is 10Hz; Step 5: When the system receives the "casting end" command, it automatically detects the position of the tail billet. When the tail billet is ≤2m away from the No. 5 vibration device, the vibration system stops running and the system is shut down.

[0054] The invention patent develops a device and method for reducing the center segregation of continuous casting billets. The overall system structure is simple, low-cost, and highly applicable. The entire device is installed on the fan-shaped segment and can be replaced as a whole together with the fan-shaped segment, which is convenient to install and disassemble. A plurality of rapping devices are designed on the device for reducing the center segregation of continuous casting billets. The system can automatically match different rapping process parameters according to the information of the steel grade, which meets the adaptability of the system to different steel grades and greatly improves the quality of the steel grade. A plurality of concave guide grooves are designed on the device for reducing the center segregation of continuous casting billets, and a plurality of moving blocks are designed in the concave guide grooves. Through different threads on the left and right sides of an optical axis on a rotating mechanism and under the action of a rotating drive system, the position of the moving block can be adjusted according to the cross-section of the casting steel grade, thereby improving the effect of avoiding center segregation through rapping under different cross-section conditions. The entire rapping wheel is a roller sleeve structure. Since the roller sleeve can rotate freely on the mandrel, the rapping resistance caused by the inconsistency between the billet drawing direction and the rapping direction is reduced, thereby improving the service life of the equipment.

[0055] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in the industry can smoothly implement the present invention as shown in the drawings and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. Apparatus for reducing central segregation of continuous casting billets, characterized in that: The device is fixed on a continuous casting machine, and the device includes a fixing frame which is installed on the continuous casting machine. At least one guiding groove perpendicular to the casting direction of the continuous casting machine is provided on the fixing frame, and a through groove is provided on the side of the guiding groove facing the casting arc surface of the continuous casting machine; a fixing block, a moving block, and a linear driving unit. The fixing block is fixed in the middle area of the guiding groove, and the two moving blocks are respectively slidably connected in the guiding grooves on both sides of the fixing block; the linear driving unit drives the moving block to move in the guiding groove; a vibration device, one end of the vibration device is fixed on the fixing block or the moving block, and the vibration devices of each guiding groove form a group; the middle part of the vibration device passes through the through groove and the gap between two adjacent continuous casting rolls of the continuous casting machine, and a rod sleeve parallel to the width direction of the casting arc surface is provided at the other end of the vibration device, and the rod sleeve is attached to the surface of the continuous casting billet; under the action of the vibration device, the rod sleeve vibrates on the arc surface with a certain amplitude and frequency; During continuous casting, according to the information of the steel grade, the position of the moving block, and the amplitude and frequency of each vibration device are adjusted.

2. The device for reducing the central segregation of continuous casting billets according to claim 1, characterized in that: The fixing frame has a certain arc-shaped frame, and its arc is consistent with the casting arc of the continuous casting machine; a plurality of guiding grooves are provided on the fixing frame, and the vibration devices in each guiding groove are located between two adjacent continuous casting rolls.

3. The device for reducing the central segregation of continuous casting billets according to claim 1 or 2, characterized in that: The vibration device includes a telescopic rod, a shaft core, a rod sleeve, and a limiting component. One end of the telescopic rod is fixed on the moving block or the fixing block, and the other end of the telescopic rod passes through the through groove and the gap between two adjacent continuous casting rolls. The shaft core is fixed on the other end of the telescopic rod; the core shaft is parallel to the width direction of the surface of the continuous casting billet, the rod sleeve is rotatably sleeved on the core shaft, and the limiting component is installed at both ends of the rod sleeve to limit the axial movement of the rod sleeve along the core shaft.

4. The device for reducing the central segregation of continuous casting billets according to claim 1 or 2, characterized in that: The linear driving unit includes an optical axis, several bearings for supporting the optical axis, and a rotary driving system for driving the optical axis to rotate; a through hole is provided on the fixing block, the optical axis passes through the through hole, and the optical axis is installed on the fixing frame through bearings at multiple places; opposite external threads are provided at both ends of the optical axis located on the fixing block, and matching threaded holes are provided on the corresponding moving blocks.

5. The device for reducing the central segregation of continuous casting billets according to claim 1, characterized in that: The fixing block and the fixing frame are integrally designed; or, the fixing block is slidably connected in the guiding groove, and is connected by a pin hole and a pin or a bolt connection between the fixing block and the fixing frame.

6. The device for reducing the central segregation of continuous casting billets according to claim 1, characterized in that: Four guiding grooves perpendicular to the casting direction of the continuous casting machine are provided on the fixing frame; multiple groups of vibration devices on the same fixing frame and the continuous casting rolls of the continuous casting machine are alternately arranged.

7. A system for reducing the central segregation of continuous casting billets, with multiple segmental rolls designed on the upper and lower sides of the continuous casting billet respectively, and each segmental roll is provided with multiple pairs of continuous casting rolls; characterized in that: It includes a liquid core detection system and multiple devices for reducing the center segregation of the continuous casting billet as described in any one of claims 1-5; one or more devices for reducing the center segregation of the continuous casting billet are installed on a segment; the liquid core detection system is used to detect the position of the end of the liquid core solidification in real time.

8. Method for reducing central segregation of continuous casting billet, characterized in that: Applied to the system for reducing the center segregation of the continuous casting billet as described in claim 7 above, the method includes: Obtaining the casting section width L of the continuous casting billet; Based on the casting section width L, adjusting the position of the moving block in the guiding groove; After the length of the continuous casting billet reaches the set value, obtaining the position of the end of the liquid core solidification; Based on confirming the position of the end of the liquid core solidification and identifying the category of the steel grade, obtaining multiple consecutive groups of vibration devices as the actual working units, and obtaining the working frequency and vibration amplitude of each group of vibration devices in the actual working units; Execute the working frequency and amplitude of each group of rapping devices within the actual working unit. End the pouring and shut down the system for reducing the central segregation of continuous casting billets.

9. The method for reducing the central segregation of continuously cast billets according to claim 8, characterized in that: Select multiple consecutive groups of rapping devices, number each group of rapping devices in the opposite direction of casting, and sequentially number them from 1 to n; the rapping amplitude of the rapping devices decreases sequentially from n to 1, and the rapping frequency increases sequentially.

10. The method for reducing the central segregation of continuous casting billets according to claim 8, characterized in that: The moving block moves to the area with a casting section width of 0.25L and 0.75L. Or / and, n takes the value of 5. When the steel grade is low-carbon steel, the 1st - 3rd rapping devices are put into use. Among them, the rapping amplitude of the 1st rapping device is 1.7 mm - 2.3 mm, and the rapping frequency is 77 Hz - 83 Hz; the rapping amplitude of the 2nd rapping device is 2.7 mm - 3.3 mm, and the rapping frequency is 57 Hz - 63 Hz; the rapping amplitude of the 3rd rapping device is 3.7 mm - 4.3 mm, and the rapping frequency is 37 Hz - 43 Hz. When the steel grade is medium-carbon steel, the 1st - 4th rapping devices are put into use. Among them, the rapping amplitude of the 1st rapping device is 1.7 mm - 2.3 mm, and the rapping frequency is 57 Hz - 63 Hz; the rapping amplitude of the 2nd rapping device is 2.7 mm - 3.3 mm, and the rapping frequency is 37 Hz - 43 Hz; the rapping amplitude of the 3rd rapping device is 2.7 mm - 3.3 mm, and the rapping frequency is 17 Hz - 23 Hz; the rapping amplitude of the 4th rapping device is 3.7 mm - 4.3 mm, and the rapping frequency is 7 Hz - 13 Hz. When the steel grade is high-carbon steel or other steel grades, the 1st - 5th rapping devices are put into use. Among them, the rapping amplitude of the 1st rapping device is 1.2 mm - 1.8 mm, and the rapping frequency is 47 Hz - 53 Hz; the rapping amplitude of the 2nd rapping device is 1.7 mm - 2.3 mm, and the rapping frequency is 40 Hz; the rapping amplitude of the 3rd rapping device is 2.2 mm - 2.8 mm, and the rapping frequency is 27 Hz - 33 Hz; the rapping amplitude of the 4th rapping device is 2.7 mm - 3.3 mm, and the rapping frequency is 17 Hz - 23 Hz; the rapping amplitude of the 5th rapping device is 2.7 mm - 3.3 mm, and the rapping frequency is 7 Hz - 13 Hz.

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