Square rectangular cross-section cast iron continuous casting mold and manufacturing method of water cooling plate thereof

Abstract

This invention discloses a rectangular cross-section cast iron continuous casting crystallizer, comprising a crystallizer graphite sleeve, a crystallizer water-cooling sleeve, a small transition plate, and a large transition plate sequentially fitted onto the outer wall of the crystallizer graphite sleeve, which are connected in sequence. A crystallizer end pressure plate is also provided at one end of the crystallizer graphite sleeve, connected to one end of the crystallizer water-cooling sleeve. Through holes with the same cross-sectional dimensions as the outer perimeter of the crystallizer graphite sleeve are opened at the center of the small transition plate, the large transition plate, and the end pressure plate. The water-cooling plate in this crystallizer, through optimized flow channel layout, solves the problems of uneven cooling at the corners of rectangular cast billets and the problems of leakage, water cross-contamination, deformation, scaling, and insufficient heat exchange inherent in traditional water-cooling plates, achieving uniform cooling, reducing the risk of local overheating and cracking, and ultimately improving the forming quality of the cast billet. A method for manufacturing the rectangular cross-section cast iron continuous casting crystallizer water-cooling plate is also disclosed.

Description

Technical Field

[0001] This invention belongs to the field of horizontal continuous casting technology for cast iron profiles, specifically relating to a rectangular cross-section cast iron continuous casting crystallizer, and also relating to a method for manufacturing a rectangular cross-section cast iron continuous casting crystallizer with a water-cooled plate. Background Technology

[0002] Horizontal Continuous Casting (HCC), as a highly efficient near-net-shape forming technology for metallic materials, has been widely applied in the industrial production of various sections of cast iron profiles, including gray cast iron, ductile iron, and alloy cast iron, due to its advantages such as short process flow, high production efficiency, and high degree of automation. In this process, the crystallizer water-cooled plate is considered the "heart" of continuous casting production. Its function is to forcibly cool the high-temperature molten iron flowing from the holding furnace into the crystallizer, allowing it to solidify its outer shell and build sufficient strength to resist the mechanical tension generated by the "pull-stop-pull" pulse motion of the traction machine in a very short time. Therefore, the structural reliability, cooling uniformity, and manufacturing process maturity of the crystallizer water-cooled plate directly determine the continuity of continuous casting production, the yield of cast iron profiles, and the service life of the equipment.

[0003] However, as industry demands increasingly more complex cross-sections and higher internal quality requirements for cast iron profiles, existing crystallizer manufacturing technologies are gradually revealing some bottlenecks. Currently, two crystallizer methods are commonly used to produce cast iron profiles with rectangular or square cross-sections: (1) For cast iron profiles with larger cross sections, four horizontal continuous casting crystallizer water-cooling plates are usually connected by bolts and a graphite sleeve is tightly clamped in place. The cross-sectional shape of the inner hole of the graphite sleeve is the cross-sectional shape of the rectangular cast iron profile. Each crystallizer water-cooling plate generally adopts the traditional manufacturing mode of "machined inner sleeve (plate) + welded outer sleeve (plate) tube + annealing heat treatment", and then is precision machined to make the crystallizer water-cooling plate. Finally, the four crystallizer water-cooling plates are assembled together by bolts, and the graphite sleeve is clamped in the cavity formed by the four crystallizer water-cooling plates, ensuring that the contact surface between each crystallizer water-cooling plate and the graphite sleeve is tightly fitted to ensure heat transfer. It can be seen that this traditional production mode of "machined parts + welding + heat treatment + precision machining" has a long production cycle, high cost, low efficiency, and complicated replacement and assembly process.

[0004] (2) For cast iron profiles with relatively small cross-sections, a traditional circular cross-section crystallizer is typically used. The process involves "machining parts + welding + annealing + precision machining." A water-cooled steel sleeve with a circular inner diameter is then placed on a press, and a graphite sleeve with a circular outer diameter is pressed into the inner hole of the crystallizer's water-cooled sleeve to ensure a tight fit and efficient heat transfer. Finally, the inner hole of the graphite sleeve is machined into a corresponding circular, rectangular, or other irregular cross-section using a lathe or a dedicated wire saw to meet the production needs of cast iron profiles with different cross-sectional shapes. This method is currently the most widely used, but it is not only costly and inefficient, but also has significant limitations, including the inability to achieve combination and restrictions on the inner hole size.

[0005] Therefore, it is evident that the manufacturing cycle of water-cooled plates for crystallizers is long, and the size and assembly of crystallizers cannot meet the increasing diversity of cast iron profile cross-sectional dimensions. While the above method is acceptable for circular or smaller rectangular profiles, it is difficult to use circular crystallizers for larger rectangular cast iron profiles. Furthermore, when using circular crystallizers to produce rectangular cast iron profiles, the faster cooling rate at the corners easily leads to white cast iron and cracks at the corners, and also results in higher hardness at the corners. Therefore, based on practical production considerations, the optimal crystallizer choice for producing rectangular cast iron profiles is a rectangular crystallizer composed of four separate water-cooled plates, rather than directly using a circular crystallizer. A search reveals several typical structural forms in existing technologies, but these are accompanied by corresponding process defects. The first type is the "deep-hole drilling" structure. For example, patent CN101036936A (publication date 2007-09-19), "Horizontal Continuous Casting Tubular Crystallizer for Copper Slabs," discloses a technical solution of directly drilling multiple sets of parallel longitudinal water holes inside the copper slab as cooling channels. Although this structure has acceptable overall strength, it is limited by the "straight in, straight out" characteristic of the drilling process, meaning the flow channel can only be a straight line, making it impossible to achieve a smooth bending transition at the corners of the rectangular crystallizer, resulting in a large cooling blind zone. Furthermore, to prevent drill-through, an extremely thick safety wall thickness must be reserved, severely hindering the rapid dissipation of heat. In addition, combined with current conventional technology, this structure is not suitable for horizontal continuous casting processes of cast iron.

[0006] The second type is the "milling groove + sleeve welding" structure. For example, the applicant's previous patents CN104325098A (publication date: 2015-02-04) "A double water jacket crystallizer for horizontal continuous casting of cast iron" and CN202461464U (publication date: 2012-10-03) "A new type of horizontal continuous casting crystallizer" are the most widely used structural forms at present. The process usually involves first turning or milling spiral or trapezoidal water channel grooves on the outer wall of the inner sleeve, and then installing the outer sleeve and welding the inlet and outlet water pipes and flanges to form a closed flow channel. However, its manufacturing process is extremely complex, requiring numerous steps such as "rough turning of the inner sleeve → water channel milling → outer sleeve assembly → welding of the sleeve → stress-relief annealing → precision machining of the sealing surface," resulting in a long production cycle. Because a large area needs to be welded between the inner and outer sleeves, the welding heat input easily causes warping and deformation of the components. To ensure a high-precision fit with the graphite sleeve, a long-term high-temperature annealing process is necessary to eliminate welding stress, followed by secondary precision machining to correct the deformation, leading to a long manufacturing cycle and high production costs. Furthermore, this fully enclosed welded structure makes the internal flow channels a closed space that cannot be disassembled and cleaned. During long-term use, calcium and magnesium ions in the cooling water easily deposit in the dead corners of the spiral flow channels, forming scale. Because it cannot be opened for maintenance, the scale layer continuously thickens, causing a sharp decrease in thermal conductivity, which in turn leads to a significant reduction in the cooling efficiency of the crystallizer. This results in abnormally high surface temperatures of the cast billet, insufficient solidification shell growth thickness, or cracking, creating serious production safety hazards.

[0007] The third type is the "split-assembly" structure. Technologies disclosed in patents such as CN201470847U (publication date: 2010-05-19) "A Copper Sleeve for a Horizontal Continuous Casting Crystallizer" attempt to solve the processing difficulties through split-type guide channels or inserts. However, under the high-frequency vibration conditions of a horizontal continuous casting machine, the sealing surfaces of this multi-part spliced ​​structure are extremely prone to fatigue failure. In particular, the inlet and outlet nozzles are usually screwed in or externally welded (e.g., CN2236914Y (publication date: 1996-10-09) "Extra-long Copper Inner Sleeve Crystallizer for a Horizontal Continuous Casting Machine"). Under repeated mechanical thrust, the base of the nozzle often loosens or breaks, leading to cooling water leakage into high-temperature areas, posing a significant safety hazard.

[0008] In summary, existing technologies are mainly limited by the traditional "subtractive manufacturing" mindset of machining + welding, and generally suffer from cumbersome manufacturing processes, limited structural design, and difficulties in operation and maintenance. They also present some common and unresolved practical problems, including: 1. The water-cooled plate of the crystallizer after assembly and welding must be subjected to water pressure test after processing to avoid water leakage. If leakage occurs, welding repair and maintenance are required. 2. Since the water channel is assembled by welding two pieces together, the middle of the water channel is not sealed, which may cause water leakage and affect the cooling capacity. At the same time, due to water leakage in local gaps, scale will usually appear, which will further reduce the cooling capacity of the water-cooled plate. 3. Since the two water channels are only welded together around the perimeter and not in the middle, the rigidity of such rectangular crystallizer water cooling plates (sleeves) is obviously insufficient and they are easily deformed. 4. The water channels of traditional crystallizer water-cooled plates are simply rectangular cross-section water passages. Because the heat is carried away by the heat exchange between the simple channel walls and the flowing cooling water, the heat exchange capacity is limited, restricting the cooling capacity of the crystallizer water-cooled plate. Furthermore, due to localized boiling of the cooling water, scale will form inside the channels, further reducing cooling efficiency.

[0009] 5. The manufacturing cycle of this welding method is generally long, and it is difficult to change the structure and size of the crystallizer, especially for water-cooled plates of crystallizers with square or rectangular cross-sections. Due to the increasing variety of cast iron profile cross-sectional shapes and sizes, the traditional combination method limits the practical application and development cycle of water-cooled plates for crystallizers with different cross-sections. Therefore, there is an urgent need to introduce a new type of crystallizer water-cooled plate that can simplify the manufacturing process, avoid welding and multiple heat treatment processes, achieve integrated rapid forming of the flow channel, and have high structural reliability, as well as a rapid prototyping manufacturing method, in order to solve the systemic problems of complex processes, easy scaling, easy leakage, and long production cycles in the existing technologies. Summary of the Invention

[0010] The first objective of this invention is to provide a rectangular cross-section cast iron continuous casting crystallizer. The water-cooled plate in this crystallizer, through optimized flow channel layout, solves the problems of uneven cooling at the corners of rectangular cast billets and the problems of leakage, water cross-contamination, deformation, scaling and insufficient heat exchange of traditional water-cooled plates. It achieves uniform cooling, reduces the risk of local overheating and cracking, and ultimately improves the forming quality of the cast billet.

[0011] Another objective of this invention is to provide a method for manufacturing water-cooled plates for cast iron continuous casting crystallizers with rectangular cross-sections. By using an integrated rapid prototyping method based on additive manufacturing, the technical challenge of machining complex internal flow channels and internal support structures is solved, significantly simplifying the manufacturing process, reducing production costs, and improving the heat exchange efficiency and structural reliability of the crystallizer.

[0012] The first technical solution adopted in this invention is a rectangular cross-section cast iron continuous casting crystallizer, including a crystallizer graphite sleeve, a crystallizer water-cooling sleeve, a crystallizer small transition plate and a crystallizer large transition plate are sequentially fitted on the outer wall of the crystallizer graphite sleeve, and the crystallizer water-cooling sleeve, the crystallizer small transition plate and the crystallizer large transition plate are sequentially connected; a crystallizer end pressure plate is also provided at one end of the crystallizer graphite sleeve, and the crystallizer end pressure plate is connected to one end of the crystallizer water-cooling sleeve; The crystallizer small transition plate, crystallizer large transition plate, and crystallizer end pressure plate all have through holes with the same cross-sectional dimensions as the outer periphery of the crystallizer graphite sleeve at their center.

[0013] The invention is further characterized in that: The crystallizer water cooling jacket includes four crystallizer water cooling plates. Depending on the installation position, the four crystallizer water cooling plates are divided into two oppositely arranged wide-side crystallizer water cooling plates and two oppositely arranged narrow-side crystallizer water cooling plates. Alternatively, there can be four water cooling plates of the same size. The wide and narrow sides are relative. The two wide-side water-cooling plates and the two narrow-side water-cooling plates of the crystallizer are all connected to the outer wall of the graphite sleeve of the crystallizer by bolts to achieve a tight fit; One end of each of the two wide-side water-cooled plates of the crystallizer and one end of each of the two narrow-side water-cooled plates of the crystallizer are connected to the small transition plate of the crystallizer by bolts. The other ends of the two wide-side water-cooled plates and the two narrow-side water-cooled plates of the crystallizer are all connected to the crystallizer end pressure plate by bolts.

[0014] The crystallizer wide-side water-cooled plate includes a wide-side support plate, wide-side water-cooled plate side ears extending from the edges of both sides of the wide-side support plate, a wide-side upper mounting plate extending from the first edge of the wide-side support plate, and a wide-side lower mounting plate extending from the second edge of the wide-side support plate. The outer surface of the wide-side support plate is provided with several crystallizer wide-side water-cooled plate ribs. The outer surface of the wide-side support plate is also provided with crystallizer wide-side water-cooled plate inlet and outlet water nozzles. The inside of the wide-side support plate is provided with crystallizer wide-side water-cooled plate serpentine water channel. The crystallizer wide-side water-cooled plate inlet water nozzle is connected to the head end of the crystallizer wide-side water-cooled plate serpentine water channel, and the crystallizer wide-side water-cooled plate outlet water nozzle is connected to the tail end of the crystallizer wide-side water-cooled plate serpentine water channel. The crystallizer narrow-edge water-cooled plate includes a narrow-edge support plate, with narrow-edge water-cooled plate side ears extending from the edges of both sides of the narrow-edge support plate, a narrow-edge upper mounting plate extending from the first edge of the narrow-edge support plate, and a narrow-edge lower mounting plate extending from the second edge of the narrow-edge support plate. A plurality of narrow-side water-cooling plate rib plates of the crystallizer are arranged on the outer surface of the narrow-side support plate, and a water inlet nozzle for the narrow-side water-cooling plate of the crystallizer and a water outlet nozzle for the narrow-side water-cooling plate of the crystallizer are also arranged on the outer surface of the narrow-side support plate; a serpentine water channel for the narrow-side water-cooling plate of the crystallizer is arranged inside the narrow-side support plate; the water inlet nozzle for the narrow-side water-cooling plate of the crystallizer is communicated with the head end of the serpentine water channel for the narrow-side water-cooling plate of the crystallizer, and the water outlet nozzle for the narrow-side water-cooling plate of the crystallizer is communicated with the tail end of the serpentine water channel for the narrow-side water-cooling plate of the crystallizer; The wide-side water-cooling plate lugs on both sides of each wide-side support plate are in mutual fitting contact with the narrow-side water-cooling plate lugs on both sides of the adjacent narrow-side support plate, and are connected through a plurality of groups of crystallizer water-cooling plate fixing bolts matched with crystallizer water-cooling plate fixing nuts; two wide-side water-cooling plates of the crystallizer and two narrow-side water-cooling plates of the crystallizer surround the crystallizer graphite sleeve in a square shape, and both the two wide-side support plates and the two narrow-side water-cooling plates of the crystallizer are in close fitting contact with the outer surface of the crystallizer graphite sleeve; The crystallizer end pressure plate is connected with two groups of upper wide-side mounting plates and two groups of upper narrow-side mounting plates through crystallizer end pressure plate fixing bolts; The small transition plate of the crystallizer is connected with two groups of lower wide-side mounting plates and two groups of lower narrow-side mounting plates through crystallizer small transition plate fixing bolts; A plurality of bionic airfoil-type turbulence self-supporting blocks are arranged on the inner surfaces of both the serpentine water channel of the wide-side water-cooling plate of the crystallizer and the serpentine water channel of the narrow-side water-cooling plate of the crystallizer.

[0015] The bionic airfoil-type turbulence self-supporting blocks are continuously arranged along the straight sections and bent sections of the serpentine water channel of the wide-side water-cooling plate of the crystallizer; the chord length c of the bionic airfoil-type turbulence self-supporting block is 3mm to 5mm, the maximum thickness d is 0.8mm to 1.5mm, and the height of the bionic airfoil-type turbulence self-supporting block is equal to the thickness of the cross section of the water channel.

[0016] The serpentine water channel of the wide-side water-cooling plate of the crystallizer has a rectangular flow cross section, the equivalent width A of the serpentine water channel cross section is 10mm to 30mm, the thickness B of the serpentine water channel is 6mm to 10mm, and the thickness D of the partition wall in the middle of the serpentine water channel is 2mm to 4mm.

[0017] The second technical solution adopted by the present invention is a manufacturing method of a water-cooling plate for a square-rectangular section cast iron continuous casting crystallizer, which is specifically as follows: Step 1, designing a three-dimensional model of the crystallizer water-cooling plate according to the cross-sectional size of the square-rectangular cast iron profile and the solidification heat flux density distribution; Step 2, performing SLM additive manufacturing forming by using selective laser melting (Selective Laser Melting, SLM) equipment according to the designed three-dimensional model of the crystallizer water-cooling plate; Step 3, performing powder cleaning treatment on the overall blank after printing, removing unmelted powder in the water channel; then placing the blank in a heat treatment furnace for stress relief annealing treatment; Step 4: Perform precision machining on the mating surface of the crystallizer water-cooling plate and the crystallizer small transition plate to ensure that the flatness meets the sealing requirements, and conduct a high-pressure water sealing test.

[0018] The invention is further characterized in that: In step 2, the process parameters for SLM additive manufacturing are as follows: laser power is controlled between 200W and 400W; scanning speed is controlled between 600mm / s and 1200mm / s; powder layer thickness is set between 30μm and 50μm; and scanning spacing is controlled between 0.08mm and 0.12mm.

[0019] In step 2, the preheating temperature of the substrate and the forming chamber is controlled between 100℃ and 200℃.

[0020] The beneficial effects of this invention are: (1) The present invention integrates the water nozzle and the crystallizer water cooling plate body into one piece through the SLM process, completely eliminating the traditional threaded or welded connection method, reducing the risk of water nozzle loosening and breakage caused by continuous casting machine vibration from the structural source, and greatly improving the safety and sealing reliability of the equipment.

[0021] (2) In view of the problem of uneven cooling and easy cracking at the corners of rectangular cast iron profiles, the present invention utilizes the forming freedom of SLM process to set up serpentine water channels inside the water-cooled plate of the crystallizer, and appropriately densifies the internal biomimetic airfoil turbulence self-supporting blocks in the corner area, so as to make the cooling intensity of the corner of the billet and the flat surface area more coordinated, thereby reducing the local temperature gradient and reducing the risk of defects such as surface cracks of the billet.

[0022] (3) The present invention integrates a biomimetic airfoil-shaped turbulence self-supporting block inside the serpentine waterway. This structure has dual functions in manufacturing and use: during the SLM forming process, it can serve as an internal support for the top wall of the waterway, reducing the risk of horizontal or near-horizontal flow channel collapse and ensuring the forming accuracy of the internal waterway; during the use of the crystallizer, it can serve as a built-in turbulence rib and heat exchange rib, increasing the heat exchange area, disturbing the cooling water boundary layer, and improving the overall structural rigidity of the water-cooled plate.

[0023] (4) The serpentine water channel of the present invention is integrally formed by SLM process, and the adjacent water channel sections are completely separated by solid partitions, which avoids the problems of water leakage and local stagnation that may occur in traditional welded water cooling plates, thereby reducing the risk of local cooling capacity reduction, local overheating and scaling, and improving the effective cooling capacity and working stability of the crystallizer water cooling plate.

[0024] (5) Compared with traditional deep hole drilling, plug sealing, milling and welding manufacturing processes, the present invention can form internal water channels, internal biomimetic airfoil turbulence self-supporting blocks and external water nozzles in one step, reducing complex machining, welding, repair welding, rework and multiple assembly steps, thereby shortening the manufacturing cycle, reducing manufacturing costs and improving product consistency.

[0025] (6) The present invention adopts a modular structure in which the crystallizer water cooling jacket is formed by combining two wide-side water cooling plates and two narrow-side water cooling plates. The four water cooling plates that make up the crystallizer water cooling jacket only need to keep the length consistent. According to the cross-sectional size of the cast iron profile + the wall thickness of the graphite sleeve, two sets of symmetrical water cooling plates can be selected to quickly assemble the crystallizer water cooling jacket with the corresponding square or rectangular cross-section inner hole, thereby shortening the preparation cycle of crystallizers with different specifications of square and rectangular cast iron profiles and improving the specification switching efficiency. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the rectangular cross-section cast iron continuous casting crystallizer of the present invention after assembly. Figure 2 This is a three-dimensional exploded structural diagram of the water-cooled jacket of the rectangular cross-section cast iron continuous casting crystallizer of the present invention. Figure 3 This is a schematic diagram of the overall three-dimensional structure of the water-cooled plate on the wide side of the crystallizer in the rectangular cross-section cast iron continuous casting crystallizer of the present invention. Figure 4 This is a schematic diagram of the overall three-dimensional structure of the narrow-side water-cooled plate of the crystallizer in the rectangular cross-section cast iron continuous casting crystallizer of the present invention. Figure 5 This is a cross-sectional schematic diagram of the water channel of the wide-side water-cooling plate of the crystallizer in the rectangular cross-section cast iron continuous casting crystallizer of the present invention and its internal support structure conforming to the fluid dynamics section. Figure 6 This is a schematic diagram of the top cross-sectional structure of the water-cooled plate on the wide side of the crystallizer in the rectangular cross-section cast iron continuous casting crystallizer of the present invention. Figure 7 This is a schematic diagram of the structure of the biomimetic airfoil-shaped turbulence-disrupting self-supporting block in the rectangular cross-section cast iron continuous casting crystallizer of the present invention. Figure 8 This is a cross-sectional schematic diagram of the water channel of the narrow side water-cooling plate of the crystallizer in the rectangular cross-section cast iron continuous casting crystallizer of the present invention and the supporting structure of the internal structure conforming to the fluid dynamics section. Figure 9 This is a schematic diagram of a horizontal continuous casting production line for cast iron. Figure 10 This is a schematic diagram showing the installation relationship between the holding furnace and the crystallizer of this invention during the production of continuous casting profiles.

[0027] In the diagram, 1. Crystallizer graphite sleeve; 2. Crystallizer large transition plate; 21. Crystallizer large transition plate fixing bolt; 22. Annular threaded hole; 3. Crystallizer small transition plate; 31. Crystallizer small transition plate fixing bolt; 4. Crystallizer end pressure plate; 41. Crystallizer end pressure plate fixing bolt; 5. Crystallizer wide-side water-cooled plate; 51. Crystallizer wide-side water-cooled plate inlet nozzle; 52. Crystallizer wide-side water-cooled plate outlet nozzle; 53. Crystallizer wide-side water-cooled plate serpentine water channel; 54. Wide-side lower mounting plate; 55. Crystallizer water-cooled plate fixing bolt; 56. Crystallizer water-cooled plate fixing nut; 57. Crystallizer wide-side water-cooled plate rib; 58. Wide-side water-cooled plate side lug; 59. Wide-side support plate; 510. Wide-side upper mounting plate; 6. Crystallizer narrow-side water-cooled plate; 61. Crystallizer narrow-side water-cooled plate inlet nozzle; 62. Crystallizer narrow-side water-cooled plate outlet nozzle. 63. Narrow-edge water-cooled plate serpentine channel for crystallizer; 64. Narrow-edge support plate; 65. Upper mounting plate for narrow-edge; 66. Lower mounting plate for narrow-edge; 67. Rib plate for narrow-edge water-cooled plate of crystallizer; 68. Side lug for narrow-edge water-cooled plate; 7. Bionic airfoil-shaped spoiler self-supporting block; 8. Insulating furnace; 9. Square and rectangular cross-section cast iron continuous casting crystallizer; 10. Support roller; 11. Traction machine; 12. Cutting machine; 13. Counter-pressure gantry; 14. Pressure roller; 15. Material receiving cylinder; 16. Crushing machine; 17. Cable exiting machine; 18. Cast iron profile; 19. Solidified shell part; 20. Unsolidified liquid core part. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0029] This invention provides a square or rectangular cross-section cast iron continuous casting crystallizer, such as... Figures 1-8 As shown, the system includes a crystallizer graphite sleeve 1. A crystallizer water-cooling sleeve, a small transition plate 3, and a large transition plate 2 are sequentially fitted onto the outer wall of the crystallizer graphite sleeve 1. These components are connected from top to bottom according to the diagram. In actual production, the crystallizer is placed horizontally. The large transition plate 2 is connected to a holding furnace 8. One end of the crystallizer graphite sleeve 1 extends into the holding furnace 8 and is connected to it via refractory material. A crystallizer end pressure plate 4 is also provided at one end of the crystallizer graphite sleeve 1, and this end pressure plate 4 is connected to one end of the crystallizer water-cooling sleeve. The crystallizer small transition plate 3, the crystallizer large transition plate 2, and the crystallizer end pressure plate 4 all have through holes with the same cross-sectional dimensions as the outer periphery of the crystallizer graphite sleeve 1 at their centers.

[0030] The crystallizer water cooling jacket includes four crystallizer water cooling plates, which are connected and combined by several bolts to form a crystallizer water cooling jacket with a rectangular internal cavity. The four crystallizer water-cooling plates are divided into two oppositely arranged crystallizer wide-side water-cooling plates 5 and two oppositely arranged crystallizer narrow-side water-cooling plates 6, depending on their installation positions. The two wide-side water-cooling plates 5 and the two narrow-side water-cooling plates 6 of the crystallizer are all connected to the outer wall of the graphite sleeve 1 of the crystallizer by bolts to achieve a tight fit; One end of each of the two wide-side water-cooled plates 5 and the two narrow-side water-cooled plates 6 of the crystallizer is connected to the small transition plate 3 of the crystallizer by several bolts. The other ends of the two wide-side water-cooled plates 5 and the two narrow-side water-cooled plates 6 of the crystallizer are connected to the crystallizer end pressure plate 4 by several bolts.

[0031] The crystallizer wide-side water-cooled plate 5 includes a wide-side support plate 59, wide-side water-cooled plate side ears 58 extending from the edges of both sides of the wide-side support plate 59, a wide-side upper mounting plate 510 extending from the first edge of the wide-side support plate 59, and a wide-side lower mounting plate 54 extending from the second edge of the wide-side support plate 59. The outer surface of the wide-side support plate 59 is provided with several crystallizer wide-side water-cooling plate ribs 57. The outer surface of the wide-side support plate 59 is also provided with crystallizer wide-side water-cooling plate inlet nozzles 51 and crystallizer wide-side water-cooling plate outlet nozzles 52. The inside of the wide-side support plate 59 is provided with crystallizer wide-side water-cooling plate serpentine water channel 53. The crystallizer wide-side water-cooling plate inlet nozzle 51 is connected to the head end of the crystallizer wide-side water-cooling plate serpentine water channel 53, and the crystallizer wide-side water-cooling plate outlet nozzle 52 is connected to the tail end of the crystallizer wide-side water-cooling plate serpentine water channel 53. The crystallizer narrow-edge water-cooled plate 6 includes a narrow-edge support plate 64, with narrow-edge water-cooled plate side ears 68 extending from the edges of both sides of the narrow-edge support plate 64, a narrow-edge upper mounting plate 65 extending from the first edge of the narrow-edge support plate 64, and a narrow-edge lower mounting plate 66 extending from the second edge of the narrow-edge support plate 64. The outer surface of the narrow-edge support plate 64 is provided with several crystallizer narrow-edge water-cooled plate ribs 67. The outer surface of the narrow-edge support plate 64 is also provided with crystallizer narrow-edge water-cooled plate inlet nozzles 61 and crystallizer narrow-edge water-cooled plate outlet nozzles 62. The inside of the narrow-edge support plate 64 is provided with crystallizer narrow-edge water-cooled plate serpentine water channel 63. The crystallizer narrow-edge water-cooled plate inlet nozzle 61 is connected to the head end of the crystallizer narrow-edge water-cooled plate serpentine water channel 63, and the crystallizer narrow-edge water-cooled plate outlet nozzle 62 is connected to the tail end of the crystallizer narrow-edge water-cooled plate serpentine water channel 63. The wide water-cooling plate lugs 58 on both sides of each wide supporting plate 59 are attached to the narrow water-cooling plate lugs 68 on both sides of the adjacent narrow supporting plate 64, and connected by several groups of crystallizer water-cooling plate fixing bolts 55 in cooperation with crystallizer water-cooling plate fixing nuts 56; two crystallizer wide water-cooling plates 5 and two crystallizer narrow water-cooling plates 6 surround the crystallizer graphite sleeve 1 in a shape of "square", and the two wide supporting plates 59 and the two crystallizer narrow water-cooling plates 6 are both closely attached to the outer surface of the crystallizer graphite sleeve 1; The crystallizer end pressure plate 4 is connected to two groups of wide upper mounting plates 510 and two groups of narrow upper mounting plates 65 through crystallizer end pressure plate fixing bolts 41; The small transition plate 3 of the crystallizer is connected to two groups of wide lower mounting plates 54 and two groups of narrow lower mounting plates 66 through fixing bolts 31 for the small transition plate of the crystallizer; A plurality of bionic airfoil-shaped flow-disturbing self-supporting blocks 7 are arranged on the inner surfaces of both the serpentine water channel 53 of the crystallizer wide water-cooling plate and the serpentine water channel 63 of the crystallizer narrow water-cooling plate.

[0032] The bionic airfoil-shaped flow-disturbing self-supporting blocks 7 are continuously arranged along the straight section and the bent section of the serpentine water channel 53 of the crystallizer wide water-cooling plate; the chord length c of the bionic airfoil-shaped flow-disturbing self-supporting block 7 is 3 to 5 mm, the maximum thickness d is 0.8 to 1.5 mm, and the height of the block is equal to the thickness of the water channel cross-section.

[0033] An integrally formed serpentine cooling water channel is arranged inside the crystallizer water-cooling plate, and the water channel is continuously curved in the water-cooling plate to cover the corresponding square-rectangular heat dissipation area; addressing the problems existing in the production of square-rectangular section cast iron profiles, the commutation part of the water channel adopts a conformal arc design to fit the contour of the corner of the crystallizer water-cooling plate, which is more conducive to eliminating heat dissipation dead corners; The water inlet end and water outlet end of the serpentine cooling water channel directly extend out of the surface of the crystallizer water-cooling plate, and are provided with a water inlet nozzle and a water outlet nozzle. Meanwhile, taking advantage of additive manufacturing technology, 1 / 2" or 3 / 4" internal threads are directly arranged inside the nozzles, which can be used after only simple trimming in the later stage. The water inlet and outlet nozzles are a part of the structure of the crystallizer water-cooling plate, and are integrally formed with the crystallizer water-cooling plate by additive manufacturing directly. There is no physical joint, no threaded connection and no welding interface between the nozzles and the crystallizer water-cooling plate, forming a fully dense integral structure; A flow-disturbing structure with self-supporting water channel cavities arranged in an array is arranged and filled in the inner cavity of the serpentine cooling water channel, which is preferably a bionic airfoil-shaped support structure, that is, a process support for additive manufacturing whose cross-sectional shape conforms to fluid mechanics and dynamic cross-section. This structure has a streamlined cross-section, which is used to support the overhanging structure during additive manufacturing, and does not need to be removed after additive manufacturing is completed. It can be used as a built-in heat dissipation rib during the use of the crystallizer water-cooling plate to enhance the turbulent heat exchange effect.

[0034] The serpentine channel 53 of the wide-side water-cooled plate of the crystallizer has a rectangular flow cross-section. The equivalent width A of the serpentine channel cross-section is 10mm to 30mm, the thickness B is 6mm to 10mm, and the thickness D of the partition wall in the middle of the serpentine channel is 2mm to 4mm. The equivalent width of the channel cross-section refers to the distance between the inner walls of two opposing channels measured along the surface of the crystallizer water-cooled plate within a cross-section perpendicular to the local water flow direction; the channel thickness refers to the height of the channel along the thickness direction of the crystallizer water-cooled plate; and the thickness of the partition wall in the middle of the channel refers to the minimum thickness of the solid partition wall between two adjacent serpentine channel sections. It can be flexibly designed according to different billet cross-sectional dimensions and cooling requirements to achieve complex curved channel arrangements, thereby improving the heat exchange area and cooling uniformity. Detailed descriptions of each component are as follows: The graphite sleeve 1 of the crystallizer is located in the innermost layer of the crystallizer structure. The shape and size of its inner cavity determine the cross-sectional shape and size of the rectangular cast iron profile to be produced, and it is used to form the initial solidification and forming space of the cast billet. The graphite sleeve 1 of the crystallizer is made of high-purity graphite, and the minimum wall thickness of the graphite sleeve 1 of the crystallizer shall not be less than 20mm.

[0035] Furthermore, the outer contour dimension of the crystallizer graphite sleeve 1 is 1-2 mm larger than the internal cavity dimension of the rectangular crystallizer water-cooling sleeve formed by the four crystallizer water-cooling plates after all bolts are tightened. In other words, the length and width dimensions of the rectangular crystallizer water-cooling sleeve formed by the four bolts are 1-2 mm smaller than the length and width dimensions of the outer contour of the crystallizer graphite sleeve 1. This ensures that during crystallizer assembly, the four crystallizer water-cooling plates can be tightly fitted to the four sides of the corresponding rectangular crystallizer graphite sleeve 1 through bolt tightening. This ensures that during horizontal continuous casting, the heat from the crystallizer graphite sleeve 1 can be rapidly transferred to the corresponding four crystallizer water-cooling plates through heat conduction and convection exchange within the cooling water channels of the four crystallizer water-cooling plates, quickly carrying away the heat and ensuring the effective cooling capacity of the crystallizer.

[0036] The crystallizer graphite sleeve 1 is set in the internal cavity of the combined crystallizer water cooling jacket. The crystallizer graphite sleeve is set with a square or rectangular shape inside, which is used for the initial solidification of the square or rectangular cast iron profile billet to ensure that the surface of the billet is smooth and flat, and at the same time has good thermal conductivity and self-lubricating properties. The large transition plate 2 of the crystallizer is installed on the outer side of the inlet end of the water-cooling jacket of the crystallizer. Its function is to provide a transition connection, which is to install the combined crystallizer onto the holding furnace. A through hole is opened in the center to allow the graphite sleeve to pass through, and bolt holes are provided on the outer periphery for connection with the small transition plate and the water-cooling plate, providing primary support. At the same time, corresponding through holes are provided on it for connection with the holding furnace. It is a key component for the connection and sealing between the crystallizer and the holding furnace, and an important component for assembling all the crystallizer parts into a unified whole.

[0037] The crystallizer large transition plate 2 has several annular threaded holes 22 on its plate body; the crystallizer small transition plate 3 is connected to the crystallizer large transition plate 2 by several crystallizer large transition plate fixing bolts 21; each crystallizer large transition plate fixing bolt 21 passes through an annular threaded hole 22.

[0038] The small transition plate 3 of the crystallizer is set on the outside of the crystallizer inlet end. During installation, the inlet end of the crystallizer water-cooling jacket composed of four crystallizer water-cooling plates is placed on it, and the four crystallizer water-cooling plates are perpendicular to it and in close contact. It is an important connecting component for assembling the four crystallizer water-cooling plates into a complete crystallizer water-cooling jacket.

[0039] The small transition plate 3 of the crystallizer is located between the large transition plate 2 of the crystallizer and the wide-side water-cooled plate 5 and the narrow-side water-cooled plate 6 of the crystallizer. The small transition plate 3 is connected to the large transition plate 2 of the crystallizer via the large transition plate fixing bolt 21, and is also securely connected to the wide-side water-cooled plate 5 and the narrow-side water-cooled plate 6 of the crystallizer via the small transition plate fixing bolt 31. The main function of the small transition plate 3 is to ensure that the four crystallizer water-cooled plates are combined into a complete crystallizer water-cooling jacket.

[0040] The two sides of the small transition plate 3 of the crystallizer are fastened to the large transition plate and the water-cooled plate of the crystallizer by bolts. The contact surface is required to be flat and without bending, so as to maintain a tight fit under high temperature operation conditions, so as to eliminate the assembly gap of the rectangular plane and ensure that the heat conduction path from the inside of the crystallizer to the water-cooled plate of the crystallizer is efficient and continuous. The crystallizer end pressure plate 4 is located on the outside of the outlet end of the crystallizer water cooling jacket, specifically installed on the top of the four crystallizer water cooling plates. The overall clamping and positioning are achieved by the crystallizer end pressure plate fixing bolts 41. It is mainly used to prevent the axial sliding or movement of the crystallizer graphite sleeve 1 during the continuous casting production process.

[0041] The wide-side water-cooling plate 5 and the narrow-side water-cooling plate 6 of the crystallizer are the core components of this invention. See [link / reference]. Figure 1 and Figure 2 This crystallizer has four enclosed water-cooling plates, corresponding to the front, back, left, and right positions of the rectangular cross-section. Based on the difference in length between the long and short sides of the rectangular cast iron profile, the crystallizer water-cooling plates come in two specifications: wide-side water-cooling plates 5: two plates in total, installed at the long side positions (front and back) of the rectangular cross-section; and narrow-side water-cooling plates 6: two plates in total, installed at the short side positions (left and right) of the rectangular cross-section. If the widths of the wide-side water-cooling plates 5 and narrow-side water-cooling plates 6 are the same, the four plates combined form a square cross-section crystallizer; otherwise, if their dimensions differ, the combined plate forms a rectangular cross-section crystallizer.

[0042] It should be noted that the internal structural logic, flow channel design, and manufacturing process of the narrow-edge water-cooled plate 6 and the wide-edge water-cooled plate 5 of the crystallizer are completely identical. The only difference lies in the plate width and the number of reciprocating cycles of the internal serpentine water channels. For simplicity, this embodiment uses the wide-edge water-cooled plate 5 of the crystallizer as an example (e.g., Figure 3 , Figure 4 (as shown) will be described in detail, and this description also applies to the narrow-edge water-cooled plate 6 of the crystallizer.

[0043] like Figure 3 As shown, the wide-edge water-cooled plate 5 of the crystallizer is a solid component integrally formed using laser selective melting (SLM) technology. From an external structural perspective, the inlet water nozzle 51 and outlet water nozzle 52 of the wide-edge water-cooled plate extend directly from and are integrally formed on its surface. The nozzles and the crystallizer water-cooled plate are integrally 3D printed, with no weld seams or threaded connection interfaces between them, completely eliminating the potential for loosening and leakage of traditional separate nozzles under continuous casting vibration environments.

[0044] like Figure 4 As shown, taking the wide-edge water-cooled plate 5 of the crystallizer as an example, it has an integrally formed closed serpentine water channel 53. The two ends of this water channel are connected to the water inlet 51 and water outlet 52 of the wide-edge water-cooled plate, respectively. To maximize the heat exchange area within the limited plate space, the serpentine water channel 53 has an approximately rectangular flow cross-section. The equivalent width A of the serpentine water channel cross-section is 10mm to 30mm, the thickness B is 6mm to 10mm, and the thickness D of the partition wall in the middle of the serpentine water channel is 2mm to 4mm. The water channel bends in multiple directions within the plate surface to cover the corresponding rectangular heat dissipation area.

[0045] like Figure 4 As shown, within the internal cavity of the serpentine water channel 53 of the wide-side water-cooling plate of the crystallizer, biomimetic airfoil-shaped self-supporting blocks 7, arranged in an array along the water flow direction, are integrally formed using additive manufacturing. Their blunt leading edges face the direction of incoming cooling water, their sharp trailing edges face the direction of outgoing cooling water, and their chord direction is basically consistent with the local water flow direction. The chord length c of the biomimetic airfoil-shaped self-supporting blocks 7 is 3mm to 5mm, the maximum thickness d is 0.8mm to 1.5mm, and their height is equal to the thickness of the water channel cross-section. This streamlined design has significant innovative functions and effects. (1) Process support: In the SLM manufacturing process, the airfoil-shaped solid acts as an effective suspension support for the top wall of the flow channel, which can effectively prevent collapse during 3D printing; (2) Fluid optimization: The streamlined airfoil shape significantly reduces the flow resistance of cooling water and eliminates the vortex area behind the structure, thereby effectively preventing the deposition of scale in the low flow velocity area; (3) Enhanced heat transfer: The airfoil shape supports the surface, which increases the heat transfer area. The arrayed airfoil structure can divide the fluid and induce ordered microturbulence, destroying the laminar boundary layer and greatly improving the heat transfer efficiency without significantly increasing the pumping power consumption. (4) Enhanced rigidity: The wing-shaped support is distributed in the water channel, which is like a reinforcing rib to improve the overall rigidity of the crystallizer water cooling plate. This prevents the crystallizer water cooling plate from deforming or from deforming when the four pieces are assembled due to the tightening of the bolts. It also makes it easier for the crystallizer water cooling plate and the outer surface of the crystallizer graphite sleeve to fit together more tightly, which is more conducive to uniform heat transfer.

[0046] The biomimetic airfoil-shaped self-supporting baffles 7 are continuously arranged along the straight and curved sections of the serpentine water channel 53 on the wide side of the crystallizer water-cooling plate. In each straight water channel section, multiple biomimetic airfoil-shaped self-supporting baffles 7 are arranged at intervals along the water flow direction; in the water channel width direction, single, double, or multiple rows can be set, and a staggered arrangement is preferred.

[0047] Four crystallizer water-cooled plates (i.e., two wide-side water-cooled plates 5 and two narrow-side water-cooled plates 6) are arranged in a "U" shape around the crystallizer graphite sleeve 1. In terms of spatial arrangement, the two wide-side water-cooled plates 5 are positioned opposite each other, and the two narrow-side water-cooled plates 6 are positioned opposite each other, with the wide-side and narrow-side water-cooled plates 5 and 6 alternately spliced. Structurally, each crystallizer water-cooled plate (channel) has outwardly extending wide-side water-cooled plate side ears 58 integrally formed on both sides. During assembly, the four crystallizer water-cooled plates are placed on the crystallizer small transition plate 3, and the crystallizer graphite sleeve 1 is placed at the center of the four crystallizer water-cooled plates. Then, the side ears of the wide-side water-cooled plates 5 and the adjacent narrow-side water-cooled plates 6 are aligned, and the mounting holes on the side ears are aligned. The plates are then symmetrically rotated using the crystallizer water-cooled plate fixing bolts 55 and nuts 56. Tightening. The crystallizer graphite sleeve 1 is tightly clamped and embedded into the rectangular cavity formed by the four crystallizer water-cooling plates through the tightening force of the bolts. This process ensures a tight fit between the outer wall of the crystallizer graphite sleeve and the wall of the crystallizer water-cooling plates, guaranteeing efficient heat exchange. During this process, the outlet end of the graphite sleeve is ensured to be flush with the outlet end of the crystallizer water-cooling sleeve formed by the four water-cooling plates. Finally, the entire assembly is flipped over, and the small transition plate 3 of the crystallizer is sequentially connected and fixed to the four crystallizer water-cooling plates using the small transition plate fixing bolts 31. Simultaneously, to prevent relative sliding or axial movement between the crystallizer graphite sleeve and the crystallizer water-cooling plates during production, a crystallizer end pressure plate 4 is installed at the outlet end of the crystallizer graphite sleeve 1, and the entire assembly is pressed and limited by the crystallizer end pressure plate fixing bolts 41. This prevents the graphite sleeve from sliding or moving.

[0048] To ensure the effective thickness of the solidified shell of the cast billet at the crystallizer outlet and to establish sufficient tensile strength to withstand the pulse-like pulling force of the traction machine, preventing the solidified shell on the surface of the cast billet from cracking, this crystallizer structure adopts a counter-flow cooling layout: that is, the cooling water flow direction of the four crystallizer water-cooled plates (the wide-side water-cooled plate 5 and the narrow-side water-cooled plate 6 of the crystallizer are opposite to the traction direction of the cast iron profile. Taking the wide-side water-cooled plate 5 of the crystallizer as an example, the cooling water flows from the end furthest from the holding furnace (i.e., the billet outlet end) through the wide-side water-cooled plate 5 of the crystallizer. The water enters through the inlet nozzle 51 of the cold plate, flows along the serpentine channel towards the end near the holding furnace (i.e., the molten metal inlet end) and absorbs heat, and finally exits from the end near the holding furnace through the outlet nozzle 52 of the wide-side water-cooled plate of the crystallizer. This flow pattern is also set in the narrow-side water-cooled plate 6 of the crystallizer. This counter-flow arrangement ensures that the cooling water temperature at the crystallizer outlet is the highest, which is more conducive to the rapid thickening and strengthening of the solidified shell of the billet, while avoiding excessive rapid cooling that would cause white iron structure (carbides) to appear during the solidification of the molten iron.

[0049] The crystallizer of this invention mainly consists of four crystallizer water-cooled plates, including four symmetrically arranged water-cooled channel plates attached to the outside of the transition plate assembly. The crystallizer water-cooled plates are integral components formed using laser selective melting technology. Inside the water channels, additive manufacturing supports are provided along the water flow direction, conforming to hydrodynamic and dynamic cross-sections. These supports are not only required by the additive manufacturing process, but also increase the rigidity of the water channels and water-cooled plates, improving the overall rigidity of the water-cooled plates and resisting structural deformation when the components are bolted together. Furthermore, it increases the effective heat dissipation area of ​​the water channels, improving the absolute heat exchange effect of the water-cooled plates, thereby enhancing the overall cooling capacity of the assembled crystallizer, which is crucial for horizontal continuous casting production.

[0050] The entire device is locked and positioned as a whole by the crystallizer end pressure plate, which has high assembly precision and is convenient for maintenance and disassembly. The crystallizer water-cooling plate has excellent free combination, and crystallizers with various cross-sectional sizes can be freely combined using crystallizer water-cooling plates of the same length but different widths.

[0051] The present invention also provides a method for manufacturing the water-cooled plate of the above-mentioned rectangular cross-section cast iron continuous casting crystallizer, specifically including: firstly, model reconstruction, designing a three-dimensional model of the crystallizer water-cooled plate based on the rectangular cast iron profile, integrating the inlet and outlet nozzles with the plate body, and designing a non-solid biomimetic airfoil-shaped self-supporting block inside the serpentine waterway; secondly, SLM additive manufacturing, selecting high-strength, low-cost 3D printing metal powder with suitable thermal conductivity (material such as Q345 carbon steel or 316L stainless steel), using SLM equipment to print the integral blank in one go based on the biomimetic airfoil-shaped self-supporting block; subsequently, using compressed air for high-pressure powder cleaning, removing other necessary supports except for the airfoil-shaped self-supporting block inside the waterway, and performing stress-relief annealing to eliminate residual stress; finally, performing precision machining on the mating surfaces.

[0052] The specific steps are as follows: Step 1: Based on the cross-sectional dimensions and solidification heat flux density distribution of the rectangular cast iron profile, design a three-dimensional model of the crystallizer water-cooling plate; design the inlet and outlet nozzles as part of the plate body extending directly out, and design a non-solid self-supporting turbulence structure inside the serpentine water channel. Step 2: Based on the designed 3D model of the crystallizer water-cooling plate, select a high-strength, low-cost 3D printing metal powder material (Q345 carbon steel or 316L stainless steel) with suitable thermal conductivity, and use a laser selective melting (SLM) device to perform SLM integrated rapid additive manufacturing. The biomimetic airfoil-shaped flow-disrupting self-supporting block serves as the internal forming support for the water channel. The entire crystallizer water-cooling plate blank, including the internal flow channel, internal support and external water nozzle, is formed by one-time SLM printing. Step 3: Clean the printed blank to remove unmelted powder from the water channels; then place it in a heat treatment furnace for stress relief annealing to eliminate residual thermal stress generated during additive manufacturing, prevent deformation of the workpiece during subsequent processing or use, and ensure the stability of its structure and properties. Step 4: Perform precision machining on the mating surface of the crystallizer water cooling plate and the crystallizer small transition plate 3 to ensure that the flatness meets the sealing requirements, and conduct a high-pressure water sealing test.

[0053] The small transition plate 3, the large transition plate 2, and the end pressure plate 4 of the crystallizer are made of ordinary carbon steel. The large transition plate 2 of the crystallizer can be machined from 45 steel or 20 steel plate, and the small transition plate 3 and the end pressure plate 4 of the crystallizer can be machined from Q235 steel plate or 20 steel plate.

[0054] In the aforementioned SLM additive manufacturing steps, to balance the overall density of the crystallizer water-cooled plate and the high-precision forming of the complex internal biomimetic wing structure, the preferred process parameters for SLM additive manufacturing are: laser power controlled between 200W and 400W to avoid insufficient melt pool depth and incomplete fusion defects due to excessively low power, or spherical porosity caused by excessively high power leading to a keyhole mode in the melt pool; scanning speed matched and controlled between 600mm / s and 1200mm / s to prevent spheroidization effect caused by excessively high speed, or excessive heat input and surge in residual stress caused by excessively low speed; powder layer thickness set between 30μm and 50μm, thereby ensuring production efficiency while... Effectively suppressing the step effect ensures high-precision replication of the streamlined curved surface of the micro-chord length airfoil; the scanning spacing is controlled at 0.08mm to 0.12mm to ensure a suitable overlap rate between adjacent molten pools and avoid internal pores during solid area forming; at the same time, the preheating temperature of the substrate and forming chamber is controlled at 100℃ to 200℃, and the temperature gradient during the forming process is effectively reduced by appropriate preheating, reducing the accumulation of thermal stress caused by rapid solidification, and fundamentally preventing warping or cold cracking of the crystallizer water-cooled plate during the forming process.

[0055] All mating surfaces of this crystallizer are precision-machined to ensure flatness and freedom from warping. Cooling water enters the serpentine water channel through the integrally formed water inlet nozzles of each water-cooling plate. The cooling water enters at a pressure of not less than 0.2 MPa, with an inlet temperature of room temperature. After absorbing heat, it is discharged through the integrally formed water outlet nozzles and returns to the circulating system's storage tank. It is particularly important to note that, to prevent calcium and magnesium ions in the cooling water from precipitating and forming scale in the microchannels under high temperature and turbulence, which could lead to channel blockage or reduced heat exchange performance, the cooling circulation system's storage tank of this crystallizer uses softened water, deionized water, or distilled water as the cooling medium. Direct use of untreated hard water or tap water is strictly prohibited.

[0056] During the horizontal continuous casting process, the heat of the molten cast iron is conducted away through the graphite sleeve 1 of the crystallizer, the wide-side water-cooled plate 5 and the narrow-side water-cooled plate 6 of the crystallizer, and the cooling water in their channels. The cooling water absorbs heat during multiple reversals of its flow. In particular, when flowing through the integrated biomimetic airfoil structure inside the serpentine channel, the water flow changes from laminar flow to low-resistance turbulent flow, which not only significantly increases the heat exchange area but also significantly enhances the thermal conductivity through the "fin effect" of the internal support ribs.

[0057] The crystallizer components of this invention are made of different materials: the crystallizer graphite sleeve 1 is preferably made of high-purity graphite; the large transition plate 2 of the crystallizer is machined from 45 steel or 20 steel plate; the small transition plate 3 and the end pressure plate 4 of the crystallizer can be machined from Q235 steel plate or 20 steel plate. The wide-side water-cooling plate 5 and the narrow-side water-cooling plate 6 of the crystallizer can be made from carbon steel such as Q345 or stainless steel such as 316L by SLM printing. After 3D printing is completed, the wide-side water-cooling plate 5 and the narrow-side water-cooling plate 6 of the crystallizer must undergo a water pressure test of more than 0.3MPa and a flow resistance test before they can be assembled and used.

[0058] When used on-site, the crystallizer of this invention is installed at the outlet end of the holding furnace 8 of the horizontal continuous casting production line for cast iron. It is used to receive the high-temperature molten iron flowing out of the holding furnace 8 and to complete the initial solidification and continuous forming of the cast iron profile in the horizontal direction.

[0059] like Figure 9 As shown, the horizontal continuous casting production line for cast iron includes a holding furnace 8, a rectangular cross-section cast iron continuous casting crystallizer 9, a support roller 10, a traction machine 11, a cutting machine 12, a counter-pressure gantry 13, a pressure roller 14, a receiving cylinder 15, a pressing machine 16, and an exit machine 17 arranged sequentially along the traction direction of the cast iron profile 18. The rectangular cross-section cast iron continuous casting crystallizer 9 is installed at the tapping end of the holding furnace 8. After the cast iron profile 18 completes its initial solidification in the crystallizer 9, it is supported by the support roller 10 and intermittently pulled by the traction machine 11 according to a set "pull-stop-pull" pattern, so that the cast iron profile 18, which has formed a solidified shell of a certain thickness, is continuously moved out in the horizontal direction. Subsequently, the cast iron profile 18 passes through the cutting machine 12, the counter-pressure gantry 13, the pressure roller 14, the receiving cylinder 15, the pressing machine 16, and the exit machine 17 in sequence to achieve fixed-length cutting, pressing, and conveying. It can be seen that the rectangular cross-section cast iron continuous casting crystallizer 9 is located between the holding furnace 8 and the subsequent traction, cutting and output equipment, and is a key component that determines the solidification and forming quality of the cast iron profile 18 and the stability of continuous production.

[0060] like Figure 10As shown, a rectangular cross-section cast iron continuous casting crystallizer 9 is installed at the outlet end of the holding furnace 8. The inlet end of the crystallizer graphite sleeve 1 is connected to the molten iron cavity inside the holding furnace 8. The outer side of the crystallizer graphite sleeve 1 is clamped and cooled by the crystallizer water-cooling jacket. Specifically, the rectangular cross-section cast iron continuous casting crystallizer 9 is connected to the holding furnace 8 through the large transition plate 2 of the crystallizer, and the positioning, clamping and limiting of the crystallizer graphite sleeve 1 is completed by the small transition plate 3 of the crystallizer, the end pressure plate 4 of the crystallizer and four crystallizer water-cooling plates. After the high-temperature molten iron enters the inner hole of the crystallizer graphite sleeve 1 from the outlet of the holding furnace 8, it gradually solidifies from the position near the inner wall of the graphite sleeve towards the center under the forced cooling action of the crystallizer water-cooling jacket, forming a solidified shell part 19, and retaining an unsolidified liquid core 20 inside it. With the intermittent traction of the traction machine 11, the solidified shell part 19 and the unsolidified liquid core part 20 move outward along the inner hole of the graphite sleeve 1 of the crystallizer, and gradually form the required rectangular cross-section cast iron profile 18 during the subsequent cooling process.

[0061] In the above process, the outer wall of the crystallizer graphite sleeve 1 is tightly fitted with the inner heat exchange surfaces of the wide-side water-cooled plate 5 and the narrow-side water-cooled plate 6 of the crystallizer. External circulating cooling water enters the serpentine water channel through the integrally formed water inlet nozzles of each water-cooled plate, absorbs the heat transferred by the crystallizer graphite sleeve 1, and is discharged through the water outlet nozzle. Through the above assembly method, it is possible to ensure that the crystallizer graphite sleeve 1 maintains stable positioning under the action of high-temperature molten iron scouring, equipment vibration, and traction reaction force, and to ensure that there is a continuous and efficient heat transfer path between the crystallizer graphite sleeve 1 and the crystallizer water-cooled sleeve, thereby meeting the usage requirements of high temperature, vibration, and continuous cooling conditions in the horizontal continuous casting site.

[0062] Example 1 A crystallizer water-cooling plate is provided for producing gray cast iron profiles with a square cross-section of 160×160mm. After back-calculation based on the cross-sectional dimensional characteristics of the cast iron profile, the minimum outer contour dimension of the crystallizer graphite sleeve 1 should be (200+X)×(200+X)mm, where X=1~2mm. The two wide-side water-cooling plates 5 and the two narrow-side water-cooling plates 6 of the crystallizer are the same size, that is, the four water-cooling plates are the same size. When the graphite sleeve is not embedded, the minimum inner diameter of the combined crystallizer water-cooling sleeve is 201×201mm.

[0063] 316L stainless steel powder was selected, and integrated 3D printing was performed using a laser selective melting (SLM) system. During the 3D modeling stage, the wide-side water-cooled plate 5 of the crystallizer was designed as a single component. The equivalent width A of the serpentine water channel 53 within the wide-side water-cooled plate is 10mm, the thickness B is 6mm, and the thickness D of the intermediate partition wall is 2mm. Inside the water channel, a biomimetic airfoil-shaped self-supporting baffle with a chord length c of 3mm was parametrically designed.

[0064] The manufacturing method of the water-cooled plate for the rectangular cross-section cast iron continuous casting crystallizer is as follows: Step 1: Design a three-dimensional model of the crystallizer water-cooling plate based on the cross-sectional dimensions and solidification heat flux density distribution of the rectangular cast iron profile. Step 2: Based on the designed 3D model of the crystallizer water-cooled plate, SLM additive manufacturing is performed using a laser selective melting (SLM) device. In step 2, the process parameters for SLM additive manufacturing are as follows: laser power is controlled at 200W; scanning speed is matched and controlled at 600mm / s; powder layer thickness is set to 30μm; and scanning spacing is controlled at 0.08mm.

[0065] In step 2, the preheating temperature of the substrate and the forming chamber is controlled at 100°C.

[0066] Step 3: Clean the printed blank to remove unmelted powder from the water channels; then place it in a heat treatment furnace for stress-relieving annealing. Step 4: Perform precision machining on the mating surface of the crystallizer water-cooling plate and the crystallizer small transition plate 3 to ensure that the flatness meets the sealing requirements, and conduct a high-pressure water tightness test.

[0067] The integrated water-cooled plate underwent a 2.0MPa water pressure test and remained under pressure for 30 minutes without leakage. The root of the integrated water nozzle showed no deformation, verifying that the SLM forming structure has extremely high strength and sealing reliability in replacing the traditional welded structure.

[0068] Example 2 A crystallizer water-cooling plate is provided for producing ductile iron profiles with a flat rectangular cross-section of 300mm × 100mm. After back-calculation based on the cross-sectional dimensional characteristics of the cast iron profile, the minimum outer contour dimension of the crystallizer graphite sleeve 1 should be (340+X) × (140+X) mm, where X = 1~2mm. The four crystallizer water-cooling plates consist of two wide-side crystallizer water-cooling plates 5 and two narrow-side crystallizer water-cooling plates 6. When the graphite sleeve is not embedded, the minimum inner diameter of the assembled crystallizer water-cooling sleeve is 341 × 141mm.

[0069] Q345 carbon steel powder was selected, and integrated 3D printing was performed using a laser selective melting (SLM) device. In the 3D modeling stage, the two wide-side water-cooled plates 5 of the crystallizer were designed as a single component, with an equivalent cross-sectional width A of 30mm, a channel thickness B of 10mm, and a middle partition wall thickness D of 4mm. Inside the channel, a biomimetic airfoil-shaped self-supporting block with a chord length c of 5mm was parametrically designed. Similarly, the two narrow-side water-cooled plates 6 of the crystallizer were designed as a single component, with an equivalent cross-sectional width A of 10mm, a channel thickness B of 6mm, and a middle partition wall thickness D of 2mm. Inside the channel, a biomimetic airfoil-shaped self-supporting block with a chord length c of 3mm was parametrically designed.

[0070] The manufacturing method of the water-cooled plate for the rectangular cross-section cast iron continuous casting crystallizer is as follows: Step 1: Design a three-dimensional model of the crystallizer water-cooling plate based on the cross-sectional dimensions and solidification heat flux density distribution of the rectangular cast iron profile. Step 2: Based on the designed 3D model of the crystallizer water-cooled plate, SLM additive manufacturing is performed using a laser selective melting (SLM) device. In step 2, the process parameters for SLM additive manufacturing are as follows: laser power is controlled at 400W; scanning speed is controlled at 1200mm / s; powder layer thickness is set to 50μm; and scanning spacing is controlled at 0.12mm.

[0071] In step 2, the preheating temperature of the substrate and the forming chamber is controlled at 200°C.

[0072] Step 3: Clean the printed blank to remove unmelted powder from the water channels; then place it in a heat treatment furnace for stress-relieving annealing. Step 4: Perform precision machining on the mating surface of the crystallizer water-cooling plate and the crystallizer small transition plate 3 to ensure that the flatness meets the sealing requirements, and conduct a high-pressure water tightness test.

[0073] The integrated water-cooled plate underwent a 2.0MPa water pressure test and remained under pressure for 30 minutes without leakage. The root of the integrated water nozzle showed no deformation, verifying that the SLM forming structure has extremely high strength and sealing reliability in replacing the traditional welded structure.

[0074] Example 3 A crystallizer water-cooling plate is provided for producing ductile iron profiles with a flat rectangular cross-section of 500mm × 150mm. After back-calculation based on the cross-sectional dimensional characteristics of the cast iron profile, the minimum outer contour dimension of the crystallizer graphite sleeve 1 should be (540+X) × (190+X) mm, where X = 1~2mm. The four crystallizer water-cooling plates consist of two wide-side crystallizer water-cooling plates 5 and two narrow-side crystallizer water-cooling plates 6. When the graphite sleeve is not embedded, the minimum inner diameter of the assembled crystallizer water-cooling sleeve is 541 × 191mm.

[0075] Q345 carbon steel powder was selected, and integrated 3D printing was performed using a laser selective melting (SLM) device. In the 3D modeling stage, the two wide-side water-cooled plates 5 of the crystallizer were designed as a single component, with an equivalent cross-sectional width A of 30mm, a channel thickness B of 8mm, and a middle partition wall thickness D of 4mm. Inside the channel, a biomimetic airfoil-shaped self-supporting block with a chord length c of 5mm was parametrically designed. Similarly, the two narrow-side water-cooled plates 6 of the crystallizer were designed as a single component, with an equivalent cross-sectional width A of 16mm, a channel thickness B of 8mm, and a middle partition wall thickness D of 3mm. Inside the channel, a biomimetic airfoil-shaped self-supporting block with a chord length c of 3.5mm was parametrically designed.

[0076] The manufacturing method of the water-cooled plate for the rectangular cross-section cast iron continuous casting crystallizer is as follows: Step 1: Design a three-dimensional model of the crystallizer water-cooling plate based on the cross-sectional dimensions and solidification heat flux density distribution of the rectangular cast iron profile. Step 2: Based on the designed 3D model of the crystallizer water-cooled plate, SLM additive manufacturing is performed using a laser selective melting (SLM) device. In step 2, the process parameters for SLM additive manufacturing are as follows: laser power is controlled at 300W; scanning speed is matched and controlled at 1000mm / s; powder layer thickness is set to 40μm; and scanning spacing is controlled at 0.10mm.

[0077] In step 2, the preheating temperature of the substrate and the forming chamber is controlled at 150°C.

[0078] Step 3: Clean the printed blank to remove unmelted powder from the water channels; then place it in a heat treatment furnace for stress-relieving annealing. Step 4: Perform precision machining on the mating surface of the crystallizer water-cooling plate and the crystallizer small transition plate 3 to ensure that the flatness meets the sealing requirements, and conduct a high-pressure water tightness test.

[0079] The integrated water-cooled plate underwent a 2.0MPa water pressure test and remained under pressure for 30 minutes without leakage. The root of the integrated water nozzle showed no deformation, verifying that the SLM forming structure has extremely high strength and sealing reliability in replacing the traditional welded structure.

[0080] Example 4 A crystallizer water-cooling plate is provided for producing ductile iron profiles with a flat rectangular cross-section of 380mm × 250mm. After back-calculation based on the cross-sectional dimensional characteristics of the cast iron profile, the minimum outer contour dimension of the crystallizer graphite sleeve 1 should be (420+X) × (290+X) mm, where X = 1~2mm. The four water-cooling plates consist of two wide-side crystallizer water-cooling plates 5 and two narrow-side crystallizer water-cooling plates 6. When the graphite sleeve is not embedded, the minimum inner diameter of the combined crystallizer water-cooling sleeve is 421 × 291mm.

[0081] Q345 carbon steel powder was selected, and integrated 3D printing was performed using a laser selective melting (SLM) device. In the 3D modeling stage, the two wide-side water-cooled plates 5 of the crystallizer were designed as a single component, with an equivalent cross-sectional width A of 30mm, a channel thickness B of 8mm, and a middle partition wall thickness D of 4mm within the internal serpentine channel 53. Inside the channel, a biomimetic airfoil-shaped self-supporting block with a chord length c of 4mm was parametrically designed. Similarly, the two narrow-side water-cooled plates 6 of the crystallizer were designed as a single component, with an equivalent cross-sectional width A of 18mm, a channel thickness B of 8mm, and a middle partition wall thickness D of 3mm within the internal serpentine channel. Inside the channel, a biomimetic airfoil-shaped self-supporting block with a chord length c of 4mm was parametrically designed.

[0082] The manufacturing method of the water-cooled plate for the rectangular cross-section cast iron continuous casting crystallizer is as follows: Step 1: Design a three-dimensional model of the crystallizer water-cooling plate based on the cross-sectional dimensions and solidification heat flux density distribution of the rectangular cast iron profile. Step 2: Based on the designed 3D model of the crystallizer water-cooled plate, SLM additive manufacturing is performed using a laser selective melting (SLM) device. In step 2, the process parameters for SLM additive manufacturing are as follows: laser power is controlled at 200W; scanning speed is controlled at 1200mm / s; powder layer thickness is set to 35μm; and scanning spacing is controlled at 0.09mm.

[0083] In step 2, the preheating temperature of the substrate and the forming chamber is controlled at 100°C.

[0084] Step 3: Clean the printed blank to remove unmelted powder from the water channels; then place it in a heat treatment furnace for stress-relieving annealing. Step 4: Perform precision machining on the mating surface of the crystallizer water-cooling plate and the crystallizer small transition plate 3 to ensure that the flatness meets the sealing requirements, and conduct a high-pressure water tightness test.

[0085] The integrated water-cooled plate underwent a 2.0MPa water pressure test and remained under pressure for 30 minutes without leakage. The root of the integrated water nozzle showed no deformation, verifying that the SLM forming structure has extremely high strength and sealing reliability in replacing the traditional welded structure.

[0086] Example 5 A crystallizer water-cooling plate is provided for producing ductile iron profiles with a square cross-section of 220mm × 220mm. Based on the cross-sectional dimensions of the cast iron profile, the minimum outer contour dimension of the crystallizer graphite sleeve 1 should be (260 + A) × (260 + A) mm, where X = 1~2mm. The wide-side water-cooling plate 5 and the narrow-side water-cooling plate 6 of the crystallizer have the same dimensions, meaning all four water-cooling plates are identical. Without the graphite sleeve embedded, the minimum inner diameter of the assembled crystallizer water-cooling sleeve is 261 × 261 mm.

[0087] 316L stainless steel powder was selected, and integrated 3D printing was performed using a laser selective melting (SLM) system. During the 3D modeling stage, both the wide-side water-cooled plate 5 and the narrow-side water-cooled plate 6 of the crystallizer were designed as integral components. The equivalent width A of the internal serpentine channel is 18mm, the thickness B is 8mm, and the thickness D of the intermediate partition wall is 3mm. Inside the channel, a biomimetic airfoil-shaped self-supporting baffle with a chord length c of 4mm was parametrically designed.

[0088] The manufacturing method of the water-cooled plate for the rectangular cross-section cast iron continuous casting crystallizer is as follows: Step 1: Design a three-dimensional model of the crystallizer water-cooling plate based on the cross-sectional dimensions and solidification heat flux density distribution of the rectangular cast iron profile. Step 2: Based on the designed 3D model of the crystallizer water-cooled plate, SLM additive manufacturing is performed using a laser selective melting (SLM) device. In step 2, the process parameters for SLM additive manufacturing are as follows: laser power is controlled at 260W; scanning speed is matched and controlled at 600mm / s; powder layer thickness is set to 40μm; and scanning spacing is controlled at 0.08mm.

[0089] In step 2, the preheating temperature of the substrate and the forming chamber is controlled at 160°C.

[0090] Step 3: Clean the printed blank to remove unmelted powder from the water channels; then place it in a heat treatment furnace for stress-relieving annealing. Step 4: Perform precision machining on the mating surface of the crystallizer water-cooling plate and the crystallizer small transition plate 3 to ensure that the flatness meets the sealing requirements, and conduct a high-pressure water tightness test.

[0091] The integrated water-cooled plate underwent a 2.0MPa water pressure test and remained under pressure for 30 minutes without leakage. The root of the integrated water nozzle showed no deformation, verifying that the SLM forming structure has high strength and sealing reliability in replacing the traditional welded structure.

[0092] Example 6 A crystallizer water-cooling plate is provided for producing gray cast iron profiles with a flat rectangular cross-section of 450mm × 200mm. After back-calculation based on the cross-sectional dimensional characteristics of the cast iron profile, the minimum outer contour dimension of the crystallizer graphite sleeve 1 should be (490 + A) × (240 + A) mm, where X = 1~2mm. The four crystallizer water-cooling plates consist of two wide-side crystallizer water-cooling plates 5 and two narrow-side crystallizer water-cooling plates 6. When the graphite sleeve is not embedded, the minimum inner diameter of the assembled crystallizer water-cooling sleeve is 491 × 241mm.

[0093] Q345 carbon steel powder was selected, and integrated 3D printing was performed using a laser selective melting (SLM) device. In the 3D modeling stage, the two wide-side water-cooled plates 5 of the crystallizer were designed as a single component, with an equivalent cross-sectional width A of 28mm, a channel thickness B of 9mm, and a middle partition wall thickness D of 4mm within the internal serpentine channel 53. Inside the channel, a biomimetic airfoil-shaped self-supporting block with a chord length c of 5mm was parametrically designed. Similarly, the two narrow-side water-cooled plates 6 of the crystallizer were designed as a single component, with an equivalent cross-sectional width A of 14mm, a channel thickness B of 7mm, and a middle partition wall thickness D of 3mm within the internal serpentine channel 63. Inside the channel, a biomimetic airfoil-shaped self-supporting block with a chord length c of 3.5mm was parametrically designed.

[0094] The manufacturing method of the water-cooled plate for the rectangular cross-section cast iron continuous casting crystallizer is as follows: Step 1: Design a three-dimensional model of the crystallizer water-cooling plate based on the cross-sectional dimensions and solidification heat flux density distribution of the rectangular cast iron profile. Step 2: Based on the designed 3D model of the crystallizer water-cooled plate, SLM additive manufacturing is performed using a laser selective melting (SLM) device. In step 2, the process parameters for SLM additive manufacturing are as follows: laser power is controlled at 300W; scanning speed is matched and controlled at 900mm / s; powder layer thickness is set to 30μm; and scanning spacing is controlled at 0.08mm.

[0095] In step 2, the preheating temperature of the substrate and the forming chamber is controlled at 180°C.

[0096] Step 3: Clean the printed blank to remove unmelted powder from the water channels; then place it in a heat treatment furnace for stress-relieving annealing. Step 4: Perform precision machining on the mating surface of the crystallizer water-cooling plate and the crystallizer small transition plate 3 to ensure that the flatness meets the sealing requirements, and conduct a high-pressure water tightness test.

[0097] The integrated water-cooled plate underwent a 2.0MPa water pressure test and remained under pressure for 30 minutes without leakage. The root of the integrated water nozzle showed no deformation, verifying that the SLM forming structure has high strength and sealing reliability in replacing the traditional welded structure.

Claims

1. A rectangular cross-section cast iron continuous casting crystallizer, characterized in that, It includes a crystallizer graphite sleeve (1), and a crystallizer water cooling sleeve, a crystallizer small transition plate (3) and a crystallizer large transition plate (2) are sequentially fitted on the outer wall of the crystallizer graphite sleeve (1). The crystallizer water cooling sleeve, the crystallizer small transition plate (3) and the crystallizer large transition plate (2) are connected in sequence. A crystallizer end pressure plate (4) is also provided at one end of the crystallizer graphite sleeve (1), and the crystallizer end pressure plate (4) is connected to one end of the crystallizer water cooling sleeve. The crystallizer small transition plate (3), crystallizer large transition plate (2) and crystallizer end pressure plate (4) all have through holes with the same cross-sectional dimensions as the outer periphery of the crystallizer graphite sleeve (1) at their center.

2. The rectangular cross-section cast iron continuous casting crystallizer according to claim 1, characterized in that, The crystallizer water cooling jacket includes four crystallizer water cooling plates, which are divided into two oppositely arranged wide-side crystallizer water cooling plates (5) and two oppositely arranged narrow-side crystallizer water cooling plates (6) according to their installation positions. The two wide-side water-cooled plates (5) and the two narrow-side water-cooled plates (6) of the crystallizer are tightly fitted to the outer wall of the graphite sleeve (1) of the crystallizer; One end of each of the two wide-side water-cooled plates (5) and the two narrow-side water-cooled plates (6) of the crystallizer is connected to the small transition plate (3) of the crystallizer by bolts; The other ends of the two wide-side water-cooled plates (5) and the two narrow-side water-cooled plates (6) of the crystallizer are connected to the crystallizer end pressure plate (4) by bolts.

3. The rectangular cross-section cast iron continuous casting crystallizer according to claim 2, characterized in that, The crystallizer wide-side water-cooled plate (5) includes a wide-side support plate (59), wide-side water-cooled plate side ears (58) are respectively extended at the edges of both sides of the wide-side support plate (59), a wide-side upper mounting plate (510) is extended at the first edge of the wide-side support plate (59), and a wide-side lower mounting plate (54) is extended at the second edge of the wide-side support plate (59). The outer surface of the wide-side support plate (59) is provided with a plurality of crystallizer wide-side water-cooled plate ribs (57), and the outer surface of the wide-side support plate (59) is also provided with crystallizer wide-side water-cooled plate inlet nozzle (51) and crystallizer wide-side water-cooled plate outlet nozzle (52); the inside of the wide-side support plate (59) is provided with crystallizer wide-side water-cooled plate serpentine water channel (53); the crystallizer wide-side water-cooled plate inlet nozzle (51) is connected to the head end of the crystallizer wide-side water-cooled plate serpentine water channel (53), and the crystallizer wide-side water-cooled plate outlet nozzle (52) is connected to the tail end of the crystallizer wide-side water-cooled plate serpentine water channel (53); The crystallizer narrow-edge water-cooled plate (6) includes a narrow-edge support plate (64), and narrow-edge water-cooled plate side ears (68) are respectively extended at the edges of both sides of the narrow-edge support plate (64). A narrow-edge upper mounting plate (65) is extended at the first edge of the narrow-edge support plate (64), and a narrow-edge lower mounting plate (66) is extended at the second edge of the narrow-edge support plate (64). The outer surface of the narrow-side support plate (64) is provided with a plurality of rib plates (67) of the narrow-side water-cooled plate of the crystallizer, and the outer surface of the narrow-side support plate (64) is further provided with a water inlet nozzle (61) of the narrow-side water-cooled plate of the crystallizer and a water outlet nozzle (62) of the narrow-side water-cooled plate of the crystallizer; a serpentine water channel (63) of the narrow-side water-cooled plate of the crystallizer is arranged inside the narrow-side support plate (64); the water inlet nozzle (61) of the narrow-side water-cooled plate of the crystallizer communicates with the head end of the serpentine water channel (63) of the narrow-side water-cooled plate of the crystallizer, and the water outlet nozzle (62) of the narrow-side water-cooled plate of the crystallizer communicates with the tail end of the serpentine water channel (63) of the narrow-side water-cooled plate of the crystallizer; The wide-side water-cooled plate lugs (58) on both sides of each wide-side support plate (59) and the narrow-side water-cooled plate lugs (68) on both sides of the adjacent narrow-side support plate (64) are attached to each other and connected by a plurality of sets of crystallizer water-cooled plate fixing bolts (55) cooperating with crystallizer water-cooled plate fixing nuts (56); two wide-side water-cooled plates (5) and two narrow-side water-cooled plates (6) of the crystallizer surround the graphite sleeve (1) of the crystallizer in a shape of a "square", and both the two wide-side support plates (59) and the two narrow-side water-cooled plates (6) of the crystallizer are closely attached to the outer surface of the graphite sleeve (1) of the crystallizer; The end pressure plate (4) of the crystallizer is connected to two sets of upper wide-side mounting plates (510) and two sets of upper narrow-side mounting plates (65) via end pressure plate fixing bolts (41) of the crystallizer; The small transition plate (3) of the crystallizer is connected to two sets of lower wide-side mounting plates (54) and two sets of lower narrow-side mounting plates (66) via small transition plate fixing bolts (31) of the crystallizer; A plurality of bionic airfoil-type flow-disturbing self-supporting blocks (7) are arranged on the inner surfaces of both the serpentine water channel (53) of the wide-side water-cooled plate of the crystallizer and the serpentine water channel (63) of the narrow-side water-cooled plate of the crystallizer.

4. The rectangular cross-section cast iron continuous casting crystallizer according to claim 3, characterized in that, The bionic airfoil-type flow-disturbing self-supporting blocks (7) are continuously arranged along the straight sections and curved sections of the serpentine water channel (53) of the wide-side water-cooled plate of the crystallizer; the chord length c of the bionic airfoil-type flow-disturbing self-supporting block (7) is 3 mm to 5 mm, the maximum thickness d is 0.8 mm to 1.5 mm, and the height of the self-supporting block is equal to the section thickness of the water channel.

5. The rectangular cross-section cast iron continuous casting crystallizer according to claim 4, characterized in that, The serpentine water channel (53) of the wide-side water-cooled plate of the crystallizer has a rectangular flow section, the equivalent width A of the serpentine water channel section is 10 mm to 30 mm, the thickness B of the serpentine water channel is 6 mm to 10 mm, and the thickness D of the partition wall in the middle of the serpentine water channel is 2 mm to 4 mm.

6. The method for manufacturing a water-cooled plate for a rectangular cross-section cast iron continuous casting crystallizer according to any one of claims 1-5, characterized in that, Specifically: Step 1, designing a three-dimensional model of the water-cooled plate of the crystallizer according to the cross-sectional dimension and solidification heat flux density distribution of the square-rectangular cast iron profile; Step 2, performing SLM additive manufacturing forming by using selective laser melting equipment according to the designed three-dimensional model of the water-cooled plate of the crystallizer; Step 3, performing powder cleaning treatment on the overall blank after printing, removing unmelted powder in the water channel; then placing the blank in a heat treatment furnace for stress relief annealing treatment; Step 4, performing finish machining on the fitting plane between the water-cooled plate of the crystallizer and the small transition plate (3) of the crystallizer to make the plane meet the sealing requirement, and carrying out a high-pressure water sealing hydraulic test.

7. The method for manufacturing a water-cooled plate for a rectangular cross-section cast iron continuous casting crystallizer according to claim 6, characterized in that, In step 2, the process parameters for SLM additive manufacturing are as follows: laser power is controlled between 200W and 400W; scanning speed is controlled between 600mm / s and 1200mm / s; powder layer thickness is set between 30μm and 50μm; and scanning spacing is controlled between 0.08mm and 0.12mm.

8. The method for manufacturing a water-cooled plate for a rectangular cross-section cast iron continuous casting crystallizer according to claim 6, characterized in that, In step 2, the preheating temperature of the substrate and the forming chamber is controlled between 100℃ and 200℃.

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