Super-large-diameter steel strand production equipment and production process

Abstract

The invention relates to a super-large-diameter steel strand production process which comprises the steps that a 1 * 19-wire Warrington structure is adopted for a steel strand, the nominal diameter of the steel strand is 34.6 mm, and the manufacturing process comprises the steps of wire rod selection, inspection and testing, acid pickling and passivation, inspection, drawing, semi-finished product inspection and testing, stranding, stabilizing treatment, layer winding, finished product inspection and testing, packaging and warehousing. In the wire rod selection procedure, wire rods of the same type and the same specification are adopted for the four wire distribution diameters, and the chemical components of the wire rods comprise 0.84%-0.860% of C, 0.75%-0.79% of Si, 0.72%-0.74% of Mn and 0.008%-0.012% of P; s: 0.0045% to 0.005%; the alloy comprises the following components in percentage by weight: 0.04 to 0.05 percent of Cr, 0.001 to 0.002 percent of Ni, 0.001 to 0.002 percent of Cu, and Fe and inevitable impurity elements. In the drawing process; the tensile strength of the center wire, the inner-layer wires, the outer-layer thin wires and the outer-layer thick wires after drawing reaches the grade of 2000 MPa. The method has the advantage that the strength of the produced steel strand is improved.

Description

[0001] This patent is a divisional patent of the following invention patent.

[0002] Submission Date: October 30, 2024

[0003] Authorization Date: March 3, 2026

[0004] Patent No.: CN119392232B

[0005] Invention Title: A Production Equipment and Process for Ultra-Large Diameter Steel Strand Technical Field

[0006] This application relates to the field of mining steel strand, and in particular to a production equipment and process for ultra-large diameter steel strand. Background Technology

[0007] Steel strand is a steel product made of multiple steel wires twisted together. It is often used in mining, bridges and other fields that require high-strength tension.

[0008] In the current production process of steel strands, a passivation process is often required. Specifically, the steel strands are immersed in a metal surface treatment agent, which adheres to the surface of the steel strands and forms a protective film, thereby increasing the corrosion resistance of the steel strands.

[0009] The current passivation process involves directly placing the steel strand into the metal surface treatment agent. However, with this method, after the steel strand has been repeatedly introduced into the passivation tank, it is difficult to accurately control the temperature inside the tank. This causes the metal surface treatment agent to cool down upon contact with the steel strand, resulting in a poorer passivation effect. Summary of the Invention

[0010] To improve the passivation effect of steel strands, this application provides a production equipment and process for ultra-large diameter steel strands.

[0011] In the first aspect, this application provides a production equipment for ultra-large diameter steel strands, which adopts the following technical solution:

[0012] A large-diameter steel strand production equipment includes: a passivation tank, a heating plate at the bottom of the passivation tank, two spaced-apart upper guide rollers inside the passivation tank, and a plurality of spaced-apart lower guide rollers at the middle position of the two upper guide rollers, with the plurality of lower guide rollers located below the two upper guide rollers. Heating components are provided in the directions away from each other on the two upper guide rollers. The heating components are used to heat the steel strand passing through the upper and lower guide rollers. The two lower guide rollers are connected to a lifting component for moving the two lower guide rollers and the heating plate upward when the metal surface treatment agent inside the passivation tank decreases.

[0013] By adopting the above technical solution, in actual use, the steel strand before entering the metal surface treatment agent is heated by the heating component, and the metal surface treatment agent inside the passivation tank is heated by the heating plate. This ensures that the metal surface treatment agent can maintain a temperature above 80°C inside the passivation tank and contact the steel strand, thereby reducing the phenomenon that the metal surface treatment agent is difficult to adhere to the steel strand due to the low temperature of the steel strand. Furthermore, heating the steel strand removed from the metal surface treatment agent by the heating component makes the metal surface treatment agent more uniform on the surface of the steel strand.

[0014] Optionally, the heating assembly includes a heating tube containing a heating liquid, and a fan is provided on the upper side of the heating tube for blowing air onto the steel strand below the heating tube.

[0015] By adopting the above technical solution, when it is necessary to heat the steel strand, the fan is turned on, and the fan drives the air through the heating tube to blow onto the steel strand, thereby realizing the heating operation of the steel strand.

[0016] Optionally, each heating tube is bent, and both ends of each heating tube are connected to the same heat exchange box. Each heat exchange box has two cavities that are respectively connected to the two ends of the heating tube. Each cavity of the heat exchange box has a push plate that slides against the inner wall of the cavity. Each push plate is threaded through and connected to a reciprocating screw. The end of each reciprocating screw passes through the side wall of the heat exchange box and is rotatably connected to the side wall of the heat exchange box. Each upper guide wheel is threaded through and fixedly connected to an upper connecting shaft. Each upper connecting shaft is connected to the adjacent reciprocating screw via a belt and a pulley. A heating plate is installed at the bottom of each heat exchange box.

[0017] By adopting the above technical solution, when the steel strand passes through the upper guide wheel, the upper guide wheel rotates and drives the upper connecting shaft to rotate. During the rotation of the upper connecting shaft, the connected reciprocating screw rotates. The two reciprocating screws inside the same heat exchange box drive the two connected push plates to move alternately, thereby alternately driving the heating liquid inside the heat exchange tube into the heat exchange box and from the heat exchange box into the heating tube. Since a heating plate is provided at the bottom of the heat exchange box, the heating liquid entering the heat exchange box can be heated, thereby reducing the phenomenon that the heating liquid inside the heating tube cools down during long-term use, making it difficult to heat the steel strand.

[0018] Optionally, a drive bevel gear is fixedly connected to one side of each of the upper guide wheels, each of the drive bevel gears meshes with a driven bevel gear, and each of the driven bevel gears is connected to the adjacent fan via a belt and a pulley and drives the fan to rotate.

[0019] By adopting the above technical solution, during the rotation of the upper guide wheel, the upper guide wheel drives the connected upper shaft to rotate. During the rotation of the upper shaft, the drive bevel gear rotates. During the rotation of the drive bevel gear, the driven bevel gear rotates. During the rotation of the driven bevel gear, the fan rotates. This reduces the waste of needing to add a drive device to drive the fan to rotate.

[0020] Optionally, the heating plate slides against the inner wall of the passivation tank. Multiple drive screws are fixedly connected to the bottom of the heating plate, and each drive screw corresponds to one of the multiple lower guide wheels. The lower end of each drive screw penetrates the bottom wall of the passivation tank and is threadedly connected to a drive pulley. Each drive pulley has lifting pulleys connected to opposite sides via lifting belts. A lifting screw is fixedly connected to one side of each lifting pulley. Each lifting screw is threadedly connected to a connecting block. Each lower guide wheel is penetrated and rotatably connected to a lower connecting shaft. The end of each lower connecting shaft rotates and slides into the interior of an adjacent connecting block. One side of each lower connecting shaft abuts against a stop block. The abutting sidewall of each stop block gradually tilts away from the adjacent lower connecting shaft from bottom to top.

[0021] By adopting the above technical solution, when the metal surface treatment agent inside the passivation tank decreases, the heating plate moves upward under the drive of the pressure spring. During the upward movement of the heating plate, the driving screw connected to it moves. During the movement of the driving screw, the driving pulley connected to it rotates. During the rotation of the driving pulley, the lifting pulley connected to it rotates. During the rotation of the lifting pulley, the lifting screw connected to it rotates. During the rotation of the lifting screw, the connecting block connected to it moves. This allows the connecting block to drive the lower connecting shaft to move upward. Furthermore, due to the presence of the abutment block, multiple lower connecting shafts can move in a direction away from each other, thereby increasing the length of the steel strands under the multiple lower guide wheels. This reduces the phenomenon that when the metal surface treatment agent decreases, the contact time between the steel strands and the metal surface treatment agent is shortened, making it difficult for the metal surface treatment agent to adhere to the surface of the steel strands.

[0022] Secondly, this application provides a manufacturing process for ultra-large diameter steel strands, employing the following technical solution:

[0023] A process for producing ultra-large diameter steel strands, wherein the steel strands adopt a 1×19 wire Warington structure, with 19 wires twisted at once, using a twist ratio of 12.5. The diameter of the center wire is 7.71 mm, the diameter of the outer coarse wire is 8.04 mm, the diameter of the outer fine wire is 6.04 mm, the diameter of the inner wire is 7.4 mm, the nominal diameter of the steel strand is 34.6 mm, the upper deviation of the nominal diameter is +0.40 mm, and the lower deviation of the nominal diameter is -0.15 mm.

[0024] The manufacturing process is as follows: selection of wire rod → inspection and testing → pickling and passivation → inspection → drawing → semi-finished product inspection and testing → twisting → stabilization treatment → layer winding → finished product inspection and testing → packaging → warehousing. In the wire rod selection process, the four wire diameters use wire rods of the same grade and specification, with the following chemical composition: C: 0.84-0.860%, Si: 0.75-0.79%, Mn: 0.72-0.74%, P: 0.008-0.012%, S: 0.0045-0.005%, Cr: 0.04-0.05%, Ni: 0.001-0.002%, Cu: 0.001-0.002%, and Fe, as well as unavoidable impurity elements.

[0025] In the drawing process, the center wire is drawn from 15.0mm wire rod to 7.71mm in 9 passes, the outer coarse wire is drawn from 15.0mm wire rod to 8.04mm in 8 passes, the inner wire is drawn from 15.0mm wire rod to 7.4mm in 9 passes, and the outer fine wire is drawn from 15.0mm wire rod to 6.04mm in 11 passes. The tensile strength of the raw materials used for the four types of wires is ≥1310MPa. The tensile strength of the center wire, inner wire, outer fine wire, and outer coarse wire after drawing reaches the 2000MPa level.

[0026] By adopting the above technical solution, it is possible to produce steel strands with a diameter of 34.6 mm, which can effectively improve the strength of the steel strands and make them suitable for more application scenarios.

[0027] Optionally, the nominal tensile strength of the steel strand is 1770-1960MPa, corresponding to a maximum force of not less than 1395-1545kN, a 0.2% yield strength of not less than 1228kN, a total elongation at maximum force ≥3.5%, and a straightness ≤14mm.

[0028] By adopting the above technical solutions, steel strands can withstand stronger tensile stress scenarios.

[0029] Optionally, in the pickling and passivation process, pickling removes the oxide scale; after pickling, it is rinsed with clean water, and the passivation process temperature is not lower than 80℃, forming a carrier on the surface, and the passivation film plays a role in lubrication and rust prevention.

[0030] By adopting the above technical solution, the steel strand can be fully passivated.

[0031] Optionally, a twist pitch of 12.5 times is used for twisting, with a V-groove design, a groove width of 38mm, and a groove depth of 42mm; the inner hole of the pressing die used in the twisting process is 36mm.

[0032] By adopting the above technical solutions, the finished steel strand can be made more stable during use.

[0033] Optionally, in the stabilization process, the tempering temperature is 405-415℃, the production line speed is less than 9m / min, and the tension of the steel strand is controlled at 30%-35% of the steel strand threshold force; the cooling after tempering adopts a direct cooling immersion cooling method.

[0034] By adopting the above technical solution, the steel strand can withstand greater forces during subsequent use.

[0035] In summary, this application includes at least one of the following beneficial technical effects:

[0036] 1. By increasing the nominal diameter of the steel strand to 34.6 mm, the steel strand can be used in scenarios requiring greater tensile strength;

[0037] 2. By installing heating components on the opposite sides of the two upper guide wheels, the phenomenon that the steel strand is difficult to adhere to the metal surface treatment agent due to its low temperature is reduced.

[0038] 3. By setting up lifting components, the phenomenon that the steel strands are difficult to fully adhere to the metal surface treatment agent after the metal surface treatment agent is reduced inside the passivation pool is reduced. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application.

[0040] Figure 2 This is a cross-sectional view of the overall structure of an embodiment of this application.

[0041] Figure 3 This is a schematic diagram showing the connection relationship between the passivation tank and the heat exchange box in an embodiment of this application.

[0042] Figure 4 This is a cross-sectional view highlighting the connection relationship between the heat exchange box and the heating tube in an embodiment of this application.

[0043] Figure 5 This is a schematic diagram of the steel strand structure according to an embodiment of this application.

[0044] Explanation of reference numerals in the attached drawings: 1. Passivation tank; 11. Upper guide wheel; 12. Lower guide wheel; 13. Upper connecting shaft; 14. Lower connecting shaft; 141. Baffle plate; 2. Heating plate; 3. Heating assembly; 31. Heating tube; 32. Fan; 33. Heat exchange box; 331. Baffle plate; 332. Push plate; 333. Reciprocating screw; 334. Push pulley; 335. Drive pulley; 336. Push belt; 34. Heating plate; 35. 36. Driven bevel gear; 37. Drive shaft; 38. Drive pulley; 381. Connecting belt; 39. Heating pulley; 4. Lifting assembly; 41. Pressure spring; 42. Drive screw; 43. Drive pulley; 44. Lifting pulley; 441. Lifting belt; 45. Lifting screw; 46. Connecting block; 47. Abutment block; 5. Center screw; 6. Outer coarse screw; 7. Inner screw; 8. Outer fine screw. Detailed Implementation

[0045] The following is in conjunction with the appendix Figure 1 -Appendix Figure 5 This application will be described in further detail.

[0046] This application discloses an equipment for producing ultra-large diameter steel strands. (Refer to...) Figure 1 and Figure 2 The system includes a passivation tank 1, which contains a metal surface treatment agent. A horizontally positioned heating plate 2 is located at the bottom of the passivation tank 1, and the heating plate 2 moves vertically up and down along the inner wall of the passivation tank 1. Inside the passivation tank 1, two opposing upper guide wheels 11 are positioned at intervals on the same horizontal plane. Multiple lower guide wheels 12 are located below the middle position of the two upper guide wheels 11; in this embodiment, two lower guide wheels 12 are provided, and they are positioned at intervals on the same horizontal plane.

[0047] Heating components 3 are provided on the opposite sides of the two upper guide rollers 11. The heating components 3 are used to heat the passing steel strand. The two lower guide rollers 12 are connected to lifting components 4. The lifting components 4 are used to drive the two lower guide rollers 12 and the heating plate 2 upward when the metal surface treatment agent inside the passivation tank 1 decreases.

[0048] In practical use, the steel strand is passed sequentially through one upper guide roller 11, two lower guide rollers 12, and another upper guide roller 11. This allows the steel strand to adhere to the metal surface treatment agent under the influence of the two lower guide rollers 12, achieving passivation of the steel strand. Furthermore, due to the presence of the heating component 3 and the heating plate 2, the metal surface treatment agent and the steel strand are kept at a temperature of 80°C or higher, allowing the metal surface treatment agent to adhere more evenly to the surface of the steel strand for treatment.

[0049] Furthermore, due to the presence of the lifting component 4, when the metal surface treatment agent inside the passivation tank 1 decreases, the heating plate 2 and the two lower guide wheels 12 are driven to move upward, so that the steel strand can still be fully coated with the metal surface treatment agent when the metal surface treatment agent inside the passivation tank 1 decreases.

[0050] Reference Figure 2 The heating component 3 includes a heating tube 31 horizontally arranged above the steel strand. In this embodiment, each heating tube 31 is a U-shaped heating tube 31, and a fan 32 is provided on the upper side of the heating tube 31. The fan 32 is used to blow air downwards.

[0051] Reference Figure 3 and Figure 4 Each heating tube 31 has two ends connected to a horizontally positioned heat exchange box 33, and a heating plate 34 is fixedly connected to the bottom of the heat exchange box 33. A partition 331 is fixedly connected inside the heat exchange box 33, dividing the interior of the heat exchange box 33 into two independent cavities. The two cavities of the heat exchange box 33 correspond one-to-one with the two ends of the heating tube 31, and the end of each heating tube 31 is connected to the interior of its corresponding cavity.

[0052] Each cavity of the heat exchange box 33 is equipped with a vertically arranged push plate 332, and each push plate 332 is threaded through and connected to a reciprocating screw 333. Each reciprocating screw 333 is perpendicular to the push plate 332 to which it is connected. The end of each reciprocating screw 333 away from the connected heating tube 31 passes through the side wall of the heat exchange box 33 and is rotatably connected to the side wall of the heat exchange box 33. A push pulley 334 is fixedly sleeved on the end of each reciprocating screw 333 that passes through the heat exchange box 33.

[0053] Each upper guide wheel 11 is penetrated and fixedly connected to an upper connecting shaft 13. The end of each upper connecting shaft 13 penetrates the side wall of the adjacent passivation tank 1 and is rotatably connected to the side wall of the passivation tank 1. A drive pulley 335 is fixedly connected to one end of the upper connecting shaft 13 near the heat exchange box 33. The drive pulley 335 is interconnected with two adjacent push pulleys 334 through a push belt 336.

[0054] During use, the upper guide wheel 11 rotates, driving the upper connecting shaft 13 to rotate. The upper connecting shaft 13 rotates, driving the drive pulley 335 to rotate. The drive pulley 335 rotates, driving the connected multiple push pulleys 334 to rotate. Each push pulley 334 rotates, driving the connected reciprocating screw 333 to rotate. The two reciprocating screws 333 drive the two push plates 332 to move back and forth alternately, thereby driving the alternating exchange of heating liquid inside the heating tube 31 and heating liquid inside the heat exchange box 33. Furthermore, since the heat exchange box 33 is equipped with a heating plate 34 at the bottom, the heating tube 31 can maintain an appropriate temperature for heating the steel strand.

[0055] Reference Figure 1 and Figure 2 The heating assembly 3 also includes a drive bevel gear 35 fixedly connected to the end of the upper shaft 13 away from the end connected to the drive pulley 335. One side of the drive bevel gear 35 is meshed with a driven bevel gear 36, and the upper side of the driven bevel gear 36 is fixedly connected to a transmission shaft 37. The upper end of the transmission shaft 37 is fixedly connected to a drive pulley 38, and one side of the drive pulley 38 is provided with a heating pulley 39 fixedly connected to the fan 32. The drive pulley 38 and the heating pulley 39 are fitted with the same connecting belt 381.

[0056] During the rotation of the upper guide wheel 11, the upper guide wheel 11 drives the drive bevel gear 35 to rotate through the upper connecting shaft 13. During the rotation of the drive bevel gear 35, the drive bevel gear 35 drives the connected driven bevel gear 36 to rotate. After the driven bevel gear 36 rotates, it drives the connected transmission shaft 37 to rotate. During the rotation of the transmission shaft 37, it drives the connected drive pulley 38 to rotate. The drive pulley 38 drives the heating pulley 39 and the fan 32 to rotate, thereby realizing the process of heating the steel strand by blowing air through the fan 32 and the air passing through the heating tube 31.

[0057] The lifting assembly 4 includes multiple pressure springs 41 that are fixedly connected between the heating plate 2 and the bottom wall of the passivation tank 1.

[0058] The lifting assembly 4 also includes multiple drive screws 42 fixedly connected to the lower side of the heating plate 2. In this embodiment, two drive screws 42 are provided, and the two drive screws 42 are correspondingly arranged with the two lower guide wheels 12. Each drive screw 42 is vertically arranged, and the lower end of each drive screw 42 penetrates the bottom wall of the passivation tank 1 and is slidably connected to the bottom wall of the passivation tank 1. One end of each drive screw 42 penetrating the bottom wall of the passivation tank 1 is threadedly sleeved with a drive pulley 43, and each drive pulley 43 has a lifting pulley 44 connected to its opposite sides via a lifting belt 441.

[0059] Each lifting pulley 44 is fixedly connected to a vertically arranged lifting screw 45 on its upper side, and each lifting screw 45 is threaded with a connecting block 46 on its exterior.

[0060] Each lower guide wheel 12 is rotatably connected to a lower connecting shaft 14. The end of each lower connecting shaft 14 passes through the side wall of the adjacent passivation tank 1 and is rotatably and slidably connected to the side wall of the passivation tank 1. The end of each lower connecting shaft 14 is slidably inserted into the corresponding connecting block 46 and is slidably connected to the connecting block 46 in the horizontal direction. A baffle plate 141 is fixedly sleeved on one end of each lower connecting shaft 14 that passes through the passivation tank 1. The side of each baffle plate 141 near the passivation tank 1 is slidably connected to the outer wall of the passivation tank 1 and is used to block the through hole opened on the side wall of the passivation tank 1 for the movement of the lower connecting shaft 14.

[0061] A stop block 47 is also provided between the ends of the two lower connecting shafts 14 near the connecting block 46. In this embodiment, the vertical cross section of the stop block 47 is an isosceles triangle, and the included angle of the two equilateral sides of the isosceles triangle is vertically downward between the two lower connecting shafts 14. Each lower connecting shaft 14 abuts against the side wall of the adjacent stop block 47, and the side wall of the stop block 47 abutted by each lower connecting shaft 14 is inclined from top to bottom towards the other lower connecting shaft 14.

[0062] In the actual production process, as the metal surface treatment agent inside the passivation tank 1 gradually decreases, the heating plate 2 gradually moves upward under the drive of multiple pressure springs 41. During the upward movement of the heating plate 2, the two connected drive screws 42 move upward.

[0063] As the drive screw 42 moves upward, it drives the connected drive pulley 43 to rotate. As the drive pulley 43 rotates, it drives the connected lifting pulley 44 to rotate. As the lifting pulley 44 rotates, it drives the connected lifting screw 45 to rotate. As the lifting screw 45 rotates, it drives the connected connecting block 46 to move upward. As the connecting block 46 moves upward, it drives the connected lower connecting shaft 14 to move upward. Due to the presence of the abutment block 47, the lower connecting shaft 14 moves upward, causing the two lower connecting shafts 14 to move away from each other. This ensures that when the metal surface treatment agent inside the passivation tank 1 decreases, the steel strand can maintain its original immersion length in the metal surface treatment agent.

[0064] The implementation principle of the ultra-large diameter steel strand production equipment in this application embodiment is as follows: when the steel strand needs to be passivated, the steel strand will be sequentially overlapped on one side of one upper guide wheel 11, two lower guide wheels 12 and another upper guide wheel 11, so that the steel strand can be fully immersed in the metal surface treatment agent for passivation treatment.

[0065] Before the steel strand enters the metal surface treatment agent or after it is removed from the metal surface treatment agent, the steel strand is heated by the fan 32 and the heating tube 31, so that the steel strand can be fully treated by the metal surface treatment agent.

[0066] Furthermore, due to the presence of the lifting component 4, after the metal surface treatment agent inside the passivation pool 1 is reduced, the lifting component 4 can drive the heating plate 2 and the lower guide wheel 12 to move upward, so that the steel strand can still be fully immersed in the metal surface treatment agent.

[0067] This application also discloses a production process for ultra-large diameter steel strand, including: the steel strand adopts a 1×19 wire Warington structure, with 19 wires twisted at one time, using a twist ratio of 12.5, the diameter of the center wire 5 is 7.71mm, the diameter of the outer coarse wire 6 is 8.04mm, the diameter of the outer fine wire 8 is 6.04mm, the diameter of the inner wire 7 is 7.4mm, the nominal diameter of the steel strand is 34.6mm, the upper deviation of the nominal diameter is +0.40mm, and the lower deviation of the nominal diameter is -0.15mm;

[0068] The manufacturing process is as follows: selection of wire rod → inspection and testing → pickling and passivation → inspection → drawing → semi-finished product inspection and testing → twisting → stabilization treatment → layer winding → finished product inspection and testing → packaging → warehousing. In the wire rod selection process, the four wire diameters use wire rods of the same grade and specification, with the following chemical composition: C: 0.84-0.860%, Si: 0.75-0.79%, Mn: 0.72-0.74%, P: 0.008-0.012%; S: 0.0045-0.005%; Cr: 0.04-0.05%, Ni: 0.001-0.002%, Cu: 0.001-0.002%, and Fe, as well as unavoidable impurity elements.

[0069] In the drawing process, the center wire 5 is drawn from 15.0mm wire rod to 7.71mm in 9 passes, the outer coarse wire 6 is drawn from 15.0mm wire rod to 8.04mm in 8 passes, the inner wire 7 is drawn from 15.0mm wire rod to 7.4mm in 9 passes, and the outer fine wire 8 is drawn from 15.0mm wire rod to 6.04mm in 11 passes. The tensile strength of the raw materials used for the four types of wires is ≥1310MPa. The tensile strength of the center wire 5, inner wire 7, outer fine wire 8, and outer coarse wire 6 after drawing reaches the level of 2000MPa.

[0070] The nominal tensile strength of the steel strand is 1770-1960MPa, corresponding to a maximum force of not less than 1395-1545kN, a 0.2% yield strength of not less than 1228kN, a total elongation at maximum force ≥3.5%, and a straightness ≤14mm.

[0071] The wire drawing machine employs 11 spools, increasing the feed diameter and enhancing wire toughness. This ensures the stability of wire strength and improves the performance and strength of the finished steel strand. In the twisting process, the JXN1×19 low-relaxation prestressed steel strand equipment is used. This equipment utilizes a 19-spool skip-rope process, ensuring the steel strand is tight and not loose. Twisting is performed with a 12.5-fold twist pitch, employing a V-groove design with a groove width of 38mm and a groove depth of 42mm; the inner hole of the pressure die used in the twisting process is 36mm.

[0072] In the pickling and passivation processes, pickling removes the oxide scale; after pickling, the surface is rinsed with clean water. The passivation process temperature is not lower than 80℃, forming a carrier layer on the surface. The passivation film acts as a lubricant and prevents rust. In the stabilization treatment process, the tempering temperature is 405~415℃, the production line operating speed is less than 9m / min, and the tension of the steel strand is controlled at 30%-35% of the maximum force of the steel strand. After tempering, the cooling method is direct cooling immersion.

[0073] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A manufacturing process for ultra-large diameter steel strand, characterized in that, include: The steel strand adopts a 1×19 wire Warington structure, with 19 wires twisted at once and a twist pitch of 12.5 times. The diameter of the center wire (5) is 7.71 mm, the diameter of the outer coarse wire (6) is 8.04 mm, the diameter of the outer fine wire (8) is 6.04 mm, the diameter of the inner wire (7) is 7.4 mm, the nominal diameter of the steel strand is 34.6 mm, the upper deviation of the nominal diameter is +0.40 mm, and the lower deviation of the nominal diameter is -0.15 mm. The manufacturing process is as follows: selection of wire rod → inspection and testing → pickling and passivation → inspection → drawing → semi-finished product inspection and testing → twisting → stabilization treatment → layer winding → finished product inspection and testing → packaging → warehousing. In the wire rod selection process, the four wire diameters use wire rods of the same grade and specification, with the following chemical composition: C: 0.84-0.860%, Si: 0.75-0.79%, Mn: 0.72-0.74%, P: 0.008-0.012%; S: 0.0045-0.005%; Cr: 0.04-0.05%, Ni: 0.001-0.002%, Cu: 0.001-0.002%, and Fe, as well as unavoidable impurity elements. In the drawing process, the center wire (5) is drawn from 15.0mm wire rod to 7.71mm in 9 passes, the outer coarse wire (6) is drawn from 15.0mm wire rod to 8.04mm in 8 passes, the inner wire (7) is drawn from 15.0mm wire rod to 7.4mm in 9 passes, and the outer fine wire (8) is drawn from 15.0mm wire rod to 6.04mm in 11 passes; the tensile strength of the raw materials used for the four types of wires is ≥1310MPa; the tensile strength of the center wire (5), inner wire (7), outer fine wire (8) and outer coarse wire (6) after drawing reaches the level of 2000MPa; The ultra-large diameter steel strand production process is applied to ultra-large diameter steel strand production equipment. The ultra-large diameter steel strand production equipment includes a passivation tank (1). The bottom of the passivation tank (1) is provided with a heating plate (2). The passivation tank (1) is provided with two spaced upper guide wheels (11). The middle position of the two upper guide wheels (11) is provided with multiple spaced lower guide wheels (12). The multiple lower guide wheels (12) are located below the two upper guide wheels (11). The two upper guide wheels (11) are provided with heating components (3) in directions away from each other. The heating components (3) are used to heat the steel strand passing through the upper guide wheels (11) and the lower guide wheels (12). The two lower guide wheels (12) are connected to a lifting component (4) for driving the two lower guide wheels (12) and the heating plate (2) to move upward when the metal surface treatment agent inside the passivation tank (1) decreases.

2. The manufacturing process for ultra-large diameter steel strand according to claim 1, characterized in that: The nominal tensile strength of the steel strand is 1770-1960MPa, corresponding to a maximum force of not less than 1395-1545kN and a 0.2% yield strength of not less than 1228kN; the total elongation at maximum force is ≥3.5%; and the straightness is ≤14mm.

3. The production process for ultra-large diameter steel strand according to claim 1, characterized in that: In the pickling and passivation processes, pickling removes the oxide scale; after pickling, it is rinsed with clean water. The passivation process temperature is not lower than 80℃, forming a carrier layer on the surface. The passivation film plays a role in lubrication and rust prevention.

4. The production process for ultra-large diameter steel strand according to claim 1, characterized in that: Twisting is performed using a 12.5 times twist pitch, with a V-groove design, a groove width of 38mm, and a groove depth of 42mm; the inner hole of the pressing die used in the twisting process is 36mm.

5. The manufacturing process for ultra-large diameter steel strand according to claim 1, characterized in that: In the stabilization process, the tempering temperature is 405-415℃, the production line speed is less than 9m / min, and the tension of the steel strand is controlled at 30%-35% of the steel strand threshold force. The cooling after tempering adopts a direct cooling immersion method.

6. A production process for ultra-large diameter steel strand according to any one of claims 1 to 5, characterized in that: The lifting assembly (4) includes multiple pressure springs (41) fixedly connected between the heating plate (2) and the bottom wall of the passivation pool (1).

7. A production process for ultra-large diameter steel strand according to any one of claims 1 to 5, characterized in that: The heating assembly (3) includes a heating tube (31), which contains a heating liquid. A fan (32) is provided on the upper side of the heating tube (31), and the fan (32) is used to blow air onto the steel strand below the heating tube (31).

8. The production process for ultra-large diameter steel strand according to claim 7, characterized in that: Each heating tube (31) is bent, and both ends of each heating tube (31) are connected to the same heat exchange box (33). Each heat exchange box (33) has two cavities that are respectively connected to the two ends of the heating tube (31). Each cavity of the heat exchange box (33) has a push plate (332) that slides against the inner wall of the cavity. Each push plate (332) is threaded through and connected to a reciprocating screw (333). The end of each reciprocating screw (333) passes through the side wall of the heat exchange box (33) and is rotatably connected to the side wall of the heat exchange box (33). Each upper guide wheel (11) is threaded through and fixedly connected to an upper connecting shaft (13). Each upper connecting shaft (13) is connected to the adjacent reciprocating screw (333) through a belt and pulley. A heating plate (34) is installed at the bottom of each heat exchange box (33).

9. A process for producing ultra-large diameter steel strand according to any one of claims 1 to 5, wherein the heating plate (2) slides against the inner wall of the passivation tank (1), and a plurality of drive screws (42) are fixedly connected to the bottom of the heating plate (2), the plurality of drive screws (42) are correspondingly arranged with a plurality of lower guide wheels (12), the lower end of each drive screw (42) penetrates the bottom wall of the passivation tank (1) and is threadedly fitted with a drive pulley (43), and each drive pulley (43) has a lifting pulley (44) connected to its opposite sides via a lifting belt (441). Each of the lifting pulleys (44) is fixedly connected to one side with a lifting screw (45), each of the lifting screws (45) is threaded with a connecting block (46), and each of the lower guide pulleys (12) is rotatably connected to a lower connecting shaft (14) through the middle. The end of each lower connecting shaft (14) is rotatably and slidably inserted into the interior of the adjacent connecting block (46), and each of the lower connecting shafts (14) is abutted by a stop block (47) on one side. The abutting sidewall of each stop block (47) and the lower connecting shaft (14) gradually tilts away from the adjacent lower connecting shaft (14) from bottom to top.

10. A production process for ultra-large diameter steel strand according to any one of claims 1 to 5, characterized in that: Each of the upper guide wheels (11) is fixedly connected to one side of a drive bevel gear (35), each of the drive bevel gears (35) meshes with a driven bevel gear (36), and each of the driven bevel gears (36) is connected to the adjacent fan (32) via a belt and a pulley and drives the fan (32) to rotate.

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