A method for improving the production of large size coil of rod

Abstract

The application discloses a production method for improving control of large-size coil shape of a wire rod, and belongs to the technical field of iron and steel manufacturing. The method comprises a whole-process rolling procedure of hot-rolled wire rod: heating furnace adding, high-pressure water phosphorus removing, rough rolling, final rolling, on-line cooling, finishing rolling, on-line cooling, reducing-diameter rolling, wire laying, cooling control, coil collecting, finishing, packing, packaging, and warehousing. Through positioning of the head of the wire rod, the rolling speed is periodically changed in the whole rolling process, the wire laying machine swing period and the rotating speed are calculated in combination with the target wire diameter and the wire height, the wire diameter of the wire rod is periodically changed in the wire laying process, the large and small coils are staggered and uniformly distributed after the coil collecting, the required wire height is obtained under the condition of fixed wire rod weight, and the coil shape is regular after the packing. The application discloses a wire laying machine swing period calculation formula, is suitable for existing tooling equipment, effectively avoids the wire rod scratch and the problems of disorderly wire and knotting in the subsequent processing, satisfies the individualized requirements of different customers on the wire diameter and the wire height, and significantly improves the product quality and the production efficiency.

Description

Technical Field

[0001] This invention belongs to the field of steel manufacturing technology, specifically relating to a production method for improving the control of the shape of large-diameter wire rods, which is particularly suitable for the hot rolling production of large-diameter wire rods of special steels such as high-carbon chromium bearing steel. Background Technology

[0002] Wire rod is an important product of the modern steel industry, widely used in construction, metal products, infrastructure and other fields. Most wire rods need to be heat-treated before use. Different furnace types have different requirements for the diameter and height of the wire rod. The regularity of the wire rod's coil shape directly affects the subsequent processing. If the coil shape is irregular, problems such as tangled wire and knots are likely to occur, which seriously reduces processing efficiency and product quality.

[0003] Currently, most industry-wide control measures for wire rod coil shape involve localized optimization. For example, the "A method for optimizing the tail speed increase of large-diameter wire rods" disclosed in application number 202210725648.X achieves tail speed increase optimization at the end of rolling by relay speed increase functions of the sizing mill, pinch rolls, and wire spinneret. This method can only eliminate the impact of tail speed increase on the finished coil shape, but it cannot achieve periodic speed changes in the early stage of rolling, nor can it fundamentally adjust the overall coil shape and coil height of the wire rod. This makes it difficult to meet the personalized needs of different customers for coil diameter and coil height, resulting in insufficient product competitive advantage.

[0004] Therefore, developing a production method that is compatible with existing tooling equipment, can control the wire rod shape throughout the entire rolling process, and can accurately obtain the target wire rod height under a fixed wire rod weight has become a technical problem that the industry urgently needs to solve. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a production method for improving the control of the coil shape of large-size wire rod, which is in contrast to the above-mentioned prior art. This method achieves precise control of the coil shape throughout the entire wire rod rolling process, so that the wire rod is evenly distributed in staggered layers after coiling, and the required coil height is obtained under the condition of fixed coil weight. At the same time, it avoids wire rod scratches and problems such as tangled threads and knots in subsequent processing, meets the personalized needs of different customers, and improves product quality and production efficiency.

[0006] The technical solution adopted by this invention to solve the above problems is: a production method for improving the control of large-size wire rod coil shape, the specific technical solution of which is as follows: 1. Entire rolling process The hot-rolled wire rod undergoes the following processes in sequence: heating furnace loading → high-pressure water descaling → rough rolling → final rolling → online controlled cooling → finish rolling → online controlled cooling → sizing rolling → wire drawing → controlled cooling → coiling → finishing → packaging → warehousing. Each process is operated according to conventional hot-rolling process parameters for steel, with precise control over head positioning, rolling speed, and wire drawing mill operating parameters.

[0007] 2. Wire rod head positioning and cycle speed change start During the rolling process, the head of the wire rod is positioned. A roller table position detection device ensures that the wire rod head falls precisely into the roller table at the nine o'clock position clockwise. This position is the optimal starting point for periodic speed changes, ensuring consistent control of the wire rod's shape during subsequent periodic speed changes. Once the head positioning is complete, periodic speed control of the rolling speed is immediately initiated.

[0008] 3. Parameter limitations for the spinning machine and spinning bend tube The wire drawing machine uses wire drawing discs with a specification of 1.00m-1.10m, and the diameter of the wire drawing bend is ≥1m. The diameter of the wire drawing bend orifice must not be less than the diameter of the wire rod d+5mm. This orifice design can effectively prevent the wire rod from contacting the inner wall of the wire drawing bend and causing abrasion during the wire drawing process, thus ensuring the surface quality of the wire rod. At the same time, the coil shape parameters after wire drawing are limited: minimum coil ≥0.85m, maximum coil ≤1.2m, and coil diameter after packaging ≤1.3m, to ensure that the coil shape is regular and suitable for subsequent heat treatment and processing procedures.

[0009] 4. Calculation of the oscillation period of the spinning machine Based on the target coil diameter and height, combined with the rolling speed and the parameters of the coil bending tube, the oscillation cycle of the coil spinning machine is calculated using a special calculation formula. The coil spinning machine operates at different speeds according to this cycle, achieving a precise match between the rolling speed and the coil spinning speed.

[0010] Core calculation formula: S=[(V1-V)+(V- V2)] / Dπ The definitions and relationships of the parameters in the formula are as follows: V1: Maximum linear speed of the spinning machine (m / s), V1=N1Dπ=V*(1+K); V2: Minimum linear velocity of the spinning machine (m / s), V2=N2Dπ=V*(1-K); S: Oscillation period of the spinning machine (s); N1: Maximum oscillation speed of the spinning machine (r / s); N2: Minimum oscillation speed of the spinning machine (r / s); V: Rolling speed (m / s); D: Diameter of the wire bending tube (m); K: Oscillation coefficient (unitless), K=(d1-d) / d; d1: Diameter of the wire bending tube (mm); d: Wire rod diameter (mm).

[0011] 5. Technical benefits of periodic speed change The wire drawing machine operates at variable speed according to the calculated oscillation cycle, which drives the rolling speed to change periodically. This causes the wire diameter to change regularly during the wire drawing process. When the wire falls onto the cooling roller table, it is distributed in a periodic pattern of alternating large and small rings. After coiling, the wire naturally forms a staggered and evenly distributed structure, avoiding stacking and compression between wire layers. Finally, after finishing and packaging, the wire height required by the customer is accurately obtained under the condition of fixed wire weight, and the overall ring shape is regular.

[0012] Compared with the prior art, the present invention has the following beneficial effects: This invention quantifies and correlates the oscillation cycle of the wire spinning machine with the rolling speed and the parameters of the wire spinning bend, and has invented a unique oscillation cycle calculation formula. Combined with the head positioning + periodic speed change control strategy throughout the rolling process, it achieves precise control of the wire rod ring shape throughout the entire process.

[0013] Existing technologies only focus on tail-end optimization at the end of rolling, while this invention recognizes that the regularity of the wire rod's coil shape and the controllability of its height depend on the regular changes in the coil diameter during the coiling process. By determining the starting point of the periodic speed change through head positioning, the consistency of speed control is ensured. By limiting the parameters of the coiler and the coiling bend, wire rod abrasion is avoided, while a reasonable range for coil diameter changes is set. Through the oscillation period calculation formula, dynamic matching between rolling speed and coiling speed is achieved, resulting in regular changes in coil diameter, ultimately achieving a uniform staggered distribution after coiling.

[0014] The technical solution of this invention is adaptable to the production of large-diameter wire rods ranging from Φ10mm to Φ25mm. It only requires adjusting parameters such as rolling speed and wire bending orifice diameter based on the wire rod diameter, and then recalculating using the oscillation period calculation formula, demonstrating strong versatility. Furthermore, this method does not require modification of existing hot rolling production line tooling equipment; it only requires writing the oscillation period calculation program and head positioning control program into the control system to achieve industrialized production, showing broad prospects for widespread application.

[0015] This invention solves the industry pain point that existing technologies cannot fundamentally control the coil shape and coil height of wire rod, meets the personalized needs of different customers, improves product quality and production efficiency, and has an important role in improving and promoting wire rod production technology in the steel manufacturing field. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the circular distribution of Φ22mm high carbon chromium bearing steel wire rod on the cooling roller conveyor after it is spun out in Embodiment 2 of the present invention. It can be seen that the wire rod is distributed in a periodic pattern of alternating large and small circles, without stacking or disordered wires. Figure 2 This is a schematic diagram of the finished ring shape of the Φ22mm high carbon chromium bearing steel wire rod after coiling in Embodiment 2 of the present invention. It can be seen that the wire rod is evenly distributed in staggered layers after coiling, the overall ring shape is regular, and the coil height is consistent. Detailed Implementation

[0017] The technical solution of the present invention will be described in more detail below with reference to preferred embodiments. However, these embodiments are merely descriptions of preferred implementations of the present invention and should not be construed as limiting the scope of the present invention.

[0018] All embodiments of the present invention are completed on a high-speed hot-rolling production line of a special steel wire rod plant, and the product is a large-size wire rod of high-carbon chromium bearing steel. Each embodiment follows the core technical solution of the present invention, and only adjusts the relevant parameters according to the specifications of the wire rod. Example 1

[0019] The specific steps for producing Φ12mm high-carbon chromium bearing steel wire rod are as follows: The wire rod is fed into a heating furnace → high-pressure water descaling → rough rolling → final rolling → online controlled cooling → finish rolling → online controlled cooling → sizing rolling, and then enters the wire drawing process. The rolling speed of this specification of wire rod is V=39.00m / s. During the rolling process, the head of the wire rod is positioned so that it falls into the roller table at the nine o'clock position clockwise, and then the cycle speed change is started. Select a spinning disc with a diameter of 1.05m, a spinning bend diameter D = 1.05m, and a spinning bend orifice diameter d1 = 18mm, satisfying d1 ≥ d + 5mm (18 ≥ 12 + 5). Calculate the relevant parameters: Swing coefficient K = (d1-d) / d = (18-12) / 18 = 1 / 3; The maximum linear speed of the spinning machine is V1 = V*(1+K) = 39*(1+1 / 3) = 52.00m / s; The minimum linear speed of the spinning machine is V2 = V*(1-K) = 39*(1-1 / 3) = 26.00m / s; The oscillation period of the spinning machine is S = [(V1-V) + (V-V2)] / Dπ = [(52.00-39.00) + (39.00-26.00)] / (1.05×3.1415) = 26 / 3.298675 = 7.88s; The wire spinning machine operates at a variable speed with an oscillation cycle of 7.88s. After the wire rod is spun, the minimum coil size is 0.90m and the maximum coil size is 1.15m, which meets the requirements of ≥0.85m and ≤1.2m. After controlled cooling and coiling, the wire rods are evenly distributed in staggered layers. After finishing and packaging, the packaged coil diameter is 1.26m≤1.3m. Eight coils of finished products are inspected. The coil height is 1230mm-1260mm, the inner diameter of the coil is 900mm-920mm, the coil shape is regular, and there are no scratches or tangled wires. Example 2

[0020] The specific steps for producing Φ22mm high-carbon chromium bearing steel wire rod are as follows: After the hot rolling process, the wire rod enters the wire drawing process. The rolling speed of this specification of wire rod is V=12.85m / s. After completing the wire rod head positioning, start the cycle speed change; Select a spinning disc with a diameter of 1.05m, a spinning bend diameter D = 1.05m, and a spinning bend orifice diameter d1 = 30mm, satisfying d1 ≥ d + 5mm (30 ≥ 22 + 5). Calculate the relevant parameters: Swing coefficient K = (d1 - d) / d = (30 - 22) / 30 = 4 / 15; The maximum linear speed of the spinning machine is V1 = V * (1 + K) = 12.85 × (1 + 4 / 15) = 16.28 m / s; The minimum linear speed of the spinning machine is V2 = V*(1-K) = 12.85×(1-4 / 15) = 9.42m / s; The oscillation period of the spinning machine is S = [(V1-V) + (V-V2)] / Dπ = [(16.28-12.85) + (12.85-9.42)] / (1.05×3.1415) = 6.86 / 3.298675 = 2.08s; The wire drawing machine operates at a variable speed with an oscillation cycle of 2.08s. After the wire rod is drawn, the minimum coil size is 0.91m and the maximum coil size is 1.18m, which meets the specification limits. After subsequent processes, the wire rod is packaged with a diameter of 1240mm-1260mm and a length of ≤1.3m. Eight rolls of finished product are inspected, and the coil height is 1170mm-1220mm, the inner diameter of the coil is 900mm-930mm, the coil shape is regular, the surface is free of scratches, and there are no problems with tangled threads or knots in subsequent processing.

[0021] Table 1. Inspection Results of Wire Rod Coil Shape and Coil Height

[0022] Summary of the effects of the examples The finished product inspection results of the above two embodiments show that the production method of the present invention can accurately control the coil shape and coil height of large-size wire rods of different specifications. The finished coil height and coil diameter have small dispersion, good coil shape regularity, and no surface scratches, tangled threads, or other problems. It fully meets the personalized needs of customers and verifies the effectiveness and practicality of the technical solution of the present invention.

[0023] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A production method for improving the control of large-diameter wire rod coil shape, characterized in that, Includes the following steps: The hot-rolled wire rod undergoes the following rolling process: heating furnace feeding → high-pressure water descaling → rough rolling → final rolling → online controlled cooling → finish rolling → online controlled cooling → sizing rolling → wire drawing → controlled cooling → coiling → finishing → packaging → warehousing. Based on the target coil diameter and coil height, the oscillation period and rotation speed of the coiler are calculated, and the coil shape is controlled online by the variable speed operation of the coiler. During the rolling process, the head of the wire rod is positioned so that the head of the wire rod falls into the roller table at the nine o'clock position clockwise. Then, the rolling speed is changed periodically, so that the wire rod diameter changes periodically during the winding process. After coiling, the wire rod is distributed in staggered circles of different sizes. After packaging, the required wire rod height is obtained under the condition of fixed wire weight.

2. The production method for improving control of large-diameter wire rod coil shape according to claim 1, characterized in that, The specifications of the spinning spool of the spinning machine are 1.00m-1.10m; the diameter of the spinning bend tube used in the spinning process is ≥1m, and the diameter of the spinning bend tube hole is ≥d+5mm of the wire rod diameter; the minimum circle size of the wire rod after spinning is ≥0.85m, the maximum circle size is ≤1.2m, and the circle diameter after the wire rod is packaged is ≤1.3m.

3. The production method for improving control of large-diameter wire rod coil shape according to claim 1, characterized in that, The relationship between the oscillation period S of the spinning machine, the rolling speed V, and the spinning machine rotation speed satisfies the formula: S=[(V1-V)+(V- V2)] / Dπ; Where V1 is the maximum linear velocity of the spinning machine, in m / s, V1=V*(1+K). V2 is the minimum linear velocity of the spinning machine, in m / s, V2=V*(1-K); S is the oscillation period of the spinning machine, in seconds; V is the rolling speed, in m / s; D is the diameter of the wire-spinning bend, in meters; K is the oscillation coefficient, which has no unit, K = (d1 - d) / d; d1 is the diameter of the wire-spinning bend, in mm; d is the diameter of the wire rod, in mm.

4. The production method for improving control of large-diameter wire rod coil shape according to claim 3, characterized in that, The relationship between the maximum linear velocity V1 of the spinning machine and the maximum oscillation speed N1 of the spinning machine is V1=N1Dπ, and the relationship between the minimum linear velocity V2 of the spinning machine and the minimum oscillation speed N2 of the spinning machine is V2=N2Dπ; where N1 is the maximum oscillation speed of the spinning machine, in r / s; and N2 is the minimum oscillation speed of the spinning machine, in r / s.

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