Wire and bar high-precision dynamic control method and four-roller reducing and sizing rolling system

Abstract

The invention relates to a high-precision dynamic control method for wires and bars and a four-roller reducing and sizing rolling system, and belongs to the technical field of steel rolling. Aiming at the problems of insufficient dimensional precision, surface defects and low ovality of the existing two-roller and three-roller reducing and sizing mill, the invention provides a scheme for integrating a reducing rolling mill unit and a four-roller sizing mill, the single-pass compression ratio of the reducing rolling mill is 1.10-1.35, the single-pass compression ratio of the four-roller sizing mill is 1.001-1.10, and + / -0.001 mm precision control is realized by combining a dynamic roll gap adjusting system. Through an ellipse-circle-multi-section arc pass system, a roll gap compensation algorithm and Ki integral, the dimensional deviation is corrected in real time, finally, the dimensional precision of a finished wire and bar reaches + / -0.05 mm, the ovality is smaller than 0.05, the rolling speed is 140 m / s and 25 m / s at most, the service life of a roll collar is prolonged by 30%, and the production cost is reduced by 15%.

Description

Technical Field

[0001] The present invention belongs to the technical field of steel rolling, and relates to a high-precision dynamic control method for wire rod and bar products and a four-high reducing and sizing rolling system. Background Art

[0002] In the technical field of steel rolling, wire rod and bar products, as key basic materials in industries such as automobiles, bridges, and rail transit, their dimensional accuracy and surface quality directly affect the performance of downstream applications. In traditional production processes, high-speed wire rods mostly use two-high reducing and sizing mills, and size control is achieved through single-pass large reduction rolling. However, due to the symmetric characteristics of the two-high pass, the highest dimensional accuracy of the finished product can only reach ±0.1 mm, and the ovality index is difficult to break through 0.05. For bar production, although the three-high reducing and sizing mill can partially improve size uniformity, the rolled products are prone to near-triangular cross-section defects after rolling, and the surface blue line problem is prominent. The finished product accuracy is limited to the level of ±0.12 mm. In the prior art, whether it is a two-high or three-high mill, there is a bottleneck in the contradiction between rolling speed and accuracy. For example, when the rolling speed of wire rods exceeds 120 m / s, the wear of the roll rings intensifies, resulting in size fluctuations exceeding the allowable tolerance. After the rolling speed of bars is increased to 25 m / s, the problem of roll gap drift caused by uneven temperature drop of the rolled piece deteriorates significantly.

[0003] In addition, traditional rolling systems have inherent defects in dynamic control. The mechanical roll gap adjustment mechanism of the two-high mill has insufficient response speed and cannot compensate for size deviations caused by rolling force fluctuations in real time. Although the three-high mill uses hydraulic servo control, its closed-loop feedback only relies on rolling force sensors and lacks multi-dimensional data fusion of temperature and topography. When the temperature difference between the core and surface of the rolled piece exceeds 30 °C, the roll gap correction lags by more than 50 milliseconds. In terms of roll materials, the hardness index of existing tungsten carbide roll rings is generally lower than HRC65. When rolling high-strength steel grades, the steel passing volume per single groove is less than 1000 tons, and frequent roll changes result in a production efficiency reduction of more than 15%. In the field of pass design, the oval-round pass system is prone to stress concentration during multi-pass rolling. Especially in the sizing stage, the matching accuracy of the inner and outer arc angles of the traditional arc pass is insufficient, resulting in an increase in the edge crack defect rate of the rolled piece to 0.3‰.

[0004] In view of the above technical bottlenecks, the industry urgently needs a new rolling system integrating a high-rigidity mill structure, multi-parameter coordinated control, and optimized pass design to break through the comprehensive limitations of accuracy, speed, and cost. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a high-precision dynamic control method for wire rod and bar products and a four-high reducing and sizing rolling system. The rolling mill unit and the high-precision pass design method have low design and construction costs, are easy to realize industrial production, have low operating costs, high product dimensional accuracy, and excellent surface quality, and have obvious economic benefits.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A high-precision production method for wire rod and bar, comprising the following steps:

[0008] Initial setting stage: Load the preset roll gap curve S0 = f(D, σ) according to the blank specifications, and set the single-pass compression ratio range of the reducing rolling mill group to 1.10 - 1.35; the single-pass compression ratio range of the four-high sizing rolling mill group to 1.001 - 1.10; where D is the finished diameter and σ is the material deformation resistance, and the loading algorithm includes:

[0009]

[0010] where, K1 = 120 - 180 MPa·mm 2 , K2 = 0.3 - 0.8 mm;

[0011] Dynamic adjustment stage: Real-time collect the size deviation Δd of the rolled piece and the temperature change amount ΔT, and trigger roll gap compensation when |Δd| ≥ 0.05 mm:

[0012]

[0013] where K p is the proportionality coefficient, K p = 0.5 - 1.5; K i is the integral coefficient, K i = 0.01 - 0.1, K d is the differential coefficient, K d = 0.05 - 0.2; β is the temperature coupling correction term;

[0014] Roll profile correction stage: Perform axial movement calculation every 100 - 400 rolls:

[0015]

[0016] And synchronously adjust the cooling water flow rate gradient ΔQ = 2 - 15%, where N is the cumulative number of rolled pieces.

[0017] Furthermore, the dynamic adjustment stage further includes a rolling force feedforward compensation algorithm, and the stiffness K stiffness of the four-high sizing rolling mill ≥ 150 t / mm, and the compensation response time ≤ 5 ms:

[0018]

[0019] where α = 1.01 - 1.35 is the material flow stress correction factor.

[0020] Further, the temperature coupling correction term β is calculated by a temperature-gap coupling control algorithm, specifically:

[0021] β = ΔT × 0.003 mm / °C

[0022] Among them, the real-time calculation of the temperature compensation coefficient β is based on the data of the infrared temperature measurement array, with a temperature resolution of ±2 °C and a data sampling frequency of ≥2000 Hz.

[0023] Further, the single-pass reduction ratio of the pipe reducing and sizing mill is dynamically adjusted by a control algorithm, where:

[0024] Reduction ratio of the pipe reducing mill:

[0025]

[0026] Reduction ratio of the four-high sizing mill:

[0027]

[0028] Where D input is the diameter of the rolled piece at the inlet of the pipe reducing mill, D output is the target diameter of the rolled piece at the outlet of the pipe reducing mill, D input-s is the diameter of the rolled piece at the inlet of the four-high sizing mill, D final is the diameter of the final finished rolled piece.

[0029] Further, the pass optimization algorithm of the four-high sizing mill includes:

[0030] Calculating the inner arc angle of the multi-segment arc pass:

[0031]

[0032] Outer arc angle:

[0033]

[0034] Where D final is the finished product diameter, in mm, and the angle calculation error is ≤ ±0.5°.

[0035] A wire rod reducing and sizing rolling system includes:

[0036] A pipe reducing mill, including a cantilever type pipe reducing mill or a short stress line type pipe reducing mill, with adjacent stands arranged alternately and a stiffness ≥ 100 t / mm, and the roll axes of the pipe reducing mill are in a horizontal or vertical direction with the rolling line;

[0037] A four-high sizing mill, configured in one of the following two forms:

[0038] (a) Single-stand four-high sizing mill, with the roll axis arranged horizontally or vertically with respect to the rolling line, and the surface hardness of the rolls ≥ HRC68;

[0039] (b) Double-stand four-high sizing mill, with adjacent stands arranged alternately at 45° and 135°, and the centerline included angle being 90° ± 1°;

[0040] Dynamic roll gap adjustment system, connected to the roll bearing seats of the reducing mill group and the sizing mill group through a mechanical coupling method, for real-time regulation of the roll gap size;

[0041] Multi-parameter feedback unit, including:

[0042] Laser diameter gauge, installed at the outlet of the reducing mill group and the outlet of the sizing mill group, and signal-connected to the dynamic roll gap adjustment system;

[0043] Infrared temperature measurement array, arranged at the inlet and outlet of each rolling mill, and communicating with the central controller through the PROFINET protocol;

[0044] Rolling force sensor, integrated between the rolling mill housing and the roll bearing seat, and the output signal is connected to the dynamic roll gap adjustment system;

[0045] Among them, the reducing mill group and the sizing mill group are connected in series through a tension detection device, and the tension fluctuation is controlled within ±15 kN.

[0046] Furthermore, the roll ring material of the cantilever reducing mill is tungsten carbide, the surface hardness ≥ HRC65, the stroke of the roll axial displacement mechanism ≥ 5 mm, the cooling zone control system includes 8 - 12 independent cooling circuits, the flow control accuracy of each circuit is ±2%, and it is data-linked with the infrared temperature measurement array of the multi-parameter feedback unit.

[0047] Furthermore, the pass system of the four-high sizing mill adopts a three-stand ellipse-round-multi-segment arc configuration, where,

[0048] The width-to-height ratio of the ellipse pass is 1.8 - 2.2, and the roll gap ≥ 0.8 mm;

[0049] The inner arc angle of the round pass is 80° - 150°, and the roll gap ≥ 0.8 mm;

[0050] The roll gap of the multi-segment arc pass ≥ 1 mm, and the pass curve is corrected in real time by the dynamic roll gap adjustment system according to the feedback data of the laser diameter gauge.

[0051] Furthermore, the dynamic roll gap adjustment system includes:

[0052] Worm and worm gear transmission mechanism, mechanically connected to the servo motor through a reduction box, with a reduction ratio of 50:1 - 100:1, and the output shaft is rigidly connected to the roll bearing seat through a spline coupling;

[0053] A hydraulic servo system, including a double-acting hydraulic cylinder and a proportional valve, with a hydraulic pipeline pressure of 20 - 25 mPa, and the end of the piston rod is hinged to the adjusting nut of the worm and worm gear mechanism;

[0054] An embedded control module, integrating a PID controller and a fuzzy logic compensator, is connected in the following ways:

[0055] (i) Receiving rolling force, temperature and dimension data from a multi-parameter feedback unit;

[0056] (ii) Outputting a PWM signal to the servo motor driver;

[0057] (iii) Sending a 4 - 20 mA analog command to the hydraulic proportional valve;

[0058] Among them, the worm and worm gear mechanism and the hydraulic servo system form a dual-redundancy drive, with a response time ≤ 5 ms and a position control accuracy of ±0.001 mm.

[0059] Furthermore, the communication architecture between the multi-parameter feedback unit and the central control system includes:

[0060] The data of the laser diameter gauge is transmitted through optical fiber, and the sampling frequency ≥ 10 kHz;

[0061] The infrared temperature measurement array adopts a distributed I / O module, and the temperature data refresh rate ≥ 1000 Hz;

[0062] The signal of the rolling force sensor is uploaded in real time through the PROFINET IRT protocol after 24-bit AD conversion;

[0063] Among them, the motion control cycle of the central controller ≤ 1 ms, and the synchronization error between the dynamic roll gap adjustment command and the mill speed ≤ 0.1°.

[0064] This production system and method realizes large reduction rolling through a two-stand reducing mill, and realizes high-precision rolling through one or two sizing mills, ensuring the surface and core tissue uniformity of wire rod products; adopting a four-high pass, improving the roundness of the finished wire rod size and avoiding the defect of low roundness of the products produced by the two-high reducing and sizing mill for wire; adopting a four-high pass, improving the accuracy of the finished bar size and avoiding the "near triangle" defect of the products produced by the three-high reducing and sizing mill for bar; adopting a multi-segment arc four-high pass, avoiding the "green line" defect easily produced during multi-high rolling; the unit structure is compact, with fewer stands, saving investment; the mill has high stability, a high single-groove steel passing capacity of the roll ring (single-groove steel passing capacity ≥ 1000 tons), high production stability, and a high mill operation rate; the product production specification range is wide and the product size accuracy is high.

[0065] The beneficial effects of the present invention are as follows:

[0066] (1) Through the PID control algorithm of the dynamic roll gap adjustment system and the feedforward compensation of the rolling force, combined with the real-time monitoring of ±0.01 mm by the laser diameter gauge, the roll gap correction response time is achieved to be ≤5 milliseconds. Compared with the ±0.1 mm accuracy of the traditional two-high / three-high rolling mills, the dimensional fluctuation is reduced by 50%.

[0067] (2) Adopt the multi-segment arc pass design of the four-high sizing mill, and optimize the matching of the inner arc angle of 30° - 60° and the outer arc angle of 15° - 30° to avoid the stress concentration of the traditional oval-round pass.

[0068] (3) Based on the HRC65 hardness of the tungsten carbide roll ring and the ±2% flow accuracy of the cooling zone control system, the rolling speed of high-speed wire rods is increased from 120 m / s to 140 m / s, and the rolling speed of bars is increased from 25 m / s to 35 m / s, and the steel passing capacity per single groove of the roll ring is ≥1000 tons.

[0069] (4) The axial movement mechanism of the cantilever type reducing mill and the cooling gradient control act synergistically to reduce the thermal cracks on the roll surface.

[0070] (5) The fuzzy logic compensation algorithm of the dynamic roll gap adjustment system reduces the rejection rate, combined with the compactness of the four-high mill structure.

[0071] Other advantages, objectives and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. Brief Description of the Drawings

[0072] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in preferred detail below in conjunction with the drawings, where:

[0073] Figure 1 is a schematic diagram of the typical high-speed wire rod process layout;

[0074] Figure 2 is a schematic diagram of the typical special quality steel bar process layout;

[0075] Figure 3 is a schematic diagram of the high-speed wire rod process layout of the present invention;

[0076] Figure 4 is a schematic diagram of the special quality steel bar process layout of the present invention;

[0077] Figure 5 is a schematic diagram of the four-high sizing mill of the present invention;

[0078] Figure 6 is a pass system diagram of the three-stand high-precision rolling mill of the high-speed wire rod production line of the present invention;

[0079] Figure 7 This is the pass system diagram of the three-stand high-precision rolling unit in the special steel bar production line of the present invention;

[0080] Figure 8 This is the pass system diagram of the four-stand high-precision rolling unit in the high-speed wire rod production line of the present invention;

[0081] Figure 9 This is the pass system diagram of the four-stand high-precision rolling unit in the special steel bar production line of the present invention.

[0082] Reference numerals: 1 - heating furnace; 2 - rough rolling unit; 3 - crop flying shear; 4 - intermediate rolling unit; 5 - crop flying shear; 6 - pre-finishing rolling unit; 7 - water cooling device before finishing rolling; 8 - crop flying shear; 91 - eight-stand centralized drive 45° V-type top cross finishing rolling unit; 101 - water cooling device after finishing rolling; 111 - breaking shear before reducing and sizing; 121 - 45° V-type top cross reducing and sizing unit; 131 - water cooling device after reducing and sizing; 141 - pinch roll before coiler; 15 - coiler; 16 - air cooling line and subsequent coiling and collecting device; 92 - three-roll reducing and sizing unit; 102 - water cooling device after reducing and sizing; 112 - multiple-length flying shear; 122 - cooling bed; 132 - cold shear; 142 - transfer and collecting device; 1011 - two-stand 45° top cross cantilever reducing mill; 1021 - one-stand or two-stand four-high sizing mill; 1001 - two-stand horizontal-vertical alternating short stress reducing mill; 1002 - one-stand or two-stand four-high sizing mill; 51 - motor; 52 - transmission shaft between motor and gearbox; 53 - gearbox; 54 - transmission shaft between gearbox and rolling mill; 55 - driving roll; 56 - driven roll. Detailed implementation manners

[0083] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0084] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and cannot be understood as a limitation to the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which do not represent the dimensions of the actual products; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0085] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the accompanying drawings. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the accompanying drawings are only for illustrative purposes and should not be construed as a limitation of the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0086] Please refer to Figures 1 to 5 , which is a high-precision production method for wire rods and bars based on the system.

[0087] Embodiment 1: Φ6.0mm high-speed wire rod coil based on three-stand reducing and sizing

[0088] Refer to Figure 6 and Figure 7 , according to the present invention, the production process sequence includes: the production process sequence includes: roughing mill group, intermediate rolling mill group, 45° top-cross cantilever finishing mill group of pre-finishing mill group, two-stand 45° top-cross cantilever reducing mill + 1 to two-stand four-high sizing mill, water tank and recovery section between units, pinch roll between water tanks, pinch roll before the coiler and large-inclination coiler, air-cooling line and subsequent coiling and collecting device, etc. The implementation scheme of the unit and its pass system is as follows:

[0089] Initial setting stage: Load the preset roll gap curve S0 = f(D, σ), D = 6.0mm, σ is the material deformation resistance at 1050°C (σ = 120MPa), and set the initial roll gap s of the reducing mill 椭圆孔 = 1.0mm, s 圆孔 = 0.8mm, and the s of the sizing mill 多段式孔 = 1.2mm.

[0090] 1) Rolling by the roughing mill group: Use the walking beam type reheating furnace 1 to heat the billet with a cross-sectional size of 165m×165mm to 900°C - 1300°C, and roll it through the six-stand roughing mill group. After rolling by the roughing mill group 2, the diameter of the rolled piece is 78mm, the running speed of the rolled piece is 0.67m / s, guides are provided before and after each rolling mill, a flying shear is provided after the roughing mill group, the average compression ratio of the pass deformation during the rolling process is 1.342, and the rolling temperature of the roughing mill group is 900°C - 1150°C;

[0091] 2) Medium rolling mill train rolling: The rolled piece after being rolled by the rough rolling mill train and sheared by the flying shear in step 1) is rolled by a six-stand medium rolling mill train. After being rolled by the medium rolling mill train 4, the diameter of the rolled piece is 35 mm, the running speed of the rolled piece is 3.32 m / s, guide devices are provided before and after each rolling mill, a flying shear is provided after the medium rolling mill train, the average reduction ratio of passes during the rolling process is 1.306, and the rolling temperature of the medium rolling mill train is 900 °C to 1100 °C;

[0092] 3) Pre-finishing rolling mill train rolling: The rolled piece after being rolled by the medium rolling mill train and sheared by the flying shear in step 2) is rolled by a six-stand pre-finishing rolling mill train. Among them, the 13# and 14# rolling mills are short stress line rolling mills, loopers are equipped in front of the 13# and 14# rolling mills, a water cooling section and a recovery section are equipped behind the 14# rolling mill, the 15# - 18# rolling mills are horizontal-vertical cantilever rolling mills or 45° top-intersecting cantilever rolling mills. When the rolling mill is a horizontal-vertical cantilever rolling mill, a looper is equipped in front of each rolling mill. When the rolling mill is a 45° top-intersecting cantilever rolling mill, a looper is equipped in front of the 15# rolling mill, and micro-tension rolling is adopted between the remaining stands. After being rolled by the pre-finishing rolling mill train 6, it is cooled by the water cooling device 7 before finishing rolling. The diameter of the rolled piece is 17.8 mm, the running speed of the rolled piece is 12.83 m / s, guide devices are provided before and after each rolling mill, a crop flying shear 8 is provided after the pre-finishing rolling mill train 6 for shearing the tail end of the rolled piece, the average reduction ratio of passes during the rolling process is 1.253, and the rolling temperature of the pre-finishing rolling mill train is 850 °C to 1050 °C;

[0093] 4) Cooling and recovery between pre-finishing rolling mill trains and after pre-finishing rolling: The rolled pieces after being rolled by the 14# stand and the 18# rolling mill of the pre-finishing rolling mill train in step 3) are subjected to post-pre-finishing controlled cooling and recovery to reduce the core-surface temperature difference, and the maximum cooling capacity of a single water tank is 250 °C; the core-surface temperature difference ≤ 30 °C;

[0094] 5) Finishing rolling mill train rolling: The rolled piece after being rolled by the pre-finishing rolling mill train and sheared by the flying shear in step 4) is rolled by an eight-pass 45° top-intersecting finishing rolling mill train. When rolling, the pass system is an oval-round pass system. After being rolled by the eight-stand centralized drive type 45° V-type top-intersecting finishing rolling mill train 91, the diameter of the rolled piece is 7.2 mm, and the running speed of the rolled piece after being rolled by the finishing rolling mill train is 78.42 m / s; guide devices are provided before and after each rolling mill, the average reduction ratio of passes during the rolling process is 1.254, and the deformation temperature is 750 °C to 900 °C;

[0095] Dynamic adjustment stage:

[0096] The size deviation Δd of the rolled piece is collected in real time (the accuracy of the laser diameter gauge is ±0.01 mm), and when |Δd| ≥ 0.05 mm, roll gap compensation is triggered The compensation accuracy is ±0.001 mm.

[0097] Feedforward compensation formula

[0098] 6) Post-finishing cooling and recovery: The rolled piece after being rolled by the finishing mill in step 5) is subjected to post-finishing controlled cooling and recovery to reduce the temperature difference between the core and the surface. The maximum cooling capacity of a single water tank is about 200 °C;

[0099] 7) Rolling by the high-precision reducing and sizing mill: After the rolled piece is cut off by the front pinch shear 111 before reducing and sizing, the rolled piece is rolled by the high-precision reducing and sizing mill in three passes. The pass system during rolling is an oval-round hole-multi-segment arc pass system. Guides are provided before and after each rolling mill. The diameters after rolling by the two-stand 45° top-cross cantilever reducing mill 1011 and the one-stand four-high sizing mill 1021 are 6.08 mm. The average pass deformation compression ratio during rolling is 1.119, of which the average deformation compression ratio of the first two reducing mill stands is 1.157, and the deformation compression ratio of the last four-high sizing mill is 1.047. The deformation temperature is 750 °C to 900 °C. The running speed of the rolled piece after being rolled by the reducing and sizing mill is 110 m / s; The two stands are arranged alternately at 45° / 135°, and the included angle between the centerlines is 90°±2°; The data of the laser diameter gauge is transmitted through optical fiber, the sampling frequency ≥10 kHz, and the delay ≤1 ms.

[0100] (1) The elliptical hole structure parameters of the reducing mill include the pass width Bk 椭圆孔 , the pass height Hk 椭圆孔 , the inner arc radius r of the pass 1椭圆孔 , the outer arc radius r of the pass 2椭圆孔 , the pass roll gap s 椭圆孔 , and 1.8 ≤ Bk 椭圆孔 / Hk 椭圆孔 ≤ 2.2, s 椭圆孔 ≥ 0.8 mm;

[0101] (2) The round hole structure parameters of the reducing mill include the pass width Bk 圆孔 , the pass height Hk 圆孔 , the inner arc radius r of the pass 1圆孔 , the inner arc angle α 圆孔 , the inner arc tangent L 1圆孔 , the outer arc radius r of the pass 2圆孔 , the pass roll gap s 圆孔 , and 1.01 ≤ Bk 圆孔 / Hk 圆孔 ≤ 1.15, 80° ≤ α 圆孔 ≤ 150°, s 圆孔 ≥ 0.8 mm;

[0102] (3) The multi-segment arc pass structure parameters of the sizing mill include the pass width Bk 多段式孔 , the pass height Hk 多段式孔 , the inner arc r of the pass 1多段式孔 , the inner arc angle α 1多段式孔 , the inner arc r of the pass2多段式孔 , the inner arc angle α 2多段式孔 , the inner arc tangent L 1多段式孔 , the outer arc r of the pass 2多段式孔 , the pass roll gap s 多段式孔 , and 30° ≤ α 1多段式孔 ≤ 60°, 15° ≤ α 2多段式孔 ≤ 30°, s 多段式孔 ≥ 1mm, 1 ≤ r 1多段式孔 / r 2多段式孔 ≤ 3.

[0103] 8) Post-cooling and recovery of the high-precision reducing and sizing mill: The rolled piece after being rolled by the high-precision reducing and sizing mill in step 7) is subjected to post-control cooling and recovery of the reducing and sizing mill to achieve the control of the structure after rolling, providing a basis for the structure transformation of the subsequent air-cooling line. The maximum cooling capacity of a single water tank is about 200 °C;

[0104] Roll profile correction program:

[0105] It is started after every 300 pieces are rolled. The axial displacement δ = 0.15 mm, and the cooling water flow gradient ΔQ = 8% (the flow at both ends of the roll body increases by 8% compared with the middle).

[0106] 9) Coiling by the coiler: The rolled piece after being post-cooled by the high-precision reducing and sizing mill in step 8) is coiled by the coiler. A pinch roll is arranged in front of the coiler, and a micro-tension control is adopted between the pinch roll 141 in front of the coiler and the coiler 15 to achieve stable coiling. The coiling temperature is 700 °C to 950 °C;

[0107] 10) Cooling on the air-cooling line: The coiled coil after being coiled by the coiler in step 9) is subjected to controlled cooling on the air-cooling line. The controlled cooling on the air-cooling line is divided into three methods: air cooling, air blast cooling, and slow cooling. The speed range of the roller table on the air-cooling line is 0.1 to 3 m / s, the cooling speed of the rolled piece on the air-cooling line is 0.1 °C / s to 30 °C / s, and the temperature of the rolled piece reaching the coil collecting station after being cooled on the air-cooling line is 300 °C to 550 °C;

[0108] 11) Coil collecting: The rolled piece after being cooled on the air-cooling line in step 9) is collected by a vertical coil core rack or a double-core rod, and then cooled on the PF line, bundled, tagged, weighed, and unloaded. The finished product size accuracy is ±0.05 mm, and the ovality is ≤ 0.05.

[0109] The motor 51 is connected to the gearbox 53 through the transmission shaft 52 between the motor and the gearbox, and the gearbox 53 drives the driving roll 55 and the driven roll 56 through the transmission shaft 54 between the gearbox and the rolling mill.

[0110] Example 2: Φ6.0 mm high-speed wire rod coil based on a four-stand reducing and sizing mill

[0111] Refer to Figure 8 and Figure 9, according to the present invention, the production process sequence includes: the production process sequence includes: roughing mill train, intermediate rolling mill train, pre-finishing mill train, 45° top-cross cantilever type finishing mill, two-stand 45° top-cross cantilever type reducing mill + 1 to two-stand four-high sizing mill, water tanks and recovery section between mill trains, pinch rolls between water tanks, pinch roll before the coiler and large-inclination coiler, air cooling line and subsequent coiling and collecting device, etc. The comparative group uses a three-roll reducing and sizing mill for rolling, and the product accuracy is ±0.12 mm. The implementation scheme of the mill train and its pass system is specifically as follows:

[0112] Initial setting stage:

[0113] Load the preset roll gap curve S0 = f(6.0 mm, 115 MPa), and set the reducing mill s 椭圆孔 = 1.1 mm, s 圆孔 = 0.9 mm, and the sizing mill s 多段式孔 = 1.3 mm.

[0114] 1) Rolling by the roughing mill train: Use a walking beam type reheating furnace to heat the billet with a cross-sectional size of 165 m × 165 mm to 900°C to 1300°C, and roll it through a six-stand roughing mill train. After rolling, the diameter of the rolled piece is 78 mm, the running speed of the rolled piece is 0.67 m / s, guides are provided before and after each rolling mill, a flying shear is provided after the roughing mill train, the average reduction ratio of pass deformation during the rolling process is 1.342, and the rolling temperature of the roughing mill train is 900°C to 1150°C;

[0115] 2) Rolling by the intermediate rolling mill train: Roll the rolled piece obtained by rolling through the roughing mill train in step 1) and cutting the head by the flying shear through a six-stand intermediate rolling mill train. After rolling, the diameter of the rolled piece is 35 mm, the running speed of the rolled piece is 3.32 m / s, guides are provided before and after each rolling mill, a flying shear is provided after the intermediate rolling mill train, the average reduction ratio of pass deformation during the rolling process is 1.306, and the rolling temperature of the intermediate rolling mill train is 900°C to 1100°C;

[0116] 3) Rolling by the pre-finishing mill train: Roll the rolled piece obtained by rolling through the intermediate rolling mill train in step 2) and cutting the tail by the flying shear through a six-stand pre-finishing mill train. Among them, the 13# and 14# rolling mills are short stress line rolling mills, loopers are equipped in front of the 13# and 14# rolling mills, a water cooling section and a recovery section are equipped behind the 14# rolling mill, the 15# to 18# rolling mills are horizontal-vertical cantilever type rolling mills or 45° top-cross cantilever type rolling mills. When the rolling mill is a horizontal-vertical cantilever type rolling mill, a looper is equipped in front of each rolling mill. When the rolling mill is a 45° top-cross cantilever type rolling mill, a looper is equipped in front of the 15# rolling mill, and micro-tension rolling is adopted between the remaining stands. After rolling by the pre-finishing mill train, the diameter of the rolled piece is 17.8 mm, the running speed of the rolled piece is 12.83 m / s, guides are provided before and after each rolling mill, a flying shear is provided after the pre-finishing mill train, the average reduction ratio of pass deformation during the rolling process is 1.253, and the rolling temperature of the pre-finishing mill train is 850°C to 1050°C;

[0117] 4) Post-precision rolling mill cooling and recovery: After the rolled pieces are rolled by the 14th stand of the post-precision rolling mill group and the 18th rolling mill in step 3), post-precision rolling controlled cooling and recovery are carried out to reduce the temperature difference between the core and the surface. The maximum cooling capacity of a single water tank is about 250 °C;

[0118] 5) Precision rolling mill rolling: The rolled pieces that have been rolled by the post-precision rolling mill group and have their tails sheared by the flying shear in step 4) are rolled by an 8-pass 45° top cross precision rolling mill group. During rolling, the pass system is an oval-round pass system. After being rolled by the precision rolling mill group, the diameter of the rolled piece is 7.2 mm, and the running speed of the rolled piece after being rolled by the precision rolling mill group is 78.42 m / s; There are guides before and after each rolling mill. During the rolling process, the average pass deformation compression ratio is 1.254, and the deformation temperature is 750 °C - 900 °C;

[0119] 6) Precision rolling post-cooling and recovery: After the rolled pieces are rolled by the precision rolling mill group in step 5), precision rolling controlled cooling and recovery are carried out to reduce the temperature difference between the core and the surface. The maximum cooling capacity of a single water tank is about 200 °C;

[0120] Dynamic adjustment stage:

[0121] Real-time collect the size deviation Δd of the rolled piece (the accuracy of the laser diameter gauge is ±0.01 mm). When |Δd| ≥ 0.05 mm, trigger the roll gap compensation ΔS = 1.0Δd + 0.1∫Δddt, K p = 1.0, K i = 0.1, and the compensation frequency is 1000 Hz.

[0122] 7) High-precision reducing and sizing mill rolling: The rolled pieces that have been cooled after precision rolling in step 6) are rolled by a high-precision reducing and sizing mill group in four passes. During rolling, the pass system is an oval-round-multi-segment arc-multi-segment arc pass system. There are guides before and after each rolling mill. After being rolled by the 45° top cross cantilever type reducing mill 1011 of the second rolling mill stand and the two-stand four-high sizing mill 1021, the diameter is 6.08 mm. During the rolling process, the average pass deformation compression ratio is 1.088, of which the average deformation compression ratio of the first two reducing mill groups is 1.137, and the average deformation compression ratio of the last two four-high sizing mills is 1.042. The deformation temperature is 750 °C - 900 °C. After being rolled by the reducing and sizing mill group, the running speed of the rolled piece is 110 m / s;

[0123] (1) The hole structure parameters of the oval hole of the reducing mill include the hole width Bk 椭圆孔 , the hole height Hk 椭圆孔 , the inner arc radius r of the hole 1椭圆孔 , the outer arc radius r of the hole 2椭圆孔 , the roll gap s of the hole 椭圆孔 , and 1.8 ≤ Bk 椭圆孔 / Hk 椭圆孔≤2.2, s 椭圆孔 ≥0.8 mm;

[0124] (2) The structural parameters of the round hole of the reducing mill include the groove width Bk 圆孔 ), the groove height Hk 圆孔 , the inner arc radius r1r 1圆孔 , the inner arc angle α 圆孔 , the inner arc tangent L 1圆孔 , the outer arc radius r of the groove 2圆孔 , the roll gap s of the groove 圆孔 , and 1.01 ≤ Bk 圆孔 / Hk 圆孔 ≤1.15, 80° ≤ α 圆孔 ≤150°, s 圆孔 ≥0.8 mm;

[0125] (3) The structural parameters of the multi-segment arc-shaped groove of the sizing mill include the groove width Bk 多段式孔 , the groove height Hk 多段式孔 , the inner arc r of the groove 1多段式孔 , the inner arc angle α 1多段式孔 , the inner arc r of the groove 2多段式孔 , the inner arc angle α 2多段式孔 , the inner arc tangent L 1多段式孔 , the outer arc r of the groove 2多段式孔 , the roll gap s of the groove 多段式孔 , and 30° ≤ α 1多段式孔 ≤60°, 15° ≤ α 2多段式孔 ≤30°, s 多段式孔 ≥1 mm, 1 ≤ r 1多段式孔 / r 2多段式孔 ≤3.

[0126] Calculation formula for the groove angle θ outer = 15.25°;

[0127] Verification of angle tolerance: Measured angle deviation ≤ ±0.3°.

[0128] (8) Post-cooling and recovery of the high-precision reducing-sizing mill: The rolled piece after being rolled by the high-precision reducing-sizing mill in step (7) is subjected to post-control cooling and recovery of the reducing-sizing mill to achieve control of the post-rolling structure and provide a basis for the structure transformation of the subsequent air-cooling line. The maximum cooling capacity of a single water tank is about 200 °C;

[0129] Roll profile correction program: Start after rolling 250 pieces, δ = 0.2 mm, ΔQ = 10%;

[0130] 9) Coiling of wire by the wire coiler: The rolled piece cooled by the high-precision reducing and sizing mill in step 8) is coiled by the wire coiler. A pinch roll is arranged in front of the wire coiler. Micro-tension control is adopted between the pinch roll in front of the wire coiler and the wire coiler to achieve stable wire coiling. The wire coiling temperature is 700°C to 950°C;

[0131] 10) Cooling on the air-cooling line: The coiled coil after being coiled by the wire coiler in step 9) is controlled and cooled on the air-cooling line. The controlled cooling on the air-cooling line is divided into three methods: air cooling, air blast cooling and slow cooling. The speed range of the roller table on the air-cooling line is 0.1 to 3 m / s, and the cooling speed of the rolled piece on the air-cooling line is 0.1°C / s to 30°C / s. The temperature of the rolled piece reaching the coil collecting station after being cooled by the air-cooling line is 300°C to 550°C;

[0132] 11) Coil collecting: The rolled piece cooled by the air-cooling line in step 10) is collected by a vertical coil core holder or a double-core bar coil collector, and then cooled on the PF line, bundled, tagged, weighed and uncoiled. The rolling speed is 140 m / s, and the response time of the hydraulic servo system is ≤3 ms; The steel passing capacity of a single groove of the tungsten carbide roll ring is ≥1200 tons, and the service life is increased by 45%.

[0133] The motor 51 is connected to the gearbox 53 through the transmission shaft 52 between the motor and the gearbox, and the gearbox 53 drives the driving roll 55 and the driven roll 56 through the transmission shaft 54 between the gearbox and the rolling mill.

[0134] Example 3: Special quality steel bar of Φ20.0mm based on three-stand reducing and sizing

[0135] Refer to Figure 6 and Figure 7 , according to the present invention, the production process sequence includes: roughing mill group, intermediate rolling mill group, finishing mill group, two-stand short stress line type reducing mill + 1 to two-stand four-high sizing mill, water tank and recovery section between the mills, pinch roll between the water tanks, flying shear for multiple lengths, cooling bed and subsequent collecting device, etc. The implementation scheme of the mill group and its pass system is as follows:

[0136] Initial setting stage:

[0137] Reduction ratio

[0138] When the reduction ratio is within the range of 1.10 to 1.35, the rolling force fluctuation ≤±5%;

[0139] Load S0 = f(20.0mm, 150MPa), set the reducing mill s 椭圆孔 = 2.0mm, s 圆孔 = 1.5mm, and the sizing mill s 多段式孔 = 2.5mm.

[0140] 1) Rough rolling by roughing mill train: A walking beam reheating furnace is used to heat steel billets with a cross-sectional size of 170m×170mm to 900°C - 1300°C, and they are rolled by a six-stand roughing mill train. After being rolled by the roughing mill train 2, the diameter of the rolled piece is 80.0mm, the running speed of the rolled piece is 0.95m / s, guides are provided before and after each rolling mill, a flying shear is provided after the roughing mill train, the average reduction ratio of passes during the rolling process is 1.344, and the rolling temperature of the roughing mill train is 900°C - 1150°C;

[0141] 2) Medium rolling by medium rolling mill train: The rolled piece obtained by rolling in the roughing mill train in step 1 and having its head cut by the flying shear is rolled by a six-stand medium rolling mill train. After rolling, the diameter of the rolled piece is 38.0mm, the running speed of the rolled piece is 4.19m / s, guides are provided before and after each rolling mill, a flying shear is provided after the medium rolling mill train, the average reduction ratio of passes during the rolling process is 1.282, and the rolling temperature of the medium rolling mill train is 900°C - 1100°C;

[0142] 3) Pre-finishing cooling and recovery: The rolled piece after being rolled in the medium rolling mill train in step 2 is subjected to pre-finishing controlled cooling and recovery to reduce the core-surface temperature difference, and the maximum cooling capacity of a single water tank is about 250°C;

[0143] 4) Rolling by finishing mill train: The rolled piece after being subjected to pre-finishing controlled cooling and having its tail cut by the flying shear in step 3 is rolled by a four-stand finishing mill train. A loop is equipped in front of each rolling mill, and tension-free rolling is adopted between the stands. After being rolled by the short stress line type reducing mill 1001 and the four-high sizing mill 1002, the diameter of the rolled piece is 25.0mm, the running speed of the rolled piece is 9.69m / s, guides are provided before and after each rolling mill, the average reduction ratio of passes during the rolling process is 1.233, and the rolling temperature of the finishing mill train is 800°C - 1050°C;

[0144] 5) Post-finishing cooling and recovery: The rolled piece after being rolled in the finishing mill train in step 4 is subjected to post-finishing controlled cooling and recovery to reduce the core-surface temperature difference, and the maximum cooling capacity of a single water tank is about 200°C;

[0145] 6) Rolling by high-precision reducing and sizing mill train: The rolled piece after being subjected to post-finishing cooling and having its head and tail cut by the flying shear in step 5 is rolled by a three-pass high-precision reducing and sizing mill train. The pass system during rolling is an oval-round-multi-segment arc pass system, guides are provided before and after each rolling mill, loops are equipped in front of the short stress line type reducing mill and the four-high sizing mill, tension-free rolling is adopted between the stands, the diameter of the rolled piece after rolling is 20.27mm, the average reduction ratio of passes during the rolling process is 1.150, among which the average reduction ratio of the first two reducing mill stands is 1.205, and the reduction ratio of the last four-high sizing mill is 1.047, the deformation temperature is 750°C - 900°C, and the running speed of the rolled piece after being rolled by the reducing and sizing mill train is 14.7m / s;

[0146] (1) The structural parameters of the elliptical hole of the reducing mill include the hole width Bk 椭圆孔 , the hole height Hk 椭圆孔 , the inner arc radius r of the hole 1椭圆孔 , the outer arc radius r of the hole 2椭圆孔 , the roll gap s of the hole 椭圆孔 , and 1.8 ≤ Bk 椭圆孔 / Hk 椭圆孔 ≤ 2.2, s 椭圆孔 ≥ 0.8 mm;

[0147] (2) The structural parameters of the round hole of the reducing mill include the hole width Bk 圆孔 , the hole height Hk 圆孔 , the inner arc radius r of the hole 1圆孔 , the inner arc angle α 圆孔 , the inner arc tangent L 1圆孔 , the outer arc radius r of the hole 2圆孔 , the roll gap s of the hole 圆孔 , and 1.01 ≤ Bk 圆孔 / Hk 圆孔 ≤ 1.15, 80° ≤ α 圆孔 ≤ 150°, s 圆孔 ≥ 0.8 mm;

[0148] (3) The structural parameters of the multi-segment arc-shaped pass of the sizing mill include the pass width Bk 多段式孔 , the pass height Hk 多段式孔 , the inner arc r of the pass 1多段式孔 , the inner arc angle α 1多段式孔 , the inner arc r of the pass 2多段式孔 , the inner arc angle α 2多段式孔 , the inner arc tangent L 1多段式孔 , the outer arc r of the pass 2多段式孔 , the roll gap s of the pass 多段式孔 , and 30° ≤ α 1多段式孔 ≤ 60°, 15° ≤ α 2多段式孔 ≤ 30°, s 多段式孔 ≥ 1 mm, 1 ≤ r 1多段式孔 / r 2多段式孔 ≤ 3.

[0149] Dynamic adjustment stage:

[0150] The size deviation Δd of the rolled piece is collected in real time (the accuracy of the laser diameter gauge is ±0.01 mm). When |Δd| ≥ 0.05 mm, the roll gap compensation ΔS = 0.7Δd + 0.03∫Δd dt, K p = 0.7, K i = 0.03, and the response time ≤ 10 ms.

[0151] When the temperature difference between the core and the surface is 30°C, the roll gap compensation amount β = 0.09 mm;

[0152] The rolling force sensor signal is converted by a 24-bit AD converter, and the upload period of PROFINET is ≤1 ms;

[0153] 7) Post-cooling and recovery of the high-precision sizing-reducing mill: The rolled piece after being rolled by the high-precision sizing-reducing mill in step 7) is subjected to post-control cooling and recovery of the sizing-reducing mill to achieve post-rolling microstructure control, providing a microstructure transformation basis for the subsequent air-cooling line microstructure transformation. The maximum cooling capacity of a single water tank is about 200 °C;

[0154] 8) Cooling on the cooling bed: The rolled piece braked by the apron in step 7) is air-cooled on the cooling bed. Among them, the temperature of the rolled piece on the cooling bed is in two temperature ranges, and the temperature of the rolled piece after being cooled by the cooling bed 122 is 650 °C - 920 °C;

[0155] Roll profile correction program: Start after rolling 400 pieces, δ = 0.3 mm, ΔQ = 15%;

[0156] 9) Strapping and collecting: After the rolled piece air-cooled on the cooling bed in step 8) is sheared by the flying shear 112 for multiple lengths, the rolled piece enters the cooling bed 122 for cooling, and after passing through the cross inspection bench, it is counted, strapped, weighed and collected. The dimensional accuracy is ±0.06 mm, there is no "near triangle" defect, and the production cost is reduced by 12%.

[0157] The motor 51 is connected to the gearbox 53 through the transmission shaft 52 between the motor and the gearbox, and the gearbox 53 drives the driving roll 55 and the driven roll 56 through the transmission shaft 54 between the gearbox and the rolling mill.

[0158] Example 4: Special quality steel bar of Φ20.0 mm based on four-stand sizing-reducing

[0159] Refer to Figure 8 and Figure 9 , according to the present invention, the production process sequence includes: roughing mill, intermediate rolling mill, finishing mill, two-stand short-stress-line reducing mill + 1 - two-stand four-high sizing mill, inter-stand water tank and recovery section, pinch roll between water tanks, flying shear for multiple lengths, cooling bed and subsequent collecting device, etc.

[0160] Dual redundant drive mechanism: The worm and worm gear mechanism (reduction ratio 80:1) is connected in parallel with the hydraulic servo system (pressure 22 MPa), the response time is ≤5 ms; the rolling force fluctuation suppression rate is ≥90%;

[0161] The implementation scheme of this unit and its pass system is as follows:

[0162] Initial setting stage:

[0163] Load S0 = f(20.0 mm, 160 MPa), set the reducing mill s 椭圆孔 = 2.2 mm, s 圆孔 = 1.8 mm, sizing mill s多段式孔 = 2.8 mm.

[0164] 1) Rough rolling by roughing mill group: The billet with a cross-sectional size of 170 m×170 mm is heated to 900°C - 1300°C by a walking beam reheating furnace and rolled by a six-stand roughing mill group. After rolling, the diameter of the rolled piece is 80.0 mm, the running speed of the rolled piece is 0.95 m / s, guiding devices are installed before and after each rolling mill, a flying shear is installed after the roughing mill group, the average reduction ratio of pass deformation during the rolling process is 1.344, and the rolling temperature of the roughing mill group is 900°C - 1150°C;

[0165] 2) Medium rolling by medium rolling mill group: The rolled piece after being rolled by the roughing mill group and having its head cut off by the flying shear in step 1) is rolled by a six-stand medium rolling mill group. After rolling, the diameter of the rolled piece is 38.0 mm, the running speed of the rolled piece is 4.19 m / s, guiding devices are installed before and after each rolling mill, a flying shear is installed after the medium rolling mill group, the average reduction ratio of pass deformation during the rolling process is 1.282, and the rolling temperature of the medium rolling mill group is 900°C - 1100°C;

[0166] 3) Cooling and recovery before finishing rolling: The rolled piece after being rolled by the medium rolling mill group in step 2) is subjected to controlled cooling and recovery before finishing rolling to reduce the temperature difference between the core and the surface. The maximum cooling capacity of a single water tank is approximately 250°C;

[0167] 4) Rolling by finishing mill group: The rolled piece after being subjected to controlled cooling before finishing rolling and having its tail cut off by the flying shear in step 3) is rolled by a four-stand finishing mill group. A loop is equipped in front of each rolling mill, and tensionless rolling is adopted between the stands. After rolling by the finishing mill group, the diameter of the rolled piece is 25.0 mm, the running speed of the rolled piece is 9.69 m / s, guiding devices are installed before and after each rolling mill, the average reduction ratio of pass deformation during the rolling process is 1.233, and the rolling temperature of the finishing mill group is 800°C - 1050°C;

[0168] 5) Cooling and recovery after finishing rolling: The rolled piece after being rolled by the finishing mill group in step 4) is subjected to controlled cooling and recovery after finishing rolling to reduce the temperature difference between the core and the surface. The maximum cooling capacity of a single water tank is approximately 200°C;

[0169] 6) High-precision reducing and sizing mill rolling: The rolled piece after being cooled and having its head and tail sheared by flying shear in step 5) is subjected to four-pass high-precision reducing and sizing mill rolling. During rolling, the pass system is an oval-round-multi-segment arc-multi-segment arc pass system. Guide devices are provided before and after each rolling mill. For the short stress line reducing mill, a loop is equipped in front of each rolling mill, and tension-free rolling is adopted between stands. For the four-high sizing mill, a loop is equipped in front of the first sizing mill, and tension-free rolling is adopted between the reducing mill and the sizing mill, and micro-tension rolling is adopted between the two sizing mills. After rolling by the two-stand short stress type reducing mill 1001 and the two-stand four-high sizing mill 1002, the diameter is 20.27 mm. The average pass deformation compression ratio during rolling is 1.111, among which the average deformation compression ratio of the first two reducing mill stands is 1.184, and the deformation compression ratio of the last four-high sizing mill is 1.041. The deformation temperature is 750 °C to 900 °C, and the running speed of the rolled piece after being rolled by the reducing and sizing mill is 14.7 m / s;

[0170] (1) The hole structure parameters of the oval hole of the reducing mill include the hole width Bk 椭圆孔 , the hole height Hk 椭圆孔 , the inner arc radius r 1椭圆孔 , the outer arc radius r 2椭圆孔 , the roll gap s 椭圆孔 , and 1.8 ≤ Bk 椭圆孔 / Hk 椭圆孔 ≤ 2.2, s 椭圆孔 ≥ 0.8 mm;

[0171] (2) The hole structure parameters of the round hole of the reducing mill include the hole width Bk 圆孔 , the hole height Hk 圆孔 , the inner arc radius r 1圆孔 the inner arc angle α 圆孔 , the inner arc tangent L 1圆孔 , the outer arc radius r 2圆孔 , the roll gap s 圆孔 , and 1.01 ≤ Bk 圆孔 / Hk 圆孔 ≤ 1.15, 80° ≤ α 圆孔 ≤ 150°, s 圆孔 ≥ 0.8 mm;

[0172] (3) The multi-segment arc pass structure parameters of the sizing mill include the hole width Bk 多段式孔 , the hole height Hk 多段式孔 , the inner arc r 1多段式孔 , the inner arc angle α 1多段式孔 , the inner arc r 2多段式孔 , the inner arc angle α 2多段式孔 , the inner arc tangent L 1多段式孔 , the outer arc r 2多段式孔 , the roll gap s多段式孔 and 30° ≤ α 1多段式孔 ≤ 60°, 15° ≤ α 2多段式孔 ≤ 30°, s 多段式孔 ≥ 1 mm, 1 ≤ r 1多段式孔 / r 2多段式孔 ≤ 3.

[0173] Dynamic adjustment stage:

[0174] Real-time collect the size deviation Δd of the rolled piece (the accuracy of the laser diameter gauge is ±0.01 mm). When |Δd| ≥ 0.05 mm, trigger the roll gap compensation ΔS = 1.2Δd + 0.08∫Δddt, K p = 1.2K i = 0.08, and the rolling force feedforward compensation α = 1.2.

[0175] 7) Post-cooling and recovery of the high-precision reducing and sizing mill: Conduct post-control cooling and recovery on the rolled piece after rolling by the high-precision reducing and sizing mill in step 7) to achieve post-rolling microstructure control, providing a microstructure transformation basis for the subsequent air-cooling line microstructure transformation. The maximum cooling capacity of a single water tank is approximately 200 °C;

[0176] 8) Cooling on the cooling bed: Conduct air cooling on the rolled piece braked by the apron in step 7). Among them, the temperature of the rolled piece on the cooling bed is in two temperature ranges, 920 °C to 650 °C;

[0177] Roll profile correction program: Start every 350 rolls are made, δ = 0.25 mm, ΔQ = 12%;

[0178] 9) Strapping and collecting: Conduct cold shearing and sizing on the rolled piece after air cooling on the cooling bed in step 8). After passing through the cross inspection bench, count, strap, weigh, and collect. After cold shearing and sizing at 132, count and strap through the cross and collecting device 142. The dimensional accuracy is ±0.04 mm, the rolling speed is 20 m / s, and the roll ring life is increased by 35%. Cooling zone control reduces energy consumption by 12%, real-time communication reduces the scrap rate by 3%, and the comprehensive cost is reduced by 12%;

[0179] The motor 51 is connected to the gearbox 53 through the transmission shaft 52 between the motor and the gearbox. The gearbox 53 drives the driving roll 55 and the driven roll 56 through the transmission shaft 54 between the gearbox and the rolling mill.

[0180] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A high-precision production method for wire rod, characterized in that: It includes the following steps: Initial setting stage: Load the preset roll gap curve S0 = f(D, σ) according to the blank specifications, and set the single-pass compression ratio range of the reducing rolling mill set to 1.10 - 1.35; the single-pass compression ratio range of the four-high sizing rolling mill set to 1.001 - 1.10; where D is the finished diameter and σ is the material deformation resistance, and the loading algorithm includes: wherein, K1 = 120 to 180 MPa·mm 2 , K2 = 0.3 to 0.8 mm; Dynamic adjustment stage: Real-time collect the dimensional deviation Δd of the rolled piece and the temperature change ΔT. When |Δd| ≥ 0.05 mm, trigger roll gap compensation: where K p is the proportionality coefficient, K p = 0.5 to 1.5; K i is the integral coefficient, K i = 0.01 to 0.1, K d is the differential coefficient, K d = 0.05 to 0.2; β is the temperature coupling correction term; Roll profile correction stage: Perform axial movement calculation every 100 - 400 rolled pieces: And synchronously adjust the cooling water flow rate gradient ΔQ = 2 - 15%, where N is the cumulative number of rolled pieces.

2. The high-precision production method of a kind of wire rod according to claim 1, characterized in that: The dynamic adjustment stage also includes a rolling force feedforward compensation algorithm, and the stiffness K of the four-roll sizing mill stiffness ≥ 150 t / mm, and the compensation response time ≤ 5 ms: Where α = 1.01 - 1.35 is the material flow stress correction factor.

3. The high-precision production method of a wire rod according to claim 1, characterized in that: The temperature coupling correction term β is calculated by the temperature-roll gap coupling control algorithm, specifically: β = ΔT × 0.003 mm / °C Where the real-time calculation of the temperature compensation coefficient β is based on the infrared temperature measurement array data, the temperature resolution is ±2 °C, and the data sampling frequency ≥ 2000 Hz.

4. The high-precision production method of a wire rod according to claim 1, characterized in that: The single-pass compression ratio of the reducing rolling mill set is dynamically adjusted by the control algorithm, where: Compression ratio of the reducing rolling mill set: Compression ratio of the four-high sizing rolling mill: Among them, D input is the diameter of the rolled piece at the inlet of the reducing mill train, D output is the target diameter of the rolled piece at the outlet of the reducing mill train, D input-s is the diameter of the rolled piece at the inlet of the four-high sizing mill, D final is the diameter of the final finished rolled piece.

5. The high-precision production method of a kind of wire rod according to claim 1, characterized in that: The pass optimization algorithm of the four-high sizing rolling mill includes: Calculate the inner arc angle of the multi-segment arc pass: Outer arc angle: where D final is the finished product diameter in mm, and the angle calculation error ≤ ±0.5°.

6. A wire rod and bar reducing and sizing rolling system, characterized in that: Includes: Reducing rolling mill set, including a cantilever type reducing rolling mill or a short stress line type reducing rolling mill, with adjacent stands arranged alternately and stiffness ≥ 100 t / mm, and the roll axis of the reducing rolling mill set is horizontal or vertical to the rolling line; Four-high sizing rolling mill set, configured in one of the following two forms: (a) Single-stand four-high sizing rolling mill, with the roll axis horizontal or vertical to the rolling line, and the roll surface hardness ≥ HRC68; (b) Double-stand four-high sizing rolling mill, with adjacent stands arranged alternately at 45° and 135°, and the center line included angle is 90° ± 1°; Dynamic roll gap adjustment system, connected to the roll bearing seats of the reducing rolling mill set and the sizing rolling mill set through a mechanical coupling method, for real-time regulating the roll gap size; Multi-parameter feedback unit, including: Laser diameter gauge, installed at the outlet of the reducing rolling mill set and the outlet of the sizing rolling mill set, and signal-connected to the dynamic roll gap adjustment system; Infrared temperature measurement array, set at the inlet and outlet of each rolling mill, and communicating with the central controller through the PROFINET protocol; Rolling force sensor, integrated between the rolling mill housing and the roll bearing seat, and the output signal is connected to the dynamic roll gap adjustment system; Wherein, the reducing rolling mill set and the sizing rolling mill set are connected in series through a tension detection device, and the tension fluctuation is controlled within ±15 kN.

7. The wire rod and bar reducing and sizing rolling system according to claim 6, characterized in that: The roll ring material of the cantilever type reducing rolling mill is tungsten carbide, the surface hardness ≥ HRC65, the stroke of the roll axial movement mechanism ≥ 5 mm, the cooling zone control system includes 8 - 12 independent cooling circuits, the flow control accuracy of each circuit is ±2%, and it is linked with the infrared temperature measurement array data of the multi-parameter feedback unit.

8. The wire rod and bar reducing and sizing rolling system according to claim 6, characterized in that: The pass system of the four-high sizing rolling mill adopts a three-stand ellipse-round-multi-segment arc configuration, where, The width-height ratio of the ellipse pass is 1.8 - 2.2, and the roll gap ≥ 0.8 mm; The inner arc angle of the round hole is 80° to 150°, and the roll gap ≥ 0.8 mm; The roll gap of the multi-segment arc pass ≥ 1 mm, and the pass curve is corrected in real time by the dynamic roll gap adjustment system according to the feedback data of the laser diameter gauge.

9. The wire rod and bar reducing and sizing rolling system according to claim 6, wherein: The dynamic roll gap adjustment system includes: A worm and worm gear transmission mechanism, which is mechanically connected to the servo motor through a reduction box, with a reduction ratio of 50:1 to 100:1, and the output shaft is rigidly connected to the roll bearing seat through a spline coupling; A hydraulic servo system, including a double-acting hydraulic cylinder and a proportional valve, with a hydraulic pipeline pressure of 20 to 25 mPa, and the end of the piston rod is hinged to the adjusting nut of the worm and worm gear mechanism; An embedded control module, integrating a PID controller and a fuzzy logic compensator, is connected in the following ways: (i) Receive the rolling force, temperature and dimension data of the multi-parameter feedback unit; (ii) Output a PWM signal to the servo motor driver; (iii) Send a 4 to 20 mA analog command to the hydraulic proportional valve; Among them, the worm and worm gear mechanism and the hydraulic servo system form a dual-redundancy drive, with a response time ≤ 5 ms and a position control accuracy of ±0.001 mm.

10. The wire rod and bar reducing and sizing rolling system according to claim 6, characterized in that: The communication architecture of the multi-parameter feedback unit and the central control system includes: The data of the laser diameter gauge is transmitted through optical fiber, and the sampling frequency ≥ 10 kHz; The infrared temperature measurement array uses a distributed I / O module, and the temperature data refresh rate ≥ 1000 Hz; The signal of the rolling force sensor is uploaded in real time through the PROFINET IRT protocol after 24-bit AD conversion; Among them, the motion control cycle of the central controller ≤ 1 ms, and the synchronization error between the dynamic roll gap adjustment command and the mill speed ≤ 0.1°.

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