A die profile system and production method for 82B high carbon steel wire rod

Abstract

This invention discloses a pass configuration system and production method for 82B high-carbon steel wire rod. The system comprises, sequentially along the mill roller table from the furnace outlet, a roughing mill, a first flying shear, an intermediate mill, a second flying shear, a pre-finishing mill, a first water tank group, a third flying shear, a finishing mill, and a second water tank group. The end of the mill roller table connects to the wire drawing machine and the Stellmore air-cooling line. This invention solves the problem of drawing fracture caused by excessive network cementite in Φ12.0mm~Φ13.0mm 82B high-carbon steel wire rod without modifying the water tanks, fans, flying shears, etc., by optimizing the pass configuration of the pre-finishing and finishing mills, redesigning the pass configuration system, adjusting the stacking coefficient, reducing the rolling temperature and wire drawing temperature, and improving the cooling capacity of the water tanks and the Stellmore air-cooling line. It also effectively improves the dimensional accuracy and rolling speed of the product.

Description

Technical Field

[0001] This invention belongs to the field of metal wire rolling technology, specifically relating to an 82B high carbon steel wire rod die system and production method. Background Technology

[0002] 82B high-carbon steel wire rod typically ranges in size from Φ6.5mm to Φ13.0mm and is mainly used for processing prestressed steel strands. It is widely used in highways, long-span bridges, high-rise buildings, and other engineering projects. The development trend is towards larger sizes, higher stiffness, lower relaxation, corrosion resistance, and heavier coils. Due to the solidification characteristics of 82B steel and small billets, central segregation is prone to occur, forming a network of cementite in the core, which is the main cause of wire breakage during drawing. This network of cementite is especially likely to occur when producing larger 82B wire rods, such as those with diameters of Φ12.0mm to Φ13.0mm. Furthermore, current production methods suffer from limitations such as limited rolling speed, low output, large dimensional fluctuations, and low product precision.

[0003] The existing technology currently has the following defects: (1) 82B wire rod is usually supplied to customers for continuous cold drawing, with a deformation ratio of more than 84%. When rolling large-specification 82B high carbon steel wire rod, more Stelmore fans should be put into operation and the dampers should be 100% open to obtain a large air volume and high air pressure to strongly cool the wire rod. In order to suppress the precipitation of proeutectoid cementite structure, otherwise the wire rod is prone to brittle fracture during cold drawing. Since the air volume of the fans in some similar production lines is relatively small, network cementite is often detected when producing large-specification 82B wire rods such as Φ12.0mm~Φ13.0mm. (2) Before the rolled piece enters the finishing mill, a flying shear head must be used. Due to the limitation of the flying shear equipment capacity, the linear speed of the pre-finishing material must be controlled below 15.8m / s, otherwise the shearing will be unstable. Therefore, the production line speed for Φ12.0mm is usually limited to 38m / s, and the production line speed for Φ12.5mm and Φ13.0mm is usually limited to 34m / s, so the production capacity cannot be fully utilized. (3) The impact force is unstable and the smoothness is poor when the looper between the pre-finishing mills is lifted. Affected by the inertia and response time during the lifting process, the size of the rolled piece is prone to fluctuation. After the finished product is coiled, the size on both sides will be smaller at the 7th to 12th coil position, which cannot fully meet the C-level precision required by the national standard. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a pass profile system and production method for 82B high-carbon steel wire rod. Without modifying process equipment such as water tanks, fans, and flying shears, this invention solves the problem of drawing fracture caused by excessive network cementite in large-diameter 82B high-carbon steel wire rods (Φ12.0mm~Φ13.0mm) due to large-diameter network cementite. This is achieved by optimizing the pass profile configuration of the pre-finishing and finishing mills, redesigning the pass profile system, adjusting the stacking coefficient, reducing rolling and wire drawing temperatures, and improving the cooling capacity of the water tank and the Stellmore air-cooling line. Furthermore, it effectively improves the dimensional accuracy and rolling speed of the products.

[0005] This invention is achieved through the following technical solution:

[0006] A wire rod pass system for 82B high carbon steel includes a heating furnace and a rolling mill table. From the heating furnace outlet along the rolling mill table are sequentially arranged a roughing mill, a first flying shear, an intermediate mill, a second flying shear, a pre-finishing mill, a first water tank group, a third flying shear, a finishing mill, and a second water tank group. The end of the rolling mill table is connected to a wire drawing machine and a Stellmore air-cooling line.

[0007] The roughing mill group has rolling mills 1-6, the intermediate mill group has rolling mills 7-12, the pre-finishing mill group has rolling mills 13-16, and the finishing mill group has rolling mills 17-24; wherein, rolling mills 13, 15, 17, 19, 21, and 23 have elliptical bores, and rolling mills 14, 16, 18, 20, 22, and 24 have round bores.

[0008] Preferably, it also includes a looper, which is arranged between rolling mills No. 13 and No. 14, and between No. 14 and the finishing mill.

[0009] Preferably, a second water tank group is connected after the finishing mill, the second water tank group including four water tanks and four sections of reheating roller conveyor, the reheating roller conveyor being composed of guide grooves and rollers; the end of the reheating roller conveyor is connected to pinch rolls and a spinning machine, the spinning machine being connected to the Stellmore air-cooling line.

[0010] The production method of 82B high-carbon steel wire rod based on the above system, wherein the specification of the 82B high-carbon steel wire rod is Φ12.0mm~Φ13.0mm, includes the following steps:

[0011] Step 1) After the steel billet is heated in the heating furnace, it enters the rolling mill roller table for rolling. After being rolled by the roughing mill, the first flying shear is used to cut off the head and tail. Then it enters the intermediate mill for rolling and the second flying shear is used to cut off the head and tail.

[0012] Step 2) The billet enters the pre-finishing mill, is rolled by mills 13 and 14, passes through mills 15 and 16 without load, and is then cut off at the head and tail by the third flying shear.

[0013] Step 3) The steel billet enters the finishing mill, and the parameters are adjusted according to different finished product specifications as follows:

[0014] When the finished product specification is Φ12.0mm, the No.17 and No.18 rolling mills pass through empty, the elliptical hole of the No.19 rolling mill is set with major axis B=29.31mm and minor axis H=15.84mm, the circular hole of the No.20 rolling mill is set with radius R=9.85mm, and then after being rolled by the No.21-24 rolling mills, it is sent out of the finishing mill group.

[0015] When the finished product specification is Φ12.5mm, the elliptical hole of the No.17 rolling mill is set with a major axis B=32.17mm and a minor axis H=16.29mm, and the circular hole of the No.18 rolling mill is set with a radius R=9.81mm. After being rolled by the No.19-22 rolling mills, the No.23 and No.24 rolling mills pass through empty and are sent out of the finishing mill group.

[0016] When the finished product specification is Φ13.0mm, the elliptical hole of rolling mill No.17 is set with major axis B=34.22mm and minor axis H=16.30mm, and the circular hole of rolling mill No.18 is set with radius R=10.06mm. After rolling by rolling mills No.19-22, rolling mills No.23 and No.24 pass through empty and are sent out of the finishing mill group.

[0017] Step 4) After the steel billet is rolled by the rolling mill roller table, it enters the Stellmore air-cooling line through the wire spinneret to produce the finished product, thus completing the operation.

[0018] Preferably, in step 2), the parameters at the exit of mill No. 14 are adjusted as follows, depending on the different finished product specifications:

[0019] When the finished product specification is Φ12.0mm, the size of the rolled piece at the exit of mill No. 14 is set to Φ23.0mm, and the exit linear velocity is set to 10.9m / s;

[0020] When the finished product specification is Φ12.5mm, the size of the rolled piece at the exit of mill No. 14 is set to Φ24.1mm, and the exit linear velocity is set to 10.0m / s;

[0021] When the finished product specification is Φ13.0mm, the size of the rolled piece at the exit of mill No. 14 is set to Φ25.6mm, and the exit linear velocity is set to 9.5m / s.

[0022] Preferably, in step 2), after the billet exits the No. 14 rolling mill, it is pre-cooled by the first water tank group to ensure that the temperature entering the finishing mill is less than 910℃.

[0023] Preferably, in step 3), the steel sent out of the finishing mill is water-cooled by a second water tank group to ensure that the wire drawing temperature is less than 870°C.

[0024] The beneficial effects of this invention are as follows:

[0025] (1) The Φ12.0mm~Φ13.0mm 82B high-carbon steel wire rod produced using the die system and controlled rolling and cooling method of this invention can completely eliminate network cementite of grade 2.0 or higher. Furthermore, the average tensile strength of the steel is consistently above 1180MPa, the average reduction of area is consistently above 36%, the sorbite content is above 85%, the grain size is finer than grade 7, the aging deviation of the product is reduced, the tensile strength is within 20MPa, and the reduction of area is within 10%. This ensures stable process performance of the Φ12.0mm~Φ13.0mm 82B high-carbon steel wire rod.

[0026] (2) By using the pass system and controlled rolling and cooling method of the present invention, the actual rolling speed of finished products of various specifications can be increased by 2.0 to 4.0 m / s, and the hourly production capacity can be increased by 6% to 8%, as shown in Table 1 below.

[0027] Table 1 Comparison between existing technology and the present invention

[0028]

[0029]

[0030] (3) By adopting the die system and controlled rolling and cooling method of the present invention, the dimensional accuracy of the finished product has been effectively improved, the problem of the size being too small on both sides at the 7th to 12th rings of the head has been solved, the national standard C-level accuracy requirements have been fully met, the number of trimming rings has been reduced, and the yield rate can be increased by 0.4% to 0.6%.

[0031] (4) This invention reduces the linear velocity of the workpiece entering the finishing mill by skipping mills 15 and 16 in the pre-finishing mill unit and adding mills 23 and 24 in the finishing mill unit. By extending the cooling time in the water tank after pre-finishing, the entry temperature into the finishing mill is reduced, thus minimizing the temperature rise of the workpiece during rolling within the finishing mill unit. This method lowers the wire drawing temperature and reduces the heat energy in the core of the workpiece. It also reduces the self-tempering time of the workpiece on the Steyrmo line, preventing the formation of network cementite.

[0032] (5) The 82B high carbon steel wire rod produced by the die system and controlled rolling and cooling method of the present invention can fully meet the customer requirements in terms of quality, while saving the enterprise a lot of technical transformation investment and reducing production costs. Attached Figure Description

[0033] Figure 1 A schematic diagram of the die-cutting system for 82B high-carbon steel wire rod;

[0034] Figure 2 A schematic diagram of the post-processing flow for 82B high-carbon steel finishing rolling.

[0035] Figure 1-2In the middle section: 1-24, Rolling mill; 25, Heating furnace; 26, Roughing mill; 27, First flying shear; 28, Intermediate mill; 29, Second flying shear; 30, Pre-finishing mill; 31, First water tank group; 32, Third flying shear; 33, Finishing mill; 34, Second water tank group; 35, Regenerating roller conveyor; 36, Pinch rolls; 37, Wire drawing machine; 38, Stellmore air-cooling line; 39, Water tank;

[0036] Figure 3 Configure parameters for the Φ12.0mm finishing mill pass system;

[0037] Figure 4 Configure parameters for the Φ12.5mm finishing mill pass system;

[0038] Figure 5 Configure parameters for the Φ13.0mm finishing mill pass system;

[0039] Figure 6 Metallographic diagram of network cementite (scale bar 20μm): A is Φ13.0mm specification 82B high carbon steel wire rod produced by existing technology, and B is Φ13.0mm specification 82B high carbon steel wire rod produced in Example 1. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0041] Example 1

[0042] A type of die profile system for 82B high carbon steel wire rod, such as Figure 1 As shown, the structure includes a heating furnace 25 and a rolling mill roller table. From the outlet of the heating furnace 25, along the rolling mill roller table, there are sequentially arranged a roughing mill group 26, a first flying shear 27, an intermediate mill group 28, a second flying shear 29, a pre-finishing mill group 30, a first water tank group 31, a third flying shear 32, a finishing mill group 33, and a second water tank group 34.

[0043] like Figure 1 As shown, the roughing mill 26 is equipped with mills 1-6, the intermediate mill 28 is equipped with mills 7-12, the pre-finishing mill 30 is equipped with mills 13-16, and the finishing mill 33 is equipped with mills 17-24; wherein, mills 13, 15, 17, 19, 21, and 23 have elliptical bores, and mills 14, 16, 18, 20, 22, and 24 have round bores.

[0044] It also includes loopers, which are arranged between rolling mills 13 and 14, and between rolling mill 14 and finishing mill 33. Their function is to eliminate tension between rolling mills and prevent fluctuations in the dimensions of rolled pieces.

[0045] like Figure 2As shown, a second water tank group 34 is connected after the finishing mill 33. The second water tank group 34 includes four water tanks 39 and four sections of reheating roller conveyor 35. The reheating roller conveyor 35 consists of guide grooves and rollers. Its function is to transport the rolled workpiece and transfer the heat of the core of the workpiece to the surface to prevent uneven surface cooling. The end of the reheating roller conveyor 35 is connected to the pinch roll 36 and the wire spinner 37. The wire spinner 37 is connected to the Stellmore air cooling line 38.

[0046] The flying shears installed between each unit are used to cut the head and tail and to prevent accidental breakage. The water tank group installed before and after the finishing mill 33 can control the temperature of the finishing mill and the temperature of the wire drawing. The wire drawing machine 37 is cooled by the Stellmore air-cooling line 38.

[0047] A method for producing 82B high-carbon steel wire rod with a diameter of Φ12.0mm to Φ13.0mm, the specific steps of which are as follows:

[0048] (1) After the steel billet is heated by the heating furnace 25, it is rolled into the rolling mill roller table. After being rolled by the roughing mill 26, the first flying shear 27 is used to cut off the head and tail. Then it enters the intermediate rolling mill 28 for rolling, and the second flying shear 29 is used to cut off the head and tail.

[0049] (2) The billet enters the pre-finishing mill group 30, and after being rolled by mills 13 and 14, it passes through mills 15 and 16 without running. After exiting mill 14, the billet is pre-cooled by the first water tank group 31 to ensure that the temperature of the billet entering the finishing mill group 33 is less than 910℃. Then, the third flying shear 32 is used to cut the head and tail.

[0050] The parameters at the exit of mill No. 14 are adjusted as follows, depending on the different finished product specifications:

[0051] When the finished product specification is Φ12.0mm, the size of the rolled piece at the exit of mill No. 14 is set to Φ23.0mm, and the exit linear velocity is set to 10.9m / s;

[0052] When the finished product specification is Φ12.5mm, the size of the rolled piece at the exit of mill No. 14 is set to Φ24.1mm, and the exit linear velocity is set to 10.0m / s;

[0053] When the finished product specification is Φ13.0mm, the size of the rolled piece at the exit of mill No. 14 is set to Φ25.6mm, and the exit linear velocity is set to 9.5m / s.

[0054] The feed speed to the finishing mill has been reduced from a maximum of 15.6 m / s in existing technology to below 10.9 m / s. Data from on-site flow meters shows that the flow rate of each water tank in the pre-cooling box (first water tank group 31) has decreased from 94 m³ / s. 3 / h increased to 130m 3 / h, increasing by 38%, and the rolled piece can still be uniformly tempered when it enters the finishing mill.

[0055] The ideal microstructure for SWRH82B high-carbon wire rod is fine pearlite, i.e., sorbite. Before the phase transformation, the austenite should have a large degree of supercooling and a high cooling rate to increase the phase transformation kinetics and avoid the formation of network cementite. After reaching the phase transformation point, the wire rod should be cooled slowly to ensure sufficient transformation time, which is beneficial for increasing the proportion of sorbite in the wire rod. Large-diameter Φ12.0mm~Φ13.0mm 82B steel wire rods have high core heat energy and large heat capacity, resulting in a long self-tempering time on the Steyrmo line. Increased fan airflow is necessary to prevent the formation of network cementite. Since the existing production line fan configurations are generally too small, further increasing the airflow would require investment in fan upgrades. Therefore, a different approach can be taken: reduce the core heat energy of the rolled piece before wire drawing, thus shortening the self-tempering time.

[0056] Theoretically, the lower the austenitizing temperature of high-carbon steel, the less likely the grains are to grow, and the finer the austenite grains become. Therefore, the grain size of austenite before phase transformation can be controlled by controlling the finishing rolling temperature, thereby improving the mechanical properties of high-carbon hard wire steel. Reducing the temperature at the entry mill is a key method for reducing the finishing rolling temperature. For large-diameter 82B wire rod, reducing the entry mill temperature also reduces the core heat energy of the rolled piece.

[0057] By reducing the rolling speed of the workpiece entering the finishing mill, increasing the flow rate of the cooling water tank before the finishing mill, and extending the cooling time, the rolling temperature entering the finishing mill can be reduced. The reduced linear speed of the workpiece entering the finishing mill, combined with the extended tempering time after cooling in the water tank, results in more uniform surface tempering before entering the finishing mill, ensuring the uniformity of the finished product's metallographic structure. Furthermore, reducing the rolling speed of the workpiece entering the finishing mill can solve the problem of speed limitations imposed by the flying shear equipment.

[0058] To ensure the smooth operation of the continuous rolling process, the flow rate of metal through each mill stand of the continuous rolling mill must be kept equal. Therefore, increasing the finished product speed and reducing the rolling speed entering the finishing mill necessitates increasing the cross-sectional area of ​​the rolled piece entering the finishing mill. Thus, a design was adopted that skips mills 15 and 16, while adding mills 23 and 24 to the finishing mill unit. Simultaneously, the two loopers between mills 14 and 16 were eliminated, and the rolling was transferred to the finishing mill unit for micro-tension rolling. This improves the dimensional accuracy of the rolled piece and resolves the issue of smaller dimensions on both sides of the finished product at the 7th to 12th ring position.

[0059] The hole pattern arrangement of the prior art is shown in Table 2 below. The hole pattern code data is designed by Morgan Company of the United States and is public data, so it is not listed here.

[0060] Table 2. Hole configurations for Φ12.0mm~Φ13.0mm specifications in the prior art.

[0061]

[0062] Table 2 Note: N, Q, S, U are codes for elliptical hole types; P, R, T, and finished product are codes for round hole types.

[0063] The pass configurations of the pre-finishing mill 30 and the finishing mill 33 in this embodiment are shown in Table 3 below:

[0064] Table 3. Hole configuration for Φ12.0mm~Φ13.0mm specifications in this embodiment.

[0065]

[0066] Table 3 Note: N, X, S, U are elliptical hole type codes; P, Y, T, and finished product are round hole type codes.

[0067] (3) The billet enters the finishing mill 33, and the parameters are adjusted according to different finished product specifications as follows:

[0068] When the finished product specification is Φ12.0mm, rolling mills 17 and 18 pass through without load, as shown in Table 3. Figure 3 As shown, the elliptical hole X1 of rolling mill No. 19 is set with major axis B = 29.31 mm and minor axis H = 15.84 mm, and the circular hole Y1 of rolling mill No. 20 is set with radius R = 9.85 mm. After being rolled by rolling mills No. 21-24 (the configuration of the pass system is still as shown in Table 2, in the existing technology, in the order of S1, T1, U1, and finished product), it is sent out of finishing mill group 33.

[0069] When the finished product specification is Φ12.5mm, as shown in Table 3, Figure 4 As shown, the elliptical hole X2 of mill No. 17 is set with a major axis B = 32.17 mm and a minor axis H = 16.29 mm, and the circular hole Y2 of mill No. 18 is set with a radius R = 9.81 mm. After being rolled by mills No. 19-22 (the configuration of the pass system is still as shown in Table 2, in the existing technology, in the order of S2, T2, U2, and finished product), mills No. 23 and No. 24 pass through empty and are sent out of finishing mill group 33.

[0070] When the finished product specification is Φ13.0mm, as shown in Table 3, Figure 5 As shown, the elliptical hole X3 of mill No. 17 is set with major axis B = 34.22mm and minor axis H = 16.30mm, and the circular hole Y3 of mill No. 18 is set with radius R = 10.06mm. After being rolled by mills No. 19-22 (the configuration of the pass system is still as shown in Table 2, in the existing technology, in the order of S2, T2, U2, and finished product), mills No. 23 and No. 24 pass through empty and are sent out of finishing mill group 33.

[0071] The steel billets sent out of the finishing mill 33 are water-cooled by the second water tank group 34 to ensure that the wire drawing temperature is less than 870℃.

[0072] (4) After the steel billet is rolled by the rolling mill roller table, it enters the Stellmore air-cooling line 38 through the wire spinner 37. The fan parameters of the Stellmore air-cooling line 38 can be set according to the existing technology, as shown in Table 4 below. Finally, the finished product is made and the operation is completed.

[0073] Table 4 Parameters of 82B high carbon steel wire rod fans with specifications of Φ12.0mm~Φ13.0mm

[0074]

[0075] Table 4 Note: The air volume when the fan is 100% open is 180,000 m³ / h. 3 / h.

[0076] The performance comparison of this embodiment with that of 82B high-carbon steel wire rods with Φ12.0mm, Φ12.5mm, and Φ13.0mm specifications produced by existing technologies is shown in Table 5 below:

[0077] Table 5 Comparison of Performance Tests for 82B High Carbon Steel Wire Rods with Specifications of Φ12.0mm~Φ13.0mm

[0078]

[0079] As shown in Table 5, the 82B high-carbon steel wire rods with specifications of Φ12.0mm~Φ13.0mm produced in this embodiment have an average tensile strength of over 1180MPa, an average reduction of area of ​​over 36%, a sorbite content of over 85%, a grain size finer than grade 7, reduced product aging deviation, a tensile strength of less than 20MPa, and a reduction of area of ​​less than 10%.

[0080] like Figure 6 As shown, fine white linear streaks can be clearly seen in the metallographic image of Φ13.0mm 82B high carbon steel wire rod produced by existing technology. Figure 6 (A) This is a network cementite of grade 2.0 or higher, while these white linear streaks are completely absent in the metallographic image of the Φ13.0mm 82B high-carbon steel wire rod produced in this embodiment. Figure 6 (B) This illustrates that the method in this embodiment completely eliminates network cementite of grade 2.0 and above.

[0081] The following table shows a comparison of the dimensional measurements of 82B high-carbon steel wire rods with specifications of Φ12.0mm, Φ12.5mm, and Φ13.0mm produced in this embodiment with those produced using existing technologies:

[0082] Table 6 Comparison of Dimensions of 82B High Carbon Steel Wire Rods with Specifications of Φ12.0mm~Φ13.0mm

[0083]

[0084] As shown in Table 6, the finished product dimensional accuracy of the 82B high carbon steel wire rod with a specification of Φ12.0mm~Φ13.0mm produced in this embodiment has been effectively improved. Since the minimum size has been increased, the problem of the size being too small on both sides at the 7th to 12th coil position of the head has been solved, which fully meets the requirements of the national standard C-level accuracy, reduces the number of trimming coils, and can increase the yield by 0.4%~0.6%.

[0085] The embodiments described above are only some, not all, of the embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. The scope of protection of the present invention is determined by the scope claimed in the claims. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A method for producing 82B high-carbon steel wire rod, characterized in that, The following hole pattern system is used for production: The system includes a heating furnace and a rolling mill roller table. From the heating furnace outlet along the rolling mill roller table, the following are sequentially arranged: a roughing mill, a first flying shear, an intermediate mill, a second flying shear, a pre-finishing mill, a first water tank group, a third flying shear, a finishing mill, and a second water tank group. The ends of the rolling mill roller table are connected to a wire drawing machine and a Stellmore air-cooling line. The roughing mill has mills 1-6, the intermediate mill has mills 7-12, the pre-finishing mill has mills 13-16, and the finishing mill has mills 17-24. Mills 13, 15, and 17 are listed below. The rolling mills 1, 19, 21, and 23 all have elliptical bores, while the rolling mills 14, 16, 18, 20, 22, and 24 all have round bores. The mill also includes loopers, which are located between rolling mills 13 and 14, and between rolling mill 14 and the finishing mill. A second water tank group is connected after the finishing mill, comprising four water tanks and four sections of reheating roller conveyors, each consisting of guide grooves and rollers. The end of each reheating roller conveyor is connected to pinch rolls and a spinning machine, which is connected to the Stellmore air-cooling line. The production method includes the following steps: Step 1) After the steel billet is heated in the heating furnace, it is rolled in the rolling mill roller table. After being rolled in the roughing mill, the first flying shear is used to cut off the head and tail. Then it enters the intermediate mill for rolling and the second flying shear is used to cut off the head and tail. Step 2) The billet enters the pre-finishing mill and is rolled by mills 13 and 14. It then passes through mills 15 and 16 without load. After exiting mill 14, the billet is pre-cooled by the first water tank group to ensure that the temperature of the billet entering the finishing mill is less than 910℃. Then, the head and tail are cut by the third flying shear. Step 3) The steel billet enters the finishing mill, and the parameters are adjusted according to different finished product specifications as follows: When the finished product specification is Φ12.0 mm, the No.17 and No.18 rolling mills pass through empty, the elliptical hole of the No.19 rolling mill is set with major axis B=29.31 mm and minor axis H=15.84 mm, the circular hole of the No.20 rolling mill is set with radius R=9.85 mm, and then after being rolled by the No.21-24 rolling mills, it is sent out of the finishing mill group. When the finished product specification is Φ12.5 mm, the elliptical hole of the No.17 rolling mill is set with a major axis B = 32.17 mm and a minor axis H = 16.29 mm, and the circular hole of the No.18 rolling mill is set with a radius R = 9.81 mm. After being rolled by the No.19-22 rolling mills, the No.23 and No.24 rolling mills pass through empty and are sent out of the finishing mill group. When the finished product specification is Φ13.0 mm, the elliptical hole of rolling mill No. 17 is set with major axis B = 34.22 mm and minor axis H = 16.30 mm, and the circular hole of rolling mill No. 18 is set with radius R = 10.06 mm. After being rolled by rolling mills No. 19-22, the steel passes through rolling mills No. 23 and No. 24 without load and is sent out of the finishing mill. The steel sent out of the finishing mill is water-cooled by the second water tank group to ensure that the wire drawing temperature is less than 870℃. Step 4) After the steel billet is rolled by the rolling mill roller table, it enters the Stellmore air-cooling line through the wire spinneret to produce the finished product, thus completing the operation.

2. The method for producing 82B high-carbon steel wire rod according to claim 1, characterized in that, In step 2), the parameters at the exit of mill No. 14 are adjusted as follows, depending on the different finished product specifications: When the finished product specification is Φ12.0 mm, the size of the rolled piece at the exit of mill No. 14 is set to Φ23.0 mm, and the exit linear velocity is set to 10.9 m / s; When the finished product specification is Φ12.5 mm, the size of the rolled piece at the exit of mill No. 14 is set to Φ24.1 mm, and the exit linear velocity is set to 10.0 m / s; When the finished product specification is Φ13.0 mm, the size of the rolled piece at the exit of mill No. 14 is set to Φ25.6 mm, and the exit linear velocity is set to 9.5 m / s.

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