Disclosure of Invention
The present invention provides a production system and method for improving the productivity and product quality of a high-speed wire rod production line, aiming at the defects of the prior art. The production system has low construction cost, is easy to realize industrial production and has obvious economic benefit.
The technical scheme provided by the invention is a production method for improving the productivity and the product quality of a high-speed wire production line, which comprises the following steps: the production process sequence of the high-speed wire rod comprises the following steps:
1) heating: heating the steel billet to 950-1250 ℃ by a heating furnace;
2) rolling by a roughing mill set: adopting a horizontal and vertical alternative or flat roller rolling mode to perform 6-pass short stress line rough rolling unit rolling on the square billet heated in the step (1);
3) rolling by a medium rolling mill set: rolling the rolled piece subjected to the rough rolling mill set in the step (2) and subjected to flying shear cropping by a 6-pass or 8-pass short stress line intermediate rolling mill set;
4) controlling rolling by a pre-finishing mill set: after the rolled piece in the step (3) is rolled by the middle rolling mill set, the rolled piece is subjected to 2-pass, 4-pass or 6-pass pre-finishing rolling mill set rolling after the head and the tail of the rolled piece are cut by flying shears;
5) and (3) controlling and cooling after the pre-finishing mill group: performing pre-finishing mill group post-control cooling on the rolled piece subjected to pre-finishing rolling control rolling in the step (4);
6) controlling rolling by a finishing mill group: performing controlled rolling of the finishing mill group after the rolled piece subjected to controlled cooling after the pre-finishing mill group in the step (5) is subjected to head and tail cutting by flying shears in front of the finishing mill group;
7) and (3) controlling and cooling after the finishing mill group: performing controlled cooling after a finishing mill group on the rolled piece subjected to the finish rolling control rolling in the step (6);
8) rolling by a reducing sizing mill set: performing controlled rolling of a 2-pass reducing sizing mill set on the rolled piece subjected to controlled cooling after the finishing mill set in the step (7);
9) and (3) controlling cooling: controlling cooling after rolling the round steel rolled by the reducing sizing mill set for 4 times in the step (8), and ensuring that a water valve of a first water tank is started after the head of the rolled piece passes through the first water tank after rolling during cooling;
10) cutting the head and the tail by high-speed flying shear: shearing the head and tail size specification out-of-tolerance part of the deformed steel bar wire rod subjected to the diameter reduction unit and controlled to be cooled in the step (8);
11) spinning and looping: clamping the qualified rolled piece subjected to the high-speed flying shear and head and tail cutting in the step (10) by a front pinch roll of a laying head, and feeding the clamped rolled piece into the laying head for laying and looping, wherein the laying temperature of the laying head is 700-900 ℃;
12) controlling cooling by an air cooling line: the wire rod coil which is spun by the spinning machine and looped in the step (11) enters an air cooling line for controlled cooling;
13) collecting the collection rolls: and (4) collecting the wire rod coils cooled by the air cooling line in the step (12) by a coil collecting station, cooling by a PF line, bundling, weighing, labeling, coil unloading and warehousing.
As an improvement, when the pre-finishing mill group rolls an empty stand, the empty stand is a middle two-pass corresponding stand; when the two intermediate passes of the pre-finishing mill set pass through the air, tension-free rolling is realized between the racks through a loop, and the head and tail sizes and the strip passing performance of the rolled piece are controlled.
As an improvement, the finishing mill group performs controlled rolling, the number of rolling frames is 2-8, and the number of rolling passes is even.
As an improvement, the finishing mill group controls rolling, when the rolling pass is 2, the roll diameter of the two rolling passes is the same, and under the condition of small roll diameter, the corresponding motor rotating speed does not exceed 85% of the maximum rotating speed rated value.
As an improvement, the outlet size precision of the reducing sizing unit is +/-0.05 mm at most.
As an improvement, the overshoot coefficient of the running speed of the high-speed flying shear is 0.2% -20% compared with that of a rolled piece.
As an improvement, the rolling speed of the reducing sizing mill set is 8.0-220.00 m/s.
As a modification, the step (8) can be replaced by rolling by a reducing mill set: and (5) performing controlled rolling of a 2-pass reducing unit on the rolled piece subjected to controlled cooling after the finish rolling unit in the step (7).
As an improvement, the rolling speed of the reducing mill is 27.0-225.00 m/s.
A production system and a method for improving the productivity and the product quality of a high-speed wire production line are disclosed: the device comprises a heating furnace, a frame roughing mill group, a crop flying shear I, a frame middle mill group, a crop flying shear II, a pre-finishing mill group, a pre-finishing post-finishing water tank, a crop flying shear III, a frame control rolling finishing mill group, a finishing post-finishing water tank, a reducing sizing mill group, a cooling water tank, a high-speed flying shear, a pinch roll and a wire laying head which are sequentially arranged along the rolling production direction.
Compared with the prior art, the invention has the advantages that:
1) the pre-finishing mill group flail frame controls rolling, reduces the motor load of the pre-finishing mill group, and improves the running stability during high-speed rolling;
2) the pre-finishing mill group realizes non-tension rolling through a loop, and after the pre-finishing mill group throws a rack, the distance between the mills is large, stable loop control can be realized, and the head and tail sizes of rolled pieces are not out of tolerance;
3) the finishing mill set controls rolling, micro-tension rolling is realized through pass parameters, and electrical control is simple, stable and reliable;
4) the finishing mill group controls rolling, when the rolling pass is 2, the roll diameter is the same, the rolled piece runs stably, the steel biting accident is not easy to occur, and the productivity and the operating rate are improved;
5) all the finished product outlet frames are reducing sizing machine sets or reducing machine sets, the full-line hole type system is simple, the quantity of matched rolls is small, and the production is simplified;
6) the production line realizes the full-line temperature control, and the product quality is high;
7) the high-speed flying shears are arranged behind the reducing and sizing unit, so that the part with the size and specification of the head and the tail of the rolled piece which are out of tolerance can be sheared, the subsequent links of manually shearing the head and the tail are saved, and the manual labor load of a production line is reduced;
8) negative deviation rolling of the deformed steel bar can be realized, and the metal yield is improved;
9) the production specification range is wide, and all products in the specification range of phi 6.0mm to phi 90.0mm can be produced;
10) the yield of a high-speed wire production line is greatly improved by 20-30 percent compared with the yield of a common high-speed wire production line of a typical 10-frame finishing mill group;
11) the mechanical property, the dimensional accuracy and the performance stability of the wire rod product of the high-speed wire rod product are improved, and the dimensional accuracy of the round steel can reach +/-0.05 mm;
12) the utilization rate of a production line rolling mill can be improved, the operation rate is improved, and the economic benefit is improved.
Detailed Description
The following describes a production system and a method for improving the productivity and the product quality of a high-speed wire production line in detail with reference to the accompanying drawings.
With reference to the attached drawings 1-4, a production method for improving the productivity and the product quality of a high-speed wire production line comprises the following steps:
1) heating: heating the steel billet to 950-1250 ℃ by a heating furnace;
2) rolling by a roughing mill set: adopting a horizontal and vertical alternative or flat roller rolling mode to perform 6-pass short stress line rough rolling unit rolling on the square billet heated in the step (1);
3) rolling by a medium rolling mill set: rolling the rolled piece subjected to the rough rolling mill set in the step (2) and subjected to flying shear cropping by a 6-pass or 8-pass short stress line intermediate rolling mill set;
4) controlling rolling by a pre-finishing mill set: after the rolled piece in the step (3) is rolled by the middle rolling mill set, the rolled piece is subjected to 2-pass, 4-pass or 6-pass pre-finishing rolling mill set rolling after the head and the tail of the rolled piece are cut by flying shears;
5) and (3) controlling and cooling after the pre-finishing mill group: performing pre-finishing mill group post-control cooling on the rolled piece subjected to pre-finishing rolling control rolling in the step (4);
6) controlling rolling by a finishing mill group: performing controlled rolling of the finishing mill group after the rolled piece subjected to controlled cooling after the pre-finishing mill group in the step (5) is subjected to head and tail cutting by flying shears in front of the finishing mill group;
7) and (3) controlling and cooling after the finishing mill group: performing controlled cooling after a finishing mill group on the rolled piece subjected to the finish rolling control rolling in the step (6);
8) rolling by a reducing sizing mill set: performing controlled rolling of a 2-pass reducing sizing mill set on the rolled piece subjected to controlled cooling after the finishing mill set in the step (7);
9) and (3) controlling cooling: controlling cooling after rolling the round steel rolled by the reducing sizing mill set for 4 times in the step (8), and ensuring that a water valve of a first water tank is started after the head of the rolled piece passes through the first water tank after rolling during cooling;
10) cutting the head and the tail by high-speed flying shear: shearing the head and tail size specification out-of-tolerance part of the deformed steel bar wire rod subjected to the diameter reduction unit and controlled to be cooled in the step (8);
11) spinning and looping: clamping the qualified rolled piece subjected to the high-speed flying shear and head and tail cutting in the step (10) by a front pinch roll of a laying head, and feeding the clamped rolled piece into the laying head for laying and looping, wherein the laying temperature of the laying head is 700-900 ℃;
12) controlling cooling by an air cooling line: the wire rod coil which is spun by the spinning machine and looped in the step (11) enters an air cooling line for controlled cooling;
13) collecting the collection rolls: and (4) collecting the wire rod coils cooled by the air cooling line in the step (12) by a coil collecting station, cooling by a PF line, bundling, weighing, labeling, coil unloading and warehousing.
When the pre-finishing mill group rolls an empty stand, the empty stand corresponds to the middle two times; when the two intermediate passes of the pre-finishing mill set pass through the air, tension-free rolling is realized between the racks through a loop, and the head and tail sizes and the strip passing performance of the rolled piece are controlled.
The finishing mill group performs controlled rolling, the number of rolling stands is 2-8, and the number of rolling passes is even.
The finishing mill group controls rolling, when the rolling pass is 2 passes, the roll diameters of the two passes of rolling are the same, and the corresponding motor rotating speed does not exceed 85% of the maximum rotating speed rated value under the condition of small roll diameter.
The outlet size precision of the reducing sizing mill set is +/-0.05 mm at most.
The overshoot coefficient of the running speed of the high-speed flying shear is 0.2-20% compared with the running speed of a rolled piece.
The rolling speed of the reducing sizing mill set is 8.0-220.00 m/s.
The step (8) can be replaced by rolling of a reducing mill set: and (5) performing controlled rolling of a 2-pass reducing unit on the rolled piece subjected to controlled cooling after the finish rolling unit in the step (7).
The rolling speed of the reducing mill set is 27.0-225.00 m/s.
The production system comprises a heating furnace 1, a frame roughing mill unit 2, a crop flying shear I3, a frame middle mill unit 4, a crop flying shear II5, a pre-finishing mill unit 6, a pre-finishing water tank 7, a crop flying shear III8, a frame control rolling finishing mill unit 9, a finish rolling water tank 10, a reducing and sizing mill unit 11, a cooling water tank 12, a high-speed flying shear 3, a pinch roll 14 and a wire laying head 15 which are sequentially arranged along the rolling production direction.
The production system and the method for improving the productivity and the product quality of the high-speed wire production line have the following specific implementation processes:
round steel example: as follows:
(1) heating: heating a billet with the cross section size of 150mm multiplied by 150mm to 170mm multiplied by 170mm to 950 to 1250 ℃ by adopting a walking beam type heating furnace;
(2) rolling by a roughing mill set: performing 6-pass short-stress-line rough rolling mill set rolling on the square billet heated in the step (1) by adopting a horizontal-vertical alternative or flat-roller rolling mode, wherein non-pass rolling and pass rolling can be adopted during rolling, when pass rolling is adopted, the 6-stand rough rolling mill set is a box-type-deformed oval-round-pass system, guides and guards are arranged at the front and the rear of each rolling mill during pass rolling, flying shears are arranged behind the rough rolling mill set, the deformation compression ratio of each pass is controlled to be 1.22-1.43 during rolling, the deformation temperature is 880-1030 ℃, and the running speed of a rolled piece is 0.08-2.00 m/s during rolling of the rough rolling mill set;
(3) rolling by a medium rolling mill set: after being rolled by the rough rolling mill set in the step (2), rolling the rolled piece which is cut by flying shears in the middle of 6 times or 8 times of short stress line rolling mill set, wherein the pass system is an oval-round pass system during rolling, guides and guards are arranged at the front and the back of each rolling mill, the deformation compression ratio of each pass is controlled to be 1.22-1.38, the deformation temperature is 880-1000 ℃, and the running speed of the rolled piece is 0.8-10.00 m/s;
(4) controlling rolling by a pre-finishing mill set: after the rolled piece in the step (3) is rolled by the middle rolling mill set, the rolled piece is subjected to head and tail cutting by flying shears, and then is subjected to 2-pass, 4-pass or 6-pass pre-finishing rolling by the pre-finishing rolling mill set, wherein the front two frames are short stress rolling mills, the rear 4 frames are flat cantilever rolling mills, 6-pass rolling is adopted when small-specification products such as phi 6.0mm and phi 8.0mm are rolled, 4-pass rolling is adopted when large-specification products such as phi 10.0mm and phi 12.0mm are rolled, and 2-pass rolling is adopted when larger-specification products are rolled; when 4-pass rolling is adopted, the empty passing rack is two frames in the middle of the pre-finishing mill set, the tension is controlled by a loop in the middle, the pass system is an oval-round pass system during rolling, guides and guards are arranged at the front and the back of each rolling mill, the loop is arranged between the racks so as to realize tension-free rolling, the deformation compression ratio of each pass is controlled to be 1.20-1.35, the deformation temperature is 860-980 ℃, and the running speed of a rolled piece is 2.0-25.00 m/s;
(5) and (3) controlling and cooling after the pre-finishing mill group: performing pre-finishing mill group post-control cooling on the rolled piece subjected to pre-finishing rolling control rolling in the step (4), wherein the cooling capacity of a single water tank is 30-200 ℃ during cooling, temperature recovery is realized between the water tanks through an air cooling section, and the temperature of the rolled piece is reduced to 100-200 ℃ after pre-finishing rolling and controlled cooling;
(6) controlling rolling by a finishing mill group: performing controlled rolling of the finishing mill group after the rolled piece subjected to controlled cooling after the pre-finishing mill group in the step (5) passes through a front flying shear of the finishing mill group and then is subjected to head and tail cutting, wherein the finishing mill group adopts centralized transmission, the tension between the finishing mill group is adjusted through a pass system, the number of rolling frames of the finishing mill group is 2-8, the pass system is an oval-round pass system during rolling, guides and guards are arranged at the front and the rear of each rolling mill, the deformation compression ratio of each pass is controlled to be 1.20-1.28 in the rolling process, the deformation temperature is 800-950 ℃, and the running speed of the rolled piece is 9.0-95.00 m/s;
(7) and (3) controlling and cooling after the finishing mill group: performing controlled cooling after the rolled piece subjected to the finish rolling control rolling in the step (6) is subjected to a finish rolling unit, wherein the cooling capacity of a single water tank is 30-180 ℃ during cooling, the temperature recovery between the water tanks is realized through an air cooling section, and the temperature of the rolled piece is reduced to 100-250 ℃ after the finish rolling and the controlled cooling;
(8) rolling by a reducing mill set: performing 2-pass reducing unit controlled rolling on the rolled piece subjected to controlled cooling after the finishing rolling unit in the step (7), wherein a pass system is an oval-round-oval-round pass system during rolling, guides and guards are arranged at the front and the back of each rolling mill, the guides and guards before the last rolling mill and the last 3 rolling mill are rolling guides and guards, the rest are sliding guides and guards, the deformation compression ratio of each pass is controlled to be 1.20-1.30, the deformation temperature is 720-900 ℃, and the running speed of the rolled piece is 8.0-120.00 m/s in the rolling process;
(9) and (3) controlling cooling after the reducing sizing mill set: rolling and controlling cooling of the round steel rolled by the reducing and sizing mill set for 4 times in the step (8), wherein a water valve of a first water tank is started after the head of the rolled piece passes through the first water tank after rolling during cooling, the cooling capacity of the single water tank is 30-150 ℃, and the temperature of the rolled piece is reduced to 30-200 ℃ after the round steel is controlled and cooled by the reducing and sizing mill set; (ii) a
(10) Cutting the head and the tail by high-speed flying shear: controlling the cooled deformed steel bar wire rod subjected to the diameter reducing unit in the step (8) to shear the head and tail part out-of-tolerance part, wherein the overshoot coefficient of the running speed of the high-speed flying shear compared with the running speed of a rolled piece is 0.1-10%;
(11) spinning and looping: clamping the qualified rolled piece subjected to the high-speed flying shear and head and tail cutting in the step (10) by a front pinch roll of a laying head, and feeding the clamped rolled piece into the laying head for laying and looping, wherein the laying temperature of the laying head is 700-900 ℃;
(12) controlling cooling by an air cooling line: the wire rod coil which is subjected to wire laying and looping by the wire laying machine in the step (11) is put into an air cooling line for controlled cooling, according to the continuous cooling transformation rule of the round steel, the cooling mode can adopt quick cooling, air cooling or delayed cooling to ensure that the final tissue is qualified, and the temperature of the round steel coil is 350-600 ℃ after the round steel is cooled by the air cooling line;
(13) collecting the collection rolls: and (4) collecting the wire rod coils cooled by the air cooling line in the step (12) by a coil collecting station, cooling by a PF line, bundling, weighing, labeling, coil unloading and warehousing.
Screw-thread steel example: as follows:
(1) heating: heating a billet with the cross section size of 150mm multiplied by 150mm to 170mm multiplied by 170mm to 950 to 1050 ℃ by adopting a walking beam type heating furnace;
(2) rolling by a roughing mill set: performing 6-pass short-stress-line rough rolling mill set rolling on the square billet heated in the step (1) by adopting a horizontal-vertical alternative or flat-roller rolling mode, wherein non-pass rolling and pass rolling can be adopted during rolling, when pass rolling is adopted, the 6-stand rough rolling mill set is a box-type-deformed oval-round-pass system, guides and guards are arranged at the front and the rear of each rolling mill during pass rolling, flying shears are arranged behind the rough rolling mill set, the deformation compression ratio of each pass is controlled to be 1.22-1.43 during rolling, the deformation temperature is 880-1030 ℃, and the running speed of a rolled piece is 0.08-2.00 m/s during rolling of the rough rolling mill set;
(3) rolling by a medium rolling mill set: after being rolled by the rough rolling mill set in the step (2), rolling the rolled piece which is cut by flying shears in the middle of 6 times or 8 times of short stress line rolling mill set, wherein the pass system is an oval-round pass system during rolling, guides and guards are arranged at the front and the back of each rolling mill, the deformation compression ratio of each pass is controlled to be 1.22-1.38, the deformation temperature is 880-1000 ℃, and the running speed of the rolled piece is 0.8-10.00 m/s;
(4) controlling rolling by a pre-finishing mill set: after the rolled piece in the step (3) is rolled by a middle rolling mill set, the rolled piece is subjected to 2-pass, 4-pass or 6-pass pre-finishing rolling mill set for rolling, when small-specification products are rolled, 6-pass rolling is adopted when phi 6.0mm and phi 8.0mm are rolled, when large-specification products are rolled, 4-pass rolling is adopted when phi 10.0mm and phi 12.0mm are rolled, an empty rack is two frames in the middle of the pre-finishing rolling mill set, the tension is controlled by a loop in the middle, the pass system is an oval-round pass system during rolling, guides and guards are arranged at the front and the back of each rolling mill, a loop is arranged between the frames to realize tension-free rolling, the deformation compression ratio of each pass is controlled to be 1.20-1.35 during the rolling process, the deformation temperature is 860-980 ℃, and the operation speed is 2.0 m/s-25.00 m/s;
(5) and (3) controlling and cooling after the pre-finishing mill group: performing pre-finishing mill group post-control cooling on the rolled piece subjected to pre-finishing rolling control rolling in the step (4), wherein the cooling capacity of a single water tank is 30-200 ℃ during cooling, temperature recovery is realized between the water tanks through an air cooling section, and the temperature of the rolled piece is reduced to 100-200 ℃ after pre-finishing rolling and controlled cooling;
(6) controlling rolling by a finishing mill group: performing controlled rolling of the finishing mill group after the rolled piece subjected to controlled cooling after the pre-finishing mill group in the step (5) passes through a front flying shear of the finishing mill group and then is subjected to head and tail cutting, wherein the finishing mill group adopts centralized transmission, the tension between the finishing mill group is adjusted through a pass system, the number of rolling frames of the finishing mill group is 2-8, the pass system is an oval-round pass system during rolling, guides and guards are arranged at the front and the rear of each rolling mill, the deformation compression ratio of each pass is controlled to be 1.20-1.28 in the rolling process, the deformation temperature is 800-950 ℃, and the running speed of the rolled piece is 9.0-95.00 m/s;
(7) and (3) controlling and cooling after the finishing mill group: performing controlled cooling after the rolled piece subjected to the finish rolling control rolling in the step (6) is subjected to a finish rolling unit, wherein the cooling capacity of a single water tank is 30-180 ℃ during cooling, the temperature recovery between the water tanks is realized through an air cooling section, and the temperature of the rolled piece is reduced to 100-250 ℃ after the finish rolling and the controlled cooling;
(8) rolling by a reducing mill set: performing 2-pass reducing unit controlled rolling on the rolled piece subjected to controlled cooling after the finishing mill group in the step (7), wherein a pass system is an oval-round pass system during rolling, guides and guards are arranged at the front and the rear of each rolling mill, the guide and guard in the front of the last rolling mill is a rolling guide and guard in the rear of each rolling mill, the rest is a sliding guide and guard, the deformation compression ratio of each pass is controlled to be 1.20-1.30, the deformation temperature is 720-900 ℃, and the running speed of the rolled piece is 27.0-115.00 m/s;
(9) and (3) controlling cooling after the reducing unit: after rolling, controlling cooling of the deformed steel bar rolled by the reducing unit for 2 passes in the step (8), wherein during cooling, a first water tank water valve is started after the head of a rolled piece passes through a first rolled water tank, the cooling capacity of a single water tank is 30-150 ℃, the surface temperature of the rolled piece after cooling is not lower than the temperature higher than 400 ℃, so that low-temperature martensite structures are prevented from appearing, and after controlling cooling by the reducing unit, the temperature of the rolled piece is reduced to 30-200 ℃;
(10) cutting the head and the tail by high-speed flying shear: controlling the cooled deformed steel bar wire rod subjected to the diameter reducing unit in the step (8) to shear the head and tail part out-of-tolerance part, wherein the overshoot coefficient of the running speed of the high-speed flying shear compared with the running speed of a rolled piece is 0.1-10%;
(11) spinning and looping: clamping the qualified rolled piece subjected to the high-speed flying shear and head and tail cutting in the step (10) by a front pinch roll of a laying head, and feeding the clamped rolled piece into the laying head for laying and looping, wherein the laying temperature of the laying head is 700-900 ℃;
(12) controlling cooling by an air cooling line: controlling and cooling the wire rod coil which is subjected to spinning and looping by the spinning machine in the step (11) in an air cooling line, wherein the first sections of cooling sections adopt a rapid cooling mode according to the continuous cooling transformation rule of the deformed steel bar so as to ensure that the final structure is fine ferrite and pearlite and low-temperature structures such as martensite structures do not appear during cooling, and the temperature of the deformed steel bar coil is 400-550 ℃ after the deformed steel bar is cooled by the air cooling line;
(13) collecting the collection rolls: and (4) collecting the wire rod coils cooled by the air cooling line in the step (12) by a coil collecting station, cooling by a PF line, bundling, weighing, labeling, coil unloading and warehousing.
The process parameters of the typical screw-thread steel HRB400E product and the mechanical property data of the screw-thread steel HRB400E are respectively shown in the following tables 1 and 2:
TABLE 1 Process parameters for typical screw-thread steel HRB400E products of the invention
TABLE 2 mechanical Properties of the deformed steel bar HRB400E
The present invention and its embodiments have been described above, and the description is not intended to be limiting, and the drawings are only one embodiment of the present invention, and the actual structure is not limited thereto. In summary, those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention without departing from the spirit and scope of the invention as defined by the appended claims.