CN111389906A

CN111389906A - Method and system for producing medium and large-sized bars

Info

Publication number: CN111389906A
Application number: CN202010208404.5A
Authority: CN
Inventors: 周民; 白亚斌; 韩会全; 马靳江; 牛强
Original assignee: CISDI Engineering Co Ltd; CISDI Technology Research Center Co Ltd
Current assignee: CISDI Engineering Co Ltd; CISDI Technology Research Center Co Ltd
Priority date: 2020-03-23
Filing date: 2020-03-23
Publication date: 2020-07-10

Abstract

The invention relates to a method and a system for producing medium and large-sized bars, belonging to the technical field of bar production in the ferrous metallurgy industry. The production method comprises the following steps of heating: heating the steel billet to 900-1300 ℃; rolling: rolling the heated billet at the running speed of 1.0-18.00 m/s; cutting to length and steel feeding: carrying out fixed-length shearing on the rolled piece, and braking the fixed-length bar material subjected to fixed-length shearing to finish steel feeding; and (3) cooling: the fixed-length bar material runs in a stepping mode and is cooled; the production system comprises a heating unit, a rolling unit, a fixed-length shearing and steel feeding unit and a cooling bed which are sequentially connected. The invention directly carries out fixed-length shearing after rolling and adopts a mode of high-speed steel feeding or magnetic force braking apron board to brake, the braking distance is shortened, the bar does not undergo multiple-length shearing, a cooling bed with multiple-length is not needed, the area of the cooling bed is small, the equipment and the working procedures are effectively reduced, the length of a production line is shortened, and the investment is reduced.

Description

Method and system for producing medium and large-sized bars

Technical Field

The invention belongs to the technical field of bar production in the ferrous metallurgy industry, and relates to a method and a system for producing medium and large-sized bars.

Background

As one of the important products in the steel industry, deformed steel bars and high-quality steel bars are widely used in the industries of buildings, machinery and metal products. In recent years, the yield is continuously increased, the yield reaches 2.68 hundred million tons in 2017, and the yield reaches 25.57 percent of the total amount of steel in China.

Referring to fig. 1, 2, 13 and 14, the production process of the general high-quality steel bar mainly includes: heating by a heating furnace, rolling by a rough and medium finishing mill set, cutting the head and the tail by flying shears after the rolling mill set, cooling by water tanks before and after the finishing mill set, rolling by a reducing mill set, controlling and cooling after reducing, shearing by a multiple length flying shear, cooling by a cooling bed, shearing by a fixed length cold shear, collecting by a non-fixed length, collecting by crossing a cross-frame, counting, aligning, bundling, labeling, weighing and the like. When producing the deformed steel bar, a slitting rolling production process can be adopted. And part steel works adopt high-speed steel feeding system to produce screw-thread steel and ordinary round steel bar, and the main production flow mainly comprises: heating by a heating furnace, rolling by a rough and medium finishing mill set, cutting the head and the tail by flying shears behind the rolling mill set, cooling by water tanks in front and at the back of the finishing mill set, rolling by a high-rod finishing mill set, controlling and cooling behind the high-rod finishing mill set, shearing by multiple-length flying shears, cooling by a cooling bed, shearing by fixed-length cold shears, collecting by non-fixed-length, collecting by crossing a rack, counting, aligning, bundling, labeling, weighing and the like.

Whether the production flow of the common bar or the high-speed steel feeding production flow has the following defects: 1. the production flow is complex, and after rolling by multiple units, the rolled piece needs to be subjected to procedures of multiple-length shearing, cooling bed cooling, fixed-length shearing, non-fixed-length collection, counting, aligning, bundling, labeling, weighing and the like; 2. the production line has more and complicated equipment and is easy to break down; 3. the rolled piece needs to be processed through multiple processes, and a single continuous casting billet is produced, so that non-fixed length is easy to occur, and the yield of a production line is reduced; 4. when the slitting rolling production process is adopted to produce the deformed steel bar, the process is limited, and the relatively accurate negative deviation rolling cannot be realized; 5. when the slitting rolling production process is adopted to produce the deformed steel bar, the requirement on the material type is more strict, and the amount of the end cutting is increased by 0.5 to 0.7 percent compared with the conventional bar; 6. when the slitting rolling production process is adopted to produce the deformed steel bar, burrs are easy to appear on the product, folding or crack defects are easy to cause, and the yield is low; the billet defects are exposed after being cut to form surface defects; twisting is needed after cutting, and a twisting guide and guard are needed; 7. limited by production technology, the high-speed steel feeding system has surface defects when producing high-quality steel, and only can be used for rolling steel grades such as deformed steel, plain carbon steel and the like with general requirements on surface quality; 8. limited by production technology, the distance between the multi-length flying shears and a cooling bed after rolling is large, generally about 80m, the length of a rolling line is large, the area of a factory building is large, and the investment is high;

aiming at the problems of complex system, high failure rate, long production line, high investment and the like in the existing bar production, the invention provides an ultrashort-flow medium-large-size bar production line and a low-cost high-efficiency bar production method, which can greatly shorten the length of the production line, reduce the complexity of the production system, reduce the failure rate of equipment, reduce the investment cost, improve the production stability, improve the utilization rate of a rolling mill and improve the economic benefit.

Disclosure of Invention

In view of this, the invention aims to provide a method and a system for producing bars with medium and large specifications, which simplify a production system for bars with medium and large specifications and improve the production efficiency of bars with medium and large specifications.

In order to achieve the purpose, the invention provides the following technical scheme: a method for producing medium and large-sized bars comprises the following steps of heating: heating the steel billet to 900-1300 ℃; rolling: rolling the heated billet at the running speed of 1.0-18.00 m/s; cutting to length and steel feeding: carrying out fixed-length shearing on the rolled piece, and braking the fixed-length bar material subjected to fixed-length shearing to finish steel feeding; and (3) cooling: the sized bar is run in a step-wise fashion and cooled.

Optionally, in the step of "heating", the cross-sectional dimension of the steel billet is 150mm × 150mm to 200mm × 200mm, and the steel billet is a square billet or a rectangular billet.

Optionally, the "rolling" step includes the following substeps, rough rolling: rolling the heated billet, wherein the deformation compression ratio of each pass is controlled to be 1.20-1.45 in the rolling process, the deformation temperature is 880-1200 ℃, and the running speed of a rolled piece is 0.075 m/s-3.00 m/s; intermediate rolling: rolling the rough rolled piece, wherein the deformation compression ratio of each pass is controlled to be 1.20-1.40, the deformation temperature is 850-1100 ℃, and the running speed of the rolled piece is 1.0-10.00 m/s; finish rolling: and rolling the rolled piece after the intermediate rolling, wherein the deformation compression ratio of each pass is controlled to be 1.20-1.40, the deformation temperature is controlled to be 800-1050 ℃, and the running speed of the rolled piece is 1.0-18.00 m/s.

Optionally, in the step of rough rolling, the heated billet is rolled in a horizontal and vertical alternating or flat roll rolling mode, 6 passes of short stress line rolling are performed on the square billet, and 5 passes or 7 passes of short stress line rolling are performed on the rectangular billet; in the step of 'intermediate rolling', 6-pass or 8-pass short stress line rolling is carried out on the rolled piece after the rough rolling is finished; in the step of finish rolling, the rolled piece after the finish rolling is subjected to 6 times of short stress line rolling.

Optionally, the "rolling" step further includes the following substeps, the reducing rolling substep: and reducing the diameter of the rolled piece after finish rolling for 3-5 times, wherein the deformation compression ratio of each time is controlled to be 1.01-1.35, the deformation temperature is 730-950 ℃, and the running speed of the rolled piece is 1.0-18.0 m/s.

Optionally, in the step of "cooling", the sized bar is fed onto a cooling bed and runs on the cooling bed in a stepping mode, when the bar runs to a roller bed aligned with the cooling bed, the bar is cooled on line through a water-cooling nozzle below the cooling bed, and an air blowing nozzle is arranged behind the water-cooling nozzle to blow dry the residual cooling water on the surface of the bar.

A production system for large and medium-sized bars comprises a heating unit, a rolling unit, a fixed-length shearing unit, a steel feeding unit and a cooling bed which are sequentially connected; the rolling unit comprises a rough rolling unit and a middle rolling unit which are connected in sequence, and a high-speed finishing rolling unit or a reducing rolling unit is connected behind the middle rolling unit; the running speed of the output rolled piece of the rolling unit is 1.0-18.0 m/s;

optionally, the steel feeding unit is a skirting board system or a high-speed steel feeding system, the high-speed finishing mill set is connected with the cooling bed through the high-speed steel feeding system, and the reducing mill set is connected with the cooling bed through the skirting board system; the roughing mill group adopts the non-groove rolling or the groove rolling; the hole pattern systems of the finishing mill group and the middle mill group are both oval-round hole pattern systems, and guides and guards are arranged at the front and the rear of each mill of the finishing mill group and the middle mill group.

Optionally, the heating unit is a walking beam type heating furnace or an electromagnetic induction heating device; the apron board system is a magnetic braking apron board, and the high-speed steel feeding system comprises a pinch roll, a double-way guide groove and a tail clamping brake.

Optionally, the cold bed type automatic bundling machine further comprises a bundling unit, wherein the bundling unit is connected with the cold bed and comprises an automatic bundling device, a bundling roller way and a bundling collecting rack which are sequentially connected. The invention has the beneficial effects that:

(1) the invention directly carries out fixed-length shearing after rolling is finished, and does not carry out multiple-length shearing, thereby reducing equipment and working procedures; (2) the bar is braked by adopting high-speed steel feeding or a mode of combining a braking apron board and a magnetic apron board, so that the braking distance of the bar is shortened, the length of a production line is shortened, and the investment is reduced; (3) the direct sizing is adopted, a cooling bed with multiple length is not needed, the area of the cooling bed is small, the length of a production line is shortened, and the investment is reduced; (4) the cooling bed adopts the nozzle to carry out bar material controlled cooling, so that the cooling efficiency of the cooling bed is improved, and the product quality is improved; (5) the sizing cold shear, the over-span inspection bench and other equipment are not required to be configured in the finishing process, the production line equipment is less, and the failure rate is low; (6) the product has wide production specification range, and can produce all deformed steel bars in the specification range of phi 16.0mm to phi 50.0mm and all round steel bar products in the specification range of phi 16.0mm to phi 90.0 mm; (7) the product has high dimensional precision due to the adoption of a single rolling method; (8) the negative deviation rolling of the deformed steel bar can be realized, and the metal yield is improved; (9) because the direct sizing is adopted, the high-speed continuous casting and rolling process or the endless rolling process of the preorder is combined, the single-line gapless production is realized, the production line has high yield, the hourly output of the production line is high, the production line rolling mill has high efficiency, and because of no head and tail, the head and tail of the sized bar have no temperature difference, the size is uniform, and the performance is stable.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.

Drawings

For the purposes of promoting a better understanding of the objects, aspects and advantages of the invention, reference will now be made to the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic view of a conventional layout of a slitting bar production line;

FIG. 2 is a schematic view of a conventional high-speed bar production line arrangement;

FIG. 3 is a schematic view of the layout of a reducing rolling line;

FIG. 4 is a schematic layout of a high-speed finish rolling line;

FIG. 5 is a schematic layout of a high-speed steel feeding system;

FIG. 6 is a schematic view of the bar on the roller conveyor during magnetic braking;

FIG. 7 is a schematic view of the descending of the magnetic braking apron of the bar;

FIG. 8 is a schematic view of the magnetic braking apron plate of the bar ascending;

FIG. 9 is a schematic view of the bar on the cooling bed during magnetic braking;

FIG. 10 is a schematic structural view of a magnetic braking apron board;

FIG. 11 is a schematic structural view of a cooling bed device;

FIG. 12 is a schematic layout of the automatic bundling apparatus, bundling roller table and bundling collection gantry;

FIG. 13 is a cloud of temperature of the cross section of a cooling bed bar on a conventional bar;

FIG. 14 is a temperature cloud of the cross section of a conventional rod bar lower cooling bed.

Reference numerals:

the device comprises a heating furnace 1, a rough rolling unit 2, a middle rolling unit 3, a finishing rolling unit 4, a cooling bed 5, a crop head flying shear 6, a water cooling box 7, a double-length flying shear 8, a cooling bed inlet roller way 9, a cooling bed output roller way 10, a fixed-length flying shear 11, a finished product collecting device 12, a waste product collecting device 13, a high-speed bar finishing rolling unit 14, a tail clamping brake 15, a rotating hub 16, a continuous casting billet connecting and electromagnetic induction heat supplementing device 17, a reducing unit 18, a magnetic braking apron board 19, a cooling bed cooling control device 20, a pinch roll 21, a point switch 22, a double-way guide groove 23, a bar 24, a conveying roller way 25, a water cooling water tank 26, a purging main pipe 27, a purging nozzle 28, an automatic bundling device 29, a bundling roller way 30 and a bundling collecting rack 31.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention in a schematic way, and the features in the following embodiments and examples may be combined with each other without conflict.

Wherein the showings are for the purpose of illustrating the invention only and not for the purpose of limiting the same, and in which there is shown by way of illustration only and not in the drawings in which there is no intention to limit the invention thereto; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc., based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of description, but it is not an indication or suggestion that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes, and are not to be construed as limiting the present invention, and the specific meaning of the terms may be understood by those skilled in the art according to specific situations.

Example 1

Referring to FIGS. 3 to 12, production parameters are selected with reference to tables 1 and 2 for the production of a threaded steel of 40mm phi as an example. The production process comprises the following steps: electromagnetic induction heat-up of endless continuous casting billets, rolling of a roughing mill set, flying shear head and tail after roughing, rolling of a middle mill set, flying shear head and tail after middle rolling, water cooling after middle rolling, flying shear head and tail before reducing, rolling of a reducing mill set, water cooling after reducing, sizing flying shear, braking of a magnetic braking apron plate on a cooling bed, cooling of a sizing cooling bed, control cooling on the cooling bed, counting of bars, bundling, alignment, weighing and delivery of finished products.

The production implementation process specifically comprises the following steps:

(1) connecting and heating the endless continuous casting blank by adopting a continuous casting blank connecting and electromagnetic induction heat supplementing device 17, wherein the surface temperature of the continuous casting blank after heat supplementing is 930 +/-30 ℃, and the biting temperature of the roughing mill set 2 is not lower than 900 ℃;

(2) and (3) rolling by the roughing mill group 2 and cutting the head after roughing: in the embodiment, a horizontal and vertical alternative rolling mill is adopted to perform 6-pass short-stress-line rough rolling mill set rolling on the square billet which is connected and heated by the endless billet in the step (1), the continuous rolling mill and the groove rolling can be adopted, when the groove rolling is adopted, the rough rolling mill set 2 is a box-ellipse-circular groove system, guides and guards are arranged at the front and the back of each rolling mill when the groove rolling is adopted, a cutting-head flying shear 6 is arranged at the back of the rough rolling mill set, the deformation compression ratio of each pass in the rolling process is 1.30, the deformation temperature is 880-950 ℃, the rough rolling biting speed is 0.28m/s, and the outlet speed of the rough rolling mill set is 1.35 m/s; and after rolling, the head and the tail of the rolled piece are cut by a head cutting flying shear 6.

(3) Rolling by the middle rolling mill group 3: carrying out 4-pass short stress line intermediate mill set rolling on the rolled piece subjected to rough rolling in the step (2) and subjected to head and tail cutting by head and tail cutting flying shears 6, 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 mill, the deformation compression ratio of each pass is controlled to be 1.30, the deformation temperature is 850-900 ℃, the intermediate mill entry speed is 1.35m/s, and the outlet speed of the intermediate mill set is 3.79 m/s; after rolling, the rolled piece is recovered by water cooling through a water cooling box 7 and is cut at the head and the tail by a cutting flying shear 6.

(4) Rolling by a reducing mill 18: and (3) after the intermediate rolling, water cooling and recovery, and flying shear head and tail cutting, rolling the rolled piece in the step (3) by using a 2-pass two-roller reducing unit, wherein the pass system is an oval-round pass system, guides and guards are arranged at the front and the rear of each rolling mill during rolling, the deformation compression ratio of each pass is controlled to be 1.25, the deformation temperature is 730-850 ℃, the reducing biting speed is 3.79m/s, the outlet speed of the reducing unit is 5.9m/s, the diameter of the finished product after the reducing outlet is 40.0mm, and the bar material rolled by the reducing unit 18 is controlled and cooled.

(5) Cutting to length and steel feeding: cooling the bar rolled by the reducing unit 18 in the step (4) through the water cooling box 7, cutting the bar into a fixed length of 12m through a fixed length flying shear 11, accelerating the previous steel after the fixed length cutting, wherein the acceleration distance is 18.0m, pulling the previous bar apart from the second bar by a distance after the acceleration, rapidly braking the previous bar through a magnetic braking apron board 19 at the moment, electrifying a magnetic coil when the magnetic braking apron board 19 receives a braking signal to form the magnetic apron board, and the action sequence is as follows:

(a) the magnetic braking apron board 19 is consistent with the conveying roller way 25, and the bar 24 gradually inclines to slide towards the side of the magnetic braking apron board 19 in the running process;

(b) the magnetic braking skirt board 19 moves downwards to form a fall with the conveying roller way 25, and the bar slides to the cooling bed side along the magnetic braking skirt board 19;

(c) the magnetic braking apron board 19 moves upwards to form a height difference with the conveying roller way 25, so that the next bar 24 is prevented from sliding into the magnetic braking apron board 19, and the bar 24 on the magnetic braking apron board 19 continuously slides towards one side of the cooling bed 5 along the magnetic braking apron board 19;

(d) the magnetic braking apron board 19 returns to the original position, the previous bar 24 falls into the tooth groove of the cooling bed 5 to move step by step, after the braking signal of the next bar 24 is received and sent out, the actions are repeated, the braking period of the magnetic braking apron board 19 under the condition of the technological parameters is 2.15s, and the acceleration is (-0.6g) - (0.7g) during braking.

(6) Cooling by a cooling bed: after the rod material 24 after being sized is fed onto the cooling bed 5, the rod material runs in a tooth groove of the cooling bed 5 in a stepping mode, the stepping period of the cooling bed 5 is 2.15s, when the rod material runs to the cooling bed to align to a roller way, the rod material is cooled through the cooling bed cooling control device 20 below the cooling bed, in order to ensure that the upper surface and the lower surface are uniformly cooled, the rod material 24 rolls while being cooled, in the embodiment, the cooling bed cooling control device 20 comprises a water

cooling water tank

26 and 2 groups of blowing nozzles 28, the blowing nozzles are water cooling nozzles 28, and the groups of blowing nozzles 28 are communicated with the water cooling water tank 26 through a blowing main pipeline 27. The distance between the same group of the blowing nozzles 28 is 0.2-0.5 m, the distance between the different groups of the blowing nozzles 28 is 0.5-3.0 m, the blowing water pressure is 0.2-1.0 MPa, after the blowing nozzles 28 are blown and cooled, the blowing nozzles are blown by compressed air nozzles, the distance between the air blowing nozzles is 0.2-0.5 m, the distance between the air blowing nozzles and the water cooling nozzles is 0.5-1.0 m, and when the bar 24 runs to the cooling bed output roller table 10, the surface temperature of the bar is about 296 ℃.

(7) Bundling and collecting: an automatic bundling device 29, a bundling roller table 30 and a bundling and collecting rack 31 are arranged at the tail end of the cooling bed 5, and the rods 24 are counted, bundled, labeled and weighed, and then transported to a finished product warehouse by a crown block and a horizontal wagon or directly taken out of the warehouse by an automobile.

Example 2

Referring to fig. 3 to 12, taking the production of deformed steel bar with a diameter of 16mm as an example, the production parameters are selected according to table 1 and table 2, and the production process sequence includes: electromagnetic induction heat-supplementing for endless continuous casting billets, rolling by a roughing mill set, flying shearing head and tail after roughing, rolling by a middle mill set, water-cooling flying shearing head and tail after middle rolling, rolling by a finishing mill set, water-cooling after finishing, flying shearing head and tail before reducing, rolling by a reducing mill set, water-cooling after reducing, sizing flying shears, braking upper cooling bed by a magnetic braking apron plate, cooling by a sizing cooling bed, cooling by control on the cooling bed, counting bars, bundling, aligning, weighing and discharging finished products out of a warehouse.

(1) connecting and heating endless continuous casting blanks by adopting a continuous casting blank connecting and electromagnetic induction heat supplementing device 17, wherein the surface temperature of the continuous casting blanks after heat supplementing is 930 +/-30 ℃, the biting temperature of a roughing mill set 2 is not lower than 900 ℃, when the casting blanks need to be connected, a front casting blank and a rear casting blank are welded by adopting a casting blank connecting device such as a headless welder, and the casting blanks are conveyed to the roughing mill set through a roller way, the section of each casting blank is 165mm × 165mm, and the conveying speed of each casting blank is 0.12 m/s.

(2) And (3) rolling by the roughing mill group 2: and (3) performing 6-pass short stress line rough rolling by using a horizontal and vertical alternative rolling mill on the square billet connected and heated in the step (1), wherein a non-pass rolling or pass rolling is adopted, and a guide and guard are arranged at the front and the rear of each rolling mill when pass rolling is adopted. In the embodiment, pass rolling is adopted, the roughing mill set 2 is a box-oval-round pass system, a head cutting flying shear 6 is arranged behind the roughing mill set 2, and the head cutting flying shear 6 is used for cutting the head of the rough-rolled piece; in the rolling process, the deformation compression ratio of each pass is 1.30, the deformation temperature is 880-950 ℃, the roughing rolling biting speed is 0.12m/s, and the outlet speed of the roughing mill group 2 is 0.57 m/s; and (4) cutting the head and the tail of the rolled piece by using a head cutting flying shear 6.

(3) Rolling by the middle rolling mill group 3: after the rolled piece in the step (2) is rolled by the rough rolling mill set 2, and the rolled piece is subjected to head and tail cutting by flying shears, 6-pass short-stress-line intermediate rolling mill set 3 rolling is carried out, 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 deformation compression ratio of each pass is controlled to be 1.30, the deformation temperature is 850-900 ℃, the intermediate rolling biting speed is 0.57m/s, and the outlet speed of the intermediate rolling mill set 3 is 2.68 m/s; after rolling, the rolled piece is subjected to water cooling recovery by a water cooling box 7 and is cut at the head and the tail by a head cutting flying shear 6.

(4) And (4) rolling by a finishing mill group: after the rolled piece in the step (3) is rolled by the middle rolling mill set 3, the rolled piece is cooled and recovered by water and is subjected to flying shear head and tail cutting, 6-pass short-stress-line finishing rolling mill set 4 rolling is carried out, 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 deformation compression ratio of each pass is 1.25, the deformation temperature is 800-900 ℃, the finishing rolling biting speed is 2.68m/s, and the outlet speed of the finishing rolling mill set 4 is 10.24 m/s; after rolling, the rolled piece is subjected to water cooling recovery by a water cooling box 7 and is cut at the head and the tail by a head cutting flying shear 6.

(5) Rolling by a reducing mill 18: and (3) rolling the rolled piece which is rolled by the finishing mill group 4 in the step (4), cooled by water, restored and cut by flying shears to be head and tail by a 2-pass reducing mill group 18, wherein the reducing mill group 18 is a two-roll reducing mill group in the embodiment. The pass system is an oval-round pass system, guides and guards are arranged at the front and the back of each rolling mill during rolling, the deformation compression ratio of each pass is controlled to be 1.25, the deformation temperature is 730-850 ℃, the reducing and biting speed is 10.24m/s, the outlet speed of the reducing unit 18 is 16.0m/s, and the diameter of a finished bar product after reducing is 16.0 mm;

(6) cutting to length and steel feeding: cooling the bar rolled by the reducing unit 18 in the step (5) by the water cooling box 7, then cutting the bar into 12m fixed length by the fixed length flying shear 11, accelerating the previous bar after the fixed length cutting, wherein the accelerating distance is 18.0m, pulling apart a distance between the previous bar and the second bar after the accelerating, rapidly braking the previous bar by the magnetic braking apron board 19 at the moment, electrifying the magnetic coil when the magnetic braking apron board 19 receives a braking signal to form the magnetic apron board, and the action sequence is as follows:

(d) the magnetic braking apron board 19 returns to the original position, the previous bar 24 falls into the tooth groove of the cooling bed 5 to move step by step, after the braking signal of the next bar 24 is received and sent out, the actions are repeated, the braking period of the magnetic braking apron board 19 under the condition of the technological parameters is 1.05s, and the acceleration is (-0.6g) - (0.7g) during braking.

(7) Cooling by a cooling bed: after the bar material is sized, the bar material is moved in a tooth groove of the cooling bed 5 in a stepping mode, the stepping period of the cooling bed 5 is 1.05s, and when the bar material is moved to an alignment roller way of the cooling bed 5, the bar material is cooled through a cooling bed cooling control device 20 below the cooling bed, and in order to ensure that the upper surface and the lower surface are uniformly cooled, the bar material 24 rolls while being cooled. In this embodiment, the cooling bed controlled cooling device 20 includes 2 groups of purging nozzles 28, the purging nozzles 28 are water cooling nozzles, the distance between the purging nozzles 28 in the same group is 0.2m to 0.5m, the distance between the purging nozzles 28 in different groups is 0.5m to 3.0m, and the water pressure of the purging nozzles 28 is 0.2MPa to 1.0 MPa. After being cooled by a plurality of groups of blowing nozzles 28, the bar is blown by compressed air nozzles, the distance between the air blowing nozzles is 0.2 m-0.5 m, the distance between the air blowing nozzles and the water cooling nozzles is 0.5 m-1.0 m, and when the bar runs to the output roller table 10 of the cooling bed, the surface temperature of the bar is about 298 ℃.

(8) Bundling and collecting: at the end of the cooling bed 5, an automatic bundling device 29, a bundling roller table 30 and a bundling collecting rack 31 are arranged, and the rods 24 are counted, bundled, labeled and weighed, and then transported to a finished product warehouse by a crown block and a horizontal wagon or directly taken out of the warehouse by an automobile.

Example 3

Referring to FIGS. 3 to 12, production parameters are selected with reference to tables 1 and 2 for the production of a threaded steel of 40mm phi as an example. The production process comprises the following steps: electromagnetic induction heat compensation of endless continuous casting billets, rolling of a roughing mill set, flying shear head and tail cutting after roughing, rolling of a middle mill set, water cooling after roughing, flying shear head and tail cutting before high-speed bar rolling, rolling of a high-speed bar set, water cooling after rolling of the high-speed bar set, sizing flying shear, steel feeding of a high-speed steel feeding system, control cooling on a cooling bed, bar counting, bundling, alignment, weighing and finished product delivery.

(1) connecting and heating endless blanks, namely connecting and heat-supplementing endless continuous casting blanks by using a continuous casting blank connecting and electromagnetic induction heat-supplementing device 17, wherein in the embodiment, a continuous casting blank connecting device of a endless welding machine is used for welding front and rear two casting blanks, conveying the casting blanks to a roughing mill group through a roller way, and after heat-supplementing, controlling the surface temperature of the continuous casting blanks to be 930 +/-30 ℃ so as to ensure that the biting temperature of the roughing mill group 2 is not lower than 900 ℃, the section of the casting blank is 165mm × 165mm, and the conveying speed of the casting blank is 0.28 m/s;

(2) and (3) rolling by the roughing mill group 2: and (3) carrying out 6-pass short stress line rough rolling unit rolling on the square billet which is subjected to the endless billet connection and heating in the step (1) by adopting a horizontal and vertical alternative rolling mill, wherein the pass-free rolling or pass rolling can be adopted. In the embodiment, pass rolling is adopted, a roughing mill set is a box-type-ellipse-round pass system, guides and guards are arranged at the front and the rear of each rolling mill, a head cutting flying shear 6 is arranged behind the roughing mill set 2, the deformation compression ratio of each pass in the rolling process is 1.30, the deformation temperature is 880-950 ℃, the roughing rolling biting speed is 0.28m/s, the outlet speed of the roughing mill set is 1.35m/s, and rolled pieces are subjected to head and tail cutting by the head cutting flying shear 6 after being subjected to roughing rolling.

(3) Rolling by the middle rolling mill group 3: and (3) carrying out 4-pass short-stress-line intermediate rolling mill set 3 rolling on the rolled piece subjected to rough rolling in the step (2) and subjected to head and tail cutting by the head and tail cutting flying shears 6, 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 deformation compression ratio of each pass is controlled to be 1.30, the deformation temperature is 850-900 ℃, the intermediate rolling biting speed is 1.35m/s, the outlet speed of the intermediate rolling mill set is 3.79m/s, and the rolled piece rolled by the intermediate rolling mill set is subjected to water cooling and recovery by a water cooling box 7 and is subjected to head and tail cutting by the head cutting flying shears 6.

(4) Rolling by a high-speed bar machine set: and (3) after the intermediate rolling, performing water cooling and recovery on the rolled piece subjected to the head and tail cutting by flying shears after the intermediate rolling in the step (3), performing 2-pass high-speed bar rolling by using a bar unit 14, wherein a pass system is an oval-round pass system, guides and guards are arranged at the front and the back of each rolling mill during rolling, the deformation compression ratio of each pass is controlled to be 1.25, the deformation temperature is 730-850 ℃, the diameter reduction gripping speed is 10.24m/s, the outlet speed of the high-speed bar unit 14 is 16.0m/s, the finished product diameter is 40.0mm after the outlet of the high-speed bar unit 14, and the bar rolled by the high-speed bar unit 14 is cooled by using a water cooling box 7.

(5) Cutting to length and steel feeding: after being cooled, the bars rolled by the high-speed bar machine set in the step (4) are subjected to fixed-length shearing by a fixed-length flying shear 11 after passing through a pinch roll 21 and a switch 22, the front bar after being sheared enters one path of a two-path guide groove 23, the rear bar enters the other path of the two-path guide groove, the front bar is forcibly braked in a rotating hub 16 through a tail clamping brake 15, the front bar automatically falls into a tooth groove of a cooling bed 5 after being braked by the rotation of the rotating hub 16, and the rear bar enters the rotating hub 16 through the other path of the two-path guide groove 23 and goes to the cooling bed 5 after being braked.

(6) Cooling by a cooling bed: after the bar material is sized, the bar material runs in a tooth groove of the cooling bed 5 in a stepping mode, the stepping period of the cooling bed 5 is 2.15s, and when the bar material runs to an alignment roller way of the cooling bed 5, the bar material is cooled through a plurality of groups of blowing nozzles 28 below the cooling bed 5, so that the upper surface and the lower surface of the bar material are uniformly cooled, and the bar material rolls. In this embodiment, the cooling bed controlled cooling device 20 includes 2 groups of blowing nozzles 28, the blowing nozzles 28 are water cooling nozzles, the blowing nozzles 28 in different positions of the 2 groups spray water, the interval between the blowing nozzles 28 in the same group is 0.2m to 0.5m, the interval between the blowing nozzles 28 in different groups is 0.5m to 3.0m, the water pressure of the blowing nozzles 28 is 0.2MPa to 1.0MPa, after cooling by the blowing nozzles 28, the blowing is performed by compressed air nozzles, the interval between the air blowing nozzles is 0.2m to 0.5m, the interval between the air blowing nozzles and the blowing nozzles 28 is 0.5m to 1.0m, and when the bar runs to the cooling bed output roller table 10, the surface temperature of the bar is about 296 ℃.

(7) Bundling and collecting: at the end of the cooling bed 5, an automatic bundling device 29, a bundling roller table 30 and a bundling collecting rack 31 are arranged, and the rods 24 are counted, bundled, labeled and weighed, and then transported to a finished product warehouse by a crown block and a horizontal wagon or directly taken out of the warehouse by an automobile.

Example 4

Referring to fig. 3 to 12, taking the production of deformed steel bar with a diameter of 16mm as an example, the production parameters are selected according to table 1 and table 2, and the production process sequence includes: electromagnetic induction heat compensation of endless continuous casting billets, rolling of a roughing mill set, flying shear head and tail after roughing, rolling of a middle mill set, water cooling after roughing, flying shear head and tail before finishing, rolling of a finishing mill set, water cooling after finishing, flying shear head and tail before high-speed bar rolling, rolling of a high-speed bar set, water cooling after rolling of the high-speed bar set, sizing flying shear, steel feeding of a high-speed steel feeding system, control cooling on a cooling bed, bar counting, bundling, alignment, weighing and finished product delivery;

(1) connecting and heating endless blanks, namely connecting and heat-supplementing endless continuous casting blanks by using a continuous casting blank connecting and electromagnetic induction heat-supplementing device 17, wherein in the embodiment, a continuous casting blank connecting device of a endless welding machine is used for welding front and rear two casting blanks, conveying the casting blanks to a roughing mill group through a roller way, and after heat-supplementing, controlling the surface temperature of the continuous casting blanks to be 930 +/-30 ℃ so as to ensure that the biting temperature of the roughing mill group 2 is not lower than 900 ℃, the section of the casting blank is 165mm × 165mm, and the conveying speed of the casting blank is 0.12 m/s;

(2) and (3) rolling by the roughing mill group 2: and (3) carrying out 6-pass short stress line rough rolling unit rolling on the square billet which is subjected to the endless billet connection and heating in the step (1) by adopting a horizontal and vertical alternative rolling mill, wherein the pass-free rolling or pass rolling can be adopted. In the embodiment, pass rolling is adopted, a roughing mill set is a box-type-ellipse-round pass system, guides and guards are arranged at the front and the back of each rolling mill, a cutting flying shear 6 is arranged at the back of the roughing mill set 2, and the cutting flying shear 6 is used for cutting the head of a rolled piece after roughing rolling; in the rolling process, the deformation compression ratio of each pass is 1.30, the deformation temperature is 880-950 ℃, the roughing rolling biting speed is 0.12m/s, and the outlet speed of the roughing mill group 2 is 0.57 m/s; and (4) cutting the head and the tail of the rolled piece by using a head cutting flying shear 6.

(3) Rolling by a medium rolling mill set: after the rolled piece in the step (2) is rolled by the rough rolling mill set 2, and the rolled piece is subjected to head and tail cutting by flying shears, 6-pass short-stress-line intermediate rolling mill set 3 rolling is carried out, 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 deformation compression ratio of each pass is controlled to be 1.30, the deformation temperature is 850-900 ℃, the intermediate rolling biting speed is 0.57m/s, and the outlet speed of the intermediate rolling mill set is 2.68 m/s; and after rolling, the rolled piece is subjected to water cooling recovery and is subjected to flying shear head and tail cutting.

(4) Rolling by a finishing mill group: and (3) after rolling by the middle rolling mill set, performing water cooling and recovery by a water cooling box 7, performing head and tail cutting by a head and tail cutting flying shear 6 on the rolled piece in the step (3) by a 6-pass short stress line finishing rolling mill set 4, wherein 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 in the rolling process is 1.25, the deformation temperature is 800-900 ℃, the finish rolling biting speed is 2.68m/s, the outlet speed of the finishing rolling mill set is 10.24m/s, and the rolled piece is subjected to water cooling and recovery by the water cooling box 7 and head and tail cutting by the head and tail cutting flying shear 6.

(5) Rolling by a high-speed bar machine set: after the finish rolling in the step (4), performing water cooling and recovery on the rolled piece which is subjected to head and tail cutting by flying shears, and performing 2-pass high-speed bar machine set 14 rolling on the rolled piece, wherein a pass system is an oval-round pass system, guides and guards are arranged at the front and the rear of each rolling mill during rolling, the deformation compression ratio of each pass is controlled to be 1.25, the deformation temperature is 730-850 ℃, the diameter reduction gripping speed is 10.24m/s, the outlet speed of the high-speed bar machine set 14 is 16.0m/s, and the diameter of a finished product after the outlet of the high-speed bar machine set 14 is 16.0 mm; the bar rolled by the high-speed bar machine set 14 is controlled and cooled by the water cooling box 7.

(6) Cutting to length and steel feeding: after being cooled, the bars rolled by the high-speed bar machine set in the step (4) are subjected to fixed-length shearing by a fixed-length flying shear 11 after passing through a pinch roll 21 and a switch 22, the front bar after being sheared enters one path of a two-path guide groove 23, the rear bar enters the other path of the two-path guide groove, the front bar is forcibly braked in a rotating hub 16 through a tail clamping brake 15, the front bar automatically falls into a tooth groove of a cooling bed 5 after being braked by the rotation of the rotating hub 16, and the rear bar enters the rotating hub 16 through the other path of the two-path guide groove 23 and goes to the cooling bed 5 after being braked.

(7) Cooling by a cooling bed: after the bar material is sized on the cooling bed 5, the bar material runs in a tooth groove of the cooling bed 5 in a stepping mode, the stepping period of the cooling bed 5 is 1.05s, and when the bar material runs to an alignment roller way of the cooling bed 5, the bar material is cooled through a plurality of groups of blowing nozzles 28 below the cooling bed 5, so that the upper surface and the lower surface are uniformly cooled, and the bar material rolls. In this embodiment, the cooling bed controlled cooling device 20 includes 2 groups of blowing nozzles 28, the blowing nozzles 28 are water cooling nozzles, the blowing nozzles 28 in different positions of the 2 groups spray water, the interval between the blowing nozzles 28 in the same group is 0.2m to 0.5m, the interval between the blowing nozzles 28 in different groups is 0.5m to 3.0m, the water pressure of the blowing nozzles 28 is 0.2MPa to 1.0MPa, after cooling by the blowing nozzles 28, the blowing is performed by the compressed air nozzles, the interval between the compressed air blowing nozzles is 0.2m to 0.5m, the interval between the compressed air blowing nozzles and the blowing nozzles 28 is 0.5m to 1.0m, and when the bar runs to the cooling bed run-out roller table 10, the surface temperature of the bar is about 298 ℃.

TABLE 1 production parameter table for deformed steel bars of different specifications

TABLE 2 Cooling parameter table for cooling bed of deformed steel bars of different specifications

Finally, the above embodiments are only intended to illustrate the technical solutions of the present invention and not to limit the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all of them should be covered by the claims of the present invention.

Claims

1. A production method of a medium and large size bar is characterized by comprising the following steps: comprises the following steps of (a) carrying out,

heating: heating a steel billet to 900-1300 ℃;

rolling: rolling the heated steel billet, wherein the running speed of a rolled piece after rolling is 1.0-18.00 m/s;

cutting to length and steel feeding: carrying out fixed-length shearing on the rolled piece, and braking the fixed-length bar material subjected to fixed-length shearing to finish steel feeding;

and (3) cooling: the sized bar is run in a step-wise fashion and cooled.

2. The method of claim 1, wherein the step of heating comprises a step of forming a billet having a cross-sectional dimension of 150mm × 150mm to 200mm × 200mm, the billet being a square or rectangular billet.

3. A method for producing bars of medium to large format according to claim 2, characterized in that: the "rolling" step includes the following sub-steps,

rough rolling: rolling the heated billet, wherein the deformation compression ratio of each pass is controlled to be 1.20-1.45 in the rolling process, the deformation temperature is 880-1200 ℃, and the running speed of a rolled piece is 0.075 m/s-3.00 m/s;

intermediate rolling: rolling the rough-rolled piece, wherein the deformation compression ratio of each pass is controlled to be 1.20-1.40, the deformation temperature is 850-1100 ℃, and the running speed of the rolled piece is 1.0-10.00 m/s;

finish rolling: and rolling the rolled piece after the intermediate rolling, wherein the deformation compression ratio of each pass is controlled to be 1.20-1.40, the deformation temperature is controlled to be 800-1050 ℃, and the running speed of the rolled piece is 1.0-18.00 m/s.

4. A method for producing bars of medium to large format according to claim 3, characterized in that: in the rough rolling step, the heated billet is rolled in a horizontal and vertical alternative or flat roller rolling mode, 6 times of short stress line rolling is carried out on the square billet, and 5 times or 7 times of short stress line rolling is carried out on the rectangular billet;

in the step of 'intermediate rolling', 6-pass or 8-pass short stress line rolling is carried out on the rolled piece after the rough rolling is finished;

in the step of finish rolling, the rolled piece after the finish rolling is subjected to 6 times of short stress line rolling.

5. A method for producing bars of medium to large format according to claim 3, characterized in that: the rolling step also comprises the following sub-steps,

reducing rolling and dividing steps: and reducing the diameter of the rolled piece after finish rolling for 3-5 times, wherein the deformation compression ratio of each time is controlled to be 1.01-1.35, the deformation temperature is 730-950 ℃, and the running speed of the rolled piece is 1.0-18.0 m/s.

6. A method for producing bars of medium to large format according to claim 1, characterized in that: in the cooling step, the sized bar is fed onto a cooling bed and runs on the cooling bed in a stepping mode, when the bar runs to a roller bed aligned with the cooling bed, the bar is cooled on line through a water-cooling nozzle below the cooling bed, and an air blowing nozzle is arranged behind the water-cooling nozzle to blow dry the residual cooling water on the surface of the bar.

7. A large and medium size bar production system is characterized in that: the device comprises a heating unit, a rolling unit, a fixed-length shearing unit, a steel feeding unit and a cooling bed which are connected in sequence;

the rolling unit comprises a rough rolling unit and a middle rolling unit which are connected in sequence, and a high-speed finishing rolling unit or a reducing rolling unit is connected behind the middle rolling unit;

the running speed of the output rolled piece of the rolling unit is 1.0-18.0 m/s.

8. A large and medium size bar production system according to claim 7, wherein: the steel feeding unit is a skirtboard system or a high-speed steel feeding system, the high-speed finishing mill set is connected with the cooling bed through the high-speed steel feeding system, and the reducing rolling mill set is connected with the cooling bed through the skirtboard system;

the roughing mill group adopts the non-groove rolling or the groove rolling;

the hole pattern systems of the finishing mill group and the middle mill group are both oval-round hole pattern systems, and guides and guards are arranged at the front and the rear of each mill of the finishing mill group and the middle mill group.

9. A large and medium size bar production system according to claim 8, wherein: the heating unit is a walking beam type heating furnace or an electromagnetic induction heating device; the apron board system is a magnetic braking apron board, and the high-speed steel feeding system comprises a pinch roll, a double-way guide groove and a tail clamping brake.

10. A large and medium size bar production system according to claim 9, wherein: still include the packing unit, the packing unit is connected with the cold bed, and the packing unit is including the automatic binding device, the roll table of beating and the bundle collection rack that connect gradually.