CN111389906A - A method and system for producing medium and large size bars - Google Patents

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 iron and steel metallurgy industry. The production method includes the following steps: heating: heating the steel billet to 900°C-1300°C; rolling: rolling the heated steel billet, and the running speed of the rolled piece after rolling is 1.0m/s-18.00m/s; Ruler shearing and steel loading: Cut the rolled piece to length after rolling, brake the fixed-length bar after cut-to-length, and complete the steeling; Cooling: The fixed-length bar runs in a stepwise manner, Carry out cooling; the production system includes a heating unit, a rolling unit, a cut-to-length steel unit and a cooling bed that are connected in sequence. The present invention directly performs fixed-length shearing after the rolling is completed, and adopts the method of high-speed upper steel or magnetic braking apron for braking, so that the braking distance is shortened, the bar is not cut by the double-length, and the double-length is not required. The length of the cooling bed has a small cooling bed area, which effectively reduces the equipment and processes, shortens the length of the production line, and reduces investment.

Description

A method and system for producing medium and large size bars

technical field

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

Background technique

As one of the important products in the steel industry, rebar and high-quality steel bars are widely used in construction, machinery and metal products industries. In recent years, the output has continued to increase, reaching 268 million tons in 2017, which accounted for 25.57% of China's total steel production.

Please refer to Figure 1, Figure 2, Figure 13 and Figure 14. The production process of ordinary high-quality steel bars mainly includes: heating furnace heating, rolling in rough and medium finishing mills, and flying shearing head and tail after rolling mills, before and after finishing mills Water tank cooling, diameter reduction unit rolling, controlled cooling after diameter reduction, double-scale flying shear shearing, cooling bed, fixed-length cold shearing and shearing, non-fixed-length collection, cross-over gantry collection, counting, alignment, baling and labeling , weighing and other processes. When producing rebar, the split rolling production process can be used. There are also some steel mills that use high-speed steel feeding systems to produce rebar and ordinary round steel bars. The main production processes mainly include: heating furnace heating, rolling in rough, medium and finishing mills, and flying shearing head and tail after rolling mills, finishing rolling. Water tank cooling before and after the unit, rolling of high bar finishing mill, controlled cooling after high bar finishing mill, double-length flying shear shearing, cooling bed, fixed-length cold shearing, non-fixed-length collection, cross-cross gantry collection, Counting, aligning, baling and labeling, weighing and other processes.

Whether it is an ordinary bar production process or a high-speed steel production process, there are the following shortcomings: 1. The production process is complex. After multi-unit rolling, the rolled piece needs to be cut by double-length, cooled by cooling bed, cut to length, Non-fixed-length collection, counting, aligning, bundling, labeling, weighing and other processes; 2. The production line has many and complex equipment, which is prone to failure; 3. The rolled piece needs to be processed in multiple processes, and a single continuous casting billet is produced, which is prone to irregularities. 4. When using the split rolling production process to produce rebar, due to process limitations, it is impossible to achieve more accurate negative deviation rolling; 5. When using the split rolling production process to produce rebar, the The material type requirements are more stringent, and the amount of cutting head is increased by 0.5% to 0.7% compared with the conventional bar; 6. When the rebar is produced by the split rolling production process, the product is prone to burrs, which easily lead to folding or crack defects, and the yield is low. ;The defects of the billet are exposed after being cut, forming surface defects; after cutting, it needs to be twisted and needs to be equipped with a twist guide; 7. Due to the limitation of production technology, there will be surface defects when the high-speed steel feeding system produces high-quality steel, and only the thread can be rolled. Steel, ordinary carbon steel and other steels that require general surface quality; 8. Due to the limitation of production technology, the distance between the double-foot flying shear and the cooling bed after rolling is large, generally about 80m, the length of the rolling line is large, the workshop area is large, and the investment is large. higher;

Aiming at the problems of complex system, high failure rate, long production line and high investment in the current bar production, the present invention provides a large-size bar production line in an ultra-short process and a low-cost and high-efficiency bar production method, which can greatly shorten the length of the production line , Reduce the complexity of the production system, reduce the equipment failure rate, reduce the investment cost, improve the production stability, improve the utilization rate of the rolling mill, and improve the economic benefits.

SUMMARY OF THE INVENTION

In view of this, the purpose of the present invention is to provide a method and system for producing medium and large size bars, simplify the production system for medium and large size bars, and improve the production efficiency of medium and large size bars.

In order to achieve the above purpose, the present invention provides the following technical solutions: a method for producing medium and large-sized bars, comprising the following steps: heating: heating the steel billet to 900°C to 1300°C; rolling: rolling the heated steel billet, The running speed of the rolled piece after rolling is 1.0m/s ~ 18.00m/s; cut to length and steel: cut the rolled piece to a fixed length, and cut to a fixed length bar after cut to length Brake to complete the upper steel; cooling: the fixed-length bar runs in a step-by-step manner for cooling.

Optionally, in the "heating" step, the section size 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 sub-steps: rough rolling: rolling the heated steel billet, controlling the deformation and compression ratio of each pass to be 1.20 to 1.45, and the deformation temperature to be 880 ° C to 880 ° C during the rolling process. 1200℃, the rolling speed is 0.075m/s～3.00m/s; medium rolling: rolling the rough rolling, controlling the deformation and compression ratio of each pass to be 1.20～1.40, the deformation temperature The temperature is 850℃～1100℃, and the running speed of the rolling piece is 1.0m/s～10.00m/s; Finish rolling: Roll the rolling piece after the intermediate rolling, and control the deformation and compression ratio of each pass to be 1.20～ 1.40, the deformation temperature is 800℃～1050℃, and the rolling speed is 1.0m/s～18.00m/s.

Optionally, in the "rough rolling" sub-step, the heated steel billet is rolled by means of horizontal and vertical alternating or flat roll rolling. Pass or 7 passes of short stress line rolling; in the "intermediate rolling" sub-step, 6 passes or 8 passes of short stress line rolling are performed on the rolled piece after rough rolling; in the "finishing rolling" sub-step, 6 passes of short stress line rolling were performed on the rolled piece after the intermediate rolling was completed.

Optionally, in the "rolling" step, the following sub-steps are also included, and the diameter-reducing rolling is sub-step: reducing the diameter of the finished rolling piece, performing 3-5 passes of the reducing rolling, and rolling In the process, the deformation and compression ratio of each pass is controlled to be 1.01 to 1.35, the deformation temperature to be 730°C to 950°C, and the rolling speed to be 1.0m/s to 18.0m/s.

Optionally, in the "cooling" step, the fixed-length bars are loaded onto the cooling bed, and run on the cooling bed in a step-by-step manner. The bar is cooled online, and the air blowing nozzle is set after the water cooling nozzle to dry the residual cooling water on the surface of the bar.

A medium and large-sized bar production system, comprising a heating unit, a rolling unit, a cut-to-length unit, an upper steel unit and a cooling bed connected in sequence; the rolling unit includes a rough rolling group, a medium rolling group connected in sequence , the middle rolling unit is connected with a high-speed finishing rolling unit or a reducing rolling unit; the running speed of the rolling unit outputting the rolling stock is 1.0m/s～18.0m/s;

Optionally, the upper steel unit is a skirt system or a high-speed steel system, the high-speed finishing rolling unit is connected to the cooling bed through the high-speed steel system, and the diameter reducing rolling unit is connected to the cooling bed through the skirt system. ; The rough rolling mill adopts no-pass rolling or pass rolling; the pass systems of the finishing rolling mill and the intermediate rolling mill are all elliptical-circular pass systems, and the finishing rolling mill and the Guide guards are provided before and after each rolling mill of the middle rolling mill.

Optionally, the heating unit is a walking beam heating furnace or an electromagnetic induction heating device; the skirt system is a magnetic brake skirt, and the high-speed steel upper system includes pinch rollers, dual-channel guide grooves and clamps. tail brake.

Optionally, it also includes a baling unit, the baling unit is connected to the cooling bed, and the baling unit includes an automatic baling device, a baling roller table and a bundle collection platform connected in sequence. The beneficial effects of the present invention are:

(1) The present invention directly performs fixed-length shearing after the rolling is completed, and does not go through double-length shearing, thereby reducing equipment and processes; (2) Adopting high-speed upper steel or the combination of braking apron and magnetic apron for braking , the braking distance of the bar is shortened, the length of the production line is shortened, and the investment is reduced; (3) the use of direct sizing, no need for a cooling bed with a double length, the cooling bed area is small, the length of the production line is shortened, and the investment is reduced; (4) in the cooling Nozzles are used on the bed to control the cooling of bars, which improves the cooling efficiency of the cooling bed and improves product quality; (5) There is no need to configure fixed-length cold shears, cross-span inspection benches and other equipment in the finishing process, and there are fewer production line equipment and low failure rates. ; (6) The product has a wide range of production specifications, and can produce all rebar bars within the specification range of Φ16.0mm～Φ50.0mm and all round steel bar products within the specification range of Φ16.0mm～Φ90.0mm; (7) Due to the use of The single rolling method has high dimensional accuracy of the product; (8) Negative deviation rolling of rebar can be realized to improve the metal yield; (9) Due to the use of direct sizing, combined with the previous high-speed continuous casting and rolling process or no The head rolling process realizes single-line gapless production, high production line yield, high production line hourly output, and high production line rolling mill efficiency.

Other advantages, objects, and features of the present invention will be set forth in the description that follows, and will be apparent to those skilled in the art based on a study of the following, to the extent that is taught in the practice of the present invention. The objectives and other advantages of the present invention may be realized and attained by the following description.

Description of drawings

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be preferably described in detail below with reference to the accompanying drawings, wherein:

Figure 1 is a schematic diagram of the layout of a traditional slitting bar production line;

Figure 2 is a schematic diagram of the layout of a traditional high-speed bar production line;

Figure 3 is a schematic diagram of the layout of the reducing rolling production line;

Figure 4 is a schematic diagram of the layout of the high-speed finishing rolling production line;

Figure 5 is a schematic diagram of the layout of the high-speed steel loading system;

Figure 6 is a schematic view of the bar on the conveying roller table during magnetic braking;

Fig. 7 is the schematic diagram of bar magnetic braking apron descending;

Fig. 8 is the schematic diagram of bar magnetic braking skirt rising;

Figure 9 is a schematic diagram of the bar on the cooling bed during magnetic braking;

Figure 10 is a schematic structural diagram of a magnetic braking apron;

Figure 11 is a schematic structural diagram of a cooling bed controlled cooling device;

12 is a schematic diagram of the arrangement of an automatic baling device, a baling roller table and a bundling collection platform;

Figure 13 is the temperature cloud diagram of the cross-section of the cooling bed bar on the traditional specification bar;

Figure 14 is the temperature cloud diagram of the cross-section of the cooling bed bar under the traditional specification bar.

Reference number:

Heating furnace 1, rough rolling unit 2, intermediate rolling unit 3, finishing rolling unit 4, cooling bed 5, cutting head flying shear 6, water cooling box 7, double foot flying shear 8, cooling bed inlet roller table 9, cooling bed output roller 10, fixed-length flying shears 11, finished product collection device 12, waste collection device 13, high-speed bar finishing mill 14, clamp tail brake 15, rotating hub 16, continuous casting billet connection and electromagnetic induction heating device 17, diameter reduction Unit 18, Magnetic Brake Skirt 19, Cooling Bed Control Device 20, Pinch Roller 21, Switch 22, Dual Channel Guide 23, Bar 24, Conveyor Roller 25, Water and Cold Water Tank 26, Purge Main Pipe 27. Purge nozzle 28, automatic baling device 29, baling roller table 30, baling collection stand 31.

Detailed ways

The embodiments of the present invention are described below through specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments are only used to illustrate the basic idea of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

Among them, the accompanying drawings are only used for exemplary description, and represent only schematic diagrams, not physical drawings, and should not be construed as limitations of the present invention; in order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings will be omitted, The enlargement or reduction does not represent the size of the actual product; it is understandable to those skilled in the art that some well-known structures and their descriptions in the accompanying drawings may be omitted.

The same or similar numbers 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 are terms “upper”, “lower”, “left” and “right” , "front", "rear" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must be It has a specific orientation, is constructed and operated in a specific orientation, so the terms describing the positional relationship in the accompanying drawings are only used for exemplary illustration, and should not be construed as a limitation of the present invention. situation to understand the specific meaning of the above terms.

Example 1

Please refer to Figure 3 to Figure 12, taking the production of Φ40mm rebar as an example, refer to Table 1 and Table 2 to select production parameters. The production process sequence includes: electromagnetic induction heating of headless continuous casting billet, rolling in rough rolling mill, flying shearing head and tail after rough rolling, rolling in intermediate rolling mill, flying shearing head and tail after intermediate rolling, water cooling after intermediate rolling, Flying shearing head and tail before reducing diameter, rolling by reducing unit, water cooling after reducing diameter, fixed-length flying shears, magnetic brake skirt plate braking upper cooling bed, fixed-length cooling bed cooling, cooling bed controlled cooling, bar counting , bundling, aligning, weighing and finished product delivery.

The production implementation process is as follows:

(1) Endless billet connection and heating: The continuous casting billet connection and electromagnetic induction heating device 17 are used to connect and heat the endless continuous casting billet. After heating, the surface temperature of the continuous casting billet is 930℃±30℃ to ensure The bite temperature of the rough rolling unit 2 is not lower than 900°C; in this embodiment, the slabs are connected by the slab connection device of a headless welder, and the front and rear slabs are welded, and the slabs are transported to the For the rough rolling unit, the section of the slab is 165mm×165mm, and the conveying speed of the slab is 0.28m/s;

(2) Rough rolling unit 2 rolling and rough rolling after rough rolling: In this embodiment, a horizontal and vertical alternating rolling mill is used to perform 6 passes of short stress line rough rolling on the billet after the connection and heating of the endless billets in step (1). Mill rolling can be used without pass rolling and pass rolling. When pass rolling is used, the rough rolling mill 2 is a box-box-ellipse-round pass system. Guide guards are installed before and after the stand rolling mill, and there are cutting head flying shears 6 behind the rough rolling unit. During the rolling process, the deformation and compression ratio of each pass is 1.30, the deformation temperature is 880 ° C ~ 950 ° C, and the rough rolling bite speed is 0.28. m/s, the outlet speed of the roughing mill is 1.35m/s; after rolling, the cutting head and flying shears are used to cut the head and tail.

(3) Rolling in the middle rolling group 3: After rough rolling in step (2), the rolling stock after the cutting head and flying shear 6 cutting the head and tail is subjected to 4 passes of short stress line rolling in the middle rolling group. The pass system is an elliptical-circular pass system. There are guides before and after each rolling mill. During the rolling process, the deformation and compression ratio of each pass is controlled to be 1.30, the deformation temperature is 850 ° C ~ 900 ° C, and the bite speed of the middle rolling is controlled. It is 1.35m/s, and the exit speed of the middle rolling unit is 3.79m/s;

(4) Rolling by reducing unit 18: After the intermediate rolling in step (3), the rolling stock after water cooling and recovery, and after flying shearing of the head and tail, is subjected to 2-pass two-roller reducing unit rolling, and the pass The system is an ellipse-round pass system. There are guides before and after each rolling mill during rolling. During the rolling process, the deformation and compression ratio of each pass is controlled to be 1.25, the deformation temperature is 730℃～850℃, and the diameter reduction bites The 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 rolled by the reducing unit 18 is controlled and cooled.

(5) Cut-to-length and upper steel: After the bar rolled by the reducing unit 18 in step (4) is cooled by the water-cooling box 7, it is cut to a fixed-length of 12m by the fixed-length flying shears 11. After cutting to length, the former steel is accelerated first, and the acceleration distance is 18.0m. After the acceleration, the former bar and the second bar are separated by a distance. At this time, the former bar passes through the magnetic braking skirt. The plate 19 is quickly braked, and when the magnetic brake skirt 19 receives the braking signal, the magnetic coil is energized to form a magnetic skirt. The sequence of actions is as follows:

(a) The magnetic braking apron 19 is consistent with the conveying roller table 25, and the bar 24 is gradually inclined and slid to the side of the magnetic braking apron 19 during operation;

(b) The magnetic braking skirt 19 moves downward to form a drop with the conveying roller table 25, and the bar slides along the magnetic braking skirt 19 to the cooling bed side;

(c) The magnetic braking skirt 19 moves upward, forming a height difference with the conveying roller table 25 to prevent the next bar 24 from slipping into the magnetic braking skirt 19, and the bar 24 on the magnetic braking skirt 19 moves along the The magnetic brake skirt 19 continues to slide toward the cooling bed 5 side;

(d) The magnetic braking skirt 19 returns to its original position, the former bar 24 falls into the tooth slot of the cooling bed 5, and moves step by step. After receiving the braking signal of the latter bar 24, repeat For the above actions, the braking period of the magnetic braking apron 19 is 2.15s under the conditions of this technological parameter, and the acceleration during braking is (-0.6g)～-(0.7g).

(6) Cooling bed cooling: After the fixed-length bar 24 is placed on the cooling bed 5, it runs in a stepwise manner in the tooth slot of the cooling bed 5. The step cycle of the cooling bed 5 is 2.15s, and it runs until the cooling bed is aligned. During the roller table, cooling is carried out by the cooling bed control cooling device 20 under the cooling bed. In order to ensure uniform cooling of the upper and lower surfaces, the bar 24 is rolled while cooling. In this embodiment, the cooling bed cooling control device 20 includes a water and cold water tank 26 , and two groups of purging nozzles 28 , the purging nozzles 28 are water-cooled nozzles, and the group of purging nozzles 28 and the water-cooled water tank 26 are communicated through the purging main pipeline 27 . The spacing between the purging nozzles 28 in the same group is 0.2m-0.5m, the spacing between the purging nozzles 28 in different groups is 0.5-3.0m, the purging water pressure is 0.2MPa-1.0MPa, and after multiple groups of purging nozzles 28 After purging and cooling, it is purged by compressed air nozzles. The spacing between the air purging nozzles is 0.2m to 0.5m, and the spacing between the air purging nozzles and the water cooling nozzles is 0.5m to 1.0m. The bar 24 runs to the cooling bed output roll. At pass 10, the bar surface temperature was about 296°C.

(7) Bundle collection: at the end of the cooling bed 5, an automatic bundling device 29, a bundling roller table 30 and a bundle collection stand 31 are set, and the bars 24 are counted, bundled, labeled and weighed. It is transported to the finished product warehouse by overhead crane and horizontal car, or directly out of the warehouse by car.

Example 2

Please refer to Figure 3 to Figure 12, take the production of Φ16mm rebar as an example, select the production parameters with reference to Table 1 and Table 2, the production process sequence includes: electromagnetic induction heating of endless continuous casting billet, rough rolling mill rolling, after rough rolling Flying shear head and tail, intermediate rolling mill rolling, water-cooled flying shear head and tail after intermediate rolling, finishing mill rolling, water cooling after finishing rolling, flying shear head and tail before reduction, reducing mill rolling, reduction Rear water cooling, fixed-length flying shears, magnetic brake apron braking upper cooling bed, fixed-length cooling bed cooling, controlled cooling on the cooling bed, bar counting, baling, alignment, weighing and finished product delivery.

The production implementation process is as follows:

(1) Endless billet connection and heating: The continuous casting billet connection and electromagnetic induction heating device 17 are used to connect and heat the endless continuous casting billet. After heating, the surface temperature of the continuous casting billet is 930℃±30℃ to ensure The bite temperature of rough rolling unit 2 is not lower than 900 ℃; when the billets need to be connected, use a billet connecting device such as a headless welder to weld the front and rear billets, and transport the billets to the rougher through the roller table. In the rolling group, the section of the slab is 165mm×165mm, and the conveying speed of the slab is 0.12m/s.

(2) Rolling in rough rolling unit 2: The billet after connecting and heating the endless billet in step (1) is subjected to 6-pass short stress line rough rolling unit 2 rolling by using a horizontal and vertical alternating rolling mill, and no-pass rolling can be used. Rolling or pass rolling, when pass rolling is used, there are guides at the front and rear of each rolling mill. Pass rolling is adopted in this embodiment, and the rough rolling unit 2 is a box-box-ellipse-round pass system. The rough rolling unit 2 is provided with a cutting head flying shear 6, and the cutting head flying shears 6 are used for rough rolling. After the rolling, the head is cut; the deformation and compression ratio of each pass in the rolling process is 1.30, the deformation temperature is 880 ° C ~ 950 ° C, the bite speed of rough rolling is 0.12m/s, and the exit speed of rough rolling unit 2 is 0.57m/ s; After the rolling stock is rolled, cut the head and fly shear 6 to cut the head and tail.

(3) Rolling in the intermediate rolling group 3: rolling in the intermediate rolling group 3 with 6 passes of short stress lines for the rolling stock after the rough rolling group 2 rolling in step (2), and after the head and tail of the flying shearing, are rolled. The pass system is an ellipse-circular pass system. There are guides before and after each rolling mill. During the rolling process, the deformation and compression ratio of each pass is controlled to be 1.30, and the deformation temperature is 850°C to 900°C. The entry speed is 0.57m/s, and the exit speed of the middle rolling group 3 is 2.68m/s;

(4) Rolling by finishing rolling unit 4: After rolling by the intermediate rolling unit 3 in step (3), after being water-cooled and recovered, and by flying shearing head and tail, the rolling stock is subjected to a 6-pass short stress line finishing rolling unit 4. During rolling, the pass system is an ellipse-circular pass system. There are guides before and after each rolling mill. During the rolling process, the deformation and compression ratio of each pass is 1.25, and the deformation temperature is 800℃～900℃. , the bite speed of finishing rolling is 2.68m/s, and the exit speed of finishing rolling unit 4 is 10.24m/s;

(5) Rolling by the reducing unit 18: 2 passes of rolling by the reducing unit 18 are performed on the rolling stock after being rolled by the finishing rolling unit 4 in step (4), after being water-cooled and recovered, and after the head and tail are sheared by flying , In this embodiment, the diameter reducing unit 18 is a two-roller reducing unit. The pass system is an elliptical-circular pass system. During rolling, there are guides before and after each rolling mill. During the rolling process, the deformation and compression ratio of each pass is controlled to be 1.25, the deformation temperature is 730 ° C ~ 850 ° C, and the diameter is reduced. The bite speed is 10.24m/s, the outlet speed of the reducing unit 18 is 16.0m/s, and the diameter of the finished bar after the reducing outlet is 16.0mm;

(6) Cut-to-length and steel loading: the bar rolled by the reducing unit 18 in step (5) is cooled by the water-cooling box 7, and then cut to a fixed length of 12 m by the fixed-length flying shears 11. , after the fixed-length shearing, the former bar is accelerated first, and the acceleration distance is 18.0m. After the acceleration, the former bar and the second bar are separated by a distance. At this time, the former bar is magnetically restrained. The moving skirt 19 is quickly braked. When the magnetic braking skirt 19 receives the braking signal, the magnetic coil is energized to form a magnetic skirt. The sequence of actions is as follows:

(a) The magnetic braking apron 19 is consistent with the conveying roller table 25, and the bar 24 is gradually inclined and slid to the side of the magnetic braking apron 19 during operation;

(b) The magnetic braking skirt 19 moves downward to form a drop with the conveying roller table 25, and the bar slides along the magnetic braking skirt 19 to the cooling bed side;

(c) The magnetic braking skirt 19 moves upward, forming a height difference with the conveying roller table 25 to prevent the next bar 24 from slipping into the magnetic braking skirt 19, and the bar 24 on the magnetic braking skirt 19 moves along the The magnetic brake skirt 19 continues to slide toward the cooling bed 5 side;

(d) The magnetic braking skirt 19 returns to its original position, the former bar 24 falls into the tooth slot of the cooling bed 5, and moves step by step. After receiving the braking signal of the latter bar 24, repeat For the above actions, the braking period of the magnetic braking apron 19 is 1.05s under the conditions of this technological parameter, and the acceleration during braking is (-0.6g)～-(0.7g).

(7) Cooling bed cooling: After the fixed-length bar is placed on the cooling bed 5, it runs in the form of stepping in the tooth slot of the cooling bed 5. The step cycle of the cooling bed 5 is 1.05s, and it runs to the alignment roller of the cooling bed 5. During the passage, cooling is performed by the cooling bed cooling device 20 under the cooling bed. In order to ensure uniform cooling of the upper and lower surfaces, the bar 24 is rolled while being cooled. In this embodiment, the cooling bed control cooling device 20 includes two groups of purging nozzles 28, the purging nozzles 28 are water-cooled nozzles, the spacing between the purging nozzles 28 in the same group is 0.2m-0.5m, and the purging nozzles in different groups are The distance between the 28 is 0.5-3.0 m, and the water pressure for purging the nozzle 28 is 0.2 MPa-1.0 MPa. After cooling by multiple groups of purging nozzles 28, the bar is blown by compressed air nozzles, the distance between the air purging nozzles is 0.2m to 0.5m, the distance between the air purging nozzles and the water cooling nozzles is 0.5m to 1.0m, and the bars run. When the cooling bed leaves the roller table 10, the surface temperature of the bar is about 298°C.

(8) Bundle collection: at the end of the cooling bed 5, an automatic bundling device 29, a bundling roller table 30 and a bundle collection stand 31 are provided, and the bars 24 are counted, bundled, labeled and weighed. Afterwards, it will be transported to the finished product warehouse by overhead crane and horizontal car, or directly out of the warehouse by car.

Example 3

Please refer to Figure 3 to Figure 12, taking the production of Φ40mm rebar as an example, refer to Table 1 and Table 2 to select production parameters. The production process sequence includes: electromagnetic induction heating of endless continuous casting billet, rolling in rough rolling mill, flying shearing head and tail after rough rolling, rolling in intermediate rolling mill, water cooling after intermediate rolling, flying shearing before high-speed bar rolling Head and tail, high-speed bar mill rolling, water cooling after high-speed bar mill rolling, fixed-length flying shear, high-speed steel loading system, controlled cooling on cooling bed, bar counting, bundling, alignment, weighing and finished product delivery library.

The production implementation process is as follows:

(1) Endless billet connection and heating: The continuous casting billet connection and electromagnetic induction heating device 17 are used to connect and heat the endless continuous casting billets. The two billets are welded, and the billets are transported to the rough rolling unit through the roller table. After heating, the surface temperature of the continuous casting billet is 930°C ± 30°C to ensure that the bite temperature of the rough rolling unit 2 is not lower than 900°C ; The section of the slab is 165mm×165mm, and the conveying speed of the slab is 0.28m/s;

(2) Rough rolling unit 2 rolling: Use a horizontal and vertical alternating rolling mill to perform 6 passes of short stress line rough rolling unit rolling on the billet after step (1) endless billet connection and heating, and no-pass rolling can be used. or pass rolling. In this embodiment, pass rolling is adopted, and the rough rolling unit is a box-box-ellipse-round pass system. Guide guards are arranged before and after each rolling mill, and a cutting head flying shear is arranged after the rough rolling unit 2. 6. During the rolling process, the deformation and compression ratio of each pass is 1.30, the deformation temperature is 880℃～950℃, the bite speed of rough rolling is 0.28m/s, the outlet speed of rough rolling unit is 1.35m/s, and the rolled piece is roughened. After rolling, the head and tail are cut by flying shear 6.

(3) Rolling in the middle rolling group 3: After rough rolling in step (2), the rolling stock after the cutting head and flying shears 6 cuts the head and tail is subjected to 4 passes of short stress line rolling in the middle rolling group 3, rolling. The time pass system is an elliptical-circular pass system. There are guides before and after each rolling mill. During the rolling process, the deformation and compression ratio of each pass is controlled to be 1.30, and the deformation temperature is 850℃～900℃. The speed is 1.35m/s, and the exit speed of the middle rolling mill is 3.79m/s. The rolled piece after rolling by the middle rolling mill is cooled by water cooling box 7 and recovered, and the head and tail are cut by cutting head and flying shear 6.

(4) High-speed bar mill rolling: 2 passes of high-speed bar mill 14 rolling are performed on the rolled piece after intermediate rolling in step (3), water cooling and recovery, and flying shearing of the head and tail. The system is an ellipse-round pass system. There are guides before and after each rolling mill during rolling. During the rolling process, the deformation and compression ratio of each pass is controlled to be 1.25, the deformation temperature is 730℃～850℃, and the diameter reduction bites The speed is 10.24m/s, the exit speed of the high-speed bar unit 14 is 16.0m/s, and the diameter of the finished product after the exit of the high-speed bar unit 14 is 40.0mm. cool down.

(5) Cut-to-length and steel loading: After cooling the bar rolled by the high-speed bar unit in step (4), it is fixed by the fixed-length flying shear 11 after passing through the pinch roller 21 and the switch 22. After cutting, the former bar enters one of the two-way guide grooves 23, and the latter bar enters the other way. After the movement, the rotating hub 16 automatically falls into the tooth slot of the cooling bed 5, and the latter rod enters the rotating hub 16 through the other way of the double-channel guide groove 23, and goes to the cooling bed 5 after braking.

(6) Cooling bed cooling: After the fixed-length bar is placed on the cooling bed 5, it runs in the form of stepping in the tooth slot of the cooling bed 5. The step cycle of the cooling bed 5 is 2.15s, and it runs to the alignment roller of the cooling bed 5. During the passage, cooling is carried out by multiple groups of purging nozzles 28 under the cooling bed 5. In order to ensure uniform cooling of the upper and lower surfaces, the bar is rolled. In this embodiment, the cooling bed control cooling device 20 includes two groups of purging nozzles 28, the purging nozzles 28 are water-cooled nozzles, the two groups of purging nozzles 28 at different positions spray water, and the distance between the purging nozzles 28 in the same group It is 0.2m to 0.5m, the spacing between different groups of purging nozzles 28 is 0.5 to 3.0m, and the water pressure of the purging nozzles 28 is 0.2MPa to 1.0MPa. Carry out purging, the spacing between the air purging nozzles is 0.2m-0.5m, and the spacing between the air purging nozzles and the purging nozzles 28 is 0.5m-1.0m, when the bar runs to the cooling bed output roller table 10, the surface of the bar is The temperature is about 296°C.

(7) Bundle collection: at the end of the cooling bed 5, an automatic bundling device 29, a bundling roller table 30 and a bundle collection stand 31 are provided, and the bars 24 are counted, bundled, labeled and weighed. Afterwards, it will be transported to the finished product warehouse by overhead crane and horizontal car, or directly out of the warehouse by car.

Example 4

Please refer to Figure 3 to Figure 12, take the production of Φ16mm rebar as an example, select the production parameters with reference to Table 1 and Table 2, the production process sequence includes: electromagnetic induction heating of endless continuous casting billet, rough rolling mill rolling, after rough rolling Flying shear head and tail, rolling in intermediate rolling mill, water cooling after intermediate rolling, flying shearing head and tail before finishing rolling, rolling in finishing mill, water cooling after finishing rolling, flying shearing head and tail before high-speed bar rolling, high speed Bar rolling, water cooling after high-speed bar rolling, fixed-length flying shears, high-speed steel loading system, controlled cooling on cooling bed, bar counting, baling, alignment, weighing and finished product delivery;

The production implementation process is as follows:

(1) Endless billet connection and heating: The continuous casting billet connection and electromagnetic induction heating device 17 are used to connect and heat the endless continuous casting billets. The two billets are welded, and the billets are transported to the rough rolling unit through the roller table. After heating, the surface temperature of the continuous casting billet is 930°C ± 30°C to ensure that the bite temperature of the rough rolling unit 2 is not lower than 900°C ; The section of the slab is 165mm×165mm, and the conveying speed of the slab is 0.12m/s;

(2) Rough rolling unit 2 rolling: Use a horizontal and vertical alternating rolling mill to perform 6 passes of short stress line rough rolling unit rolling on the billet after step (1) endless billet connection and heating, and no-pass rolling can be used. or pass rolling. In this embodiment, pass rolling is adopted, and the rough rolling unit is a box-box-ellipse-round pass system. Guide guards are arranged before and after each rolling mill, and a cutting head flying shear is arranged after the rough rolling unit 2. 6. Use the cutting head flying shear 6 to cut the rolled piece after rough rolling; the deformation and compression ratio of each pass in the rolling process is 1.30, the deformation temperature is 880 ℃ ~ 950 ℃, and the rough rolling bite speed is 0.12m/s , the outlet speed of the rough rolling unit 2 is 0.57m/s; after the rolling stock is rolled, the cutting head and the flying shear 6 cut the head and tail.

(3) Rolling in the intermediate rolling group: After rolling in the rough rolling group 2 in step (2), the rolling stock after the flying shearing head and tail is rolled in the intermediate rolling group 3 with 6 passes of short stress lines, and the rolling is carried out. The time pass system is an elliptical-circular pass system. There are guides before and after each rolling mill. During the rolling process, the deformation and compression ratio of each pass is controlled to be 1.30, and the deformation temperature is 850℃～900℃. The speed is 0.57m/s, and the exit speed of the middle rolling group is 2.68m/s; after the rolling stock is rolled, it is water-cooled and recovered, and the head and tail are fly-cut.

(4) Finishing rolling mill rolling: After rolling by the intermediate rolling mill in step (3), after being water-cooled by the water cooling box 7 and recovered, and by the cutting head flying shear 6, the rolling stock after cutting the head and tail is subjected to 6 passes of short stress Line finishing rolling unit 4 is rolled, the pass system is elliptical-circular pass system during rolling, there are guides before and after each rolling mill, the deformation and compression ratio of each pass in the rolling process is 1.25, and the deformation temperature is 800 ℃～900℃, the bite speed of finishing rolling is 2.68m/s, the exit speed of finishing rolling unit is 10.24m/s, after rolling, the rolled piece is cooled by water cooling box 7 and cut off by cutting head and flying shear 6.

(5) High-speed bar mill rolling: 2 passes of high-speed bar mill 14 rolling are performed on the rolled piece after finishing rolling in step (4), water cooling and recovery, and flying shearing of the head and tail. The system is an ellipse-round pass system. There are guides before and after each rolling mill during rolling. During the rolling process, the deformation and compression ratio of each pass is controlled to be 1.25, the deformation temperature is 730℃～850℃, and the diameter reduction bites The speed is 10.24m/s, the exit speed of the high-speed bar unit 14 is 16.0m/s, and the diameter of the finished product after the exit of the high-speed bar unit 14 is 16.0mm; Controlled cooling.

(6) Cut-to-length and steel loading: After cooling the bar rolled by the high-speed bar unit in step (4), it is fixed by the fixed-length flying shear 11 after passing through the pinch roller 21 and the switch 22. After cutting, the former bar enters one of the two-way guide grooves 23, and the latter bar enters the other way. After the movement, the rotating hub 16 automatically falls into the tooth slot of the cooling bed 5, and the latter rod enters the rotating hub 16 through the other way of the double-channel guide groove 23, and goes to the cooling bed 5 after braking.

(7) Cooling bed cooling: After the fixed-length bar is placed on the cooling bed 5, it runs in the form of stepping in the tooth slot of the cooling bed 5. The step cycle of the cooling bed 5 is 1.05s, and it runs to the alignment roller table of the cooling bed 5. During the cooling process, cooling is carried out through multiple groups of purging nozzles 28 under the cooling bed 5. In order to ensure uniform cooling of the upper and lower surfaces, the bar is rolled. In this embodiment, the cooling bed control cooling device 20 includes two groups of purging nozzles 28, the purging nozzles 28 are water-cooled nozzles, and the two groups of purging nozzles 28 at different positions spray water, and the distance between the purging nozzles 28 in the same group is It is 0.2m to 0.5m, the spacing between different groups of purging nozzles 28 is 0.5 to 3.0m, and the water pressure of the purging nozzles 28 is 0.2MPa to 1.0MPa. For purging, the spacing between the compressed air purging nozzles is 0.2m-0.5m, the spacing between the compressed air purging nozzles and the purging nozzles 28 is 0.5m-1.0m, when the bar runs to the cooling bed output roller table 10, the bar The surface temperature is about 298°C.

(8) Bundle collection: at the end of the cooling bed 5, an automatic bundling device 29, a bundling roller table 30 and a bundle collection stand 31 are provided, and the bars 24 are counted, bundled, labeled and weighed. Afterwards, it will be transported to the finished product warehouse by overhead crane and horizontal car, or directly out of the warehouse by car.

Table 1 Production parameters of rebar bars with different specifications

Table 2 Cooling parameter table of cooling bed for rebar bars of different specifications

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be Modifications or equivalent replacements, without departing from the spirit and scope of the technical solution, should all be included in the scope of the claims of the present invention.

Claims (10)

1. a medium and large size bar production method, is characterized in that: comprise the steps, Heating: heating the billet to 900℃~1300℃; Rolling: Roll the heated billet, and the rolling speed after rolling is 1.0m/s~18.00m/s; Cut-to-length and steel-loading: cut-to-length on the rolled piece, brake the cut-to-length bar to complete steel loading; Cooling: The cut-to-length bar runs in steps for cooling. 2 . The method for producing medium and large size bars according to claim 1 , wherein in the “heating” step, the section size of the billet is 150mm×150mm to 200mm×200mm, and the billet is a square billet or a rectangular billet. 3 . 3. A method for producing medium and large size bars according to claim 2, characterized in that: in the "rolling" step, the following steps are included, Rough rolling: Roll the heated billet. During the rolling process, the deformation and compression ratio of each pass is controlled to be 1.20~1.45, the deformation temperature is 880℃~1200℃, and the rolling speed is 0.075m/s~3.00m/ s; Medium rolling: Roll the rough rolled piece. During the rolling process, the deformation and 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 rolling piece is 1.0m/s~10.00 m/s; Finishing rolling: Roll the rolling stock after intermediate rolling. During the rolling process, control the deformation and compression ratio of each pass to be 1.20~1.40, the deformation temperature to be 800℃~1050℃, and the running speed of the rolling stock to be 1.0m/s~18.00 m/s. 4. A method for producing medium and large size bars according to claim 3, characterized in that: in the "rough rolling" sub-step, the heated billet is rolled by means of alternating horizontal and vertical rolling or flat roll rolling. , 6 passes of short stress line rolling for square billets, and 5 passes or 7 passes of short stress line rolling for rectangular billets; In the "intermediate rolling" sub-step, 6 passes or 8 passes of short stress line rolling are performed on the rolled piece after rough rolling; In the sub-step of "finishing rolling", 6 passes of short stress line rolling is performed on the rolling stock after the intermediate rolling is completed. 5. A method for producing medium and large size bars according to claim 3, characterized in that: in the "rolling" step, the following steps are also included, Steps of reducing diameter rolling: reduce diameter rolling on the finished rolling piece, reduce diameter rolling for 3 to 5 passes, control the deformation and compression ratio of each pass to be 1.01 to 1.35 during the rolling process, and the deformation temperature to be 730℃~950℃, the rolling speed is 1.0m/s~18.0m/s. 6. A method for producing medium and large size bars according to claim 1, characterized in that: in the "cooling" step, the bars after the sizing are placed on a cooling bed, and the cooling bed is operated in a stepwise manner, When running until the cooling bed is aligned with the roller table, the bar is cooled online through the water cooling nozzle under the cooling bed, and an air blowing nozzle is set after the water cooling nozzle to dry the residual cooling water on the surface of the bar. 7. A medium and large size bar production system, characterized in that it comprises a heating unit, a rolling unit, a cut-to-length unit, an upper steel unit and a cooling bed connected in sequence; The rolling unit includes a rough rolling group and an intermediate rolling group connected in sequence, and a high-speed finishing rolling group or a reducing rolling group is connected after the intermediate rolling group; The running speed of the output rolling stock of the rolling unit is 1.0m/s~18.0m/s. 8. A medium and large-sized bar production system according to claim 7, characterized in that: the upper steel unit is a skirt plate system or a high-speed upper steel system, and the high-speed finishing mill is connected with the high-speed steel upper system through the high-speed steel upper system. The cooling bed is connected, and the reducing rolling unit is connected with the cooling bed through the skirt plate system; The rough rolling unit adopts no-pass rolling or pass rolling; The pass systems of the finishing rolling mill and the intermediate rolling mill are both elliptical-circular pass systems, and guides are provided before and after each rolling mill of the finishing rolling mill and the intermediate rolling mill. 9. A medium and large size bar production system according to claim 8, characterized in that: the heating unit is a walking beam type heating furnace or an electromagnetic induction heating device; the skirt plate system is a magnetic braking skirt plate , the high-speed steel feeding system includes pinch rollers, dual-channel guide grooves and a pinch tail brake. 10. A medium and large size bar production system according to claim 9, characterized in that: it further comprises a packing unit, the packing unit is connected with a cooling bed, and the packing unit comprises an automatic baling device, a baling roller connected in sequence Road and bundle collection racks.

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