CN107838193A - Combined type cold rolling line - Google Patents

Abstract

A composite cold rolling line includes a feeding unit, a first rolling unit connected downstream of the feeding unit, an annealing and rust removal unit connected downstream of the first rolling unit, and a A pickling unit connected downstream of the annealing and rust removal unit, a second rolling unit connected downstream of the pickling unit, and a stripping unit connected downstream of the second rolling unit. The first cold rolling mill can perform preliminary rolling before the annealing and pickling process, which not only reduces the thickness required for the second rolling, but also can continuously produce large quantities of high-yield products. Cold-rolled thin hard plate steel coils, and because the black steel coils after preliminary rolling can reduce the amount of rust by 30 to 70%, the number and length of rust removal equipment can be reduced. In addition to reducing equipment costs, it can also reduce The use and emission of sand blasting and acid liquid achieve the environmental protection performance of energy saving and waste reduction.

Description

Composite cold rolling line

technical field

The present invention relates to a composite cold rolling line, in particular to a composite cold rolling system for continuously and massively producing cold-rolled thin and hard steel coils with a minimum thickness of 0.25 mm from the input black steel coils. Wire.

Background technique

Referring to Figure 1, the traditional stainless steel cold rolling process is to use the black steel coil F1 as the material, and use the hot rolling annealing and pickling line A to make the NO.1 steel coil F2 after annealing, sandblasting and pickling processes, and then The NO.1 steel coil F2 is reciprocated and multi-pass rolled by the 20-roller cold rolling mill of the cold rolling line B until the NO.1 steel coil F2 is rolled to the target thickness, which is cold-rolled thin hard plate Steel coil F3. Cold-rolled thin and hard plate coil F3 can produce 2D steel coil F4, 2B steel coil F5, F6 after other processes such as cold-rolled annealing and pickling line C, quenching and tempering rolling line D and tension leveling line E... ...and other high value cold rolled stainless steel products.

The aforementioned cold rolling process is sent to the hot-rolled annealing and pickling line A in the black steel coil F1. After the annealing process, the oxide scale on the surface will be thickened, and the subsequent mechanical rust removal process such as sandblasting and pickling must be strengthened. Wait for the chemical rust removal process to remove the scale on the surface of the steel coil, so it is necessary to increase the sandblasting machine and increase the sandblasting speed, increase the length of the pickling tank and increase the acid concentration, resulting in equipment costs, sandblasting and acid consumption and subsequent increases in waste disposal costs. And because there is no significant difference in thickness between the incoming black skin coil F1 and the outgoing NO. help.

The NO.1 steel coil F2 enters the subsequent cold rolling line B process, which uses a single-seat 20-roller cold rolling mill for reciprocating rolling, and the number of rolling passes required will result in a higher output per unit time. However, this kind of reciprocating cold rolling mill cannot provide a large amount of cold rolling due to the large reduction rate required for the production of thin steel plates, the high probability of strip breakage, the large number of rolling passes, and the long rolling time required. Thin hard plate steel coil F3. In addition, this kind of reciprocating rolling mill needs to establish tension by coiling. Therefore, the head and tail sections of the steel coil will each have a length of about 6-8m for coiling, and the off-gauge that has not been rolled must be cut off, and the material loss of the cut section will cause Even if this problem is welded to the guide tape before the coil preparation line of the previous process, there will still be a 3m long off-gauge, resulting in an increase in the on-line cost of the coil preparation line and the guide tape cost.

In addition, because the traditional cold-rolled annealing and pickling line C and the cold rolling mill are independent production lines, the black skin incoming steel coil F1 is uncoiled, rolled, hot-rolled, annealed, and pickled, and the coiling is NO .1 Steel coil F2, while NO.1 steel coil F2 needs to be uncoiled on-line in cold rolling production and rolled after completion of rolling delay to obtain cold-rolled thin and hard plate steel coil F3, so much waste of hot-rolled annealing line collection Coil and cold rolling mill on-line unwinding time, resulting in reduced production efficiency.

Contents of the invention

The object of the present invention is to provide a composite cold rolling line with low production cost, high product output rate, and continuous production to provide a large number of cold rolled thin and hard steel coils with a thickness of up to 0.25 mm.

The composite cold-rolling line of the present invention is used to continuously make cold-rolled thin-hard steel coils from the input black-skinned steel coils; A feed unit in which the coil is a steel strip and is conveyed downstream, a first rolling unit comprising two or three first cold rolling mills arranged adjacent to each other and downstream of the feed unit, a Downstream of the first rolling unit, an annealing and derusting unit for annealing and mechanical derusting treatment of the steel strip, and an annealing and derusting unit downstream of the annealing and derusting unit for pickling and chemical derusting of the steel strip A pickling unit for rust treatment, a second rolling unit comprising five second cold rolling mills arranged adjacent to each other and downstream of said pickling unit, and a second rolling unit following said second rolling unit Downstream return unit.

Preferably, in the aforementioned composite cold rolling line, the first cold rolling mill of the first rolling unit is used to continuously roll the passing steel strip, and the first cold rolling mill The maximum total rolling reduction rate is 50%.

Preferably, in the aforementioned composite cold rolling line, the second cold rolling mill of the second rolling unit is used to continuously roll the passing steel strip, and the second cold rolling mill The maximum total rolling reduction rate is 75%.

Preferably, the aforesaid composite cold rolling line, wherein the annealing and descaling unit includes a furnace zone connected downstream of the first rolling unit with a horizontal chain structure, and a crushing unit connected downstream of the furnace zone A rust machine, at least one sandblasting zone downstream of the rust breaker, and a grinding brush roll downstream of the sandblasting zone.

Preferably, the aforementioned compound cold-rolling line, wherein the pickling unit includes a first pickling zone connected downstream of the grinding brush roll, a downstream of the first pickling zone connected with the The first pickling zone uses a second pickling zone for pickling with different solutions, and a first detector connected downstream of the second pickling zone.

Preferably, the aforementioned composite cold-rolling line, wherein the feed unit includes a feed area, and a first welding joint downstream of the feed area for welding different black steel coils machine.

Preferably, the above compound cold rolling line, wherein the material returning unit includes an alkali cleaning area connected downstream of the second rolling unit, a second detector connected downstream of the alkali cleaning area , and a discharge area continuous downstream of the second detector.

Preferably, the aforementioned composite cold rolling line, wherein the composite cold rolling line also includes a material return unit located between the pickling unit and the second rolling unit, the material return unit includes a continuous In the stripping area downstream of the first detector of the pickling unit, and a second welding machine connected downstream of the stripping area, when the first detector detects the quality of a section of steel strip passing through When it is not up to standard, the steel strip will be guided to the stripping area, and the substandard section of steel strip will be cut off, and the second welding machine will be used to weld the cut off substandard section Two lengths of steel belt before and after the steel belt.

Preferably, the aforementioned composite cold rolling line, wherein the composite cold rolling line also includes a material accumulation unit, the material accumulation unit includes a first welding machine connected to the feeding unit and the first The first accumulating area between the rolling units, the second accumulating area connected between the first rolling unit and the annealing and descaling unit, and the second accumulating area connected between the pickling unit and the stripping unit The third material accumulation area in the material return section, a fourth accumulation area between the second welding machine connected to the material return unit and the second rolling unit, and a material accumulation area connected to the material return unit The second detector and the fifth accumulation area in the discharge area.

The beneficial effect of the present invention is that: the first cold rolling mill can perform preliminary rolling before the annealing and pickling process, which not only reduces the thickness required for the second rolling to reduce broken strips Therefore, it can continuously produce high-yield cold-rolled thin-hard steel coils in large quantities, and because the black-skinned steel coils after the initial rolling can reduce the amount of scale by 30-70%, it can reduce the descaling equipment In addition to reducing the cost of equipment, it can also reduce the use and discharge of sandblasting and acid liquid, so as to achieve the environmental performance of energy saving and waste reduction.

Description of drawings

Figure 1 is a production line diagram illustrating the conventionally known stainless steel cold rolling process;

Fig. 2 is a production line diagram illustrating an embodiment of the composite cold rolling line of the present invention; and

Fig. 3 is a flowchart illustrating the process flow of this embodiment.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

Referring to Fig. 2, an embodiment of the composite cold rolling line 1 of the present invention is used to continuously make cold-rolled thin and hard plate steel coils (Cold Rolled coil) in large quantities from the input black skin coil (Blackcoil), and the composite The cold-rolling line 1 includes a feeding unit 2, a first rolling unit 3, an annealing and descaling unit 4, a pickling unit 5, a stripping unit 6, and a second unit from the upstream to the downstream of the production line. Rolling unit 7, a material returning unit 8, and a material accumulating unit 9 arranged between the aforementioned units and used for connection according to production speed matching. The feeding unit 2 includes a feeding area 21 , and a first welding machine 22 downstream of the feeding area 21 . In this embodiment, the feeding area 21 has two uncoiling stations 211, and each uncoiling station 211 is equipped with a steel coil storage device, a steel coil trolley, a hanging mandrel uncoiler and a steel coil unwinding station. , Leveling, cutting equipment. The first welding machine 22 is a laser automatic welding machine produced by Guild International Company, the model is MEL Laser Welder. The first welding machine 22 uses an optical fiber laser system, so it only needs to connect an optical fiber cable between the laser power supply and the laser welding head without other consumables. Direct rolling without opening the worker rolls, so there is almost no off-gauge material loss in the output steel coil.

The first rolling unit 3 comprises two first cold rolling mills 31 arranged adjacent to each other and downstream of the first welding mill 22 of the feeding unit 2 . The first cold rolling mill 31 is a serial cold rolling mill, the model is T-Sendzimir Z-type inserts ZR 613A-52, the maximum production speed at the entrance is 200mpm, the average production speed at the entrance is 63mpm, and the maximum production speed at the exit is 200mpm , the export average production speed is 125mpm, and the maximum total rolling reduction rate of the two first cold rolling mills 31 is set to 50%, and the black steel coil is rolled according to different steel types or rolling reduction rate It can reduce the amount of scale by 30-70%, can help the downstream annealing and rust removal unit 4 and pickling unit 5, reduce the number and length of rust removal equipment, reduce the pickling concentration and shorten the pickling time. Each first cold rolling mill 31 includes a quick roll changing device to ensure that the production line will not be interrupted during welding and worker roll replacement. The first cold rolling mill 31 uses water-soluble rolling oil, which has the characteristics of good cooling effect and low oil cost. In addition, in order to cope with the thick and large amount of scale on the steel strip, the filter system is a filter cloth filter system, which can not only maintain the cleanliness of the rolling oil, but also cost less than the cartridge filter system. It should be noted that the number of the first cold rolling mills 31 in this embodiment is two, but in other variations of this embodiment, the number of the first cold rolling mills 31 can also be three .

The annealing and descaling unit 4 sequentially includes a furnace zone 41 connected to the downstream of the first cold rolling mill 31, a rust breaker 42, a sandblasting zone 43, and a grinding brush roll 44 from upstream to downstream. . The furnace zone 41 is a horizontal chain structure, and has two radiation preheating sections, four gas heating sections, and five cooling sections. The main control computer of the furnace area 41 has APN code settings, which can correspond to different steel types and thicknesses, and automatically adjust to the required annealing parameter conditions (Annealing Parameters) to avoid the risk of human error. The sandblasting area 43 includes four sandblasting machines. The grinding brush roller 44 uses two sets of steel brush rollers and back rollers. The brush rollers contact the surface of the steel strip, which can not only remove the upper and lower surface scales, but also reduce the surface roughness, which can effectively improve the NO.1 steel strip surface. The surface fineness of the volume.

The pickling unit 5 includes a first pickling zone 51 , a second pickling zone 52 , and a first detector 53 successively downstream of the grinding brush roll 44 from upstream to downstream. The first pickling zone 51 has two sulfuric acid tanks, and the second pickling zone 52 has four mixed acid tanks using nitric acid and hydrofluoric acid, and five stages of water washing sections. The water washing section has 2 stages of water spray cleaning, 2 stages of scrubbing machine cleaning and 1 stage of hot air drying. The first detector 53 is an automatic detection system, which can immediately judge whether the steel strip has defects that are not conducive to rolling, and choose whether to return the material in advance of the material return unit 6, so as to avoid poor product quality and subsequent second Risk of strip breakage in the rolling unit 7.

The material return unit 6 includes a material return area 61 downstream of the first detector 53 , and a second welding machine 62 downstream of the material return area 61 . The stripping area 61 has winding mandrels, tension rollers, shears, steering rollers, interlining equipment, sleeve loading, steel coil unloading vehicles, and steel coil bundling, weighing and storage equipment. The model and function of the second welding machine 62 and the first welding machine 22 are the same.

The second rolling unit 7 includes five second cold rolling mills 71 downstream of the second welding mill 62 of the stripping unit 6 . The type and equipment of the second cold rolling mill 71 are the same as those of the first cold rolling mill 31, so as to facilitate the sharing of parts and reduce the amount of spare parts, the difference is that the sum of the five second cold rolling mills 71 is the maximum The total rolling reduction rate is 75%, and the maximum production speed at the entrance is 200 mpm, the average production speed at the entrance is 125 mpm, the maximum production speed at the exit is 600 mpm, and the average production speed at the exit is 500 mpm. The second cold rolling mill 71 is designed to have a switchable water-soluble and mineral-based rolling oil system, and general products are produced with water-soluble rolling oil, especially steel grades without high-gloss requirements (such as pan 400 series, 200 series) to reduce production costs; high-quality products are turned to mineral rolling oil for production. The rolling oil filtration system adopts different filtering methods according to different rolling oil types and product quality requirements. Water-soluble rolling oil filter cloth filter system; mineral rolling oil filter core filter system. In addition, the rolling mill is equipped with AGC (Automatic Gauge Feedback Control) and AFC (Automatic Shape Detection Feedback Control) systems, which can provide coil products with accurate thickness and good shape.

The material returning unit 8 includes an alkali washing area 81 connected to the second cold rolling mill 71 , a second detector 82 , and a discharge area 83 sequentially from upstream to downstream. The alkali washing area 81 has sections such as spray alkali washing, brush washing, hot water washing and final hot air drying. The second detector 82 is an automatic detection system of the same type as the first detector 53 . The discharge area 83 has two winding stations 831, and each winding station 831 is the same as the stripping area 61 and has winding mandrels, tension rollers, shears, steering rollers, interlining equipment, Socket loading, coil unloading vehicles, and coil binding, weighing and storage equipment.

The accumulation unit 9 includes a first accumulation area 91 connected between the first welding machine 22 of the feeding unit 2 and the first rolling unit 3, and a first accumulation area 91 connected to the first rolling unit. 3 and the second accumulation area 92 between the annealing and derusting unit 4, a third accumulation area 93 connected between the pickling unit 5 and the stripping area 61 of the stripping unit 6, and a continuous The fourth accumulation zone 94 between the second welder 62 of the material stripping unit 6 and the second rolling unit 7, an alkali cleaning zone 81 connected to the stripping unit 8 and the second The fifth accumulation area 95 between the detectors 82.

Referring to Fig. 2 and Fig. 3, the manufacturing process of described composite cold-rolling line 1 is as follows: the black skin steel coil that imports is arranged in the steel coil storage equipment of described feeding area 21, and described black skin steel coil is hot-rolled Produced and unannealed and pickled stainless steel coils. After unwinding the black-skinned steel coils into plate-shaped steel strips, one of the uncoiling stations 211 transports the steel strips downstream along the production line, and when the black-skinned steel coils are used up, another unwinding station The coil station 211 will then unwind another roll of black steel coil into a steel strip and transport it, and the head and tail of the two steel strips will be connected by the first welding machine 22 . Then the steel strip passes through the two first cold rolling mills 31 to carry out the rolling operation with a maximum reduction ratio of 50%, thereby reducing the thickness of the steel strip, and rolling can improve the thickness of the steel strip. The scale on the surface is broken, and the amount of scale can be reduced by 30-70% according to different steel types and rolling-down rates. In addition, the weld bead formed by the first welding machine 22 on the two steel strips has high flatness and uniform strength, so the weld bead can pass through the first cold rolling mill 31 without opening the work roll. Rolling directly can improve the production efficiency of the production line and avoid the occurrence of strip breakage during rolling.

The steel strip after the first rolling will be sent into the furnace area 41, and in the radiation preheating section, the heat drawn from the gas heating section will be radiated and heated. The section heats the steel strip to an annealing temperature of nearly 1200 degrees Celsius. The first four cooling sections use air as the cooling medium to reduce the temperature to about 150 degrees Celsius, while the fifth cooling section uses water cooling to reduce the steel strip to a maximum temperature of 70 degrees Celsius, and finally Then it goes through a hot air drying section to remove moisture from the surface of the steel strip. The rust breaker 42 uses rollers to bend the steel strip, forcing the scale on the surface of the steel strip to break and peel off, and can improve the shape of the steel strip. Each sandblasting machine in the sandblasting area 43 is equipped with two sandblasting wheels respectively on the upper and lower opposite sides of the steel strip, and the steel strip surface scale is broken and crushed to remove the steel strip by throwing sand balls. Most of the rust on the outside surface. The grinding brush roller 44 uses two sets of steel brush rollers to brush off the scale on the upper and lower surfaces of the steel strip, and can reduce the surface roughness of the steel strip, thereby improving the fineness of the surface. Since the amount of scale is reduced by the preliminary rolling of the steel strip through the first cold rolling mill 31 , the quantity of the annealing and descaling units 4 and the length of the production line can be reduced.

After the steel strip is sent into the pickling unit 5, it is pickled sequentially through the first pickling zone 51 and the second pickling zone 52, and finally passes through the five-stage water washing in the second pickling zone 52. section to ensure that the steel strip surface is completely free of residual acid. The finished product of steel strip after pickling is NO.1 steel strip, but for the convenience of explanation, it is still collectively referred to as steel strip. It should be noted that since the steel strip is initially rolled by the first cold rolling mill 31 to reduce the amount of scale, it can reduce the pickling concentration and the time of pickling operation, and because the rust breaking machine 42 forces the rust scale of the steel strip to break and peel off, so the sulfuric acid easily erodes the base material of the steel strip from the rust scale cracks during pickling, thereby increasing the efficiency of pickling and derusting. The steel strip after pickling will be judged by the first detector 53 whether there are defects that are not conducive to subsequent rolling. roll, and cut off the defective section with a shearing machine, and then use the second welding machine 62 to weld and join the two steel strips at the front and back of the defective section, and continue the follow-up operation.

The steel strip passing through the stripping area 61 will pass through the five second cold rolling mills 71 in order to carry out the rolling operation with a maximum total reduction rate of 75%, so that the steel strip is rolled to the target thickness and manufactured. Get the required cold-rolled thin and hard plate coils. The second cold rolling mill 71 is equipped with an automatic gauge feedback control (AGC) system and an automatic shape detection feedback control (AFC) system, so as to facilitate rolling the steel strip into a cold-rolled steel strip with precise thickness and good shape. Thin rigid board. Finally, the cold-rolled thin hard plate passes through the alkali cleaning zone 81 to remove water-soluble or mineral rolling oil on the surface, and is sent to the discharge zone after the output quality is confirmed by the second detector 82 83 coils are collected as cold-rolled thin and hard plate steel coils. In addition, when the production line needs to be shut down for a short time, the steel strips can be temporarily stored in the first, second, third, fourth and fifth accumulation areas 91 , 92 , 93 , 94 , 95 .

The following table 1 is the actual production capacity estimation table of this embodiment. It can be seen from the table 1 that the finished product of this case can indeed reach the target thickness of less than 1 mm, and the minimum thickness can reach 0.25 mm.

Table I

Through the first cold rolling mill 31, the steel strip can be pre-compressed before the annealing and pickling operation, so as to reduce the thickness required for the subsequent rolling operation, thereby preventing the steel strip from being compressed in the second rolling operation. In the rolling unit 7, the strip breakage rate increases due to the excessive reduction rate of the rolled sheet. When the steel strip passes through the first cold rolling mill 31 and the second cold rolling mill 71, it is conveyed in one direction without rolling back and forth, so that the production line can be continuously produced and the utilization rate of the production line can be improved and production efficiency. In addition, the preliminary rolling of the first cold rolling mill 31 can also reduce the amount of scale on the steel strip, thereby reducing the number and length of descaling equipment, and can reduce the pickling concentration and the time of pickling operations, thereby reducing Material costs for equipment, blasting and acid.

In summary, the first cold rolling mill 31 can perform preliminary rolling before the annealing and pickling process, which not only reduces the thickness required for the second rolling and improves the product yield, but also The black-skinned steel coil after preliminary rolling can reduce the amount of scale by 30-70%, thereby reducing the number and length of descaling equipment, reducing the pickling concentration and shortening the pickling time, so the purpose of the present invention can indeed be achieved .

Claims (9)

1. A composite cold-rolling line, which is used to continuously make cold-rolled thin and hard steel coils from the input black steel coils; it is characterized in that: the composite cold-rolling line includes a A feed unit for unwinding coils into strips and conveying downstream, a first rolling unit comprising two or three first cold rolling mills arranged next to each other and downstream of said feed unit, a An annealing and derusting unit connected downstream of the first rolling unit and performing annealing and mechanical derusting treatment on the steel strip, an annealing derusting unit connected downstream of the annealing and derusting unit and pickling the steel strip A pickling unit for chemical descaling treatment, a second rolling unit comprising five second cold rolling mills arranged adjacent to each other and downstream of the pickling unit, and a second rolling mill following the second rolling mill The return unit downstream of the unit. 2. The composite cold rolling line according to claim 1, characterized in that: the first cold rolling mill of the first rolling unit is used to continuously roll the passing steel strip, and the The maximum total reduction ratio of the first cold rolling mill is 50%. 3. The composite cold rolling line according to claim 1, characterized in that: the second cold rolling mill of the second rolling unit is used to continuously roll the passing steel strip, and the The maximum total reduction ratio of the second cold rolling mill is 75%. 4. The composite cold-rolling line according to claim 1, characterized in that: the annealing and derusting unit comprises a horizontal chain type structure and is connected to the downstream furnace zone of the first rolling unit, and a furnace zone connected to the downstream of the first rolling unit. A rust breaker downstream of the furnace zone, at least one sandblasting zone downstream of the rust breaker, and a grinding brush roll downstream of the sandblasting zone. 5. The composite cold rolling line according to claim 4, characterized in that: the pickling unit comprises a first pickling zone connected downstream of the grinding brush roll, a first pickling zone connected downstream of the first pickling unit A second pickling zone downstream of the washing zone and using a different solution from the first pickling zone for pickling, and a first detector connected downstream of the second pickling zone. 6. The compound cold-rolling line according to claim 5, characterized in that: the feed unit includes a feed area, and a downstream of the feed area is used to mix different black steel The first welding machine for welding rolls. 7. The composite cold-rolling line according to claim 6, characterized in that: the stripping unit includes an alkali cleaning zone connected to the downstream of the second rolling unit, an alkali cleaning zone connected to the downstream of the second rolling unit A second detector downstream of the second detector, and a discharge area continuous downstream of the second detector. 8. The compound cold-rolling line according to claim 7, characterized in that: the compound cold-rolling line also comprises a material return unit located between the pickling unit and the second rolling unit, the The material return unit includes a material return area connected to the downstream of the first detector of the pickling unit, and a second welding machine connected to the downstream of the material return area. When the first detector detects When the quality of a section of steel strip passing through is substandard, the steel strip will be guided to the stripping area, and the substandard section of steel strip will be cut off. The second welding machine is used to weld the cut off section. Except the two sections of steel strips before and after the section of steel strips that do not meet the standard. 9. The composite cold-rolling line according to claim 8, characterized in that: the composite cold-rolling line also includes a material accumulation unit, and the material accumulation unit includes a first A first accumulation area between the welding machine and the first rolling unit, a second accumulation area connected between the first rolling unit and the annealing descaling unit, and a second accumulation area connected between the pickling unit unit and the third material accumulation area in the material return section of the material return unit, a fourth accumulation area between the second welding machine of the material return unit and the second rolling unit, and a continuous In the second detector of the material return unit and the fifth accumulation area of the discharge area.