CN115254953B - Cast-rolled 3004 checkered plate and preparation method thereof - Google Patents

Abstract

The invention provides a manufacturing method of cast-rolled 3004 checkered plates, which comprises the following preparation processes: taking a cast-rolled 3004 aluminum alloy coil as a blank, reserving a processing rate of 30-35% for cold rolling to an intermediate thickness, incompletely annealing, performing cold rolling embossing when the coil is cooled to 60-80 ℃, and uniformly flowing metal in a deformation area during embossing on a neutral surface by controlling cold rolling parameters so as to obtain good embossing quality; then spraying and brushing cleaning oil, adsorbing by a vacuum liquid suction roller, cleaning with water, sweeping, drying, and finally carrying out incomplete annealing; the invention solves the technical problems of easy pattern skew, offset and incomplete pattern when the cast-rolled 3004 aluminum alloy blank is embossed with poor plasticity, and simultaneously adopts an incomplete annealing mode to prevent the coarse grain phenomenon of Mn element segregation easy to be generated during recrystallization when the cast-rolled 3004 aluminum alloy is rapidly cooled; finally, compared with the hot rolling method, the checkered plate realizes the great cost reduction.

Description

A cast-rolled 3004 patterned plate and its preparation method

Technical Field

The invention belongs to the technical field of aluminum alloy processing, and particularly relates to a cast-rolled 3004 patterned plate and a preparation method thereof.

Background Art

The sources of aluminum alloy patterned plates on the market are mainly hot-rolled and cast-rolled.

The hot rolling method generally undergoes smelting, casting, ingot milling, ingot homogenization, preheating, and hot rolling; the casting and rolling method, also known as continuous casting and rolling, refers to the process of directly "rolling" liquid metal into semi-finished products or finished products. The fundamental difference from other continuous ingot casting methods is that its crystallizer is two rotating casting rollers with cooling, and the liquid metal must complete the two processes of solidification and rolling between the roll gaps of the two rollers, and it is completed in a very short area (50-70mm) in a very short time of about 2 to 3 seconds. Liquid metal is formed into billets or materials at one time, which shortens the production process, simplifies the production process, and saves a lot of equipment investment and energy consumption. Its equipment cost is only 1/3 of that of hot-rolled billets. Due to the omission of secondary heating and the reduction of rolling passes, the energy consumption is only 40% of the traditional hot rolling production method. More importantly, the hot rolling process has a longer cycle of billets, from smelting to milling, to homogenization heat treatment, and finally to the production of hot rolled billets, which generally takes at least half a month; while the casting and rolling process from smelting to the production of cast and rolled billets can be obtained in only 48 hours. Compared with the hot rolling process, the casting and rolling process has many advantages: because the casting and rolling process is to complete the two processes of casting and rolling on one device at the same time, it saves multiple processes such as ingot heating, billet opening and hot rolling compared to the hot rolling process. At the same time, it reduces the remelting of waste and saves a lot of electricity; it saves the ingot milling, reduces the head and tail cutting after hot rolling, and greatly improves the yield rate; the equipment is simple and centralized, with low investment, small footprint and low production cost; it can be produced continuously and stably, simplifying the production process, shortening the production cycle, reducing the number of people in production, greatly improving the production efficiency, and facilitating automation. In other words, the casting and rolling process has very obvious cost advantages and fast supply advantages compared with the hot rolling process.

However, the cooling rate of the casting and rolling process is 100-200℃/s, while the cooling rate of the hot-rolled ingot is about 2-3℃/s. Under the condition of rapid cooling, the Mn element in the cast-rolled strip is strongly supersaturated in aluminum, and the degree of intracrystalline segregation and solid solution is greater than that of the semi-continuously cast hot-rolled ingot. The Mn element dissolved in the solid solution not only strengthens the bonding force between atoms, but also reduces the free diffusion coefficient of atoms. Therefore, the thermal activation energy required for the formation and growth of new crystal nuclei during annealing heating, that is, the recrystallization temperature, increases. At the same time, the deformation structure, casting structure, and recrystallization structure coexist inside the cast-rolled strip, and the structure is complex. The deformation storage energy obtained under the same cold deformation amount is small. When heated isothermally with the hot-rolled strip, the energy cannot be fully released. Therefore, the required recrystallization temperature after cold deformation is higher than that of the hot-rolled billet; in addition, the dislocation density and point defect amount of the cast-rolled strip after cold deformation are not as good as those of the hot-rolled billet. The number of recrystallization nuclei during annealing is small, and the recrystallization softening is insufficient. Compared with the two, the plasticity difference is large, and the plasticity of the casting and rolling method is poor.

3004 aluminum alloy belongs to Al-Mn alloy series, and is a typical alloy in this series, with (Mn) 1.0%-1.5%, (Mg) 0.8%-1.3%; 3004 aluminum alloy in GB/T3190-2008 "Chemical Composition of Deformed Aluminum and Aluminum Alloys" has the advantages of both Al-Mn and Al-Mg alloys, with medium strength, excellent corrosion resistance and deep drawing. It is a non-heat-treatable strengthening alloy, and the performance of the finished product can only be controlled by work hardening and annealing. 3004 aluminum alloy is widely used and is a typical rust-proof aluminum alloy. Its strength is higher than that of 3003 aluminum alloy, with excellent forming performance and good corrosion resistance. It is often used to manufacture parts with higher strength requirements than 3003 aluminum alloy. The most important thing is that the source of recycled 3004 aluminum alloy is very wide, such as the alloy of our common cans is 3004 alloy. In fact, the aluminum processing industry is making unremitting technical research to effectively digest the 3004 can waste on the market. In order to reduce costs, many aluminum processing companies in the market are actively developing and applying cast-rolled 3004. There are also rumors that there are attempts to use cast-rolled 3004 for aluminum alloy patterned plates, but all ended in failure. This is because many manufacturers only see the advantages of the quick and low-cost cast-rolling method, but do not fully realize the many technical difficulties faced by the use of cast-rolled 3004 in the development of aluminum alloy patterned plates:

1. The Mn content in the cast-rolled 3004 strip is 1.0-1.5%. Under rapid cooling conditions, according to the Al-Mn alloy equilibrium phase diagram, its solidification process has the following characteristics: (1) The liquidus slope is very small, and the isothermal crystallization interval is very wide. (2) The vertical crystallization interval between the liquidus and the solidus is very small, only 0.5-1.0℃. (3) The solid solubility of manganese in aluminum varies greatly and decreases sharply with the decrease in temperature. In addition, the casting and rolling production process has a rapid cooling rate, which has reached 100-200℃/s, which is about 2 orders of magnitude faster than the conventional semi-continuous casting technology. Therefore, there is obvious intragranular segregation in the high-Mn 3004 alloy cast-rolled plate, that is, there is a significant difference in the Mn element concentration inside and outside the crystal. When the finished product is annealed, the low-manganese area will first nucleate and generate recrystallized grains. When the temperature continues to rise to the high-manganese area where recrystallization can occur, the grains in the low-manganese area have already grown, resulting in different sizes of recrystallized grains. The conventional approach to solve the problem of coarse grains is to perform a sufficient homogenization heat treatment process at the beginning of cold rolling. The homogenization temperature is generally selected as: 0.9~0.95Tm, Tm is the temperature when the ingot begins to melt, and the homogenization temperature of 3004 ingot is generally above 530℃. In fact, high-temperature homogenization heat treatment is a heating and heat preservation process lasting 30~40h, with high energy consumption and cost; but if high-temperature homogenization heat treatment is not performed, the coarse grains will cause serious bending orange peel during the later annealing process; that is to say, the primary problem of casting and rolling 3004 in the later stage of making patterned plates is that the bending surface quality cannot be guaranteed.

2. The influence of poor plasticity of cast and rolled plates on the embossing quality of patterned plates, such as insufficient pattern rib height, distorted patterns, positional offset, and incomplete pattern ribs, which make it difficult to ensure the quality of patterns during embossing. The plastic forming of cold-rolled embossing is carried out in the deformation zone, and tension and rolling speed are the main parameters affecting the quality of embossing. Tension can reduce the rolling force, expand the flat strip to prevent deviation, and at the same time change the stress of the metal in the deformation zone from three-way compressive stress to two-way compressive stress and one-way tensile stress. The tensile stress not only limits the lateral expansion, but also promotes the longitudinal extension. Rolling theory believes that the metal in the deformation zone flows uniformly only in the neutral plane, and the flow in the front and rear sliding zones is uneven. Due to the existence of front sliding during rolling, excessive front tension will increase the front sliding value; excessive rear tension will increase the rear sliding value. Both of them destroy the uniform deformation of the neutral plane, resulting in quality defects such as distorted patterns and positional offset. The rough structure of the cast-rolled strip pattern plate is relatively loose. When subjected to high axial pressure in the deformation zone, it is compressed to a greater extent, and the metal used to fill the pattern grooves in the height direction is relatively insufficient; the structure of the coarse grains after recrystallization annealing has poor embossing coordination, slow metal flow rate, and excessively fast rolling speed results in the metal being thrown out of the rolling roller without fully filling the pattern grooves. Therefore, the pattern ribs are not full.

3. The aluminum powder and aluminum ash of cast-rolled patterned plates are much more serious than those of hot-rolled plates. If the aluminum powder remaining on the surface is not cleaned thoroughly, it will seriously affect the surface quality. In addition, the surface of the patterned plate is difficult to blow clean after cleaning due to the protruding patterns. Therefore, the cleaning process of conventional hot-rolled patterned plates cannot guarantee the cleaning quality of this project.

Cast-rolled 3004 has always been used to produce patterned plates. While ensuring that the final patterned plates are comparable to the technical level of hot-rolled aluminum alloy patterned plates at home and abroad, it also achieves a significant reduction in upstream processing costs. At the same time, it also provides a good solution for the recycling and reuse of 3004 waste such as cans on the market. These are the directions that aluminum processing companies are exploring.

Summary of the invention

In view of the shortcomings of the prior art, the present invention provides a cast-rolled 3004 patterned plate and a preparation method thereof, which can achieve a significant reduction in cost compared with the production of patterned plates by hot rolling without high-temperature homogenization heat treatment, and can produce 3004 patterned plates with the same quality as hot-rolled patterned plates through optimized control of a series of embossing processes, annealing processes and cleaning processes.

The technical solution of the present invention is as follows:

A cast-rolled 3004 pattern plate, the composition of the cast-rolled 3004 pattern plate includes the following components in weight percentage: Si=0.15%-0.25%, Fe=0.45%-0.55%, Cu=0.14%-0.2%, Mn=1.02%-1.15%, Mg=0.95%-1.1%, Cr≤0.05%, Zn≤0.15%, Ti=0.015%-0.025%, other inevitable single elements≤0.05%, total≤0.15%, and the balance is Al.

A method for preparing a cast-rolled 3004 patterned plate, wherein a cast-rolled aluminum alloy coil having a first-grade grain size, good surface quality and plate shape, and a thickness of 7.5-8.0 mm is selected as an aluminum alloy blank and the following processing is performed:

S1. Cold rolling the selected aluminum alloy billet to the thickness before embossing, and reserving a processing rate of 30-35%;

S2, intermediate annealing, subjecting the aluminum alloy billet treated in step S1 to H24 annealing, the temperature of the aluminum alloy billet is 410-420°C, and the holding time is 4h;

S3, cold rolling and embossing, the aluminum alloy billet treated in step S2 is cold rolled and embossed on a four-roll cold rolling mill at a material temperature of 60-80°C to a finished patterned plate coil with a thickness of 1.143-2.0 mm. During the cold rolling and embossing process, the unwinding unit tension of the aluminum alloy coil is 11-12 N/mm2, the coiling unit tension is 12-15 N/mm2, and the cold rolling and embossing speed is 60±20 m/min; the front slip value of the rolling mill is controlled to be between 5.0±1.0%, and the coiling unit tension of the aluminum alloy coil is dynamically adjusted according to the size of the front slip value;

S4, cleaning, the aluminum alloy coil treated in step S3 is cleaned at a speed of 60-180 m/min. During the cleaning process, the aluminum alloy coil is firstly brushed at room temperature in the form of oil spraying, and then the cleaning oil is sucked dry by a vacuum suction roller, and then washed with deionized water at 70-80° C., and finally purged and dried;

S5, finished product annealing, the aluminum alloy coil treated in step S4 is subjected to H24 state finished product annealing. During the finished product annealing process, the aluminum alloy coil treated in step S4 is first placed in an annealing furnace at 180° C. for 4 hours, and then the temperature in the annealing furnace is increased to 350° C., and after the metal temperature of the aluminum alloy coil reaches 330° C., it is continued to be kept warm for 4 hours;

S6. After completing step S5, a 3004 aluminum alloy patterned plate is obtained.

Furthermore, in said S3, during the cold rolling embossing process, when the current slip value is less than 4.0%, the coiling tension is appropriately increased to increase the front slip value to 5.0%; when the current slip value is greater than 6.0%, the coiling tension is appropriately reduced to reduce the front slip value to 5.0%.

Furthermore, in S3, the temperature of the rolling oil during the cold rolling and embossing process is 45-55°C.

Furthermore, in the step S4, during the oil spray cleaning process, D40 solvent oil is used as the cleaning oil; the aluminum powder level on the surface of the aluminum alloy coil after the cleaning treatment in the step S4 is ≤ level 2; the testing method for the aluminum powder level on the surface of the aluminum alloy coil is that after the aluminum alloy coil is cleaned, use white paper to gently wipe the area 10 cm away from the cold-rolled edge of the aluminum alloy coil for 3 seconds. If the surface of the white paper is clean, the aluminum powder level on the surface of the aluminum alloy coil is level 1; if the surface of the white paper is slightly black, the aluminum powder level on the surface of the aluminum alloy coil is level 2.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention performs an intermediate annealing treatment of the aluminum alloy coil at 410-420°C in the H24 state before the cold rolling and embossing process, which can effectively avoid the coarse grains of the cast 3004 due to recrystallization caused by complete annealing, and reduce the high strength of the early high work hardening, improve the plasticity during embossing, help avoid insufficient rib height, reduce the occurrence of pattern deformation defects, and facilitate the smooth progress of subsequent cold rolling and embossing;

2. After the intermediate annealing of the present invention, the temperature during cold rolling and embossing is 60-80°C. At this temperature, on the one hand, the temperature of the machine is not too high to produce obvious sticking defects; on the other hand, the temperature is relatively high, and the plasticity of the material is greatly improved compared with room temperature, which is conducive to the smooth formation of the pattern during cold rolling and embossing, and can effectively reduce the rolling load during cold rolling and embossing;

3. In the process of cold rolling and embossing, the present invention controls the unwinding and coiling unit tension of the aluminum alloy coil, and controls the speed and forward slip value of the cold rolling and embossing, thereby ensuring that the metal in the deformation zone flows on the neutral plane during cold rolling and embossing, and effectively preventing the pattern distortion and deviation problems caused by the metal in the deformation zone no longer flowing on the neutral plane;

4. In the process of cleaning the aluminum alloy coil, the present invention adopts the process of oil spraying and normal temperature brushing - vacuum washing roller absorbing and drying - 70-80℃ deionized water washing - blowing and drying, which can effectively remove aluminum powder impurities on the surface of the aluminum alloy coil to improve the surface quality of the aluminum alloy coil. After the aluminum alloy coil is sprayed and brushed, the residual cleaning oil on the surface is sucked dry by a vacuum suction roller (at room temperature). In the process of oil absorption, a large amount of aluminum powder is also sucked away at the same time, and the plate surface obtained by further purifying the plate surface has an extremely thin layer of clean protective oil film, which is used to absorb the residual cold rolling oil that is not blown dry by high-pressure air during cold rolling embossing; because the pattern has a certain height, it cannot be completely removed in its shadow, but at this time the residual oil stains are less, and the surface can achieve the effect of cleaning after subsequent water washing and blowing; thereby reducing or avoiding the yellow spots caused by annealing;

5. In the process of finished product annealing, the aluminum alloy coil is first kept at 180°C for 4 hours to remove the cleaning oil remaining on the surface of the aluminum alloy coil, and then the metal temperature of the aluminum alloy coil is controlled at 330°C to improve the material properties of the aluminum alloy, so that the aluminum alloy coil after the finished product annealing has a tensile strength of 220-235MPa, a yield strength of 170-185MPa, good 90°-1t bending, and a smooth and delicate surface after bending. In addition, when annealing at this temperature, the material (casting and rolling) has not yet been recrystallized, so there is no bending orange peel phenomenon caused by coarse grains;

In summary, the 3004 aluminum alloy checkered plate prepared by the method provided by the present invention has good mechanical strength, excellent surface quality and bending effect, and at the same time achieves a significant reduction in cost compared with the production of 3004 checkered plate by hot rolling.

DETAILED DESCRIPTION

The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

A cast-rolled 3004 pattern plate, the composition of the cast-rolled 3004 pattern plate includes the following components in weight percentage: Si=0.15%-0.25%, Fe=0.45%-0.55%, C=0.14%-0.2%, Mn=1.02%-1.15%, Mg=0.95%-1.1%, Cr≤0.05%, Zn≤0.15%, Ti=0.015%-0.025%, other inevitable single elements≤0.05%, total≤0.15%, and the balance is Al.

A method for preparing a cast-rolled 3004 patterned plate, wherein a cast-rolled aluminum alloy coil having a first-grade grain size, good surface quality and plate shape, and a thickness of 7.5-8.0 mm is selected as an aluminum alloy blank and the following processing is performed:

S1. Cold rolling the selected aluminum alloy billet to the thickness before embossing, and reserving a processing rate of 30-35%;

S2, intermediate annealing, subjecting the aluminum alloy billet treated in step S1 to H24 annealing, the temperature of the aluminum alloy billet is 410-420°C, and the holding time is 4h;

S3, cold rolling and embossing, cold rolling and embossing the aluminum alloy billet treated in step S2 to a finished patterned plate coil with a thickness of 1.143-2.0 mm, during the cold rolling and embossing process, the unwinding unit tension of the aluminum alloy coil is 11-12 N/mm ² , the coiling unit tension is 12-15 N/mm ² , and the cold rolling and embossing speed is 60±20 m/min;

S4, cleaning, the aluminum alloy coil treated in step S3 is cleaned, during the cleaning process, firstly, oil spraying is used to brush at room temperature, then a vacuum suction roller is used to remove the cleaning oil, then deionized water at 70-80° C. is used for water washing, and finally, purging and drying are performed;

S5, finished product annealing, the aluminum alloy coil treated in step S4 is subjected to H24 state finished product annealing. During the finished product annealing process, the aluminum alloy coil treated in step S4 is first placed in an annealing furnace at 180° C. for 4 hours, and then the temperature in the annealing furnace is increased to 350° C., and after the metal temperature of the aluminum alloy coil reaches 330° C., it is continued to be kept warm for 4 hours;

S6. After completing step S5, a 3004 aluminum alloy patterned plate is obtained.

In the present invention, after completing step S2, the aluminum alloy coil is withdrawn from the annealing furnace, and step S3 is performed after the metal temperature of the aluminum alloy coil drops to 60-80°C; since the yield strength of the aluminum alloy coil after intermediate annealing drops to between 165-180MPa, matrix recrystallization has not started at this time, and only part of the work hardening is eliminated. Therefore, the aluminum alloy coil is put on the machine for cold rolling and embossing after the metal temperature drops to between 60-80°C, thereby effectively reducing the rolling load during cold rolling and embossing.

In the present invention, in S3, during the cold rolling and embossing process, the forward slip value is controlled between 5.0±1.0%, and the coiling unit tension of the aluminum alloy coil is dynamically adjusted according to the size of the forward slip value; when the forward slip value is less than 4.0%, the coiling tension is appropriately increased to increase the forward slip value to 5.0%; when the forward slip value is greater than 6.0%, the coiling tension is appropriately reduced to reduce the forward slip value to 5.0%; during cold rolling and embossing, the metal in the deformation zone is ensured to flow evenly on the neutral plane to prevent the uniform deformation of the neutral plane from being destroyed, thereby causing the pattern to be distorted and offset.

In the present invention, in S3, the temperature of the rolling oil during the cold rolling and embossing process is 45-55°C. By controlling the temperature of the rolling oil, it is beneficial to lubricate the surface of the aluminum alloy coil.

In the present invention, in the step S4, during the oil spray cleaning process, D40 solvent oil is used as the cleaning oil; the aluminum powder level on the surface of the aluminum alloy coil after the cleaning treatment in the step S4 is ≤ level 2; the cleaning oil of the present invention uses D40 solvent oil, on the one hand, the oil has extremely strong dissolving power, has good wettability to oil stains and aluminum ash, can quickly dissolve the rolling oil and aluminum ash remaining on the surface of the patterned plate, and is convenient for the subsequent vacuum suction roller to adsorb; on the other hand, D40 solvent oil is an environmentally friendly product, evaporates very quickly, and can be volatilized before entering the water cleaning line, thereby reducing the pollution source entering the water tank and facilitating the recycling of water cleaning.

Example 1

A method for preparing a cast-rolled 3004 patterned plate, wherein a cast-rolled aluminum alloy coil having a first-grade grain size, good surface quality and plate shape, and a thickness of 8.0 mm is selected as an aluminum alloy blank and the following processing is performed:

S1. Cold rolling the selected aluminum alloy billet to the thickness before embossing, which is 2.15 mm, and reserving a processing rate of 34.2%;

S2, intermediate annealing, subjecting the aluminum alloy billet processed in step S1 to H24 annealing, the temperature of the aluminum alloy billet is 410° C., and the holding time is 4 hours;

S3, cold rolling and embossing, reducing the metal temperature of the aluminum alloy billet treated in step S2 to 60°C, and then cold rolling and embossing to a finished patterned plate coil with a thickness of 1.414 mm. During the cold rolling and embossing process, the unwinding unit tension of the aluminum alloy coil is 11 N/ ^mm2 , the coiling unit tension is 12 N/ ^mm2 , the cold rolling and embossing speed is 40 m/min, and the rolling oil temperature is 45-55°C;

S4, cleaning, the aluminum alloy coil treated in step S3 is cleaned. During the cleaning process, D40 solvent oil is first used as cleaning oil to perform brushing at room temperature in the form of oil spraying, and then the cleaning oil is sucked dry by a vacuum suction roller, followed by washing with 80° C. deionized water, and finally purging and drying;

S5, finished product annealing, the aluminum alloy coil treated in step S4 is subjected to H24 state finished product annealing. During the finished product annealing process, the aluminum alloy coil treated in step S4 is first placed in an annealing furnace at 180° C. for 4 hours, and then the temperature in the annealing furnace is increased to 350° C., and after the metal temperature of the aluminum alloy coil reaches 330° C., it is continued to be kept warm for 4 hours;

S6. After completing step S5, a 3004 aluminum alloy patterned plate is obtained.

Example 2

A method for preparing a cast-rolled 3004 patterned plate, wherein a cast-rolled aluminum alloy coil having a first-grade grain size, good surface quality and plate shape, and a thickness of 8.0 mm is selected as an aluminum alloy blank and the following processing is performed:

S1. Cold rolling the selected aluminum alloy billet to the thickness before embossing, which is 2.86 mm, and reserving a processing rate of 30%;

S2, intermediate annealing, subjecting the aluminum alloy billet treated in step S1 to H24 annealing, the temperature of the aluminum alloy billet is 420° C., and the holding time is 4 hours;

S3, cold rolling and embossing, reducing the metal temperature of the aluminum alloy billet treated in step S2 to 80°C, and then cold rolling and embossing to a finished patterned plate coil with a thickness of 2.0 mm. During the cold rolling and embossing process, the unwinding unit tension of the aluminum alloy coil is 12 N/ ^mm2 , the coiling unit tension is 14 N/ ^mm2 , the cold rolling and embossing speed is 80 m/min, and the rolling oil temperature is 45-55°C;

S4, cleaning, the aluminum alloy coil treated in step S3 is cleaned. During the cleaning process, D40 solvent oil is first used as cleaning oil to perform brushing at room temperature in the form of oil spraying, and then the cleaning oil is sucked dry by a vacuum suction roller, followed by washing with 80° C. deionized water, and finally purging and drying;

S5, finished product annealing, the aluminum alloy coil treated in step S4 is subjected to H24 state finished product annealing. During the finished product annealing process, the aluminum alloy coil treated in step S4 is first placed in an annealing furnace at 180° C. for 4 hours, and then the temperature in the annealing furnace is increased to 350° C., and after the metal temperature of the aluminum alloy coil reaches 330° C., it is continued to be kept warm for 4 hours;

S6. After completing step S5, a 3004 aluminum alloy patterned plate is obtained.

Example 3

A method for preparing a cast-rolled 3004 patterned plate, wherein a cast-rolled aluminum alloy coil having a first-grade grain size, good surface quality and plate shape, and a thickness of 8.0 mm is selected as an aluminum alloy blank and the following processing is performed:

S1. Cold rolling the selected aluminum alloy billet to the thickness before embossing, which is 2.42 mm, and reserving a processing rate of 34%;

S2, intermediate annealing, subjecting the aluminum alloy billet processed in step S1 to H24 state annealing, the temperature of the aluminum alloy billet is 415° C., and the holding time is 4 hours;

S3, cold rolling and embossing, reducing the metal temperature of the aluminum alloy billet treated in step S2 to 70°C, and then cold rolling and embossing to a finished patterned plate coil with a thickness of 1.6 mm. During the cold rolling and embossing process, the unwinding unit tension of the aluminum alloy coil is 11.5 N/ ^mm2 , the coiling unit tension is 14 N/ ^mm2 , the cold rolling and embossing speed is 40 m/min, and the rolling oil temperature is 45-55°C;

S4, cleaning, the aluminum alloy coil treated in step S3 is cleaned. During the cleaning process, D40 solvent oil is first used as cleaning oil to perform brushing at room temperature in the form of oil spraying, and then the cleaning oil is sucked dry by a vacuum suction roller, followed by washing with deionized water at 70° C., and finally purging and drying;

S5, finished product annealing, the aluminum alloy coil treated in step S4 is subjected to H24 state finished product annealing. During the finished product annealing process, the aluminum alloy coil treated in step S4 is first placed in an annealing furnace at 180° C. for 4 hours, and then the temperature in the annealing furnace is increased to 350° C., and after the metal temperature of the aluminum alloy coil reaches 330° C., it is continued to be kept warm for 4 hours;

S6. After completing step S5, a 3004 aluminum alloy patterned plate is obtained.

Example 4

A method for preparing a cast-rolled 3004 patterned plate, wherein a cast-rolled aluminum alloy coil having a first-grade grain size, good surface quality and plate shape, and a thickness of 8.0 mm is selected as an aluminum alloy blank and the following processing is performed:

S1. Cold rolling the selected aluminum alloy billet to the thickness before embossing, which is 2.68 mm, and reserving a processing rate of 33%;

S2, intermediate annealing, subjecting the aluminum alloy billet processed in step S1 to H24 state annealing, the temperature of the aluminum alloy billet is 415° C., and the holding time is 4 hours;

S3, cold rolling and embossing, reducing the metal temperature of the aluminum alloy billet treated in step S2 to 75°C, and then cold rolling and embossing to a finished patterned plate coil with a thickness of 1.8 mm. During the cold rolling and embossing process, the unwinding unit tension of the aluminum alloy coil is 12N/ ^mm2 , the coiling unit tension is 15N/ ^mm2 , the cold rolling and embossing speed is 80m/min, and the rolling oil temperature is 45-55°C;

S4, cleaning, the aluminum alloy coil treated in step S3 is cleaned. During the cleaning process, D40 solvent oil is first used as cleaning oil to perform brushing at room temperature in the form of oil spraying, and then the cleaning oil is sucked dry by a vacuum suction roller, followed by washing with 80° C. deionized water, and finally purging and drying;

S5, finished product annealing, the aluminum alloy coil treated in step S4 is subjected to H24 state finished product annealing. During the finished product annealing process, the aluminum alloy coil treated in step S4 is first placed in an annealing furnace at 180° C. for 4 hours, and then the temperature in the annealing furnace is increased to 350° C., and after the metal temperature of the aluminum alloy coil reaches 330° C., it is continued to be kept warm for 4 hours;

S6. After completing step S5, a 3004 aluminum alloy patterned plate is obtained.

Comparative Example 1

The production method of Comparative Example 1 is roughly the same as that of Example 1, except that after completing step S1, a high-temperature homogenization heat treatment annealing is performed, the metal billet temperature is 530-540°C, and the insulation time is 8h; compared with Example 1, the advantage of this scheme is that it ensures the smooth progress of the subsequent cold rolling embossing, while also ensuring the bending quality, but the main disadvantage is that the cost of the homogenization treatment is relatively high.

Comparative Example 2

The production method of Comparative Example 2 is substantially the same as that of Example 1, except that in step S3, the aluminum alloy coil is cooled to room temperature before cold rolling and embossing. Compared with Example 1, the main difference is that the plasticity is slightly worse during rolling mill embossing and the rolling mill load is larger.

Comparative Example 3

The production method of Comparative Example 3 is substantially the same as that of Example 1, except that step S2 is not performed before embossing, i.e., intermediate annealing is not performed, and the cold-rolled aluminum alloy coil is directly subjected to cold-rolling embossing treatment. At this time, the cold-rolling embossing process cannot be carried out smoothly due to the poor plasticity of the material.

Comparative Example 4

The production method of Comparative Example 4 is roughly the same as that of Example 1, except that the uncoiling unit tension, coiling unit tension, and rolling mill front slip value during cold rolling embossing are not within the required range of the specific implementation method, which results in the embossing quality being unable to be well guaranteed and the pattern qualification rate being low.

Comparative Example 5

The production method of Comparative Example 5 is roughly the same as that of Example 1, with the main difference being that the rolling oil temperature during cold working embossing is 40°C, which results in poorer lubrication quality of the rolling mill and higher load on the rolling mill during embossing compared to Example 1, and also poorer mirror effect of the patterned plate after embossing.

Comparative Example 6

The production method of Comparative Example 6 is roughly the same as that of Example 1, with the main difference being that only ordinary hot-rolled patterned plate water cleaning operation was performed during cleaning. Compared with Example 1, more aluminum ash remained after cleaning, and the plate surface quality was poor.

Comparative Example 7

The production method of Comparative Example 7 is roughly the same as that of Example 1, with the main difference being that during the annealing of the finished product, the annealing temperature is higher than 350°C, and the metal temperature of the aluminum alloy coil is higher, so that the material undergoes complete recrystallization. Ultimately, although no cracking is achieved during bending compared to Example 1, the coarse grains result in obvious orange peel after bending, which is unacceptable to customers.

Through the examples 1-4 and comparative examples 1-7, it can be seen that the technical parameters required by this patent well guarantee the economy and practicality of producing 3004 patterned plates by the casting and rolling method.

Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims (4)

1. A preparation method of a cast-rolled 3004 checkered plate is characterized in that a cast-rolled aluminum alloy coiled material with primary grain size, good surface quality and plate shape and thickness of 7.5-8.0mm is selected as an aluminum alloy blank, and the following treatment process is carried out:

s1, cold rolling a selected aluminum alloy blank to the thickness before embossing, and reserving a machining rate of 30-35%;

S2, intermediate annealing, namely carrying out H24-state annealing on the aluminum alloy blank processed in the step S1, wherein the temperature of the aluminum alloy blank is 410-420 ℃, and the heat preservation time is 4 hours;

s3, cold rolling and embossing, namely cold rolling and embossing the aluminum alloy blank processed in the step S2 to a finished pattern plate coiled material with the thickness of 1.143-2.0mm on a four-roller cold rolling mill at the material temperature of 60-80 ℃, wherein in the cold rolling and embossing process, the uncoiling unit tension of the aluminum alloy coiled material is 11-12N/mm ², the coiling unit tension is 12-15N/mm ², and the cold rolling and embossing speed is 60+/-20 m/min; controlling the forward slip value of the rolling mill to be 5.0+/-1.0%, and dynamically adjusting the coiling unit tension of the aluminum alloy coiled material according to the magnitude of the forward slip value;

S4, cleaning, namely cleaning the aluminum alloy coiled material treated in the step S3 at the speed of 60-180m/min, brushing at normal temperature by adopting an oil spraying mode in the cleaning process, sucking the cleaning oil by using a vacuum suction roller, washing by using deionized water at the temperature of 70-80 ℃, and finally carrying out purging and drying treatment;

s5, annealing the finished product, namely carrying out H24-state finished product annealing on the aluminum alloy coiled material treated in the step S4, in the finished product annealing process, firstly placing the aluminum alloy coiled material treated in the step S4 into an annealing furnace, preserving heat for 4 hours at 180 ℃, then raising the temperature in the annealing furnace to 350 ℃, and continuing preserving heat for 4 hours after the metal temperature of the aluminum alloy coiled material reaches 330 ℃;

s6, after the step S5 is completed, the 3004 aluminum alloy checkered plate percent is obtained.

2. The method for manufacturing a cast-rolled 3004 checkered plate according to claim 1, wherein: in the step S3, when the current slip value is smaller than 4.0% in the cold rolling embossing process, the coiling tension is properly increased so as to increase the current slip value to 5.0%; when the front slip value is greater than 6.0%, the winding tension is appropriately reduced so that the front slip value is reduced to 5.0%.

3. The method for manufacturing a cast-rolled 3004 checkered plate according to claim 1, wherein: in the step S3, the temperature of the rolling oil in the cold rolling embossing process is 45-55 ℃.

4. The method for manufacturing a cast-rolled 3004 checkered plate according to claim 1, wherein: in the step S4, D40 solvent oil is adopted as cleaning oil in the oil spraying cleaning process; and (3) the aluminum powder grade on the surface of the aluminum alloy coiled material after the cleaning treatment in the step (S4) is less than or equal to 2 grade.