A rolling production process for ultra-thin aluminum alloy strip

Abstract

The invention relates to a rolling production process for an ultra-thin aluminum alloy strip. The rolling production process sequentially comprises material selection, heating, hot rough rolling, hot finishing rolling, uncoiling inspection and post-processing. The process is designed from aspects such as heating system, rolling pass, lubrication and cooling medium management, and rolling processing rate distribution. By controlling key points such as chemical composition, intermediate billet thickness, maximum reduction, speed increase rate, and spray mode, the thickness specification limit of the current hot continuous rolling production product in the industry is broken through. According to the rolling production process, the size and plate shape of the 1.5 mm hot-rolled ultra-thin specification strip can be guaranteed to be normal. The process provides a new idea and direction for further reducing the production cost of the overall products in the aluminum processing industry.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum profile preparation and processing, and relates to a rolling production process for ultra-thin aluminum alloy strips, and in particular to a rolling production process for ultra-thin aluminum alloy strips suitable for 1xxx, 3xxx, 6xxx, and 8xxx series and produced by a hot rolling mill. Background Art

[0002] Lightweight and high speed have become important symbols of modern transportation. The use of aluminum alloy materials is an effective measure to reduce the weight of the vehicle body. In order to adapt to development, countries around the world are vigorously developing and manufacturing structural parts for aluminum alloy vehicle bodies. The development of high-quality ultra-thin and ultra-wide aluminum alloy component preparation technology plays a vital role in promoting the development of the transportation industry.

[0003] At present, the hot rolling mill rolling technology in the industry can achieve a minimum thickness specification of 2.0mm for high-quality ultra-thin aluminum alloy strips; the industry currently produces 1.5mm thickness products mainly through hot rolling to 2.5-3.0mm thickness, and then one cold rolling pass; the existing rolling technology has a long production cycle and high processing costs. The hot rolling mill rolling technology for producing ultra-thin products can greatly shorten the production cycle and reduce processing production costs. Summary of the invention

[0004] In view of this, the present invention provides a rolling production process for ultra-thin aluminum alloy strips in order to solve the problem that the hot rolling mill rolling technology in the prior art can achieve ultra-thin aluminum alloy strips with a minimum thickness of 2.0 mm, but cannot directly roll and produce ultra-thin aluminum alloy strips with a thickness of 1.5 mm, which affects the production cycle and increases production costs.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A rolling production process for ultra-thin aluminum alloy strips comprises the following steps:

[0007] A. Material selection: Considering the characteristics of various aluminum alloy materials and equipment capabilities, select the aluminum alloy series for preparing ultra-thin aluminum alloy strips and mix the components according to weight percentage;

[0008] B. Heating: Add the prepared aluminum alloy raw materials into the melting furnace and mix them evenly, then melt them into liquid aluminum alloy. After standing, refining, slag removal, online degassing and filtering, the liquid aluminum alloy is melted into aluminum alloy ingots. After the aluminum alloy ingots are sawed and milled, they are placed in a heating furnace for heating. The heating furnace temperature is 480-520℃, and the insulation time is 2-3h.

[0009] C. Hot rough rolling: The aluminum alloy ingot after heating and heat preservation is taken out of the furnace for hot rolling, the rolling pass is 13, and when the thickness of the intermediate billet is 110-120mm, the head and tail crocodile mouths are cut off, and then the rolling is repeated for 4 times until the thickness is 24-25mm, the single pass reduction is 15-40mm, the rolling speed is 1.9-3.2m / s, and the temperature of the intermediate billet is 400-460℃;

[0010] D. Hot finishing rolling: The slab rolled to a thickness of 24-25 mm by the hot roughing mill is thinned to a thickness of 1.5±0.03 mm by four hot finishing rolling stands one by one and then coiled. The final rolling temperature is 300-320°C. The processing rate distribution method of F1-F4 stands is (49±1)%-(51±1)%-(51±1)%-(50±1)%. The tension between F1-F4 stands and the outlet of F4 stand is set to 9-11-14-19N / mm 2 ;

[0011] E. Uncoiling inspection: Uncoil the coiled material for inspection, and perform product size inspection and alkali washing according to product size and surface quality requirements. The thickness tolerance of aluminum alloy coil is ±0.03mm, the width tolerance is 0-5mm, the convexity is 0-0.6%, and the wedge shape is ≤0.35%;

[0012] F. Post-processing: The coils that have been judged to be qualified are slowly cooled to room temperature and then transferred to the cold rolling process for subsequent processing.

[0013] Furthermore, in step A, the aluminum alloy series used for the ultra-thin aluminum alloy strip is 1xxx, 3xxx, 6xxx or 8xxx series.

[0014] Furthermore, the aluminum alloy ingot after melting and casting in step B is homogenized in a homogenizing furnace at a temperature of 550-600° C. for a holding time of 8-12 hours.

[0015] Furthermore, in step C, the first 13 hot rough rolling passes adopt a small reduction in the first and last passes and a large reduction in the middle passes.

[0016] Furthermore, in step C, in order to take into account the lubrication and cooling performance of the lubricating cooling medium during the hot rough rolling process, the emulsion concentration in the hot rough rolling is controlled to be 3.5-3.6%, the grease content is controlled to be 21-22%, the non-bound acid content is controlled to be 4.1-4.2%, the emulsion system temperature is controlled to be 56°C, and the emulsion system pressure is controlled to be 4.5 bar.

[0017] Furthermore, in step D, the cooling mode of the spray beams of the F1-F4 stands in the hot finishing rolling adopts an inlet cooling spray beam + an outlet cooling spray beam.

[0018] Furthermore, in step D, in order to take into account the lubrication and cooling performance of the lubricating cooling medium during the hot finishing rolling process, the finishing rolling emulsion concentration is controlled to be 7.0-7.1%, the grease content is controlled to be 30.5-31.5%, the non-bound acid content is controlled to be 10.5-11.5%, the emulsion system temperature is controlled to be 56°C, and the emulsion system pressure is controlled to be 4.5 bar.

[0019] The beneficial effects of the present invention are:

[0020] 1. The rolling production process of the ultra-thin aluminum alloy strip disclosed in the present invention is designed from the aspects of heating system, rolling pass, lubrication and cooling medium management, rolling processing rate distribution, etc., and breaks through the current industry's hot rolling production product thickness specification limit by controlling key points such as chemical composition, intermediate billet thickness, maximum reduction, speed increase rate, spray mode, etc. According to this rolling production process, the size and plate shape of 1.5mm hot-rolled ultra-thin specification strip can be guaranteed to be normal; it provides new ideas and directions for further reducing the production cost of the overall products of the aluminum processing industry.

[0021] 2. The rolling production process of the ultra-thin aluminum alloy strip disclosed in the present invention produces products with a thickness specification in the range of 1.5-2.0mm through the thinning hot rolling process, thereby reducing the number of processing passes and processing time in the cold rolling process, improving the overall processing efficiency, shortening the overall production cycle of order products, reducing the overall production and processing costs, and enhancing the market competitiveness of products; through the emulsion temperature monitoring, emulsion system pressure setting, spray beam spray mode use control and reasonable rack usage and processing rate distribution method during the hot finishing rolling production process, the plate shape stability of the strip is effectively guaranteed.

[0022] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0024] Figure 1 Schematic diagram of the structure of the aluminum alloy coil after rolling according to the rolling production process of the ultra-thin aluminum alloy strip in Example 1 of the present invention Figure 1 ;

[0025] Figure 2 Schematic diagram of the structure of the aluminum alloy coil after rolling according to the rolling production process of the ultra-thin aluminum alloy strip in Example 1 of the present invention Figure 2 . DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present invention by 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 the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept 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.

[0027] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0028] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0029] Example 1

[0030] A rolling production process for ultra-thin aluminum alloy strips comprises the following steps:

[0031] A. Material selection: According to the characteristics of aluminum alloy materials and order conditions, 3004 aluminum-manganese alloy is selected for the preparation of ultra-thin aluminum alloy strips, and the components are proportioned according to weight percentage.

[0032] B. Heating: Add the prepared aluminum alloy raw materials into the melting furnace, mix them evenly, and then melt them into liquid aluminum alloy. After standing, refining, slag removal, online degassing, and filtering processes, the liquid aluminum alloy is melted into aluminum alloy ingots. The aluminum alloy ingots after melting and casting are homogenized in a homogenizing furnace at a temperature of 600°C and a holding time of 10 hours. After the aluminum alloy ingots after homogenization are sawed and milled, they are placed in a heating furnace for heating at a temperature of 480°C and a holding time of 2 hours.

[0033] C. Hot rough rolling: The aluminum alloy ingot after heating and insulation is taken out of the furnace for hot rolling, and the rolling pass is 13. When the thickness of the intermediate billet is 112mm, the head and tail crocodile mouths are cut off, and then 4 passes of rolling are repeated until the thickness is 24mm. The reduction of a single pass is 15-40mm, the rolling speed is 2.1-3.2m / s, and the temperature of the intermediate billet is 400-460℃; in order to take into account the lubrication and cooling performance of the lubricating cooling medium during the hot rough rolling, the emulsion concentration in the hot rough rolling is controlled to be 3.5-3.6%, the grease content is controlled to be 21-22%, the non-combined acid content is controlled to be 4.1-4.2%, the emulsion system temperature is controlled to be 56℃, and the emulsion system pressure is controlled to be 4.5bar.

[0034] D. Hot finishing rolling: The slab rolled to a thickness of 24 mm by the hot roughing mill is thinned to a thickness of 1.5 ± 0.03 mm by four hot finishing rolling stands one by one and then coiled. The final rolling temperature is 300-320°C, and the processing rate distribution method of F1-F4 stands is 49%-51%-51%-50%. The tension between F1-F4 stands and the outlet of F4 stand is set to 9-11-14-19N / mm 2 In order to take into account the lubrication and cooling performance of the lubricating cooling medium during the hot finishing rolling process, the concentration of the finishing rolling emulsion is controlled at 7.0-7.1%, the grease content is controlled at 30.5-31.5%, the non-combined acid content is controlled at 10.5-11.5%, the emulsion system temperature is controlled at 56°C, and the emulsion system pressure is controlled at 4.5 bar.

[0035] E. Uncoil inspection: Uncoil the coiled material for inspection. The actual thickness is 1.512mm, the actual width is 1138mm, the actual convexity is 0.34%, and the actual wedge shape is 0.05%.

[0036] F. Post-processing: The coils that have passed the product quality assessment are slowly cooled to room temperature, and then transferred to the cold rolling process for subsequent processing. The structural diagram after rolling is shown in Figure 1 and Figure 2 .

[0037] Example 2

[0038] A rolling production process for ultra-thin aluminum alloy strips comprises the following steps:

[0039] A. Material selection: According to the characteristics of aluminum alloy materials and order conditions, 6061 aluminum-magnesium alloy is selected for the preparation of ultra-thin aluminum alloy strips, and the components are proportioned according to weight percentage.

[0040] B. Heating: Add the prepared aluminum alloy raw materials into the melting furnace, mix them evenly and then melt them into liquid aluminum alloy. After standing, refining, slag removal, online degassing and filtering processes, the liquid aluminum alloy is melted and cast into aluminum alloy ingots. The aluminum alloy ingots after melting and casting are not subjected to homogenization treatment. After the aluminum alloy ingots are sawed and milled, they are placed in a heating furnace for heating. The heating furnace temperature is 500°C and the insulation time is 3 hours.

[0041] C. Hot rough rolling: The aluminum alloy ingot after heating and heat preservation is taken out of the furnace for hot rolling, and the rolling pass is 13. When the thickness of the intermediate billet is 119 mm, the head and tail crocodile mouths are cut off, and then 4 passes of rolling are repeated until the thickness is 25 mm. The single pass reduction is 15-40 mm, the rolling speed is 1.9-3.2 m / s, and the intermediate billet temperature is 400-460°C; in order to take into account the lubrication and cooling performance of the lubricating cooling medium during the hot rough rolling, the emulsion concentration is controlled to be 3.5-3.6%, the grease content is controlled to be 21-22%, the non-combined acid content is controlled to be 4.1-4.2%, the emulsion system temperature is controlled to be 56°C, and the emulsion system pressure is controlled to be 4.5 bar.

[0042] D. Hot finishing rolling: The slab rolled to a thickness of 25 mm by the hot roughing mill is thinned to a thickness of 1.5 ± 0.03 mm by four hot finishing rolling stands one by one and then coiled. The final rolling temperature is 300-320°C, and the processing rate distribution method of F1-F4 stands is 50%-52%-52%-49%. The tension between F1-F4 stands and the outlet of F4 stand is set to 9-11-14-19N / mm 2 In order to take into account the lubrication and cooling performance of the lubricating cooling medium during the hot finishing rolling process, the concentration of the finishing rolling emulsion is controlled at 7.0-7.1%, the grease content is controlled at 30.5-31.5%, the non-combined acid content is controlled at 10.5-11.5%, the emulsion system temperature is controlled at 56°C, and the emulsion system pressure is controlled at 4.5 bar.

[0043] E. Uncoil inspection: Uncoil the coiled material for inspection. The actual thickness is 1.503mm, the actual width is 1044mm, the actual convexity is 0.21%, and the actual wedge shape is 0.29%.

[0044] F. Post-processing: The coils that have been judged to be qualified are slowly cooled to room temperature and then transferred to the cold rolling process for subsequent processing.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A rolling production process for ultra-thin aluminum alloy strip, characterized in that: The steps include: A. Material selection: Considering the characteristics of various aluminum alloy materials and equipment capabilities, select the aluminum alloy series for preparing ultra-thin aluminum alloy strips and mix the components according to weight percentage; B. Heating: Add the prepared aluminum alloy raw materials into the melting furnace and mix them evenly, then melt them into liquid aluminum alloy. After standing, refining, slag removal, online degassing and filtering, the liquid aluminum alloy is melted into aluminum alloy ingots. After the aluminum alloy ingots are sawed and milled, they are placed in a heating furnace for heating. The heating furnace temperature is 480~520℃, and the insulation time is 2~3h. C. Hot rough rolling: The aluminum alloy ingot after heating and heat preservation is taken out of the furnace for hot rolling, and the rolling pass is 13. When the thickness of the intermediate billet is 110-120 mm, the head and tail crocodile mouths are cut off, and then the rolling is repeated for 4 times until the thickness is 24-25 mm. The single-pass reduction is 15-40 mm, the rolling speed is 1.9-3.2 m / s, and the intermediate billet temperature is 400-460 ° C; D. Hot finishing rolling: The slab rolled to a thickness of 24-25 mm by the hot roughing mill is thinned to a thickness of 1.5±0.03 mm by four hot finishing rolling stands one by one and then coiled. The final rolling temperature is 300-320°C. The processing rate distribution method of F1-F4 stands is (49±1)%-(51±1)%-(51±1)%-(50±1)%. The tension between F1-F4 stands and the outlet of F4 stand is set to 9-11-14-19N / mm 2 ; E. Uncoiling inspection: Uncoil the coiled material for inspection, and perform product size inspection and alkali washing according to product size and surface quality requirements. The thickness tolerance of aluminum alloy coil is ±0.03mm, the width tolerance is 0~5mm, the convexity is 0~0.6%, and the wedge shape is ≤0.35%; F. Post-processing: The coils that have passed the product quality assessment are slowly cooled to room temperature, and then transferred to the cold rolling process for subsequent processing; Step B: the aluminum alloy ingot after melting and casting is homogenized in a homogenizing furnace at a temperature of 550-600° C. for a holding time of 8-12 hours; In step C, the first 13 hot rough rolling passes are rolled with a small reduction in the first and last passes and a large reduction in the middle passes; In step C, during hot rough rolling, the emulsion concentration is controlled to be 3.5-3.6%, the grease content is controlled to be 21-22%, the non-bound acid content is controlled to be 4.1-4.2%, the emulsion system temperature is controlled to be 56° C., and the emulsion system pressure is controlled to be 4.5 bar; In step D, the cooling mode of the spray beams of the F1-F4 stands in the hot finishing rolling adopts the inlet cooling spray beam + the outlet cooling spray beam; In step D, the concentration of the finishing emulsion in hot finishing rolling is controlled to be 7.0-7.1%, the grease content is controlled to be 30.5-31.5%, the non-bound acid content is controlled to be 10.5-11.5%, the emulsion system temperature is controlled to be 56° C., and the emulsion system pressure is controlled to be 4.5 bar.

2. The rolling production process of ultra-thin aluminum alloy strip according to claim 1, characterized in that: The aluminum alloy series used for the ultra-thin aluminum alloy strip in step A is 1xxx, 3xxx, 6xxx or 8xxx series.

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