Curtain wall plate base material and processing method

Abstract

The invention relates to a curtain wall plate base material and a machining method, and relates to the technical field of aluminum alloy plate strip foil machining. The machining method comprises the steps of double-roller continuous cast rolling, cold rolling and annealing. Wherein the annealing process adopts a step-by-step annealing mode and comprises a plurality of stages such as preheating, first-time oil removal, first-time heating, second-time oil removal, second-time heating, performance control, cooling and adjustment. According to the method, the specific alloy component proportion (Al-Mn-Fe-Si-Cu series) is combined with the multi-stage oil removal and recrystallization annealing process, rolling oil residues on the surface of the plate are effectively removed, internal stress is eliminated, and the grain structure is refined. The surface of the prepared curtain wall plate base material is clean and free of oil spots, the good mechanical property (the tensile strength is larger than or equal to 145 MPa, and the elongation is larger than or equal to 15%) and the good bending machinability are achieved, and the use requirements of high-quality building curtain walls are met.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy sheet, strip, and foil processing technology, and in particular to a curtain wall panel substrate and processing method. Background Technology

[0002] Aluminum panels for curtain walls, with their excellent mechanical properties, corrosion resistance, and ease of cleaning, and especially their rich colors and design capabilities, add unique visual effects to commercial, public, and cultural buildings. Common aluminum alloys used for curtain walls include the 3003, 1100, 5005, and 6061 series, with aluminum panel thicknesses generally ranging from 1.5mm to 3.5mm.

[0003] Different series of alloys have different performance and surface quality requirements due to their suitability for different building characteristics. High-quality aluminum panels for curtain walls should have sufficient strength, hardness, and toughness. Generally speaking, the tensile strength of aluminum panels for curtain walls should not be less than 145MPa, and the elongation should not be less than 15%; excellent bending properties; surface quality requirements mainly include good surface flatness, smooth surface, no obvious bumps, deformation, or waviness; good color uniformity, no color difference; and excellent surface cleanliness, with the aluminum panel surface clean and free from defects such as oil stains, dirt, scratches, adhesive marks, and dents.

[0004] Adhesion and scratch defects are common in aluminum alloy strips used for curtain wall panels during production, processing and subsequent treatment. These defects not only affect the surface quality of the aluminum alloy strips, but may also reduce their mechanical properties, thereby affecting the final performance and aesthetics of the curtain wall panels and increasing production costs. Summary of the Invention

[0005] To address the aforementioned issues, this application provides a curtain wall panel substrate and a processing method thereof.

[0006] In a first aspect, this application provides a method for processing a curtain wall panel substrate, which adopts the following technical solution: A method for processing a curtain wall panel substrate includes the following steps: S1. Twin-roll continuous casting and rolling: After melting the liquid aluminum alloy, it is cast and rolled into billet coils by a continuous casting and rolling mill. S2. Cold rolling: The billet coil is cold rolled from the initial thickness to the target thickness to obtain an aluminum alloy sheet; S3. Annealing: The aluminum alloy sheet is subjected to step-by-step annealing in an annealing furnace to obtain the curtain wall panel substrate.

[0007] Optionally, the mass fraction of each element in the liquid aluminum alloy is: manganese 1.0%~1.5%, iron 0.3%~0.7%, silicon 0.2%~0.6%, copper 0.05%~0.2%, titanium ≤0.03%, zinc 0.001%~0.1%, with the balance being aluminum and unavoidable impurities.

[0008] Optionally, in step S1, the temperature of the casting and rolling chamber of the casting and rolling mill is 685℃-705℃; the length of the casting and rolling zone is 45-55mm; the casting and rolling speed is 800-1000mm / min; the liquid metal is electrolytic aluminum liquid, and titanium wire is added before entering the casting and rolling mill for online slag and gas removal.

[0009] Optionally, in step S2, the initial thickness of the blank roll is 6.4-7.4 mm, and the target thickness is 1.5-3.5 mm; The specific rolling passes of the cold rolling process are as follows: first, the billet coil is rolled to an intermediate thickness of 3.8-4.3 mm, and then the intermediate thickness plate coil is rolled to the target thickness.

[0010] Optionally, in step S3, the step-by-step annealing specifically includes the following sequentially performed stages: Preheating section: The annealing furnace is heated to 230℃ within 0.5-3 hours; First degreasing stage: Keep warm at 230℃ for 3-6 hours; First heating stage: Adjust the annealing furnace temperature to 230-360℃, and control the heating time to 4-6 hours; Second degreasing stage: Adjust the annealing furnace temperature to 340-370℃ and hold for 4-6 hours; Second heating stage: Adjust the annealing furnace temperature to 360-410℃, and control the heating time to 1-3 hours; Performance control section: Adjust the annealing furnace temperature to 400-420℃ and hold for 11-18 hours; Cooling section: Adjust the annealing furnace temperature to 380-420℃, and process for 0.5-2 hours; Adjustment section: Adjust the annealing furnace temperature to 380-400℃ and hold for 2-6 hours.

[0011] Secondly, this application provides a curtain wall panel substrate.

[0012] A curtain wall panel substrate, wherein the tensile strength of the curtain wall panel substrate is ≥145MPa and the elongation after fracture is ≥15%. In summary, this application includes at least one of the following beneficial technical effects: By replacing the traditional hot rolling process with twin-roll continuous casting and rolling, the production process can be shortened and energy consumption reduced. Combined with subsequent cold rolling and specific step-by-step annealing processes, aluminum alloy substrates that meet the requirements of curtain wall panels can be produced efficiently with low cost and high quality. By optimizing the alloy composition and controlling the Mn (manganese) content within the range of 1.0%-1.5%, the excellent rust and corrosion resistance and basic strength of the substrate are guaranteed. With appropriate amounts of Fe (iron) and Si (silicon), a dispersed second phase is formed during the casting and rolling process, which helps to refine the grains. Trace amounts of Cu (copper) further enhance the strength of the substrate, enabling it to meet the requirements of the curtain wall panel for wind pressure resistance. By limiting the temperature and speed of the pre-casting and rolling box, the compactness of the internal structure of the billet is ensured, and porosity and looseness defects are reduced. The specific cold rolling reduction distribution (rolled from 6.4-7.4mm to the target thickness) accumulates sufficient dislocation density through work hardening, which provides a driving force for recrystallization in the subsequent annealing process and helps to obtain a uniform grain structure. Through a stepped heating and long-term heat preservation process involving a preheating section, a first degreasing section, a first heating section, a second degreasing section, and a second heating section, the rolling oil on the surface of the panel is fully volatilized and burned, solving the common problems of surface oil spots and oil residue in curtain wall panels. This significantly improves surface cleanliness and dyne value, facilitating subsequent coating or anodizing treatments. The long-term heat preservation in the performance control section ensures complete recrystallization of the material, eliminating the internal stress generated by cold rolling and giving the material excellent flexibility and bending performance. The adjustment section precisely controls the grain size of the final product, enabling the curtain wall panel substrate to have both high strength (≥145MPa) and high elongation (≥15%), effectively resolving the contradiction between strength and formability, and resulting in a smooth panel surface without wavy lines. Detailed Implementation

[0013] This application discloses a method for processing a curtain wall panel substrate.

[0014] Example 1: A method for processing a curtain wall panel substrate includes the following steps: S1: Melting and Casting: Electrolytic aluminum liquid is used, and the alloy composition (mass fraction) is prepared as follows: Mn 1.0%, Fe 0.3%, Si 0.2%, Cu 0.05%, Zn 0.05%, Ti 0.01%, with the balance being Al. The melt is refined, allowed to stand, degassed and deslag-removed online, and titanium wire is added. The temperature of the casting box is controlled at 685℃, the length of the casting zone is 45mm, the casting speed is 800mm / min, and the billet is cast into a coil with a thickness of 6.4mm.

[0015] S2: Cold rolling: The 6.4mm billet coil is first rolled to 3.8mm, and then rolled to the target thickness of 1.5mm. S3: Step-by-step annealing: The cold-rolled sheet is placed into the annealing furnace and the following process is performed: Preheating: Increase the temperature to 230℃ in 0.5 hours; First degreasing: Keep at 230℃ for 6 hours; First heating cycle: 230-360℃, taking 4 hours; Second degreasing: Keep at 340℃ for 6 hours; Second heating: 340-360℃, taking 1 hour; Performance control: 400℃ heat preservation for 18 hours; Cooling: Adjusted to 380℃, time taken 0.5 hours; Adjustment: Hold at 380℃ for 6 hours, then remove from the furnace and air cool.

[0016] Example 2: A method for processing a curtain wall panel substrate includes the following steps: S1: Melting and Casting: Alloy composition (mass fraction): Mn 1.25%, Fe 0.5%, Si 0.4%, Cu 0.12%, Zn 0.05%, Ti 0.02%, balance Al. The pre-casting box temperature is controlled at 695℃, the casting zone length is 50mm, the casting speed is 900mm / min, and the billet is cast into a coil with a thickness of 7.0mm.

[0017] S2: Cold rolling: The 7.0mm billet coil is first rolled to 4.0mm, and then rolled to the target thickness of 2.5mm.

[0018] S3: Step-by-step annealing: The cold-rolled sheet is placed into the annealing furnace and the following process is performed: Preheating: 1.5 hours to reach 230℃; First degreasing: Hold at 230℃ for 4.5 hours; First heating cycle: 230-360℃, taking 5 hours; Second degreasing: Keep at 355℃ for 5 hours; Second heating: 355-385℃, taking 2 hours; Performance control: 410℃ for 15 hours; Cooling: Adjusted to 400℃, time taken 1 hour; Adjustment: Hold at 390℃ for 4 hours, then remove from the oven and air cool.

[0019] Example 3: A method for processing a curtain wall panel substrate includes the following steps: S1: Melting and Casting: Alloy composition (mass fraction): Mn 1.5%, Fe 0.7%, Si 0.6%, Cu 0.2%, Zn 0.1%, Ti 0.03%, balance Al. The pre-casting box temperature is controlled at 705℃, the casting zone length is 55mm, the casting speed is 1000mm / min, and the billet is rolled into a coil with a thickness of 7.4mm.

[0020] S2: Cold rolling: The 7.4mm billet coil is first rolled to 4.3mm, and then rolled to the target thickness of 3.5mm.

[0021] S3: Step-by-step annealing: The cold-rolled sheet is placed into the annealing furnace and the following process is performed: Preheating: Increase the temperature to 230℃ in 3 hours; First degreasing: Keep at 230℃ for 3 hours; First heating: 230-360℃, taking 6 hours; Second degreasing: Keep at 370℃ for 4 hours; Second heating: 370-410℃, taking 3 hours; Performance control: 420℃ heat preservation for 11 hours; Cooling: Adjust to 420℃ (this is to maintain or fine-tune), taking 1 hour; Adjustment: Hold at 400℃ for 2 hours, then remove from the oven and air cool.

[0022] Performance test results: The performance of the curtain wall panel substrates obtained in Examples 1 to 3 was tested, and the test results are shown in the table below: ; As shown in the table above, the curtain wall panel substrates prepared using the processing method described in this application have tensile strengths exceeding 145 MPa, elongation exceeding 15%, and excellent surface quality, fully meeting the requirements for high-quality curtain wall panels.

[0023] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for processing a curtain wall panel substrate, characterized in that, Includes the following steps: S1. Twin-roll continuous casting and rolling: After melting the liquid aluminum alloy, it is cast and rolled into billet coils by a continuous casting and rolling mill. S2. Cold rolling: The billet coil is cold rolled from the initial thickness to the target thickness to obtain an aluminum alloy sheet; S3. Annealing: The aluminum alloy sheet is subjected to step-by-step annealing in an annealing furnace to obtain the curtain wall panel substrate.

2. The method for processing a curtain wall panel substrate according to claim 1, characterized in that, The mass fraction of each element in the liquid aluminum alloy is as follows: manganese 1.0%~1.5%, iron 0.3%~0.7%, silicon 0.2%~0.6%, copper 0.05%~0.2%, titanium ≤0.03%, zinc 0.001%~0.1%, with the balance being aluminum and unavoidable impurities.

3. The method for processing a curtain wall panel substrate according to claim 1, characterized in that, In step S1, the temperature of the casting and rolling chamber of the casting and rolling mill is 685℃-705℃; the length of the casting and rolling zone is 45-55mm; the casting and rolling speed is 800-1000mm / min; the liquid metal is electrolytic aluminum liquid, and titanium wire is added before entering the casting and rolling mill for online slag and gas removal.

4. The method for processing a curtain wall panel substrate according to claim 1, characterized in that, In step S2, the initial thickness of the blank roll is 6.4-7.4 mm, and the target thickness is 1.5-3.5 mm; The specific rolling passes of the cold rolling process are as follows: first, the billet coil is rolled to an intermediate thickness of 3.8-4.3 mm, and then the intermediate thickness plate coil is rolled to the target thickness.

5. A method for processing a curtain wall panel substrate according to claim 1, characterized in that, In step S3, the step-by-step annealing specifically includes the following sequentially performed stages: Preheating section: The annealing furnace is heated to 230℃ within 0.5-3 hours; First degreasing stage: Keep at 230℃ for 3-6 hours; First heating stage: Adjust the annealing furnace temperature to 230-360℃, and control the heating time to 4-6 hours; Second degreasing stage: Adjust the annealing furnace temperature to 340-370℃ and hold for 4-6 hours; Second heating stage: Adjust the annealing furnace temperature to 360-410℃, and control the heating time to 1-3 hours; Performance control section: Adjust the annealing furnace temperature to 400-420℃ and hold for 11-18 hours; Cooling section: Adjust the annealing furnace temperature to 380-420℃, and process for 0.5-2 hours; Adjustment section: Adjust the annealing furnace temperature to 380-400℃ and hold for 2-6 hours.

6. A curtain wall panel substrate, characterized in that, It is prepared by the processing method of the curtain wall panel substrate according to any one of claims 1-5.

7. A curtain wall panel substrate according to claim 6, characterized in that, The tensile strength of the curtain wall panel substrate is ≥145MPa, and the elongation after fracture is ≥15%.