Al-si alloy thin strip and preparation process thereof

Abstract

The application discloses an Al-Si series alloy thin strip and a preparation process thereof, and belongs to the field of non-ferrous metal material processing.The chemical composition and mass percentage of the thin strip are as follows: Si is less than or equal to 0.8%, Mg is less than or equal to 0.15%, Mn is greater than 1.5%, Fe is less than or equal to 0.5%, Ag is greater than or equal to 0.1%, and the balance is Al and inevitable impurities.An aluminum alloy ingot meeting the above composition is sequentially subjected to heating, hot rolling, cold rolling, annealing, cold rolling and shearing and edge trimming to obtain the thin strip.The aluminum alloy thin strip provided by the application has good dimensional precision.The outstanding advantages are that the aluminum alloy thin strip has excellent comprehensive performance such as 90-degree bending performance and corrosion resistance, and the downstream customers can obtain good use effect after processing.The key technical problem of the addition amount of alloying elements in the Al-Si series alloy is solved by combining micro-alloying and preparation process technology.

Description

Technical Field

[0001] This invention discloses an Al-Si alloy thin strip and its preparation process, belonging to the field of non-ferrous metal material processing. Background Technology

[0002] Al-Si alloys are an indispensable raw material in manufacturing. During the preparation of Al-Si alloys, alloying elements are added to enhance their overall properties. These added alloying elements play a crucial role in strengthening the α-Al matrix. For example, adding alloying elements such as Mg and Mn to Al-Si alloys not only strengthens them but also imparts properties such as wear resistance, heat resistance, and a low coefficient of thermal expansion.

[0003] In Al-Si alloys, the addition of Mg forms microparticles, improving the microstructure and increasing the alloy's hardness. These alloying particles not only significantly refine the matrix structure but also reduce the size and quantity of Al-Si hypoeutectic, resulting in a more uniform and stable microstructure.

[0004] To ensure that the quantity and size of primary silicon in the alloy meet the requirements, Mn can be introduced for regulation. Homogenization treatment of aluminum-silicon alloys with different Mn contents improves their mechanical properties. During the homogenization process, the precipitation of Mn-containing dispersed phase particles effectively enhances the overall performance and processing properties of Al-Si alloys.

[0005] In Al-Si alloys, Fe is an element with dual properties, and its content must be strictly controlled to ensure quality. A suitable Fe content can improve the alloy's high-temperature resistance, hardness, and other properties. However, when the Fe content is too high, due to the hardness and brittleness of iron, coarse needle-like structures are easily formed, which not only severely weakens the matrix structure but also leads to a sharp decline in the alloy's properties.

[0006] Furthermore, the addition of Ag to Al-Si alloys gives aluminum alloy strips a superior appearance, making them brighter and more upscale; it also enhances corrosion resistance, effectively protecting the aluminum alloy strips from external oxidation and corrosion. In addition, it improves electrical conductivity, weldability, and environmental friendliness.

[0007] Determining the amount of alloying elements to be added to Al-Si alloys is a key technical issue restricting their further development. This invention discloses an Al-Si alloy strip and its preparation process, mainly through a combination of microalloying and preparation technology to prepare Al-Si alloy strips with good comprehensive properties. The outstanding advantages are excellent 90° bending performance, corrosion resistance, and other comprehensive properties, making it suitable for downstream customers' processing. Summary of the Invention

[0008] In view of this, the present invention discloses an Al-Si alloy thin strip and its preparation process.

[0009] This invention provides an Al-Si alloy strip with the following chemical composition and mass percentage: Si≤0.8%, Mg≤0.15%, Mn>1.5%, Fe≤0.5%, Ag≥0.1%, and the balance being Al and unavoidable impurities.

[0010] This invention also provides a reasonable process for preparing Al-Si alloy thin strips, comprising the following steps:

[0011] (1) Heating: Place aluminum alloy ingots with chemical composition conforming to Si≤0.8%, Mg≤0.15%, Mn>1.5%, Fe≤0.5%, Ag≥0.1%, with the balance being Al and unavoidable impurities into a heating furnace and heat to 560℃, and hold at the temperature for 2~3min / mm.

[0012] (2) Hot rolling: After exiting the furnace, hot rolling begins, with a reduction rate of ≥25%, rolling from 20mm to a thickness of ≥7mm to produce a rough billet;

[0013] (3) Cold rolling: The hot-rolled billet is cold-rolled to prepare an intermediate billet with a reduction rate of ≥15% and a thickness of ≥4.0mm;

[0014] (4) Stress-relieving annealing: Place the cold-rolled intermediate billet into an annealing furnace, heat to ≥250℃, and anneal for ≥60min;

[0015] (5) Secondary cold rolling: The intermediate billet after annealing is cold rolled to prepare a reduction rate of ≥25% and a thickness of ≤0.4mm. After shearing and trimming, a thin strip is obtained.

[0016] The aluminum alloy strip provided by this invention has good dimensional accuracy, excellent 90° bending performance, corrosion resistance and other comprehensive properties, and is of good performance for downstream customers to process and use. Detailed Implementation

[0017] The present invention will be further described below with reference to the embodiments.

[0018] Example 1

[0019] An Al-Si alloy thin strip and its preparation process include the following steps:

[0020] (1) Heating: The aluminum alloy ingot with chemical composition of Si 0.6%, Mg 0.1%, Mn 1.55%, Fe 0.3%, Ag 0.35%, and the balance being Al and unavoidable impurities is placed in a heating furnace and heated to 560℃. The ingot thickness is 20mm, and it is held at 3min / mm for 60min.

[0021] (2) Hot rolling: After exiting the furnace, hot rolling begins. The rolling reduction rates for the three passes are 30%, 30%, and 26%, respectively, rolling from 20mm to a thickness of 7.3mm to produce a rough billet.

[0022] (3) Cold rolling: The hot-rolled billet is cold-rolled with a reduction rate of 16% in each of the three rolling passes, from 7.3 mm to 4.3 mm thickness, to prepare an intermediate billet;

[0023] (4) Stress-relieving annealing: The cold-rolled intermediate billet is placed in an annealing furnace, heated to 300℃, and annealed for 65 minutes;

[0024] (5) Secondary cold rolling: The intermediate billet after annealing is cold rolled with a reduction rate of 30-36% in 7 passes, from 4.3mm to 0.27mm thickness, and then sheared and trimmed to obtain a thin strip.

[0025] The reduction amount per pass for preparing the thin strip is shown in Table 1. The dimensional accuracy test results of the thin strip are good, and the 90° bending performance is qualified.

[0026] Table 1

[0027]

Claims

1. An Al-Si alloy strip, the chemical composition and mass percentage of which are: Si≤0.8%, Mg≤0.15%, Mn>1.5%, Fe≤0.5%, Ag≥0.1%, with the balance being Al and unavoidable impurities.

2. The preparation process of an Al-Si alloy thin strip according to claim 1, characterized in that: The aluminum alloy ingot is placed in a heating furnace and heated to 560℃, and held at that temperature for 2-3 minutes per minute.

3. The preparation process of an Al-Si alloy thin strip according to claim 1, characterized in that: The aluminum alloy ingot is taken out of the furnace and hot rolling begins. The reduction rate is ≥25%, and the thickness is rolled from 20mm to ≥7mm to produce a rough billet.

4. The preparation process of an Al-Si alloy thin strip according to claim 1, characterized in that: The hot-rolled billet is cold-rolled to prepare an intermediate billet with a reduction rate of ≥15% and a thickness of ≥4.0mm.

5. The preparation process of an Al-Si alloy thin strip according to claim 1, characterized in that: The cold-rolled intermediate billet is placed in an annealing furnace and heated to a temperature of ≥250℃ for annealing for ≥60 minutes.

6. The preparation process of an Al-Si alloy thin strip according to claim 1, characterized in that: The annealed intermediate billet is cold rolled to a reduction rate of ≥25% and a thickness of ≤0.4mm. After shearing and trimming, a thin strip is obtained.

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