Corrosion-resistant aluminum alloy and heat treatment method thereof

Abstract

The invention relates to the field of aluminum alloy preparation, in particular to a corrosion-resistant aluminum alloy and a preparation method thereof. The preparation method of the corrosion-resistant aluminum alloy comprises the three steps of S1, aluminum alloy smelting, S2, spray forming and S3, heat treatment. The aluminum alloy with high corrosion resistance is prepared by screening the metal element composition proportion of the aluminum alloy and innovating and optimizing the heat treatment process. The material is suitable for industrial fields such as various complex corrosive environments, and especially can be used as a novel aeronautical material.

Description

Technical Field

[0001] The present invention relates to the field of aluminum alloy preparation, and particularly relates to a corrosion-resistant aluminum alloy and a preparation method thereof. Background Art

[0002] Aluminum alloy is an alloy material obtained by adding a certain amount of other alloying elements based on aluminum. Aluminum alloy not only retains the performance advantages of aluminum, but also obtains better physical and mechanical properties and hot formability, such as high strength, good casting performance and plastic processing performance, good electrical and thermal conductivity, corrosion resistance and weldability. These characteristics make aluminum alloy widely used in many fields, including automobiles, aerospace, construction, power electronics and new energy. With the increasing global demand for energy conservation, emission reduction and lightweight, the demand for aluminum alloy is also continuously increasing, and its applications in fields such as automotive lightweight, aircraft lightweight and energy transformation are becoming more and more extensive. With the improvement of global environmental awareness, the aluminum alloy industry has also begun to pay attention to green environmental protection. As a recyclable material, aluminum alloy has high environmental protection value. By promoting the recycling and reuse of aluminum alloy, the dependence on primary aluminum ore can be reduced, and the energy consumption and environmental pollution in the production process can be lowered.

[0003] However, the corrosion resistance of aluminum alloy is prone to corrosion in harsh environments (such as marine, humid and acidic environments), affecting its service life and reliability. Traditional aluminum alloy heat treatment methods mostly improve the performance of aluminum alloy by means of temperature control, time adjustment and alloy element addition. However, in actual applications, there are still many deficiencies in the heat treatment process. Therefore, it is necessary to invent a corrosion-resistant aluminum alloy and its heat treatment method. Summary of the Invention

[0004] Aiming at the above existing technical problems, the present invention aims to provide a corrosion-resistant aluminum alloy and a heat treatment method thereof. The preparation method of this aluminum alloy is to screen the composition ratio of aluminum alloy metal elements and innovate and optimize the heat treatment process to prepare an aluminum alloy with high corrosion resistance, which is suitable for high-demand industrial applications such as aviation, automobiles and electronics.

[0005] The present invention discloses a preparation method of a corrosion-resistant aluminum alloy, including the following preparation steps:

[0006] S1 Aluminum alloy melting: Add aluminum, calcium, zinc, manganese, tin, copper and titanium into the furnace in sequence, and then heat up for melting. After all the metals are completely dissolved, a uniform liquid alloy is formed;

[0007] S2 Spray forming: Spray the liquid alloy obtained in step S1 into a metal mold by using spray forming technology to obtain the initial aluminum alloy;

[0008] S3 Heat treatment: Add the initial aluminum alloy obtained in S2 to a heat treatment furnace, introduce nitrogen gas into the heat treatment furnace, control the heating rate during heating, heat it until the initial aluminum alloy dissolves to form a uniform solid solution and then hold the temperature; after the holding ends, introduce hydrogen gas into the heat treatment furnace for quenching treatment, control the cooling rate of the quenching treatment, and after the quenching treatment ends, put the aluminum alloy after quenching treatment into an aging treatment device, introduce nitrogen gas and ethane gas, then set the temperature and artificial aging treatment time of the aging treatment device, and after the artificial aging treatment ends, perform natural aging treatment. During natural aging treatment, introduce oxygen gas into the aging treatment device, and after the natural aging treatment ends, obtain a corrosion-resistant aluminum alloy.

[0009] Preferably, in the aluminum alloy melting step of S1, the mass percentages of aluminum, calcium, zinc, manganese, tin, copper, and titanium are 96.5 - 97.0%, 2.0 - 2.5%, 0.3 - 0.5%, 0.2 - 0.4%, 0.1 - 0.15%, 0.1 - 0.35%, and 0.05 - 0.1% in sequence.

[0010] Preferably, in the heat treatment step of S3, the heating rate of the heat treatment furnace is 1 - 3 °C / min.

[0011] Preferably, in the heat treatment step of S3, the holding temperature of the heat treatment furnace is 450 - 500 °C; the holding time of the heat treatment furnace is 2 - 3 h.

[0012] Preferably, in the heat treatment step of S3, the volume ratio of hydrogen gas to nitrogen gas is 1:(5 - 7).

[0013] Preferably, in the heat treatment step of S3, the cooling rate in the quenching treatment is 50 - 60 °C / min.

[0014] Preferably, in the heat treatment step of S3, the ratio of ethane gas to nitrogen gas is 1:(3 - 5).

[0015] Preferably, in the heat treatment step of S3, the artificial aging treatment temperature is 150 - 180 °C; the treatment time is 10 - 15 h.

[0016] Preferably, in the heat treatment step of S3, the volume ratio of oxygen gas to nitrogen gas is 1:(20 - 25).

[0017] A corrosion-resistant aluminum alloy, which is a corrosion-resistant aluminum alloy prepared by any of the above corrosion-resistant aluminum alloy preparation methods.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] The present invention provides a corrosion-resistant aluminum alloy and a preparation method thereof. The preparation method includes three steps: S1 aluminum alloy melting, S2 spray forming, and S3 heat treatment. In the S1 aluminum alloy melting step, the ratio of calcium, zinc, copper, and manganese metal elements is optimized to improve the corrosion resistance of the aluminum alloy; the added tin element can further improve the oxidation resistance of the aluminum alloy, and the titanium element can improve the grain refinement and mechanical properties of the aluminum alloy. In the S2 spray forming step, because the cooling rate of spray forming is relatively fast, a relatively uniform microstructure can be formed in the initial solidification stage, providing a good basis for subsequent heat treatment. In the S3 heat treatment step, the precise control of the atmosphere during heat treatment is carried out, and the alloying and microstructure changes of the aluminum alloy are optimized by adjusting the ratio of gases (nitrogen, hydrogen, oxygen, ethane gas). Among them, in the heat treatment stage, nitrogen is mainly used to reduce oxidation and avoid excessive formation of the aluminum alloy surface oxide film; hydrogen is added to form a mixed gas with nitrogen during the quenching treatment to remove trace oxygen in the aluminum alloy and reduce the formation of oxides, thereby improving the purity of the aluminum alloy; in the artificial aging treatment in the aging treatment stage, a mixed gas composed of nitrogen and ethane gas is introduced, which can not only isolate oxygen but also use ethane gas for heating. This treatment can not only improve the mechanical properties of the aluminum alloy but also better protect the surface quality of the aluminum alloy; after the artificial aging treatment is completed, a small amount of oxygen is introduced, and then natural aging treatment is carried out in a normal temperature environment, and the surface hardness and corrosion resistance of the aluminum alloy can be effectively enhanced through trace oxidation.

[0020] The aluminum alloy prepared by the preparation method provided by the present invention has excellent corrosion resistance, providing strong technical support for high-end applications in the fields of automobiles, electronics, especially the aviation field, and has remarkable innovation and practicality. Specific embodiments

[0021] The following embodiments are provided to better understand the present invention further, and are not limited to the best embodiment. They do not limit the content and protection scope of the present invention. Any product that is the same as or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior art features falls within the protection scope of the present invention.

[0022] For those steps or conditions not specified in the embodiments, the operations or conditions of the conventional experimental steps described in the literature in this field can be followed. For reagents or instruments not specified by the manufacturer, they are all conventional reagent products that can be obtained through commercial purchase.

[0023] Example 1: A preparation method of a corrosion-resistant aluminum alloy includes the following steps:

[0024] S1 Aluminum alloy melting: Add 96.5% aluminum, 2.5% calcium, 0.5% zinc, 0.2% manganese, 0.1% tin, 0.1% copper, and 0.1% titanium into the furnace in sequence, then heat up to 700 °C for melting. After all the metals are completely dissolved, a uniform liquid alloy is formed;

[0025] S2 Spray forming: Spray the liquid alloy obtained in step S1 into a metal mold by using spray forming technology to obtain the initial aluminum alloy;

[0026] S3 Heat treatment: Add the initial aluminum alloy obtained in S2 to a heat treatment furnace, introduce nitrogen into the heat treatment furnace, control the heating rate during heating at 1 °C / min, heat to 450 °C to dissolve the initial aluminum alloy to form a uniform solid solution, and then hold at 450 °C for 2 h; after the holding is completed, introduce hydrogen into the heat treatment furnace for quenching treatment, where the volume ratio of hydrogen to nitrogen is 1:5, control the cooling rate of the quenching treatment at 50 °C / min until it cools to room temperature. After the quenching treatment is completed, put the aluminum alloy after quenching treatment into an aging treatment device, introduce nitrogen and ethane gas, the volume ratio of ethane gas to nitrogen is 1:3, then set the temperature of the aging treatment device at 150 °C and the artificial aging treatment time at 10 h. After the artificial aging treatment is completed, perform natural aging treatment. When performing natural aging treatment, introduce oxygen into the aging treatment device, the volume ratio of oxygen to nitrogen is 1:20, the temperature of the natural aging treatment is 25 °C, and the treatment duration is 25 h. After the natural aging treatment is completed, a corrosion-resistant aluminum alloy is obtained.

[0027] Example 2: A method for preparing a corrosion-resistant aluminum alloy, comprising the following steps:

[0028] S1 Aluminum alloy melting: Add 97.0% aluminum, 2.0% calcium, 0.3% zinc, 0.2% manganese, 0.1% tin, 0.35% copper, and 0.05% titanium into the furnace in sequence, then heat up to 700 °C for melting. After all the metals are completely dissolved, a uniform liquid alloy is formed;

[0029] S2 Spray forming: Spray the liquid alloy obtained in step S1 into a metal mold by using spray forming technology to obtain the initial aluminum alloy;

[0030] S3 Heat treatment: Add the initial aluminum alloy obtained in S2 to a heat treatment furnace, introduce nitrogen gas into the heat treatment furnace, control the heating rate during heating at 1.5 °C / min, heat to 460 °C to dissolve the initial aluminum alloy to form a uniform solid solution, and then hold at 460 °C for 2.2 h; after the holding is completed, introduce hydrogen gas into the heat treatment furnace for quenching treatment, where the volume ratio of hydrogen gas to nitrogen gas is 1:5, control the cooling rate of the quenching treatment at 52 °C / min until it cools to room temperature. After the quenching treatment is completed, put the aluminum alloy after quenching treatment into an aging treatment device, introduce nitrogen gas and ethane gas, where the volume ratio of ethane gas to nitrogen gas is 1:3, then set the temperature of the aging treatment device at 155 °C and the artificial aging treatment time at 11 h. After the artificial aging treatment is completed, conduct natural aging treatment. During natural aging treatment, introduce oxygen gas into the aging treatment device, where the volume ratio of oxygen gas to nitrogen gas is 1:20, the temperature of natural aging treatment is 25 °C, and the treatment duration is 25 h. After the natural aging treatment is completed, a corrosion-resistant aluminum alloy is obtained.

[0031] Example 3: A method for preparing a corrosion-resistant aluminum alloy, comprising the following steps:

[0032] S1 Aluminum alloy melting: Add 96.6% aluminum, 2.4% calcium, 0.45% zinc, 0.25% manganese, 0.11% tin, 0.13% copper, and 0.06% titanium to a furnace in sequence, and then heat to 700 °C for melting. After all metals are completely dissolved, a uniform liquid alloy is formed;

[0033] S2 Spray forming: Spray the liquid alloy obtained in step S1 into a metal mold using spray forming technology to obtain an initial aluminum alloy;

[0034] S3 Heat treatment: Add the initial aluminum alloy obtained in S2 to a heat treatment furnace, introduce nitrogen gas into the heat treatment furnace, control the heating rate during heating at 2.0 °C / min, heat to 470 °C to dissolve the initial aluminum alloy to form a uniform solid solution, and then hold at 470 °C for 2.4 h; after the holding is completed, introduce hydrogen gas into the heat treatment furnace for quenching treatment, where the volume ratio of hydrogen gas to nitrogen gas is 1:5, control the cooling rate of the quenching treatment at 54 °C / min until it cools to room temperature. After the quenching treatment is completed, put the aluminum alloy after quenching treatment into an aging treatment device, introduce nitrogen gas and ethane gas, where the volume ratio of ethane gas to nitrogen gas is 1:3, then set the temperature of the aging treatment device at 160 °C and the artificial aging treatment time at 12 h. After the artificial aging treatment is completed, conduct natural aging treatment. During natural aging treatment, introduce oxygen gas into the aging treatment device, where the volume ratio of oxygen gas to nitrogen gas is 1:20, the temperature of natural aging treatment is 25 °C, and the treatment duration is 25 h. After the natural aging treatment is completed, a corrosion-resistant aluminum alloy is obtained.

[0035] Example 4: A method for preparing a corrosion-resistant aluminum alloy, comprising the following steps:

[0036] S1 Aluminum alloy melting: Add 96.7% aluminum, 2.3% calcium, 0.4% zinc, 0.3% manganese, 0.12% tin, 0.11% copper, and 0.07% titanium into the furnace in sequence, then heat up to 700 °C for melting. After all the metals are completely dissolved, a uniform liquid alloy is formed;

[0037] S2 Spray forming: Spray the liquid alloy obtained in step S1 into a metal mold by using spray forming technology to obtain a primary aluminum alloy;

[0038] S3 Heat treatment: Add the primary aluminum alloy obtained in S2 into a heat treatment furnace, introduce nitrogen into the heat treatment furnace, control the heating rate during heating to be 2.5 °C / min, heat to 480 °C to dissolve the primary aluminum alloy to form a uniform solid solution, and then hold at 480 °C for 2.4 h; after the holding ends, introduce hydrogen into the heat treatment furnace for quenching treatment, where the volume ratio of hydrogen to nitrogen is 1:5, control the cooling rate of the quenching treatment to be 54 °C / min until it cools to room temperature. After the quenching treatment ends, put the aluminum alloy after quenching treatment into an aging treatment device, introduce nitrogen and ethane gas, the volume ratio of ethane gas to nitrogen is 1:3, then set the temperature of the aging treatment device to 170 °C and the artificial aging treatment time to 13 h. After the artificial aging treatment ends, conduct natural aging treatment. During natural aging treatment, introduce oxygen into the aging treatment device, the volume ratio of oxygen to nitrogen is 1:20, the temperature of natural aging treatment is 25 °C, and the treatment duration is 25 h. After the natural aging treatment ends, a corrosion-resistant aluminum alloy is obtained.

[0039] Example 5: A method for preparing a corrosion-resistant aluminum alloy, comprising the following steps:

[0040] S1 Aluminum alloy melting: Add 96.8% aluminum, 2.1% calcium, 0.35% zinc, 0.35% manganese, 0.13% tin, 0.21% copper, and 0.08% titanium into the furnace in sequence, then heat up to 700 °C for melting. After all the metals are completely dissolved, a uniform liquid alloy is formed;

[0041] S2 Spray forming: Spray the liquid alloy obtained in step S1 into a metal mold by using spray forming technology to obtain a primary aluminum alloy;

[0042] S3 Heat treatment: Add the initial aluminum alloy obtained in S2 to a heat treatment furnace, introduce nitrogen gas into the heat treatment furnace, control the heating rate during heating at 2.5 °C / min, heat to 480 °C to dissolve the initial aluminum alloy to form a uniform solid solution, and then hold at 480 °C for 2.4 h; after the holding ends, introduce hydrogen gas into the heat treatment furnace for quenching treatment, where the volume ratio of hydrogen gas to nitrogen gas is 1:5, control the cooling rate of the quenching treatment at 54 °C / min until it cools to room temperature. After the quenching treatment ends, put the quenched aluminum alloy into an aging treatment device, introduce nitrogen gas and ethane gas, where the volume ratio of ethane gas to nitrogen gas is 1:3, then set the temperature of the aging treatment device at 170 °C and the artificial aging treatment time at 13 h. After the artificial aging treatment ends, conduct natural aging treatment. During the natural aging treatment, introduce oxygen gas into the aging treatment device, where the volume ratio of oxygen gas to nitrogen gas is 1:20, the temperature of the natural aging treatment is 25 °C, and the treatment duration is 25 h. After the natural aging treatment ends, obtain the corrosion-resistant aluminum alloy.

[0043] Example 6: A method for preparing a corrosion-resistant aluminum alloy, comprising the following steps:

[0044] S1 Aluminum alloy melting: Add 96.82% aluminum, 2.3% calcium, 0.4% zinc, 0.3% manganese, 0.11% copper, and 0.07% titanium to a furnace in sequence, and then heat up to 700 °C for melting. After all the metals are completely dissolved, form a uniform liquid alloy;

[0045] S2 Spray forming: Use spray forming technology to spray the liquid alloy obtained in step S1 into a metal mold to obtain an initial aluminum alloy;

[0046] S3 Heat treatment: Add the initial aluminum alloy obtained in S2 to a heat treatment furnace, introduce nitrogen gas into the heat treatment furnace, control the heating rate during heating at 2.5 °C / min, heat to 480 °C to dissolve the initial aluminum alloy to form a uniform solid solution, and then hold at 480 °C for 2.4 h; after the holding ends, introduce hydrogen gas into the heat treatment furnace for quenching treatment, where the volume ratio of hydrogen gas to nitrogen gas is 1:5, control the cooling rate of the quenching treatment at 54 °C / min until it cools to room temperature. After the quenching treatment ends, put the quenched aluminum alloy into an aging treatment device, introduce nitrogen gas and ethane gas, where the volume ratio of ethane gas to nitrogen gas is 1:3, then set the temperature of the aging treatment device at 170 °C and the artificial aging treatment time at 13 h. After the artificial aging treatment ends, conduct natural aging treatment. During the natural aging treatment, introduce oxygen gas into the aging treatment device, where the volume ratio of oxygen gas to nitrogen gas is 1:20, the temperature of the natural aging treatment is 25 °C, and the treatment duration is 25 h. After the natural aging treatment ends, obtain the corrosion-resistant aluminum alloy.

[0047] Example 7: A preparation method of a corrosion-resistant aluminum alloy, comprising the following steps:

[0048] S1 Aluminum alloy melting: Add 96.77% aluminum, 2.3% calcium, 0.4% zinc, 0.3% manganese, 0.12% tin and 0.11% copper into the furnace in sequence, then heat up to 700 °C for melting. After all the metals are completely dissolved, a uniform liquid alloy is formed;

[0049] S2 Spray forming: Spray the liquid alloy obtained in step S1 into a metal mold by using spray forming technology to obtain a primary aluminum alloy;

[0050] S3 Heat treatment: Add the primary aluminum alloy obtained in S2 to a heat treatment furnace, introduce nitrogen into the heat treatment furnace, control the heating rate during heating to be 2.5 °C / min, heat to 480 °C to dissolve the primary aluminum alloy to form a uniform solid solution, and then hold at 480 °C for 2.4 h; After the heat preservation is completed, introduce hydrogen into the heat treatment furnace for quenching treatment, where the volume ratio of hydrogen to nitrogen is 1:5, control the cooling rate of the quenching treatment to be 54 °C / min until it cools to room temperature. After the quenching treatment is completed, put the aluminum alloy after quenching treatment into an aging treatment device, introduce nitrogen and ethane gas, and the volume ratio of ethane gas to nitrogen is 1:3. Then set the temperature of the aging treatment device to 170 °C and the artificial aging treatment time to 13 h. After the artificial aging treatment is completed, carry out natural aging treatment. When carrying out natural aging treatment, introduce oxygen into the aging treatment device, and the volume ratio of oxygen to nitrogen is 1:20. The temperature of natural aging treatment is 25 °C, and the treatment duration is 25 h. After the natural aging treatment is completed, a corrosion-resistant aluminum alloy is obtained.

[0051] The corrosion resistance and mechanical properties of the aluminum alloys prepared in Examples 1-7 were tested, and the test results are shown in the following table:

[0052] (1) Corrosion resistance: Adopt the salt spray test (ASTM B117 standard) to test the corrosion situation of each alloy sample in a 72-hour salt spray environment. Quantify the corrosion resistance by evaluating the area and depth of surface corrosion.

[0053] (2) Mechanical properties: Use a tensile testing machine to test the tensile strength, yield strength and elongation. The common standard is ASTM E8 / E8M.

[0054]

[0055] As can be seen from the test results in the above table, the aluminum alloys prepared in Examples 1-5 all have good corrosion resistance. Among them, the aluminum alloy in Example 4 has the best corrosion resistance, and the aluminum alloy prepared in Example 6 has relatively poor corrosion resistance. This indicates that higher calcium and zinc contents may contribute to improving the corrosion resistance of aluminum alloys. Calcium and zinc elements help form a protective oxide film in the alloy, thereby reducing the occurrence of corrosion. The content of tin elements also has a certain impact on the corrosion resistance of aluminum alloys. The aluminum alloy with added tin elements has better corrosion resistance than the aluminum alloy without added tin elements. The mechanical properties of the aluminum alloys prepared in Examples 1-5 are excellent, while the mechanical properties of the aluminum alloy prepared in Example 7 are poor. It can be shown that the titanium element content has a certain impact on the mechanical properties of aluminum alloys.

[0056] Example 8: The preparation method of a corrosion-resistant aluminum alloy is the same as that in Example 4, only changing the volume ratio of hydrogen to nitrogen in the quenching treatment in the S3 heat treatment step, preparing the aluminum alloy under the corresponding volume ratio, and performing performance tests on it. The test results are shown in the following table:

[0057]

[0058] As can be seen from the test data in the above table, the volume ratio of hydrogen to nitrogen affects the corrosion resistance, mechanical properties, and surface hardness of the aluminum alloy product. When the nitrogen ratio increases, the various properties are improved. Among them, when the volume ratio of hydrogen to nitrogen is 1:6.5, the various properties of the prepared aluminum alloy reach the best values.

[0059] Example 9: The preparation method of a corrosion-resistant aluminum alloy is the same as that in Example 4, only changing the volume ratio of ethane gas to nitrogen in the artificial aging treatment in the S3 heat treatment step, preparing the aluminum alloy under the corresponding volume ratio, and performing performance tests on it. The test results are shown in the following table:

[0060]

[0061] As can be seen from the test data in the above table, the volume ratio of ethane gas to nitrogen affects the corrosion resistance, mechanical properties, and surface hardness of the aluminum alloy product. When the nitrogen ratio increases, the various properties are improved. Among them, when the volume ratio of hydrogen to nitrogen is 1:5, the various properties of the prepared aluminum alloy reach the best values.

[0062] Example 10: The preparation method of a corrosion-resistant aluminum alloy is the same as that in Example 4, only changing the volume ratio of oxygen to nitrogen in the natural aging treatment in the S3 heat treatment step, preparing the aluminum alloy under the corresponding volume ratio, and performing performance tests on it. The test results are shown in the following table:

[0063]

[0064] As can be seen from the test data in the above table, the volume ratio of oxygen to nitrogen will affect the corrosion resistance, mechanical properties and surface hardness of the finished aluminum alloy. When the proportion of nitrogen increases, all properties are improved. Among them, when the volume ratio of hydrogen to nitrogen is 1:24, the properties of the prepared aluminum alloy reach the best values.

[0065] As can be seen from the test data in the above table, the volume ratio of oxygen to nitrogen will affect the corrosion resistance, mechanical properties and surface hardness of the finished aluminum alloy. When the proportion of nitrogen increases, all properties are improved. Among them, when the volume ratio of hydrogen to nitrogen is 1:24, the properties of the prepared aluminum alloy reach the best values.

[0066] Obviously, the above embodiments are only examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for preparing a corrosion-resistant aluminum alloy, characterized in that: The following steps are involved: S1 Aluminum alloy smelting: Aluminum, calcium, zinc, manganese, tin, copper and titanium are added into the furnace in sequence, and then the temperature is raised for smelting. After all the metals are completely dissolved, a uniform liquid alloy is formed; S2 spray molding: the liquid alloy obtained in step S1 is sprayed into a metal mold using spray molding technology to obtain an initial aluminum alloy; S3 heat treatment: adding the initial aluminum alloy obtained in S2 to a heat treatment furnace, introducing nitrogen into the heat treatment furnace, controlling the heating rate during the heating process, heating until the initial aluminum alloy is dissolved to form a uniform solid solution, and then keeping the temperature; After the insulation is completed, hydrogen is introduced into the heat treatment furnace for quenching treatment, and the cooling rate of the quenching treatment is controlled. After the quenching treatment is completed, the quenched aluminum alloy is placed in an aging treatment device, and nitrogen and ethane gases are introduced. Then, the temperature of the aging treatment device and the artificial aging treatment time are set. After the artificial aging treatment is completed, natural aging treatment is carried out, and oxygen is introduced into the aging treatment device during the natural aging treatment. After the natural aging treatment is completed, a corrosion-resistant aluminum alloy is obtained.

2. The method for preparing a corrosion-resistant aluminum alloy according to claim 1, characterized in that: In the S1 aluminum alloy smelting step, the mass percentages of aluminum, calcium, zinc, manganese, tin, copper and titanium are 96.5-97.0%, 2.0-2.5%, 0.3-0.5%, 0.2-0.4%, 0.1-0.15%, 0.1-0.35% and 0.05-0.1%, respectively.

3. The method for preparing a corrosion-resistant aluminum alloy according to claim 1, characterized in that: In the S3 heat treatment step, the heating rate of the heat treatment furnace is 1 to 3°C / min.

4. The method for preparing a corrosion-resistant aluminum alloy according to claim 1, characterized in that: In the S3 heat treatment step, the heat treatment furnace is kept at a temperature of 450 to 500° C. and a heat treatment furnace is kept for 2 to 3 hours.

5. The method for preparing a corrosion-resistant aluminum alloy according to claim 1, characterized in that: In the S3 heat treatment step, the volume ratio of hydrogen to nitrogen is 1:(5-7).

6. The method for preparing a corrosion-resistant aluminum alloy according to claim 1, characterized in that: In the S3 heat treatment step, the cooling rate in the quenching treatment is 50 to 60° C. / min.

7. The method for preparing a corrosion-resistant aluminum alloy according to claim 1, characterized in that: In the S3 heat treatment step, the ratio of the ethane gas to the nitrogen gas is 1:(3-5).

8. The method for preparing a corrosion-resistant aluminum alloy according to claim 1, characterized in that: In the S3 heat treatment step, the artificial aging treatment temperature is 150-180° C. and the treatment time is 10-15 hours.

9. The method for preparing a corrosion-resistant aluminum alloy according to claim 1, characterized in that: In the S3 heat treatment step, the volume ratio of oxygen to nitrogen is 1:(20-25).

10. A corrosion-resistant aluminum alloy prepared by the method for preparing a corrosion-resistant aluminum alloy according to any one of claims 1 to 9.

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