Al-Mg-Zn series aluminum alloy slab ingot containing Er element and manufacturing method of Al-Mg-Zn series aluminum alloy slab ingot

Abstract

The invention discloses an Al-Mg-Zn series aluminum alloy slab ingot containing an Er element and a manufacturing method of the Al-Mg-Zn series aluminum alloy slab ingot, relates to the Al-Mg-Zn series aluminum alloy slab ingot containing the Er element and the manufacturing method of the Al-Mg-Zn series aluminum alloy slab ingot, and aims to solve the problem of corrosion resistance of an existing Al-Mg-Zn series aluminum alloy. The alloy consists of Mn, Mg, Zn, Ti, Zr, Er and the balance of Al. The manufacturing method comprises the following steps: burdening and smelting, smelting a pure aluminum ingot, metal Zn, metal Mg, Al-Mn intermediate alloy, Al-Ti intermediate alloy and Al-Zr intermediate alloy, adding Al-Er intermediate alloy at 780 DEG C or above, keeping the temperature at 780 DEG C or above for 20 minutes, stirring, keeping the temperature twice, stirring twice, heating to 780-800 DEG C to obtain a melt, refining, and finally casting. The heat stability and corrosion resistance of the alloy are improved, and the tensile strength and hardness are enhanced. The method is applied to the field of aluminum alloy.

Description

Technical Field

[0001] The invention relates to an Al-Mg-Zn aluminum alloy flat ingot containing Er element and a manufacturing method thereof. Background Art

[0002] Aluminum-magnesium-zinc alloy (Al-Mg-Zn) is an important lightweight and high-strength alloy widely used in aviation, aerospace, automobile, electronics and other fields. With the continuous improvement of modern industry's requirements for material performance, the research and application of Al-Mg-Zn alloy has become a hot spot in the field of materials science. Historically, the research on Al-Mg-Zn alloy can be traced back to the early 20th century, when the research focused on the phase diagram and phase relationship of the alloy. With the continuous improvement of the performance requirements of the final product and the continuous emergence of new products, the basic performance requirements for raw materials are also constantly increasing. The existing Al-Mg-Zn aluminum alloy has high strength, but poor corrosion resistance. Summary of the invention

[0003] The object of the present invention is to improve the corrosion resistance problem of the existing Al-Mg-Zn aluminum alloy and to provide an Al-Mg-Zn aluminum alloy slab containing Er element and a method for manufacturing the same.

[0004] The invention discloses an Al-Mg-Zn aluminum alloy flat ingot containing Er element, which is composed of Mn: 0.30-0.60%, Mg: 1.70-2.20%, Zn: 5.3-6.3%, Ti: 0.01-0.05%, Zr: 0.09-0.13%, Er: 0.10-0.25%, Si<0.08%, Fe<0.12%, Cu<0.1% and the balance Al in terms of mass percentage, wherein Si, Fe and Cu are impurity elements.

[0005] The present invention provides a method for manufacturing an Al-Mg-Zn aluminum alloy flat ingot containing Er element as follows:

[0006] 1. Ingredients: according to the mass percentage of each element: Mn: 0.30% to 0.60%, Mg: 1.70% to 2.20%, Zn: 5.3% to 6.3%, Ti: 0.01% to 0.05%, Zr: 0.09% to 0.13%, Er: 0.10% to 0.25% and the balance Al, weigh pure aluminum ingot, metal Zn, metal Mg, Al-Mn master alloy, Al-Ti master alloy, Al-Zr master alloy and Al-Er master alloy;

[0007] 2. Melting:

[0008] Firstly add pure aluminum ingot, Al-Mn master alloy and Al-Zr master alloy to the raw materials weighed in step 1, and when the melt temperature is 680°C, add metal Zn, and then add metal Mg and Al-Ti master alloy when the melt temperature is raised to 720-740°C; add Al-Er master alloy when the melt temperature is greater than 780°C, and then keep the temperature when the melt temperature is raised to >780°C, then stir, and then keep the temperature when the melt temperature is raised to >780°C, then stir, and then raise the melt temperature to 780°C-800°C;

[0009] 3. Casting:

[0010] The melt obtained in step 2 is refined at a temperature of 720°C to 750°C, allowed to stand, and then cast at a casting speed of 45 mm / min to 55 mm / min, a casting temperature of 710°C to 730°C, and a casting cooling water of 40 m 3 / h~60m 3 / h to obtain an alloy ingot with a thickness of 420 mm, a width of 1620 mm and a length of 5000 mm to 6000 mm.

[0011] Adding a trace amount of Er element to Al-Mg-Zn aluminum alloy can significantly refine the cast grains and inhibit recrystallization, thereby improving the alloy's thermal stability and intergranular corrosion resistance, and enhancing tensile strength and hardness. At the same time, it can synergize with Zr element to further improve the comprehensive properties of aluminum alloy. Combined with production practice, this Al-Mg-Zn aluminum alloy flat ingot containing Er element and its manufacturing method are formed.

[0012] Beneficial effects of the present invention:

[0013] Compared with general Al-Mg-Zn alloys, the Er-containing Al-Mg-Zn aluminum alloy flat ingot of the present invention has remarkable grain refinement and recrystallization inhibition effects due to the addition of a trace amount of Er element, which works in coordination with the Zr element. The ingot grain size can reach 1.5 to 2 levels, thereby improving the alloy's thermal stability and corrosion resistance, and enhancing tensile strength and hardness. DETAILED DESCRIPTION

[0014] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any combination of the specific implementation modes.

[0015] Specific implementation method 1: In this implementation method, an Al-Mg-Zn aluminum alloy flat ingot containing Er element is composed of Mn: 0.30~0.60%, Mg: 1.70%~2.20%, Zn: 5.3%~6.3%, Ti: 0.01~0.05%, Zr: 0.09~0.13%, Er: 0.10~0.25%, Si<0.08%, Fe<0.12%, Cu<0.1% and the balance Al in terms of mass percentage.

[0016] Specific embodiment 2: This embodiment is different from the specific embodiment 1 in that the aluminum alloy slab is composed of Mn: 0.50%, Mg: 2.0%, Zn: 5.80%, Ti: 0.025%, Zr: 0.12%, Er: 0.20%, Si < 0.08%, Fe < 0.12%, Cu < 0.1% and the balance Al by mass percentage. The rest is the same as the specific embodiment 1.

[0017] Specific implementation method three: In this implementation method, a method for manufacturing an Al-Mg-Zn aluminum alloy flat ingot containing Er element is as follows:

[0018] 1. Ingredients: according to the mass percentage of each element: Mn: 0.30% to 0.60%, Mg: 1.70% to 2.20%, Zn: 5.3% to 6.3%, Ti: 0.01% to 0.05%, Zr: 0.09% to 0.13%, Er: 0.10% to 0.25% and the balance Al, weigh pure aluminum ingot, metal Zn, metal Mg, Al-Mn master alloy, Al-Ti master alloy, Al-Zr master alloy and Al-Er master alloy;

[0019] 2. Melting:

[0020] Firstly add pure aluminum ingot, Al-Mn master alloy and Al-Zr master alloy to the raw materials weighed in step 1, and when the melt temperature is 680°C, add metal Zn, and then add metal Mg and Al-Ti master alloy when the melt temperature is raised to 720-740°C; add Al-Er master alloy when the melt temperature is greater than 780°C, and then keep the temperature when the melt temperature is raised to >780°C, then stir, and then keep the temperature when the melt temperature is raised to >780°C, then stir, and then raise the melt temperature to 780°C-800°C;

[0021] 3. Casting:

[0022] The melt obtained in step 2 is refined at a temperature of 720°C to 750°C, allowed to stand, and then cast at a casting speed of 45 mm / min to 55 mm / min, a casting temperature of 710°C to 730°C, and a casting cooling water of 40 m 3 / h~60m 3 / h to obtain an alloy ingot with a thickness of 420 mm, a width of 1620 mm and a length of 5000 mm to 6000 mm.

[0023] The stirring in step 2 of this embodiment will cause the melt temperature to drop, so the temperature needs to be raised again to above 780°C.

[0024] Specific embodiment 4: This embodiment differs from specific embodiment 3 in that: Step 1 is to weigh the elements in the following proportions: Mn: 0.50%, Mg: 2.0%, Zn: 5.80%, Ti: 0.025%, Zr: 0.12%, Er: 0.20% and the balance Al. The rest is the same as specific embodiment 3.

[0025] Specific embodiment 5: This embodiment is different from specific embodiment 3 or 4 in that: in step 2, when the melt temperature is raised to 730° C., metal Mg and Al-Ti master alloy are added. The rest is the same as specific embodiment 3 or 4.

[0026] Specific implementation method 6: This implementation method is different from the specific implementation methods 3 to 5 in that: step 2 is kept warm for 20 minutes. The rest is the same as the specific implementation methods 3 to 5.

[0027] Specific embodiment 7: This embodiment differs from specific embodiments 3 to 6 in that: in step 3, an argon-chlorine mixed gas is used for refining for 30 minutes, and the argon-chlorine mixed gas is a mixture of 96% argon and 4% chlorine by molar volume. The rest is the same as specific embodiments 3 to 6.

[0028] Specific implementation example 8: This implementation example is different from specific implementation examples 3 to 7 in that the step 3 is left to stand for 30 minutes. The rest is the same as specific implementation examples 3 to 7.

[0029] Specific embodiment 9: This embodiment is different from specific embodiments 2 to 8 in that the casting speed in step 3 is 50 mm / min. The rest is the same as specific embodiments 2 to 8.

[0030] Specific embodiment 10: This embodiment differs from any one of specific embodiments 2 to 9 in that: in step 3, the casting temperature is 716°C and the casting cooling water is 45m 3 / h. The rest is the same as that of any one of the second to ninth embodiments.

[0031] The following examples are used to verify the beneficial effects of the present invention:

[0032] Embodiment 1: The method for manufacturing the flat ingot of Al-Mg-Zn aluminum alloy containing Er element in this embodiment is carried out according to the following steps:

[0033] 1. Ingredients: According to the mass percentage of each element: Mn: 0.50%, Mg: 2.0%, Zn: 5.80%, Ti: 0.025%, Zr: 0.12%, Er: 0.20%, and the balance is Al. Weigh pure aluminum ingots, metal Zn, metal Mg, Al-Mn master alloy, Al-Ti master alloy, Al-Zr master alloy and Al-Er master alloy;

[0034] 2. Melting:

[0035] A. First add pure aluminum ingot, Al-Mn master alloy and Al-Zr master alloy into the raw materials weighed in step 1, and then add metal Zn when the melt temperature reaches 680°C;

[0036] B. Add metal Mg and Al-Ti master alloy when the melt temperature is 725°C;

[0037] C. Add Al-Er master alloy when the melt temperature is 782°C;

[0038] D. After the melt temperature reaches 785°C and is kept for 20 minutes, stir once;

[0039] E. After the melt temperature reaches 783°C and is kept warm for 20 minutes, stir again;

[0040] F. Raise the melt temperature to 796°C to obtain an aluminum alloy melt.

[0041] 3. Casting

[0042] The melt obtained in step 2 was refined by passing argon chlorine gas at a temperature of 728°C for 30 minutes, allowed to stand for 30 minutes, and then cast at a casting speed of 50 mm / min, a casting temperature of 716°C, and a casting cooling water of 45m 3 / h, an alloy ingot with a thickness of 420 mm, a width of 1620 mm and a length of 5820 mm was obtained.

[0043] Compared with the general Al-Mg-Zn alloy, the Al-Mg-Zn aluminum alloy flat ingot containing Er element in this embodiment has significant grain refinement and recrystallization inhibition effects due to the addition of trace Er element and the synergistic effect with Zr element. The grain size of the ingot can reach 1.5 to 2 levels, thereby improving the thermal stability and corrosion resistance of the alloy, and enhancing the tensile strength and hardness.

Claims

1. An Al-Mg-Zn aluminum alloy flat ingot containing Er element, characterized in that: The aluminum alloy slab is composed of Mn: 0.30-0.60%, Mg: 1.70%-2.20%, Zn: 5.3%-6.3%, Ti: 0.01-0.05%, Zr: 0.09-0.13%, Er: 0.10-0.25%, Si<0.08%, Fe<0.12%, Cu<0.1% and the balance Al in terms of mass percentage.

2. The Al-Mg-Zn aluminum alloy flat ingot containing Er element according to claim 1, characterized in that: The aluminum alloy slab is composed of Mn: 0.50%, Mg: 2.0%, Zn: 5.80%, Ti: 0.025%, Zr: 0.12%, Er: 0.20%, Si < 0.08%, Fe < 0.12%, Cu < 0.1% and the balance Al in terms of mass percentage.

3. The method for manufacturing an Al-Mg-Zn aluminum alloy flat ingot containing Er element as claimed in claim 1, characterized in that The manufacturing method is:

1. Ingredients: according to the mass percentage of each element: Mn: 0.30% to 0.60%, Mg: 1.70% to 2.20%, Zn: 5.3% to 6.3%, Ti: 0.01% to 0.05%, Zr: 0.09% to 0.13%, Er: 0.10% to 0.25% and the balance Al, weigh pure aluminum ingot, metal Zn, metal Mg, Al-Mn master alloy, Al-Ti master alloy, Al-Zr master alloy and Al-Er master alloy; 2. Melting: The raw materials weighed in step 1 are first added with pure aluminum ingot, Al-Mn master alloy, and Al-Zr master alloy. When the melt temperature is 680°C, metal Zn is added. Then, when the melt temperature is raised to 720-740°C, metal Mg and Al-Ti master alloy are added. When the melt temperature is greater than 780°C, Al-Er master alloy is added. Then, when the melt temperature is raised to >780°C, the mixture is kept warm and stirred. When the melt temperature is raised to >780°C, the mixture is kept warm and stirred. The melt temperature is raised to 780°C-800°C.

3. Casting: The melt obtained in step 2 is refined at a temperature of 720°C to 750°C, allowed to stand, and then cast at a casting speed of 45 mm / min to 55 mm / min, a casting temperature of 710°C to 730°C, and a casting cooling water of 40 m 3 / h~60m 3 / h to obtain an alloy ingot with a thickness of 420 mm, a width of 1620 mm and a length of 5000 mm to 6000 mm.

4. The method for manufacturing an Al-Mg-Zn aluminum alloy flat ingot containing Er element according to claim 1, characterized in that: Step 1: Weigh the elements according to the mass percentage of Mn: 0.50%, Mg: 2.0%, Zn: 5.80%, Ti: 0.025%, Zr: 0.12%, Er: 0.20% and the balance Al.

5. The method for manufacturing an Al-Mg-Zn aluminum alloy flat ingot containing Er element according to claim 1, characterized in that: Step 2: When the melt temperature is raised to 730°C, metal Mg and Al-Ti master alloy are added.

6. The method for manufacturing an Al-Mg-Zn aluminum alloy flat ingot containing Er element according to claim 1, characterized in that: Step 2: Keep warm for 20 minutes.

7. The method for manufacturing an Al-Mg-Zn aluminum alloy flat ingot containing Er element according to claim 1, characterized in that: In step 3, an argon-chlorine mixed gas is used for refining for 30 minutes. The argon-chlorine mixed gas is a mixture of 96% argon and 4% chlorine by molar volume.

8. The method for manufacturing an Al-Mg-Zn aluminum alloy flat ingot containing Er element according to claim 1, characterized in that: In step 3, let stand for 30 minutes.

9. The method for manufacturing an Al-Mg-Zn aluminum alloy flat ingot containing Er element according to claim 1, characterized in that: Step 3: The casting speed is 50 mm / min.

10. The method for manufacturing an Al-Mg-Zn aluminum alloy flat ingot containing Er element according to claim 1, characterized in that: Step 3: Casting temperature is 716℃, casting cooling water is 45m 3 / h.