Smelting process of high-plasticity Al-Si aluminum alloy

Abstract

The invention discloses a smelting process of a high-plasticity Al-Si aluminum alloy, belongs to the technical field of aluminum alloys, and aims to improve the quality of the Al-Si aluminum alloy, and the technical scheme for solving the problem mainly comprises the following steps: S1, preparing a smelting tool; s2, removing rust, greasy dirt and dust from the aluminum ingot, other alloys and auxiliary materials; s3, smelting; s4, analyzing whether the components in the S3 are qualified or not and whether secondary smelting is needed or not; and S5, after the components are qualified, slagging off is conducted, standing is conducted, and then a product casting starts to be cast. The method is mainly used for improving the quality of the Al-Si series aluminum alloy product.

Description

Technical Field

[0001] The invention relates to a smelting process of a high-plasticity Al-Si series aluminum alloy, belonging to the technical field of aluminum alloys. Background Art

[0002] Aluminum has abundant reserves in my country, and aluminum alloys are light, high-strength, corrosion-resistant, thermally conductive, and have good casting properties and excellent processing properties. They are widely used in aerospace, machinery, weapons, transportation and other fields.

[0003] The mechanical properties of commonly used hypoeutectic Al-Si cast aluminum alloys are not only closely related to the eutectic phase morphology, dendrite size and morphology, but also to the gas and slag content and their amount in the alloy. Therefore, after the aluminum alloy is melted, it is necessary not only to refine the aluminum alloy to degas and remove slag to improve the purity of the alloy solution, but also to modify and refine the solution to refine the dendrites and Si phase and improve the quality of the aluminum alloy.

[0004] However, despite this, the existing relevant technologies are relatively vague about the liquid refining, degassing and slag removal, and liquid modification and refinement process parameters. Especially for aluminum alloy melts with high performance requirements, there is no definitive conclusion on the impact of different refining, refinement and modification process combination parameters and sequences on the performance. Therefore, it is necessary to improve the existing aluminum alloy preparation and smelting process. Summary of the invention

[0005] In order to improve the above technical problems, the present invention provides a smelting process of a high-plasticity Al-Si aluminum alloy to improve the quality and quality of the Al-Si aluminum alloy.

[0006] The present invention provides a smelting process for a high-plasticity Al-Si aluminum alloy, comprising the following steps:

[0007] S1: Preparation of smelting tools: Clean the oxide scale and debris on the surface of the smelting tools needed in the smelting process, and evenly apply paint on the surface of the pressure ladle, overflow tube and spoon. Clean and remove the slag and oxide layer on the surface of the crucible that needs to smelt aluminum alloy, spray the paint evenly on the inner wall of the crucible, and bake it at a baking temperature of 250℃~400℃ for 4h for use;

[0008] S2: Remove rust, oil and dust from the required materials, bake them at a constant temperature of 200°C to 300°C for 4 hours for use, bake hexachloroethane, aluminum rare earth refining agent, AlSr10 master alloy, Al-Zr alloy, and RE in a dry oven at a constant temperature of 200°C to 300°C for 3 hours for use;

[0009] S3: Melting: Add the treated high-purity aluminum ingot into the furnace at a temperature of 720℃~780℃, heat it to 890℃~920℃ after melting, add high-purity titanium, keep it warm for 3h~5h, stir it with a stirring tool for 10s~30s every 15min~30min, add high-purity silicon after the composition is qualified, cool it to 760℃~780℃, keep it warm for 40min to 2h, and use hexachloroethane and high-purity argon to degas and refine the melt for 15min, then skim off the slag to obtain a high-cleanliness alloy melt; cool it to a constant temperature of 710℃~730 ℃, adding pure magnesium and 0.01% to 0.015% AlSr10 master alloy, 0.006% to 0.03% RE, 1.5% Al-Ti-B alloy, 0.01% to 0.1% Al-Zr alloy, and 0.2% Al-Ti-C refiner and stirring evenly; then adding 0.5% to 2.5% of the total amount of aluminum liquid aluminum rare earth refining agent, pressing the hood into the melt to rotate and refine at a uniform speed, standing for 10min-15min, and obtaining an alloy sample; using a degasser to degas for 30min, and when the density equivalent is detected to be ≤0.5, taking out the degassed alloy sample and analyzing its chemical composition;

[0010] S4: Determine whether the chemical composition of the degassed alloy sample is qualified. If unqualified, secondary smelting is required;

[0011] S5: After the ingredients are qualified, remove the slag, let it stand for 10min to 30min, and then start casting the product casting.

[0012] Furthermore, the smelting tools in S1 are all made of ceramic or graphite, and no Fe impurities are introduced.

[0013] Furthermore, after adding 0.01% to 0.015% AlSr10 master alloy, 0.006% to 0.03% RE, 1.5% Al-Ti-B alloy, 0.01% to 0.1% Al-Zr alloy and 0.2% Al-Ti-C refiner to the S3 and stirring evenly, it is necessary to stand for a period of more than 15 minutes, wherein the AlSr10 alloy component content is: Sr is 10%, and the balance is Al; the Al-Ti-B alloy component content is: Ti is 5%, B is 1%, and the balance is Al; the Al-Zr alloy component content is: Zr is 5%, and the balance is Al; the Al-Ti-C refiner component content is: Ti is 1%, C is 0.25%, and the balance is Al.

[0014] Furthermore, the ratio of hexachloroethane to high-purity argon in S3 is 3% to 9%.

[0015] Furthermore, the qualified mass percentage of the chemical composition of the alloy sample in S4 is: 6.0% to 7.5% Si; 0% to 0.15% Fe; 0% to 0.1% Cu; 0% to 0.1% Mg; 0.25% to 0.7% Mg; 0% to 0.1% Zn; the total impurities ≤ 0.15; the balance is Al.

[0016] The above technical scheme is adopted, and the advantages of the present invention are: by treating the surface of the melting tool before melting, the oxide scale and slag on the surface of the melting tool are prevented from melting into the aluminum liquid, which affects the quality of the product; secondly, the degassing and slag removal effect is improved by 20% compared with that of using only hexachloroethane after degassing and refining the melt, and the density equivalent is ≤0.1%; and, due to the use of Ti, + Al-Ti-B + Al-Ti-C + RE + Zr composite refinement, which is different from the previous Ti + Al-Ti-B refinement, the quality and quality of the product are improved. The smelting process of the Al-Si aluminum alloy in the present invention can make the average tensile strength of the Al-Si aluminum alloy reach 368MPa; the average yield strength reaches 281MPa; the average elongation after fracture reaches about 7.52%, compared with the general smelting method, the quality and quality of the entire Al-Si aluminum alloy are improved. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0018] The terms "first", "second", etc. (if any) in the specification and claims of the present invention are used to distinguish similar objects, rather than to describe a specific order or sequence. Even if "second" is used to distinguish before a certain technical feature, it does not necessarily indicate that "first" is present. It should be understood that in the present invention, "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. It should be understood that in the present invention, "multiple" refers to two or more. "And / or" is only a description of the association relationship of associated objects, indicating that three relationships can exist. For example, X and / or Y can represent: X exists alone, X and Y exist at the same time, and Y exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "Containing X, Y and Z", "Containing X, Y, Z" means that X, Y, and Z are all included, "Containing X, Y or Z" means that one of X, Y, and Z is included, and "Containing X, Y and / or Z" means that any one, any two, or three of X, Y, and Z are included.

[0019] Embodiment 1:

[0020] The present invention provides a smelting process for a high-plasticity Al-Si aluminum alloy, comprising the following steps:

[0021] S1: Preparation of smelting tools: Clean the oxide scale and debris on the surface of the smelting tools needed in the smelting process, and evenly apply paint on the surface of the pressure ladle, overflow tube and spoon. Clean and remove the slag and oxide layer on the surface of the crucible that needs to smelt aluminum alloy, spray the paint evenly on the inner wall of the crucible, and bake it at a baking temperature of 250℃~400℃ for 4h for use;

[0022] S2: Remove rust, oil and dust from the required materials, bake them at a constant temperature of 200°C to 300°C for 4 hours for use, bake hexachloroethane, aluminum rare earth refining agent, AlSr10 master alloy, Al-Zr alloy, and RE in a dry oven at a constant temperature of 200°C to 300°C for 3 hours for use;

[0023] S3: Melting: Add the treated high-purity aluminum ingot into the furnace at a temperature of 720℃~780℃, heat it to 890℃~920℃ after melting, add high-purity titanium, keep it warm for 3h~5h, stir it with a stirring tool for 10s~30s every 15min~30min, add high-purity silicon after the composition is qualified, cool it to 760℃~780℃, keep it warm for 40min to 2h, and use hexachloroethane and high-purity argon to degas and refine the melt for 15min, then skim off the slag to obtain a high-cleanliness alloy melt; cool it to a constant temperature of 710℃~730 ℃, adding pure magnesium and 0.01% to 0.015% AlSr10 master alloy, 0.006% to 0.03% RE, 1.5% Al-Ti-B alloy, 0.01% to 0.1% Al-Zr alloy, and 0.2% Al-Ti-C refiner and stirring evenly; then adding 0.5% to 2.5% of the total amount of aluminum liquid aluminum rare earth refining agent, pressing the hood into the melt to rotate and refine at a uniform speed, standing for 10min-15min, and obtaining an alloy sample; using a degasser to degas for 30min, and when the density equivalent is detected to be ≤0.5, taking out the degassed alloy sample and analyzing its chemical composition;

[0024] S4: Determine whether the chemical composition of the degassed alloy sample is qualified. If unqualified, secondary smelting is required;

[0025] S5: After the ingredients are qualified, remove the slag, let it stand for 10min to 30min, and then start casting the product casting.

[0026] The present invention treats the surface of the melting tool before melting to prevent the oxide scale and slag on the surface of the melting tool from melting into the aluminum liquid and affecting the quality of the product; secondly, the melt is degassed and refined by combining hexachloroethane and high-purity argon gas to remove slag, and the degassing and slag removal effect is improved by 20% compared with that of using hexachloroethane alone, and the density equivalent is ≤0.1%; and, due to the use of Ti, + Al-Ti-B + Al-Ti-C + RE + Zr composite refinement, which is different from the previous Ti + Al-Ti-B refinement, the quality of the product is improved. The smelting process of the Al-Si aluminum alloy in the present invention can make the average tensile strength of the Al-Si aluminum alloy reach 368MPa; the average yield strength reaches 281MPa; the average elongation after fracture reaches about 7.52%, and compared with the general smelting method, the quality of the entire Al-Si aluminum alloy is improved.

[0027] The smelting tools in S1 are all made of ceramic or graphite, without introducing Fe impurities.

[0028] Specifically, after adding 0.01% to 0.015% AlSr10 master alloy, 0.006% to 0.03% RE, 1.5% Al-Ti-B alloy, 0.01% to 0.1% Al-Zr alloy and 0.2% Al-Ti-C refiner to the S3 and stirring evenly, it needs to be allowed to stand for more than 15 minutes, wherein the AlSr10 alloy component content is: Sr is 10%, and the balance is Al; the Al-Ti-B alloy component content is: Ti is 5%, B is 1%, and the balance is Al; the Al-Zr alloy component content is: Zr is 5%, and the balance is Al; the Al-Ti-C refiner component content is: Ti is 1%, C is 0.25%, and the balance is Al.

[0029] Specifically, the ratio of hexachloroethane to high-purity argon in S3 is 3% to 9%.

[0030] Specifically, the qualified mass percentage of the chemical composition of the alloy sample in S4 is: 6.0% to 7.5% Si; 0% to 0.15% Fe; 0% to 0.1% Cu; 0% to 0.1% Mg; 0.25% to 0.7% Mg; 0% to 0.1% Zn; the total impurities ≤ 0.15; the balance is Al.

[0031] The parameter comparison table of the Al-Si aluminum alloy of the present invention and the Al-Si aluminum alloy of the general smelting method is shown in Table 1:

[0032]

[0033]

[0034] Table 1

[0035] Embodiment 2:

[0036] Different from Example 1, in this example, the qualified mass percentage of the chemical composition of the alloy sample in S4 is: 6.5% to 7.0% Si; 0.05% to 0.1% Fe; 0.03% to 0.07% Cu; 0.03% to 0.07% Mg; 0.45% to 0.6% Mg; 0.03% to 0.07% Zn; the total impurities ≤ 0.15; the balance is Al.

[0037] Embodiment three:

[0038] Different from Example 1, in this example, the qualified mass percentage of the chemical composition of the alloy sample in S4 is: 6.7% to 6.9% Si; 0.07% to 0.09% Fe; 0.04% to 0.06% Cu; 0.04% to 0.06% Mg; 0.65% to 0.5% Mg; 0.04% to 0.06% Zn; the total impurities ≤ 0.15; the balance is Al.

[0039] In addition to the above-mentioned preferred embodiments, the present invention also has other implementation modes. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection requested by the present invention.

Claims

1. A smelting process for a high plasticity Al-Si aluminum alloy, characterized in that: The following steps are involved: S1: Preparation of smelting tools: Clean the oxide scale and debris on the surface of the smelting tools needed in the smelting process, and evenly apply paint on the surface of the pressure ladle, overflow tube and spoon. Clean and remove the slag and oxide layer on the surface of the crucible that needs to smelt aluminum alloy, spray the paint evenly on the inner wall of the crucible, and bake it at a baking temperature of 250℃~400℃ for 4h for use; S2: Remove rust, oil and dust from the required materials, bake them at a constant temperature of 200°C to 300°C for 4 hours for use, bake hexachloroethane, aluminum rare earth refining agent, AlSr10 master alloy, Al-Zr alloy, and RE in a dry oven at a constant temperature of 200°C to 300°C for 3 hours for use; S3: Melting: Add the treated high-purity aluminum ingot into the furnace at a temperature of 720℃~780℃, heat it to 890℃~920℃ after melting, add high-purity titanium, keep it warm for 3h~5h, stir it with a stirring tool for 10s~30s every 15min~30min, add high-purity silicon after the composition is qualified, cool it to 760℃~780℃, keep it warm for 40min to 2h, and use hexachloroethane and high-purity argon to degas and refine the melt for 15min, then skim off the slag to obtain a high-cleanliness alloy melt; cool it to a constant temperature of 710℃~730 ℃, adding pure magnesium and 0.01% to 0.015% AlSr10 master alloy, 0.006% to 0.03% RE, 1.5% Al-Ti-B alloy, 0.01% to 0.1% Al-Zr alloy, and 0.2% Al-Ti-C refiner and stirring evenly; then adding 0.5% to 2.5% of the total amount of aluminum liquid aluminum rare earth refining agent, pressing the hood into the melt to rotate and refine at a uniform speed, standing for 10min-15min, and obtaining an alloy sample; using a degasser to degas for 30min, and when the density equivalent is detected to be ≤0.5, taking out the degassed alloy sample and analyzing its chemical composition; S4: Determine whether the chemical composition of the degassed alloy sample is qualified. If unqualified, secondary smelting is required; S5: After the ingredients are qualified, remove the slag, let it stand for 10min to 30min, and then start casting the product casting.

2. The smelting process of the high plasticity Al-Si aluminum alloy according to claim 1, characterized in that: The smelting tools in S1 are all made of ceramic or graphite.

3. The smelting process of the high plasticity Al-Si aluminum alloy according to claim 1, characterized in that: After adding 0.01% to 0.015% AlSr10 master alloy, 0.006% to 0.03% RE, 1.5% Al-Ti-B alloy, 0.01% to 0.1% Al-Zr alloy and 0.2% Al-Ti-C refiner to the S3 and stirring evenly, it needs to be allowed to stand for more than 15 minutes, wherein the AlSr10 alloy component content is: Sr is 10%, and the balance is Al; the Al-Ti-B alloy component content is: Ti is 5%, B is 1%, and the balance is Al; the Al-Zr alloy component content is: Zr is 5%, and the balance is Al; the Al-Ti-C refiner component content is: Ti is 1%, C is 0.25%, and the balance is Al.

4. The smelting process of the high plasticity Al-Si aluminum alloy according to claim 1, characterized in that: The ratio of hexachloroethane to high-purity argon in S3 is 3% to 9%.

5. The smelting process of the high plasticity Al-Si aluminum alloy according to claim 1, characterized in that: The qualified mass percentage of the chemical composition of the alloy sample in S4 is: 6.0% to 7.5% Si; 0% to 0.15% Fe; 0% to 0.1% Cu; 0% to 0.1% Mg; 0.25% to 0.7% Mg; 0% to 0.1% Zn; the total impurities ≤ 0.15; the balance is Al.

Images