7655 aluminum alloy large-size flat ingot and its manufacturing method
By using high-purity aluminum alloy and specific proportions as raw materials, combined with the combined use of melting furnace and insulation furnace, electromagnetic stirring and Ar-Cl2 mixed gas refining, as well as the use of large-scale low-level crystallizers and wiper devices, the problem of longitudinal shrinkage and rolling surface cracks in the molding process of 7655 aluminum alloy large-scale flat ingots is solved, achieving better surface quality and melt purity.
Patent Information
- Application Number
- CN202411951872.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-04-08
AI Technical Summary
The existing 7655 aluminum alloy large-size flat ingots are prone to longitudinal shrinkage and rolling surface cracks during the molding process, and the surface quality is poor.
High-purity aluminum and specific proportions of Cu, Mg, Zr, Zn, Be are used as smelting raw materials. Through the combined use of a melting furnace and an insulating furnace, combined with electromagnetic stirring and Ar-Cl2 mixed gas refining, large-scale low-level crystallizers are used for the same-level casting, and wiper device and dual Ap online degassing are used during the casting process.
It effectively reduces the longitudinal shrinkage of the ingot, reduces the tendency of cracks on the rolling surface, and improves the surface quality and melt purity of the ingot.
Smart Images
Figure CN119776705A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of a method for manufacturing a large-size flat ingot of 7655 aluminum alloy. Background Art
[0002] 7 series aluminum alloy is a kind of high-strength alloy series. Due to its high strength and good processability, 7 series aluminum alloy is widely used in aviation, aerospace, automobile, shipbuilding and military fields. 7 series aluminum alloy contains zinc and magnesium elements. Zinc is the main alloying element in this series, so the corrosion resistance is quite good. Adding a small amount of magnesium alloy can make the material reach very high strength after heat treatment. Specific applications include aircraft parts, vehicle armor, military pontoons and lifting vehicles. However, the current large-scale flat ingots of 7655 aluminum alloy have problems such as easy cracking and difficulty in forming, more compounds, and poor surface quality. Summary of the invention
[0003] The present invention aims to solve the technical problems that the aluminum alloy ingots for ships prepared by the existing method have longitudinal shrinkage and a high tendency of rolling surface cracks, and provides a method for manufacturing large-size flat ingots of 7655 aluminum alloy.
[0004] The large-size flat ingot of 7655 aluminum alloy is made of 1.5% to 2.1% Cu, 1.8% to 2.7% Mg, 0.08% to 0.15% Zr, 8.7% to 9.7% Zn, 0.0005% Be and the balance Al as smelting raw materials in percentage by mass; and the mass percentage of impurity Si in the large-size flat ingot of 7655 aluminum alloy is less than 0.06%, the mass percentage of Fe is less than 0.08%, the mass percentage of impurity Cr is less than 0.04%, the mass percentage of impurity Mn is less than 0.05%, and the mass percentage of impurity Ni is less than 0.05%.
[0005] The method for manufacturing the large-size flat ingot of 7655 aluminum alloy is implemented according to the following steps:
[0006] 1. Weighing: Weigh high-purity aluminum ingots, aluminum-zirconium master alloy, aluminum-beryllium master alloy, metallic copper, metallic magnesium and metallic zinc according to the mass percentage of 1.5% to 2.1% Cu, 1.8% to 2.7% Mg, 0.08% to 0.15% Zr, 8.7% to 9.7% Zn, 0.0005% Be and the balance Al;
[0007] 2. Prepare aluminum alloy melt: add the high-purity aluminum ingot and aluminum-zirconium master alloy weighed in step 1 into a charging cart, and put them into a smelting furnace through the charging cart. After the materials are partially melted at a temperature of 720° C. to 750° C., add metal copper and metal zinc. After the furnace charge is completely melted, add metal magnesium and aluminum-beryllium master alloy. Then, electromagnetic stirring is performed at a temperature of 720° C. to 750° C. for 20 to 30 minutes to obtain aluminum alloy melt.
[0008] 3. Casting: Under the condition of temperature of 730℃~750℃, the aluminum alloy melt obtained in step 2 is introduced into the holding furnace, under the condition of temperature of 720℃~740℃, Ar-Cl2 mixed gas is introduced, after refining for 30min, it is allowed to stand for 30min to obtain a casting melt; at the temperature of 720℃~740℃, the casting melt liquid level in the holding furnace and the casting melt liquid level in the flow plate are kept at the same level, and then the casting speed is 40mm / min~50mm / min, the casting temperature is 695℃~710℃, and the casting cooling water flow rate is 30m 3 / min~50m 3 / min, a large-scale low-liquid-level crystallizer is used to cast the casting melt at the same level. Double Ap is used for online degassing. The gas pressure of the degassing equipment is 4MPa~5MPa. The filter sheet adopts 30ppi+50ppi ceramic sheet for filtration to produce large-scale flat ingots of 7655 aluminum alloy.
[0009] Beneficial effects of the present invention:
[0010] The advantages of the present invention are as follows: 1. The present invention adopts a melting furnace for melting and adds an Al-Be master alloy at the same time to ensure the purity of the melt; 2. The present invention adopts high-purity aluminum as a feed material, and uses argon gas in the melting furnace for refining and argon-chlorine mixed gas in the holding furnace to refine the melt to strictly control the content of impurity elements Fe, Si and other harmful elements Na, K, H, etc., so as to ensure the purity of the solution and reduce the influence of impurities on the inside of the solution; 3. The present invention adopts a large-scale low-liquid level crystallizer for casting to rebalance the stress distribution of the ingot while ensuring the surface quality of the ingot; 4. The present invention uses a wiper device during the casting process to reduce the longitudinal shrinkage of the ingot and reduce the crack tendency of the rolled surface of the ingot; 5. The present invention uses double Ap for online degassing, and the filter plate adopts imported 30ppi+50ppi ceramic plate for filtering to ensure the degassing and slag removal effect and improve the melt quality.
[0011] The invention is used for manufacturing large-size flat ingots of 7655 aluminum alloy. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 This is a real photo of a large-sized flat ingot of 7655 aluminum alloy prepared in the embodiment;
[0013] Figure 2 A is a SEM image of a large-sized flat ingot of 7655 aluminum alloy prepared in Example;
[0014] Figure 3 B is the SEM image of the large-sized flat ingot of 7655 aluminum alloy prepared in Example. DETAILED DESCRIPTION
[0015] Specific implementation method one: In this implementation method, the large-size flat ingot of 7655 aluminum alloy is made of 1.5% to 2.1% Cu, 1.8% to 2.7% Mg, 0.08% to 0.15% Zr, 8.7% to 9.7% Zn, 0.0005% Be and the remainder Al as smelting raw materials according to their mass percentage; and the mass percentage of impurity Si in the large-size flat ingot of 7655 aluminum alloy is less than 0.06%, the mass percentage of Fe is less than 0.08%, the mass percentage of impurity Cr is less than 0.04%, the mass percentage of impurity Mn is less than 0.05%, and the mass percentage of impurity Ni is less than 0.05%.
[0016] Specific embodiment 2: This embodiment is different from the specific embodiment 1 in that the large-size flat ingot of 7655 aluminum alloy is made of 1.8% Cu, 2.4% Mg, 0.11% Zr, 9.2% Zn, 0.0005% Be and the balance Al as smelting raw materials. The rest is the same as the specific embodiment 1.
[0017] Specific implementation method three: The manufacturing method of the 7655 aluminum alloy large-size flat ingot described in this implementation method is implemented according to the following steps:
[0018] 1. Weighing: Weigh high-purity aluminum ingots, aluminum-zirconium master alloy, aluminum-beryllium master alloy, metallic copper, metallic magnesium and metallic zinc according to the mass percentage of 1.5% to 2.1% Cu, 1.8% to 2.7% Mg, 0.08% to 0.15% Zr, 8.7% to 9.7% Zn, 0.0005% Be and the balance Al;
[0019] 2. Prepare aluminum alloy melt: add the high-purity aluminum ingot and aluminum-zirconium master alloy weighed in step 1 into a charging cart, and put them into a smelting furnace through the charging cart. After the materials are partially melted at a temperature of 720° C. to 750° C., add metal copper and metal zinc. After the furnace charge is completely melted, add metal magnesium and aluminum-beryllium master alloy. Then, electromagnetic stirring is performed at a temperature of 720° C. to 750° C. for 20 to 30 minutes to obtain aluminum alloy melt.
[0020] 3. Casting: Under the condition of temperature of 730℃~750℃, the aluminum alloy melt obtained in step 2 is introduced into the holding furnace, under the condition of temperature of 720℃~740℃, Ar-Cl2 mixed gas is introduced, after refining for 30min, it is allowed to stand for 30min to obtain a casting melt; at the temperature of 720℃~740℃, the casting melt liquid level in the holding furnace and the casting melt liquid level in the flow plate are kept at the same level, and then the casting speed is 40mm / min~50mm / min, the casting temperature is 695℃~710℃, and the casting cooling water flow rate is 30m 3 / min~50m 3 / min, a large-scale low-liquid-level crystallizer is used to cast the casting melt at the same level. Double Ap is used for online degassing. The gas pressure of the degassing equipment is 4MPa~5MPa. The filter sheet adopts 30ppi+50ppi ceramic sheet for filtration to produce large-scale flat ingots of 7655 aluminum alloy.
[0021] Specific embodiment 4: This embodiment is different from specific embodiment 3 in that: Step 1 weighs high-purity aluminum ingots, aluminum-zirconium master alloy, aluminum-beryllium master alloy, metal copper, metal magnesium and metal zinc as smelting raw materials according to mass percentages of 1.8% Cu, 2.4% Mg, 0.11% Zr, 9.2% Zn, 0.0005% Be and the balance Al. The rest is the same as specific embodiment 1. The rest is the same as specific embodiment 3.
[0022] Specific implementation method 5: This implementation method is different from specific implementation method 3 or 4 in that the mass purity of the high-purity aluminum ingot in step 1 is 99.99%. The rest is the same as specific implementation method 3 or 4.
[0023] Specific implementation method 6: This implementation method is different from the specific implementation methods 3 to 5 in that: after the material is partially melted in step 2, the metal zinc and the metal copper are immersed in the molten body. The rest is the same as the specific implementation methods 3 to 5.
[0024] Specific embodiment 7: This embodiment differs from any one of specific embodiments 3 to 6 in that: the rate of introducing the Ar-Cl2 mixed gas in step 3 is 0.15m 3 / min~0.25m 3 / min. The rest is the same as any one of the third to sixth embodiments.
[0025] Specific implementation eight: This implementation differs from specific implementations three to seven in that the casting in step three adopts large-scale, low-liquid-level, and same-level casting. The rest is the same as specific implementations three to seven.
[0026] Specific embodiment 9: This embodiment is different from any one of specific embodiments 3 to 8 in that: in step 3, the casting speed is 50 mm / min, the casting temperature is 700°C, and the casting cooling water flow rate is 35 m 3 The casting is carried out under the condition of 1000 rpm / min. The rest is the same as any one of the third to eighth embodiments.
[0027] Specific embodiment 10: This embodiment differs from specific embodiments 3 to 9 in that in step 3, a scraper is used to block excess cooling water during the casting process, and the water baffle is fixed below the crystallizer to separate the cooling water from the ingot. The rest is the same as specific embodiments 3 to 9.
[0028] The content of the present invention is not limited to the content of the above-mentioned embodiments. The combination of one or several specific embodiments can also achieve the purpose of the invention.
[0029] Example:
[0030] The manufacturing method of 7655 aluminum alloy large-size flat ingot is characterized in that the manufacturing method of 7655 aluminum alloy large-size flat ingot is realized according to the following steps:
[0031] 1. Weighing: Weigh high-purity aluminum ingot, aluminum-zirconium master alloy, aluminum-beryllium master alloy, metallic copper, metallic magnesium and metallic zinc according to the mass percentage of 1.8% Cu, 2.4% Mg, 0.11% Zr, 9.2% Zn, 0.0005% Be and the balance Al;
[0032] 2. Prepare aluminum alloy melt: add the high-purity aluminum ingot and aluminum-zirconium master alloy weighed in step 1 into a charging cart, and put them into a smelting furnace through the charging cart. After the materials are partially melted at a temperature of 720°C to 750°C, add metal copper and metal zinc. After the furnace charge is completely melted, add metal magnesium and aluminum-beryllium master alloy. Then, electromagnetic stirring is performed at a temperature of 740°C for 30 minutes to obtain aluminum alloy melt.
[0033] 3. Casting: Under the condition of temperature of 730°C, the aluminum alloy melt obtained in step 2 is introduced into the holding furnace, under the condition of temperature of 730°C, Ar-Cl2 mixed gas is introduced, and after refining for 30 minutes, it is allowed to stand for 30 minutes to obtain a casting melt; at a temperature of 720°C, the casting melt level in the holding furnace and the casting melt level in the flow plate are kept at the same level, and then the casting speed is 50mm / min, the casting temperature is 700°C, and the casting cooling water flow rate is 35m 3 / min, a large-scale low-liquid-level crystallizer is used to cast the casting melt at the same level. Double Ap is used for online degassing. The gas pressure of the degassing equipment is 4MPa-5MPa. The filter sheet adopts 30ppi+50ppi ceramic sheet for filtration to produce large-scale flat ingots of 7655 aluminum alloy.
[0034] Figure 1 This is a real photo of the large-sized flat ingot of 7655 aluminum alloy prepared in this embodiment;
[0035] Figure 2 SEM image A of the large-sized flat ingot of 7655 aluminum alloy prepared in this embodiment;
[0036] Figure 3 SEM image B of the large-sized flat ingot of 7655 aluminum alloy prepared in this embodiment;
[0037] It can be seen from the test diagram that the product prepared by the present invention has good surface quality of the ingot after forming, uniform structure, and reduced crack tendency of the ingot rolling surface.
[0038] The advantages of the present invention are as follows: 1. The present invention adopts a melting furnace for melting and adds an Al-Be master alloy at the same time to ensure the purity of the melt; 2. The present invention adopts high-purity aluminum as a feed material, and uses argon gas in the melting furnace for refining and argon-chlorine mixed gas in the holding furnace to refine the melt to strictly control the content of impurity elements Fe, Si and other harmful elements Na, K, H, etc., so as to ensure the purity of the solution and reduce the influence of impurities on the inside of the solution; 3. The present invention adopts a large-scale low-liquid level crystallizer for casting, which rebalances the stress distribution of the ingot and improves the surface quality of the ingot; 4. The present invention uses a wiper device during the casting process to reduce the longitudinal shrinkage of the ingot and reduce the crack tendency of the rolled surface of the ingot; 5. The present invention uses double Ap for online degassing, and the filter plate adopts imported 30ppi+50ppi ceramic plate for filtration to ensure the degassing and slag removal effect and improve the quality of the melt.
Claims
1. 7655 aluminum alloy large size flat ingot, characterized by The large-size flat ingot of 7655 aluminum alloy is made of 1.5% to 2.1% Cu, 1.8% to 2.7% Mg, 0.08% to 0.15% Zr, 8.7% to 9.7% Zn, 0.0005% Be and the balance Al as smelting raw materials in mass percentage; and the mass percentage of impurity Si in the large-size flat ingot of 7655 aluminum alloy is less than 0.06%, the mass percentage of Fe is less than 0.08%, the mass percentage of impurity Cr is less than 0.04%, the mass percentage of impurity Mn is less than 0.05%, and the mass percentage of impurity Ni is less than 0.05%.
2. The 7655 aluminum alloy large-size flat ingot according to claim 1, characterized in that The large-size flat ingot of 7655 aluminum alloy is made of 1.8% Cu, 2.4% Mg, 0.11% Zr, 9.2% Zn, 0.0005% Be and the balance Al as smelting raw materials in mass percentage.
3. The method for manufacturing a large-sized flat ingot of 7655 aluminum alloy as claimed in claim 1, characterized in that The manufacturing method of 7655 aluminum alloy large size flat ingot is realized by the following steps:
1. Weighing: Weigh high-purity aluminum ingots, aluminum-zirconium master alloy, aluminum-beryllium master alloy, metallic copper, metallic magnesium and metallic zinc according to the mass percentage of 1.5% to 2.1% Cu, 1.8% to 2.7% Mg, 0.08% to 0.15% Zr, 8.7% to 9.7% Zn, 0.0005% Be and the balance Al; 2. Prepare aluminum alloy melt: add the high-purity aluminum ingot and aluminum-zirconium master alloy weighed in step 1 into a charging cart, and put them into a smelting furnace through the charging cart. After the materials are partially melted at a temperature of 720° C. to 750° C., add metal copper and metal zinc. After the furnace charge is completely melted, add metal magnesium and aluminum-beryllium master alloy. Then, electromagnetic stirring is performed at a temperature of 720° C. to 750° C. for 20 to 30 minutes to obtain aluminum alloy melt.
3. Casting: Under the condition of temperature of 730℃~750℃, the aluminum alloy melt obtained in step 2 is introduced into the holding furnace, under the condition of temperature of 720℃~740℃, Ar-Cl2 mixed gas is introduced, after refining for 30min, it is allowed to stand for 30min to obtain a casting melt; at the temperature of 720℃~740℃, the casting melt liquid level in the holding furnace and the casting melt liquid level in the flow plate are kept at the same level, and then the casting speed is 40mm / min~50mm / min, the casting temperature is 695℃~710℃, and the casting cooling water flow rate is 30m 3 / min~50m 3 / min, a large-scale low-liquid-level crystallizer is used to cast the casting melt at the same level. Double Ap is used for online degassing. The gas pressure of the degassing equipment is 4MPa~5MPa. The filter sheet adopts 30ppi+50ppi ceramic sheet for filtration to produce large-scale flat ingots of 7655 aluminum alloy.
4. The method for manufacturing a large-sized flat ingot of 7655 aluminum alloy according to claim 1, characterized in that Step 1: Weigh high-purity aluminum ingots, aluminum-zirconium master alloys, aluminum-beryllium master alloys, metallic copper, metallic magnesium and metallic zinc as smelting raw materials according to mass percentages of 1.8% Cu, 2.4% Mg, 0.11% Zr, 9.2% Zn, 0.0005% Be and the balance Al.
5. The method for manufacturing a large-sized flat ingot of 7655 aluminum alloy according to claim 1, characterized in that The mass purity of the high-purity aluminum ingot in step 1 is 99.99%.
6. The method for manufacturing a large-sized flat ingot of 7655 aluminum alloy according to claim 1, characterized in that Step 2: After the material is partially melted, metallic zinc and metallic copper are immersed into the molten body.
7. The method for manufacturing a large-sized flat ingot of 7655 aluminum alloy according to claim 1, characterized in that Step 3: The rate of introducing Ar-Cl2 mixed gas is 0.15m 3 / min~0.25m 3 / min.
8. The method for manufacturing a large-sized flat ingot of 7655 aluminum alloy according to claim 1, characterized in that Step 3 casting adopts large-scale, low-liquid-level, and same-level casting.
9. The method for manufacturing a large-sized flat ingot of 7655 aluminum alloy according to claim 1, characterized in that Step 3: The casting speed is 50 mm / min, the casting temperature is 700°C and the casting cooling water flow rate is 35 m 3 The casting was carried out under the condition of 1.500 rpm / min.
10. The method for manufacturing a large-sized flat ingot of 7655 aluminum alloy according to claim 1, characterized in that In step three, a scraper is used to block excess cooling water during the casting process. The scraper is fixed in position below the crystallizer to separate the cooling water from the ingot.