Production process of 6061 aluminum alloy super-flat plate

Abstract

The invention relates to a 6061 aluminum alloy super-flat plate production process, and belongs to the technical field of aluminum alloy processing and manufacturing. The aluminum alloy is composed of, by mass, 0.4%-0.80% of Si, smaller than or equal to 0.7% of Fe, 0.15%-0.4% of Cu, smaller than or equal to 0.15% of Mn, 0.8%-1.2% of Mg, smaller than or equal to 0.25% of Zn, 0.04%-0.35% of Cr, smaller than or equal to 0.15% of Ti, smaller than or equal to 0.05% of single impurities, smaller than or equal to 0.15% of the total, and the balance Al. The preparation method comprises the steps of burdening, smelting, refining, casting, saw cutting, surface milling, soaking, hot rolling, edge cutting, solution treatment, straightening, stretching, aging and saw cutting and packaging. By controlling the hot rolling process, the heat treatment solid solution process, the pre-stretching process and the straightening process, on the premise that the machining performance of the plate is guaranteed, the dimensional tolerance of the plate and the flatness of the whole plate are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum alloy processing and manufacturing, and specifically relates to a 6061 aluminum alloy super-flat plate production process. Background Art

[0002] As carbon dioxide emissions from various countries surge, greenhouse gases pose a threat to life systems. Countries around the world have signed a global agreement to reduce greenhouse gas emissions. Aluminum alloy materials have the advantages of low density, excellent welding performance, high hardness and specific strength, good processing performance, good corrosion resistance and high toughness. They have long been widely used in aerospace, transportation, weapons and equipment. As "carbon peak" and "carbon neutrality" become more and more widely concerned topics, lightweighting is also widely used in all walks of life.

[0003] As one of the most commonly used aluminum alloys, 6061T6 aluminum alloy is widely used in the manufacture of aircraft parts, large structural parts, and automotive parts with medium strength and high requirements for plasticity and corrosion resistance due to its good comprehensive properties. During the heat treatment and quenching process of 6061 aluminum alloy plates, due to the temperature gradient between the surface and the center layer of the plate, large internal residual stress will be generated. The traditional T6 heat treatment process is solution quenching-straightening-aging. The internal stress of the plate cannot be significantly reduced through the straightening process, which will cause processing deformation during mechanical processing. Summary of the invention

[0004] In view of this, the present invention discloses a 6061 aluminum alloy super flat plate production process, specifically relates to a 8 to 30 mm aluminum alloy super flat plate production process, the specific scheme is as follows:

[0005] A 6061 aluminum alloy super flat plate production process comprises the following steps:

[0006] S1. Ingredients, according to mass fraction, the ingredients of 6061 aluminum alloy can material in melting and casting are: Si: 0.4-0.80%, Fe≤0.7%, Cu: 0.15-0.4%, Mn:≤0.15%, Mg: 0.8-1.2%, Zn:≤0.25%, Cr: 0.04-0.35%, Ti≤0.15%, single impurity≤0.05%, total≤0.15%, the balance is Al;

[0007] S2. After the alloy is prepared according to the mass percentage in step S1, smelting, furnace refining, online degassing, online filtration, the molten aluminum is cast into an aluminum alloy ingot;

[0008] S3. The ingot is subjected to sawing and milling treatment;

[0009] S4. After sawing and milling, the surface is placed in a push-type heating furnace for heating at a temperature of 500°C for 3 hours;

[0010] S5. The soaked ingot is hot rolled, with 30 passes, to the thickness of the finished hot-rolled plate;

[0011] S6. trimming the plate;

[0012] S7. The hot-rolled aluminum alloy sheet is subjected to a solution treatment at a solution temperature of 535 to 560° C. for a holding time of 30 to 60 min. After the solution treatment, the sheet is subjected to a quenching treatment, and the upper and lower sheet surfaces are subjected to a water-cooled spray quenching;

[0013] S8. Complete plate straightening within 6 hours after quenching;

[0014] S9. Stretching the sheet;

[0015] S10. After the stretching treatment, the aging furnace is aged within 48 hours, the aging temperature is 165-180°C, the heating rate is 25-30°C / h, and the insulation time is 10-12h;

[0016] S11. Cut the aged boards into finished product specifications and package them.

[0017] As a supplement to the technical solution of the present invention, in step S3, the milling surface thickness is 10 mm.

[0018] As a supplement to the technical solution of the present invention, in step S5, the starting rolling temperature is 400-420°C, and the finishing rolling temperature is 300-320°C.

[0019] As a supplement to the technical solution of the present invention, in step S5, the maximum reduction amount of each of the last three rolling passes of the plate is 10 mm.

[0020] As a supplement to the technical solution of the present invention, in step S6, the cutting width is 30 mm.

[0021] As a supplement to the technical solution of the present invention, in step S9, the stretching amount is 0.5-1.0%.

[0022] As a supplement to the technical solution of the present invention, in step S9, stretching is performed within 48 hours after quenching.

[0023] Beneficial effects: The present invention discloses a 6061 aluminum alloy ultra-flat plate production process, which reduces the internal stress and narrows the thickness tolerance range of the finished plate by controlling the pressing amount of the plate in the rolling process and the stretching amount of the plate in the heat treatment process, so as to make the plate thickness closer to the finished size of the later processed parts and effectively reduce the amount of milling in the later processing; by optimizing the heat treatment process of the plate, the flatness of the plate is improved, the amount of mechanical processing in the later use is reduced, and the processing efficiency of the later parts is improved while ensuring that the customer's later mechanical processing does not cause large deformation; by strictly controlling all links of production and optimizing the rolling process and heat treatment process, the flatness and dimensional tolerance of large-size plates can reach a high level, which can meet the use of large-size and high-flatness processed parts and ensure that the plates are not deformed after processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a physical picture of the sample of the present invention. DETAILED DESCRIPTION

[0025] A 6061 aluminum alloy super flat plate production process, the specific production steps are as follows:

[0026] S1. Ingredients, according to mass fraction, the ingredients of 6061 aluminum alloy can material in melting and casting are: Si: 0.4-0.80%, Fe≤0.7%, Cu: 0.15-0.4%, Mn:≤0.15%, Mg: 0.8-1.2%, Zn:≤0.25%, Cr: 0.04-0.35%, Ti≤0.15%, single impurity≤0.05%, total≤0.15%, the balance is Al;

[0027] S2. After the alloy is prepared according to the mass percentage in step S1, smelting, furnace refining, online degassing, online filtration, the molten aluminum is cast into an aluminum alloy ingot;

[0028] S3. The ingot is sawn and milled, with each side milled by 10 mm;

[0029] S4. After sawing and milling, the surface is placed in a push-type heating furnace for heating at a temperature of 500°C for 3 hours;

[0030] S5. The soaked ingot is hot rolled, with 30 hot rolling passes, a starting rolling temperature of 400-420°C, a convexity of 0-0.2% (target value 0.1%), a final rolling temperature of 300-320°C, a maximum reduction of 10 mm during the last three rolling passes of the plate, and hot rolling to the thickness of the finished hot rolled plate;

[0031] S6. Trim the plate, cut 30mm on one side, and ensure there is no crack on the edge of the plate;

[0032] S7. The hot-rolled aluminum alloy sheet is subjected to a solution treatment at a solution temperature of 535 to 560° C. for a holding time of 30 to 60 min. After the solution treatment, the sheet is subjected to a quenching treatment, and the upper and lower sheet surfaces are subjected to a water-cooled spray quenching;

[0033] S8. Complete plate straightening within 6 hours after quenching;

[0034] S9. The plate is stretched within 48 hours after quenching, using a 40MN stretching machine with a stretching amount of 0.5 to 1.0%;

[0035] S10. After the stretching treatment, the aging furnace is aged within 48 hours, the aging temperature is 165-180°C, the heating rate is 25-30°C / h, and the insulation time is 10-12h;

[0036] S11. Cut the aged boards into finished product specifications and package them.

[0037] Embodiment 1:

[0038] S1. Melting, furnace refining, online degassing, online filtering and then casting into aluminum alloy ingots are carried out according to the following aluminum alloy mass percentage ingredients: Si: 0.646%, Fe: 0.47%, Cu: 0.226%, Mg: 1.11%, Zn: 0.02%; Ti: 0.023%; Mn: 0.095%; Cr: 0.3; Al: 97.11%.

[0039] S2. After the alloy mass percentage is prepared in step S1, smelting, furnace refining, online degassing, and online filtration are carried out to cast the aluminum liquid into aluminum alloy ingots; the smelting process is specifically as follows: the amount of each aluminum alloy raw material is calculated, and the prepared iron block, copper block, magnesium block, industrial silicon block and aluminum ingot are respectively transferred into the smelting furnace to melt to a semi-molten state, and then a zinc ingot is added (the zinc ingot can just be completely submerged to prevent burning), and slag is removed to remove the slag on the surface of the aluminum liquid. When the aluminum alloy raw materials are completely melted, the alloy composition is detected. When the composition is qualified, the furnace is smelted at a temperature of 700-760°C, and a chlorine-argon mixed gas is used to refine and slag the melt, and the refining time is 30-45 minutes.

[0040] S3. The ingot is sawn and milled, with each side milled by 10 mm;

[0041] S4. After sawing and milling, the surface is placed in a push-type heating furnace for heating at a temperature of 500°C for 3 hours;

[0042] S5. The soaked ingot is hot rolled, with 30 hot rolling passes, a starting rolling temperature of 400-420°C, a convexity of 0-0.2% (target value 0.1%), a final rolling temperature of 305°C, a maximum reduction of 10 mm per pass in the last 3 passes of the plate, and hot rolling to the thickness of the finished hot rolled plate;

[0043] S6. Trim the plate, cut 30mm on one side, and ensure there is no crack on the edge of the plate;

[0044] S7. The hot-rolled aluminum alloy plate is subjected to a solution treatment, the plate thickness is 15 mm, the solution temperature is 545° C., the holding time is 30 min, and the plate is quenched after the solution treatment, and the upper and lower plate surfaces are water-cooled and spray-quenched, and the water pressure is 1.1 bar;

[0045] S8. Complete the straightening of the plate within 6 hours after quenching, strictly control the unevenness of the plate surface after straightening, and control the transverse flatness of the plate within 0.1mm / m;

[0046] S9. The plate is stretched within 48 hours after quenching, using a 40MN stretching machine with a stretching amount of 0.7%. After stretching, the transverse flatness of the plate is ≤0.2mm / m, and the longitudinal flatness is ≤0.15mm / m;

[0047] S10. After the stretching treatment, the aging furnace is aged within 48 hours, the aging temperature is 170°C, the heating rate is 25-30°C / h, and the insulation time is 10-12h;

[0048] S11. Cut the aged boards into finished product specifications and package them.

[0049] Embodiment 2:

[0050] S1. Melting, furnace refining, online degassing, online filtering and casting into aluminum alloy ingots are carried out according to the following aluminum alloy mass percentage ingredients: Si: 0.599%, Fe: 0.238%, Cu: 0.232%, Mg: 0.96%, Zn: 0.006%; Ti: 0.018%; Mn: 0.093%; Cr: 0.204%; Al: 97.65%.

[0051] S2. After the alloy mass percentage is prepared in step S1, smelting, furnace refining, online degassing, and online filtration are carried out to cast the aluminum liquid into aluminum alloy ingots; the smelting process is specifically as follows: the amount of each aluminum alloy raw material is calculated, and the prepared iron block, copper block, magnesium block, industrial silicon block and aluminum ingot are respectively transferred into the smelting furnace to melt to a semi-molten state, and then a zinc ingot is added (the zinc ingot can just be completely submerged to prevent burning), and slag is removed to remove the slag on the surface of the aluminum liquid. When the aluminum alloy raw materials are completely melted, the alloy composition is detected. When the composition is qualified, the furnace is smelted at a temperature of 700-760°C, and a chlorine-argon mixed gas is used to refine and slag the melt, and the refining time is 30-45 minutes.

[0052] S3. The ingot is sawn and milled, with each side milled by 10 mm;

[0053] S4. After sawing and milling, the surface is placed in a push-type heating furnace for heating at a temperature of 500°C for 3 hours;

[0054] S5. The soaked ingot is hot rolled, with 30 hot rolling passes, a starting rolling temperature of 400-420°C, a convexity of 0-0.2% (target value 0.1%), a final rolling temperature of 305°C, a maximum reduction of 10 mm per pass in the last 3 passes of the plate, and hot rolling to the thickness of the finished hot rolled plate;

[0055] S6. Trim the plate, cut 30mm on one side, and ensure there is no crack on the edge of the plate;

[0056] S7. The hot-rolled aluminum alloy plate is subjected to a solution treatment, the plate thickness is 20 mm, the solution temperature is 545° C., the holding time is 40 min, and the plate is quenched after the solution treatment, and the upper and lower plate surfaces are water-cooled spray quenched, the quenching water high pressure is 0.5-1.0 bar, and the quenching water low pressure is 0.7 bar;

[0057] S8. Complete the straightening of the plate within 6 hours after quenching, strictly control the unevenness of the plate surface after straightening, and control the transverse flatness of the plate within 0.1mm / m;

[0058] S9. The plate is stretched within 48 hours after quenching, using a 40MN stretching machine with a stretching amount of 0.6%. After stretching, the transverse flatness of the plate is ≤0.15mm / m, and the longitudinal flatness is ≤0.15mm / m;

[0059] S10. After the stretching treatment, the aging furnace is aged within 48 hours, the aging temperature is 170°C, the heating rate is 25-30°C / h, and the insulation time is 10-12h;

[0060] S11. Cut the aged boards into finished product specifications and package them.

[0061] Embodiment 3:

[0062] S1. Melting, furnace refining, online degassing, online filtering and casting into aluminum alloy ingots are carried out according to the following aluminum alloy mass percentage ingredients: Si: 0.517%, Fe: 0.497%, Cu: 0.238%, Mg: 0.964%, Zn: 0.01%; Ti: 0.021%; Mn: 0.095%; Cr: 0.288%; Al: 97.37%.

[0063] S2. After the alloy mass percentage is prepared in step S1, smelting, furnace refining, online degassing, and online filtration are carried out to cast the aluminum liquid into aluminum alloy ingots; the smelting process is specifically as follows: the amount of each aluminum alloy raw material is calculated, and the prepared iron block, copper block, magnesium block, industrial silicon block and aluminum ingot are respectively transferred into the smelting furnace to melt to a semi-molten state, and then a zinc ingot is added (the zinc ingot can just be completely submerged to prevent burning), and slag is removed to remove the slag on the surface of the aluminum liquid. When the aluminum alloy raw materials are completely melted, the alloy composition is detected. When the composition is qualified, the furnace is smelted at a temperature of 700-760°C, and a chlorine-argon mixed gas is used to refine and slag the melt, and the refining time is 30-45 minutes.

[0064] S3. The ingot is sawn and milled, with each side milled by 10 mm;

[0065] S4. After sawing and milling, the surface is placed in a push-type heating furnace for heating at a temperature of 500°C for 3 hours;

[0066] S5. The soaked ingot is hot rolled, with 30 hot rolling passes, a starting rolling temperature of 400-420°C, a convexity of 0-0.2% (target value 0.1%), a final rolling temperature of 305°C, a maximum reduction of 10 mm per pass in the last 3 passes of the plate, and hot rolling to the thickness of the finished hot rolled plate;

[0067] S6. Trim the plate, cut 30mm on one side, and ensure there is no crack on the edge of the plate;

[0068] S7. The hot-rolled aluminum alloy plate is subjected to a solution treatment, the plate thickness is 30 mm, the solution temperature is 545° C., the holding time is 50 min, and the plate is quenched after the solution treatment, and the upper and lower plate surfaces are water-cooled spray quenched, the quenching water high pressure is 0.8-2.0 bar, and the quenching water low pressure is 0.7 bar;

[0069] S8. Complete the straightening of the plate within 6 hours after quenching, strictly control the unevenness of the plate surface after straightening, and control the transverse flatness of the plate within 0.1mm / m;

[0070] S9. After quenching, the plate is stretched within 48 hours using a 40MN stretching machine with a stretching amount of 0.5%. After stretching, the transverse flatness of the plate is ≤0.2mm / m, and the longitudinal flatness is ≤0.2mm / m;

[0071] S10. After the stretching treatment, the aging furnace is aged within 48 hours, the aging temperature is 170°C, the heating rate is 25-30°C / h, and the insulation time is 10-12h;

[0072] S11. Cut the aged boards into finished product specifications and package them.

[0073] The experimental data of Examples 1 to 3 are as follows:

[0074]

[0075] The flatness of the plates produced in Examples 1 to 3 remains substantially unchanged before and after machining, and the dimensional tolerance reaches a relatively high level.

[0076] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A 6061 aluminum alloy super flat plate production process, characterized in that: The following steps are involved: S1. Ingredients, according to mass fraction, the ingredients of 6061 aluminum alloy can material in melting and casting are: Si: 0.4-0.80%, Fe≤0.7%, Cu: 0.15-0.4%, Mn:≤0.15%, Mg: 0.8-1.2%, Zn:≤0.25%, Cr: 0.04-0.35%, Ti≤0.15%, single impurity≤0.05%, total≤0.15%, the balance is Al; S2. After the alloy is prepared according to the mass percentage in step S1, smelting, furnace refining, online degassing, online filtration, the molten aluminum is cast into an aluminum alloy ingot; S3. The ingot is subjected to sawing and milling treatment; S4. After sawing and milling, the surface is placed in a push-type heating furnace for heating at a temperature of 500°C for 3 hours; S5. The soaked ingot is hot rolled, with 30 passes, to the thickness of the finished hot-rolled plate; S6. trimming the plate; S7. The hot-rolled aluminum alloy sheet is subjected to a solution treatment at a solution temperature of 535 to 560° C. for a holding time of 30 to 60 min. After the solution treatment, the sheet is subjected to a quenching treatment, and the upper and lower sheet surfaces are subjected to a water-cooled spray quenching; S8. Complete plate straightening within 6 hours after quenching; S9. Stretching the sheet; S10. After the stretching treatment, the aging furnace is aged within 48 hours, the aging temperature is 165-180°C, the heating rate is 25-30°C / h, and the insulation time is 10-12h; S11. Cut the aged boards into finished product specifications and package them.

2. A 6061 aluminum alloy super flat plate production process according to claim 1, characterized in that: In step S3, the milling surface thickness is 10 mm.

3. The 6061 aluminum alloy super flat plate production process according to claim 1, characterized in that: In the step S5, the starting rolling temperature is 400-420°C, and the finishing rolling temperature is 300-320°C.

4. A 6061 aluminum alloy super flat plate production process according to claim 3, characterized in that: In step S5, the maximum reduction amount of each of the last three rolling passes of the plate is 10 mm.

5. The 6061 aluminum alloy super flat plate production process according to claim 1, characterized in that: In step S6, the cutting width is 30 mm.

6. The 6061 aluminum alloy super flat plate production process according to claim 1, characterized in that: In the step S9, the stretching amount is 0.5-1.0%.

7. A 6061 aluminum alloy super flat plate production process according to claim 6, characterized in that: In the step S9, stretching is performed within 48 hours after quenching.

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