阅读说明：本技术 一种5a12铝合金热轧坯料及其生产方法 (5A12 aluminum alloy hot-rolled blank and production method thereof ) 是由 李国锋 邓艳超 谭盼 李伟坡 刘杰 王军伟 闫帅杰 于 2021-08-13 设计创作，主要内容包括：本发明公开了一种5A12铝合金热轧坯料及其生产方法。该方法以纯铝锭和纯镁锭为原料配料熔炼,所得合金液进行精炼,精炼后静置,将静置后所得合金液进行铸造,得到铝合金铸锭；将所得5A12铝合金铸锭进行三级均匀化处理；然后将铸锭进行铣面,铣面后采用“醋酸水空气联合除杂法”进行处理；处理后铸锭依次进行均质加热、热粗轧和热精轧,最终得到产品厚度为8mm的5A12铝合金热轧坯料。通过本发明能够得到宽度为1200～1700mm的大规格5A12铝合金热轧板材坯料,该产品具有表面质量好、强度高、塑性好、坯料内部无气孔、缩孔等优点；从而改善了现有生产大规格5A12铝合金板材对设备要求高、热轧轧制技术复杂的问题。(The invention discloses a 5A12 aluminum alloy hot-rolled blank and a production method thereof. The method comprises the steps of taking a pure aluminum ingot and a pure magnesium ingot as raw materials, mixing and smelting, refining the obtained alloy liquid, standing after refining, and casting the alloy liquid obtained after standing to obtain an aluminum alloy ingot; carrying out three-stage homogenization treatment on the obtained 5A12 aluminum alloy cast ingot; then, milling the cast ingot, and then processing by adopting an acetic acid water and air combined impurity removal method; and after treatment, carrying out homogeneous heating, hot rough rolling and hot finish rolling on the cast ingot in sequence to finally obtain the 5A12 aluminum alloy hot rolling blank with the thickness of 8 mm. The large-size 5A12 aluminum alloy hot-rolled plate blank with the width of 1200-1700 mm can be obtained through the method, and the product has the advantages of good surface quality, high strength, good plasticity, no air holes or shrinkage holes in the blank and the like; therefore, the problems that the existing large-specification 5A12 aluminum alloy plate production has high equipment requirement and the hot rolling technology is complex are solved.)

1. A hot rolled 5A12 aluminum alloy billet, characterized in that the hot rolled aluminum alloy billet comprises the following alloying elements in mass percent:

less than or equal to 0.30 percent of Si, less than or equal to 0.05 percent of Cu, 8.1 to 9.2 percent of Mg, less than or equal to 0.20 percent of Zn, 0.50 to 0.90 percent of Mn, 0.05 to 0.15 percent of Ti, less than or equal to 0.10 percent of Ni, less than or equal to 0.30 percent of Fe, less than or equal to 0.10 percent of other impurities, and the balance of Al.

2. A production method of a 5a12 aluminum alloy hot rolled blank, characterized in that the production method comprises the steps of:

a. smelting: carrying out ingredient melting on a pure aluminum ingot and a pure magnesium ingot as raw materials, wherein the melting temperature is controlled to be 720-760 ℃ in the melting process, and the melting heat preservation time is 20-30 min; adding intermediate alloys Al-20Si, Al-50Cu, Al-20Mn, Al-5Ni and Al-5Ti-B in the smelting process for batching, wherein the batching temperature is 730-750 ℃, so that the components of the alloy liquid obtained by smelting can meet the alloy element composition of the blank material in claim 1;

b. refining: refining the alloy liquid obtained in the step a, wherein the temperature is controlled to be 720-745 ℃ in the refining process, and the refining time is 30-60 min; standing for 30-40 min after refining;

c. casting: casting the alloy liquid obtained after standing in the step b, and controlling the casting temperature to be 690-725 ℃ in the casting process to obtain an aluminum alloy cast ingot;

d. three-stage homogenization treatment: c, carrying out three-stage homogenization treatment on the cast ingot obtained in the step c by adopting a box type soaking pit furnace;

e. ingot casting pretreatment: d, milling the 5A12 cast ingot after homogenization treatment in the step d, and removing residual impurities on the surface of the cast ingot and preventing the slab from getting damp after the surface is milled by adopting an acetic acid water and air combined impurity removal method;

f. homogenizing and heating: placing the ingot casting obtained by the pretreatment in the step e into a heating furnace for homogenizing and heating;

g. hot rough rolling: rolling the cast ingot treated in the step f by adopting 1+1+1 hot continuous rolling;

h. hot finish rolling: and rolling the blank obtained by the hot rough rolling by adopting three reversible rolling processes to obtain the final blank, namely the 5A12 aluminum alloy hot rolled blank.

3. The production method of the 5A12 aluminum alloy hot rolled blank as claimed in claim 2, wherein the three-stage homogenization treatment in step d comprises the following specific steps:

the first stage is as follows: firstly, setting the furnace gas temperature of a box type soaking pit furnace at 320 ℃, changing the furnace gas temperature to 290 ℃ when the measured metal temperature reaches 275-285 ℃, and preserving heat for 5 hours at the temperature; and a second stage: then, the temperature of furnace gas is set to 380 ℃, when the measured metal temperature reaches 345-355 ℃, the temperature of the furnace gas is changed to 360 ℃, and heat preservation is carried out for 5 hours at the temperature; and a third stage: and finally, keeping the temperature of furnace gas at 470 ℃, keeping the temperature of metal for 12 hours when the temperature reaches 450-460 ℃, and pushing out the slab ingot to naturally cool after the heat preservation time is finished.

4. The production method of a 5A12 aluminum alloy hot rolled blank according to claim 2, wherein: and e, milling the small faces of the two sides of the cast ingot by 20mm respectively and milling the upper large face and the lower large face by 30mm respectively when the cast ingot is milled in the step e by 5A 12.

5. The production method of a 5A12 aluminum alloy hot rolled blank according to claim 2, wherein: and e, after the cast ingot of 5A12 is milled, measuring the side surface curvature of less than or equal to 3mm and the large surface curvature of less than or equal to 2 mm.

6. The production method of the 5A12 aluminum alloy hot rolled blank as claimed in claim 2, wherein the specific process of the 'acetic acid water and air combined impurity removal method' in the step e is as follows:

1) placing the cast ingot after surface milling into a flowing water tank to wash the tiny particles on the surface; 2) placing the rinsed cast ingot in purified water at 85-95 ℃, adding acetic acid with the mass percentage concentration of 1% into the purified water, preheating for 30 minutes, and enabling the surface temperature of the cast ingot to reach 35-45 ℃; 3) then introducing compressed air into the water tank to generate 10000-50000 pieces/cm³And (5) micro bubbles.

7. The method for producing a hot-rolled 5A12 aluminum alloy billet as claimed in claim 2, wherein the homogenizing heating in step f is performed by: and e, placing the ingot obtained by the pretreatment in the step e into a push type heating furnace, setting the temperature of the heating furnace to 520 ℃, keeping the temperature for 2-4 hours under the condition that the temperature of the furnace gas is 470 ℃ when the temperature of the metal reaches 450-460 ℃, and then discharging and rolling.

8. The production method of a 5A12 aluminum alloy hot rolled blank according to claim 2, wherein: in the hot rough rolling process in the step g, the rolling initial rolling temperature is 440-460 ℃, and the final rolling temperature is 380-400 ℃; the hot rough rolling adopts three single rolling reduction of 10mm, 15mm and 20mm, the rolling is carried out for 29 times, and the thickness of the plate obtained after the rough rolling is finished is 35 mm.

9. The method for producing the 5A12 aluminum alloy hot rolled blank according to claim 2, wherein the lubricating medium used in the hot rough rolling process in the step g is emulsion, the concentration of the emulsion is 3.5-4.5%, the temperature of the emulsion is controlled to be 60-65 ℃, the pH value is 7.8-8.4, and the injection pressure for emulsion lubrication is 0.5-0.6 MPa.

10. The method for producing the hot-rolled 5A12 aluminum alloy billet according to claim 2, wherein in the step h, the start rolling temperature is 370-400 ℃ and the finish rolling temperature is 320-340 ℃ in the hot finish rolling process; the reduction amount of each pass is distributed to be 15mm, 8mm and 4mm, and the thickness of the final-rolled plate is 8 mm; the lubricating medium adopted in the hot finish rolling process is emulsion, the concentration of the emulsion is 7-8%, the temperature of the emulsion is controlled to be 60-65 ℃, the pH value is controlled to be 7.8-8.4, and the lubricating injection pressure of the emulsion is 0.5-0.6 Mpa.

The technical field is as follows:

the invention belongs to the technical field of aluminum alloy and preparation thereof, and particularly relates to a 5A12 aluminum alloy hot-rolled blank and a production method thereof.

Secondly, background art:

the 5A12 aluminum alloy is a high-magnesium content 5-series aluminum alloy, belongs to non-heat-treatable alloy, and has the characteristics of high strength, good corrosion resistance, good machinability, good surface quality of anodization, good arc welding performance, good corrosion resistance and the like. The 5A12 alloy is widely used in the fields of ships, plane weldments, subway light rails, missile parts, bulletproof armors and the like. In practical application, the 5A12 alloy is mainly extruded section, the raw material of the extruded section is generally round bar-shaped cast ingot, the diameter is small, the casting is relatively simple, the components are easy to control, and the casting is not easy to crack. The small-diameter round bar cast ingot can be extruded into parts with various shapes by a common extruding machine, but has the defect that the produced parts have small specification and cannot be applied to the production of large-specification parts and welding parts, such as large-specification marine plates, aerospace welding materials, bulletproof armor and other wide rolling materials.

In order to improve the application of the 5A12 alloy to large-size parts, the technology problem which needs to be solved urgently at present can be to produce large-size ingots meeting the requirements.

Thirdly, the invention content:

the technical problem to be solved by the invention is as follows: the invention provides a 5A12 aluminum alloy hot-rolled blank and a production method thereof, aiming at producing a large-size ingot meeting the requirement. The 5A12 alloy wide-width slab ingot hot-rolled blank prepared by the technical scheme of the invention not only can be used as a thick plate production blank, but also can be applied to cold-rolled sheet strips, and the product has the excellent characteristics of high strength, good plasticity, high corrosion resistance, no holes in the interior, slag inclusion, higher plastic elongation and the like. The blank produced by the invention is mainly used for producing cold-rolled sheet strips.

In order to solve the problems, the invention adopts the technical scheme that:

the invention provides a 5A12 aluminum alloy hot-rolled blank, which comprises the following alloy elements in percentage by mass:

less than or equal to 0.30 percent of Si, less than or equal to 0.05 percent of Cu, 8.1 to 9.2 percent of Mg, less than or equal to 0.20 percent of Zn, 0.50 to 0.90 percent of Mn, 0.05 to 0.15 percent of Ti, less than or equal to 0.10 percent of Ni, less than or equal to 0.30 percent of Fe, less than or equal to 0.10 percent of other impurities, and the balance of Al.

Further, there is provided a production method of a 5a12 aluminum alloy hot rolled blank, the production method including the steps of:

a. smelting: carrying out ingredient melting on a pure aluminum ingot and a pure magnesium ingot as raw materials, wherein the melting temperature is controlled to be 720-760 ℃ in the melting process, and the melting heat preservation time is 20-30 min; adding intermediate alloys Al-20Si, Al-50Cu, Al-20Mn, Al-5Ni and Al-5Ti-B in the smelting process for batching, wherein the batching temperature is 730-750 ℃, so that the components of the alloy liquid obtained by smelting meet the alloy element composition of the blank;

b. refining: refining the alloy liquid obtained in the step a, wherein the temperature is controlled to be 720-745 ℃ in the refining process, and the refining time is 30-60 min; standing for 30-40 min after refining;

c. casting: casting the alloy liquid obtained after standing in the step b, and controlling the casting temperature to be 690-725 ℃ in the casting process to obtain an aluminum alloy cast ingot;

d. three-stage homogenization treatment: c, carrying out three-stage homogenization treatment on the cast ingot obtained in the step c by adopting a box type soaking pit furnace (improving the microstructure appearance in the blank through the three-stage homogenization treatment);

e. ingot casting pretreatment: d, milling the 5A12 cast ingot after homogenization treatment in the step d, and removing residual impurities on the surface of the cast ingot and preventing the slab from getting damp after the surface is milled by adopting an acetic acid water and air combined impurity removal method;

f. homogenizing and heating: placing the ingot casting obtained by the pretreatment in the step e into a heating furnace for homogenizing and heating;

g. hot rough rolling: rolling the cast ingot obtained after the treatment of the step f by adopting 1+1+1 hot continuous rolling (a roughing mill, a vertical rolling mill and a finishing mill);

h. hot finish rolling: and rolling the blank obtained by the hot rough rolling by adopting three reversible rolling processes to obtain the final blank, namely the 5A12 aluminum alloy hot rolled blank.

According to the production method of the 5A12 aluminum alloy hot rolled blank, the three-stage homogenization treatment in the step d comprises the following specific steps:

the first stage is as follows: firstly, setting the furnace gas temperature of a box type soaking pit furnace at 320 ℃, changing the furnace gas temperature to 290 ℃ when the measured metal temperature reaches 275-285 ℃, and preserving heat for 5 hours at the temperature; and a second stage: then, the temperature of furnace gas is set to 380 ℃, when the measured metal temperature reaches 345-355 ℃, the temperature of the furnace gas is changed to 360 ℃, and heat preservation is carried out for 5 hours at the temperature; and a third stage: and finally, keeping the temperature of furnace gas at 470 ℃, keeping the temperature of metal for 12 hours when the temperature reaches 450-460 ℃, and pushing out the slab ingot to naturally cool after the heat preservation time is finished.

According to the production method of the 5A12 aluminum alloy hot rolled blank, in the step e, when the surface of the 5A12 cast ingot is milled, the small surfaces on the two sides of the cast ingot are milled by 20mm respectively, and the large surfaces on the upper part and the lower part of the cast ingot are milled by 30mm respectively (chilling crystals and segregation layers are milled completely).

According to the production method of the 5A12 aluminum alloy hot rolled blank, after the 5A12 cast ingot is milled in the step e, the side bending is measured to be less than or equal to 3mm, and the large-area bending is measured to be less than or equal to 2mm (the surface is smooth and has no protrusion).

According to the production method of the 5A12 aluminum alloy hot rolled blank, the specific process of the acetic acid water and air combined impurity removal method in the step e is as follows:

1) placing the cast ingot after surface milling into a flowing water tank to wash the tiny particles on the surface; 2) placing the rinsed cast ingot in purified water at 85-95 ℃, adding acetic acid with the mass percentage concentration of 1% into the purified water, preheating for 30 minutes,the surface temperature of the cast ingot reaches 35-45 ℃ (the surface metal temperature of the cast ingot is measured by a portable thermocouple); 3) then introducing compressed air into the water tank to generate 10000-50000 pieces/cm³Micro bubbles (the purposes of removing impurities and preventing subsequent heating from getting damp) are realized.

According to the above production method of the 5A12 aluminum alloy hot rolled blank, the specific operation of the homogeneous heating in the step f is as follows: and e, placing the ingot obtained by the pretreatment in the step e into a push type heating furnace, setting the temperature of the heating furnace to 520 ℃, keeping the temperature for 2-4 hours under the condition that the temperature of the furnace gas is 470 ℃ when the temperature of the metal reaches 450-460 ℃, and then discharging and rolling.

According to the production method of the 5A12 aluminum alloy hot rolled blank, in the hot rough rolling process in the step g, the rolling initial rolling temperature is 440-460 ℃, and the final rolling temperature is 380-400 ℃; the hot rough rolling adopts three single rolling reduction of 10mm, 15mm and 20mm, the rolling is carried out for 29 times, and the thickness of the plate obtained after the rough rolling is finished is 35 mm.

According to the production method of the 5A12 aluminum alloy hot rolling blank, in the step g, the lubricating medium adopted in the hot rough rolling process is emulsion, the concentration of the emulsion is 3.5-4.5%, the temperature of the emulsion is controlled to be 60-65 ℃, the pH value is 7.8-8.4, and the lubricating injection pressure of the emulsion is 0.5-0.6 MPa.

According to the production method of the 5A12 aluminum alloy hot rolled blank, in the step h of the hot finish rolling process, the initial rolling temperature is 370-400 ℃, and the final rolling temperature is 320-340 ℃; the reduction amount of each pass is distributed to be 15mm, 8mm and 4mm, and the thickness of the final-rolled plate is 8 mm; the lubricating medium adopted in the hot finish rolling process is emulsion, the concentration of the emulsion is 7-8% (7-8% of rolling crude oil and the balance of pure water), the temperature of the emulsion is controlled to be 60-65 ℃, the pH value is controlled to be 7.8-8.4, and the lubricating injection pressure of the emulsion is 0.5-0.6 Mpa.

The invention has the following positive beneficial effects:

1. in the production method, the three-stage homogenization technology adopted for the ingot blank is stage homogenization. The multi-stage homogenization heating is slow, the constant temperature enables the speed curve of the cast ingot to be slow, and the multi-stage heat preservation is matched from low to high, so that the cast ingot cracking caused by the too fast stress release caused by the fast heating is effectively prevented; on the other hand, the homogenization in different stages can effectively eliminate the segregation of ingot components. In addition, stress relief is more complete at different temperature stages. The shape, size and distribution of the second phase of the casting blank tend to be uniform, segregation is reduced, stress distribution along the grain boundary in the plastic deformation process is improved, and the stress distribution is uniform and consistent at each part, so that the technological performance in subsequent processing is improved.

2. The method aims to solve the technical problems that a slab ingot at normal temperature is placed in a high-temperature furnace to generate cold-heat exchange, a lot of small water drops are generated on the surface of the slab under the large cold-heat exchange, the small water drops generate certain corrosion to high-magnesium alloy under the atmosphere of the high-temperature furnace, and the like. According to the technical scheme, an acetic acid-water-air combined impurity removal method is adopted to heat a milled ingot in pure water, the temperature of the pure water is controlled to be 85-95 ℃, 1% acetic acid is added, and a slab ingot is heated for 30 minutes; the temperature of the plate ingot is 35-45 ℃, compressed air is introduced into the water tank to form a large amount of tiny bubbles, and after the plate ingot is cleaned, small water drops do not appear on the surface during subsequent heating.

3. The density of the aluminum is 2.7g/cm³The density of magnesium is 1.7g/cm³The magnesium content of the 5A12 is 8.1-9.2%, the equipment damage is easily caused by the common existing hot rolling process production technology, the reversible rolling is carried out by adopting 29 passes in the technical scheme of the invention, the safety of the production equipment is ensured, the internal crystal grains in the plate blank are uniform, the internal defects such as looseness and the like are avoided, and the plastic deformation capability of the produced product 5A12 aluminum alloy hot rolling blank is improved.

4. The 5A12 aluminum alloy hot-rolled blank prepared by the technical scheme is mainly applied to cold-rolled sheet strips, the tensile strength reaches 390-410 MPa, the elongation is more than or equal to 18%, and the strip convexity is 2.5-4%. The hot rolled blank prepared by the invention has the advantages of good surface quality, high strength, good plasticity, small edge cracking width, no air hole or shrinkage cavity in the blank and the like.

5. The large-size 5A12 aluminum alloy hot-rolled plate blank with the width of 1200-1700 mm can be obtained through the method, and the product has the advantages of good surface quality, high strength, good plasticity, no air holes or shrinkage holes in the blank and the like. Therefore, the problems that the existing large-specification 5A12 aluminum alloy plate production has high equipment requirement and the hot rolling technology is complex are solved.

6. The products prepared by the technical scheme of the invention are detected, and the obtained related performance parameters are detailed in table 1.

TABLE 1 results of testing the properties of the products prepared according to the invention

The fourth embodiment mode is as follows:

the invention is further illustrated by the following examples, which do not limit the scope of the invention.

Example 1:

the 5A12 aluminum alloy hot-rolled blank disclosed by the invention comprises the following alloy elements in percentage by mass:

0.201% of Si, 0.031% of Cu, 8.802% of Mg, 0.101% of Zn, 0.702% of Mn, 0.101% of Ti, 0.060% of Ni, 0.150% of Fe, 0.030% of other impurities and the balance of Al.

Example 2:

the invention discloses a production method of a 5A12 aluminum alloy hot-rolled blank in example 1, which comprises the following detailed steps:

a. smelting: carrying out ingredient melting on a pure aluminum ingot and a pure magnesium ingot as raw materials, wherein the melting temperature is controlled to be 730-750 ℃ in the melting process, and the melting heat preservation time is 25 min; adding intermediate alloys Al-20Si, Al-50Cu, Al-20Mn, Al-5Ni and Al-5Ti-B in the smelting process for batching, wherein the batching temperature is 730-740 ℃, so that the components of the alloy liquid obtained by smelting can meet the alloy element composition of the blank in the embodiment 1;

b. refining: refining the alloy liquid obtained in the step a, wherein the temperature is controlled to be 720-725 ℃ in the refining process, and the refining time is 30 min; standing for 30min after refining;

c. casting: b, casting the alloy liquid obtained after standing in the step b, wherein the casting temperature is controlled to be 695-715 ℃ in the casting process, so as to obtain an aluminum alloy cast ingot;

d. three-stage homogenization treatment: c, carrying out three-stage homogenization treatment on the cast ingot obtained in the step c by adopting a box type soaking pit furnace (improving the microstructure appearance in the blank through the three-stage homogenization treatment);

the specific operation process of the three-section type homogenization treatment comprises the following steps:

the first stage is as follows: firstly, setting the furnace gas temperature of a box type soaking pit furnace at 320 ℃, changing the furnace gas temperature to 290 ℃ when the measured metal temperature reaches 275-285 ℃, and preserving heat for 5 hours at the temperature; and a second stage: then, the temperature of furnace gas is set to 380 ℃, when the measured metal temperature reaches 345-355 ℃, the temperature of the furnace gas is changed to 360 ℃, and heat preservation is carried out for 5 hours at the temperature; and a third stage: finally, keeping the temperature of furnace gas at 470 ℃, keeping the temperature of metal at 450-460 ℃ for 12 hours, and pushing out the slab ingot to naturally cool after the temperature keeping time is finished;

e. ingot casting pretreatment: d, milling the homogenized 5A12 cast ingot in the step d, wherein the facets on the two sides of the cast ingot are milled to be 20mm respectively, and the upper and lower large faces are milled to be 30mm respectively (chilling crystals and segregation layers are milled completely); after the 5A12 cast ingot is milled, measuring the side surface bending degree to be less than or equal to 3mm and the large surface bending degree to be less than or equal to 2mm (the surface has smooth hand feeling and no protrusion); after milling, removing residual impurities on the surface of the cast ingot by adopting an acetic acid water and air combined impurity removal method and preventing the slab from being heated to be damp;

the specific operation process of the acetic acid water-air combined impurity removal method comprises the following steps:

1) placing the cast ingot after surface milling into a flowing water tank to wash the tiny particles on the surface; 2) placing the rinsed cast ingot in purified water at 85-95 ℃, adding acetic acid with the mass percentage concentration of 1% into the purified water, preheating for 30 minutes until the surface temperature of the cast ingot reaches 35-45 ℃ (measuring the surface metal temperature of the cast ingot by using a portable thermocouple); 3) then introducing compressed air into the water tank to generate 10000-50000 pieces/cm³Tiny bubbles (thereby achieving the purposes of removing impurities and preventing subsequent heating from getting damp);

f. homogenizing and heating: placing the ingot casting obtained by the pretreatment in the step e into a heating furnace for homogenizing and heating;

the specific operation of homogenizing heating is as follows: placing the ingot obtained by the pretreatment in the step e into a push type heating furnace, setting the temperature of the heating furnace to 520 ℃, keeping the temperature of the furnace gas at 470 ℃ for 2.5 hours when the temperature of the metal reaches 450-460 ℃, and then discharging and rolling;

g. hot rough rolling: rolling the cast ingot obtained after the treatment of the step f by adopting 1+1+1 hot continuous rolling (a roughing mill, a vertical rolling mill and a finishing mill);

in the hot rough rolling process, the rolling initial rolling temperature is 440-450 ℃, and the final rolling temperature is 385-395 ℃; hot rough rolling adopts three single rolling reduction of 10mm, 15mm and 20mm, rolling is carried out for 29 times, and the thickness of the plate obtained after the rough rolling is finished is 35 mm; the lubricating medium adopted in the hot rough rolling process is emulsion, the concentration of the emulsion is 4.0 percent, the temperature of the emulsion is controlled to be 60-65 ℃, the pH value is 8.0, and the lubricating injection pressure of the emulsion is set to be 0.5 Mpa;

the hot rough rolling pass distribution is as follows:

h. hot finish rolling: rolling the blank obtained by the hot rough rolling by adopting three reversible rolling processes to obtain a final blank, namely a 5A12 aluminum alloy hot rolling blank;

in the hot finish rolling process, the initial rolling temperature is 370-390 ℃, and the final rolling temperature is 320-330 ℃; the reduction amount of each pass is distributed to be 15mm, 8mm and 4mm, and the thickness of the final-rolled plate is 8 mm; wherein the concentration of the emulsion is controlled to be 7-8% (7-8% of rolling crude oil and the balance of pure water), the temperature of the emulsion is controlled to be 60-65 ℃, the pH value is controlled to be 7.8-8.4, and the lubricating injection pressure of the emulsion is set to be 0.55 MPa.

The data of the relevant property measurements of the product prepared in this example are detailed in table 2.

TABLE 2 results of testing the properties of the products prepared according to the invention

Example 3:

the 5A12 aluminum alloy hot-rolled blank disclosed by the invention comprises the following alloy elements in percentage by mass:

0.221% of Si, 0.022% of Cu, 8.668% of Mg, 0.113% of Zn, 0.689% of Mn, 0.088% of Ti, 0.051% of Ni, 0.110% of Fe, 0.030% of other impurities and the balance of Al.

Example 4:

the invention discloses a production method of a 5A12 aluminum alloy hot-rolled blank in embodiment 3, which comprises the following detailed steps:

a. smelting: carrying out ingredient melting on a pure aluminum ingot and a pure magnesium ingot serving as raw materials, wherein the melting temperature is controlled to be 735-760 ℃ in the melting process, and the melting heat preservation time is 20 min; adding intermediate alloys Al-20Si, Al-50Cu, Al-20Mn, Al-5Ni and Al-5Ti-B in the smelting process for proportioning, wherein the proportioning temperature is 735-750 ℃, so that the components of the alloy liquid obtained by smelting can meet the alloy element composition of the blank in the embodiment 3;

b. refining: refining the alloy liquid obtained in the step a, wherein the temperature is controlled to be 730-745 ℃ in the refining process, and the refining time is 40 min; standing for 35min after refining;

c. casting: b, casting the alloy liquid obtained after standing in the step b, wherein the casting temperature is controlled to be 700-720 ℃ in the casting process, so as to obtain an aluminum alloy cast ingot;

d. three-stage homogenization treatment: c, carrying out three-stage homogenization treatment on the cast ingot obtained in the step c by adopting a box type soaking pit furnace (improving the microstructure appearance in the blank through the three-stage homogenization treatment);

the specific operation process of the three-section type homogenization treatment comprises the following steps:

the first stage is as follows: firstly, setting the furnace gas temperature of a box type soaking pit furnace at 320 ℃, changing the furnace gas temperature to 290 ℃ when the measured metal temperature reaches 275-285 ℃, and preserving heat for 5 hours at the temperature; and a second stage: then, the temperature of furnace gas is set to 380 ℃, when the measured metal temperature reaches 345-355 ℃, the temperature of the furnace gas is changed to 360 ℃, and heat preservation is carried out for 5 hours at the temperature; and a third stage: finally, keeping the temperature of furnace gas at 470 ℃, keeping the temperature of metal at 450-460 ℃ for 12 hours, and pushing out the slab ingot to naturally cool after the temperature keeping time is finished;

e. ingot casting pretreatment: d, milling the homogenized 5A12 cast ingot in the step d, wherein the facets on the two sides of the cast ingot are milled to be 20mm respectively, and the upper and lower large faces are milled to be 30mm respectively (chilling crystals and segregation layers are milled completely); after the 5A12 cast ingot is milled, measuring the side surface bending degree to be less than or equal to 3mm and the large surface bending degree to be less than or equal to 2mm (the surface has smooth hand feeling and no protrusion); after milling, removing residual impurities on the surface of the cast ingot by adopting an acetic acid water and air combined impurity removal method and preventing the slab from being heated to be damp;

the specific operation process of the acetic acid water-air combined impurity removal method comprises the following steps:

1) placing the cast ingot after surface milling into a flowing water tank to wash the tiny particles on the surface; 2) placing the rinsed cast ingot in purified water at 85-95 ℃, adding acetic acid with the mass percentage concentration of 1% into the purified water, preheating for 30 minutes until the surface temperature of the cast ingot reaches 35-45 ℃ (measuring the surface metal temperature of the cast ingot by using a portable thermocouple); 3) then introducing compressed air into the water tank to generate 10000-50000 pieces/cm³Micro bubble (for removing impurity and preventing subsequent heating 'moisture regain')

f. Homogenizing and heating: placing the ingot casting obtained by the pretreatment in the step e into a heating furnace for homogenizing and heating;

the specific operation of homogenizing heating is as follows: placing the ingot obtained by the pretreatment in the step e into a push type heating furnace, keeping the temperature of the heating furnace at 520 ℃, keeping the temperature of the furnace gas at 470 ℃ for 4 hours when the temperature of the metal reaches 450-460 ℃, and then discharging and rolling;

g. hot rough rolling: rolling the cast ingot obtained after the treatment of the step f by adopting 1+1+1 hot continuous rolling (a roughing mill, a vertical rolling mill and a finishing mill);

in the hot rough rolling process, the rolling initial rolling temperature is 440-450 ℃, and the final rolling temperature is 385-395 ℃; hot rough rolling adopts three single rolling reduction of 10mm, 15mm and 20mm, rolling is carried out for 29 times, and the thickness of the plate obtained after the rough rolling is finished is 35 mm; the lubricating medium adopted in the hot rough rolling process is emulsion, the concentration of the emulsion is set to be 4.0 percent, the temperature of the emulsion is controlled to be 60-65 ℃, the pH value is 8.0, and the lubricating injection pressure of the emulsion is set to be 0.5 Mpa;

the hot rough rolling pass distribution is as follows:

h. hot finish rolling: rolling the blank obtained by the hot rough rolling by adopting three reversible rolling processes to obtain a final blank, namely a 5A12 aluminum alloy hot rolling blank;

in the hot finish rolling process, the initial rolling temperature is 370-390 ℃, and the final rolling temperature is 320-330 ℃; the reduction amount of each pass is distributed to be 15mm, 8mm and 4mm, and the thickness of the final-rolled plate is 8 mm; wherein the concentration of the emulsion is controlled to be 7-8% (7-8% of rolling crude oil and the balance of pure water), the temperature of the emulsion is controlled to be 60-65 ℃, the pH value is controlled to be 7.8-8.4, and the lubricating injection pressure of the emulsion is set to be 0.55 MPa.

Through a tensile test, the uniaxial tensile curve of the 5A12 aluminum alloy plate blank of the product of the invention is obtained, and the mechanical properties of the plate blank, such as tensile strength, yield strength, elongation and the like, are further obtained.

The data of the relevant property measurements of the product prepared in this example are detailed in table 3.

TABLE 3 Performance test results of the products prepared in this example