Al-Mg-Sr alloy material, Al-Mg-Sr alloy plate and preparation method of Al-Mg-Sr alloy plate

Abstract

The invention discloses an Al-Mg-Sr alloy material, an Al-Mg-Sr alloy plate and a preparation method of the Al-Mg-Sr alloy plate. The Al-Mg-Sr alloy material comprises the following components in percentage by weight: 0.1 to 0.5 percent of strontium, 4.0 to 4.9 percent of magnesium, 0.4 to 1.0 percent of manganese, 0.05 to 0.25 percent of chromium, 0.01 to 0.03 percent of titanium, inevitable impurities and the balance of aluminum, and the total content of the inevitable impurities is less than or equal to 0.05 percent by weight. The strontium element is added into the aluminum-magnesium alloy, the mechanical property of the prepared novel Al-Mg-Sr alloy is further improved by using the modification principle and the grain refinement effect of strontium, the corrosion resistance of the novel Al-Mg-Sr alloy is remarkably enhanced, and the aluminum alloy can be promoted to be widely applied to ships and warships.

Description

Technical Field

[0001] The invention belongs to the technical field of alloy materials, and in particular relates to an Al-Mg-Sr alloy material, an Al-Mg-Sr alloy plate and a preparation method thereof. Background Art

[0002] Aluminum-magnesium alloy is an aluminum alloy with Mg as the main added element. Aluminum-magnesium alloy has high specific strength, good corrosion resistance and weldability, and is widely used in facilities in seawater (such as hulls), armor, rail cars and storage tanks. An important use of aluminum-magnesium alloy is the construction of hulls. Using aluminum-magnesium alloy instead of steel can reduce weight by 15-20%, greatly reduce fuel consumption and increase the volume and carrying capacity of the hull. When the magnesium content in aluminum-magnesium alloy is less than 3%, aluminum-magnesium alloy has good resistance to intergranular corrosion. Most of the magnesium atoms are dissolved in the matrix, and there is little β phase precipitation at the grain boundary. However, when the magnesium content is higher than 3%, the intergranular corrosion sensitivity of aluminum-magnesium alloy is greatly increased, mainly because the grain boundary β phase in aluminum-magnesium alloy has a lower corrosion potential, which is easy to form local micro-batteries and is preferentially dissolved in a corrosive environment, thereby causing intergranular corrosion. Summary of the invention

[0003] The main purpose of the present invention is to provide an Al-Mg-Sr alloy material, an Al-Mg-Sr alloy plate and a preparation method thereof, so as to overcome the deficiencies existing in the prior art.

[0004] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0005] The present invention provides an Al-Mg-Sr alloy material, comprising 0.1-0.5wt.% of strontium, 4.0-4.9wt.% of magnesium, 0.4-1.0wt.% of manganese, 0.05-0.25wt.% of chromium, 0.01-0.03wt.% of titanium and inevitable impurities, with the balance being aluminum, wherein the total content of the inevitable impurities is ≤0.05wt.%.

[0006] The present invention also provides an Al-Mg-Sr alloy plate, which is made of the aforementioned Al-Mg-Sr alloy material.

[0007] The present invention also provides a method for preparing an Al-Mg-Sr alloy plate, comprising:

[0008] Prepare raw materials according to the composition of the aforementioned Al-Mg-Sr alloy material, and smelt and cast them into Al-Mg-Sr alloy ingots;

[0009] The Al-Mg-Sr alloy ingot is heated, homogenized, and hot-rolled to form a hot-rolled plate;

[0010] The hot-rolled sheet is cold-rolled to form a cold-rolled sheet;

[0011] The cold-rolled sheet is annealed and then naturally cooled to room temperature to obtain the Al-Mg-Sr alloy sheet.

[0012] Furthermore, the method for preparing the Al-Mg-Sr alloy plate comprises: heating the Al-Mg-Sr alloy ingot to 480-530° C. and homogenizing for 7-9 hours, and then performing the hot rolling.

[0013] Furthermore, the hot rolling process conditions include: a roll temperature of 150-200°C, an ingot thickness of 45-55mm, a pressing amount of 5-8mm per pass, and a final rolling temperature controlled at 300-400°C.

[0014] Furthermore, the preparation method of the Al-Mg-Sr alloy plate also includes: during the hot rolling process, when the final rolling is completed and the rolled plate temperature is lower than 350°C, tempering and keeping the rolled plate at 450-500°C for 30-60 minutes, and finally controlling the thickness of the rolled plate to be 8-12mm, and then quickly water cooling to room temperature to form the hot rolled plate.

[0015] Furthermore, the preparation method of the Al-Mg-Sr alloy plate also includes: after completing the hot rolling, keeping the hot-rolled plate at 300°C to 350°C for 4-6 hours, then taking it out and naturally cooling it to 100-200°C, and then performing the cold rolling.

[0016] The present invention also provides an Al-Mg-Sr alloy plate, which is made by the above method.

[0017] The precipitation phase of aluminum-magnesium alloy is white fractured ternary phase Al6(Mn Cr Fe), Al6(Mn Fe) and Al6Mn phase, and a small amount of granular θ-Al 45 (Mn Cr)7 phase, β-Al3Mg2 phase at the grain boundary and Al6(Mn Cr Fe) and θ-Al 45 (Mn Cr)7 phase precipitates on the surface, and the Fe content of the iron-rich phase in the precipitated phase is relatively high.

[0018] The present invention adds Sr element to the aluminum-magnesium alloy to convert the precipitate phase into Al4Sr phase, Al6Mn and Al6(Mn Cr) phase, and simultaneously generates a high-magnesium ternary phase τ-Al 38 Mg 58Sr4 phase consumes Mg atoms, inhibiting the precipitation of β-Al3Mg2 phase with a potential lower than the Al matrix, and at the same time inhibiting the precipitation of hard and brittle phases Al6(Mn Cr Fe) phase and Al6(Mn Fe) phase with a potential higher than the Al matrix. The potential unevenness between the precipitated phases is reduced, and the alloy forming properties and corrosion resistance are enhanced.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The present invention adds strontium to aluminum-magnesium alloy to prepare a new Al-Mg-Sr alloy. Through the modification principle and grain refinement of strontium, the grain size of the cast alloy is reduced, the second phase enrichment and segregation degree are reduced, the precipitation of the iron-rich phase is suppressed, and the forming performance of the alloy is improved. The mechanical properties of the alloy are further improved, and the corrosion resistance of the alloy is significantly enhanced, providing a new alloy for the wide application of aluminum alloys in ships.

[0021] (2) The method for preparing Al-Mg-Sr alloy plate of the present invention combines hot rolling and cold rolling to increase the deformation of the alloy, increase the dislocation density, enhance the work hardening effect of the alloy, and effectively improve the mechanical properties of the alloy. DETAILED DESCRIPTION

[0022] In view of the deficiencies in the prior art, the inventors of this case, after long-term research and extensive practice, have proposed an Al-Mg-Sr alloy material, an Al-Mg-Sr alloy plate and a preparation method thereof, by adding Sr element to the aluminum-magnesium alloy to transform the precipitate phase into Al4Sr phase, Al6Mn and Al6(Mn Cr) phase, and at the same time generate a high-magnesium ternary phase τ-Al 38 Mg 58 The Sr4 phase consumes Mg atoms, inhibits the precipitation of the β-Al3Mg2 phase whose potential is lower than that of the Al matrix, and inhibits the precipitation of the hard and brittle phases Al6(Mn Cr Fe) phase and Al6(Mn Fe) phase whose potential is higher than that of the Al matrix, so that the potential heterogeneity between the precipitated phases is reduced, and the alloy forming performance and corrosion resistance are enhanced. The technical scheme, its implementation process and principle are further explained as follows.

[0023] One aspect of an embodiment of the present invention provides an Al-Mg-Sr alloy material, comprising 0.1-0.5wt.% strontium, 4.0-4.9wt.% magnesium, 0.4-1.0wt.% manganese, 0.05-0.25wt.% chromium, 0.01-0.03wt.% titanium and inevitable impurities, with the balance being aluminum, wherein the total content of the inevitable impurities is ≤0.05wt.%.

[0024] Another aspect of the embodiments of the present invention provides an Al-Mg-Sr alloy plate, wherein the Al-Mg-Sr alloy plate is made of the aforementioned Al-Mg-Sr alloy material.

[0025] Another aspect of the embodiments of the present invention further provides a method for preparing an Al-Mg-Sr alloy plate, comprising:

[0026] Prepare raw materials according to the composition of the aforementioned Al-Mg-Sr alloy material, and smelt and cast them into Al-Mg-Sr alloy ingots;

[0027] The Al-Mg-Sr alloy ingot is heated, homogenized, and hot-rolled to form a hot-rolled plate;

[0028] The hot-rolled sheet is cold-rolled to form a cold-rolled sheet;

[0029] The cold-rolled sheet is annealed and then naturally cooled to room temperature to obtain the Al-Mg-Sr alloy sheet.

[0030] In some preferred embodiments, the method for preparing the Al-Mg-Sr alloy plate comprises: smelting the raw materials of the Al-Mg-Sr alloy material, forming an alloy plate ingot by negative pressure casting, and removing the skin of the plate ingot to obtain the Al-Mg-Sr alloy ingot.

[0031] In some preferred embodiments, the method for preparing the Al-Mg-Sr alloy plate comprises: heating the Al-Mg-Sr alloy ingot to 480-530° C. and homogenizing for 7-9 hours, and then performing the hot rolling.

[0032] In some more preferred embodiments, the method for preparing the Al-Mg-Sr alloy plate comprises: heating the Al-Mg-Sr alloy ingot to 480-530° C. and homogenizing for 8 hours, and then performing the hot rolling.

[0033] In some preferred embodiments, the hot rolling process conditions include: a roll temperature of 150-200°C, an ingot thickness of 45-55 mm, a pressing amount of 5-8 mm per pass, and a final rolling temperature controlled at 300-400°C.

[0034] In some more preferred embodiments, the hot rolling process conditions include: roll temperature of 150-200°C, ingot thickness of 45-55mm, pressing amount of each pass of 5-8mm, and final rolling temperature controlled at 350°C.

[0035] In some preferred embodiments, the preparation method of the Al-Mg-Sr alloy plate further includes: during the hot rolling process, when the final rolling is completed and the rolled plate temperature is lower than 350°C, tempering and keeping the rolled plate at 450-500°C for 30-60 minutes, and finally controlling the thickness of the rolled plate to be 8-12mm, and then quickly water cooling to room temperature to form the hot rolled plate.

[0036] In some more preferred embodiments, the preparation method of the Al-Mg-Sr alloy plate further includes: during the hot rolling process, when the final rolling is completed and the rolled plate temperature is lower than 350°C, tempering and keeping the rolled plate at 480°C for 30-60 minutes, and finally controlling the thickness of the rolled plate to be 10 mm, and then quickly water cooling to room temperature to form the hot rolled plate.

[0037] In some preferred embodiments, the method for preparing the Al-Mg-Sr alloy plate further includes: after completing the hot rolling, keeping the hot-rolled plate at 300°C to 350°C for 4-6 hours, then taking it out and naturally cooling it to 100-200°C, and then performing the cold rolling.

[0038] In some more preferred embodiments, the preparation method of the Al-Mg-Sr alloy plate further includes: after completing the hot rolling, keeping the hot-rolled plate at 300°C to 350°C for 4-6 hours, then taking it out and naturally cooling it to 150°C, and then performing the cold rolling.

[0039] In some preferred embodiments, the process conditions of the cold rolling treatment include: the cold rolling temperature is controlled at 100-150°C, the roller temperature is 50°C-100°C, the pressing amount is 3-5mm, the final rolling temperature is controlled at 40-60°C, and an Al-Mg-Sr alloy plate with a thickness of 4-6mm is obtained, which is then cooled to room temperature.

[0040] In some more preferred embodiments, the process conditions of the cold rolling treatment include: the cold rolling temperature is controlled at 100-150°C, the roller temperature is 50°C-100°C, the pressing amount is 3-5mm, the final rolling temperature is controlled at 50°C, and an Al-Mg-Sr alloy plate with a thickness of 5mm is obtained, which is then cooled to room temperature.

[0041] In some preferred embodiments, the process conditions of the annealing treatment include: annealing temperature of 220° C. to 250° C., and insulation time of 0.8-1.2 h.

[0042] In some more preferred embodiments, the process conditions of the annealing treatment include: annealing temperature is 220° C. to 250° C., and the temperature is kept for 1 hour.

[0043] The embodiment of the present invention further provides an Al-Mg-Sr alloy plate, which is made by the above method.

[0044] The technical scheme of the present invention is further described in detail below in conjunction with several preferred embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. The test methods in the following embodiments that do not specify specific conditions are usually based on conventional conditions.

[0045] Example 1

[0046] The composition of an Al-Mg-Sr alloy material provided in this embodiment is as follows: 0.1wt.%, strontium, 4.0wt.%, magnesium, 0.72wt.%, manganese, 0.05wt.%, chromium, 0.01wt.%, titanium, and inevitable impurities (total content ≤0.05%), and the balance is aluminum.

[0047] This embodiment also provides an Al-Mg-Sr alloy plate, and the preparation method thereof comprises the following steps:

[0048] Firstly, raw materials are prepared according to the composition of the Al-Mg-Sr alloy material, and the raw materials are smelted and poured through negative pressure casting to obtain alloy plate ingots, and the plate ingots are skinned to obtain Al-Mg-Sr alloy ingots.

[0049] Thereafter, the Al-Mg-Sr alloy ingot is heated to 480°C, homogenized for 8 hours, and then hot rolled, the roll temperature is 150°C, the ingot thickness is 45mm, the pressing amount per pass is 5mm, the final rolling temperature is controlled at 350°C, and when the plate temperature is lower than 350°C, it is returned to the furnace and kept at 480°C for 30min, and the final hot-rolled plate thickness is controlled to be 10mm, and then quickly water-cooled to room temperature. The hot-rolled plate is kept in a furnace at 300°C for 4 hours, then taken out, naturally cooled to 150°C, and cold rolling is started. The cold rolling temperature is controlled at 100°C, the roll temperature is 50°C, the pressing amount is 3mm, and the final rolling temperature is controlled at 50°C to obtain an Al-Mg-Sr alloy plate with a thickness of 5mm, which is then cooled to room temperature and annealed at 250°C for 1 hour. The tensile strength, yield strength and NAMLT values ​​of the corrosion-resistant high-strength Al-Mg-Sr alloy plate are shown in Table 1.

[0050] Example 2

[0051] The composition of an Al-Mg-Sr alloy material provided in this embodiment is as follows: 0.21wt.% strontium, 4.68wt.% magnesium, 0.45wt.% manganese, 0.1wt.% chromium, 0.015wt.% titanium and inevitable impurities (total content ≤0.05%), and the balance is aluminum.

[0052] Firstly, raw materials are prepared according to the composition of the Al-Mg-Sr alloy material, and the raw materials are smelted and poured through negative pressure casting to obtain alloy plate ingots, and the plate ingots are skinned to obtain Al-Mg-Sr alloy ingots.

[0053] Thereafter, the Al-Mg-Sr alloy ingot is heated to 530°C, homogenized for 8 hours, and then hot rolled, the roll temperature is 200°C, the ingot thickness is 55mm, the pressing amount per pass is 8mm, the final rolling temperature is controlled at 350°C, and when the plate temperature is lower than 350°C, it is returned to the furnace and kept at 480°C for 30-60min, and the final hot-rolled plate thickness is controlled to be 10mm, and then quickly water-cooled to room temperature. The hot-rolled plate is kept in a furnace at 350°C for 6 hours, then taken out, naturally cooled to 150°C, and cold rolling is started. The cold rolling temperature is controlled at 150°C, the roll temperature is 100°C, the pressing amount is 5mm, and the final rolling temperature is controlled at 50°C to obtain an Al-Mg-Sr alloy plate with a thickness of 5mm, which is then cooled to room temperature and annealed at 220°C for 1 hour. The tensile strength, yield strength and NAMLT values ​​of the corrosion-resistant high-strength Al-Mg-Sr alloy plate are shown in Table 1.

[0054] Example 3

[0055] The composition of an Al-Mg-Sr alloy material provided in this embodiment is as follows: 0.35wt.% strontium, 4.68wt.% magnesium, 0.73wt.% manganese, 0.15wt.% chromium, 0.015wt.% titanium and inevitable impurities (total content ≤0.05%), and the balance is aluminum.

[0056] Firstly, raw materials are prepared according to the composition of the Al-Mg-Sr alloy material, and the raw materials are smelted and poured through negative pressure casting to obtain alloy plate ingots, and the plate ingots are skinned to obtain Al-Mg-Sr alloy ingots.

[0057] Thereafter, the Al-Mg-Sr alloy ingot is heated to 500°C, homogenized for 8 hours, and then hot rolled, the roll temperature is 180°C, the ingot thickness is 50mm, the pressing amount per pass is 6mm, the final rolling temperature is controlled at 350°C, and when the plate temperature is lower than 350°C, it is returned to the furnace and kept at 480°C for 50min, and the final hot-rolled plate thickness is controlled to be 10mm, and then quickly water-cooled to room temperature. The hot-rolled plate is kept in a furnace at 330°C for 5 hours, then taken out, naturally cooled to 150°C, and cold rolling is started. The cold rolling temperature is controlled at 120°C, the roll temperature is 80°C, the pressing amount is 5mm, and the final rolling temperature is controlled at 50°C to obtain an Al-Mg-Sr alloy plate with a thickness of 5mm, which is then cooled to room temperature. The tensile strength, yield strength and NAMLT values ​​of the corrosion-resistant high-strength Al-Mg-Sr alloy plate are shown in Table 1.

[0058] Example 4

[0059] The composition of an Al-Mg-Sr alloy material provided in this embodiment is as follows: 0.50wt.% strontium, 4.9wt.% magnesium, 0.96wt.% manganese, 0.21wt.% chromium, 0.028wt.% titanium and inevitable impurities (total content ≤0.05%), and the balance is aluminum.

[0060] Firstly, raw materials are prepared according to the composition of the Al-Mg-Sr alloy material, and the raw materials are smelted and poured through negative pressure casting to obtain alloy plate ingots, and the plate ingots are skinned to obtain Al-Mg-Sr alloy ingots.

[0061] Thereafter, the Al-Mg-Sr alloy ingot is heated to 510°C, homogenized for 8 hours, and then hot rolled, the roll temperature is 160°C, the ingot thickness is 50mm, the pressing amount per pass is 5mm, the final rolling temperature is controlled at 350°C, and when the plate temperature is lower than 350°C, it is returned to the furnace and kept at 480°C for 40min, and the final hot-rolled plate thickness is controlled to be 10mm, and then quickly water-cooled to room temperature. The hot-rolled plate is kept in a furnace at 320°C for 6 hours, then taken out, naturally cooled to 150°C, and cold rolling is started. The cold rolling temperature is controlled at 120°C, the roll temperature is 60°C, the pressing amount is 4mm, and the final rolling temperature is controlled at 50°C to obtain an Al-Mg-Sr alloy plate with a thickness of 5mm, which is then cooled to room temperature and annealed at 240°C for 1 hour. The tensile strength, yield strength and NAMLT values ​​of the corrosion-resistant high-strength Al-Mg-Sr alloy plate are shown in Table 1.

[0062] Comparative Example

[0063] The composition of an Al-Mg alloy material provided in this comparative example is as follows: 4.88 wt.%, magnesium, 0.82 wt.%, manganese, 0.25 wt.%, chromium, 0.015 wt.%, titanium, and the balance is aluminum.

[0064] This comparative example also provides an Al-Mg alloy plate, the preparation method of which comprises the following steps:

[0065] Firstly, raw materials are prepared according to the composition of the Al-Mg alloy material, and the raw materials are smelted and then cast by negative pressure casting to obtain alloy plate ingots, thereby obtaining Al-Mg alloy ingots.

[0066] Thereafter, the Al-Mg alloy ingot is heated to 510°C, homogenized for 8 hours, and then hot rolled, the roll temperature is 160°C, the ingot thickness is 50mm, the pressing amount per pass is 5mm, the final rolling temperature is controlled at 350°C, and when the plate temperature is lower than 350°C, it is returned to the furnace and kept at 480°C for 40min, and the final hot-rolled plate thickness is controlled to be 10mm, and then quickly water-cooled to room temperature. The hot-rolled plate is kept in a furnace at 320°C for 5 hours, then taken out, naturally cooled to 150°C, and cold rolling is started. The cold rolling temperature is controlled at 120°C, the roll temperature is 60°C, the pressing amount is 4mm, and the final rolling temperature is controlled at 50°C to obtain an Al-Mg-Sr alloy plate with a thickness of 5mm, which is then cooled to room temperature and annealed at 240°C for 1 hour. The tensile strength, yield strength and NAMLT values ​​of the corrosion-resistant high-strength Al-Mg-Sr alloy plate are shown in Table 1.

[0067] Table 1 Raw material quality, mechanical properties and NAMLT value

[0068]

[0069]

[0070] As shown in Table 1, the tensile strength and yield strength of the Al-Mg alloy increased significantly with the addition of Sr elements. As the Sr content increased, the mechanical properties of the alloy were enhanced. The intergranular corrosion mass loss of the alloy decreased with the addition of Sr elements, indicating that the Sr element increased the intergranular corrosion resistance. When the Sr content increased, the mass loss of the alloy increased, indicating that the intergranular corrosion resistance of the alloy was weakened and the corrosion resistance decreased.

[0071] In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments with other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.

[0072] Although the present invention has been described with reference to illustrative embodiments, it will be appreciated by those skilled in the art that various other changes, omissions and / or additions may be made without departing from the spirit and scope of the present invention and that the elements of the embodiments may be replaced by substantial equivalents. In addition, many modifications may be made without departing from the scope of the present invention to adapt specific circumstances or materials to the teachings of the present invention. Therefore, it is not intended herein to limit the present invention to the disclosed specific embodiments for performing the present invention, but it is intended that the present invention will include all embodiments within the scope of the appended claims. In addition, unless specifically stated, any use of the terms first, second, etc. does not indicate any order or importance, but rather uses the terms first, second, etc. to distinguish one element from another.

Claims

1. An Al-Mg-Sr alloy material, characterized in that: Contains 0.1-0.5wt.% of strontium, 4.0-4.9wt.% of magnesium, 0.4-1.0wt.% of manganese, 0.05-0.25wt.% of chromium, 0.01-0.03wt.% of titanium and inevitable impurities, and the balance is aluminum, wherein the total content of the inevitable impurities is ≤0.05wt.%.

2. An Al-Mg-Sr alloy plate, characterized in that: The Al—Mg—Sr alloy plate is made of the Al—Mg—Sr alloy material according to claim 1 .

3. A method for preparing an Al-Mg-Sr alloy plate, characterized in that: include: Prepare raw materials according to the composition of the Al-Mg-Sr alloy material according to claim 1, and smelt and cast them into Al-Mg-Sr alloy ingots; The Al-Mg-Sr alloy ingot is heated, homogenized, and hot-rolled to form a hot-rolled plate; The hot-rolled sheet is cold-rolled to form a cold-rolled sheet; The cold-rolled sheet is annealed and then naturally cooled to room temperature to obtain the Al-Mg-Sr alloy sheet.

4. The method for preparing the Al-Mg-Sr alloy plate according to claim 3, characterized in that: include: The raw materials of the Al-Mg-Sr alloy material are smelted and then poured through negative pressure casting to form an alloy plate ingot, and the plate ingot is skinned to obtain the Al-Mg-Sr alloy ingot.

5. The method for preparing the Al-Mg-Sr alloy plate according to claim 3, characterized in that: include: The Al-Mg-Sr alloy ingot is heated to 480-530° C. and homogenized for 7-9 hours, and then hot rolled.

6. The method for preparing the Al-Mg-Sr alloy plate according to claim 3, characterized in that: The hot rolling process conditions include: a roll temperature of 150-200°C, an ingot thickness of 45-55mm, a pressing amount of 5-8mm per pass, and a final rolling temperature controlled at 300-400°C.

7. The method for preparing the Al-Mg-Sr alloy plate according to claim 3, characterized in that: Also includes: During the hot rolling process, after the final rolling is completed and the temperature of the rolled plate is lower than 350°C, the rolled plate is tempered and kept at 450-500°C for 30-60min, and the thickness of the rolled plate is finally controlled to be 8-12mm, and then quickly water-cooled to room temperature to form the hot rolled plate.

8. The method for preparing the Al-Mg-Sr alloy plate according to claim 3, characterized in that: Also includes: After the hot rolling is completed, the hot rolled plate is kept at 300°C to 350°C for 4-6 hours, then taken out and naturally cooled to 100-200°C, and then the cold rolling is performed.

9. The method for preparing an Al-Mg-Sr alloy plate according to claim 3, characterized in that: The process conditions of the cold rolling treatment include: the cold rolling temperature is controlled at 100-150°C, the roller temperature is 50-100°C, the pressing amount is 3-5mm, the final rolling temperature is controlled at 40-60°C, and an Al-Mg-Sr alloy plate with a thickness of 4-6mm is obtained, and then cooled to room temperature; And / or, the process conditions of the annealing treatment include: annealing temperature is 220° C. to 250° C., and insulation time is 0.8-1.2 h.

10. An Al-Mg-Sr alloy plate, characterized in that: It is prepared by the method described in any one of claims 3-9.

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