High-strength corrosion-resistant aluminum profile for vehicle and ship box body and preparation process of high-strength corrosion-resistant aluminum profile

Abstract

The invention relates to the technical field of aluminum alloy preparation, and discloses a high-strength corrosion-resistant aluminum profile for vehicle and ship box bodies and a preparation process of the high-strength corrosion-resistant aluminum profile for the vehicle and ship box bodies. 0.6%-0.9% of Mn; 0.4%-0.7% of Si; 0.08% to 0.15% of Zr; 0.05% to 0.12% of La; 0.06% to 0.10% of Ti; 0.03% to 0.08% of Ce; 0.003% to 0.005% of B; 0.01% to 0.04% of Y; 0.15% to 0.25% of Cr; 0.2%-0.4% of Cu; 0.05% to 0.10% of V; less than 0.15% of impurity components; and the balance of Al. According to the scheme, the technological conditions are adjusted by combining the component characteristics, and the high-strength and corrosion-resistant aluminum profile for the vehicle and ship box is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloy preparation, and specifically to an aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes and its preparation process. Background Art

[0002] Although aluminum profiles are widely used in vehicle and ship boxes due to their lightweight characteristics, compared with steel, aluminum profiles are slightly inferior in terms of strength, and in a marine environment, their corrosion resistance still needs to be further improved. The existing technology mainly starts from the process perspective for improvement, or the corrosion resistance of aluminum profiles is largely achieved through coatings. And it is found that even if the composition can obtain high-strength and corrosion-resistant aluminum profiles, during the processing and preparation process, the burning loss rate of Mg will cause performance deviation. Summary of the Invention

[0003] For this reason, the present invention provides an aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes and its preparation process to solve the above problems in the existing technology.

[0004] In order to achieve the above object, the present invention provides the following technical solutions: According to the first aspect of the present invention, an aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes, by mass percentage, includes the following components: Mg 4.2% - 4.8%; Mn 0.6% - 0.9%; Si 0.4% - 0.7%; Zr 0.08% - 0.15%; La 0.05% - 0.12%; Ti 0.06% - 0.10%; Ce 0.03% - 0.08%; B 0.003% - 0.005%; Y 0.01% - 0.04%; Cr 0.15% - 0.25%; Cu 0.2% - 0.4%; V 0.05% - 0.10%; Impurity components < 0.15%; The balance is Al.

[0005] The purpose of this solution is to improve the strength and corrosion resistance of the aluminum profile, so the component design has the following characteristics: In terms of strength improvement: Mg and Si can form Mg2Si strengthening phases during the preparation process. Mg, Al, and Cu form various alloy phases in the matrix, such as Al3Mg2 phase and Al2CuMg phase, and these alloy phases can strengthen the structure; Cu and Mn can also improve the strength through solid solution strengthening, and Mn can further refine the grains to enhance the strength; Cr and V can form dispersed particles to inhibit the grain growth during the recrystallization of aluminum alloy.

[0006] In terms of corrosion resistance optimization: Cr and Mn can form a dense oxide film; the addition of rare earth elements can form intermetallic compounds with aluminum, thickening the grain boundary transition layer, reducing the corrosion of grain boundaries, and improving the stability of the surface oxide film during the processing.

[0007] The addition of B is mainly to eliminate the influence of residual impurity iron, refine the grains at the same time, and form TiB2 heterogeneous nucleation points with Ti to ensure plasticity during processing and use, and improve the fatigue resistance.

[0008] The impurity components are metal elements such as Fe, Zn, Na, etc. and non-metal elements such as Cl, H, etc. The excessive amount of impurity components will lead to a decline in mechanical properties or corrosion resistance. For example, the presence of Fe will form coarse acicular AlFe phase or Al-Fe-Si phase in the phase structure of aluminum profiles, increasing the brittleness of aluminum profiles; the same is true for Zn and Na, which will also lead to brittleness or a decline in corrosion resistance; the presence of Cl will introduce pitting corrosion, and hydrogen will cause hydrogen embrittlement, etc. This solution balances the influence brought by impurity elements through the above components. For example, the negative impact brought by Fe is controlled by Si, Mn, and B, the negative impact brought by Zn is controlled by Cu, and the negative impact brought by Na is controlled by Ti, B, and rare earth elements, etc. The refinement of grains by Ti / Zr can reduce the tendency of local corrosion induced by Cl, etc. In this solution, the functions of each component are not single and fixed, and there is a synergistic effect.

[0009] Preferably, by weight percentage, the components of the high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes are: Mg 4.5%; Mn 0.7%; Si 0.5%; Zr 0.1%; La 0.1%; Ti 0.08%; Ce 0.05%; B 0.004%; Y 0.03%; Cr 0.2%; Cu 0.3%; V 0.08%; impurities <0.1%, and the balance is Al.

[0010] This solution also proposes a preparation method for the above high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes, including the following steps: Step (1) Alloy melting: Under a protective gas atmosphere, heat the pure aluminum ingot until it melts, then add Al-Mn, Al-Si, Al-Cr, and Al-V alloys according to the component measurements. After standing and melting, add pure Cu and Al-Zr. After melting, add pure Mg or Al-Mg alloy. After melting, stand to remove slag, then add Al-La, Al-Ce, and Al-Y alloys, and finally add Al-Ti-B alloy to obtain a prefabricated alloy melt; Step (2) Refining: Pass a purification gas into the prefabricated alloy melt, filter out the slag, and stand to obtain a refined alloy; Step (3) Forming preparation: The refined alloy is cast, homogenized, and then extruded to obtain a rough aluminum profile product for vehicle and ship boxes; Step (4) Preparation of finished aluminum profile: Solution-treat the rough aluminum profile product under a protective atmosphere, then perform aging treatment. After completion, perform mechanical polishing, and finally perform anodic oxidation and surface coating treatment to obtain a high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes.

[0011] Preferably, in step (1), heat the pure aluminum ingot to melt at 700°C - 720°C, then add Al-Mn, Al-Si, Al-Cr, and Al-V alloys according to the component measurements. After standing and melting, raise the temperature to 740°C - 760°C and add pure Cu and Al-Zr. After melting, lower the temperature to 720°C - 740°C, add pure Mg or Al-Mg alloy, and maintain the temperature until the prefabricated alloy is obtained.

[0012] The melting point of Al is relatively low, about 660°C. It melts first to form a liquid molten pool, providing a uniform medium for the dissolution of subsequent high-melting-point elements. The melting temperatures of Al-Mn, Al-Si, Al-Cr, and Al-V alloys are relatively low, and the temperature during the addition stage can be slightly lower, at 700°C - 720°C. Subsequently, when adding pure Cu and Al-Zr, the temperature needs to be raised, but during this process, it is also necessary to control the excessive growth of Al3Zr grains, and the temperature should be controlled at 740°C - 760°C. Since the oxidation rate of Mg increases sharply when >750°C, the temperature is lowered when adding Mg. Pure Mg needs to be pressed below the liquid level of the molten aluminum, and its oxidation needs to be prevented. Therefore, some fluxes need to be introduced on the surface of the melt to isolate oxygen. Finally, after Mg is completely dissolved, stand for 15 min - 30 min, and use the density difference to make the flux float, and then remove it.

[0013] Preferably, in step (1), the process of adding the pure Mg or Al-Mg alloy is as follows: Add a flux of 0.5% - 1% of the aluminum mass to the aluminum liquid, and then press the polished pure Mg or Al-Mg alloy block into the molten liquid surface 20 cm - 40 cm below in multiple times through a graphite bell. After melting, stand for 15 min - 30 min to remove the flux.

[0014] Preferably, the flux is a chloride-based flux or a fluoride-based flux.

[0015] The chloride-based flux can be RJ-2 flux, with the composition of 45% NaCl + 40% KCl + 15% Na3AlF6. In step (2) of this solution, a purification gas is introduced and the process of filtering slag is carried out. In addition to the method of controlling the Cl content mentioned for Ti / Zr above, in this solution, rare earth elements can form highly stable chlorides with the remaining Cl, preventing the Cl diffusion path and enhancing the corrosion resistance of the final product. In addition, the multifunctional characteristics of rare earth can also improve the compactness of the oxide film and further enhance the corrosion resistance.

[0016] Preferably, in step (1), the process of adding the pure Mg or Al-Mg alloy is as follows: winding the measured Mg bars or Mg-Al alloy metal strips around the tungsten rod to obtain a magnesium-tungsten composite, and then putting the magnesium-tungsten composite into the melt.

[0017] The tungsten alloy has an extremely high melting point. Winding the Mg bars around the tungsten rod, the overall density after winding is between Al and tungsten. As the Mg bars melt into the aluminum melt, the tungsten rod sinks, and Mg is always melted out and floats during the sinking process, making the distribution of Mg in the melt more uniform and reducing segregation. Generally, the pressing method needs to press the magnesium ingot into the aluminum liquid, with a large exposed area, and the oxidation loss rate is usually 15% - 25%. In this solution, the burning loss rate is reduced to 5% - 8%. And because tungsten has poor compatibility with Al and Mg, the sunk tungsten rod can be easily taken out, cleaned and reused.

[0018] Preferably, the density of the magnesium-tungsten composite > 2.4 g / cm 3 。

[0019] Preferably, in the magnesium-tungsten composite, potassium fluoroaluminate is coated on the surface of the Mg bars.

[0020] Potassium fluoroaluminate can reduce the oxidation of Mg bars. Potassium fluoroaluminate can be filtered out during the later static slag removal process.

[0021] Preferably, the purification gas in step (2) is Ar doped with 0.3% - 0.5% by volume of Cl2 or SF6.

[0022] The purification gas is Ar doped with a small amount of Cl2, which can specifically remove H2, alkali metals and oxide inclusions and enhance the corrosion resistance. In this solution, rare earth elements such as La are added, which can control the finally remaining free chlorine. The purification gas can also be Ar doped with a small amount of N2 or CO2 or SF6.

[0023] Preferably, the homogenization treatment process in step (3) is to keep warm at 450 °C - 480 °C for 10 h - 12 h and then water quench.

[0024] The purpose of homogenization treatment is to eliminate dendritic segregation and stabilize the Al3Zr and Mg3Si phases.

[0025] Preferably, in step (4), the protective atmosphere is Ar; the temperature of the solution treatment is 530°C to 540°C; the aging treatment process is: heat preservation for 4h to 6h under the condition of 110°C to 130°C, and then heat preservation for 18h under the condition of 150°C to 170°C; the current density of anodic oxidation is 1.5A / dm 2 ~2.0A / dm 2 。

[0026] The time of solution treatment is related to the thickness of the profile. When the thickness is less than 3 mm, the heat preservation time is 30min - 45 min. When it is higher than 3mm, for every 1mm increase, the heat preservation time increases by 10min to 15min; the aging of the first-stage process is to promote homogeneous nucleation, and the aging of the second-stage process is to precipitate Al 3（ La, Ce) and other rare earth nanoparticles.

[0027] Preferably, in step (4), the surface roughness after mechanical polishing: Ra ≤ 1.0μm.

[0028] Compared with the prior art, the advantages of this solution are as follows: 1. In terms of components: By introducing rare earth elements and their interaction with other alloy elements, the mechanical properties and corrosion resistance of aluminum profiles are improved.

[0029] 2. In terms of process: Based on the components, after introducing rare earth elements, there are significant differences in temperature control, time control, etc. compared with the process of conventional components.

[0030] 3. Component homogenization: Adding magnesium element in the form of magnesium-tungsten complex can reduce the burning loss rate of magnesium and improve the homogenization of composition at the same time. Specific embodiments

[0031] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0032] Example 1 The components (mass percentage) of an aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes are as follows: Mg 4.5%; Mn 0.7%; Si 0.5%; Zr 0.1%; La 0.1%; Ti 0.08%; Ce 0.05%; B 0.004%; Y 0.03%; Cr 0.2%; Cu 0.3%; V 0.08%; impurities 0.08%; the balance is aluminum; It is prepared by the following method: Step (1) Alloy melting: Under the protective gas atmosphere, pure aluminum ingots are heated and melted at 700 °C. Subsequently, according to the component measurement, Al-Mn, Al-Si, Al-Cr, and Al-V alloys are added. After standing and melting, the temperature is raised to 750 °C, pure Cu and Al-Zr are added. After melting, the temperature is lowered to 720 °C, and pure Mg is added. After melting, it stands to remove slag, and then Al-La, Al-Ce, and Al-Y alloys are added. Finally, Al-Ti-B alloy is added to obtain a prefabricated alloy melt; The process of adding pure Mg is as follows: A flux accounting for 0.8% of the mass of aluminum is added to the aluminum liquid. Subsequently, through a graphite bell, polished pure Mg or Al-Mg alloy blocks are pressed into the molten liquid surface at a depth of 30 cm in multiple times, and after melting, it stands for 30 min to remove the flux. The flux is a chloride-based flux RJ-2 flux; Step (2) Refining: A purification gas of Ar doped with 0.4% by volume of Cl2 is introduced into the prefabricated alloy melt, the slag is filtered out, and it stands to obtain a refined alloy; Step (3) Forming preparation: The refined alloy is cast, held at 460 °C for 11 h, then subjected to water quenching homogenization treatment, and extruded to obtain a rough product of the aluminum profile for vehicle and ship boxes; Step (4) Preparation of the finished aluminum profile: The rough aluminum profile product is subjected to solution treatment by holding at 530 °C for 60 min under an Ar protective atmosphere, and then aging treatment, holding at 120 °C for 6 h, and then holding at 160 °C for 18 h. After completion, mechanical polishing is carried out to obtain a surface roughness of Ra 0.5 μm. Finally, anodic oxidation is carried out under the condition of a current density of 1.6 A / dm 2 condition, and surface coating treatment is carried out to obtain an aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes.

[0033] Example 2 The components (mass percentage) of an aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes are as follows: Mg 4.5%; Mn 0.7%; Si 0.5%; Zr 0.1%; La 0.1%; Ti 0.08%; Ce 0.05%; B 0.004%; Y 0.03%; Cr 0.2%; Cu 0.3%; V 0.08%; impurities 0.08%; the balance is aluminum; It is prepared by the following method: Step (1) Alloy melting: Under a protective gas atmosphere, pure aluminum ingots are heated and melted at 700 °C. Subsequently, according to the component measurement, Al-Mn, Al-Si, Al-Cr, and Al-V alloys are added. After standing and melting, the temperature is raised to 750 °C, and pure Cu and Al-Zr are added. After melting, the temperature is lowered to 720 °C, and pure Mg is added. After melting, it is left to stand and slag is removed. Then, Al-La, Al-Ce, and Al-Y alloys are added, and finally, Al-Ti-B alloy is added to obtain a prefabricated alloy melt; The process of adding pure Mg is as follows: The measured Mg strips are wound around the surface of a tungsten rod to obtain a magnesium-tungsten composite, and then the magnesium-tungsten composite is put into the melt; the density of the magnesium-tungsten composite is 2.5 g / cm 3 ; in the magnesium-tungsten composite, the surface of the Mg strip is coated with potassium fluoroaluminate; Step (2) Refining: A purification gas containing 0.4% by volume of Cl2 in Ar is introduced into the prefabricated alloy melt, the slag is filtered out, and it is left to stand to obtain a refined alloy; Step (3) Forming preparation: The refined alloy is cast, heat-insulated at 460 °C for 11 h, then subjected to water quenching and homogenization treatment, and extruded to obtain a rough product of aluminum profiles for vehicle and ship boxes; Step (4) Preparation of finished aluminum profiles: The rough aluminum profile products are solution-treated at 530 °C for 60 min under an Ar protective atmosphere, and then subjected to aging treatment, heat-insulated at 120 °C for 6 h, and then heat-insulated at 160 °C for 18 h. After completion, mechanical polishing is carried out to obtain a surface roughness of Ra 0.5 μm. Finally, anodic oxidation is carried out under the condition of a current density of 1.6 A / dm 2 conditions, and surface coating treatment is carried out to obtain high-strength and corrosion-resistant aluminum profiles for vehicle and ship boxes.

[0034] Example 3 The components (mass percentage) of a high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes are: Mg 4.6%; Mn 0.8%; Si 0.6%; Zr 0.12%; La 0.09%; Ti 0.09%; Ce 0.04%; B 0.004%; Y 0.02%; Cr 0.18%; Cu 0.32%; V 0.08%; the impurity component is 0.09%; the balance is Al; It is prepared by the following method: Step (1) Alloy melting: Under a protective gas atmosphere, pure aluminum ingots are heated and melted at 710 °C. Subsequently, according to the component measurement, Al-Mn, Al-Si, Al-Cr, and Al-V alloys are added. After standing and melting, the temperature is raised to 745 °C, and pure Cu and Al-Zr are added. After melting, the temperature is lowered to 725 °C, and pure Mg is added. After melting, it is left to stand and slag is removed. Then, Al-La, Al-Ce, and Al-Y alloys are added, and finally, Al-Ti-B alloy is added to obtain a prefabricated alloy melt; The process of adding pure Mg is as follows: flux accounting for 0.8% of the mass of aluminum is added to the molten aluminum. Subsequently, polished pure Mg or Al-Mg alloy blocks are pressed into the molten liquid surface at a depth of 40 cm in multiple times through a graphite bell. After melting, it is left standing for 20 minutes, and then the flux is removed. The flux is a chloride-based flux RJ-2 flux. Step (2) Refining: A purification gas of Ar doped with 0.5% by volume of Cl2 is introduced into the prefabricated alloy melt, the molten slag is filtered out, and it is left standing to obtain a refined alloy. Step (3) Forming preparation: The refined alloy is cast, kept at 470 °C for 11 h, then subjected to water quenching homogenization treatment and extrusion forming to obtain a rough aluminum profile product for vehicle and ship boxes. Step (4) Preparation of finished aluminum profile: The rough aluminum profile product is subjected to solution treatment by keeping it at 530 °C for 60 min under an Ar protection atmosphere, and then aging treatment is carried out. It is kept at 125 °C for 5 h, and then kept at 155 °C for 18 h. After completion, mechanical polishing is carried out to obtain a surface roughness of Ra of 0.8 μm. Finally, anodic oxidation is carried out under the condition of a current density of 1.8 A / dm 2 condition, and surface coating treatment is carried out to obtain a high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes.

[0035] Example 4 The components (mass percentage) of a high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes are as follows: Mg 4.6%; Mn 0.8%; Si 0.6%; Zr 0.12%; La 0.09%; Ti 0.09%; Ce 0.04%; B 0.004%; Y 0.02%; Cr 0.18%; Cu 0.32%; V 0.08%; the impurity component is 0.09%; the balance is Al. It is prepared by the following method: Step (1) Alloy melting: Under a protective gas atmosphere, pure aluminum ingots are heated and melted at 710 °C. Subsequently, according to the component measurement, Al-Mn, Al-Si, Al-Cr, and Al-V alloys are added. After standing and melting, the temperature is raised to 745 °C, pure Cu and Al-Zr are added. After melting, the temperature is lowered to 725 °C, pure Mg is added. After melting, the slag is removed by standing. Then, Al-La, Al-Ce, and Al-Y alloys are added. Finally, an Al-Ti-B alloy is added to obtain a prefabricated alloy melt. The process of adding pure Mg is as follows: The measured Mg strips are wound around the surface of a tungsten rod to obtain a magnesium-tungsten composite body, and then the magnesium-tungsten composite body is put into the melt; the density of the magnesium-tungsten composite body is 2.8 g / cm 3 ; in the magnesium-tungsten composite body, the surface of the Mg strip is coated with potassium fluoroaluminate. Step (2) Refining: A purification gas of Ar doped with 0.5% by volume of Cl2 is introduced into the prefabricated alloy melt, the molten slag is filtered out, and it is left standing to obtain a refined alloy. Step (3) Forming Preparation: The refined alloy is cast, held at 470 °C for 11 h, then subjected to water quenching homogenization treatment and extrusion molding to obtain a rough aluminum profile product for vehicle and ship boxes. Step (4) Preparation of Finished Aluminum Profile: The rough aluminum profile product is subjected to solution treatment by holding at 530 °C for 60 min under an Ar protective atmosphere, followed by aging treatment. It is held at 125 °C for 5 h and then at 155 °C for 18 h. After completion, it is mechanically polished to obtain a surface roughness of Ra of 0.8 μm, and finally anodized under a current density of 1.8 A / dm 2 condition and surface coating treatment are carried out to obtain a high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes.

[0036] Example Five The components (mass percentage) of a high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes are as follows: Mg 4.3%; Mn 0.7%; Si 0.6%; Zr 0.14%; La 0.11%; Ti 0.08%; Ce 0.06%; B 0.005%; Y 0.03%; Cr 0.18%; Cu 0.4%; V 0.07%; the impurity component is 0.10%; the balance is Al; It is prepared by the following method: Step (1) Alloy Melting: Under a protective gas atmosphere, pure aluminum ingots are heated and melted at 720 °C. Subsequently, according to the component measurement, Al-Mn, Al-Si, Al-Cr, and Al-V alloys are added. After standing and melting, the temperature is raised to 760 °C, and pure Cu and Al-Zr are added. After melting, the temperature is lowered to 740 °C, and pure Mg is added. After melting, it is left to stand and slag is removed. Then, Al-La, Al-Ce, and Al-Y alloys are added, and finally, Al-Ti-B alloy is added to obtain a prefabricated alloy melt. The process of adding pure Mg is as follows: A flux accounting for 0.8% of the mass of aluminum is added to the molten aluminum. Subsequently, polished Al-Mg alloy blocks are pressed into the molten surface layer by layer through a graphite bell to a depth of 25 cm below the molten surface. After melting, it is left to stand for 30 minutes, and the flux is removed. The flux is a chloride-based flux RJ-2 flux. Step (2) Refining: A purification gas containing 0.5% (volume ratio) Cl2 in Ar is introduced into the prefabricated alloy melt, the molten slag is filtered out, and it is left to stand to obtain a refined alloy. Step (3) Forming Preparation: The refined alloy is cast, held at 470 °C for 12 h, then subjected to water quenching homogenization treatment and extrusion molding to obtain a rough aluminum profile product for vehicle and ship boxes. Step (4) Preparation of finished aluminum profiles: The rough aluminum profiles are subjected to solution treatment by holding at 535 °C for 60 min under an Ar protective atmosphere, followed by aging treatment. They are held at 120 °C for 6 h and then at 155 °C for 18 h. After completion, mechanical polishing is carried out to obtain a surface roughness of Ra of 0.8 μm. Finally, anodic oxidation is carried out under a current density of 1.9 A / dm 2 conditions, and surface coating treatment is performed to obtain aluminum profiles for high-strength and corrosion-resistant vehicle and ship boxes.

[0037] Example 6 The components (mass percentage) of an aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes are as follows: Mg 4.5%; Mn 0.7%; Si 0.5%; Zr 0.1%; La 0.1%; Ti 0.08%; Ce 0.05%; B 0.004%; Y 0.03%; Cr 0.2%; Cu 0.3%; V 0.08%; impurities are 0.08%; the balance is aluminum; It is prepared by the following method: Step (1) Alloy melting: Under a protective gas atmosphere, pure aluminum ingots are heated and melted at 700 °C. Subsequently, according to the component measurement, Al-Mn, Al-Si, Al-Cr, and Al-V alloys are added. After standing and melting, the temperature is raised to 750 °C, and pure Cu and Al-Zr are added. After melting, the temperature is lowered to 720 °C, and pure Mg is added. After melting, slag is removed by standing, and then Al-La, Al-Ce, and Al-Y alloys are added. Finally, an Al-Ti-B alloy is added to obtain a precast alloy melt; The process of adding pure Mg is as follows: The measured Mg strips are wound around the surface of a tungsten rod to obtain a magnesium-tungsten composite, and then the magnesium-tungsten composite is put into the melt; the density of the magnesium-tungsten composite is 2.8 g / cm 3 ; in the magnesium-tungsten composite, the surface of the Mg strip is coated with potassium fluoroaluminate; Step (2) Refining: A purification gas of Ar doped with 0.4% by volume of Cl2 is introduced into the precast alloy melt, the slag is filtered out, and after standing, a refined alloy is obtained; Step (3) Molding preparation: The refined alloy is cast, held at 460 °C for 11 h, then subjected to water quenching and homogenization treatment, and extruded to obtain rough aluminum profiles for vehicle and ship boxes; Step (4) Preparation of finished aluminum profiles: The rough aluminum profiles are subjected to solution treatment by holding at 530 °C for 60 min under an Ar protective atmosphere, followed by aging treatment. They are held at 120 °C for 6 h and then at 160 °C for 18 h. After completion, mechanical polishing is carried out to obtain a surface roughness of Ra 0.5 μm. Finally, anodic oxidation is carried out under a current density of 1.6 A / dm 2 conditions, and surface coating treatment is performed to obtain aluminum profiles for high-strength and corrosion-resistant vehicle and ship boxes.

[0038] Comparative Example 1 The components (by mass percentage) of an aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes are as follows: Mg 5.5%; Mn 0.7%; Si 0.5%; Zr 0.1%; La 0.1%; Ti 0.08%; Ce 0.05%; B 0.004%; Y 0.03%; Cr 0.2%; Cu 0.3%; V 0.08%; impurities are 0.10%; the rest is aluminum; It is prepared by the following method: Step (1) Alloy melting: Under the protective gas atmosphere, the pure aluminum ingot is heated and melted at 700°C. Subsequently, according to the component measurement, Al-Mn, Al-Si, Al-Cr, and Al-V alloys are added. After standing and melting, the temperature is raised to 750°C, and pure Cu and Al-Zr are added. After melting, the temperature is lowered to 720°C, and pure Mg is added. After melting, slag is removed by standing. Then, Al-La, Al-Ce, and Al-Y alloys are added. Finally, Al-Ti-B alloy is added to obtain a precast alloy melt; The process of adding pure Mg is as follows: A flux of 0.8% of the aluminum mass is added to the aluminum liquid. Subsequently, the polished pure Mg or Al-Mg alloy block is pressed into the molten liquid surface 30 cm below in multiple times through a graphite bell, and after melting, it stands for 30 min, and the flux is removed. The flux is a chloride-based flux RJ-2 flux; Step (2) Refining: A purification gas of Ar doped with 0.4% by volume of Cl2 is introduced into the precast alloy melt, the slag is filtered out, and after standing, a refined alloy is obtained; Step (3) Forming preparation: The refined alloy is cast, heat-insulated at 460°C for 11 h, then subjected to water quenching homogenization treatment, and extruded to obtain a rough product of the aluminum profile for vehicle and ship boxes; Step (4) Preparation of the finished aluminum profile: The rough product of the aluminum profile is subjected to solution treatment by heat-insulating at 530°C for 60 min under the Ar protective atmosphere, and then aging treatment is carried out, heat-insulated at 120°C for 6 h, and then heat-insulated at 160°C for 18 h. After completion, mechanical polishing is carried out to obtain a surface roughness of Ra 0.5 μm. Finally, anodic oxidation is carried out under the condition of a current density of 1.6 A / dm 2 condition, and surface coating treatment is carried out to obtain an aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes.

[0039] Comparative Example 2 The components (by mass percentage) of an aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes are as follows: Mg 3.5%; Mn 0.7%; Si 0.5%; Zr 0.1%; La 0.1%; Ti 0.08%; Ce 0.05%; B 0.004%; Y 0.03%; Cr 0.2%; Cu 0.3%; V 0.08%; impurities are 0.10%; the rest is aluminum; It is prepared by the following method: Step (1) Alloy melting: Under a protective gas atmosphere, pure aluminum ingots are heated and melted at 700 °C. Subsequently, according to the component measurement, Al-Mn, Al-Si, Al-Cr, and Al-V alloys are added. After standing and melting, the temperature is raised to 750 °C, and pure Cu and Al-Zr are added. After melting, the temperature is lowered to 720 °C, and pure Mg is added. After melting, slag is removed by standing. Then, Al-La, Al-Ce, and Al-Y alloys are added. Finally, Al-Ti-B alloy is added to obtain a prefabricated alloy melt; The process of adding pure Mg is as follows: A flux accounting for 0.8% of the mass of aluminum is added to the aluminum liquid. Subsequently, polished pure Mg or Al-Mg alloy blocks are pressed into the molten liquid surface by a graphite bell in multiple times to a depth of 30 cm below the molten liquid surface. After melting, it stands for 30 min, and the flux is removed. The flux is a chloride-based flux RJ-2 flux; Step (2) Refining: A purification gas of Ar doped with 0.4% by volume of Cl2 is introduced into the prefabricated alloy melt, the slag is filtered out, and it stands to obtain a refined alloy; Step (3) Forming preparation: The refined alloy is cast, heat-preserved at 460 °C for 11 h, then subjected to water quenching and homogenization treatment, and extruded to obtain a rough aluminum profile product for vehicle and ship boxes; Step (4) Preparation of finished aluminum profile: The rough aluminum profile product is subjected to solution treatment by heat-preserving at 530 °C for 60 min under an Ar protective atmosphere, and then subjected to aging treatment, heat-preserved at 120 °C for 6 h, and then heat-preserved at 160 °C for 18 h. After completion, mechanical polishing is carried out to obtain a surface roughness of Ra 0.5 μm. Finally, anodic oxidation is carried out under the condition of a current density of 1.6 A / dm 2 condition, and surface coating treatment is carried out to obtain a high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes.

[0040] Comparative Example 3 The components (mass percentage) of a high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes are: Mg 4.5%; Mn 0.7%; Si 0.5%; Zr 0.1%; Ti 0.08%; B 0.004%; Cr 0.2%; Cu 0.3%; V 0.08%; impurities are 0.08%; the rest is aluminum; It is prepared by the following method: Step (1) Alloy melting: Under a protective gas atmosphere, pure aluminum ingots are heated and melted at 700 °C. Subsequently, according to the component measurement, Al-Mn, Al-Si, Al-Cr, and Al-V alloys are added. After standing and melting, the temperature is raised to 750 °C, and pure Cu and Al-Zr are added. After melting, the temperature is lowered to 720 °C, and pure Mg is added. After melting, slag is removed by standing. Finally, Al-Ti-B alloy is added to obtain a prefabricated alloy melt; The process of adding pure Mg is as follows: Add a flux accounting for 0.8% of the mass of aluminum to the molten aluminum. Subsequently, press polished pure Mg or Al-Mg alloy blocks into the molten surface at a depth of 30 cm below the molten surface in multiple times through a graphite bell. After melting, let it stand for 30 min, and then remove the flux. The flux is a chloride-based flux RJ-2 flux. Step (2) Refining: Pass a purification gas of Ar doped with 0.4% by volume of Cl2 into the precast alloy melt, filter out the slag, and let it stand to obtain a refined alloy. Step (3) Forming preparation: After casting the refined alloy, keep it at 460 °C for 11 h, then perform water quenching homogenization treatment, and extrude it to obtain a rough product of aluminum profiles for vehicle and ship boxes. Step (4) Preparation of finished aluminum profiles: Solution treat the rough aluminum profiles at 530 °C for 60 min under an Ar protection atmosphere, then perform aging treatment, keep it at 120 °C for 6 h, and then keep it at 160 °C for 18 h. After completion, perform mechanical polishing to obtain a surface roughness of Ra 0.7 μm. Finally, perform anodic oxidation at a current density of 1.6 A / dm2 and perform surface coating treatment to obtain high-strength and corrosion-resistant aluminum profiles for vehicle and ship boxes.

[0041] Comparative Example 4 The components (mass percentage) of a high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes are as follows: Mg 4.5%; Mn 0.7%; Si 0.5%; Zr 0.1%; La 0.1%; Ti 0.08%; Ce 0.05%; B 0.004%; Y 0.03%; Cr 0.2%; Cu 0.3%; V 0.08%; the impurities are 0.08%; the rest is aluminum. It is prepared by the following method: Step (1) Alloy melting: Under a protective gas atmosphere, heat and melt pure aluminum ingots at 700 °C. Subsequently, according to the component measurement, add Al-Mn, Al-Si, Al-Cr, and Al-V alloys. After standing and melting, raise the temperature to 780 °C and add pure Cu and Al-Zr. Subsequently, add pure Mg. After melting, let it stand to remove the slag, and then add Al-La, Al-Ce, and Al-Y alloys. Finally, add Al-Ti-B alloy to obtain a precast alloy melt. The process of adding pure Mg is as follows: Add a flux accounting for 0.8% of the mass of aluminum to the molten aluminum. Subsequently, press polished pure Mg or Al-Mg alloy blocks into the molten surface at a depth of 30 cm below the molten surface in multiple times through a graphite bell. After melting, let it stand for 30 min, and then remove the flux. The flux is a chloride-based flux RJ-2 flux. Step (2) Refining: Pass a purification gas of Ar doped with 0.4% by volume of Cl2 into the precast alloy melt, filter out the slag, and let it stand to obtain a refined alloy. Step (3) Forming preparation: The refined alloy is cast, held at 460 °C for 11 h, then subjected to water quenching homogenization treatment and extrusion forming to obtain a rough product of aluminum profiles for vehicle and ship boxes. Step (4) Preparation of finished aluminum profiles: The rough aluminum profile product is solution-treated at 530 °C for 60 min under an Ar protective atmosphere, followed by aging treatment, held at 120 °C for 6 h, then held at 160 °C for 18 h. After completion, mechanical polishing is carried out to obtain a surface roughness of Ra 0.5 μm, and finally 2 anodic oxidation is carried out under the condition of a current density of 1.6 A / dm

[0042] Comparative Example 5 The components (mass percentage) of a high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes are as follows: Mg 4.5%; Mn 0.7%; Si 0.5%; Zr 0.1%; La 0.1%; Ti 0.08%; Ce 0.05%; B 0.004%; Y 0.03%; Cr 0.2%; Cu 0.3%; V 0.08%; impurities are 0.08%; the rest is aluminum. It is prepared by the following method: Step (1) Alloy melting: Under a protective gas atmosphere, pure aluminum ingots are heated and melted at 700 °C. Subsequently, according to the component measurement, Al-Mn, Al-Si, Al-Cr, and Al-V alloys are added. After standing and melting, the temperature is raised to 750 °C, and pure Cu and Al-Zr are added. After melting, the temperature is lowered to 720 °C, and pure Mg is added. After melting, standing and slag removal are carried out, and then Al-La, Al-Ce, and Al-Y alloys are added. Finally, the Al-Ti-B alloy is added to obtain a precast alloy melt. The process of adding pure Mg is as follows: The measured Mg strips are wound around the surface of a tungsten rod to obtain a magnesium-tungsten composite, and then the magnesium-tungsten composite is put into the melt; the density of the magnesium-tungsten composite is 2.1 g / cm 3 ; Step (2) Refining: A purification gas of Ar doped with 0.4% by volume of Cl2 is introduced into the precast alloy melt, the slag is filtered out, and then standing is carried out to obtain a refined alloy. Step (3) Forming preparation: The refined alloy is cast, held at 460 °C for 11 h, then subjected to water quenching homogenization treatment and extrusion forming to obtain a rough product of aluminum profiles for vehicle and ship boxes. Step (4) Preparation of finished aluminum profiles: The rough aluminum profile product is solution-treated at 530 °C for 60 min under an Ar protective atmosphere, followed by aging treatment, held at 120 °C for 6 h, then held at 160 °C for 18 h. After completion, mechanical polishing is carried out to obtain a surface roughness of Ra 0.5 μm, and finally2 Anodize under the following conditions and perform surface coating treatment to obtain aluminum profiles for high-strength and corrosion-resistant vehicle and ship boxes.

[0043] Comparative Example 6 The components (mass percentage) of an aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes are as follows: Mg 4.5%; Mn 0.7%; Si 0.5%; Zr 0.1%; La 0.1%; Ti 0.08%; Ce 0.05%; B 0.004%; Y 0.03%; Cr 0.2%; Cu 0.3%; V 0.08%; impurities are 0.08%; the balance is aluminum; It is prepared by the following method: Step (1) Alloy melting: Under the protection gas atmosphere, heat and melt pure aluminum ingots at 700 °C, then add Al-Mn, Al-Si, Al-Cr, and Al-V alloys according to the component measurement. After standing and melting, raise the temperature to 750 °C and add pure Cu and Al-Zr. After melting, cool down to 720 °C, add pure Mg, stand and remove slag after melting, then add Al-La, Al-Ce, and Al-Y alloys, and finally add Al-Ti-B alloy to obtain a precast alloy melt; The process of adding pure Mg is as follows: Add a flux accounting for 0.8% of the mass of aluminum to the aluminum liquid, and then press polished pure Mg or Al-Mg alloy blocks through a graphite bell into the molten liquid surface at a depth of 30 cm in multiple times. After melting, stand for 30 min to remove the flux. The flux is a chloride-based flux RJ-2 flux; Step (2) Refining: Pass a purification gas of Ar doped with 0.4% by volume of Cl2 into the precast alloy melt, filter out the slag, and stand to obtain a refined alloy; Step (3) Forming preparation: The refined alloy is cast, heat-insulated at 460 °C for 11 h, then subjected to water quenching homogenization treatment, and extruded to obtain a rough product of aluminum profiles for vehicle and ship boxes; Step (4) Preparation of finished aluminum profiles: Subject the rough aluminum profile product to solution treatment by heat-insulating at 550 °C for 60 min under an Ar protection atmosphere, then perform aging treatment, heat-insulate at 180 °C for 18 h, polish mechanically after completion to obtain a surface roughness of Ra 0.5 μm, and finally perform anodization under the condition of a current density of 1.6 A / dm 2 Anodize under the following conditions and perform surface coating treatment to obtain aluminum profiles for high-strength and corrosion-resistant vehicle and ship boxes.

[0044] Comparative Example 7 The components (mass percentage) of an aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes are as follows: Mg 4.5%; Mn 0.7%; Si 0.5%; Zr 0.1%; La 0.1%; Ti 0.08%; Ce 0.05%; B 0.004%; Y 0.03%; Cr 0.2%; Cu 0.3%; V 0.08%; impurities are 0.08%; the rest is aluminum; It is prepared by the following method: Step (1) Alloy melting: Under the atmosphere of protective gas, pure aluminum ingots are heated and melted at 700 °C. Subsequently, according to the component measurement, Al-Mn, Al-Si, Al-Cr and Al-V alloys are added. After standing and melting, the temperature is raised to 750 °C, and pure Cu and Al-Zr are added. After melting, the temperature is lowered to 720 °C, and pure Mg is added. After melting, slag is removed by standing. Then, Al-La, Al-Ce, and Al-Y alloys are added. Finally, Al-Ti-B alloy is added to obtain a precast alloy melt; The process of adding pure Mg is as follows: A flux accounting for 0.8% of the mass of aluminum is added to the aluminum liquid. Subsequently, through a graphite bell, polished pure Mg or Al-Mg alloy blocks are pressed into the molten liquid surface at a depth of 30 cm in multiple times, and after melting, they are left standing for 30 min to remove the flux. The flux is a chloride-based flux RJ-2 flux; Step (2) Refining: A purification gas mixed with Ar with a volume ratio of 0.4% Cl2 is introduced into the precast alloy melt, the slag is filtered out, and after standing, a refined alloy is obtained; Step (3) Forming preparation: The refined alloy is cast, heat-preserved at 460 °C for 11 h, then subjected to water quenching and homogenization treatment, and extruded to obtain a rough product of aluminum profile for vehicle and ship boxes; Step (4) Preparation of finished aluminum profile: The rough aluminum profile product is subjected to solution treatment by heat-preserving at 530 °C for 60 min under an Ar protection atmosphere, and then subjected to aging treatment by heat-preserving at 180 °C for 18 h. After completion, mechanical polishing is carried out to obtain a surface roughness of Ra 1.3 μm. Finally, anodic oxidation is carried out under the condition of a current density of 1.6 A / dm 2 condition, and surface coating treatment is carried out to obtain an aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes.

[0045] Comparative Example 8 The components (mass percentage) of an aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes are as follows: Mg 4.5%; Mn 0.7%; Si 0.5%; Zr 0.1%; La 0.1%; Ti 0.08%; Ce 0.05%; B 0.004%; Y 0.03%; Cr 0.2%; Cu 0.3%; V 0.08%; impurities are 0.08%; the rest is aluminum; It is prepared by the following method: Step (1) Alloy melting: Under a protective gas atmosphere, pure aluminum ingots are heated and melted at 700 °C. Subsequently, according to the component measurement, Al-Mn, Al-Si, Al-Cr, and Al-V alloys are added. After standing and melting, the temperature is raised to 750 °C, and pure Cu and Al-Zr are added. After melting, the temperature is lowered to 720 °C, and pure Mg is added. After melting, slag is removed by standing. Then, Al-La, Al-Ce, and Al-Y alloys are added, and finally, Al-Ti-B alloy is added to obtain a prefabricated alloy melt; The process of adding pure Mg is as follows: A flux accounting for 0.8% of the mass of aluminum is added to the molten aluminum. Subsequently, polished pure Mg or Al-Mg alloy blocks are pressed into the molten liquid surface at a depth of 30 cm below the surface in multiple times through a graphite bell. After melting, it stands for 30 min, and the flux is removed. The flux is a chloride-based flux RJ-2 flux; Step (2) Refining: A purification gas containing 0.2% by volume of Cl2 in Ar is introduced into the prefabricated alloy melt, the slag is filtered out, and it stands to obtain a refined alloy; Step (3) Forming preparation: The refined alloy is cast, held at 460 °C for 11 h, then subjected to water quenching homogenization treatment and extrusion forming to obtain a rough aluminum profile product for vehicle and ship boxes; Step (4) Preparation of finished aluminum profile: The rough aluminum profile product is solution-treated at 530 °C for 60 min under an Ar protective atmosphere, followed by aging treatment, held at 120 °C for 6 h, and then held at 160 °C for 18 h. After completion, mechanical polishing is carried out to obtain a surface roughness of Ra 0.5 μm. Finally, anodic oxidation is carried out under the condition of a current density of 1.6 A / dm 2 condition, and surface coating treatment is carried out to obtain a high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes.

[0046] Comparative Example Nine The components (mass percentage) of a high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes are as follows: Mg 4.5%; Mn 0.7%; Si 0.5%; Zr 0.1%; La 0.1%; Ti 0.08%; Ce 0.05%; B 0.004%; Y 0.03%; Cr 0.2%; Cu 0.3%; V 0.08%; impurities are 0.08%; the rest is aluminum; It is prepared by the following method: Step (1) Alloy melting: Under a protective gas atmosphere, pure aluminum ingots are heated and melted at 700 °C. Subsequently, according to the component measurement, Al-Mn, Al-Si, Al-Cr, and Al-V alloys are added. After standing and melting, the temperature is raised to 750 °C, and pure Cu and Al-Zr are added. After melting, the temperature is lowered to 720 °C, and pure Mg is added. After melting, slag is removed by standing. Then, Al-La, Al-Ce, and Al-Y alloys are added, and finally, Al-Ti-B alloy is added to obtain a prefabricated alloy melt; The process of adding pure Mg is as follows: Add a flux accounting for 0.8% of the mass of aluminum to the molten aluminum. Subsequently, press polished pure Mg or Al-Mg alloy blocks into the molten aluminum surface through a graphite bell at multiple times to a depth of 30 cm below the molten surface. After melting, let it stand for 30 min, and then remove the flux. The flux is a chloride-based flux RJ-2 flux. Step (2) Refining: Pass a purification gas of Ar doped with Cl2 with a volume ratio of 0.4% into the prefabricated alloy melt, filter out the slag, and let it stand to obtain a refined alloy. Step (3) Forming preparation: The refined alloy is cast, kept at 460 °C for 11 h, then subjected to water quenching homogenization treatment, and extruded to obtain a rough aluminum profile product for vehicle and ship boxes. Step (4) Preparation of finished aluminum profile: Subject the rough aluminum profile product to solution treatment by keeping it at 530 °C for 60 min under an Ar protection atmosphere, then perform aging treatment, keep it at 120 °C for 6 h, and then keep it at 160 °C for 18 h. After completion, perform mechanical polishing to obtain a surface roughness of Ra 0.5 μm. Finally, perform anodic oxidation under the condition of a current density of 2.5 A / dm 2 and perform surface coating treatment to obtain a high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes.

[0047] The detection standards and targets are shown in Table 1, and the detection results are shown in Table 2.

[0048] Table 1 Table 2 From the results in Table 2, it can be seen that compared with Comparative Examples 1 to 9, Examples 1 to 6 have better strength and corrosion resistance. The industry has an allowable error value of ±5% for the salt spray test. At the same time, all the examples in this solution can meet the target requirements. Moreover, Example 2 is better than Example 1, and Example 4 is better than Example 3. Considering the Mg burn-off rate, it shows that the magnesium-tungsten composite structure proposed in this solution can more effectively control the composition and can obtain good strength and corrosion resistance. The overall performance difference between Example 6 and Example 2 is not significant.

[0049] The difference between Comparative Example 1 and Example 1 is that Mg is 5.5%, which is excessive, resulting in grain boundary embrittlement and coarse β-Mg2Si phase, and thus the tensile strength and salt spray test results are lower than the target values. The difference between Comparative Example 2 and Example 1 is that Mg is 3.5%, which is insufficient, resulting in a reduction of the β-Mg2Si strengthening phase, weakened sacrificial anode protection, and also a decrease in elongation. The difference between Comparative Example 3 and Example 1 is that no rare earth element is added, which increases the sensitivity of grain boundary corrosion and makes the oxide film not dense, also resulting in the tensile strength and salt spray test results being lower than the target values.

[0050] The difference between Comparative Example 4 and Example 1 is that the melting temperature is too high, reaching 780 °C, which will exacerbate the oxidation and burning loss of Mg and rare earth elements. Moreover, the addition of rare earth itself can reduce the melting temperature. Excessively high temperature will also lead to oversize grains, resulting in a decline in mechanical properties. The difference between Comparative Example 6 and Example 1 is that over-high solution temperature causes grain coarsening and overburning, thereby leading to poor elongation. The difference between Comparative Example 7 and Example 1 is that over-high aging temperature causes coarsening of the precipitated phase. All these illustrate that the addition of rare earth requires an appropriate reduction in temperature.

[0051] The difference between Comparative Example 5 and Example 2 is that the density of the magnesium-tungsten composite is too low, 2.1 g / cm³, and potassium fluoroaluminate is not coated on the surface of the magnesium strip, which increases the burning loss rate of magnesium and the salt spray test performance is lower than that of Example 2.

[0052] The difference between Comparative Example 8 and Example 1 is that a low proportion of Cl2 in the purified gas results in incomplete removal of the slag, an increase in the inclusion content, and it becomes the crack initiation source.

[0053] The difference between Comparative Example 9 and Example 1 is that the anodic oxidation current density is too large, causing the oxidation film to grow too fast, which will lead to an increase in porosity, and the high current causes local overheating and accelerates the oxidation of magnesium.

[0054] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve basically the same technical problems and achieve basically the same technical effects are all covered by the protection scope of the present invention.

Claims

1. An aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes, characterized in that, By mass percentage, it includes the following components: Mg 4.2% - 4.8%; Mn 0.6% - 0.9%; Si 0.4% - 0.7%; Zr 0.08%~0.15%； La 0.05% - 0.12%; Ti 0.06% - 0.10%; Ce 0.03% - 0.08%; B 0.003%~0.005%； Y 0.01%~0.04%； Cr 0.15%~0.25%； Cu 0.2% - 0.4%; V 0.05%~0.10%； Impurity components < 0.15%; The balance is Al.

2. A preparation method of an aluminum profile for a high-strength and corrosion-resistant vehicle and ship box body as described in claim 1, characterized in that, It includes the following steps: Step (1) Alloy melting: Under the protective gas atmosphere, heat the pure aluminum ingot to melt it, and then add Al-Mn, Al-Si, Al-Cr and Al-V alloys according to the component measurement. After standing and melting, add pure Cu and Al-Zr. After melting, add pure Mg or Al-Mg alloy. After melting, stand to remove slag, and then add Al-La, Al-Ce, Al-Y alloys. Finally, add Al-Ti-B alloy to obtain a prefabricated alloy melt; Step (2) Refining: Pass a purification gas into the prefabricated alloy melt, filter out the slag, and stand to obtain a refined alloy; Step (3) Forming preparation: The refined alloy is cast, homogenized, and then extruded to obtain a rough product of aluminum profile for vehicle and ship boxes; Step (4) Preparation of finished aluminum profile: The rough aluminum profile product is solution-treated under a protective atmosphere, then aged, mechanically polished after completion, and finally anodized and surface-coated to obtain a high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes.

3. The preparation method of the aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes according to claim 2, characterized in that, In step (1), the pure aluminum ingot is heated and melted at 700°C - 720°C, and then Al-Mn, Al-Si, Al-Cr and Al-V alloys are added according to the component measurement. After standing and melting, the temperature is raised to 740°C - 760°C to add pure Cu and Al-Zr. After melting, the temperature is lowered to 720°C - 740°C, and pure Mg or Al-Mg alloy is added and the temperature is maintained until a prefabricated alloy is obtained.

4. The preparation method of the aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes according to claim 2, characterized in that, In step (1), the process of adding the pure Mg or Al-Mg alloy is as follows: Add a flux of 0.5% - 1% of the aluminum mass to the molten aluminum, and then press the surface-polished pure Mg or Al-Mg alloy block into the molten liquid surface 20 cm - 40 cm below in multiple times through a graphite bell. After melting, stand for 15 min - 30 min to remove the flux; the flux is a chloride-based flux or a fluoride-based flux.

5. The preparation method of the high-strength and corrosion-resistant aluminum profile for vehicle and ship boxes according to claim 2, characterized in that In step (1), the process of adding the pure Mg or Al-Mg alloy is as follows: Wind the measured Mg strip or Mg-Al alloy metal strip around the surface of a tungsten rod to obtain a magnesium-tungsten composite, and then put the magnesium-tungsten composite into the melt.

6. The preparation method of the aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes according to claim 5, characterized in that, The density of the magnesium-tungsten composite is > 2.4 g / cm 3 ; in the magnesium-tungsten composite, potassium fluoroaluminate is coated on the surface of the magnesium strip.

7. The preparation method of the aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes according to claim 2, characterized in that The purification gas in step (2) is Ar doped with 0.3% - 0.5% by volume of Cl2 or SF6.

8. The preparation method of the aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes according to claim 2, characterized in that The homogenization treatment process in step (3) is to keep warm at 450°C - 480°C for 10 h - 12 h and then water quench.

9. The preparation method of the aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes according to claim 2, characterized in that, In step (4), the protective atmosphere is Ar; the solution treatment temperature is 530°C to 540°C; the aging treatment process is: heat preservation for 4h to 6h under the condition of 110°C to 130°C, and then heat preservation for 18h under the condition of 150°C to 170°C; the current density of anodic oxidation is 1.5A / dm 2 ~2.0A / dm 2 .

10. The preparation method of the aluminum profile for high-strength and corrosion-resistant vehicle and ship boxes according to claim 2, characterized in that, In step (4), the surface roughness after mechanical polishing: Ra ≤ 1.0 μm.

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