A method for manufacturing an aluminum alloy spherical crown, a corrosion-resistant aluminum alloy spherical crown, and a support

Abstract

This invention provides a method for preparing an aluminum alloy spherical crown, a corrosion-resistant aluminum alloy spherical crown, and a support. The method for preparing the aluminum alloy spherical crown includes: S1, blanking; S2, hot forming; S3, solution treatment; S4, cold deformation, where the blank obtained in S3 is placed into a second mold and cold-pressed to completely fill the mold, wherein the cold deformation amount is 2-4%; S5, aging. The method for preparing the corrosion-resistant aluminum alloy spherical crown of this invention, by performing cold deformation after solution treatment, can offset the thermal stress and residual stress generated by solution treatment, improving the dimensional stability of the spherical crown after machining. By optimizing the elemental composition of the aluminum alloy bar, the prepared aluminum alloy spherical crown has high strength, hardness, and corrosion resistance. The dimensions of the first and second molds allow for precise control of the deformation amount of each part of the spherical crown blank, resulting in uniform grain size and solving the problems of incomplete filling of the hot-forged metal and difficulty in demolding of the aluminum alloy spherical crown blank.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bridge construction, in particular to a preparation method of a corrosion-resistant aluminum alloy spherical crown, an aluminum alloy spherical crown and a support. BACKGROUND

[0002] Bridge supports are usually arranged between the piers and the girder of the bridge to bear pressure and horizontal load, and are key components in bridge construction. The spherical support has excellent load transmission performance and durability, and has been widely used in various bridge projects and has been generally recognized in the industry.

[0003] The spherical support is usually composed of an upper seat plate, a lower seat plate, a spherical crown lining plate and a non-metallic sliding plate. The displacement of the support is realized through the planar friction pair composed of the non-metallic sliding plate embedded in the stainless steel plate of the upper support plate and the spherical crown lining plate. The rotation of the support is realized through the spherical friction pair composed of the non-metallic sliding plate embedded in the lower seat plate and the circular surface of the spherical crown lining plate. In order to realize the same life design of the spherical support and the bridge main body, the long-term reliability of the spherical crown lining plate is particularly important.

[0004] The prior art usually uses rolled plates to manufacture aluminum alloy spherical crowns, but the grains in the plates are easily deformed and elongated along the rolling direction, resulting in poor uniformity of the plates, and the mechanical properties and corrosion resistance of the final product are anisotropic. At the same time, due to the limitation of equipment capacity, it is difficult to roll large-thickness plates that meet the requirements, and it is difficult to meet the use requirements in harsh working conditions. Or made by free forging process, first forged into a round pie and then processed into a spherical shape, the material utilization rate (about 50%) is low, and the cost is high. This technology can effectively eliminate anisotropy and has good uniformity, but due to high-temperature forging treatment, residual stress exists in the spherical crown structure, which will cause the local size of the spherical crown to be unstable and increase the friction coefficient of the friction pair after long-term use, affecting the translation and rotation of the support. At the same time, due to the unreasonable proportion of silicon, magnesium and copper elements, the corrosion resistance in acidic environment is poor.

[0005] Therefore, the present application is proposed. SUMMARY

[0006] The problem solved by the present application is that the existing aluminum alloy spherical crown has residual stress which affects the service life, and is not resistant to acidic medium corrosion, which limits the application scene.

[0007] To solve the above problems, the present application provides a preparation method of an aluminum alloy spherical crown, comprising:

[0008] S1, cutting an aluminum alloy bar stock into a segment with a diameter of d and a length of L to ensure that the weight of the segment is consistent with that of the spherical crown blank;

[0009] S2, hot forming the segment material obtained in step S1 to 470-510 DEG C and keeping warm, preheating the first mold to 200-300 DEG C and evenly smearing lubricating oil on the surface thereof; transferring the segment material into the first mold for hot pressing to make it fill the mold for forming, upsetting ratio R≥2.4, and then rapidly water cooling it to room temperature;

[0010] The deformation speed and single deformation amount of the mold pressing are strictly controlled during the hot pressing forming, the metal is ensured to flow smoothly and fill the first mold, the deformation is uniform and the internal structure of the blank is uniform, the total deformation amount reaches the design requirement, and the deformation amount for the final forming of the cold deformation is left, and the upsetting blank is made. Preferably, the lubricating oil is composed of 70-80% cylinder oil + 20-30% graphite. Preferably, the deformation rate in step S2 is 0.02-0.05 s -1 .

[0011] As an example of the present application, the diameter D1 of the first mold is 448 mm, the height H1 is 72 mm, the spherical center radius SR1 is 630 mm, and the slope W is 3°, which is easy to forge and can ensure that the forgings will not have defects such as misalignment and folding.

[0012] S3, solution treatment of the blank obtained in step S2 at 450-560 DEG C for 150-350 min, and then rapidly water cooling it to room temperature; the specific holding time is designed according to the maximum thickness of the blank, such as 3-5 min / mm; this step can make the blank temperature uniform and the precipitated phase fully dissolved.

[0013] S4, cold deformation of the blank obtained in S3 into the second mold to make the blank completely fill the second mold for cold pressing forming, wherein the cold deformation amount is 2-4%;

[0014] Generally, solution treatment will generate a lot of thermal stress and residual stress, which not only affects the corrosion resistance of the forgings, but also causes the local size of the parts to be unstable as the residual stress gradually releases over time; the present application adopts the process of hot die preforming and cold die final forging of the extruded rod, which not only eliminates the thermal stress and residual stress generated by solution treatment and realizes the precise and stable size of the spherical crown, but also improves the utilization rate of the material, reduces the manufacturing cost and has good corrosion resistance and mechanical properties.

[0015] S5, aging of the blank obtained in step S4 at 160-190 DEG C for at least 480 min. Through this aging operation, Mg and Si atoms are precipitated from the supersaturated solid solution to form an atomic enrichment zone, the strengthening phase is nucleated and grown, and the spherical crown obtains the best strengthening effect, and has good comprehensive mechanical properties and corrosion resistance.

[0016] Preferably, the aluminum alloy rod in step S1 has the following elemental composition: 0.4%-1.1% Si, 0-0.5% Fe, 0-0.1% Cu, 0.5%-0.9% Mn, 0.5%-1.1% Mg, 0-0.25% Cr, 0-0.2% Zn, 0.02%-0.05% Ti, 0-0.01% B, and the balance being Al.

[0017] Preferably, the first mold in step S2 is concave downward to form a connected cylindrical cavity and a spherical cavity, the inner wall of the cylindrical cavity forms an angle W of 3-5° with the center line of the first mold, and the cylindrical cavity and the spherical cavity are chamfered, and the radius of the chamfer is 3-8 mm. By setting the cylindrical cavity to gradually shrink to the side of the spherical cavity, the blank can be easily demolded during forging, and the chamfer between the two can effectively prevent folding during forming.

[0018] Preferably, the outer diameter of the circle where the cylindrical cavity is located is D1, the spherical center radius corresponding to the spherical cavity is SR1, the height of the corrosion-resistant aluminum alloy spherical crown is H, the spherical center radius is SR, the deformation amount X in step S2 is L / H, and Y is D1 / d, wherein 2.4≤X≤3.0 and 1.5≤Y≤2.3. This setting can control the uniform deformation amount during hot forming and ensure that the internal organization of the formed spherical crown is uniform.

[0019] Preferably, the second mold in step S4 is concave downward to form a connected cylindrical cavity and a spherical cavity, and the cylindrical cavity and the spherical cavity are chamfered, and the radius of the chamfer is 2-4 mm. Preferably, the volume of the inner cavity of the second mold is the same as that of the first mold.

[0020] Preferably, the outer diameter of the circle where the cylindrical cavity is located is D1, the spherical center radius corresponding to the spherical cavity is SR1, and the cold deformation amount Z in step S4 is [1-(D1 / D2) 2 ]×100%.

[0021] Preferably, the cold deformation amount Z is 2%-4%. When the cold deformation amount exceeds 4%, residual stress accumulation in the opposite direction will occur, and cold work hardening or cracking will also occur. When the cold deformation amount is less than 2%, the stress relief effect is not good. By having a corresponding relationship between the inner cavities of the first mold and the second mold, the spherical crown blank as a whole can have the same deformation amount during forging.

[0022] Preferably, the preparation method further comprises: step S6, machining and surface treatment, machining the spherical cap blank into a specified size, rolling the surface with a diamond special tool, the part rotating at 1500-2000 rpm, the machining amount being 0.05-0.08 mm, the surface roughness and profile degree being ≤0.2 μm, and then hard anodizing treatment is performed to improve the surface wear resistance.

[0023] The application further provides a corrosion-resistant aluminum alloy spherical cap prepared by the above method. The application further provides a support comprising a spherical cap lining plate prepared from the above corrosion-resistant aluminum alloy spherical cap. The corrosion-resistant aluminum alloy spherical cap and the support have the same beneficial effects as the above preparation method, which will not be described herein. Preferably, the support is a spherical support.

[0024] Compared with the prior art, the preparation method of the corrosion-resistant aluminum alloy spherical cap has the following beneficial effects: 1) by optimizing the element composition of the aluminum alloy bar, the prepared aluminum alloy spherical cap has high strength, hardness and corrosion resistance, meeting the application safety in marine environments, industrial acidic atmospheric environments and the like; 2) by the sizes of the first die and the second die, the deformation amount of each part of the spherical cap blank is accurately controlled, the grains are uniform, the problems of insufficient metal filling and difficult demolding of the aluminum alloy spherical cap blank in hot die forging are solved, the blank size is accurate, the machining allowance is small, the material utilization rate is improved to more than 70%, and the economic application of the aluminum alloy spherical cap is met; 3) after the solid solution treatment, cold deformation is performed, which can offset the thermal stress and residual stress generated in the solid solution treatment, and improve the size stability of the machined spherical cap. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 FIG. 1 is a structural schematic diagram of an aluminum alloy spherical cap with a single spherical surface in embodiment 1 of the application;

[0026] Figure 2 FIG. 2 is a structural schematic diagram of a first die for hot forming in embodiment 1 of the application;

[0027] Figure 3 FIG. 3 is a structural schematic diagram of a second die for cold forming in embodiment 1 of the application;

[0028] Figure 4 FIG. 4 is a structural schematic diagram of an aluminum alloy spherical cap with a double spherical surface in embodiment 2 of the application;

[0029] Figure 5 FIG. 5 is a structural schematic diagram of a first die for hot forming in embodiment 2 of the application;

[0030] Figure 6 FIG. 6 is a structural schematic diagram of a second die for cold forming in embodiment 2 of the application.

[0031] Reference Signs List

[0032] 1 - upper mold; 2 - lower mold. DETAILED DESCRIPTION

[0033] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings. It should be noted that the technical features in the embodiments of the present application can be combined with each other without conflict.

[0034] The bridge support is an important structural component connecting the upper structure and the lower structure of the bridge, which is usually erected on the pier, fixes the upper structure on the pier, supports the upper structure of the bridge, and reliably transmits the reaction force and deformation of the upper structure to the lower structure of the bridge. The spherical support is widely used in large-span bridges, wide bridges, curved bridges and other complex bridges due to its high bearing capacity, large rotation angle, flexible rotation, and independent rotation torque and rotation angle.

[0035] With the continuous development of China's scientific and technological level, higher requirements are put forward for the span, structure form and function of the bridge structure, and the performance of the spherical crown lining plate as the core component for realizing the bearing, sliding and rotation of the spherical support determines the overall performance and application scenario of the bridge. Therefore, the Chinese patent with application number 201810175197.0 discloses a high-wear-resistant aluminum alloy intermediate plate, which comprises an aluminum alloy base and a hard wear-resistant layer, the hard wear-resistant layer is compounded on the outer surface of the aluminum alloy base, the thickness is 20-100 μm, which can effectively solve the problem of easy scratching on the surface. The Chinese patent with application number 201810131148.7 discloses an aluminum alloy with high wear resistance, a spherical crown prepared therefrom and a preparation method of the spherical crown. The spherical crown is prepared by using a special aluminum alloy, and is produced by a process of casting and then extruding, which can improve the defect of internal porosity caused by casting and has high tensile strength. In order to solve the problems of economy, reliability and corrosion resistance of the aluminum alloy spherical crown, the inventor proposes the following technical scheme:

[0036] Example 1

[0037] A preparation method of an aluminum alloy spherical crown, comprising:

[0038] Step S1, blanking

[0039] The aluminum alloy bar stock is sawed into a segment with a length of 226 mm and a diameter of 210 mm, and the weight percentage of each element in the aluminum alloy bar stock is: 1.05% Si, 0.2% Fe, 0.02% Cu, 0.8% Mn, 1.0% Mg, 0.05% Cr, 0.06% Zn, 0.05% Ti, 0.01% B, and the balance is Al.

[0040] By reasonably matching the elements Si, Mg, Mn, sufficient Mg2Si precipitated phase is maintained in the bar; by adding specific content of elements Ti, B, the organization grain can be further refined, the cracking tendency can be reduced, and the toughness of the material can be further improved; by reducing the content of impurity elements Cu, Fe, Cr, Zn, etc., the material can have excellent exfoliation corrosion resistance.

[0041] Step S2, hot forming

[0042] After the segment material is heated to 460 DEG C and kept for 4h, the first mold is preheated to 230 DEG C and the surface is uniformly coated with lubricating oil, the diameter D1 of the first mold is 448mm, the height H1 is 72mm, the spherical core radius SR1 is 630mm, and the slope W is 3 DEG, as shown in Figure 2 The lubricating oil is composed of 70% cylinder oil + 30% graphite; the segment material is transferred to the first mold, and hot pressing is carried out by using a 2500 ton oil press to make it full of the mold to form, the upsetting ratio R is 3.1, and then it is rapidly water cooled to room temperature. The upsetting ratio refers to the ratio of the height of the blank before upsetting to the height of the blank after upsetting.

[0043] Step S3, solution treatment

[0044] The blank obtained in step S2 is transferred to a resistance furnace and heated to 530 DEG C for 230 min, and then rapidly water cooled to room temperature.

[0045] Step S4, cold deformation

[0046] The blank obtained in step S3 is placed in a second mold, and the specific size of the second mold is: diameter D2 = 456mm, height H2 = 68mm, spherical core radius SR2 = 640mm, as shown in Figure 3 The cold pressing forming is carried out on a 2500 ton oil press to make the mold completely full, and the cold deformation is 3.4%; this step can offset the thermal stress and residual stress generated by solution treatment.

[0047] This step can precisely control the deformation of each part of the solution treated spherical crown blank, eliminate the quenching organization stress of the spherical crown blank, ensure the size precision and stability of the aluminum alloy spherical crown, and the application of friction pair is reliable; the machining allowance can be significantly reduced, the material utilization rate and production efficiency can be improved, and the manufacturing cost can be reduced.

[0048] Step S5, aging

[0049] The blank obtained in step S4 is placed in a resistance furnace and heated to 170 DEG C, and kept for 720 min.

[0050] The diameter D of the aluminum alloy spherical cap blank is 456 mm, the height H is 68 mm, the spherical center radius SR is 640 mm, and the weight is 22 kg, as shown in Figure 1 The transverse mechanical properties are as follows: yield strength R P0.2 = 316 Mpa, tensile strength R m = 326 Mpa, elongation A = 11.5%, and HBW = 112; the longitudinal mechanical properties are as follows: yield strength R P0.2 = 312 Mpa, tensile strength R m = 335 Mpa, elongation A = 12%, and HBW = 110. The transverse and longitudinal properties are basically consistent, the anisotropy of the plate is eliminated, and the uniformity of the structure of the spherical cap blank is improved.

[0051] Step S6, machining and surface treatment

[0052] The blank is machined to have a diameter of 444 mm and a thickness of 57 mm, and the material utilization rate is 70%. A diamond special tool is used, the part rotation speed is 1600 r / min, the machining amount is 0.07 mm, the part surface roughness and profile degree are less than or equal to 0.2 μm, and the surface is rolled to improve the surface wear resistance.

[0053] The sample is soaked in a solution containing 4.0 mol / l of sodium chloride, 0.5 mol / l of potassium nitrate and 0.1 mol / l of nitric acid (pH value is about 0.4) at 25°C for 48 h, and the surface of the sample is checked. It is found that no pitting occurs on the surface, and it is rated as the best corrosion resistance level N according to GB / T22639-2008 "Aluminum Alloy Machining Product Exfoliation Corrosion Test Method". The aluminum alloy spherical cap can be used for the machining and forming of the spherical cap lining plate of the spherical support of the bridge.

[0054] Example 2

[0055] A preparation method of an aluminum alloy spherical cap, comprising:

[0056] Step S1, blanking

[0057] The aluminum alloy bar stock is sawed into a length L of 326 mm and a diameter of 230 mm. The weight percentage of each element in the aluminum alloy bar stock is as follows: 0.88% Si, 0.15% Fe, 0.06% Cu, 0.6% Mn, 0.9% Mg, 0.07% Cr, 0.05% Zn, 0.04% Ti, and 0.008% B, and the balance is Al.

[0058] The specifications of the segment are designed according to the heat deformation amount and the subsequent cold deformation amount control of each part. The elements also contain unavoidable impurities.

[0059] Step S2, hot forming

[0060] The segment material of step S1 is heated to 480℃ and kept for 4h, while the first mold is preheated to 280℃ and then evenly coated with lubricating oil on its surface, the first mold is composed of an upper mold 1 and a lower mold 2, the upper mold 1 and the lower mold 2 are arranged symmetrically, the inner cavity size of the upper mold 1 is: diameter D1 is 406mm, height H1 is 62mm, spherical core radius SR1 is 500mm, slope W is 4°, as shown in Figure 5 The lubricating oil is composed of 70% cylinder oil + 30% graphite; hot pressing is carried out by using a 2500-ton oil press to make it full of the first mold for forming, and the diameter of the blank is 406mm, the thickness is 124mm, the upsetting ratio R=2.6, then it is quickly water cooled to room temperature.

[0061] Step S3, solution treatment

[0062] The blank obtained in step S2 is placed in a resistance furnace and heated to 550℃ and kept for 380min, so that the temperature of the blank is homogenized, and then it is quickly water cooled to room temperature.

[0063] Step S4, cold deformation

[0064] The blank obtained in step S3 is placed in a second mold, the second mold is composed of an upper mold 1 and a lower mold 2, the upper mold 1 and the lower mold 2 are arranged symmetrically, the inner cavity size of the upper mold 1 is: diameter D2 is 412mm, height H2 is 59mm, spherical core radius SR2 is 505mm, as shown in Figure 6 Cold pressing forming is carried out on a 2500-ton oil press to make the mold completely full, forming a blank with a diameter of 412mm, a thickness of 118mm, and a cold deformation of 2.8%. This step can offset the thermal stress and residual stress generated by solution treatment.

[0065] Step S5, aging

[0066] The blank obtained in step S4 is placed in a resistance furnace and heated to 180℃ and kept for 600min.

[0067] The finally obtained aluminum alloy spherical crown blank has a diameter D of 400mm, a height H of 108mm, a spherical core radius SR of 500mm, and a weight of 38kg, as shown in Figure 4 The transverse mechanical properties of the blank are: yield strength RP0.2=285Mpa, tensile strength Rm=316Mpa, elongation A=13%, HBW=108; the longitudinal mechanical properties are: yield strength RP0.2=290Mpa, tensile strength Rm=320Mpa, elongation A=12.5%, HBW=105, the transverse and longitudinal properties are basically the same, eliminating the anisotropy of the plate and improving the uniformity of the microstructure of the spherical crown blank.

[0068] Step S6, machining and surface treatment

[0069] The blank is machined into a diameter of 400mm and a thickness of 108mm, and the material utilization rate is 75%; the surface is rolled by using a diamond special cutter, the part rotation speed is 1800r / min, the machining amount is 0.08mm, the part surface roughness and profile degree are less than or equal to 0.2um, the surface is rolled and strengthened, and then the hard anodic oxidation treatment is carried out, so that the surface wear resistance is improved.

[0070] The sample is soaked in a solution containing 4.0mol / L of sodium chloride, 0.5mol / L of potassium nitrate and 0.1mol / L of nitric acid (pH value is about 0.4) at 25 DEG C for 48h, and the sample surface is checked; no pitting corrosion occurs on the surface, according to GB / T22639-2008 "Aluminum Alloy Machining Product Exfoliation Corrosion Test Method"

[0071] The evaluation is the best corrosion resistance level N level, and the aluminum alloy spherical crown can be used for the machining and forming of the spherical crown lining plate of a bridge hyperboloidal spherical type shock isolation support.

[0072] The manufacturing method of the aluminum alloy spherical crown can also be used for the machining and forming of the aluminum alloy spherical crown in various bridge supports such as cylindrical surface steel supports, cylindrical shock isolation supports and friction pendulum supports, and the machining and forming of various support plates made of aluminum alloy in the bridge supports, so that the support weight is further reduced, and the size stability, corrosion resistance, durability and economic performance are good.

[0073] Although the present application is disclosed as above, the present application is not limited to this. Any person skilled in the art, without departing from the spirit and scope of the present application, can make various changes and modifications, therefore the protection scope of the present application should be limited by the scope defined by the claims.

Claims

1. A method of making a corrosion resistant aluminum alloy dome, characterized by, The application relates to a preparation method of a corrosion-resistant aluminum alloy spherical crown. S1, blanking, cutting an aluminum alloy bar into a segment with a diameter of d and a length of L, ensuring that the weight of the segment is consistent with that of a spherical crown blank; S2, hot forming, heating the segment obtained in step S1 to 470-510 DEG C and keeping the temperature, preheating a first mold to 200-300 DEG C and uniformly applying lubricating oil on the surface of the first mold; transferring the segment into the first mold for hot pressing to make the segment fill the mold for forming, the upsetting ratio R is greater than or equal to 2.4, and then the segment is rapidly water-cooled to room temperature; S3, solid solution treatment, keeping the blank obtained in step S2 at 450-560 DEG C for 150-350 min, and then rapidly water-cooling the blank to room temperature; S4, cold deformation, putting the blank obtained in S3 into a second mold to make the blank completely fill the second mold for cold pressing forming, wherein the cold deformation amount is 2-4%; S5, aging, keeping the blank obtained in step S4 at 160-190 DEG C for at least 480 min; In step S1, the element composition of the aluminum alloy bar is as follows: 0.4-1.1% of Si, 0-0.5% of Fe, 0-0.1% of Cu, 0.5-0.9% of Mn, 0.5-1.1% of Mg, 0-0.25% of Cr, 0-0.2% of Zn, 0.02-0.05% of Ti and 0-0.01% of B, and the balance is Al; In step S2, the first mold is downwardly recessed to form a connected cylindrical inner cavity and a spherical segment inner cavity, the inner wall surface of the cylindrical inner cavity forms an included angle W of 3-5 DEG with the center line of the first mold, and the cylindrical inner cavity and the spherical segment inner cavity are arranged with a fillet, and the radius of the fillet is 3-8 mm; The outer diameter of the circle where the cylindrical inner cavity of the first mold is located is D1, the spherical center radius corresponding to the spherical segment inner cavity of the first mold is SR1, the height of the corrosion-resistant aluminum alloy spherical crown is H, the spherical center radius is SR, the deformation amount X in step S2 is L / H and Y is D1 / d, and 2.4<=X<=3.0 and 1.5<=Y<=2.

3.

2. The method of claim 1, wherein the corrosion resistant aluminum alloy dome is prepared by the steps of: In step S4, the second mold is downwardly recessed to form a connected cylindrical inner cavity and a spherical segment inner cavity, and the cylindrical inner cavity and the spherical segment inner cavity are arranged with a fillet, and the radius of the fillet is 2-4 mm.

3. The method of making a corrosion resistant aluminum alloy globoid according to claim 2, wherein, The second mold is concave downward to form a circle with a cylindrical inner cavity, the outer diameter of the circle is D2, the second mold is concave downward to form a spherical inner cavity corresponding to the spherical center radius SR2, and the cold deformation amount Z in step S4 is [1-(D1 / D2) 2 ]×100%.

4. The method of making a corrosion resistant aluminum alloy globoid according to claim 3, wherein The value of the cold deformation amount Z is 2-4%.

5. The method of making a corrosion resistant aluminum alloy globocap of claim 1, wherein, The preparation method further comprises: step S6, machining and surface treatment, machining the spherical crown blank into a specified size, rolling the surface by using a diamond special cutter, the rotating speed of the part is 1500-2000 rpm, the machining amount is 0.05-0.08 mm, the surface roughness and the profile degree are less than or equal to 0.2 microns, and then hard anodic oxidation treatment is carried out.

6. A corrosion resistant aluminum alloy dome characterized by, The method is prepared by any one of claims 1-5.

7. A support characterized by, The spherical crown liner plate is prepared from the corrosion-resistant aluminum alloy spherical crown in claim 6.

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