阅读说明：本技术 一种高强度6系铝合金及其制备方法和应用 (High-strength 6-series aluminum alloy and preparation method and application thereof ) 是由 金龙兵 于 2020-07-21 设计创作，主要内容包括：一种高强度6系铝合金及其制备方法和应用,涉及一种铝合金、制备方法和应用。本发明针对现有技术存在的上述不足,提出高强度6系铝合金含有Si：0.9～1.8％,Fe：0～0.5％,Cu：0.35～1.2％,Mn：0.2～1.2％,Mg：0.8～1.6％,Zn：0～0.5％,还含Cr、Zr或Ti。制备方法：熔炼和铸造得到铸锭,均匀化退火,锯切和挤压,淬火,人工时效。高强度6系铝合金用于制造抱杆和高压开关液压弹簧操动机构部件。本发明铝合金兼顾耐蚀性和强度。力学性能达到甚至优于2A12合金和2A50合金,导电性好,成本较2A12、2A50等2系铝合金低。本发明适用于高强度6系铝合金的制备和应用。(A high-strength 6-series aluminum alloy and a preparation method and application thereof relate to an aluminum alloy and a preparation method and application thereof. In order to overcome the defects in the prior art, the invention provides a high-strength 6-series aluminum alloy containing Si: 0.9-1.8%, Fe: 0-0.5%, Cu: 0.35-1.2%, Mn: 0.2-1.2%, Mg: 0.8-1.6%, Zn: 0-0.5%, and further contains Cr, Zr or Ti. The preparation method comprises the following steps: smelting and casting to obtain cast ingot, homogenizing annealing, sawing, extruding, quenching and artificial ageing. The high-strength 6-series aluminum alloy is used for manufacturing the holding pole and the high-voltage switch hydraulic spring operating mechanism component. The aluminum alloy of the invention has both corrosion resistance and strength. The mechanical property is even better than 2A12 alloy and 2A50 alloy, the conductivity is good, and the cost is lower than 2 series aluminum alloy such as 2A12, 2A50 and the like. The invention is suitable for the preparation and application of the high-strength 6-series aluminum alloy.)

1. A high-strength 6-series aluminum alloy is characterized in that: the high-strength 6-series aluminum alloy contains Si: 0.9-1.8%, Fe: 0-0.5%, Cu: 0.35-1.2%, Mn: 0.2-1.2%, Mg: 0.8-1.6%, Zn: 0-0.5%, and further comprises at least one of Cr, Zr and Ti, wherein Cr: 0-0.8%, Zr: 0-0.8%, Ti: 0-0.5%, and the balance of Al and inevitable impurities, wherein the total mass percentage of all the inevitable impurities is less than 0.15%, and the mass percentage of single inevitable impurities is less than 0.05%.

2. The high strength 6-series aluminum alloy according to claim 1, wherein: the mass ratio of Mg to Si is less than 1.5.

3. The method of producing a high-strength 6-series aluminum alloy according to claim 1, wherein: the method comprises the following steps:

weighing raw materials according to the mass percentage of each element of the high-strength 6-series aluminum alloy, and smelting and casting the weighed raw materials to obtain an ingot;

secondly, homogenizing and annealing of the ingot:

the homogenizing annealing process comprises the following steps: preserving the heat for 8-16h at 540-570 ℃;

thirdly, sawing and extruding the cast ingot to obtain an extruded material;

the extrusion temperature in the extrusion process is 480-530 ℃;

fourthly, quenching the extruded material obtained in the third step;

fifthly, carrying out artificial aging treatment on the extruded material treated in the step four;

the artificial aging process comprises the following steps: heating to 150-180 ℃, preserving heat for 6-12 h, and finally air cooling.

4. The method for producing a high-strength 6-series aluminum alloy according to claim 1, wherein: and step two, the cooling process after the extrusion material homogenizing annealing is as follows: air cooling for 30min, fog cooling for 30min, and water cooling.

5. The method for producing a high-strength 6-series aluminum alloy according to claim 1, wherein: and step three, the extrusion speed in the extrusion process is less than or equal to 3 m/min.

6. The method for producing a high-strength 6-series aluminum alloy according to claim 1, wherein: and step four, the quenching process is online water quenching or offline quenching.

7. The method of producing a high-strength 6-series aluminum alloy according to claim 6, wherein: the cooling rate is more than 70 ℃/min during the online water quenching; the off-line quenching process comprises the following steps: preserving the heat for 1-3 h at 530-570 ℃, finally cooling with water, and the quenching transfer time is less than or equal to 20 seconds.

8. Use of a high strength 6 series aluminium alloy prepared by the method according to any one of claims 3 to 7, wherein: the high-strength 6 series aluminum alloy is used for manufacturing the holding pole.

9. Use of a high strength 6 series aluminium alloy prepared by the method according to any one of claims 3 to 7, wherein: the high-strength 6 series aluminum alloy is used for manufacturing the components of the hydraulic spring operating mechanism of the high-voltage switch.

Technical Field

The invention relates to an aluminum alloy and a preparation method and application thereof.

Background

The holding pole is used as a professional construction tool for electric power construction, is mainly applied to the construction of a transmission line assembly pole tower and the construction of stringing crossing, and the metal holding pole used at present mainly comprises two materials, namely a steel holding pole and an aluminum holding pole, wherein the aluminum holding pole has the characteristic of portability, is more and more widely applied, and especially can exert the superiority under the mountainous terrain condition. The aluminum holding pole mainly has two forms, one is a lattice holding pole formed by assembling main materials and auxiliary materials by aluminum alloy angle materials, and the other is a tubular holding pole formed by assembling aluminum alloy pipes. At present, aluminum alloy angle aluminum sections and pipes of 2A 12T 4 are adopted in the industry for manufacturing the aluminum holding pole. The 2A12 is a 2-series aluminum alloy, has medium strength and is mainly used for bearing structural members, but because the 2A12 aluminum alloy has high content of Cu and poor corrosion resistance, the 2A12 section bar and the pipe used for manufacturing the aluminum holding pole need to be subjected to anodic oxidation treatment, and an oxide film is formed on the surface of the section bar and the pipe to achieve the effect of corrosion resistance. Because the 2A12 alloy belongs to hard alloy, the processing and manufacturing cost is relatively high, and in addition, the anodic oxidation surface treatment is required, which has certain influence on environmental protection.

In addition, according to the article of corrosion resistance and protection of the aluminum alloy holding pole published in the journal of Guangxi electric power engineering in 2000 Guo scholar, the service life of the aluminum alloy holding pole is greatly shortened due to the corrosion problem, and meanwhile, certain potential safety risks exist. Although the surface of the 2A12 alloy is subjected to anodic oxidation treatment, the machined section is not protected by an oxide film along with subsequent procedures of drilling, riveting, sawing and the like, and is exposed in outdoor severe conditions, stress corrosion cracking is easily caused, and great potential safety hazards exist. Under the background, a high-strength corrosion-resistant 6-series aluminum alloy material is developed to replace the currently applied 2A12 aluminum alloy material to manufacture the aluminum holding pole, so that the price is obviously reduced while the application is met, and the anode oxidation process and the environmental pollution are reduced due to good corrosion resistance.

In an electric power system, an aluminum alloy material is widely applied as an excellent material with high conductivity and high specific strength, and a 2-series aluminum alloy has higher strength and is more applied to some important force bearing structural parts. The main cylinder body, the energy storage module (energy storage piston cylinder) and other parts in the hydraulic spring operating mechanism in the field of high-voltage switches generally use 2A50 alloy due to large bearing capacity, but because the parts are more critical, the performance requirement on materials is higher, and 2 series aluminum alloy has obvious stress corrosion tendency due to narrow process parameter selection range in the preparation process, so that the performance stability of products in the batch production process is poor, and customers also urgently need to seek a high-strength material with good performance stability and corrosion resistance for replacement.

The 6 series aluminum alloy is an aluminum alloy which takes magnesium and silicon as main alloy elements and takes an Mg2Si phase as a strengthening phase, and belongs to a heat treatment strengthenable aluminum alloy. The alloy has the advantages of moderate strength, high corrosion resistance, no stress corrosion cracking tendency, good welding performance, unchanged corrosion performance of a welding area, good formability and technological performance and the like, is widely applied to the fields of buildings, rail transit, automobiles, communication and the like, and is also a series of materials which are most widely applied in the field of aluminum processing at present. The 6 series aluminum alloy is most widely applied at present and mainly comprises 6061, 6063, 6005A, 6082 and the like, wherein the strength of an extruded material of 6082T6 can reach 380MPa, the yield strength is 320MPa, and the Brinell hardness is 90 HB; the strength of the 2A 12T 4 extrusion material for manufacturing the aluminum holding pole and the strength of the 2A 50T 6 extrusion material for manufacturing the high-voltage switch operating mechanism component need to reach 420-450 MPa, the yield strength is 360-380 MPa, the Brinell hardness is 110HB, and the conventional 6 series aluminum alloy material has a larger difference from the 2 series aluminum alloy in strength and cannot be replaced.

The patent with the publication number of CN103484736B discloses an ultra-high-strength 6000 series aluminum alloy and a preparation method thereof, wherein the tensile strength of the alloy prepared by the patent reaches 500-520 MPa, the yield strength reaches 460-503 MPa, but the alloy is poor in corrosion resistance and low in conductivity, and cannot be applied to manufacturing of holding rods or hydraulic spring operating mechanism components.

Disclosure of Invention

The invention aims to solve the defects in the prior art and provides a high-strength 6-series aluminum alloy and a preparation method and application thereof.

The high-strength 6-series aluminum alloy contains Si in percentage by mass: 0.9-1.8%, Fe: 0-0.5%, Cu: 0.35-1.2%, Mn: 0.2-1.2%, Mg: 0.8-1.6%, Zn: 0-0.5%, and further comprises at least one of Cr, Zr and Ti, wherein Cr: 0-0.8%, Zr: 0-0.8%, Ti: 0-0.5%, and the balance of Al and inevitable impurities, wherein the total mass percentage of all the inevitable impurities is less than 0.15%, and the mass percentage of single inevitable impurities is less than 0.05%.

The preparation method of the high-strength 6-series aluminum alloy comprises the following steps:

weighing raw materials according to the mass percentage of each element of the high-strength 6-series aluminum alloy, and smelting and casting the weighed raw materials to obtain an ingot;

secondly, homogenizing and annealing of the ingot:

the homogenizing annealing process comprises the following steps: preserving the heat for 8-16h at 540-570 ℃;

thirdly, sawing and extruding the cast ingot to obtain an extruded material;

the extrusion temperature in the extrusion process is 480-530 ℃;

fourthly, quenching the extruded material obtained in the third step;

fifthly, carrying out artificial aging treatment on the extruded material treated in the step four;

the artificial aging process comprises the following steps: heating to 150-180 ℃, preserving heat for 6-12 h, and finally air cooling.

The high-strength 6 series aluminum alloy prepared by the method is applied to the manufacturing of the holding pole.

The manufacturing method of the holding pole comprises the following steps: extruding and forming the high-strength 6-series aluminum alloy to obtain an extruded material; assembling and connecting the extruded materials to obtain a holding pole; the extruded material is an extruded section or an extruded pipe; the extruded section is an angle section.

The high-strength 6-series aluminum alloy prepared by the method is applied to the manufacturing of the high-voltage switch hydraulic spring operating mechanism component;

the high-voltage switch hydraulic spring operating mechanism component is a working cylinder or an energy storage piston cylinder, and the manufacturing method comprises the following steps: extruding and forming the high-strength 6-series aluminum alloy to obtain an extruded material; machining the extruded material to obtain a working cylinder or an energy storage piston cylinder in a hydraulic spring energy storage operating mechanism in the high-pressure switch; the extruded material is a round bar or a rectangular bar.

The invention has the beneficial effects that:

according to the invention, through reasonable proportioning of alloy elements, around a specific precipitation sequence, sufficient nano-scale strengthening phase dispersion precipitation is promoted and induced at different stages of aging, and the strength of the material is improved to the maximum extent on the basis of considering corrosion resistance.

The invention adopts high-strength corrosion-resistant 6-series aluminum alloy extrusion materials to prepare the aluminum holding rod and the high-voltage switch hydraulic spring operating mechanism component, and the aluminum holding rod and the high-voltage switch hydraulic spring operating mechanism component comprise extrusion sectional materials, extrusion bar materials and extrusion pipe materials; and the processing technology of the novel high-strength corrosion-resistant 6-series aluminum alloy extruded material is matched, and all mechanical properties of the obtained extruded material reach or are even superior to the levels of 2A12 alloy and 2A50 alloy. The tensile strength is 420-480 MPa, the yield strength is 380-430 MPa, the elongation is 10-16%, the Brinell hardness is 120-140 HB, the conductivity is 37-43% IACS, the product is subjected to neutral salt spray test 540h according to GB/T10125-; compared with 2A12 alloy, the method saves the anode oxidation treatment process and reduces the environmental pollution; and the manufacturing cost is lower than that of the 2A12 alloy by more than 10 percent, and the alloy can completely replace 2A12 to be applied to the manufacturing of the aluminum holding pole. Compared with the 2A50 alloy, the high-strength corrosion-resistant 6-series aluminum alloy material has the advantages of good corrosion resistance and conductivity, good performance stability and cost lower than that of the 2A50 alloy by more than 10 percent.

Patent CN107614718A discloses a method for preparing a high-strength aluminum alloy hot forged material with high tensile strength and high yield strength, wherein forging and artificial aging treatment are repeatedly performed to control the average grain size and orientation difference of grains in the structure, which is the most core technology for realizing high strength. The high strength is finally realized, the tensile strength of the forging is more than or equal to 420MPa, the yield strength is more than or equal to 400MPa, and the elongation is more than or equal to 12%. The invention aims at the process technology of the aluminum alloy extruded material development, realizes the purpose of high corrosion resistance and strength of the aluminum alloy extruded material under the condition of no repeated processing deformation and artificial aging treatment, has simple working procedures, obviously improves the working efficiency, effectively reduces the production cost,

Detailed Description

The technical scheme of the invention is not limited to the specific embodiments listed below, and any reasonable combination of the specific embodiments is included.