6.This technology belongs to the field of aluminum alloy manufacturing technology, relates to a 7021 aluminum alloy seamless tube production process, aluminum alloy raw materials in accordance with the weight percentage of ingredients, namely: Si≤ 0.12%, Fe≤ 0.2%, Cu: 0.1 ~ 0.2%, Mn≤ 0.05%, Mg: 1.2 ~ 1.6%, Cr≤ 0.02%, Zn: 5.2 ~ 5.5%, Ti≤ 0.02%, Zr: 0.1 ~ 0.15%, single impurity ≤ 0.05%, total ≤ 0.15%, allowance for Al, aluminum alloy raw material after casting, homogenization, concentricity adjustment, extrusion, sawing and heat treatment process with the formula, successfully extruded performance to meet the requirements of 7021 alloy seamless tube.

7.This technology provides a seamless aluminum alloy pipe production process for aerospace, involving the technical field of aluminum alloy production, composition and weight ratio are: Zn8.0-8.5%, Mg2.5-2.8%, Cu2.0-2.3%, ZR0.1-0.15%, Be0.002%,Fe0.25 %,Si0.08 %,Mn0.05 %,Cr0.02 %,Ti0.03 %, residual Al. The aerospace seamless aluminum alloy pipe production process includes step S1 melting, step S2 refining the alloy melt, step S3 homogenizing heat treatment, step S4 extrusion, and step S5 heat treatment. The seamless aluminum alloy pipe produced by this technology has high strength, good corrosion resistance, no cracks on the surface, no cracks, pores, oxide film, loose casting defects in the low-power structure, and no coarse recrystallization structure and overburning in the microstructure, which meets the production requirements.

8.This technology relates to an extrusion method of high-precision aluminum alloy thin-wall seamless tube used in nuclear industry, including the following steps: (1) batching: according to the composition ratio of batching, must use more than 99.99% of high purity aluminum; (2) semi-continuous casting: semi-continuous casting after smelting, refining and online slag removal and gas removal of the raw material; (3) homogenization heat treatment: the ingot, 510 ~ 580°C heat preservation 6 12 hours homogenization heat treatment; (4) extrusion: heated to 450℃ in the extrusion machine, to 5 15mm/s extrusion speed to obtain aluminum alloy precision in ±10%, internal and external surface roughness ≤3.2μm pipe; (5) Pull straightening: the pipe with the thickness of the finished product is straightened and trimmed to get the pipe that meets the requirements of drawing production; (6) drawing: the above obtained pipe after the head, lubrication after drawing to obtain a precision of ±3% aluminum alloy pipe, and meet the internal and external surface roughness ≤1.6μm. To improve the tensile strength, yield strength and elongation of aluminum alloy pipe.

9.This technology provides a seamless aluminum alloy tube without clearance extrusion method, the extrusion method in the extrusion tube lining of the entrance section is processed into a cone flaring, and the flaring section of the extrusion section inward diameter is slightly smaller than the extrusion ingot diameter. Innovation point of this technology is mainly adopted outside diameter slightly larger than extrusion cylinder liner inside the crowded YaDing billet, in order to push the crowded YaDing smoothly into the container, the container liner inlet end processed into cone “bell”, at the start of the extrusion, by extrusion rod and dummy block a certain pressure, heating after crowded YaDing billet from taper entry into the container until the bottom. Because the outer diameter of the extrusion ingot is slightly larger than the inner diameter of the extrusion cylinder, the extrusion ingot will have a certain plastic deformation in the process of pushing, and all the air in the extrusion cylinder will be extruded, and the extrusion cylinder will be completely filled, without leaving any gap. Therefore, there is no need for upsetting extruding, directly perforation and extrusion forming.

10.This technology provides a kind of high strength aluminum alloy seamless pipe, which is characterized in that: by mass %, the aluminum alloy contains Si: 0.7 ~ 0.9%, Cu: 1.2 ~ 1.8%, Mg: 0.8 ~ 1.2%, the rest is Al and inevitable impurities. The aluminum alloy of this technology has the advantages of high strength, easy plastic processing, easy straightening after solution water quenching to reach precise size, corrosion resistance and scratch avoidance, so as to greatly improve the practicability of this technology.