Production method of ultra-large-diameter thin-walled pressure-resistant aluminum alloy pipe

Abstract

The invention discloses a production method of an ultra-large-diameter thin-walled pressure-resistant aluminum alloy pipe. The production method comprises the steps: (1) feeding, (2) winding or rolling of a reel, (3) performing stirring friction welding, (4) performing solid solution quenching, (5) reshaping, (6) performing aging treatment, and (7) performing pressure resistance test. The aluminum alloy pipe produced by using the method is high in welding seam strength, high in welding seam consistency, high in pipeline roundness and high in internal pipe pressure resistance. According to each series of typical alloys subjected to the method and the process, the minimum yield strength of a pipe welding seam and the allowable internal pipe pressure resistance (applicable to gas and liquid) are as follows: (1) if the alloy is 2XXX, sigma <0.2> is greater than or equal to 290 Mpa, and P (internal pressure) is greater than or equal to 15 Mpa; (2) if the alloy is 6XXX, sigma<0.2> is greater than or equal to 200 Mpa, and P (internal pressure) is greater than or equal to 10 Mpa; (3) if the alloy is 7XXX, sigma<0.2> is greater than or equal to 395 Mpa, and P (internal pressure) is greater than or equal to 20 Mpa.

Description

technical field [0001] The invention relates to the field of non-ferrous metal processing, and provides a production method of a high-strength aluminum alloy thin-walled pressure-resistant pipe with a diameter exceeding Φ800 mm. technical background: [0002] The production methods of aluminum alloy pipes are usually extrusion, spinning, etc. Extrusion is limited by extrusion efficiency, extrusion ratio and extrusion equipment. At present, the wall thickness that can be extruded in the world is 10-50mm and the maximum diameter is No more than Φ700mm. Spinning can increase the diameter of extruded tubes, but the length that can be processed is limited and the efficiency is relatively low. Therefore, it is not suitable for mass production of thin-walled tubes. At present, large-diameter thin-walled steel pipes are often produced by welding. Due to the good fusion welding performance of steel, especially low-carbon steel, the fusion welding performance is good, and high-qualit...

AI Technical Summary

Problems solved by technology

However, the fusion welding performance of aluminum alloys is poor, especially high-strength aluminum alloys usually have high alloy content, and their fusion welding performance is even worse, especially when the welding thickness exceeds about 20mm, it is difficult to obtain high-quality welds by fusion welding. And the welding coefficient of the weld performance is usually only below 0.5-0.6, especially when the weld is long, it is more difficult to obtain a weld with consistent quality and stable performance. Therefore, there must be a welding method with high reliability to ensure high strength. The weldability of the aluminum alloy and the consistency of the welding performance of the long weld, friction stir welding can just solve this problem, the weld structure is dense, the grain is fine, the quality is stable during long-distance welding, and the welding coefficient can reach 0.8~ It is about 0.9, which is the most suitable welding method for aluminum alloys with a certain welding thickness. With reasonable production technology and heat treatment, high-strength and high-pressure resistant aluminum alloy pipes can be produced.

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