Production process of 7021 aluminum alloy seamless tube

Abstract

The invention belongs to the technical field of aluminum alloy manufacturing, and relates to a production process of a 7021 aluminum alloy seamless tube. Aluminum alloy raw materials are prepared according to the weight percentage, namely, less than or equal to 0.12% of Si, less than or equal to 0.2% of Fe, 0.1-0.2% of Cu, less than or equal to 0.05% of Mn, 1.2-1.6% of Mg, less than or equal to 0.02% of Cr, 5.2-5.5% of Zn, less than or equal to 0.02% of Ti, 0.1-0.15% of Zr, less than or equal to 0.05% of single impurity, less than or equal to 0.15% in total, and the balance Al. The aluminum alloy raw materials are subjected to casting, homogenization, concentricity adjustment, extrusion, sawing and heat treatment processes to be matched with a formula, and the 7021 aluminum alloy seamlesstube with the performance meeting the requirements is successfully extruded.

Description

technical field [0001] The invention belongs to the technical field of aluminum alloy manufacturing and relates to a production process of a 7021 aluminum alloy seamless pipe. Background technique [0002] Horizontal double-action extrusion machine Forward extrusion of seamless pipe is one of the most commonly used production methods for aluminum alloy pipes. As the main variety of pipe products, seamless pipes can be extruded with hollow ingots without needles. [0003] The horizontal extrusion method has many advantages, such as extruding large-scale pipes; all mechanisms can be arranged on the same level, which is easy to realize mechanization and automation; horizontal discharge, long billets can be used to extrude long pipes, etc., but there are also Certain disadvantages, because the weight of each component is added to the guide sleeve and horizontal guide rail surface, it is easy to wear or some components are thermally expanded to cause center imbalance, pipe eccent...

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Problems solved by technology

[0003] The horizontal extrusion method has many advantages, such as extruding large-scale pipes; all mechanisms can be arranged on the same level, which is easy to realize mechanization and automation; horizontal discharge, long billets can be used to extrude long pipes, etc., but there are also Certain disadvantages, because the weight of each component is added to the guide sleeve and horizontal guide rail surface, it is easy to wear or some components are thermally expanded to cause center imbalance, pipe eccentricity, etc. Therefore, horizontal adjustment of pipe concentricity is necessary for extruding seamless pipes. One of the essential steps

[0004] In the production process, double-action follower needle extrusion is often used. At present, there are few studies on extruding 7021 alloy seamless pipes. It is difficult to control the process in the actual preparation process. During the extrusion process, the metal flow friction is large, and it is easy to Broken needle accident

If the process is not proper, it will easily cause excessive pressure and excessive aluminum sticking on the needle tip of the needle bar, which will lead to defects such as failure to extrude the finished product or scratches on the inner wall of the finished product.

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