A kind of medium and high strength aluminum alloy seamless pipe extrusion process method

Abstract

The invention relates to an extrusion process method for a middle-high-strength aluminum alloy seamless tube, and belongs to the field of aluminum alloy extrusion. The extrusion process method comprises the following steps of: heating middle-high-strength aluminum alloy bar billet to a thermal extrusion temperature; preheating an extrusion barrel to a temperature of 400-450 DEG C; preheating a mould to a temperature of 400-500 DEG C; assembling a preheated punching head on an extrusion pad, assembling the bar billet and the extrusion pad into the extrusion barrel in sequence, heading the bar billet to fill the extrusion barrel, pushing the punching head to realize bar billet punching through an extrusion needle, and pushing the punching head to a position outside a sizing belt of an extrusion mould; and after punching is completed, enabling the extrusion needle and an extrusion shaft to follow up to complete extruding operation, and controlling extrusion speed to be 1.0-5 mm / s. High-strength seamless tube blank manufactured by the method is free of defects such as air bubbles and surface scratches in inner and outer surfaces, has wall thickness precision higher than international standards, uniform internal structure distribution and good mechanical property, can simplify a follow-up processing process, improves production efficiency and reduces production cost, and has obvious economic benefits.

Description

technical field [0001] The invention relates to an extrusion process method of a medium-high strength aluminum alloy seamless pipe, which belongs to the field of aluminum alloy extrusion. Background technique [0002] Aluminum alloy seamless pipe extrusion usually adopts two methods: solid ingot piercing extrusion and hollow ingot extrusion. Among them, the wall thickness eccentricity of piercing extrusion is small and the surface quality is high. However, due to the high deformation resistance of medium and high-strength aluminum alloys. In the prior art, when producing medium and high strength aluminum alloy seamless pipes, only the hollow ingot lubrication extrusion method can be used, which easily leads to a series of problems such as extrusion eccentricity and inner surface scratches. Therefore, at present, there are usually problems such as large wall thickness deviation and many internal and external surface defects in the extrusion of medium and high-strength aluminu...

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Problems solved by technology

[0002] Aluminum alloy seamless pipe extrusion usually adopts two methods: solid ingot piercing extrusion and hollow ingot extrusion. Among them, the wall thickness eccentricity of piercing extrusion is small and the surface quality is high. However, due to the characteristics of high deformation resistance of medium and high-strength aluminum alloys

In the prior art, when producing medium and high strength aluminum alloy seamless pipes, only the hollow ingot lubrication extrusion method can be used, which easily leads to a series of problems such as extrusion eccentricity and inner surface scratches

Therefore, at present, there are usually problems such as large wall thickness deviation and many internal and external surface defects in the extrusion of medium and high-strength aluminum alloy tube blanks, which requires a large number of surface defect treatment work before subsequent drawing and rolling processing, which reduces production efficiency and success rate, resulting in the failure of finished products. Dimensional accuracy is difficult to guarantee

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