A kind of al-mg-si aluminum alloy bar and heat treatment method thereof

Abstract

The invention provides an Al-Mg-Si aluminum alloy rod and a heat treatment method thereof. The heat treatment method comprises the following steps: placing the aluminum alloy rod in a homogeneous furnace, raising the temperature of the furnace to the homogenization temperature T1, and dissolving the aluminum Alloy rods are kept at T1 temperature for one time, and the duration of the first time is t1; the aluminum alloy rods are cooled to the solid solution temperature T2 with the homogenization furnace, and the heat preservation time is t2; 3S transfer the aluminum alloy rods from the homogenization furnace Come out, cool the aluminum alloy bar to room temperature at a predetermined cooling rate; 4S stretches the cooled aluminum alloy bar to maintain the tensile deformation of the aluminum alloy bar at 1-3%; 5S stretches the aluminum alloy bar after stretching The bar is placed in an environment of aging treatment temperature T3 for three times of heat preservation, and the duration of the three times of heat preservation is t3. The heat treatment method of the present application can achieve the dual effects of homogenization and quenching through one heat treatment, and the process is greatly optimized, which saves resources, reduces production costs, and improves production efficiency.

Description

technical field [0001] The invention belongs to the field of non-ferrous metals, and particularly relates to a heat treatment method for an Al-Mg-Si alloy rod. Background technique [0002] Al-Mg-Si alloys have high specific strength, high toughness, good processability and excellent corrosion resistance, and are widely used in aerospace, rail transit, automobiles, and civil buildings. Heat treatment is a necessary step before the aluminum alloy is put into use, which mainly includes homogenization treatment, solution treatment (quenching) and aging treatment. Al-Mg-Si alloy materials usually used for machining are extruded after homogenization of rods, and then quenched online or offline to obtain supersaturated solid solutions, and then aged to improve product strength. However, the bars produced by this method are mostly fibrous crystal structures. During machining, it is difficult to break chips, easily entangled with knives, and the products are anisotropic, which is l...

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Problems solved by technology

However, the rods produced by this method are mostly fibrous crystal structure. During the machining process, it is difficult to break chips, easy to wrap the knife, and the products are anisotropic, which limits the products that require isotropy.

Although it is possible to produce a recrystallized structure by controlling the extrusion process during the extrusion process, the structure is not uniform and the production is difficult; When it is small, it is easy to shake the knife and the surface quality of the bar is poor

[0003] In addition, before the bar is rolled, it is often necessary to homogenize the bar and then perform offline quenching. The two heat treatments are carried out independently one after another. The whole process requires multiple liftings, and the offline quenching furnace consumes a lot of energy and costs a lot. , low production efficiency

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