Split-flow extrusion process for aluminum alloy 3003 thin-walled parts

Abstract

This invention relates to the field of aluminum alloy extrusion technology, and particularly to a split extrusion process for thin-walled aluminum alloy 3003. The invention involves sequentially subjecting an ingot to integrated homogenization annealing and preheating, die heating, extrusion cylinder heating, and split extrusion treatment, resulting in a split extruded aluminum alloy 3003 thin-walled part. The chemical composition of the ingot (mass percentage) is as follows: Si: 0.05–0.1%, Fe: 0.3–0.4%, Cu: 0.05–0.1%, Mn: 1.05–1.1%, Mg: 0.008–0.01%, Zr: 0.004–0.005%, Cr: 0.004–0.005%, Ni: 0.004–0.005%, Zn: 0.008–0.01%, Ti: 0.02–0.025%, Ce: 0.04–0.05%, with individual impurities ≤0.025%, total impurities ≤0.15%, and the remainder being Al. This method can shorten the heating time of split extrusion of thin-walled aluminum alloy 3003 parts, improve production efficiency, and obtain higher dimensional accuracy and uniform grain size by controlling billet temperature, deformation temperature and deformation speed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum alloy extrusion process, in particular to an aluminum alloy 3003 thin-walled part split-flow extrusion process. BACKGROUND

[0002] 3XXX series aluminum alloy is a non-heat treatment strengthening type aluminum alloy commonly used in Al-Mn series alloy. It has high strength, plasticity, electrical conductivity and thermal conductivity, good corrosion resistance and excellent processing and welding performance, and is used for thin plate pressure vessels, pipelines, storage devices and heat exchangers.

[0003] The profile of aluminum alloy is often manufactured by split-flow extrusion process. The specific process is as follows: the heated blank is sent into the extrusion cylinder, enters the mold cavity under the action of the extrusion rod, and is split-welded, and is formed into a profile at the lower mold working belt and flows out from the outlet.

[0004] The content of Mn in aluminum alloy 3003 is high. Because the diffusion coefficient of Mn element is small, serious segregation is easy to occur. Homogenization heat treatment can improve the uniformity of the structure, make the segregation and enrichment of the partial compound dissolve and spheroidize, and improve the processability of split-flow extrusion. The time of homogenization heat treatment has a significant influence on the precipitation phase and recrystallization, so it is very important to develop a saving homogenization heat treatment process.

[0005] In the split-flow extrusion of aluminum alloy 3003 thin-walled parts, because the wall is thin, the extrusion ratio is large, and the flow resistance is large, the temperature and the extrusion speed are the key to the material forming control. High temperature will accelerate the growth of grains, and high temperature will reduce the extrusion force and the welding force. High speed will increase the temperature and the strain rate, increase the friction, and the stress and the welding force will fluctuate. Therefore, the size precision control of aluminum alloy 3003 thin-walled products is difficult, and there are few reports in the literature.

[0006] Through the search of the prior art, it is found that the Chinese patent document No. CN 108950322, published on December 7, 2018, discloses a thin-walled 6 series aluminum profile for rail transit car body and a preparation method thereof. The preparation method is mainly as follows: the homogenization temperature of the casting bar is 550-580℃, the holding time is 8-10h, and after discharging, it is cooled to room temperature by strong wind, and then heated and extruded. This process is mainly based on casting + extrusion + aging. By reducing the content of elements such as Mn and Cr, the recrystallization temperature in the alloy extrusion process is reduced, and the quenching temperature is strictly controlled to achieve the effect of supersaturated solid solution.

[0007] Another Chinese patent document No. CN 109666822, published on April 23, 2019, discloses a preparation method for producing 3003-H14 aluminum alloy battery shell material. The preparation method comprises the following steps: melting and casting, sawing, soaking, milling, heating, hot rolling, cold rolling, and annealing. The production preparation method ensures that the mechanical properties of the 3003-H14 aluminum alloy battery shell material are stable and qualified, the anisotropy is balanced during stamping, and the stamping performance is good. This process is mainly based on casting + rolling, and the ingot soaking temperature is 560℃, and the temperature is kept at 450℃ for 12h. The soaking process time is relatively long, and it is not economical and practical. It is very important to develop a saving type of uniform heat treatment process. SUMMARY

[0008] To solve the above problems, the purpose of the present application is to provide an aluminum alloy 3003 thin-walled part flow extrusion process. The present application aims to adjust the traditional 8-12h homogenization annealing to a shorter high-temperature annealing of 3-4h under the premise of strict control of alloy composition, and proposes a homogenization annealing and preheating integrated heating scheme. Aluminum alloy 3003 relies on the refining effect of trace rare earth elements in the alloy, and after two-stage homogenization annealing, severe flow extrusion thermal deformation and welding chamber high temperature and high pressure welding, can eliminate dendrites, reduce oxidation, control grain size, and also improve production efficiency.

[0009] The present application proposes a saving type of flow extrusion process for aluminum alloy 3003 (3003 alloy and 6 series aluminum alloy are different, and cannot be strengthened by heat treatment) thin-walled part forming, shortens the heating time, improves the production efficiency, reduces the production cost, and obtains good shape and size by controlling the extrusion temperature and speed.

[0010] The purpose of the present application can be realized by the following technical solutions:

[0011] The present application provides an aluminum alloy 3003 thin-walled part flow extrusion process, which specifically comprises the following steps:

[0012] The ingot is sequentially subjected to homogenization annealing and preheating integrated heating, mold heating, extrusion cylinder heating and flow extrusion treatment, and the aluminum alloy 3003 thin-walled part flow extrusion product is obtained after processing.

[0013] In an embodiment of the present application, the ingot comprises the following components by mass fraction:

[0014] Si: 0.05–0.1%, Fe: 0.3–0.4%, Cu: 0.05–0.1%, Mn: 1.05–1.1%, Mg: 0.008–0.01%, Zr: 0.004–0.005%, Cr: 0.004–0.005%, Ni: 0.004–0.005%, Zn: 0.008–0.01%, Ti: 0.02–0.025%, Ce: 0.04–0.05%, individual impurities ≤0.025%, total impurities ≤0.15%, the remainder is Al.

[0015] In one embodiment of the present invention, the ingot has dimensions of Φ85mm×300mm, and the wall thickness of the aluminum alloy 3003 thin-walled extrusion part is 1.2mm.

[0016] In one embodiment of the present invention, the homogenization annealing process is carried out at a temperature of 605-615°C for 3-4 hours.

[0017] In one embodiment of the present invention, the preheating process is carried out at a temperature of 500-520°C for 1.5-2 hours.

[0018] In one embodiment of the present invention, the temperature during the mold heating process is 510-520°C.

[0019] In one embodiment of the present invention, the temperature during the heating process of the extrusion cylinder is 380-400°C.

[0020] In one embodiment of the present invention, during the diversion extrusion process, the extrusion speed is 3.8 to 4.2 m / min.

[0021] In one embodiment of the present invention, the post-processing is air cooling followed by sawing.

[0022] In one embodiment of the present invention, the temperature is 150-200°C during the air cooling process.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The process of this invention can shorten the heating time of the split extrusion of thin-walled aluminum alloy 3003 parts and improve production efficiency; in the process of controlling the billet temperature, deformation temperature and deformation speed, higher dimensional accuracy and uniform grain size are obtained; the process of this invention also has very significant technical and economic benefits. Attached Figure Description

[0025] Figure 1 The image shows the EBSD diagram of the aluminum alloy 3003 thin-walled part produced by split extrusion in Example 1. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0027] Unless otherwise specified, all reagents used in the following embodiments are commercially available, and all detection methods, processes and conditions used are conventional detection methods, processes and conditions in the art.

[0028] Example 1

[0029] The split extrusion process for thin-walled aluminum alloy 3003 parts in this embodiment includes the following steps:

[0030] (1) Homogenization annealing and preheating of ingots are integrated: the homogenization annealing temperature of ingots is 605℃ and the annealing time is 4h; the preheating temperature is 500℃ and the preheating time is 2h. After the preheating is completed, the ingots are cooled to room temperature.

[0031] The chemical composition of the cast ingot after melting and casting is as follows (mass percentage): Si: 0.05%, Fe: 0.3%, Cu: 0.05%, Mn: 1.05%, Mg: 0.008%, Zr: 0.004%, Cr: ≤0.004%, Ni: ≤0.004%, Zn: 0.008%, Ti: 0.02%, Ce: 0.04%, with individual impurities ≤0.02%, total impurities ≤0.10%, and the remainder being Al; the dimensions of the ingot are Φ85mm × 300mm.

[0032] (2) Mold heating: Heat the mold to 510℃;

[0033] (3) Extrusion cylinder heating: heating the extrusion cylinder to 380℃;

[0034] (4) Dividing extrusion: The ingot is placed in a heated mold and then placed in a heated extrusion cylinder for dividing extrusion. The extrusion speed is controlled at 4.2 m / min to obtain the profile.

[0035] (5) Air cooling: The profile is rapidly cooled to below 150℃ using a fan before being sawn to obtain a thin-walled 3003 aluminum alloy part with a wall thickness of 1.2mm. Its EBSD diagram is shown below. Figure 1 As shown, through Figure 1 It can be observed that the aluminum alloy 3003 thin-walled parts prepared in this embodiment have high dimensional accuracy and uniform grain size.

[0036] Example 2

[0037] The split extrusion process for thin-walled aluminum alloy 3003 parts in this embodiment includes the following steps:

[0038] (1) Homogenization annealing and preheating of ingots are integrated: the homogenization annealing temperature of ingots is 615℃ and the annealing time is 3h; the preheating temperature is 520℃ and the preheating time is 1.5h. After the preheating is completed, the ingots are cooled to room temperature.

[0039] The chemical composition of the cast ingot after melting and casting is as follows (mass percentage): Si: 0.1%, Fe: 0.4%, Cu: 0.1%, Mn: 1.1%, Mg: 0.01%, Zr: 0.005%, Cr: 0.005%, Ni: 0.005%, Zn: 0.01%, Ti: 0.025%, Ce: 0.05%, with individual impurities ≤0.025% and total impurities ≤0.15%, the remainder being Al; the dimensions of the ingot are Φ85mm × 300mm.

[0040] (2) Mold heating: Heat the mold to 520℃;

[0041] (3) Extrusion cylinder heating: Heat the extrusion cylinder to 400℃;

[0042] (4) Divided extrusion: The ingot is placed in a heated mold and then placed in a heated extrusion cylinder for divided extrusion. The extrusion speed is controlled at 3.8 m / min to obtain the profile.

[0043] (5) Air cooling: The profile is quickly cooled to below 200°C by a fan and then sawn to obtain a thin-walled aluminum alloy 3003 part with a wall thickness of 1.2mm.

[0044] Example 3

[0045] The split extrusion process for thin-walled aluminum alloy 3003 parts in this embodiment includes the following steps:

[0046] (1) Homogenization annealing and preheating of ingots are integrated: the homogenization annealing temperature of the ingots is 610℃ and the annealing time is 3.5h; the preheating temperature is 510℃ and the preheating time is 1.8h. After the preheating is completed, the ingots are cooled to room temperature.

[0047] The chemical composition of the cast ingot after melting and casting is as follows (mass percentage): Si: 0.1%, Fe: 0.4%, Cu: 0.1%, Mn: 1.1%, Mg: 0.01%, Zr: 0.005%, Cr: 0.005%, Ni: 0.005%, Zn: 0.01%, Ti: 0.025%, Ce: 0.05%, with individual impurities ≤0.025% and total impurities ≤0.15%, the remainder being Al; the dimensions of the ingot are Φ85mm × 300mm.

[0048] (2) Mold heating: Heat the mold to 515℃;

[0049] (3) Extrusion cylinder heating: Heat the extrusion cylinder to 390℃;

[0050] (4) Dividing extrusion: The ingot is placed in a heated mold and then placed in a heated extrusion cylinder for dividing extrusion. The extrusion speed is controlled at 4.0 m / min to obtain the profile.

[0051] (5) Air cooling: The profile is quickly cooled to below 180°C by a fan and then sawn to obtain a thin-walled aluminum alloy 3003 part with a wall thickness of 1.2mm.

[0052] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the interpretation of the present invention, without departing from the scope of the invention, should be within the protection scope of the present invention.

Claims

1. A split-flow extrusion process for thin-walled aluminum alloy 3003 parts, characterized in that, Specifically, the following steps are included: The ingot is subjected to homogenization annealing and preheating integrated heating, mold heating, extrusion cylinder heating and diversion extrusion treatment in sequence. The post-treatment results in a diversion extrusion part of aluminum alloy 3003 with a wall thickness of 1.2mm. The ingot comprises the following components by mass fraction: Si: 0.05~0.1%, Fe: 0.3~0.4%, Cu: 0.05~0.1%, Mn: 1.05~1.1%, Mg: 0.008~0.01%, Zr: 0.004~0.005%, Cr: 0.004~0.005%, Ni: 0.004~0.005%, Zn: 0.008~0.01%, Ti: 0.02~0.025%, Ce: 0.04~0.05%, individual impurities ≤0.025%, total impurities ≤0.15%, the remainder is Al; During the homogenization annealing process, the temperature is 605~615℃ and the time is 3~4h; During the preheating process, the temperature is 500~520℃ and the time is 1.5~2 hours; During the mold heating process, the temperature is 510~520℃; During the heating process of the extrusion cylinder, the temperature is 380~400℃; During the split extrusion process, the extrusion speed is 3.8~4.2m / min; The post-processing involves air cooling followed by sawing. During the air-cooling process, the temperature is 150~200℃.

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