A 6061Z aluminum alloy profile and its processing technology

Abstract

This scheme discloses a 6061Z aluminum alloy profile in the field of aluminum alloy production technology, the chemical composition of which includes, by mass percentage, Si: 0.4-0.8, Mg: 0.4-0.8, Fe≤0.5, Cu≤0.05, Mn≤0.08, Cr≤0.08, Ti≤0.05, Zn≤0.05, and the balance is Al. The processing includes the following steps: S1, batching: batching according to the chemical composition of the above-mentioned 6061Z aluminum alloy profile; S2, aluminum alloy ingot preparation: adding the prepared aluminum alloy raw material into a smelting furnace to melt into a molten liquid, and then casting the molten liquid into an aluminum alloy ingot; S3, homogenization treatment; S4, first cooling treatment; S5, extrusion molding; S6, quenching cooling; S7, artificial aging. This application obtains a 6061Z aluminum alloy profile with high strength and good corrosion resistance by optimizing the chemical composition and processing technology of the aluminum alloy profile.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum alloy production, and particularly relates to a 6061Z aluminum alloy profile and a processing technology thereof. Background Art

[0002] 6061 aluminum alloy is a high-quality aluminum alloy product produced by heat treatment pre-stretching process. It has good formability, weldability, and machinability. It also has medium strength and can maintain good operability after annealing.

[0003] In the prior art, the mass percentage of the alloy components of 6061 aluminum alloy is generally: Si: 0.4-0.8, Mg: 0.8-1.2, Fe≤0.7, Cu: 0.15-0.40, Mn: 0.15, Cr: 0.04-0.35, Ti: 0.15, Zn: 0.25, and the balance is Al. In order to further improve the overall performance or partial performance of 6061 aluminum alloy, it is necessary to adjust the composition of the aluminum alloy or improve the processing technology, so as to obtain aluminum alloy profiles with the required performance. For example, the patent with the publication number of "CN113355569A" discloses "a 6-series aluminum alloy profile suitable for aluminum template and its preparation method". This patent: by adjusting the alloy composition and heat treatment process of the aluminum alloy ingot, not only the average main cylinder pressure of the extrusion process of the 6-series aluminum alloy profile suitable for aluminum template is effectively reduced, but also the aluminum template profile finally obtained has better tensile strength and yield strength. In addition, the patent performs surface brushing or peeling treatment on the surface of the homogenized aluminum alloy ingot to avoid as much as possible the inclusion of impurities in the surface segregation layer during the extrusion process, which may affect the strength and corrosion resistance of the profile. However, the peeling operation increases the production cost, and since there is a problem of recrystallization due to processing strain as the driving force during the extrusion molding stage, recrystallization, especially coarse recrystallization, will lead to reduced corrosion resistance. Therefore, the corrosion resistance of the 6 series aluminum alloy profile prepared by this method is only equal to or slightly worse than that of the conventional 6061 aluminum alloy. Summary of the invention

[0004] The present invention aims to provide a 6061Z aluminum alloy profile with higher strength and good corrosion resistance.

[0005] A 6061Z aluminum alloy profile in the present solution has the following chemical compositions in terms of mass percentage: Si: 0.4-0.8, Mg: 0.4-0.8, Fe≤0.5, Cu≤0.05, Mn≤0.08, Cr≤0.08, Ti≤0.05, Zn≤0.05, and the balance is Al.

[0006] Furthermore, the chemical composition of the 6061Z aluminum alloy profile includes, by mass percentage, Si: 0.5-0.7, Mg: 0.5-0.7, 0.1≤Fe≤0.5, 0.01≤Cu≤0.05, 0.02≤Mn≤0.08, 0.01≤Cr≤0.08, 0.01≤Ti≤0.05, 0.01≤Zn≤0.05, and the balance is Al.

[0007] Furthermore, the chemical composition of the 6061Z aluminum alloy profile includes, by mass percentage, Si: 0.7, Mg: 0.6, Fe: 0.3, Cu: 0.02, Mn: 0.04, Cr: 0.02, Ti: 0.02, Zn: 0.01, and the balance is Al.

[0008] A processing technology for 6061Z aluminum alloy profiles includes the following steps:

[0009] S1. Ingredients: Ingredients are prepared according to the chemical composition of the above 6061Z aluminum alloy profile;

[0010] S2. Preparation of aluminum alloy ingots: Add the prepared aluminum alloy raw materials into a smelting furnace to melt into molten liquid, and then cast the molten liquid into

[0011] It is an aluminum alloy ingot;

[0012] S3, homogenization treatment: placing the aluminum alloy ingot in a homogenization furnace for homogenization treatment, the homogenization treatment temperature is 540-560°C, and the homogenization treatment time is 6-12h;

[0013] S4, first cooling treatment: cooling the aluminum alloy ingot after homogenization treatment to 150-180° C. at a cooling rate of 100-120° C. / hour, and then cooling to room temperature at a temperature of 20-30° C.;

[0014] S5, extrusion molding: heating the aluminum alloy ingot after the primary cooling treatment to 580-600° C. at an extrusion speed of 3-5 m / min to obtain an extruded material;

[0015] S6, quenching and cooling: quenching and cooling the extruded material to room temperature at a cooling rate of 150-160°C / s;

[0016] S7. Artificial aging: Artificial aging is performed on the extruded profiles after quenching and cooling. The aging temperature is 220℃~230℃ and the aging insulation is 2~3h.

[0017] Furthermore, during the homogenization treatment, the homogenization temperature is 550° C. and the homogenization time is 8 h.

[0018] Furthermore, during the first cooling treatment, the cooling rate was 110° C. / h.

[0019] Furthermore, during extrusion molding, the aluminum alloy ingot that has undergone the primary cooling treatment is heated to 590° C. at an extrusion speed of 5 m / min to obtain an extruded material.

[0020] Furthermore, during quench cooling, the cooling rate was 155° C. / s.

[0021] Beneficial effects of the present application: The present application optimizes the chemical composition of the aluminum alloy profile, performs a first cooling after homogenizing the aluminum alloy ingot, and then cools the extruded material at a high temperature by rapid cooling, thereby obtaining a 6061Z aluminum alloy profile with high strength and good corrosion resistance without performing surface brushing or peeling treatment on the surface of the aluminum alloy ingot. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a longitudinal cross-sectional metallographic structure diagram of a 6061Z aluminum alloy profile prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0023] The following is further described in detail through specific implementation methods:

[0024] Embodiment 1: A processing technology for a 6061Z aluminum alloy profile comprises the following steps:

[0025] S1. Ingredients: The ingredients are prepared according to the chemical composition of the above-mentioned 6061Z aluminum alloy profile. The chemical composition of the 6061Z aluminum alloy profile includes, by mass percentage, Si: 0.7, Mg: 0.6, Fe: 0.3, Cu: 0.02, Mn: 0.04, Cr: 0.02, Ti: 0.02, Zn: 0.01, and the balance is Al and unavoidable impurities.

[0026] S2. Preparation of aluminum alloy ingots: Add the prepared aluminum alloy raw materials into a smelting furnace to melt into molten liquid, and then cast the molten liquid into

[0027] It is an aluminum alloy ingot, which can be cast according to the existing conventional casting method;

[0028] S3, homogenization treatment: placing the aluminum alloy ingot in a homogenization furnace for homogenization treatment, the homogenization treatment temperature is 550°C, and the homogenization treatment time is 8 hours;

[0029] S4, first cooling treatment: immediately cool the aluminum alloy ingot after homogenization treatment to 160°C at a cooling rate of 110°C / hour, and then cool to room temperature at a temperature of 20°C. Cooling to room temperature means cooling to the cooling temperature, such as the room temperature here is the cooling temperature of 20°C;

[0030] S5, extrusion molding: heating the aluminum alloy ingot after the primary cooling treatment to 590° C. at an extrusion speed of 5 m / min to obtain an extruded material;

[0031] S6, quenching and cooling: immediately quench the extruded material to room temperature, where the room temperature is 20-30°C, and the cooling rate is 155°C / s;

[0032] S7. Artificial aging: Artificial aging is performed on the extruded profiles after quenching and cooling. The aging temperature is 230°C and the aging insulation is 2.5 hours.

[0033] Embodiment 2: A processing technology for a 6061Z aluminum alloy profile comprises the following steps:

[0034] S1. Ingredients: The ingredients are prepared according to the chemical composition of the above-mentioned 6061Z aluminum alloy profile. The chemical composition of the 6061Z aluminum alloy profile includes, by mass percentage, Si: 0.8, Mg: 0.7, Fe: 0.5, Cu: 0.04, Mn: 0.07, Cr: 0.05, Ti: 0.05, Zn: 0.03, and the balance is Al and unavoidable impurities.

[0035] S2. Preparation of aluminum alloy ingots: Add the prepared aluminum alloy raw materials into a smelting furnace to melt into molten liquid, and then cast the molten liquid into

[0036] It is an aluminum alloy ingot, which can be cast according to the existing conventional casting method;

[0037] S3, homogenization treatment: placing the aluminum alloy ingot in a homogenization furnace for homogenization treatment, the homogenization treatment temperature is 560°C, and the homogenization treatment time is 6 hours;

[0038] S4, first cooling treatment: immediately cool the aluminum alloy ingot after homogenization treatment to 180°C at a cooling rate of 100°C / hour, and then cool to room temperature at a temperature of 30°C. Cooling to room temperature means cooling to the cooling temperature, such as the room temperature here is the cooling temperature of 30°C;

[0039] S5, extrusion molding: heating the aluminum alloy ingot after the primary cooling treatment to 580° C. at an extrusion speed of 3 m / min to obtain an extruded material;

[0040] S6, quenching and cooling: immediately quench the extruded material to room temperature, where the room temperature is 20-30°C, and the cooling rate is 160°C / s;

[0041] S7. Artificial aging: Artificial aging is performed on the extruded profiles after quenching and cooling. The aging temperature is 220°C and the aging insulation is 3h.

[0042] Comparative Example 1: A processing technology for a 6061Z aluminum alloy profile, which differs from Example 1 only in that:

[0043] The first cooling treatment in step S4 is: immediately using a fan to cool the aluminum alloy ingot after homogenization to room temperature.

[0044] Comparative Example 2: A 6 series aluminum alloy profile was prepared according to the method of Example 1 in the patent publication number “CN113355569A” and the patent name “A 6 series aluminum alloy profile suitable for aluminum formwork and its preparation method”.

[0045] The longitudinal section metallographic structure diagram of the 6061Z aluminum alloy profile prepared in Example 1 is shown in the attached figure. Figure 1 shown.

[0046] Six pieces of aluminum alloy profiles prepared in Examples 1 to 2 and Comparative Example 1 were taken for corrosion resistance test, and the 18 tested 6061Z aluminum alloy profiles were cut into test pieces with a length of 100 mm, a width of 100 mm and a thickness of 7 mm.

[0047] Test conditions:

[0048] The test piece was first cleaned and degreased, then dehydrated with ethanol, and then left to dry for 24 hours before weighing its mass with an accuracy of 0.1 mg.

[0049] Test equipment: circulating salt spray corrosion test chamber, spray medium: 5% NaCl solution by mass, pH value is about 6.5~7.2.

[0050] The sample was placed in a cyclic salt spray corrosion test box for accelerated corrosion test, the test process was: salt spray (5% NaCl solution, 35°C, 2h) -> drying (60°C, 4h) -> wet heat (60°C, 98%RH, 2h); a total of 8 hours was one cycle, and 120 corrosion test cycles (3 pieces of aluminum alloy profiles prepared in Examples 1 to 2 and Comparative Example 1) and 360 corrosion test cycles (3 pieces of aluminum alloy profiles prepared in Examples 1 to 2 and Comparative Example 1) were carried out respectively. After the corrosion test, take out the test piece, remove the corrosion products and calculate the mass loss caused by corrosion. Specifically, place the test piece in 70% (mass fraction) nitric acid solution for 10 minutes, then take it out, rinse it repeatedly in white water for 3 to 4 times, then rinse it with distilled water for 2 times, then dehydrate it with ethanol, and finally dry it with hot air (50°C). After cooling, weigh it with an accuracy of 0.1 mg, and then calculate the weight loss of corrosion test by weight loss method. The specific results are shown in the following table:

[0051]

[0052] Ten pieces of aluminum alloy profiles prepared in Examples 1 to 2 and Comparative Example 1 were taken for mechanical property testing (testing tensile strength and yield strength), and the test results are shown in the following table:

[0053]

[0054] It can be seen from the experimental results that the 6061Z aluminum alloy profiles prepared in Examples 1 to 2 of the application document have good mechanical properties and corrosion resistance.

[0055] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A 6061Z aluminum alloy profile, characterized in that: The chemical composition is as follows by mass percentage: Si: 0.4-0.8, Mg: 0.4-0.8, Fe≤0.5, Cu≤0.05, Mn≤0.08, Cr≤0.08, Ti≤0.05, Zn≤0.05, and the balance is Al; the preparation comprises the following steps: S1. Ingredients: Ingredients are prepared according to the chemical composition of the above 6061Z aluminum alloy profile; S2. Preparation of aluminum alloy ingots: adding the prepared aluminum alloy raw materials into a smelting furnace to melt into a molten liquid, and then casting the molten liquid into aluminum alloy ingots; S3. Homogenization treatment: placing the aluminum alloy ingot in a homogenization furnace for homogenization treatment at a temperature of 540 to 560° C. for a homogenization time of 6 to 12 hours; S4, first cooling treatment: cooling the aluminum alloy ingot after homogenization treatment to 150-180° C. at a cooling rate of 100-120° C. / hour, and then cooling to room temperature at a temperature of 20-30° C.; S5, extrusion molding: heating the aluminum alloy ingot after the primary cooling treatment to 580-600° C. at an extrusion speed of 3-5 m / min to obtain an extruded material; S6, quenching and cooling: quenching and cooling the extruded material to room temperature at a cooling rate of 150-160°C / s; S7. Artificial aging: Artificial aging is performed on the extruded profiles after quenching and cooling. The aging temperature is 220℃~230℃ and the aging insulation is 2~3h.

2. The 6061Z aluminum alloy profile according to claim 1, characterized in that: The chemical composition in mass percentage is: Si: 0.5~0.7, Mg: 0.5~0.7, 0.1≤Fe≤0.5, 0.01≤Cu≤0.05, 0.02≤Mn≤0.08, 0.01≤Cr≤0.08, 0.01≤Ti≤0.05, 0.01≤Zn≤0.05, and the balance is Al.

3. The 6061Z aluminum alloy profile according to claim 2, characterized in that: The chemical composition in terms of mass percentage includes: Si: 0.7, Mg: 0.6, Fe: 0.3, Cu: 0.02, Mn: 0.04, Cr: 0.02, Ti: 0.02, Zn: 0.01, and the balance is Al.

4. A 6061Z aluminum alloy profile according to any one of claims 1 to 3, characterized in that: During the homogenization treatment, the homogenization temperature is 550° C. and the homogenization time is 8 h.

5. The 6061Z aluminum alloy profile according to claim 4, characterized in that: During the first cooling treatment, the cooling rate was 110°C / h.

6. The 6061Z aluminum alloy profile according to claim 5, characterized in that: During extrusion molding, the aluminum alloy ingot that has undergone the primary cooling treatment is heated to 590° C. at an extrusion speed of 5 m / min to obtain an extruded material.

7. The 6061Z aluminum alloy profile according to claim 6, characterized in that: During quenching cooling, the cooling rate is 155℃ / s.

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