阅读说明：本技术 一种轨道列车车体薄壁铝型材 (Rail train automobile body thin-wall aluminum profile ) 是由 唐开健 王超 李�亨 贡玉楼 于 2019-11-19 设计创作，主要内容包括：本发明公开了一种轨道列车车体薄壁铝型材,包括下述重量百分比的成分：Si 0.66-0.72％,Fe 0.18-0.24％,Mn 0.24-0.3％,Mg 0.42-0.46％,Cr 0.04-0.08％,Ti 0.04-0.08％,Cu 0.03-0.05％,La 0.14-0.2％,Sr 0.12-0.16％,Ce 0.05-0.08％,余量为Al。本发明的轨道列车车体薄壁铝型材具有优良的抗拉强度、疲劳强度、延伸率和抗腐蚀性,综合性能良好,能更好地满足轨道列车车体的使用要求,提高其运行寿命和安全性。(The invention discloses a thin-wall aluminum profile of a rail train body, which comprises the following components in percentage by weight: 0.66-0.72% of Si, 0.18-0.24% of Fe, 0.24-0.3% of Mn, 0.42-0.46% of Mg, 0.04-0.08% of Cr, 0.04-0.08% of Ti, 0.03-0.05% of Cu, 0.14-0.2% of La, 0.12-0.16% of Sr, 0.05-0.08% of Ce and the balance of Al. The thin-wall aluminum profile for the rail train body has the advantages of excellent tensile strength, fatigue strength, elongation and corrosion resistance, good comprehensive performance, capability of better meeting the use requirement of the rail train body and prolonging the service life and safety of the rail train body.)

1. The thin-wall aluminum profile for the train body of the rail train is characterized by comprising the following components in percentage by weight:

0.66-0.72% of Si, 0.18-0.24% of Fe, 0.24-0.3% of Mn, 0.42-0.46% of Mg, 0.04-0.08% of Cr, 0.04-0.08% of Ti, 0.03-0.05% of Cu, 0.14-0.2% of La, 0.12-0.16% of Sr, 0.05-0.08% of Ce and the balance of Al.

2. The thin-wall aluminum profile for the railway train body as claimed in claim 1, wherein the Sr + La + Ce in the components of the aluminum profile is more than or equal to 0.35%.

3. The thin-wall aluminum profile for the railway train body as claimed in claim 1 or 2, which is prepared by the following steps:

s1, homogenizing annealing: firstly, carrying out staged homogenization annealing treatment on an aluminum alloy ingot obtained by casting according to the components at 535-585 ℃, and then carrying out air cooling to normal temperature;

s2, hot extrusion: carrying out hot extrusion on the cast ingot cooled in the step S1 on an extruder at the extrusion temperature of 500 ℃ and 515 ℃, and then carrying out water-cooling quenching to the normal temperature;

s3, solution treatment: carrying out solution treatment on the section blank obtained in the step S2 at 540-570 ℃ for 1-1.5h, and then carrying out water-cooling quenching to normal temperature;

s4, artificial aging: and (5) artificially aging the section blank obtained after cooling in the step S3 at the temperature of 165-180 ℃ for 7-9h, and cooling to normal temperature by air cooling to obtain the section blank.

4. The thin-walled aluminum profile of railway train body according to claim 3, wherein in step S1, the specific steps of the step homogenization annealing include: firstly, the temperature is preserved for 2-4h at 535-550 ℃, then the temperature is raised to 560-575 ℃ for 3-5h, and finally the temperature is preserved for 5-8min at 580-585 ℃.

5. The thin-wall aluminum profile for rail train bodies as claimed in claim 3 or 4, wherein in step S2, the specific conditions of hot extrusion are as follows: the extrusion ratio is 41.5-45.5, and the extrusion speed is 1-2.5 m/min.

6. The thin-wall aluminum profile for the railway train body according to any one of claims 3 to 5, wherein in the step S2, the water-cooling quenching comprises the following specific steps: cooling to 280-310 ℃ at a cooling rate of 8-10 ℃/s, cooling to 150-180 ℃ at a cooling rate of 4-5 ℃/s, and cooling to normal temperature at a cooling rate of 2-2.5 ℃/s.

7. The thin-walled aluminum profile for rail train bodies as claimed in any one of claims 3 to 6, wherein in step S3, the cooling rate of the water-cooling quenching is 20-30 ℃/S.

8. The thin-walled aluminum profile for rail train bodies as claimed in any one of claims 3 to 7, wherein in step S4, the cooling rate of the air cooling is 3 to 5 ℃/S.

Technical Field

The invention relates to the technical field of aluminum alloy materials, in particular to a thin-wall aluminum profile of a rail train body.

Background

The aluminum alloy has the advantages of small specific gravity, high specific strength, good processability and the like, and is widely applied in various fields. With the development of rail train body processing technology and the trend of light weight of vehicles, aluminum profiles are gradually applied to structural materials of rail train bodies. The rail train body is generally a thin-wall hollow section, has the characteristics of large size, large section, complex shape and the like, and has complex and changeable external environment contacted with the rail train body, and has a certain probability of corrosion or stress fracture, so that higher requirements on the tensile strength, fatigue strength, elongation, corrosion resistance and other properties of the body material are provided. At present, most of materials applied to hollow sections of rail train bodies are 6005A aluminum alloys, the welding performance is good, and the mechanical properties are general. In order to meet the use requirements of the rail train body and improve the service life and safety of the rail train body, the overall performance of the aluminum profile needs to be comprehensively improved.

Disclosure of Invention

Based on the technical problems in the background art, the invention provides a thin-wall aluminum profile for a rail train body, which has excellent tensile strength, fatigue strength, elongation and corrosion resistance and good overall performance.

The invention provides a thin-wall aluminum profile of a rail train body, which comprises the following components in percentage by weight:

0.66-0.72% of Si, 0.18-0.24% of Fe, 0.24-0.3% of Mn, 0.42-0.46% of Mg, 0.04-0.08% of Cr, 0.04-0.08% of Ti, 0.03-0.05% of Cu, 0.14-0.2% of La, 0.12-0.16% of Sr, 0.05-0.08% of Ce and the balance of Al.

Preferably, in the components of the aluminum profile, Sr + La + Ce is more than or equal to 0.35 percent.

Preferably, the preparation method of the thin-wall aluminum profile of the railway train body comprises the following steps:

s1, homogenizing annealing: firstly, carrying out staged homogenization annealing treatment on an aluminum alloy ingot obtained by casting according to the components at 535-585 ℃, and then carrying out air cooling to normal temperature;

s2, hot extrusion: carrying out hot extrusion on the cast ingot cooled in the step S1 on an extruder at the extrusion temperature of 500 ℃ and 515 ℃, and then carrying out water-cooling quenching to the normal temperature;

s3, solution treatment: carrying out solution treatment on the section blank obtained in the step S2 at 540-570 ℃ for 1-1.5h, and then carrying out water-cooling quenching to normal temperature;

s4, artificial aging: and (5) artificially aging the section blank obtained after cooling in the step S3 at the temperature of 165-180 ℃ for 7-9h, and cooling to normal temperature by air cooling to obtain the section blank.

Preferably, in step S1, the step of step-wise homogenizing annealing includes: firstly, the temperature is preserved for 2-4h at 535-550 ℃, then the temperature is raised to 560-575 ℃ for 3-5h, and finally the temperature is preserved for 5-8min at 580-585 ℃.

Preferably, in step S2, the specific conditions of the hot extrusion are: the extrusion ratio is 41.5-45.5, and the extrusion speed is 1-2.5 m/min.

Preferably, in step S2, the water-cooling quenching specifically includes: cooling to 280-310 ℃ at a cooling rate of 8-10 ℃/s, cooling to 150-180 ℃ at a cooling rate of 4-5 ℃/s, and cooling to normal temperature at a cooling rate of 2-2.5 ℃/s.

Preferably, in the step S3, the cooling rate of the water-cooling quenching is 20-30 ℃/S.

Preferably, in the step S4, the cooling rate of the air cooling is 3-5 ℃/S.

The invention has the following beneficial effects:

in the raw material components of the present invention, Mg and Si form a main strengthening phase Mg₂Si; cr can regulate strengthening phase Mg₂Si is precipitated at grain boundary, Mn can refine recrystallized grains and promote Mg₂Uniform distribution of Si phase; cu can generate solid solution strengthening effect, so that the strength of the section is improved, but the corrosion resistance is reduced; la can form Al in the matrix₁₁La₃When the rare earth compound is in the corrosion-resistant phase, the corrosion resistance of the section is improved, the adverse effect of Cu on the corrosion resistance is compensated, and Al in the alloy can be affected₈SiFe₂Isocompound phase and main strengthening phase Mg₂The Si phase plays a thinning role to further improve the strength, plasticity and corrosion resistance of the section, but along with the increase of the La content, the La-containing crystalline phase is greatly aggregated to form a coarse blocky phase which is unfavorable for the performance of the alloy, so the single La effect is limited; through the coordination of La, Sr and Ce with proper content, not only can the formation of a coarse rare earth compound phase be avoided, the adverse effect on the alloy performance can be avoided, but also Mg can be better promoted₂Refining Si phase to form coarse dendritic Mg₂The Si phase is changed into fine, dispersed and uniformly distributed particles, and the strength, plasticity and corrosion resistance of the alloy are improved. In the preparation method, a proper staged homogenization annealing process is selected, so that the method can not only ensure that the annealing furnace is used for annealing the steelThe diffusion of atoms in a solid phase is more sufficient, the homogenization degree of matrix components is improved, the intragranular segregation and brittle phases are reduced, the number of dispersed phase particles is increased, and the size of the dispersed phase particles is reduced, so that the toughness and the corrosion resistance of the section bar are improved, and the overburning caused by overhigh annealing temperature can be avoided; by selecting proper extrusion conditions and a quenching process after extrusion, particularly controlling different cooling speeds after extrusion, and carrying out water cooling quenching by stages, the method is favorable for improving the solid solution degree of alloy elements and promoting the refinement of dispersed phases, thereby improving the strength and plasticity of the section bar and avoiding the uneven alloy structure and the twisting deformation of the section bar caused by the overhigh cooling speed; by selecting a proper cooling mode and cooling speed after solution treatment and artificial aging, coarsening of a strengthening phase can be further relieved, and residual stress in the section can be reduced, so that the mechanical property and the service durability of the section are improved. Based on the raw material components and the preparation process, the thin-wall aluminum profile for the rail train body has excellent tensile strength, fatigue strength, elongation and corrosion resistance, and good comprehensive performance, can better meet the use requirements of the rail train body, and improves the service life and safety of the rail train body.

Detailed Description

The technical solution of the present invention will be described in detail below with reference to specific examples.