Aluminum alloy for preparing traction beam of external bogie of train and preparation method of aluminum alloy

Abstract

The invention discloses an aluminum alloy for preparing a traction beam of an external bogie of a train and a preparation method of the aluminum alloy, and belongs to the technical field of alloys for high-speed trains. The aluminum alloy contains Zn, Mg, Cu, Zr, Ti, Mn, Ni, La and other elements, and lanthanum can refine grains, improve the metallographic structure and form a dispersion strengthening phase, so that the strength and toughness of the alloy are improved; the nickel and the aluminum element can form a solid solution, so that the alloy structure is more compact, and the obtained aluminum alloy shows higher resistance when bearing external force and is not prone to deformation or fracture. According to the method, the aluminum alloy is manufactured through two-step superplastic die forging, after two-step die forging, plastic deformation of the alloy is uniform, the grain size is small and uniform, mechanical properties of the aluminum alloy are improved, the aluminum alloy particularly has good fatigue performance, and the aluminum alloy has good safety and reliability while light weight of the aluminum alloy is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of alloys for high-speed trains, and in particular relates to an aluminum alloy for preparing a traction beam of an external bogie of a train and a preparation method thereof. Background Art

[0002] With the gradual increase in the operating speed of high-speed trains and the important demand for energy conservation and environmental protection, the further lightweighting of high-speed trains has become a basic element in the design and manufacture of high-speed trains, and is also an inevitable trend.

[0003] In recent years, with the increasing requirements for high speed and lightweight in railway transportation, the performance requirements for key component support seats are also increasing. The high-speed requirements of trains have been seriously affected by the high density of steel traction beam products. Achieving weight reduction while meeting the high-standard mechanical performance requirements of the support seat is a major reform and structural adjustment faced by the development of high-speed trains. The implementation of speed-up and safety development technologies requires in-depth structural optimization and component lightweighting of support seat products. The external bogie traction beams of currently operating high-speed trains are mainly made of ductile iron materials, resulting in a relatively high overall quality of the bogie traction beams, which is not conducive to increasing the speed of the train. Summary of the invention

[0004] In view of the above-mentioned prior art, the present invention provides an aluminum alloy for preparing a train external bogie traction beam and a preparation method thereof, so as to solve the technical problems of the existing external bogie traction beam material having heavy weight and poor mechanical properties.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is to provide an aluminum alloy for preparing a traction beam of an external bogie of a train, comprising the following components in mass percentage:

[0006] Zn 10-12%, Mg 3-5%, Cu 2-4%, Zr 0.5-1%, Ti 0.05-0.2%, Mn 0.05-0.2%, Ni 0.1-0.5%, La 0.05-0.45%, and the balance is Al and inevitable impurities.

[0007] Based on the above technical solution, the present invention can also be improved as follows.

[0008] Furthermore, the aluminum alloy used to prepare the traction beam of the train external bogie includes the following components in percentage by mass:

[0009] Zn 11%, Mg 4%, Cu 3%, Zr 0.8%, Ti 0.1%, Mn 0.1%, Ni 0.3%, La 0.2%, and the balance is Al and inevitable impurities.

[0010] The present invention also discloses a method for preparing the aluminum alloy for preparing a traction beam of an external bogie of a train, comprising the following steps:

[0011] S1: preparing raw materials according to the mass percentage of each element in the aluminum alloy, smelting and pouring the raw materials to obtain Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot;

[0012] S2: homogenizing the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot;

[0013] S3: performing hot plastic deformation processing on the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot after homogenization treatment;

[0014] S4: performing superplastic die forging on the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot that has been subjected to hot plastic deformation processing;

[0015] S5: heat treating the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot after superplastic die forging to obtain.

[0016] Further, the raw materials include aluminum ingots, Al-Cu master alloys, Al-5Zr master alloys, Al-5Ti master alloys, Al-10Mn master alloys, Al-La10 master alloys, Al-Ni10 master alloys, zinc ingots and magnesium ingots.

[0017] Further, the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot is prepared by the following steps:

[0018] The aluminum ingot of the formula amount is melted, and the melt is heated to 680-700°C, and then Al-Cu master alloy is added, and the melt is kept warm for 30-60 minutes; then the melt temperature is raised to 720-740°C, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-La10 master alloy and Al-Ni10 master alloy are added, and the melt is kept warm for 20-30 minutes; then the melt temperature is lowered to 690-710°C, zinc ingot and magnesium ingot are added, and the melt is kept warm for 30-60 minutes; then the melt is heated to 720-730°C, stirred for 2-5 minutes, and then allowed to stand until the melt temperature reaches 710-720°C, and then cast to obtain Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot.

[0019] Furthermore, the homogenization treatment method in S2 is: remove the outer skin of the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot, then heat it to 380-450°C, keep it warm for 8-14 hours; then heat it to 450-490°C, keep it warm for 20-26 hours, and then water-cool it at room temperature.

[0020] Furthermore, the hot plastic deformation processing method in S3 is: heating the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot after homogenization treatment to 380-450°C, keeping it warm for 2-6 hours, and then hot extruding with an extrusion ratio of 10-30:1.

[0021] Furthermore, the superplastic die forging process in S4 is divided into superplastic die forging pre-forging and superplastic die forging final forging.

[0022] Furthermore, the superplastic die forging process includes the following steps: heating the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot that has been subjected to the hot plastic deformation process to 380-450°C, keeping the temperature for 2-6 hours, and then heating the ingot at 380-450°C at a temperature of 1×10 -5 ~1×10 -2 mm / s die forging rate to obtain a pre-forged billet; then at 380-450℃ at 1×10 -5 ~1×10 -2 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet.

[0023] Furthermore, the heat treatment in S5 is as follows: heating the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot after superplastic forging to 450-500°C, keeping it at that temperature for 2-6 hours, and water cooling it at room temperature; then heating it to 110-140°C, keeping it at that temperature for 18-26 hours, and air cooling it to room temperature.

[0024] The beneficial effects of the present invention are:

[0025] 1. The aluminum alloy of the present invention contains elements such as Zn, Mg, Cu, Zr, Ti, Mn, Ni, and La. Among them, Cu, Zr, Ti, Mn, Ni, and La are introduced through master alloys, which can not only effectively improve the utilization rate of the elements, but also reduce the occurrence of impurities and segregation, thereby ensuring the performance of the obtained aluminum alloy.

[0026] 2. Adding Zn to the aluminum alloy of the present invention can form a strengthening phase Mg / Zn2 in the alloy, thereby significantly strengthening the alloy; and the presence of zinc enables the alloy to form a protective film on the surface of the alloy when it is corroded to prevent further corrosion. Adding magnesium to the alloy can form a solid solution, thereby improving the tensile strength and yield limit of the aluminum alloy. Copper has excellent solid solution strengthening and aging strengthening effects. Introducing copper into aluminum alloys can form intermetallic compounds such as CuAl2 with aluminum, which can significantly improve the strength and hardness of the aluminum alloy. Adding zirconium to aluminum alloys can refine the grain structure of the aluminum alloy and may form zirconium-containing compounds, thereby improving the strength and toughness of the aluminum alloy, while improving its thermal stability; at the same time, zirconium can also inhibit the recrystallization of the alloy during deformation and heat treatment, and promote the precipitation of uniformly dispersed second phase particles in the matrix, thereby improving the comprehensive performance of the alloy. The present invention introduces titanium into the aluminum alloy, and can form compounds such as TiAl3 phase in the aluminum alloy. The TiAl3 phase has high hardness and strength, and can significantly improve the tensile strength of the aluminum alloy. The TiAl3 phase also has good oxidation resistance, and can improve the corrosion resistance of the aluminum alloy. In addition, the introduction of titanium can also reduce the density of the aluminum alloy, thereby achieving the purpose of lightweight. Manganese is added to the aluminum alloy to form a solid solution in the alloy, and intermetallic compounds such as MnAl6 are precipitated, which can effectively improve the strength of the aluminum alloy and make it have excellent tensile strength. Lanthanum is also added to the aluminum alloy of the present invention, and lanthanum can refine the grains, improve the metallographic structure, and form a dispersion strengthening phase inside the alloy, thereby effectively improving the strength and toughness of the alloy. Nickel is also added to the aluminum alloy of the present invention. Nickel can form a solid solution with aluminum element to make the alloy structure more compact, so that the obtained aluminum alloy exhibits higher resistance when subjected to external force and is not easy to deform or break; and the addition of nickel can also improve the forgeability of the aluminum alloy, making it easier to process and form. During the processing, the nickel-containing aluminum alloy exhibits better plasticity and ductility, and can more easily achieve the desired shape and size; in addition, the addition of nickel can also improve the deformation resistance of the aluminum alloy, making it less likely to deform during use and maintaining a stable shape and size.

[0027] 3. The present invention adopts two-step superplastic die forging to manufacture aluminum alloy. The design of two-step superplastic die forging avoids the formation of defects of aluminum alloy during the die forging process, reduces stress concentration, and effectively guarantees the mechanical properties of aluminum alloy; and after two-step die forging, the plastic deformation of the alloy is uniform, and the grain size is small and uniform, which is conducive to improving and enhancing the mechanical properties of aluminum alloy, especially having better fatigue performance, ensuring the lightweight of aluminum alloy while having better safety and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the structure of the train's external bogie traction beam. DETAILED DESCRIPTION

[0029] The specific implementation modes of the present invention are described in detail below with reference to the embodiments.

[0030] Example 1

[0031] An aluminum alloy for preparing a traction beam of an external bogie of a train, comprising the following components in percentage by mass:

[0032] Zn 11%, Mg 4%, Cu 3%, Zr 0.8%, Ti 0.1%, Mn 0.1%, Ni 0.3%, La 0.2%, and the balance is Al and inevitable impurities.

[0033] The aluminum alloy used to prepare the train external bogie traction beam in this embodiment is prepared by the following steps:

[0034] S1: preparing raw materials according to the mass percentage of each element in the alloy, the raw materials including aluminum ingot, Al-Cu master alloy, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-La10 master alloy, Al-Ni10 master alloy, zinc ingot and magnesium ingot; smelting and casting the raw materials according to the following steps to prepare Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La casting billet;

[0035] The aluminum ingot of the formula amount is melted, and the melt is heated to 690°C, and then Al-Cu master alloy is added, and the melt is kept warm for 45 minutes; then the melt temperature is raised to 730°C, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-La10 master alloy and Al-Ni10 master alloy are added, and the melt is kept warm for 25 minutes; then the melt temperature is lowered to 700°C, zinc ingot and magnesium ingot are added, and the melt is kept warm for 45 minutes; then the melt is heated to 725°C, stirred for 4 minutes, and then allowed to stand until the melt temperature reaches 715°C, and then cast to obtain Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot;

[0036] S2: removing the outer skin of the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot, then heating to 400°C at a heating rate of 5°C / min, and keeping it warm for 12 hours; then heating to 470°C at a heating rate of 5°C / min, keeping it warm for 24 hours, and then water cooling at room temperature to complete the homogenization treatment of the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot;

[0037] S3: heating the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot after homogenization to 400°C at a heating rate of 5°C / min, keeping the temperature for 4 hours, and then hot extruding with an extrusion ratio of 25:1 to complete the hot plastic deformation processing;

[0038] S4: The Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot that had been subjected to thermoplastic deformation was heated to 400°C at a heating rate of 5°C / min, kept at this temperature for 4 h, and then heated at 400°C at a temperature of 1×10 -3 mm / s die forging rate to obtain a pre-forged billet; then at 400℃ at 1×10 -3 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet, completing the superplastic die forging process;

[0039] S5: The Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot after superplastic forging treatment is heated to 480°C at a heating rate of 5°C / min, kept at this temperature for 4 hours, and water-cooled at room temperature; then, the temperature is heated to 120°C at a heating rate of 5°C / min, kept at this temperature for 20 hours, and then air-cooled to room temperature.

[0040] Example 2

[0041] An aluminum alloy for preparing a traction beam of an external bogie of a train, comprising the following components in percentage by mass:

[0042] Zn 10%, Mg 5%, Cu 2%, Zr 1%, Ti 0.05%, Mn 0.2%, Ni 0.1%, La 0.45%, and the balance is Al and inevitable impurities.

[0043] The aluminum alloy used to prepare the train external bogie traction beam in this embodiment is prepared by the following steps:

[0044] S1: preparing raw materials according to the mass percentage of each element in the alloy, the raw materials including aluminum ingot, Al-Cu master alloy, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-La10 master alloy, Al-Ni10 master alloy, zinc ingot and magnesium ingot; smelting and casting the raw materials according to the following steps to prepare Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La casting billet;

[0045] The aluminum ingot of the formula amount is melted, and the melt is heated to 680°C, and then Al-Cu master alloy is added, and the melt is kept warm for 60 minutes; then the melt temperature is raised to 720°C, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-La10 master alloy and Al-Ni10 master alloy are added, and the melt is kept warm for 30 minutes; then the melt temperature is lowered to 690°C, zinc ingot and magnesium ingot are added, and the melt is kept warm for 60 minutes; then the melt is heated to 720°C, stirred for 5 minutes, and then allowed to stand until the melt temperature reaches 710°C, and then cast to obtain Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot;

[0046] S2: removing the outer skin of the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot, then heating to 380°C at a heating rate of 5°C / min, and keeping it warm for 14 hours; then heating to 450°C at a heating rate of 5°C / min, keeping it warm for 26 hours, and then water cooling at room temperature to complete the homogenization treatment of the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot;

[0047] S3: heating the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot after homogenization to 380°C at a heating rate of 5°C / min, keeping the temperature for 6 hours, and then hot extruding with an extrusion ratio of 10:1 to complete the hot plastic deformation processing;

[0048] S4: The Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot that had been subjected to thermoplastic deformation was heated to 380°C at a heating rate of 5°C / min, kept at this temperature for 6 h, and then heated to 1×10 -5 mm / s die forging rate to obtain a pre-forged billet; then at 380 ° C at 1 × 10 -5 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet, completing the superplastic die forging process;

[0049] S5: The Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot after superplastic forging treatment is heated to 450°C at a heating rate of 5°C / min, kept warm for 6 hours, and water-cooled at room temperature; then, the temperature is heated to 110°C at a heating rate of 5°C / min, kept warm for 26 hours, and then air-cooled to room temperature.

[0050] Example 3

[0051] An aluminum alloy for preparing a traction beam of an external bogie of a train, comprising the following components in percentage by mass:

[0052] Zn 12%, Mg 3%, Cu 4%, Zr 0.5%, Ti 0.2%, Mn 0.05%, Ni 0.5%, La 0.05%, and the balance is Al and inevitable impurities.

[0053] The aluminum alloy used to prepare the train external bogie traction beam in this embodiment is prepared by the following steps:

[0054] S1: preparing raw materials according to the mass percentage of each element in the alloy, the raw materials including aluminum ingot, Al-Cu master alloy, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-La10 master alloy, Al-Ni10 master alloy, zinc ingot and magnesium ingot; smelting and casting the raw materials according to the following steps to prepare Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La casting billet;

[0055] Melt the aluminum ingot of the formula amount, and heat the melt to 700°C, then add Al-Cu master alloy, and keep warm for 30 minutes; then heat the melt to 740°C, add Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-La10 master alloy and Al-Ni10 master alloy, and keep warm for 20 minutes; then reduce the melt temperature to 710°C, add zinc ingot and magnesium ingot, and keep warm for 30 minutes; then heat the melt to 730°C, stir for 2 minutes, and then stand until the melt temperature reaches 720°C, and cast to obtain Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot;

[0056] S2: removing the outer skin of the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot, then heating to 450°C at a heating rate of 5°C / min, and keeping it warm for 8 hours; then heating to 490°C at a heating rate of 5°C / min, keeping it warm for 20 hours, and then water cooling at room temperature to complete the homogenization treatment of the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot;

[0057] S3: heating the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot after homogenization to 450°C at a heating rate of 5°C / min, keeping the temperature for 2 hours, and then hot extruding with an extrusion ratio of 30:1 to complete the hot plastic deformation processing;

[0058] S4: The Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot that had been subjected to thermoplastic deformation was heated to 450°C at a heating rate of 5°C / min, kept at this temperature for 2 h, and then heated to 380°C at a temperature of 1×10 -2mm / s die forging rate to obtain a pre-forged billet; then, the pre-forged billet was heated at 450°C at 1×10 -2 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet, completing the superplastic die forging process;

[0059] S5: The Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot after superplastic forging treatment is heated to 500°C at a heating rate of 5°C / min, kept at this temperature for 2 hours, and water-cooled at room temperature; then, the temperature is heated to 140°C at a heating rate of 5°C / min, kept at this temperature for 18 hours, and then air-cooled to room temperature to obtain.

[0060] Comparative Example 1

[0061] An aluminum alloy for preparing a traction beam of an external bogie of a train, comprising the following components in percentage by mass:

[0062] Zn 11%, Mg 4%, Cu 3%, Zr 0.8%, Ti 0.1%, Mn 0.1%, La 0.2%, and the balance is Al and inevitable impurities.

[0063] The aluminum alloy used to prepare the train external bogie traction beam in this comparative example is prepared by the following steps:

[0064] S1: preparing raw materials according to the mass percentage of each element in the alloy, the raw materials including aluminum ingot, Al-Cu master alloy, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-La10 master alloy, zinc ingot and magnesium ingot; smelting and casting the raw materials according to the following steps to prepare Al-Zn-Mg-Cu-Zr-Ti-Mn-La ingot;

[0065] The aluminum ingot of the formula amount is melted, and the melt is heated to 690°C, and then Al-Cu master alloy is added, and the melt is kept warm for 45 minutes; then the melt temperature is raised to 730°C, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy and Al-La10 master alloy are added, and the melt is kept warm for 25 minutes; then the melt temperature is lowered to 700°C, zinc ingot and magnesium ingot are added, and the melt is kept warm for 45 minutes; then the melt is heated to 725°C, stirred for 4 minutes, and then allowed to stand until the melt temperature reaches 715°C, and then cast to obtain Al-Zn-Mg-Cu-Zr-Ti-Mn-La ingot;

[0066] S2: removing the outer skin of the Al-Zn-Mg-Cu-Zr-Ti-Mn-La ingot, then heating to 400°C at a heating rate of 5°C / min, and keeping it warm for 12 hours; then heating to 470°C at a heating rate of 5°C / min, keeping it warm for 24 hours, and then water cooling at room temperature to complete the homogenization treatment of the Al-Zn-Mg-Cu-Zr-Ti-Mn-La ingot;

[0067] S3: heating the Al-Zn-Mg-Cu-Zr-Ti-Mn-La ingot after homogenization to 400°C at a heating rate of 5°C / min, keeping the temperature for 4 hours, and then hot extruding with an extrusion ratio of 25:1 to complete the hot plastic deformation processing;

[0068] S4: The Al-Zn-Mg-Cu-Zr-Ti-Mn-La ingot that had been subjected to thermoplastic deformation was heated to 400°C at a heating rate of 5°C / min, kept at that temperature for 4 h, and then heated at 400°C at a temperature of 1×10 -3 mm / s die forging rate to obtain a pre-forged billet; then at 400℃ at 1×10 -3 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet, completing the superplastic die forging process;

[0069] S5: The Al-Zn-Mg-Cu-Zr-Ti-Mn-La ingot after superplastic forging treatment is heated to 480°C at a heating rate of 5°C / min, kept at this temperature for 4 hours, and water-cooled at room temperature; then, the temperature is heated to 120°C at a heating rate of 5°C / min, kept at this temperature for 20 hours, and then air-cooled to room temperature.

[0070] Comparative Example 2

[0071] An aluminum alloy for preparing a traction beam of an external bogie of a train, comprising the following components in percentage by mass:

[0072] Zn 11%, Mg 4%, Cu 3%, Zr 0.8%, Ti 0.1%, Mn 0.1%, Ni 0.3%, and the balance is Al and inevitable impurities.

[0073] The aluminum alloy used to prepare the train external bogie traction beam in this comparative example is prepared by the following steps:

[0074] S1: preparing raw materials according to the mass percentage of each element in the alloy, the raw materials including aluminum ingot, Al-Cu master alloy, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-Ni10 master alloy, zinc ingot and magnesium ingot; smelting and casting the raw materials according to the following steps to prepare Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni casting billet;

[0075] The aluminum ingot of the formula amount is melted, and the melt is heated to 690°C, and then Al-Cu master alloy is added, and the melt is kept warm for 45 minutes; then the melt temperature is raised to 730°C, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy and Al-Ni10 master alloy are added, and the melt is kept warm for 25 minutes; then the melt temperature is lowered to 700°C, zinc ingot and magnesium ingot are added, and the melt is kept warm for 45 minutes; then the melt is heated to 725°C, stirred for 4 minutes, and then allowed to stand until the melt temperature reaches 715°C, and then cast to obtain Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni ingot;

[0076] S2: removing the outer skin of the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni ingot, then heating to 400°C at a heating rate of 5°C / min, and keeping it warm for 12 hours; then heating to 470°C at a heating rate of 5°C / min, keeping it warm for 24 hours, and then water cooling at room temperature to complete the homogenization treatment of the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni ingot;

[0077] S3: heating the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni ingot after homogenization to 400°C at a heating rate of 5°C / min, keeping the temperature for 4 hours, and then hot extruding with an extrusion ratio of 25:1 to complete the hot plastic deformation processing;

[0078] S4: The Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni ingot that had been subjected to thermoplastic deformation was heated to 400°C at a heating rate of 5°C / min, kept at that temperature for 4 h, and then heated at 400°C at a temperature of 1×10 -3 mm / s die forging rate to obtain a pre-forged billet; then at 400℃ at 1×10 -3 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet, completing the superplastic die forging process;

[0079] S5: The Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni ingot after superplastic forging treatment is heated to 480°C at a heating rate of 5°C / min, kept at this temperature for 4 hours, and water-cooled at room temperature; then, the temperature is heated to 120°C at a heating rate of 5°C / min, kept at this temperature for 20 hours, and then air-cooled to room temperature.

[0080] Comparative Example 3

[0081] An aluminum alloy for preparing a traction beam of an external bogie of a train, comprising the following components in percentage by mass:

[0082] Zn 11%, Mg 4%, Cu 3%, Zr 0.8%, Ti 0.1%, Mn 0.1%, and the balance being Al and inevitable impurities.

[0083] The aluminum alloy used to prepare the train external bogie traction beam in this comparative example is prepared by the following steps:

[0084] S1: preparing raw materials according to the mass percentage of each element in the alloy, the raw materials including aluminum ingot, Al-Cu master alloy, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, zinc ingot and magnesium ingot; smelting and casting the raw materials according to the following steps to prepare Al-Zn-Mg-Cu-Zr-Ti-Mn casting billet;

[0085] The aluminum ingot of the formula amount is melted, and the melt is heated to 690°C, and then Al-Cu master alloy is added, and the melt is kept warm for 45 minutes; then the melt temperature is raised to 730°C, Al-5Zr master alloy, Al-5Ti master alloy and Al-10Mn master alloy are added, and the melt is kept warm for 25 minutes; then the melt temperature is lowered to 700°C, zinc ingot and magnesium ingot are added, and the melt is kept warm for 45 minutes; then the melt is heated to 725°C, stirred for 4 minutes, and then allowed to stand until the melt temperature reaches 715°C, and then cast to obtain Al-Zn-Mg-Cu-Zr-Ti-Mn ingot;

[0086] S2: removing the outer skin of the Al-Zn-Mg-Cu-Zr-Ti-Mn ingot, then heating to 400°C at a heating rate of 5°C / min, and keeping it warm for 12 hours; then heating to 470°C at a heating rate of 5°C / min, keeping it warm for 24 hours, and then water cooling at room temperature to complete the homogenization treatment of the Al-Zn-Mg-Cu-Zr-Ti-Mn ingot;

[0087] S3: heating the Al-Zn-Mg-Cu-Zr-Ti-Mn ingot after homogenization to 400°C at a heating rate of 5°C / min, keeping the temperature for 4 hours, and then hot extruding with an extrusion ratio of 25:1 to complete the hot plastic deformation processing;

[0088] S4: The Al-Zn-Mg-Cu-Zr-Ti-Mn ingot that had been subjected to thermoplastic deformation was heated to 400°C at a heating rate of 5°C / min, kept at that temperature for 4 h, and then heated at 400°C at a temperature of 1×10 -3 mm / s die forging rate to obtain a pre-forged billet; then at 400℃ at 1×10 -3 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet, completing the superplastic die forging process;

[0089] S5: The Al-Zn-Mg-Cu-Zr-Ti-Mn ingot after superplastic forging treatment is heated to 480°C at a heating rate of 5°C / min, kept at this temperature for 4 hours, and water-cooled at room temperature; then, the temperature is heated to 120°C at a heating rate of 5°C / min, kept at this temperature for 20 hours, and then air-cooled to room temperature.

[0090] Results Analysis

[0091] The aluminum alloy of the train external bogie traction beam prepared in the above-mentioned embodiments and comparative examples is respectively made into an external bogie traction beam, and the structure of the external bogie traction beam is as follows: Figure 1 Then, the performance test of the prepared external bogie traction beam was carried out. The test items included tensile strength, yield strength, fatigue resistance, etc. Among them, the fatigue test parameters were: stress ratio of 0.1, vibration frequency of 60-70HZ, and number of cycles of 1×10 7 The test results are shown in Table 1.

[0092] Table 1 Comprehensive performance of built-in bogie frame support

[0093]

[0094] Although the specific implementation of the present invention is described in detail in conjunction with the embodiments, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. An aluminum alloy for preparing a traction beam of an external bogie of a train, characterized in that: The following components are included in mass percentage: Zn 10-12%, Mg 3-5%, Cu 2-4%, Zr 0.5-1%, Ti 0.05-0.2%, Mn 0.05-0.2%, Ni 0.1-0.5%, La 0.05-0.45%, and the balance is Al and inevitable impurities.

2. The aluminum alloy for preparing a traction beam of an external bogie of a train according to claim 1, characterized in that: The following components are included in mass percentage: Zn 11%, Mg 4%, Cu 3%, Zr 0.8%, Ti 0.1%, Mn 0.1%, Ni 0.3%, La 0.2%, and the balance is Al and inevitable impurities.

3. The method for preparing an aluminum alloy for preparing a traction beam of an external bogie of a train according to claim 1 or 2, characterized in that: The following steps are involved: S1: preparing raw materials according to the mass percentage of each element in the aluminum alloy, smelting and pouring the raw materials to obtain Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot; S2: homogenizing the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot; S3: performing hot plastic deformation processing on the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot after homogenization treatment; S4: performing superplastic die forging on the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot that has been subjected to hot plastic deformation processing; S5: heat treating the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot after superplastic die forging to obtain.

4. The preparation method according to claim 3, characterized in that: The raw materials include aluminum ingots, Al-Cu master alloys, Al-5Zr master alloys, Al-5Ti master alloys, Al-10Mn master alloys, Al-La10 master alloys, Al-Ni10 master alloys, zinc ingots and magnesium ingots.

5. The preparation method according to claim 4, characterized in that: The Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot is prepared by the following steps: The aluminum ingot of the formula amount is melted, and the melt is heated to 680-700°C, and then Al-Cu master alloy is added, and the melt is kept warm for 30-60 minutes; then the melt temperature is raised to 720-740°C, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-La10 master alloy and Al-Ni10 master alloy are added, and the melt is kept warm for 20-30 minutes; then the melt temperature is lowered to 690-710°C, zinc ingot and magnesium ingot are added, and the melt is kept warm for 30-60 minutes; then the melt is heated to 720-730°C, stirred for 2-5 minutes, and then allowed to stand until the melt temperature reaches 710-720°C, and then cast to obtain Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot.

6. The preparation method according to claim 3, characterized in that: The homogenization treatment method in S2 is: remove the outer skin of the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot, then heat it to 380-450°C, keep it warm for 8-14 hours; then heat it to 450-490°C, keep it warm for 20-26 hours, and then water-cool it at room temperature.

7. The preparation method according to claim 3, characterized in that: The hot plastic deformation processing method in S3 is: heating the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot after homogenization treatment to 380-450°C, keeping it warm for 2-6 hours, and then hot extruding it with an extrusion ratio of 10-30:

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8. The preparation method according to claim 3, characterized in that: The superplastic die forging process in S4 is divided into superplastic die forging pre-forging and superplastic die forging final forging.

9. The preparation method according to claim 8, characterized in that: The superplastic die forging process includes the following steps: heating the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La billet that has been subjected to thermoplastic deformation to 380-450°C, keeping the temperature for 2-6 hours, and then heating the billet at 380-450°C at a temperature of 1×10 -5 ~1×10 -2 mm / s die forging rate to obtain a pre-forged billet; then at 380-450℃ at 1×10 -5 ~1×10 -2 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet.

10. The preparation method according to claim 3, characterized in that: The heat treatment in S5 is as follows: heating the Al-Zn-Mg-Cu-Zr-Ti-Mn-Ni-La ingot after superplastic forging to 450-500°C, keeping it at that temperature for 2-6 hours, and water cooling it at room temperature; then heating it to 110-140°C, keeping it at that temperature for 18-26 hours, and air cooling it to room temperature.

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