High-strength aluminum alloy profile for a crash beam and method for producing the same

Abstract

The application discloses a high-strength aluminum alloy profile for a crash beam and a preparation method thereof. The aluminum alloy profile comprises, in percentage by mass, Si: 0.42%-0.62%; Fe: 0.15%-0.30%; Cu: 0.18%-0.35%; Mn: <=0.15%; Mg: 0.87%-1.07%; Cr: 0.06%-0.24%; Zn: <=0.10%; Ti: 0.02%-0.14%; La-based rare earth: 0.05%-0.15%; Ge: 0.02%-0.05%; and the balance of Al and inevitable impurities. The application optimizes the components of the 6-series aluminum alloy, reduces the content of Fe and Zn, introduces a small amount of Ge, Ge can replace part of Si, compared with Si, forms a composite phase with higher density and better coherence with the matrix, and improves the strength of the aluminum alloy. In addition, Sc is also introduced, and Sc and Ge have a good synergistic effect with other elements, which significantly improves the strength and toughness of the aluminum alloy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bumper materials, in particular to a high-strength aluminum alloy profile for a crash beam and a preparation method thereof. BACKGROUND

[0002] The vehicle crash beam is a key component of the vehicle crash system. With the increasing requirements of the vehicle industry for the safety performance of the crash system and the increasing requirements for the light weight of the vehicle, aluminum alloy extruded profiles have become the preferred material for vehicle crash beams.

[0003] At present, the strength of conventional 6-series aluminum materials is low, and although 7-series high-strength aluminum materials have excellent light weight effect, the material toughness is poor. Some technologies have also developed aluminum alloys with high strength and excellent toughness. For example, CN118086732A discloses an aluminum profile and a preparation method and application thereof. The components of the aluminum profile include Mg: 0.8-1.2%; Si: 0.7-1%; Cu: 0.3-0.7%; Mn: 0.4-0.8%; Cr+V: 0.1-0.3%; rare earth elements 0.01-0.1%; Fe: ≤0.3%; the balance is Al and unavoidable impurities. The high toughness of the aluminum profile is ensured by adding V and rare earth elements, and the high strength is ensured by controlling Mg, Si, Cu and other elements. However, the size and area of the Mg2Si particles that do not melt into the aluminum profile need to be strictly controlled, which increases the difficulty of production process and related characterization. CN110055442A discloses an aluminum alloy profile for producing a high-strength ultra-light full-aluminum vehicle frame and a preparation method thereof. The aluminum alloy profile includes the following components by weight percentage: Si: 0.65-0.75%, Fe: 0.17-0.22%, Cu: 0.17-0.22%, Mn: 0.08-0.12%, Mg: 0.85-0.95%, Cr: 0.06-0.11%, B: 0.03-0.06%, Mo: 0.015-0.025%, Zn: 0.03-0.05%, Ti: 0.03-0.05%, and the balance is aluminum and unavoidable impurities. The surface quality and welding quality of the aluminum alloy product are improved by the synergistic effect of B, Mo and Mn, Cr, Ti in the formula; the surface quality and impact resistance of the aluminum alloy product are improved by the synergistic effect of Mo and Mg, Mo and Al. However, coarse borides may be segregated at the grain boundaries, becoming stress concentration points and reducing toughness.

[0004] Therefore, it is necessary to provide an aluminum alloy profile with high strength and excellent toughness, and a simple preparation process. SUMMARY

[0005] In order to solve the problems in the prior art, the application provides a high-strength aluminum alloy profile for a crash beam, which comprises, in percentage by mass, Si: 0.42% to 0.62%; Fe: 0.15% to 0.30%; Cu: 0.18% to 0.35%; Mn: <=0.15%; Mg: 0.87% to 1.07%; Cr: 0.06% to 0.24%; Zn: <=0.10%; Ti: 0.02% to 0.14%; La-based rare earth: 0.05% to 0.15%; Ge: 0.02% to 0.05%; and the balance of Al and inevitable impurities.

[0006] The aluminum alloy profile of the application is based on a 6-series aluminum alloy 6061, the main elements of which are Mg and Si, followed by Cu, and then Mn, Cr and Ti. The Mg2Si strengthening phase formed by Mg and Si is crucial to the strength. Cu can increase the heat treatment strengthening effect, inhibit the extrusion effect, and form a Cu2Mg8Si6Al5 phase, further improving the strength. The trace elements Mn, Cr and Ti can improve the strength and corrosion resistance, and at the same time inhibit recrystallization and refine the grains; Ti can refine the grains to a certain extent and also form an alloy with Al, playing a role in refining the casting and weld structures. Fe tends to form coarse AlFeSi phases with Si and Mn, reducing the plasticity and corrosion resistance, and is generally considered to have an inhibitory effect on the performance of aluminum alloys, so the content needs to be strictly controlled, and the total content of Mn and Fe needs to be considered. Zn has little effect on the strength, but excessive amounts will deteriorate the overall performance, so the content also needs to be controlled. Increasing the contents of Mg and Si can improve the tensile strength, but will reduce the elongation. The ratio of Mg and Si (Mg / Si ratio) is crucial to the formation of the strengthening phase, and sufficient Mg2Si phase can only be formed when the ratio reaches about 1.73. If Si is too much, excess Si phase or AlMnSi phase may be formed, which has less strengthening effect than Mg2Si, thereby affecting the performance. On the basis of optimizing the contents of Zn, Fe and other elements, the application adds a small amount of Ge, which can replace part of Si, form a composite phase with higher density and better coherence with the matrix than Si, and improve the strength of the aluminum alloy.

[0007] Sc and Al can form a nanoscale Al3Sc precipitate phase, refining the strength of the alloy and improving the toughness. Studies have shown that the tensile strength of an aluminum alloy containing 0.1% Sc can reach 400 MPa, and the elongation remains above 18%. However, Sc is expensive, and its role is unpredictable based on different aluminum alloy formulations. On the basis of the basic aluminum alloy formulation of the application, optimizing the mass ratio of Sc and Ge can not only reduce the amount of Sc, but also significantly improve the performance of the aluminum alloy.

[0008] Further, the high-strength aluminum alloy profile for the bumper beam comprises 0.01%~0.03% Sc in addition to Al and inevitable impurities.

[0009] Further, the mass ratio of Sc and Ge is 1:2~3.

[0010] It should be noted that the La-based rare earth includes La, Ce, Pr, Nd, Pm, Sm, Eu, etc., which mainly plays the role of refining grains, purifying melt and neutralizing impurities in the aluminum alloy. The type does not need to be strictly limited and one or more of them can be freely selected. For example, one of La and Ce can be selected.

[0011] The application also provides a preparation method of the high-strength aluminum alloy profile for the bumper beam, comprising,

[0012] After the aluminum ingot is melted, Mn and Cr are added, then other raw materials except rare earth are added, and finally aluminum rare earth alloy is added for smelting to obtain an aluminum alloy melt;

[0013] The aluminum alloy melt is filtered to obtain an alloy liquid to be used;

[0014] The alloy liquid to be used is cast into a blank;

[0015] The blank is sequentially subjected to homogenization, extrusion molding, heat treatment, aging treatment and stretch straightening to obtain the high-strength aluminum alloy profile for the bumper beam.

[0016] Further, the smelting temperature is 650~800℃;

[0017] The homogenization is performed at 530~580℃ for 6~8h;

[0018] The heat treatment temperature is 500~560℃.

[0019] Further, the filtering is performed by using a two-stage ceramic filter plate, and the mesh numbers of the two-stage ceramic filter plate are 30~40 mesh and 50~60 mesh respectively.

[0020] Further, during the extrusion molding, the homogenized blank is heated to 500~560℃ at a temperature gradient of 6~8℃ / min, and then extrusion molding is performed by using a 460~500℃ extrusion die at an extrusion speed of 4~6m / min.

[0021] Further, the aging treatment is performed at 185±5℃ for 120~240min.

[0022] Further, the stretching amount of the stretch straightening is 1%~5%.

[0023] Further, the alloy liquid is allowed to stand at 660-770 DEG C for 0.5-2 hours before being cast into a blank.

[0024] Compared with the prior art, the application has the following beneficial effects:

[0025] The application optimizes the components of the 6-series aluminum alloy, reduces the content of Fe and Zn, and introduces a small amount of Ge, which can replace part of Si, form a composite phase with higher density and better coherence with the matrix than Si, and improve the strength of the aluminum alloy. In addition, Sc is also introduced, which has a good synergistic effect with Ge and other elements, and significantly improves the strength and toughness of the aluminum alloy. DETAILED DESCRIPTION

[0026] The endpoints of the ranges and any values described in this application are not limited to the precise values stated. The ranges and values should be construed to be approximations that allow for significant variation. Various embodiments can vary from the described embodiments, as they are intended to be illustrative, and not restrictive, of the application. The scope of the application is not to be determined by the specific examples provided in the specification, but only by the plain meaning of the language.

[0027] The technical solutions in the embodiments of the application will be clearly and completely described in combination with specific embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work are within the protection scope of the application. EMBODIMENT

[0028] A high-strength aluminum alloy profile for a crash beam, which comprises, in mass percentage, Si: 0.57%; Fe: 0.16%; Cu: 0.30%; Mn: 0.10%; Mg: 0.98%; Cr: 0.16%; Zn: 0.08%; Ti: 0.12%; Ce: 0.08%; Ge: 0.03%; and the balance of Al and inevitable impurities. The preparation method comprises the following steps:

[0029] (1) Melting: aluminum ingots are added to a melting furnace, the temperature of the melting furnace is set to 750 DEG C, when the temperature of the aluminum ingots rises to the set value and starts to melt, powdery Mn and Cr are added to the melting furnace, then aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, pure copper, magnesium ingots, aluminum-zinc intermediate alloy, aluminum-titanium intermediate alloy and aluminum-germanium intermediate alloy are added, finally cerium-aluminum intermediate alloy is added and stirred, and the material is completely melted at 750 DEG C after uniform stirring, to obtain an aluminum alloy melt;

[0030] (2) Filtering: filtering the aluminum alloy melt by using double-stage ceramic filter plates with mesh numbers of 30 mesh and 60 mesh respectively to obtain the alloy liquid to be used;

[0031] (3) Casting: casting the alloy liquid to be used into an aluminum rod, and then standing at 700℃ for 1h to obtain a billet;

[0032] (4) Homogenization treatment: placing the billet in a homogenization treatment device, and standing at 550℃ for 7h to obtain an aluminum alloy ingot after homogenization treatment;

[0033] (5) Extrusion molding: heating the aluminum alloy ingot to 530℃ at a temperature gradient of 7℃ / min, and then extruding and molding in an extruder, wherein the temperature of the extrusion cylinder is 430℃, the temperature of the extrusion die is 480℃, and the extrusion speed is 5m / min;

[0034] (6) Heat treatment: performing online solid solution quenching treatment on the product after extrusion molding in step (5) at 530℃, and standing for 1.5h;

[0035] (7) Aging treatment: standing the product after heat treatment in step (6) at 185℃ for 180min;

[0036] (8) Tension straightening: performing tension straightening on the product after heat treatment in step (7) with a tension amount of 3% to obtain a high-strength aluminum alloy profile for a crash beam. Embodiment

[0037] A high-strength aluminum alloy profile for a crash beam, the aluminum alloy profile has components in mass percentage of Si: 0.57%; Fe: 0.16%; Cu: 0.30%; Mn: 0.10%; Mg: 0.98%; Cr: 0.16%; Zn: 0.08%; Ti: 0.12%; Ce: 0.08%; Ge: 0.03%; Sc: 0.010%; and the balance of Al and inevitable impurities. The preparation method thereof comprises the following steps:

[0038] (1) Melting: adding aluminum ingots into a melting furnace, setting the temperature of the melting furnace to 750℃, adding powdery Mn and Cr into the melting furnace when the temperature of the aluminum ingots rises to the set value and starts to melt, then adding aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, pure copper, magnesium ingots, aluminum-zinc intermediate alloy, aluminum-titanium intermediate alloy, aluminum-germanium intermediate alloy and aluminum-scandium intermediate alloy, and finally adding cerium-aluminum intermediate alloy and stirring, stirring uniformly at 750℃ until the materials are completely melted to obtain an aluminum alloy melt;

[0039] (2) Filtering: filtering the aluminum alloy melt by using double-stage ceramic filter plates with mesh numbers of 30 mesh and 60 mesh respectively to obtain the alloy liquid to be used;

[0040] (3) Casting: the alloy liquid is cast into aluminum bar, and then is placed at 700°C for 1 h to obtain a blank;

[0041] (4) Homogenization treatment: the blank is placed in a homogenization treatment device and is kept at 550°C for 7 h to obtain an aluminum alloy ingot after homogenization treatment;

[0042] (5) Extrusion molding: the aluminum alloy ingot is heated to 530°C at a temperature gradient of 7°C / min, and then is extruded in an extruder, wherein the temperature of the extrusion cylinder is 430°C, the temperature of the extrusion die is 480°C, and the extrusion speed is 5 m / min;

[0043] (6) Heat treatment: the product after the extrusion molding in step (5) is subjected to online solid solution quenching treatment at 530°C for 1.5 h;

[0044] (7) Aging treatment: the product after the heat treatment in step (6) is kept at 185°C for 180 min;

[0045] (8) Tension straightening: the product after the heat treatment in step (7) is subjected to tension straightening, and the tension amount is 3% to obtain a high-strength aluminum alloy profile for a crash beam. Embodiment

[0046] A high-strength aluminum alloy profile for a crash beam, which comprises, in mass percent, Si: 0.57%; Fe: 0.16%; Cu: 0.30%; Mn: 0.10%; Mg: 0.98%; Cr: 0.16%; Zn: 0.08%; Ti: 0.12%; Ce: 0.08%; Ge: 0.03%; Sc: 0.012%; and the balance of Al and inevitable impurities. The preparation method comprises the following steps:

[0047] (1) Melting: aluminum ingots are added to a melting furnace, the temperature of the melting furnace is set to 750°C, when the temperature of the aluminum ingots rises to the set value and starts to melt, powdery Mn and Cr are added to the melting furnace, then aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, pure copper, magnesium ingots, aluminum-zinc intermediate alloy, aluminum-titanium intermediate alloy, aluminum-germanium intermediate alloy and aluminum-scandium intermediate alloy are added, and finally cerium-aluminum intermediate alloy is added and stirred, and the stirring is performed uniformly at 750°C until the materials are completely melted to obtain an aluminum alloy melt;

[0048] (2) Filtration: the aluminum alloy melt is filtered by using double-stage ceramic filter plates with mesh numbers of 30 mesh and 60 mesh respectively to obtain an alloy liquid;

[0049] (3) Casting: the alloy liquid is cast into aluminum bar, and then is placed at 700°C for 1 h to obtain a blank;

[0050] (4) homogenization treatment: the blank is placed in a homogenization treatment device, and is kept at 550°C for 7h to obtain an aluminum alloy ingot after homogenization treatment;

[0051] (5) extrusion molding: the aluminum alloy ingot is heated to 530°C at a temperature gradient of 7°C / min, and then is subjected to extrusion molding in an extruder, wherein the temperature of the extrusion cylinder is 430°C, the temperature of the extrusion die is 480°C, and the extrusion speed is 5m / min;

[0052] (6) heat treatment: the product after the extrusion molding in step (5) is subjected to online solution quenching treatment at 530°C for 1.5h;

[0053] (7) aging treatment: the product after the heat treatment in step (6) is kept at 185°C for 180min;

[0054] (8) stretch straightening: the product after the heat treatment in step (7) is subjected to stretch straightening, and the stretching amount is 3%, to obtain a high-strength aluminum alloy profile for a crash beam. Embodiment

[0055] A high-strength aluminum alloy profile for a crash beam, which comprises, in mass percent, Si: 0.57%; Fe: 0.16%; Cu: 0.30%; Mn: 0.10%; Mg: 0.98%; Cr: 0.16%; Zn: 0.08%; Ti: 0.12%; Ce: 0.08%; Ge: 0.03%; Sc: 0.015%; and the balance of Al and unavoidable impurities. The preparation method comprises the following steps:

[0056] (1) melting: aluminum ingots are added to a melting furnace, the temperature of the melting furnace is set to 750°C, when the temperature of the aluminum ingots rises to the set value and starts to melt, powdery Mn and Cr are added to the melting furnace, then aluminum-silicon intermediate alloy, aluminum-iron intermediate alloy, pure copper, magnesium ingots, aluminum-zinc intermediate alloy, aluminum-titanium intermediate alloy, aluminum-germanium intermediate alloy, and aluminum-scandium intermediate alloy are added, and finally cerium-aluminum intermediate alloy is added and stirred, and the material is completely melted at 750°C after stirring to obtain an aluminum alloy melt;

[0057] (2) filtration: the aluminum alloy melt is filtered by using double-stage ceramic filter plates with mesh sizes of 30 mesh and 60 mesh respectively to obtain an alloy liquid to be used;

[0058] (3) casting: the alloy liquid to be used is cast into an aluminum bar, and then is kept at 700°C for 1h to obtain a blank;

[0059] (4) homogenization treatment: the blank is placed in a homogenization treatment device, and is kept at 550°C for 7h to obtain an aluminum alloy ingot after homogenization treatment;

[0060] (5) Extrusion: The aluminum alloy ingot is heated to 530°C at a temperature gradient of 7°C / min, and then extruded in an extruder, wherein the temperature of the extrusion cylinder is 430°C, the temperature of the extrusion die is 480°C, and the extrusion speed is 5 m / min;

[0061] (6) Heat treatment: The product extruded in step (5) is subjected to online solution quenching treatment at 530°C for 1.5 h;

[0062] (7) Aging treatment: The product subjected to the heat treatment in step (6) is aged at 185°C for 180 min;

[0063] (8) Stretch straightening: The product subjected to the heat treatment in step (7) is subjected to stretch straightening at a stretch amount of 3%, to obtain a high-strength aluminum alloy profile for a crash beam.

[0064] Comparative Example 1

[0065] The difference from Example 1 is that the aluminum alloy profile does not contain Ge.

[0066] Comparative Example 2

[0067] The difference from Example 1 is that the Ge content in the aluminum alloy profile is 0.015%.

[0068] Comparative Example 3

[0069] The difference from Example 1 is that the Ge content in the aluminum alloy profile is 0.06%.

[0070] Comparative Example 4

[0071] The difference from Example 1 is that the aluminum alloy profile does not contain Ge, but contains 0.05% of Sc.

[0072] Comparative Example 5

[0073] The difference from Example 1 is that the aluminum alloy profile does not contain Ge, but contains 0.1% of Sc.

[0074] Comparative Example 6

[0075] The difference from Example 2 is that the Sc content in the aluminum alloy profile is 0.008%.

[0076] Comparative Example 7

[0077] The difference from Example 2 is that the Sc content in the aluminum alloy profile is 0.02%.

[0078] Test Example

[0079] The tensile strength, yield strength and elongation of the aluminum alloy profiles of the examples and the comparative examples were tested according to the standard GB / T 228.1-2021 “Metallic materials-tensile testing-Part 1: Method of test at room temperature”, and the results are shown in Table 1.

[0080] Table 1: Test results of tensile properties of aluminum alloy profiles

[0081]

[0082] As can be seen from the test results in Table 1, compared with Comparative Examples 1-3, Example 1 has higher tensile strength, yield strength and elongation, while Comparative Example 1 does not add Ge, and the Ge content in the aluminum alloy profiles of Comparative Example 2, Example 1 and Comparative Example 3 is 0.015%, 0.03% and 0.06% respectively. This is because Ge is a homologous element of Si, and an appropriate amount of Ge can replace part of Si to form a composite phase with higher density and better coherence with the matrix than Si, thereby improving the strength of the aluminum alloy. Less Ge has little effect and does not significantly improve the performance; while more Ge will form a segregated phase, resulting in a decrease in the elongation of the aluminum alloy profile. Compared with Example 1, Examples 2-4 and Comparative Examples 5-7 have higher tensile strength, yield strength and elongation, because Sc and Al can form nanoscale Al3Sc precipitates, which can refine the alloy and increase the strength, and the solubility of Sc is also low, which has the effect of solid solution strengthening and inhibiting recrystallization. Comparative Example 5, which does not contain Ge but contains 0.1% Sc, also exhibits good performance, but not as good as Example 3; and Comparative Example 4, which does not contain Ge but contains 0.1% Sc, does not significantly improve the performance, which shows that adding Sc alone needs to reach a certain content to have a good effect. These results also show that Ge and Sc have a certain synergistic effect, and the composite phase formed by Ge replacing part of Si forms a more stable structure with the Al3Sc precipitates, and optimizing the content of Ge and Sc can further optimize the structure.

[0083] The yield strength of the aluminum alloy profiles of the examples and the comparative examples was also tested after being kept at 200℃ for 1h, and the yield strength retention rate before and after keeping was calculated, and the results are shown in Table 2.

[0084] Table 2: Yield strength retention rate

[0085]

[0086] As can also be seen from the results in Table 2, Example 3 has the best temperature resistance.

[0087] The same section of the aluminum profiles of the examples and the comparative examples was tested for its absorbed energy during the three-point bending test, and the greater the absorbed energy per unit wall thickness of the material, the better the lightweight and impact resistance of the aluminum profile. The results are shown in Table 3.

[0088] Table 3 Absorbed energy results

[0089]

[0090] From the results of Table 3, it can also be seen that the preferred embodiment of the present application has the highest absorbed energy, indicating that the lightweighting and impact resistance are better under the same volume.

[0091] In summary, the present application optimizes the composition of the 6-series aluminum alloy, reduces the content of Fe and Zn, and introduces a small amount of Ge. Ge can replace part of Si, and compared to Si, forms a composite phase with higher density and better coherence with the matrix, thereby improving the strength of the aluminum alloy. In addition, Sc is also introduced, and Sc and Ge have a good synergistic effect with other elements, significantly improving the strength and toughness of the aluminum alloy.

[0092] Finally, it should be noted that: the above only for the preferred embodiments of the present application, and not for limiting the present application, although the foregoing embodiments of the present application have been described in detail, for those skilled in the art, it still can be modified to the technical solutions recorded in the foregoing embodiments, or equivalent replacement of some of the technical features, any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application, should be included in the protection scope of the present application.

Claims

1. A high strength aluminum alloy profile for a crash beam, characterized by, comprises, in mass percentage, Si: 0.42%~0.62%; Fe: 0.15%~0.30%; Cu: 0.18%~0.35%; Mn: ≤0.15%; Mg: 0.87%~1.07%; Cr: 0.06%~0.24%; Zn: ≤0.10%; Ti: 0.02%~0.14%; La-based rare earth: 0.05%~0.15%; Ge: 0.02%~0.05%; the balance being Al and inevitable impurities; comprises, in addition to Al and inevitable impurities, 0.01%~0.03% of Sc; the mass ratio of the Sc and Ge is 1:2~3.

2. A method of producing a high-strength aluminum alloy profile for a crash beam as claimed in claim 1, characterized in that, comprises, after the aluminum ingot is melted, Mn and Cr are added, then other raw materials except rare earth are added, and finally aluminum rare earth alloy is added for smelting, to obtain an aluminum alloy melt; the aluminum alloy melt is filtered to obtain an alloy liquid to be used; the alloy liquid to be used is cast into a blank; the blank is subjected to homogenization, extrusion forming, heat treatment, aging treatment and stretch straightening in sequence, to obtain a high-strength aluminum alloy profile for a crash beam.

3. The method of producing a high strength aluminum alloy profile for a crash beam according to claim 2, characterized by, the smelting temperature is 650~800℃; the homogenization is at 530~580℃ for 6~8h; the heat treatment temperature is 500~560℃.

4. The method of producing a high strength aluminum alloy profile for a crash beam according to claim 2, characterized by, the filtering is performed by using a two-stage ceramic filter plate, the mesh number of the two-stage ceramic filter plate being 30~40 mesh and 50~60 mesh respectively.

5. The method of producing a high strength aluminum alloy profile for a crash beam according to claim 2, characterized by, in the extrusion forming, the homogenized blank is heated to 500~560℃ at a temperature gradient of 6~8℃ / min, and then extrusion forming is performed by using an extrusion die at 460~500℃ and an extrusion speed of 4~6m / min.

6. The method of producing a high strength aluminum alloy profile for a crash beam according to claim 2, characterized by, the aging treatment is at 185±5℃ for 120~240min.

7. The method of producing a high strength aluminum alloy profile for a crash beam according to claim 2, characterized by, the stretch amount of the stretch straightening is 1%~5%.

8. The method of producing a high-strength aluminum alloy profile for a crash management beam according to any one of claims 2 to 7, characterized in that, the alloy liquid to be used is also allowed to stand at 660~770℃ for 0.5~2h before being cast into a blank.

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