Preparation method of high-strength bendable aluminum alloy guide rail

Abstract

The invention discloses a preparation method of a high-strength bendable aluminum alloy guide rail, and belongs to the field of aluminum alloy material preparation. After the components and the process parameters are optimized, the grain size structure of a casting rod reaches the first level, impurity elements are effectively reduced, grains grow up due to energy accumulation in the extrusion process, enough energy can be generated in the extrusion process, the structure is completely recrystallized, the grain structure is an equiaxed grain structure with the size being 150 micrometers, and the grain size is larger than or equal to 100 micrometers. And precipitation and growth of a second phase and generation of a crack source are reduced, and the ductility of a product is improved. In addition, by adding the refining agent with a specific proportion and components, rapid melting dispersion can be achieved, active hydrogen in the high-temperature molten aluminum can be effectively removed, impurities can be carried to the surface of the molten aluminum alloy under the action of buoyancy, deslagging is facilitated, and the quality of the prepared aluminum alloy guide rail is further improved.

Description

Technical Field

[0001] The invention relates to the field of aluminum alloy preparation, and in particular to a method for preparing a high-strength bendable aluminum alloy guide rail. Background Art

[0002] Aluminum has the advantages of low density, high strength, and good formability, so its application areas are constantly increasing. Due to the diversity of usage scenarios, there are different requirements for the cross-section and shape of aluminum. For example, guide rail products are also widely used in rail transportation, industrial and building hoisting, and industrial equipment. Aluminum alloy guide rails are a common guide rail. At present, most of the aluminum alloy guide rails are focused on product structure and welding methods. For example, the Chinese patent number CN201410849136.X discloses an aluminum alloy guide rail and its welding method. For example, the patent number CN202110671150.5 discloses an aluminum alloy guide rail, but the bending performance is poor.

[0003] In the prior art, different cross-sections can be designed according to different use requirements, and the required products can be extruded by forward extrusion. However, the guide rail profiles obtained by extrusion in the prior art are generally straight and have limited applicability. When in use, some guide rails that need to bend need to be bent and then spliced. Since the strength of aluminum alloy is high after aging, the elongation will decrease synchronously. Bending after aging is prone to breakage, and it will also affect production efficiency. Summary of the invention

[0004] Based on this, in order to solve the problems of low strength, decreased elongation and low production efficiency of aluminum alloy guide rails in the prior art, the present invention provides a method for preparing a high-strength bendable aluminum alloy guide rail, and the specific technical scheme is as follows:

[0005] A method for preparing a high-strength bendable aluminum alloy guide rail, the method comprising the following steps:

[0006] The raw materials of the aluminum alloy guide rail are prepared and put into a smelting furnace for smelting to obtain alloy liquid;

[0007] Adding a refining agent to the alloy liquid and blowing it evenly to the bottom of the furnace under an argon atmosphere, with a single refining time of not less than 20 minutes, removing hydrogen online so that the hydrogen content in the furnace is ≤0.25mL / 100gAl, then performing double-stage filtration, and then casting to obtain a cast rod;

[0008] The cast rod is homogenized, extruded, and then cooled in water to below 50° C. within 1 minute;

[0009] After cooling, aging treatment and bending treatment are carried out to obtain aluminum alloy guide rails;

[0010] The temperature of the extrusion treated rod is controlled at 490°C to 510°C, the outlet temperature is controlled at 530°C to 550°C, the extrusion ratio is 40 to 50, the extrusion speed is 8 mm / s to 10 mm / s, and the extrusion treatment controls the cast rod to have an equiaxed crystalline structure with a size of ≤150 μm, and the coarse grain layer is controlled within 0.2 mm.

[0011] Furthermore, the raw material includes the following chemical composition: Si: 0.60% to 0.65%, Mg: 0.48% to 0.53%, Fe: ≤0.15%, Ti: ≤0.02%, the impurity content is ≤0.03% individually, and the balance is Al.

[0012] Furthermore, the refining agent is prepared from sodium chloride, potassium oxalate and manganese phosphide in a mass ratio of (1-3): (1-5): (1-2).

[0013] Furthermore, the amount of the refining agent added accounts for 0.25% to 0.75% of the mass of the aluminum alloy liquid.

[0014] Furthermore, the online dehydrogenation adopts a double-rotor degassing box, and the hydrogen content at the end of the disk is ≤0.18mL / 100gAl.

[0015] Furthermore, the double-stage filtration adopts double-stage filtration, the first-stage filtration uses a 40p foam ceramic filter plate, and the second-stage filtration uses a 60p foam ceramic filter plate.

[0016] Furthermore, the casting temperature is 700° C. to 720° C., and the casting speed is 180 mm / min to 250 mm / min.

[0017] Furthermore, the temperature of the homogenization treatment is 550° C. to 570° C., and the time is 6 h to 9 h.

[0018] Furthermore, the aging treatment is a two-stage aging heat treatment, wherein the temperature of the first-stage aging treatment is 120°C to 150°C, the time is 1h to 3h, and the temperature of the second-stage aging treatment is 180°C to 220°C, the time is 10h to 12h.

[0019] Furthermore, the hardness of the aluminum alloy guide rail reaches 16HW, the tensile strength is ≥300MPa, the yield strength is ≥280MPa, and the elongation is ≥12%.

[0020] After optimizing the composition and process parameters in the above scheme, the grain size of the cast rod reaches level 1, effectively reducing the generation of impurity elements. During the extrusion process, the energy concentration causes the grains to grow, and sufficient energy can be generated during the extrusion process to completely recrystallize the organization. The grain structure presents an equiaxed grain structure of 150μm in size, and reduces the precipitation and growth of the second phase, which generates crack sources and improves the elongation of the product. In addition, by adding a refining agent with a specific proportion and composition, it can quickly melt and disperse, effectively remove active hydrogen in high-temperature aluminum liquid, carry impurities to the surface of aluminum alloy liquid under the action of buoyancy, facilitate slag discharge, and further improve the quality of aluminum alloy guide rails. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the product after bending in Example 1;

[0022] Figure 2 This is a schematic diagram of the internal structure of the aluminum alloy guide rail prepared in Example 1 of the present invention after extrusion treatment. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with its embodiments. It should be understood that the specific implementation methods described herein are only used to explain the present invention and do not limit the protection scope of the present invention.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0025] A method for preparing a high-strength bendable aluminum alloy guide rail in one embodiment of the present invention comprises the following steps:

[0026] The raw materials of the aluminum alloy guide rail are prepared and put into a smelting furnace for smelting to obtain alloy liquid;

[0027] Adding a refining agent to the alloy liquid and blowing it evenly to the bottom of the furnace under an argon atmosphere, with a single refining time of not less than 20 minutes, removing hydrogen online so that the hydrogen content in the furnace is ≤0.25mL / 100gAl, then performing double-stage filtration, and then casting to obtain a cast rod;

[0028] The cast rod is homogenized, extruded, and then cooled in water to below 50° C. within 1 minute;

[0029] After cooling, aging treatment and bending treatment are carried out to obtain aluminum alloy guide rails;

[0030] The temperature of the extrusion treated rod is controlled at 490°C to 510°C, the outlet temperature is controlled at 530°C to 550°C, the extrusion ratio is 40 to 50, the extrusion speed is 8 mm / s to 10 mm / s, and the extrusion treatment controls the cast rod to have an equiaxed crystalline structure with a size of ≤150 μm, and the coarse grain layer is controlled within 0.2 mm.

[0031] In one of the embodiments, the raw material includes the following chemical composition: Si: 0.60% to 0.65%, Mg: 0.48% to 0.53%, Fe: ≤0.15%, Ti: ≤0.02%, the impurity content is ≤0.03% individually, and the balance is Al.

[0032] In one embodiment, the refining agent is prepared from sodium chloride, potassium oxalate and manganese phosphide in a mass ratio of (1-3):(1-5):(1-2).

[0033] In one embodiment, the preparation method of the refining agent is: sodium chloride, potassium oxalate and manganese phosphide are mixed, ball-milled for 10 to 20 minutes, treated at 800°C to 1000°C for 1 to 2 hours, cooled, crushed and ball-milled to obtain the refining agent.

[0034] In one embodiment, the amount of the refining agent added is 0.25% to 0.75% of the mass of the aluminum alloy liquid.

[0035] In one embodiment, the online dehydrogenation uses a double-rotor degassing box, and the hydrogen content at the end of the disk is ≤0.18mL / 100gAl.

[0036] In one embodiment, the double-stage filtration adopts double-stage filtration, the first-stage filtration uses a 40p foam ceramic filter plate, and the second-stage filtration uses a 60p foam ceramic filter plate.

[0037] In one embodiment, the casting temperature is 700° C. to 720° C., and the casting speed is 180 mm / min to 250 mm / min.

[0038] In one embodiment, the homogenization treatment is carried out at a temperature of 550° C. to 570° C. and for a time of 6 h to 9 h.

[0039] In one embodiment, the aging treatment is a two-stage aging heat treatment, wherein the temperature of the first-stage aging treatment is 120°C to 150°C, the time is 1h to 3h, and the temperature of the second-stage aging treatment is 180°C to 220°C, the time is 10h to 12h.

[0040] In one embodiment, the aluminum alloy guide rail has a hardness of 16 HW, a tensile strength of ≥300 MPa, a yield strength of ≥280 MPa, and an elongation of ≥12%.

[0041] After optimizing the composition and process parameters in the above scheme, the grain size of the cast rod reaches level 1, effectively reducing the generation of impurity elements. During the extrusion process, the energy concentration causes the grains to grow, and sufficient energy can be generated during the extrusion process to completely recrystallize the organization. The grain structure presents an equiaxed grain structure of 150μm in size, and reduces the precipitation and growth of the second phase, which generates crack sources and improves the elongation of the product. In addition, by adding a refining agent with a specific proportion and composition, it can quickly melt and disperse, effectively remove active hydrogen in high-temperature aluminum liquid, carry impurities to the surface of aluminum alloy liquid under the action of buoyancy, facilitate slag discharge, and further improve the quality of aluminum alloy guide rails.

[0042] The embodiments of the present invention will be described in detail below with reference to specific examples.

[0043] Embodiment 1:

[0044] A method for preparing a high-strength bendable aluminum alloy guide rail comprises the following steps:

[0045] The raw materials of the aluminum alloy guide rail are prepared, and the raw materials include the following chemical components: Si: 0.60%, Mg: 0.53%, Fe: 0.12%, Ti: 0.01%, the impurity content is ≤ 0.03% each, and the balance is Al, and are put into a smelting furnace for smelting to obtain a molten alloy;

[0046] Sodium chloride, potassium oxalate and manganese phosphide are mixed in a mass ratio of 1:5:1, ball-milled for 10 minutes, and then treated at 800°C for 1 hour. After cooling, crushing and ball-milling, a refining agent is obtained, and then 0.55% of the refining agent by mass of the aluminum alloy liquid is added to the alloy liquid and evenly blown to the bottom of the furnace under an argon atmosphere, and the single refining time is not less than 20 minutes;

[0047] Online dehydrogenation uses a dual-rotor degassing box, followed by two-stage filtration, with a 40p foam ceramic filter plate for the first stage and a 60p foam ceramic filter plate for the second stage;

[0048] Casting is performed at a temperature of 710°C and a casting speed of 200 mm / min to obtain a cast rod;

[0049] The cast rod is homogenized at a temperature of 550° C. for 8 hours, extruded and the rod temperature is controlled at 490° C., the outlet temperature is controlled at 530° C., the extrusion ratio is 40, the extrusion speed is 8 mm / s, and the cast rod is controlled by the extrusion process to have an equiaxed crystal structure with a size of ≤150 μm, the coarse grain layer is controlled within 0.2 mm, and water-cooled and cooled to below 50° C. within 1 minute;

[0050] A double-stage aging heat treatment is performed, wherein the primary aging treatment temperature is 120°C for 1 hour, and the secondary aging treatment temperature is 200°C for 10 hours. Bending treatment is performed to obtain an aluminum alloy guide rail.

[0051] Embodiment 2:

[0052] A method for preparing a high-strength bendable aluminum alloy guide rail comprises the following steps:

[0053] The raw materials of the aluminum alloy guide rail are prepared, and the raw materials include the following chemical components: Si: 0.62%, Mg: 0.50%, Fe: 0.10%, Ti: 0.01%, the impurity content is ≤ 0.03% each, and the balance is Al, and are put into a smelting furnace for smelting to obtain a molten alloy;

[0054] Sodium chloride, potassium oxalate and manganese phosphide are mixed in a mass ratio of 3:3:1, ball-milled for 15 minutes, and then treated at 900°C for 1 hour. After cooling, crushing and ball-milling, a refining agent is obtained, and then a refining agent accounting for 0.60% of the mass of the aluminum alloy liquid is added to the alloy liquid and evenly blown to the bottom of the furnace under an argon atmosphere, and a single refining time is not less than 20 minutes;

[0055] Online dehydrogenation uses a dual-rotor degassing box, followed by two-stage filtration, with a 40p foam ceramic filter plate for the first stage and a 60p foam ceramic filter plate for the second stage;

[0056] Casting is performed at a temperature of 720°C and a casting speed of 220 mm / min to obtain a cast rod;

[0057] The cast rod is homogenized at a temperature of 570° C. for 7 hours, extruded and the rod temperature is controlled at 500° C., the outlet temperature is controlled at 550° C., the extrusion ratio is 40, the extrusion speed is 8 mm / s, and the cast rod is controlled by the extrusion process to have an equiaxed crystal structure with a size of ≤150 μm, the coarse grain layer is controlled within 0.2 mm, and water-cooled and cooled to below 50° C. within 1 minute;

[0058] A double-stage aging heat treatment is performed, wherein the primary aging treatment temperature is 120°C for 1 hour, and the secondary aging treatment temperature is 220°C for 10 hours. Bending treatment is performed to obtain an aluminum alloy guide rail.

[0059] Embodiment 3:

[0060] A method for preparing a high-strength bendable aluminum alloy guide rail comprises the following steps:

[0061] The raw materials of the aluminum alloy guide rail are prepared according to the following chemical composition: Si: 0.65%, Mg: 0.48%, Fe: 0.11%, Ti: 0.01%, the impurity content is ≤ 0.03% each, and the balance is Al, and are put into a smelting furnace for smelting to obtain a molten alloy;

[0062] Sodium chloride, potassium oxalate and manganese phosphide are mixed in a mass ratio of 2:3:2, ball-milled for 20 minutes, and then treated at 1000°C for 2 hours. After cooling, crushing and ball-milling, a refining agent is obtained, and then a refining agent accounting for 0.72% of the mass of the aluminum alloy liquid is added to the alloy liquid and evenly blown to the bottom of the furnace under an argon atmosphere, and a single refining time is not less than 20 minutes;

[0063] Online dehydrogenation uses a dual-rotor degassing box, followed by two-stage filtration, with a 40p foam ceramic filter plate for the first stage and a 60p foam ceramic filter plate for the second stage;

[0064] Casting is performed at a temperature of 720° C. and a casting speed of 200 mm / min to obtain a cast rod;

[0065] The cast rod is homogenized at a temperature of 570° C. for 6 hours, and the extrusion treatment is performed. The temperature of the extruded rod is controlled at 500° C., the outlet temperature is controlled at 550° C., the extrusion ratio is 40, the extrusion speed is 8 mm / s, and the extrusion treatment controls the cast rod to have an equiaxed crystalline structure with a size of ≤150 μm, the coarse grain layer is controlled within 0.2 mm, and the rod is cooled by water and cooled to below 50° C. within 1 minute;

[0066] A double-stage aging heat treatment is performed, wherein the primary aging treatment temperature is 125°C for 1.5 h, and the secondary aging treatment temperature is 200°C for 10 h. Bending treatment is performed to obtain an aluminum alloy guide rail.

[0067] Comparative Example 1:

[0068] The difference between Comparative Example 1 and Example 3 is that the chemical composition of the raw materials in Comparative Example 1 is as follows: Si: 0.79%, Mg: 0.1%, Fe: 0.3%, Ti: 0.8%, the impurity content is ≤ 0.03% each, and the balance is Al. The rest is the same as Example 3.

[0069] Comparative Example 2:

[0070] The difference between Comparative Example 2 and Example 3 is that in Comparative Example 2, a single component of sodium chloride is used as a refining agent, and the rest is the same as Example 3.

[0071] Comparative Example 3:

[0072] The difference between Comparative Example 3 and Example 3 is that in Comparative Example 3, a single component of potassium oxalate is used as a refining agent, and the rest is the same as Example 3.

[0073] Comparative Example 4:

[0074] The difference between Comparative Example 4 and Example 3 is that in Comparative Example 4, a single manganese phosphide is used as a refining agent, and the rest is the same as Example 3.

[0075] Comparative Example 5:

[0076] The difference between Comparative Example 5 and Example 3 is that the mass ratio of sodium chloride, potassium oxalate and manganese phosphide in Comparative Example 5 is 1:1:5, and the others are the same as Example 3.

[0077] Comparative Example 6:

[0078] The difference between Comparative Example 6 and Example 3 is that in Comparative Example 6, the temperature of the extrusion treatment is controlled to 420° C., the outlet temperature is controlled to 500° C., the extrusion ratio is 35, and the others are the same as Example 3.

[0079] Comparative Example 7:

[0080] The difference between Comparative Example 7 and Example 3 is that the temperature of the aging treatment in Comparative Example 7 is 250° C. and the time is 8 h, and the others are the same as Example 3.

[0081] The performance tests of Examples 1 to 3 and Comparative Examples 1 to 7 were carried out with reference to GB / T32186-2015. The purity of the aluminum alloy liquid after refining is shown in Table 1 below.

[0082] Table 1: Purity of aluminum alloy liquid after refining

[0083]

[0084] It can be seen from the data in Table 1 that after refining, the present application obtains a very pure aluminum alloy liquid that meets the test standard. Mixing sodium chloride, potassium oxalate and manganese phosphide in a certain mass ratio can achieve a more significant purification effect and help improve the quality of the aluminum alloy liquid.

[0085] The aluminum alloy guide rail samples prepared in Examples 1 to 3 and the aluminum alloy guide rail comparison samples prepared in Comparative Examples 1 to 7 were subjected to performance tests, and the results are shown in Table 2 below.

[0086]

[0087]

[0088] From the data analysis of Table 2, it can be seen that after aging treatment, the aluminum alloy guide rail prepared in this application has a hardness of more than 16HW, a tensile strength of ≥300MPa, a yield strength of ≥280MPa, and an elongation of ≥12%, showing excellent mechanical strength as a whole.

[0089] in addition, Figure 1 This is a schematic diagram of the product after bending in Example 1. Figure 1 It can be seen that the aluminum alloy guide rail obtained in the present application has excellent bending effect and can be used without excessive processing, has higher production effect, and has a low scrap rate. Figure 2 This is a schematic diagram of the internal structure of the aluminum alloy guide rail prepared in Example 1 of the present invention after extrusion treatment, which presents an equiaxed crystalline structure with the coarse grain layer controlled within 0.2 mm. The aluminum alloy guide rails obtained in Examples 2 and 3 are the same as those in Example 1 and will not be described again here.

[0090] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0091] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a high-strength bendable aluminum alloy guide rail, characterized in that: The preparation method comprises the following steps: The raw materials of the aluminum alloy guide rail are prepared and put into a smelting furnace for smelting to obtain alloy liquid; Adding a refining agent to the alloy liquid and blowing it evenly to the bottom of the furnace under an argon atmosphere, with a single refining time of not less than 20 minutes, removing hydrogen online so that the hydrogen content in the furnace is ≤0.25mL / 100gAl, then performing double-stage filtration, and then casting to obtain a cast rod; The cast rod is homogenized, extruded, and then cooled in water to below 50° C. within 1 minute; After cooling, aging treatment and bending treatment are carried out to obtain aluminum alloy guide rails; The temperature of the extrusion treated rod is controlled at 490°C to 510°C, the outlet temperature is controlled at 530°C to 550°C, the extrusion ratio is 40 to 50, the extrusion speed is 8 mm / s to 10 mm / s, and the extrusion treatment controls the cast rod to have an equiaxed crystalline structure with a size of ≤150 μm, and the coarse grain layer is controlled within 0.2 mm.

2. The preparation method according to claim 1, characterized in that: The raw material includes the following chemical components: Si: 0.60% to 0.65%, Mg: 0.48% to 0.53%, Fe: ≤0.15%, Ti: ≤0.02%, the impurity content is ≤0.03% each, and the balance is Al.

3. The preparation method according to claim 1, characterized in that: The refining agent is prepared from sodium chloride, potassium oxalate and manganese phosphide in a mass ratio of (1-3): (1-5): (1-2).

4. The preparation method according to claim 3, characterized in that: The added amount of the refining agent accounts for 0.25% to 0.75% of the mass of the aluminum alloy liquid.

5. The preparation method according to claim 1, characterized in that: The online dehydrogenation adopts a double-rotor degassing box, and the hydrogen content at the end of the disk is ≤0.18mL / 100gAl.

6. The preparation method according to claim 1, characterized in that: The double-stage filtration adopts double-stage filtration, the first-stage filtration uses a 40p foam ceramic filter plate, and the second-stage filtration uses a 60p foam ceramic filter plate.

7. The preparation method according to claim 1, characterized in that: The casting temperature is 700° C. to 720° C., and the casting speed is 180 mm / min to 250 mm / min.

8. The preparation method according to claim 1, characterized in that: The temperature of the homogenization treatment is 550° C. to 570° C., and the time is 6 h to 9 h.

9. The preparation method according to claim 1, characterized in that: The aging treatment is a two-stage aging heat treatment, wherein the temperature of the first-stage aging treatment is 120°C to 150°C, the time is 1h to 3h, and the temperature of the second-stage aging treatment is 180°C to 220°C, the time is 10h to 12h.

10. The preparation method according to claim 9, characterized in that: The hardness of the aluminum alloy guide rail reaches 16HW, the tensile strength is ≥300MPa, the yield strength is ≥280MPa, and the elongation is ≥12%.

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