Manufacturing process of aluminum alloy seamless tube for 35Mpa compressed hydrogen gas cylinder for vehicle

Abstract

The invention provides a manufacturing process of an aluminum alloy seamless tube for a 35Mpa compressed hydrogen gas cylinder for a vehicle, and relates to a manufacturing process of a large-diameter aluminum alloy seamless tube, in particular to a manufacturing process of the aluminum alloy seamless tube for the 35Mpa compressed hydrogen gas cylinder for the vehicle, which comprises the following steps of: selecting a hot-extruded finished aluminum tube as a raw material aluminum tube; the process comprises the following steps of: S1, extruding once; S11, inspecting a hot-extruded finished aluminum pipe serving as a raw material aluminum pipe; s12, ultrasonic flaw detection; s13, a lubricating agent is smeared; s14, drying is conducted; s15, adjusting technological parameters of the extruding machine; s16, the mold size is selected; s17, extruding for the first time; the material utilization rate of the aluminum alloy seamless tube for the 35Mpa compressed hydrogen gas cylinder for the vehicle is high, the production efficiency is remarkably improved, and the structure and the mechanical performance of the material are further improved by taking a hot extrusion finished product aluminum tube as a raw material aluminum tube and manufacturing the aluminum tube through the process.

Description

Technical Field

[0001] The invention relates to the technical field of large-diameter aluminum alloy seamless pipe manufacturing, and in particular to a manufacturing process of an aluminum alloy seamless pipe for a 35Mpa vehicle compressed hydrogen cylinder. Background Art

[0002] With the implementation of the "Medium- and Long-Term Plan for the Development of the Hydrogen Energy Industry (2021-2035)", the hydrogen energy industry will enter a period of rapid development in technology and industrialization. As a key storage device, 35Mpa vehicle compressed hydrogen cylinders will usher in new development opportunities. Guolian Securities analysis believes that 35Mpa vehicle compressed hydrogen cylinders are a type of hydrogen storage equipment with relatively mature technology and commercialization among the many hydrogen storage pressure equipment currently available, and will usher in a period of rapid development in the next 10 years. With the increase in production and sales of fuel cell vehicles, the demand for 35Mpa vehicle compressed hydrogen cylinders has increased significantly. In order to improve safety, mileage, etc., the market has also put forward higher requirements for the performance of 35Mpa vehicle compressed hydrogen cylinders. Therefore, the manufacturing process control of aluminum alloy seamless pipes used to manufacture 35Mpa vehicle compressed hydrogen cylinders is particularly important. The aluminum alloy seamless tube is a large-diameter thin-walled aluminum tube. Since the hot extrusion production process of the raw aluminum tube is limited, the straightness and ovality of the large-diameter thin-walled aluminum tube cannot be guaranteed. Therefore, the hot-extruded finished aluminum tube is reprocessed through the extrusion process. After plastic deformation, the geometric dimensions of the aluminum tube are changed to achieve the purpose of expanding the diameter of the aluminum tube and reducing the wall thickness of the aluminum tube, improving the straightness, ovality of the aluminum tube and the organization and mechanical properties of the material to meet the technical requirements. Summary of the invention

[0003] 1. Technical issues to be resolved In view of the shortcomings of the prior art, the present invention provides a manufacturing process for aluminum alloy seamless tubes for 35Mpa vehicle compressed hydrogen cylinders, which solves the problem that the straightness and ovality of large-diameter thin-walled aluminum tubes cannot be guaranteed due to the limitations of the hot extrusion production process of the raw aluminum tubes.

[0004] (II) Technical solution To achieve the above purpose, the present invention is implemented by the following technical scheme: a manufacturing process of aluminum alloy seamless pipe for 35Mpa vehicle compressed hydrogen cylinder, including the process steps of: Step S1: Extrusion S11. Inspect the hot extruded finished aluminum tube used as the raw aluminum tube; S12, ultrasonic flaw detection; S13, apply lubricant; S14, drying; S15, adjusting the extruder process parameters; S16, select the mold size; S17, first extrusion; S18, semi-finished product inspection; S19, annealing; Step S2, extrusion second step S21, applying lubricant; S22, drying; S23, adjusting the extruder process parameters; S24, select the mold size; S25, second extrusion; S26, semi-finished product inspection; S27, annealing; Step S3, extrusion three times: S31, apply lubricant; S32, drying; S33, adjusting the extruder process parameters; S34, select the mold size; S35, the third squeeze; S36, three-pass post-extrusion inspection; S37, ultrasonic flaw detection; S38, sawing; S39, inner and outer chamfers of the pipe mouth; S310, annealing; S311, inner surface grinding; S312, external surface polishing; S313, final product inspection; S314, spray marking on the outer surface.

[0005] Preferably: the extrusion process is: 内 371×17.5mm hot extruded finished aluminum tube is used as raw aluminum tube, extruded to Ø 内 457×16.5mm is used as the raw material aluminum tube for the second extrusion process. S11. Check the specifications Ø 内 The inner and outer surfaces, outer diameter, wall thickness, straightness and ovality of the 371×17.5mm hot extruded finished aluminum tube as the raw aluminum tube; S12. Perform ultrasonic flaw detection on each pipe according to the standard and complete the flaw detection on the surface of the pipe; S13, applying lubricant, the lubricant configuration requirement is: water: paraffin: soap powder = 10:1-3:3-5, and the lubrication effect is increased by applying the lubricant; S14, drying: using a drying device to evenly dry it by rotation, and the drying temperature is 80°C, and the drying time is: 2h, so that the lubricant on the inner surface solidifies; S15, adjusting the process parameters of the extruder: extrusion speed 15-17 cm / min; S16. Select the mold: Ø457mm, and clean the mold surface; S17, performing the first extrusion to extrude the pipe into shape; S18. Inspection of wall thickness, surface quality, ovality and straightness of semi-finished products; S19, Annealing: Annealing temperature 420±5℃, holding time 2h, HB hardness after annealing ≤40.

[0006] Optimum: The extrusion two-step process flow: 内 457×16.5mm one-pass extruded aluminum tube is used as the raw aluminum tube, and the second pass extrusion to Ø 内 520×16mm is used as the raw material aluminum tube for extrusion three times. S21. Apply lubricant. The lubricant configuration requirement is: water: paraffin: soap powder = 10:1-3:3-5; S22, drying: using a drying device to evenly dry it by rotation, and the drying temperature is: 80°C, the drying time is: 2h, so that the lubricant on the inner surface solidifies; S23, adjusting the process parameters of the extruder: extrusion speed 12-14 cm / min; S24. Select the mold: Ø520mm, and clean the mold surface; S25, performing a second extrusion to extrude the pipe again; S26, semi-finished product inspection wall thickness, surface quality, ovality, straightness; S27, Annealing: Annealing temperature 420±5℃, holding time 2h, HB hardness ≤40 after annealing.

[0007] Optimum: The three-step extrusion process: 内 520×16mm two-pass extruded aluminum tube is used as the raw aluminum tube, and three-pass extrusion to Ø 内 549×15.5mm, S31, apply lubricant, the lubricant configuration requirements are: water: paraffin: soap powder = 10:1~3:3~5; S32, drying: using a drying device to evenly dry it by rotation, and the drying temperature is: 80°C, the drying time is: 2h, so that the lubricant on the inner surface is solidified; S33, adjusting the process parameters of the extruder: extrusion speed 10-12 cm / min; S34, select the mold: Ø549mm, clean the mold surface; S35, performing the third extrusion, which can extrude the pipe for the third time, and the molding effect is better; S36, inspect wall thickness, surface quality, ovality and straightness after three extrusions; S37, conduct ultrasonic testing on each piece according to the standard; S38, Sawing, sawing slope ≤ 5mm, cut the pipe for easy assembly and use.

[0008] Preferred: S39, chamfer the inner and outer edges of the pipe mouth, and use a 60-mesh emery wheel and a polishing wheel to grind them in sequence to ensure that there are no burrs on the pipe mouth; S310, Annealing: Annealing temperature 350±5℃, holding time 25h, HB hardness after annealing ≤50; S311, inner surface grinding: use 60 mesh flap wheel to grind twice, 320 mesh flap wheel to grind twice, the inner surface roughness after grinding shall not exceed Ra2.0; S312, external surface polishing, manual inspection of surface quality and manual treatment of defects in the middle; S313. Final product inspection: internal and external surface quality, weight, length, wall thickness, ovality and straightness; S314, external surface spraying mark, the mark content includes product name, agreement number, brand, furnace number / batch number, specifications.

[0009] (III) Beneficial effects The present invention provides a manufacturing process of aluminum alloy seamless pipe for 35Mpa vehicle compressed hydrogen cylinder. It has the following beneficial effects: The present invention is manufactured according to the specification of the process Ø 内 The 549×15.5mm aluminum alloy seamless tube for 35Mpa vehicle compressed hydrogen cylinders has a high material utilization rate and significantly improved production efficiency. The hot-extruded finished aluminum tube is used as the raw aluminum tube through the manufacturing process to further improve the material's organization and mechanical properties, providing a safer guarantee for the manufacture of 35Mpa vehicle compressed hydrogen cylinders. DETAILED DESCRIPTION

[0010] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0011] Embodiment 1: The embodiment of the present invention provides a manufacturing process of an aluminum alloy seamless tube for a 35Mpa vehicle compressed hydrogen cylinder, comprising the following process steps: Step S1: Extrusion S11. Inspect the hot extruded finished aluminum tube used as the raw aluminum tube; S12, ultrasonic flaw detection; S13, apply lubricant; S14, drying; S15, adjusting the extruder process parameters; S16, select the mold size; S17, first extrusion; S18, semi-finished product inspection; S19, annealing; Step S2, extrusion second step S21, applying lubricant; S22, drying; S23, adjusting the extruder process parameters; S24, select the mold size; S25, second extrusion; S26, semi-finished product inspection; S27, annealing; Step S3, extrusion three times: S31, apply lubricant; S32, drying; S33, adjusting the extruder process parameters; S34, select the mold size; S35, the third squeeze; S36, three-pass post-extrusion inspection; S37, ultrasonic flaw detection; S38, sawing; S39, inner and outer chamfers of the pipe mouth; S310, annealing; S311, inner surface grinding; S312, external surface polishing; S313, final product inspection; S314, spray marking on the outer surface.

[0012] Extrusion process: Ø 内 371×17.5mm hot extruded finished aluminum tube is used as raw aluminum tube, extruded to Ø 内 457×16.5mm is used as the raw material aluminum tube for the second extrusion process. S11、Inspection SpecificationsØ 内 The inner and outer surfaces, outer diameter, wall thickness, straightness and ovality of the 371×17.5mm hot extruded finished aluminum tube as the raw aluminum tube; S12. Perform ultrasonic flaw detection on each pipe according to the standard and complete the flaw detection on the surface of the pipe; S13, applying lubricant, the lubricant configuration requirement is: water: paraffin: soap powder = 10:1-3:3-5, and the lubrication effect is increased by applying the lubricant; S14, drying: using a drying device to evenly dry it by rotation, and the drying temperature is 80°C, and the drying time is: 2h, so that the lubricant on the inner surface solidifies; S15, adjusting the process parameters of the extruder: extrusion speed 15-17 cm / min; S16. Select the mold: Ø457mm, and clean the mold surface; S17, performing the first extrusion; S18. Inspection of wall thickness, surface quality, ovality and straightness of semi-finished products; S19, Annealing: Annealing temperature 420±5℃, holding time 2h, HB hardness after annealing ≤40.

[0013] Extrusion secondary process flow: 内 457×16.5mm one-pass extruded aluminum tube is used as the raw aluminum tube, and the second pass extrusion to Ø 内 520×16mm is used as the raw material aluminum tube for extrusion three times. S21. Apply lubricant. The lubricant configuration requirement is: water: paraffin: soap powder = 10:1-3:3-5; S22, drying: using a drying device to evenly dry it by rotation, and the drying temperature is: 80°C, the drying time is: 2h, so that the lubricant on the inner surface solidifies; S23, adjusting the process parameters of the extruder: extrusion speed 12-14 cm / min; S24. Select the mold: Ø520mm, and clean the mold surface; S25, performing a second extrusion; S26, semi-finished product inspection wall thickness, surface quality, ovality, straightness; S27, Annealing: Annealing temperature 420±5℃, holding time 2h, HB hardness ≤40 after annealing.

[0014] Extrusion three-step process: 内 520×16mm two-pass extruded aluminum tube is used as the raw aluminum tube, and three-pass extrusion to Ø 内 549×15.5mm, S31, apply lubricant, the lubricant configuration requirements are: water: paraffin: soap powder = 10:1~3:3~5; S32, drying: using a drying device to evenly dry it by rotation, and the drying temperature is: 80°C, the drying time is: 2h, so that the lubricant on the inner surface is solidified; S33, adjusting the process parameters of the extruder: extrusion speed 10-12 cm / min; S34, select the mold: Ø549mm, clean the mold surface; S35, performing the third extrusion; S36, inspect wall thickness, surface quality, ovality and straightness after three extrusions; S37, conduct ultrasonic testing on each piece according to the standard; S38, Sawing, sawing slope ≤ 5mm, cut the pipe for easy assembly and use.

[0015] S39, chamfer the inner and outer edges of the pipe mouth, and use a 60-mesh emery wheel and a polishing wheel to grind them in sequence to ensure that there are no burrs on the pipe mouth; S310, Annealing: Annealing temperature 350±5℃, holding time 25h, HB hardness after annealing ≤50; S311, inner surface grinding: use 60 mesh flap wheel to grind twice, 320 mesh flap wheel to grind twice, the inner surface roughness after grinding shall not exceed Ra2.0; S312, external surface polishing, manual inspection of surface quality and manual treatment of defects in the middle; S313. Final product inspection: internal and external surface quality, weight, length, wall thickness, ovality and straightness; S314, external surface spraying mark, the mark content includes product name, agreement number, brand, furnace number / batch number, specifications.

[0016] Embodiment 2: The difference from the first embodiment is that the process steps include: Step S1: Extrusion S11. Inspect the hot extruded finished aluminum tube used as the raw aluminum tube; S12, ultrasonic flaw detection; S13, apply lubricant; S14, drying; S15, adjusting the extruder process parameters; S16, select the mold size; S17, first extrusion; S18, semi-finished product inspection; S19, annealing; Step S2, extrusion second step S21, applying lubricant; S22, drying; S23, adjusting the extruder process parameters; S24, select the mold size; S25, second extrusion; S26, semi-finished product inspection; S27, annealing; Step S3, extrusion three times: S31, apply lubricant; S32, drying; S33, adjusting the extruder process parameters; S34, select the mold size; S35, the third squeeze; S36, three-pass post-extrusion inspection; S37, ultrasonic flaw detection; S38, sawing; S39, inner and outer chamfers of the pipe mouth; S310, annealing; S311, inner surface grinding; S312, external surface polishing; S313, final product inspection; S314, spray marking on the outer surface.

[0017] Extrusion process: Ø 内 371×17.5mm hot extruded finished aluminum tube is used as raw aluminum tube, extruded to Ø 内 457×16.5mm is used as the raw material aluminum tube for the second extrusion process. S11、Inspection SpecificationsØ 内 The inner and outer surfaces, outer diameter, wall thickness, straightness and ovality of the 371×17.5mm hot extruded finished aluminum tube as the raw aluminum tube; S12. Perform ultrasonic flaw detection on each pipe according to the standard and complete the flaw detection on the surface of the pipe; S13, applying lubricant, the lubricant configuration requirement is: water: paraffin: soap powder = 10:1-3:3-5, and the lubrication effect is increased by applying the lubricant; S14, drying: using a drying device to evenly dry it by rotation, and the drying temperature is 80°C, and the drying time is: 2h, so that the lubricant on the inner surface solidifies; S15, adjusting the process parameters of the extruder: extrusion speed 15-17 cm / min; S16. Select the mold: Ø457mm, and clean the mold surface; S17, performing the first extrusion; S18. Inspection of wall thickness, surface quality, ovality and straightness of semi-finished products; S19, Annealing: Annealing temperature 420±5℃, holding time 2h, HB hardness after annealing ≤40.

[0018] Extrusion secondary process flow: 内 457×16.5mm one-pass extruded aluminum tube is used as the raw aluminum tube, and the second pass extrusion to Ø 内 520×16mm is used as the raw material aluminum tube for extrusion three times. S21. Apply lubricant. The lubricant configuration requirement is: water: paraffin: soap powder = 10:1-3:3-5; S22, drying: using a drying device to evenly dry it by rotation, and the drying temperature is: 80°C, the drying time is: 2h, so that the lubricant on the inner surface solidifies; S23, adjusting the process parameters of the extruder: extrusion speed 12-14 cm / min; S24. Select the mold: Ø520mm, and clean the mold surface; S25, performing a second extrusion; S26, semi-finished product inspection wall thickness, surface quality, ovality, straightness; S27, Annealing: Annealing temperature 420±5℃, holding time 2h, HB hardness ≤40 after annealing.

[0019] According to the above process, the physical and chemical tests of aluminum alloy seamless pipe (material 6061) are shown in the following table: (Table 1) Chemical composition, analysis method is in accordance with GB / T20975: meet the requirements of the following table (wt)% It should meet the following requirements: Liquid hydrogen measurement ≤ 0.15ml / 100gAl.

[0020] The mechanical properties are shown in the following table. The room temperature tensile test method is carried out in accordance with the provisions of GB / T228: (Table 2) Mechanical properties The macrostructure is shown in the following table. The inspection method is in accordance with the provisions of GB / T 3246.2: (Table 3) Low-magnification tissue Microstructure: It should meet the requirements of GB / T4437.1. Overburned structure is not allowed. The inspection method shall be carried out in accordance with the provisions of GB / T3246.1.

[0021] The above description is only an embodiment of the present invention and does not limit the protection scope of the present invention.

[0022] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A manufacturing process of aluminum alloy seamless pipe for 35Mpa vehicle compressed hydrogen cylinder, characterized by: The process steps include: Step S1: Extrusion S11. Inspect the hot extruded finished aluminum tube used as the raw aluminum tube; S12, ultrasonic flaw detection; S13, apply lubricant; S14, drying; S15, adjusting the extruder process parameters; S16, select the mold size; S17, first extrusion; S18, semi-finished product inspection; S19, annealing; Step S2, extrusion second step S21, applying lubricant; S22, drying; S23, adjusting the extruder process parameters; S24, select the mold size; S25, second extrusion; S26, semi-finished product inspection; S27, annealing; Step S3, extrusion three times: S31, apply lubricant; S32, drying; S33, adjusting the extruder process parameters; S34, select the mold size; S35, the third squeeze; S36, three-pass post-extrusion inspection; S37, ultrasonic flaw detection; S38, sawing; S39, inner and outer chamfers of the pipe mouth; S310, annealing; S311, inner surface grinding; S312, external surface polishing; S313, final product inspection; S314, spray marking on the outer surface.

2. The manufacturing process of a 35Mpa aluminum alloy seamless pipe for a vehicle compressed hydrogen cylinder according to claim 1, characterized in that: The extrusion process consists of: 内 371×17.5mm hot extruded finished aluminum tube is used as raw aluminum tube, extruded to Ø 内 457×16.5mm is used as the raw material aluminum tube for the second extrusion process. S11. Check the specifications Ø 内 The inner and outer surfaces, outer diameter, wall thickness, straightness and ovality of the 371×17.5mm hot extruded finished aluminum tube as the raw aluminum tube; S12. Perform ultrasonic flaw detection on each pipe according to the standard and complete the flaw detection on the surface of the pipe; S13, applying lubricant, the lubricant configuration requirement is: water: paraffin: soap powder = 10:1-3:3-5, and the lubrication effect is increased by applying the lubricant; S14, drying: using a drying device to evenly dry it by rotation, and the drying temperature is 80°C, and the drying time is: 2h, so that the lubricant on the inner surface solidifies; S15, adjusting the process parameters of the extruder: extrusion speed 15-17 cm / min; S16. Select the mold: Ø457mm, and clean the mold surface; S17, performing the first extrusion to extrude the pipe into shape; S18. Inspection of wall thickness, surface quality, ovality and straightness of semi-finished products; S19, Annealing: Annealing temperature 420±5℃, holding time 2h, HB hardness after annealing ≤40.

3. The manufacturing process of a 35Mpa aluminum alloy seamless pipe for a vehicle compressed hydrogen cylinder according to claim 1, characterized in that: The second extrusion process flow: 内 457×16.5mm one-pass extruded aluminum tube is used as the raw aluminum tube, and the second pass extrusion to Ø 内 520×16mm is used as the raw material aluminum tube for extrusion three times. S21. Apply lubricant. The lubricant configuration requirement is: water: paraffin: soap powder = 10:1-3:3-5; S22, drying: using a drying device to evenly dry it by rotation, and the drying temperature is: 80°C, the drying time is: 2h, so that the lubricant on the inner surface solidifies; S23, adjusting the process parameters of the extruder: extrusion speed 12-14 cm / min; S24. Select the mold: Ø520mm, and clean the mold surface; S25, performing a second extrusion; S26, semi-finished product inspection wall thickness, surface quality, ovality, straightness; S27, Annealing: Annealing temperature 420±5℃, holding time 2h, HB hardness ≤40 after annealing.

4. The manufacturing process of a 35Mpa aluminum alloy seamless pipe for a vehicle compressed hydrogen cylinder according to claim 1, characterized in that: The three-step extrusion process: 内 520×16mm two-pass extruded aluminum tube is used as the raw aluminum tube, and three-pass extrusion to Ø 内 549×15.5mm, S31, apply lubricant, the lubricant configuration requirements are: water: paraffin: soap powder = 10:1~3:3~5; S32, drying: using a drying device to evenly dry it by rotation, and the drying temperature is: 80°C, the drying time is: 2h, so that the lubricant on the inner surface is solidified; S33, adjusting the process parameters of the extruder: extrusion speed 10-12 cm / min; S34, select the mold: Ø549mm, clean the mold surface; S35, performing a third extrusion to extrude the pipe again; S36, inspect wall thickness, surface quality, ovality and straightness after three extrusions; S37, conduct ultrasonic flaw detection on each piece according to the standard; S38, Sawing, sawing slope ≤ 5mm, cut the pipe for easy assembly and use.

5. The manufacturing process of a 35Mpa aluminum alloy seamless pipe for a vehicle compressed hydrogen cylinder according to claim 4, characterized in that: S39, chamfer the inner and outer edges of the pipe mouth, and use a 60-mesh emery wheel and a polishing wheel to grind them in sequence to ensure that there are no burrs on the pipe mouth; S310, Annealing: Annealing temperature 350±5℃, holding time 25h, HB hardness after annealing ≤50; S311, inner surface grinding: use 60 mesh flap wheel to grind twice, 320 mesh flap wheel to grind twice, the inner surface roughness after grinding shall not exceed Ra2.0; S312, external surface polishing, manual inspection of surface quality and manual treatment of defects in the middle; S313. Final product inspection: internal and external surface quality, weight, length, wall thickness, ovality and straightness; S314, external surface spraying mark, the mark content includes product name, agreement number, brand, furnace number / batch number, specifications.

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