Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C23/00—Extruding metal; Impact extrusion
  • B21C23/002—Extruding materials of special alloys so far as the composition of the alloy requires or permits special extruding methods of sequences
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
  • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
  • C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
  • C22F1/053—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with zinc as the next major constituent
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
  • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
  • C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
  • C22F1/057—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with copper as the next major constituent

Definitions

• the present invention relates to a process for spinning high-strength aluminum alloys to manufacture bars, tubes or profiles.
• high strength aluminum alloys alloys making it possible to obtain, after working and heat treatment, a breaking strength greater than 350 MPa, in particular AI-Cu-Mg alloys (Cu> 3% , Mg > 0.5%), of which the best known are 2014, 2017 A, 2030, and 2024, and AI-Zn-Mg-Cu alloys, the best known of which is 7075, according to the designations of French standard AFNOR NF A - 02-104.
• French patent 2,273,077 reports the spinning of soft alloys of the 6000 series, at speeds of the order of 20 m / minute and spinning ratios exceeding 100. It should however be noted that the direct jacketed spinning of the alloys with high resistance is usually done at fairly low speeds, of the order of 2 to 8 m / minute with spinning ratios generally not exceeding 40. Indeed, in jacketed spinning, if one operates at high speeds and / or with high spinning ratios, the temperature of the product leaving the die is such that there is the appearance of cracks on the surface or overheating of the metal. , at least on the surface (so-called "burn" phenomenon).
• the spinning speed is generally lower than the spinning speed used when there is no quenching on the press.
• the temperature at which the metal leaves is exactly controlled and between the temperature in which the alloy is dissolved and the temperature at which cracks or burn; on the other hand, the placing in solid solution must be suitable.
• the temperature at the start of spinning is generally very close to the solid solution temperature, so that the billet does not exhibit intense precipitation which would make solid solution difficult; on the other hand, the spinning speed is slowed down, either to avoid overheating during spinning which would risk causing the appearance of cracks or burns (partial melting of metastable eutectics or not), or precisely because 'a high spinning temperature, close to the solution temperature, is less favorable at high speed than a lower temperature, due to the risk of cracks or burns.
• the outlet temperature is difficult to control because of the evolution throughout the spinning of the friction forces, and therefore of the overheating.
• a conventional lubricant for example a grease with molybdenum disulphide and / or graphite, taking certain precautions so that the lubricant remains permanently in contact with the metal.
• vitreous librifying agent whose viscosity is between 10 3 and 10 4 poises between 400 and 650 ° C. for example.
• a glassy lubricant containing elements such as P 2 O 3 ⁇ B 2 O 3 ⁇ K 2 O ⁇ Na 2 O makes it possible, under these conditions, to reach speeds greater than 100 m / minute. This process is not yet used industrially.
• the method according to the invention constitutes an improvement to these rapid spinning techniques, and makes it possible to obtain products having an excellent surface condition, and good mechanical and metallurgical characteristics under very favorable economic conditions.
• the Applicant has found that, under certain conditions, it is possible to associate, for these alloys, quenching on a press with high spinning ratios and a high spinning speed, this high spinning speed being the same, provided that 'It is sufficiently high, an element favorable to good control of the placing in solid solution before quenching.
• the spinning temperature is between 350 ° C and 480 ° C
• the outlet temperature of the die is between 480 ° C and 530 ° C, and preferably 480 ° C to 500 ° C.
• the exit temperature after spinning can be suitably controlled, since the high spinning speeds and / or the reduced friction make it possible to obtain quasi-adiabatic conditions during spinning, such so that with the exception of a small part at the end of the spun product, which can be eliminated, the temperature is uniform with a difference not exceeding 10 ° C from one end to the other of the spinning. It is also advantageous that the spinning takes place in a very short time, less than 30 seconds, and even 20 seconds, whatever the length of the billet, chosen from industrial lengths.
• the very short spinning times also allow more uniform lubrication from end to end. the other of the spinning and a better appearance. It may be advantageous not to introduce the metal into the cooling fluid immediately at the outlet of the die. Waiting before quenching, when practiced, allows perfect dissolution. Its duration, between 15 and 90 seconds, is determined by two opposing requirements: on the one hand increasing the solution time to improve the metallurgical quality of the spun product, on the other hand, not staying in the critical field of precipitation, which reduces the mechanical characteristics and sensitizes the alloy to inter-crystalline corrosion.
• a prior homogenization of the billet is generally favorable both to a good appearance and to good dissolution; this homogenization taking place between 480 ° C and 520 ° C for a period of 1 to 24 hours.
• the billet may also be advantageous to reheat the billet before spinning to a temperature close to the normal solid solution temperature of the alloy, which is often more than 20 ° C. higher than the spinning temperature.
• the billet is cooled rapidly, in less than 3 minutes, and preferably less than one minute, for example by a spraying device making it possible to avoid tapering up to the spinning temperature.
• This arrangement ensures a more complete dissolution of the alloy and makes it possible to avoid excessive precipitates during spinning. In this way, the heat released by the spinning will allow a dissolution of the metal after leaving the die in a very short time.
• Any lubricant and any lubrication technique allowing the indicated spinning rates and speeds can be used for spinning, hydrostatic spinning can also be assimilated to lubricated spinning.
• the above-mentioned glassy product (P 2 0 5 + 8 2 ° 3 + K 2 0 + Na 2 0) which is soluble in water or in a liquid containing more than 80 can be used as a lubricant. % water, the rest being quench additives; the elimination of the lubricant from the spun product is then instantaneous.
• the quenching can be carried out in a manner known per se by spraying or by immersion.
• the mechanical characteristics comply with the standards in force.
• the mechanical characteristics are slightly lower than what is obtained after dissolving in the oven, in particular at the elongations at break.
• the highest elongations are obtained when there is a waiting time of 45 seconds between spinning and quenching.
• the bar temperature is approximately 450 ° C., that is to say at the limit of the precipitation threshold. It is therefore an optimal time for the envisaged spinning case allowing a more complete solution.
• the billets cut into pieces were reheated to 490 ° C for 1/2 hour, then re. rapidly cooled to 400 ° C (1 minute) finally spun at this temperature at a speed of 70 m / min under conditions similar to those of Example 1, that is to say lubricated spinning of bars with a diameter of 22 mm.
• the outlet temperature of the bars thus obtained is between 490 and 500 ° C.
• the water quenching was then carried out immediately after spinning. Finally, the bars were stretched by 3%. They have dimensional characteristics specific to drawn bars.
• Billet in 2030 alloy 145 mm in diameter were homogenized and then cooled in ambient air without special precautions.
• the billets cut into pieces were reheated to 370 ° C., spun at this temperature with graphitized grease at a speed of 100 m / min, in the form of bars with a diameter of 12 mm.
• the exit temperature of the wire obtained is around 510 ° C. and remains constant throughout the spinning which lasts approximately 30 seconds. Water quenching was carried out 20 seconds after spinning. Finally, the bars were stretched by 3% to obtain a diameter of 11.8 mm. The dimensional tolerances are always compatible with those of the drawn products.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Organic Chemistry (AREA)
• Crystallography & Structural Chemistry (AREA)
• Materials Engineering (AREA)
• Thermal Sciences (AREA)
• Metallurgy (AREA)
• Physics & Mathematics (AREA)
• Extrusion Of Metal (AREA)
• Metal Extraction Processes (AREA)
• Forging (AREA)
• Heat Treatment Of Nonferrous Metals Or Alloys (AREA)
• Glass Compositions (AREA)
• Lubricants (AREA)
• Laminated Bodies (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=9194263

Family Applications (1)

Country Status (23)

Families Citing this family (4)

Family Cites Families (7)

• 1977
  • 1977-07-29 FR FR7724130A patent/FR2398558A1/fr active Granted
• 1978
  • 1978-06-28 DE DE7878420002T patent/DE2860131D1/de not_active Expired
  • 1978-06-28 EP EP78420002A patent/EP0000684B1/fr not_active Expired
  • 1978-07-20 OA OA56562A patent/OA06012A/xx unknown
  • 1978-07-24 ES ES471988A patent/ES471988A1/es not_active Expired
  • 1978-07-25 IT IT26049/78A patent/IT1097393B/it active
  • 1978-07-25 IL IL55216A patent/IL55216A/xx unknown
  • 1978-07-25 HU HU78CE1175A patent/HU177294B/hu unknown
  • 1978-07-25 AR AR273065A patent/AR215941A1/es active
  • 1978-07-25 MX MX174292A patent/MX150361A/es unknown
  • 1978-07-25 CH CH802578A patent/CH627382A5/fr not_active IP Right Cessation
  • 1978-07-26 DK DK333178A patent/DK333178A/da not_active Application Discontinuation
  • 1978-07-26 IE IE1513/78A patent/IE47282B1/en unknown
  • 1978-07-26 GR GR56868A patent/GR63648B/el unknown
  • 1978-07-27 AU AU38405/78A patent/AU526176B2/en not_active Expired
  • 1978-07-27 YU YU01814/78A patent/YU181478A/xx unknown
  • 1978-07-27 AT AT548278A patent/AT359360B/de not_active IP Right Cessation
  • 1978-07-27 NO NO782585A patent/NO143785C/no unknown
  • 1978-07-27 CA CA308,296A patent/CA1058109A/fr not_active Expired
  • 1978-07-27 JP JP9101278A patent/JPS5426269A/ja active Granted
  • 1978-07-28 LU LU80055A patent/LU80055A1/xx unknown
  • 1978-07-28 BE BE189568A patent/BE869353A/xx not_active IP Right Cessation
  • 1978-07-28 BR BR7804889A patent/BR7804889A/pt unknown

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