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
  • B21C1/00—Manufacture of metal sheets, metal wire, metal rods, metal tubes by drawing
  • B21C1/003—Drawing materials of special alloys so far as the composition of the alloy requires or permits special drawing methods or sequences
• • 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
  • B21C23/02—Making uncoated products
  • B21C23/04—Making uncoated products by direct extrusion
  • B21C23/08—Making wire, bars, tubes
• • 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
  • B21C23/01—Extruding metal; Impact extrusion starting from material of particular form or shape, e.g. mechanically pre-treated
• • 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
  • B21C43/00—Devices for cleaning metal products combined with or specially adapted for use with machines or apparatus provided for in this subclass
  • B21C43/02—Devices for cleaning metal products combined with or specially adapted for use with machines or apparatus provided for in this subclass combined with or specially adapted for use in connection with drawing or winding machines or apparatus
  • B21C43/04—Devices for de-scaling wire or like flexible work
• • 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
  • B21C9/00—Cooling, heating or lubricating drawing material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
  • B21J1/00—Preparing metal stock or similar ancillary operations prior, during or post forging, e.g. heating or cooling
  • B21J1/04—Shaping in the rough solely by forging or pressing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D21/00—Casting non-ferrous metals or metallic compounds so far as their metallurgical properties are of importance for the casting procedure; Selection of compositions therefor
  • B22D21/002—Castings of light metals
  • B22D21/005—Castings of light metals with high melting point, e.g. Be 1280 degrees C, Ti 1725 degrees C
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D7/00—Casting ingots, e.g. from ferrous metals

Definitions

• the invention relates to a method for manufacturing elongated products of titanium material, or titanium alloy, or blanks of such products.
• elongate product here refers to a metal part that has substantially smaller or even much smaller cross-sectional dimensions than its length.
• Elongated products include metal parts, the production of which usually comprises at least one spinning operation.
• the elongated product qualification is however not reserved for such parts.
• the elongated products more particularly comprise the metal parts resulting from a spinning operation, and comprise the profiled parts, including the hollow profiles and the tubes.
• a "blank" of an elongate product is an elongated piece that can undergo different shaping, machining or surface treatments to give rise to a finished product.
• the areas of use of elongated products made of titanium or titanium alloy are numerous. They include in particular aeronautical and aerospace construction.
• titanium material which mass may comprise titanium sponges, titanium chips, titanium scrap (sometimes referred to as "titanium scrap" by abuse of language). and / or more generally recycled titanium material.
• This mass of titanium material is then melted and cast into a single ingot, which has a large diameter.
• Electron bombardment fusion also referred to as “Electron beam furnace” is suitable for melting a mixture of titanium sponge and recycled material (scrap) as a raw material. Recycled materials being less expensive than titanium sponges, it is understandable economic interest that can take such a process.
• Plasma torch fusion and cold crucible electron bombardment are newer techniques that provide more continuous casting and the ability to melt a larger proportion of titanium scrap. These techniques are thus more economical than conventional electron bombardment fusion.
• This reflow / casting is conventionally performed by the technique of remelting by vacuum arc, also called “VAR" (English “vacuum arc remelting”).
• VAR vacuum arc remelting
• the ingot obtained after the first melting constitutes an electrode which will gradually be melted, and simultaneously cast into an ingot of adjacent diameter, continuously.
• the diameter of the new ingot is about 10 to 20% greater than the diameter of the consumable electrode, that is to say of the first ingot.
• a vacuum arc fusion technique has more recently been developed. and in autocreuset mode, also referred to as "skull melting” (literally “carapace fusion” in French).
• autocreative mode is meant a melting process in which the furnace crucible is cooled so that a melt shell is formed over it, here titanium, or additional crucible, isolating the remainder of the melt from the furnace. oven crucible.
• Part of the mass of titanium to be melted is placed in a crucible, while the other part of this mass takes the form of a consumable electrode.
• the whole of the titanium mass will be melted thanks to an electric arc generated between the electrode and the crucible then put to the bath temperature.
• the melt is then poured into one or more ingot molds, at a time, by inclination of the crucible.
• the "skull melting” allows rapid casting, in one go, batch (inclination), of the entire mass of melt. This can make it possible to avoid casting defects related to the slowness and progressivity of the older fusion techniques.
• the "skull melting” allows the fusion of sponges of titanium as well as recycled materials, indifferently.
• a further advantage is that the metal matrix that forms in contact with the crucible can be easily, or even directly, reused as a new electrode.
• the capacity of the current presses does not make it possible to spin directly the ingots obtained after reflow "VAR” or fusion "skull melting", because of too large diameter of the ingot.
• One or more forging diameter reduction operations are required to convert the large diameter ingot into one or more billets of a diameter suitable for the spinning press and the desired elongated product.
• an ingot from a "VAR” remelting, or a “skull melting” may have a diameter of about 600 millimeters and be converted by successive forging operations into billets of about 120 millimeters diameter, or a diameter reduction by forging of the order of 25 (2500%).
• a typical manufacturing range of elongated high quality titanium or titanium alloy products from a titanium mass comprises the following operations: - melting of this mass of titanium, or alloy of titanium, titanium, and casting of a single ingot, of large diameter;
• One or more surface treatment operations and / or altering the overall appearance of the elongated product can then be implemented to obtain the finished elongated product.
• the Claimants have sought to improve the situation.
• the proposed method is directed to a method of manufacturing elongated products of titanium or titanium alloy, or blanks of such products, comprising the preparation of a mass of titanium material or titanium alloy, the melting of this mass. by electric arc and autocreuset mode, the casting of one or more ingots of substantially cylindrical shape and diameter less than about 300 mm from the melt, and then spinning one or more of these ingots at a temperature of between 800 0 C and 1200 0 C by means of a spinning press.
• Such a method makes it possible to obtain healthy elongate products, that is to say substantially devoid of any casting defect, and of a mechanical strength, in particular as measured by tensile tests, at least equal to the products. obtained by conventional or currently known methods.
• this method makes it possible to obtain elongated products of comparable quality to the products in accordance with the aeronautical standards currently in force, at least with regard to strength properties, for example the United States of America AMS 4935 or AMS 4945.
• This process also offers a manufacturing cost of the product potentially lower than the manufacturing cost of conventional or currently known processes, as well as a shortened manufacturing time, partly related to the absence of any forging operation, and more generally to significant reduction of the diameter of ingots cast prior to the spinning operation and the simultaneous casting of several ingots.
• the proposed method improves the availability of elongated products obtained, in particular due to a simplification of the manufacturing range and the possibility of using in the mass of titanium or prepared titanium alloy a large proportion of recycled material.
• FIG. 1 is a diagram of steps illustrating the method according to the invention
• FIG. 2 is a diagram of steps illustrating a variant of the method of FIG.
• FIG. 3 is a diagram of steps illustrating a complementary method that can be implemented in addition to the methods of FIGS. 1 and 2.
• the attached drawings may not only serve to complete the invention, but also contribute to its definition, if any.
• Figure 1 illustrates a method of manufacturing elongated products of titanium, or titanium alloy, or blanks of products of this type.
• the process of FIG. 1 comprises an operation for preparing a mass of titanium material or a titanium alloy, an operation of melting this mass by an electric arc and in a self-heating mode, a casting operation of a or more ingots of substantially cylindrical shape and of diameter less than about 300 mm from the melt, then a spinning operation 40 of one or more of these ingots at a temperature between
• the elongated products resulting from this spinning step may undergo one or more finishing or semi-finishing steps 50.
• the process of Figure 1 begins with an operation for preparing a mass of titanium or titanium alloy 10.
• the chemical composition of this mass is in accordance with the desired shade for the elongate product.
• the chemical composition of this mass may be intended to obtain a TA6V4 alloy, or equivalent, as mentioned in the United States of America AMS 4935, or TA3V2.5, or equivalent, as mentioned in US Pat. the United States of America standard AMS 4945.
• alloys are particularly used in the aeronautical field, for which strict standards require a high metallurgical quality of the products. Their use is not limited to this sector of activity. And the implementation of the method of FIG. 1 is not limited either. to these particular alloys, but on the contrary extends to many different titanium compositions, depending in particular the intended application, for example T40, T60 or others.
• This mass may include titanium sponge, titanium falls or titanium alloy, called w scrap "in English, titanium shavings or titanium alloy, of all or part of a shell or pocket or gangue, resulting from a fusion "skull melting", or more generally titanium material recycled in any form.
• the composition of the recycled material is controlled with respect to its quality and its chemical composition.
• the recycled elements can come from milling, processed recycled materials intended for the titanium industry for remelting, machining residues of titanium or titanium alloy parts, or other.
• recycled materials may have many different chemical compositions, for example according to the desired shade for the elongated product, but not necessarily. These materials may correspond to the alloys mentioned above.
• the recycled elements have an availability and a mass cost, that is to say a cost per kilogram of material, less than titanium sponges, so that it is advantageous to favor the use.
• the mass of titanium or titanium alloy of the preparation step 10 may also comprise shading and / or alloying elements in proportions which depend on the continuation of the process, the intended application, and / or the desired shade for the elongate product.
• the process of FIG. 1 is continued by an electric arc melting and autocreative operation of the mass of titanium material or titanium alloy prepared in step 10.
• this fusion is done in the form of a fusion "skull melting".
• a “skull melting” melting is carried out by means of an oven comprising a vacuum box and an appropriately shaped crucible housed inside the box.
• a consumable electrode is mounted inside the box while titanium material is loaded into the crucible.
• a large potential difference is generated between the electrode and the crucible.
• this potential difference reaches a certain threshold, a high energy level electric arc is created between the low end of the electrode and the titanium material located in the crucible.
• the electrode can be mounted on a vertical piece that moves up and down in the box.
• the molten titanium mass present in the crucible can be cast, in one go, in one or more molds of selected shape, here of circular section and diameter less than 300 mm, placed at the inside the box. This casting is therefore very fast: it can for example be performed by tilting the crucible.
• the "skull melting" is thus a technique of fusion / batch casting.
• this gangue forms an additional crucible arranged in the crucible materially provided in the furnace (melting autocreuset). After cooling, this gangue can be used as a consumable electrode for a new melting, which is interesting in terms of costs.
• the furnace crucible may be shaped so that the gangue has a shape adapted to its subsequent consumable electrode function.
• the mass of titanium prepared in step 10 advantageously comprises the gangue, or shell, resulting from the melting and casting by "skull melting" of a previous titanium mass.
• the titanium mass prepared in step 10 comprises a large proportion of recycled titanium material.
• the titanium mass of the operation 10 comprises exclusively one or more skull shells, recycled material and the necessary alloying or shading elements, in appropriate proportion.
• the process for preparing the mass of titanium or titanium alloy 10 mainly consists in producing a mixture of titanium or titanium alloy materials, most or all of which is in the mass, consists of recycled materials. Only the addition of shading elements may still be necessary.
• the process of FIG. 1 therefore has a particular advantage in that it makes it possible to obtain high quality products at a lower cost than conventional processes, because of the almost exclusive use of recycled materials permitted by the use of electric arc melting and autocreative mode.
• the temperature used for this melting operation may depend on the composition of the mass of the preparation operation 10.
• a supercooling temperature greater than 1600 ° C. makes it possible to melt this mass in most of the possible compositions. .
• FIG. 1 The process of FIG. 1 is continued by an ingot molding operation of generally circular section, the diameter of which is less than about 300 mm. Preferably the diameter of these ingots is less than 250 mm.
• This casting concerns the entire melt, all at once (in a "batch") and rapidly, for example by inclining the crucible containing the molten titanium mass
• ingots are cast whose length is related to the length of the ingots to be spun in operation 40.
• the length of an ingot cast in operation 30 may be chosen so as to be equal to a multiple of the length of a spinning ingot to the operation 40, to avoid material losses. More generally, the length of the ingot cast in the operation 30 may also be chosen to be equal to the sum of the lengths of ingot to be spun the spinning operation 40.
• the mass of titanium, or titanium alloy, cast in operation 20 and therefore the mass of titanium, or of titanium alloy, prepared for the operation 10 can be chosen, in quantity, as a function of number of ingots that one wishes to spin, and thus previously flow, and their size.
• the diameter of each of the ingots cast in the operation 30 is less than 300 mm.
• Each of these ingots can then be spun in operation 40, without significant reduction of its diameter prior to this spinning operation.
• a crushing operation can nevertheless take place between the casting of the operation 30 and the spinning of the operation 40. Although a decrease in diameter inevitably results from a crushing operation, this reduction is so small (the order of a few tenths of a millimeter) that can not be considered as a significant reduction in the diameter of the ingot.
• the purpose of peeling is to remove the superficial layer of cast ingots, and as such can not be described as a diameter reduction operation, the object of which is by definition to reduce the diameter of the ingot in such a way that significant.
• the cylindrical ingots cast in the operation 30 may have dimensions similar to each other, as regards their diameter and their length.
• These ingots may also have different lengths and / or diameters, for example for the production of different elongate products.
• the diameter and the length of each of the ingots cast in the operation 30 may be chosen depending on the diameter and the length of the ingot (s) during operation 40. It is known to determine the length and the diameter of a spinning ingot according to the elongated product which it is desired to obtain at As a result of the spinning operation 40. In other words, the method of FIG. 1 makes it possible to obtain, after the casting operation 30, an ingot the dimensions of which are adapted to the spinning and whose dimensions can be calculated. depending on the dimensions of the desired elongate product.
• the method of Figure 1 differs from conventional methods, which provide for the casting of a single ingot, in particular to reduce the mass cost of the cast ingot, and forging operations to reduce the diameter of the ingot.
• the diameter of the cast ingot is imposed in conventional methods (of the order of 400 to 600 mm), while this diameter can be chosen here.
• the presses currently in use do not allow the spinning of ingots longer than 1500 millimeters.
• the ingots cast in step 30 have a length less than 1500 millimeters, but could be longer in the case where more powerful presses came to light.
• the process of FIG. 1 is completed by a hot spinning operation 40 of these cylindrical ingots on a spinning press to obtain an elongated product or a blank of such a product.
• the spinning operation 40 may be adapted to obtain a solid product or a hollow product.
• the spinning temperature is greater than the so-called "transus ⁇ " temperature, which depends on the composition of the ingot.
• the spinning operation 40 is carried out hot, at a temperature generally between 800 0 C and 1200 0 C.
• the spinning is performed at a temperature above 900 0 C to ensure good plasticity of the material and lower at 1150 ° C to avoid unnecessary energy expenditure while obtaining a suitable metallographic structure.
• the spinning is carried out by means of a conventional spinning press equipped with a die and a punch.
• a rod also called “needle” (and in this case, the ingot has to have been previously drilled).
• This spinning is carried out hot, in the presence of a lubricating agent.
• This lubricating agent generally comprises glass, that is to say the usual lubricating agent for conventional hot-spinning operations at a temperature above 900 ° C.
• the process of FIG. 1 does not require any operation to reduce the diameter of the ingot cast during the operation 30 prior to the spinning operation 40.
• the metallurgical quality of the elongated product resulting from the spinning operation 40 is surprisingly comparable to the metallurgical quality of the products made according to the conventional methods, at least as regards the mechanical strength, in particular as measured by cold tensile test.
• the set of ingots cast in operation 30, or only a few of them, can be spun in parallel on several different presses, possibly after cutting, which significantly increases the productivity of the process.
• the cost of the elongated product obtained is reduced by the same amount.
• the ingot cast in operation 30 is not remelted in the process of FIG. 1.
• the quality of the elongated product obtained after the spinning operation 40 is surprisingly, quite sufficient, with regard to the absence of casting defects and mechanical strength, compared to the products obtained after reflow "VAR", and without any forging operation, which forging is known to improve this quality .
• FIG. 2 illustrates an alternative embodiment of the method of FIG. 1.
• the spinning operation of the ingots 30 here comprises a casting operation of first ingots with a diameter less than 300 millimeters 300, then a "VAR reflow" operation 302 of these first ingots.
• each of the first ingots obtained after melting / casting "skull melting", or at least some of them, are individually subject to a "VAR" melting.
• These first ingots serve as consumable electrodes for this fusion.
• the casting operation of ingots 30 finally comprises a casting operation of ingots to be spun from this second mass of melt, that is to say ingots of cylindrical shape and diameter less than 300 mm.
• the casting is done gradually, as the consumable electrode melts.
• the diameter of the ingot obtained, or second ingot is generally larger, of the order of 10 to 20% than the diameter of the electrode. Consequently, the diameter of the ingots cast in the operation 300 must take this increase into account, in particular so that the ingots to be spun in the operation 40 have a diameter of less than 300 mm without requiring any operation of diameter reduction.
• FIG. 3 illustrates a finishing process 50, or semifinished, which can be carried out on elongate products made according to one of the methods of FIGS. 1 and 2.
• An elongated product resulting from the spinning operation 40 may undergo one or more of the following operations:
• a straightening and straightening operation 52 intended to straighten the elongate product, with regard to its cross-section and general appearance
• a sand blasting operation 55 also known as sanding
• a shaping operation 56 a control operation 57 by one or more of the known non-destructive inspection techniques, such as ultrasound, radiography, eddy currents, or other,
• the proposed method makes it possible to obtain elongated products of satisfactory quality, in accordance with the standards in force, without any forging operation, making the conventional "VAR" remelting operation optional and allowing a significant use of recycled material.
• the proposed method is devoid of any forging operation.
• the Applicants have indeed realized, against all odds and contrary to ideas widely known in the art, that mechanical properties of comparable elongated products, or at the very least sufficient, can be obtained by spinning alone, making superfluous the beneficial action of a forging operation.
• the proposed process has a lower manufacturing cost, shortened manufacturing times and increased product availability.
• the melting and casting operation 30 has been described as implementing a "skull melting” fusion.
• This fusion technique allows batch fusion / casting as opposed to progressive fusion / casting processes.
• Today, only this technique allows such a casting mode.
• the processes of Figures 1 and 2 could be implemented with a different melting technique provided that it has characteristics similar to the "skull melting", that is to say, to produce ingots capable of spinning, diameter less than 300 mm for a reasonable cost, preferably with use of a large amount of recycled material and with batch casting.
• the reflow of the steps 302 and 304 could be carried out with different melting processes provided that they improve the metallographic quality of the ingots obtained and allow, for an acceptable cost, to obtain ingots of size adapted to the operation.
• spinning 40 that is to say of diameter less than 300 mm.
• the elongated product obtained can undergo one or more forming operation, in particular forging, including to further reduce its section.
• the elongated products obtained can be the subject of subsequent shaping, for example by bending.
• the invention has been described with reference to the aeronautical field, in particular with regard to the standards in force in this field. This is due to the fact that this sector represents a large sector of application of elongated titanium products and that it requires a high quality of these products. This in no way limits the application of the method described to this particular line of business. Moreover, other sectors using titanium, or titanium alloy products, and demanding high quality products can refer to the standards established by the aerospace sector, without being part of this sector. The invention therefore also applies to these sectors. More generally, the invention is intended to be applicable in all areas requiring elongated titanium products for non-aeronautical and high quality applications, in addition to the aeronautical sector.
• the method according to the invention offers such flexibility and such cost reduction that it can offer new applications of elongated titanium products in non-aeronautical and / or general public areas.
• elongate products made by the process of Figure 1 do not comply with the United States of America standard AMS 4935, for use in aircraft construction, in that they have not suffered several mergers, including one under vacuum. They nevertheless constitute products of comparable quality, in particular in terms of mechanical strength.
• the Applicant believes that these products could be used instead of the products defined in this standard or that this standard should evolve to include the products obtained by the process of Figure 1.
• the quality of these products is such that many sectors that refer to said standard without being constrained can advantageously use them.
• the invention encompasses all the variants that can be envisaged by those skilled in the art, in the light of the present description.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Extrusion Of Metal (AREA)
• Continuous Casting (AREA)
• Crucibles And Fluidized-Bed Furnaces (AREA)
• Furnace Details (AREA)
• Forging (AREA)

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• 2009
  • 2009-04-30 FR FR0902114A patent/FR2944983B1/fr not_active Expired - Fee Related
• 2010
  • 2010-04-23 CN CN201080019124.4A patent/CN102438764B/zh active Active
  • 2010-04-23 UA UAA201113982A patent/UA104024C2/ru unknown
  • 2010-04-23 JP JP2012507794A patent/JP2012525497A/ja active Pending
  • 2010-04-23 RU RU2011148086/02A patent/RU2541251C2/ru active
  • 2010-04-23 KR KR1020117028572A patent/KR20120037378A/ko not_active Application Discontinuation
  • 2010-04-23 EP EP10718244.6A patent/EP2424688B1/fr active Active
  • 2010-04-23 WO PCT/FR2010/000329 patent/WO2010125253A1/fr active Application Filing

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