Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L9/00—Rigid pipes
  • F16L9/02—Rigid pipes of metal
• • 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
  • B22D7/02—Casting compound ingots of two or more different metals in the molten state, i.e. integrally cast
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D19/00—Casting in, on, or around objects which form part of the product
  • B22D19/16—Casting in, on, or around objects which form part of the product for making compound objects cast of two or more different metals, e.g. for making rolls for rolling mills
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D25/00—Special casting characterised by the nature of the product
  • B22D25/02—Special casting characterised by the nature of the product by its peculiarity of shape; of works of art
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D31/00—Cutting-off surplus material, e.g. gates; Cleaning and working on castings
  • B22D31/002—Cleaning, working on castings
• • 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
  • B22D7/06—Ingot moulds or their manufacture
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/4998—Combined manufacture including applying or shaping of fluent material
  • Y10T29/49988—Metal casting
  • Y10T29/49989—Followed by cutting or removing material

Definitions

• the invention relates to the field of metallurgy, and more particularly to the manufacture of bimaterial shells, that is to say of parts formed of two concentric solid parts of annular shapes made of two different materials and secured to each other. the other.
• ferrules as constituents of reactor vessels or pressurizers.
• These ferrules may be manufactured by welding two ferrules initially separated and each manufactured by any method, or a ferrule and a band to be disposed on a surface of the ferrule.
• the outer shell may, for example, be low-carbon steel type 16MND5 and the inner ferrule be 304L type austenitic stainless steel initially in strip form.
• the outer shell of carbon steel may be obtained by forging, and the inner ferrule of stainless steel may, as has been said, be constituted by a band that is welded to the inner surface of the outer shell.
• the inner diameter of the inner shell may be between 2 and 9 meters, its height may be between 2 and 5 meters, the thickness of the ferrules may be of the order of 50mm to 600mm for the outer shell and from 5mm to 100mm for the inner shell.
• the object of the invention is to provide a method of manufacturing such bimaterial ferrules having a better productivity and an excellent reliability.
• the subject of the invention is a process for manufacturing a bimaterial shell consisting of an annular outer shell and an annular inner shell welded to each other, the two rings being in different materials, characterized in that:
• - Source casting and solidification of the outer shell is carried out in a casting space defined by a casting base, a wall of a first mold arranged on the casting base and an outer wall, movable upwards, a second mold, disposed on said base and concentric with the first mold; said movable outer wall of the second mold is lifted so as to reveal the skin of the outer shell which has solidified against it;
• the outer wall of the second mold can be lifted when solidification of the outer shell is completed.
• the interface between the outer shell and the outer wall of the second mold can be lubricated.
• the outer shell may be carbon steel and the inner shell of stainless steel.
• the invention also relates to a device for the manufacture of a bimaterial shell consisting of an annular outer shell and an annular inner shell welded to each other, the two rings being of different materials characterized in that it comprises:
• It may comprise a chuck internally cooled and surrounded by the inner wall of the second mold.
• Said molds may comprise flyweights.
• the outer wall of the second mold may include means for lubricating its interface with the metal intended to form the outer shell.
• the subject of the invention is also a bi-material shell consisting of an annular outer shell and an annular inner shell welded to each other, the two rings being of different materials, characterized in that was obtained by the above method.
• the outer ferrule may be 16MND5 carbon steel and the inner ferrule may be 304L stainless steel.
• the ferrule may be a constituent of a nuclear or petrochemical reactor vessel
• the ferrule may be a component of a nuclear reactor pressurizer.
• the invention aims to achieve successively, or almost simultaneously, the solidification of two hollow ingot whose shapes and compositions correspond to those of the two components of the bi-material shell that is desired to obtain. .
• the solidification of the outer face of the ingot constituting the inner ferrule takes place directly on the inner face of the ingot constituting the outer ferrule, or vice versa, and their joining is carried out by welding-diffusion or co-solidification of the metals constituting them.
• FIG. 1 represents an exemplary device according to the invention used for the manufacture of bi-material ferrule. It has as essential elements in the first place a base 1 for the casting source of a slightly conical annular shaped ingot in the example shown.
• This base 1 in the example shown, comprises in its central part a base 2 of substantially cylindrical shape and protruding from the remainder of the base 1.
• a first mold is defined in part by a cylindrical metal wall 3 deposited on the base 1, and whose lower part encloses the base 2, the upper face constitutes the bottom of the first mold.
• This wall 3 of the first mold may optionally be cooled externally or internally by circulation of a fluid, or be uncooled.
• the inner face of the first mold 3 serves to ensure the solidification of the outer portion of the ferrule.
• the 1 comprises an inlet channel 4 for liquid metal (for example a low-carbon steel 16MND5), connected to a mother of casting not shown, that is to say to a vertical pipe for receiving the liquid metal s escaping from the bottom of the ladle where its temperature and composition have been regulated.
• the input channel 4 is divided into a plurality of output channels (of which two 5, 6 are visible in the figures) which open on the upper face of the base 2 and make it possible to send liquid metal to various parts of the annular casting space 7 delimited externally by the wall 3 of the first mold.
• a second mold is defined by the upper face of the base 2 of the base 1, two other cylindrical metal walls 8, 9 concentric, defining between them an annular space 10 for casting the inner part of the ferrule.
• the base 1 comprises another inlet channel 1 1 for liquid metal (for example a 304L austenitic stainless steel), connected to another casting mother (not shown) that the casting mother feeding the channel entry 4 previously cited.
• This other input channel 1 1 is preferably divided into a plurality of output channels (two of which 12, 13, located at the rear of the sectional plane of the figures, just like the input channel 1 1) are represented. in dotted lines in the figures. They open on the upper surface of the base
• This second mold has, according to the invention, a feature which is that its outermost wall 8 which separates the two casting spaces 7, 10 (and therefore constitutes an inner wall for the first mold) is vertically movable to the control, in ways that will be seen later. Unrepresented lifting means, controlled by an operator or an automated device, provide this mobility.
• the innermost wall 9 of the second mold is indifferently fixed or removable. The installation is completed by a cooling system of the innermost wall 9 defining the second mold.
• this cooling system may be a mandrel 14 cooled internally by circulation of a fluid (for example water) as described in documents FR-A-2,525,131, FR-A-2,543,031, FR-A- 2 676 670 or FR-A-2 676 671
• a fluid for example water
• the installation is also preferably provided, in the upper parts of the casting spaces 7, 10, weights 15, 16, that is to say, circumferential pieces of refractory material disposed on the fixed walls of the molds:
• Figure 2 shows the installation during casting and solidification of the outer shell 17 made of carbon steel.
• a carbon steel in the liquid state has been introduced into the device through the inlet channel 4 and has entered the casting space 7 defined by the inner wall of the first mold 3 and the wall outer 8 of the second mold.
• FIG 2 the shell 17 is being solidified and a solidified skin 18 is formed against the walls of the first mold.
• Figure 3 shows the installation during casting and solidification of the inner ring of stainless steel. After having lifted the cylindrical wall 8 which separated the two casting spaces 7, 10 so as to reveal the solidified skin of the outer shell 7, a stainless steel was introduced through the inlet channel 11. liquid state. It has penetrated into the casting space defined by the outer shell 17 and the other wall defining the casting space of the second shell. This solidifies against the wall 9 cooled by the mandrel 14, and also against the inner surface of the outer shell 17.
• the temperatures of the two metals are chosen at the time of casting of the inner ferrule so that the chemometallurgical diffusion between the carbon steel and the stainless steel is carried out at their interface significantly, or that a co-solidification takes place at this interface. In this way, an excellent quality of the joining of the two ferrules is obtained by a welding-diffusion or co-solidification phenomenon.
• the first ingot mold 3 and the wall 9 of the second mold are removed, and the blank of the desired bi-material shell is obtained, ready to be forged and / or machined for obtaining the final shell, after also possible heat treatments.
• the invention makes it possible to eliminate the welding phase of the stainless steel strip and to verify the welds, and thus to gain at least 5 to 10% of the overall manufacturing time of a two-component shell of large size. For example, in a non-limiting way, this may represent 5 to 10 weeks on a manufacturing plan that may be spread over a hundred weeks
• the mold for making such a shell is predominantly cast iron, the removable internal device being made of cast iron or steel.
• a circular forging and / or rolling step allows the production of a blank having substantially the final length of the two-component shell, and a minimum blank thickness adapted to the subsequent machining phase.
• Finally a machining phase is performed to bring the bimetallic ferrule from the blank state to the finished part state with predefined dimensions.
• the rings 17, 18 annular may be cylindrical, frustoconical, rectangular section or other.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Continuous Casting (AREA)
• Forging (AREA)
• Adornments (AREA)
• Pressure Welding/Diffusion-Bonding (AREA)

Applications Claiming Priority (2)

Publications (1)

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Citations (1)

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• 2010
  • 2010-04-02 FR FR1052508A patent/FR2958194B1/fr not_active Expired - Fee Related
• 2011
  • 2011-01-04 UA UAA201212460A patent/UA107965C2/ru unknown
  • 2011-04-01 US US13/638,783 patent/US8978714B2/en not_active Expired - Fee Related
  • 2011-04-01 WO PCT/FR2011/050736 patent/WO2011121251A1/fr active Application Filing
  • 2011-04-01 CN CN201180027210.4A patent/CN103025455B/zh not_active Expired - Fee Related
  • 2011-04-01 RU RU2012146729/02A patent/RU2557040C2/ru not_active IP Right Cessation
  • 2011-04-01 EP EP11719324A patent/EP2552625A1/fr not_active Withdrawn
  • 2011-04-01 JP JP2013501918A patent/JP5662556B2/ja not_active Expired - Fee Related
  • 2011-04-01 KR KR1020127028259A patent/KR101809560B1/ko active IP Right Grant
  • 2011-04-01 BR BR112012025065A patent/BR112012025065B8/pt not_active IP Right Cessation

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