WO2011151334A1 - Legierung, schutzschicht und bauteil - Google Patents
Legierung, schutzschicht und bauteil Download PDFInfo
- Publication number
- WO2011151334A1 WO2011151334A1 PCT/EP2011/058965 EP2011058965W WO2011151334A1 WO 2011151334 A1 WO2011151334 A1 WO 2011151334A1 EP 2011058965 W EP2011058965 W EP 2011058965W WO 2011151334 A1 WO2011151334 A1 WO 2011151334A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- nickel
- alloy according
- silicon
- protective layer
- weight
- Prior art date
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/03—Alloys based on nickel or cobalt based on nickel
- C22C19/05—Alloys based on nickel or cobalt based on nickel with chromium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C30/00—Alloys containing less than 50% by weight of each constituent
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
- C23C28/32—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer
- C23C28/321—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer with at least one metal alloy layer
- C23C28/3215—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer with at least one metal alloy layer at least one MCrAlX layer
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
- C23C28/34—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates
- C23C28/345—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
- C23C28/34—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates
- C23C28/345—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer
- C23C28/3455—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer with a refractory ceramic layer, e.g. refractory metal oxide, ZrO2, rare earth oxides or a thermal barrier system comprising at least one refractory oxide layer
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C30/00—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
- C23C4/06—Metallic material
- C23C4/073—Metallic material containing MCrAl or MCrAlY alloys, where M is nickel, cobalt or iron, with or without non-metal elements
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
- C23C4/06—Metallic material
- C23C4/08—Metallic material containing only metal elements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D25/00—Component parts, details, or accessories, not provided for in, or of interest apart from, other groups
- F01D25/005—Selecting particular materials
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
- F01D5/12—Blades
- F01D5/28—Selecting particular materials; Particular measures relating thereto; Measures against erosion or corrosion
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
- F01D5/12—Blades
- F01D5/28—Selecting particular materials; Particular measures relating thereto; Measures against erosion or corrosion
- F01D5/288—Protective coatings for blades
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
- F05C2201/00—Metals
- F05C2201/04—Heavy metals
- F05C2201/0433—Iron group; Ferrous alloys, e.g. steel
- F05C2201/0463—Cobalt
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
- F05C2201/00—Metals
- F05C2201/04—Heavy metals
- F05C2201/0433—Iron group; Ferrous alloys, e.g. steel
- F05C2201/0466—Nickel
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2260/00—Function
- F05D2260/95—Preventing corrosion
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2300/00—Materials; Properties thereof
- F05D2300/10—Metals, alloys or intermetallic compounds
- F05D2300/12—Light metals
- F05D2300/121—Aluminium
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2300/00—Materials; Properties thereof
- F05D2300/10—Metals, alloys or intermetallic compounds
- F05D2300/13—Refractory metals, i.e. Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W
- F05D2300/132—Chromium
-
- 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T50/00—Aeronautics or air transport
- Y02T50/60—Efficient propulsion technologies, e.g. for aircraft
-
- 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
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
Definitions
- the invention relates to an alloy according to claim 1, a protective layer for protecting a component against corrosion and / or oxidation, in particular at high temperatures, according to claim 13 and a component according to claim 15.
- Protective layers for metallic components which are intended to increase their corrosion resistance and / or oxidation resistance are known in large numbers in the prior art. Most of these protective layers are known under the collective name MCrAlY, where M represents at least one of the elements selected from the group consisting of iron, cobalt and nickel and further essential components are chromium, aluminum and yttrium.
- WO 91/01433 AI Examples of the construction of a turbine blade with a monocrystalline substrate, which in turn can be complex, are shown in WO 91/01433 AI. While the physical capacity of the now escape ⁇ oped basic materials for highly stressed components with a view to possible further increases in the inlet temperatures is largely unproblematic to resort to protective layers to achieve sufficient resistance to oxidation and corrosion. In addition to the sufficient chemical resistance of a protective layer under the attacks that are expected of flue gases at temperatures in the order of 1000 ° C, a protective layer must also have sufficient mechanical properties, not least in view of the mechanical interaction between the protective layer and the base material , to have.
- the protective layer must be sufficiently ductile in order to be able to follow any deformations of the base material and not to break, since this would create points of attack for oxidation and corrosion.
- the typical problem arises that an increase in the An ⁇ parts of elements such as aluminum and chromium, which can improve the resistance of a protective layer against oxidation and corrosion, leads to a deterioration of the ductility of the protective layer, so that with a mechanical Ver ⁇ say , in particular the formation of cracks, is to be expected in a mechanical stress usually occurring in a gas turbine.
- an object of the present invention to provide an alloy and a protective layer which has good high-temperature resistance in corrosion and oxidation, has good long-term stability and, in addition, a mechanical stress to be expected particularly in a gas turbine at a high temperature well adjusted.
- Another object of the invention is to provide a component which has increased protection against corrosion and oxidation.
- a component according to claim ⁇ 15 in particular a component of a gas turbine or steam turbine, which has a protective layer of theThatthane nen type to protect against corrosion and oxidation at high temperatures.
- FIG. 1 shows a layer system with a protective layer
- FIG. 2 shows compositions of superalloys
- FIG. 3 shows a gas turbine
- Figure 4 shows a turbine blade
- Figure 5 is a combustion chamber.
- a protective layer 7 for protecting a component against corrosion and oxidation at a high temperature consists essentially of the following elements (indication of the parts in% by weight):
- Nickel preferably forms the matrix.
- the list of Ni, Co, Cr, Al, Y, Si, Ta is final.
- the proportions of the individual elements are particularly tuned with regard to their effects, which are to be seen in particular in connection with the element silicon. When the proportions are such that no silicon precipitates are formed, are formed advantageously no brittle phases during use of the protective layer ⁇ so that the runtime behavior is improved and Longer side ⁇ device.
- the protective layer with good corrosion resistance, has a particularly good resistance to oxidation and is also distinguished by particularly good ductility properties, so that it is particularly qualified for use in a gas turbine 100 (FIG. 3) with a further increase in the inlet temperature.
- a gas turbine 100 FIG. 3
- Chromium-silicon precipitates, which become brittle in the course of use.
- the powders are applied, for example, by plasma spraying (APS, LPPS, VPS, ...) to form a protective layer.
- plasma spraying APS, LPPS, VPS,
- Other methods are also conceivable (PVD, CVD, SPPS, ).
- the protective layer 7 described also acts as Haftvermitt ⁇ Lersch layer to a superalloy.
- this protective layer 7 other layers insbeson ⁇ particular ceramic thermal barrier coatings 10 may be applied.
- the protective layer 7 is advantageous ⁇ as applied to a substrate 4 made of a superalloy tion on nickel or cobalt base ( Figure 2).
- compositions of this type are be ⁇ known as casting alloys under the names GTD222, IN939, IN6203 and Udimet 500th
- FIG. 2 Further alternatives for the substrate 4 (FIG. 2) of the component 1, 120, 130, 155 are listed in FIG.
- the thickness of the protective layer 7 on the component 1 is the thickness of the protective layer 7 on the component 1
- the protective layer 7 is particularly suitable for protecting the component 1, 120, 130, 155 against corrosion and oxidation, while the component at a material temperature of about 950 ° C, in aircraft turbines also about 1100 ° C, with a
- the protective layer 7 according to the invention is thus particularly qualified for protecting a component of a gas turbine 100, in particular a guide blade 120, blade 130 or a heat shield element 155, which is acted upon with hot gas before or in the turbine of the gas turbine 100 or the steam turbine ⁇ .
- the protective layer 7 can be used as an overlay (protective layer is the outermost layer or as a bondcoat (protective layer is an intermediate layer).
- FIG. 1 shows a layer system 1 as a component.
- the layer system 1 has a substrate 4.
- the substrate 4 may be metallic and / or ceramic. Particularly in turbine components, such as turbine runners 120 (FIG. 4) or vanes 130 (FIGS. 3, 4), heat shield elements 155 (FIG. 5), as well as other housing parts of a steam or gas turbine 100 (FIG. 3), the substrate 4 a nickel-, cobalt- or iron-based superalloy, in particular ⁇ it consists of it.
- nickel-based superalloys ( Figure 2) are used.
- the protective layer 7 according to the invention is present.
- this protective layer 7 is applied by plasma spraying (VPS, LPPS, APS,).
- the layer system consists of substrate 4,
- Protective layer 7 and ceramic thermal barrier coating 10, optionally a TGO under the thermal barrier coating 10th The protective layer 7 can be applied to newly manufactured components and remanufactured components from the refurbishment ⁇ be introduced.
- Reprocessing means that components 1 are separated after their use, if appropriate, of layers (heat insulating layer) and corrosion and oxidation products are removed, for example by a sheurebehand ⁇ averaging (acid stripping). If necessary, cracks still have to be repaired. Thereafter, such a component can be coated again, since the substrate 4 is very expensive.
- FIG. 3 shows by way of example a gas turbine 100 in a longitudinal partial section.
- the gas turbine 100 has a rotatably mounted about a rotational axis 102 ⁇ rotor 103 having a shaft 101, which is also referred to as the turbine rotor.
- an intake housing 104 a compressor 105, for example, a toroidal combustion chamber 110, in particular annular combustion chamber, with a plurality of coaxially arranged burners 107, a turbine 108 and the exhaust housing 109th
- a compressor 105 for example, a toroidal combustion chamber 110, in particular annular combustion chamber, with a plurality of coaxially arranged burners 107, a turbine 108 and the exhaust housing 109th
- the annular combustion chamber 110 communicates with an annular annular hot gas channel 111, for example.
- annular annular hot gas channel 111 for example.
- turbine stages 112 connected in series form the turbine 108.
- Each turbine stage 112 is formed, for example, from two blade rings . As seen in the direction of flow of a working medium 113, in the hot gas channel 111 of a row of guide vanes 115, a series 125 formed of rotor blades 120 follows.
- the guide vanes 130 are fastened to an inner housing 138 of a stator 143, whereas the moving blades 120 of a row 125 are attached to the rotor 103 by means of a turbine disk 133, for example.
- Coupled to the rotor 103 is a generator or work machine (not shown).
- air 135 is sucked by the compressor 105 through the intake housing and ver ⁇ seals.
- the 105 ⁇ be compressed air provided at the turbine end of the compressor is supplied to the burners 107, where it is mixed with a fuel.
- the mixture is then burned to form the working fluid 113 in the combustion chamber 110.
- the working medium 113 flows along the hot gas channel 111 past the guide vanes 130 and the rotor blades 120.
- the working medium 113 expands on the rotor blades 120 in a pulse-transmitting manner, so that the rotor blades 120 drive the rotor 103 and drive the machine connected to it ,
- the components exposed to the hot working medium 113 are subject to thermal loads during operation of the gas turbine 100.
- the guide vanes 130 and rotor blades 120 of the first turbine stage 112, viewed in the flow direction of the working medium 113, are subjected to the highest thermal stress in addition to the heat shield elements lining the annular combustion chamber 110.
- substrates of the components may have a directional structure, i. they are monocrystalline (SX structure) or have only longitudinal grains (DS structure).
- the components in particular for the turbine blade ⁇ 120, 130 and components of the combustion chamber 110, for example, iron-, nickel- or cobalt-based superalloys are used.
- Such superalloys are known, for example, from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435 or WO 00/44949.
- the guide vane 130 has an inner housing 138 of the turbine 108 facing guide vane root (not Darge here provides ⁇ ) and a side opposite the guide-blade root vane root.
- the vane head is the rotor 103 facing and fixed to a mounting ring 140 of the stator 143.
- FIG. 4 shows a perspective view of a rotor blade 120 or guide vane show ⁇ 130 of a turbomachine, which extends along a longitudinal axis of the 121st
- the turbomachine may be a gas turbine of an aircraft or a power plant for power generation, a steam turbine or a compressor.
- the blade 120, 130 has along the longitudinal axis 121 to each other, a securing region 400, an adjoining blade or vane platform 403 and a blade 406 and a blade tip 415.
- the vane 130 having at its blade tip 415 have a further platform (not Darge ⁇ asserted).
- a blade root 183 is formed, which serves for attachment of the blades 120, 130 to a shaft or a disc (not shown).
- the blade root 183 is designed, for example, as a hammer head. Other designs as Christmas tree or Schwalbenschwanzfuß are possible.
- the blade 120, 130 has for a medium which flows past the scene ⁇ felblatt 406 on a leading edge 409 and a trailing edge 412th
- the blade 120, 130 can be made by a casting process, also by directional solidification, by a forging process, by a milling process or combinations thereof.
- Workpieces with a monocrystalline structure or structures are used as components for machines which are exposed to high mechanical, thermal and / or chemical stresses during operation.
- Such monocrystalline workpieces takes place e.g. by directed solidification from the melt.
- These are casting processes in which the liquid metallic alloy is transformed into a monocrystalline structure, i. to the single-crystal workpiece, or directionally solidified.
- dendritic crystals are aligned along the heat flow and form either a columnar grain structure (columnar, ie grains that run the entire length of the workpiece and here, in common parlance, referred to as directionally solidified) or a monocrystalline structure, ie the whole workpiece be ⁇ is made of a single crystal.
- a columnar grain structure columnar, ie grains that run the entire length of the workpiece and here, in common parlance, referred to as directionally solidified
- a monocrystalline structure ie the whole workpiece be ⁇ is made of a single crystal.
- directionally solidified microstructures which means both single crystals that have no grain boundaries or at most small angle grain boundaries, and stem crystal structures that have probably longitudinal grain boundaries but no transverse grain boundaries. These second-mentioned crystalline structures are also known as directionally solidified structures.
- the blades 120, 130 may have protection layers 7 according to the invention against corrosion or oxidation.
- the density is preferably 95% of the theoretical
- thermal barrier coating which is preferably the outermost layer, and consists for example of Zr0 2 , Y2Ü3-Zr02, ie it is not, partially ⁇ or fully stabilized by yttria
- the thermal barrier coating covers the entire MCrAlX layer.
- Electron beam evaporation produces stalk-shaped grains in the thermal barrier coating.
- the heat insulating layer can comprise porous, micro- or macro-cracked compatible grains for better thermal shock resistance.
- the thermal barrier coating is therefore preferably more porous than the
- the blade 120, 130 may be hollow or solid. If the blade 120, 130 is to be cooled, it is hollow and also has, if necessary, film cooling holes 418 (indicated by dashed lines) on.
- the 5 shows a combustion chamber 110 of the gas turbine 100.
- the combustion chamber 110 is configured, for example, as so-called an annular combustion chamber, in which a plurality of in the circumferential direction about an axis of rotation 102 arranged burners 107 open into a common combustion chamber space 154, the flames 156 generate.
- the combustion chamber 110 is configured in its entirety as an annular structure, which is positioned around the axis of rotation 102 around.
- the combustion chamber 110 is designed for a comparatively high temperature of the working medium M of about 1000 ° C to 1600 ° C.
- the combustion chamber wall 153 is provided on its side facing the working medium M facing side with a formed from heat shield elements 155. liner.
- the heat shield elements 155 are then, for example, hollow and possibly still have cooling holes (not shown) which open into the combustion chamber space 154.
- Each heat shield element 155 made of an alloy is equipped on the working fluid side with a particularly heat-resistant protective layer (MCrAlX layer and / or ceramic coating) or is made of high-temperature-resistant material (solid ceramic blocks).
- These protective layers 7 may be similar to the turbine blades.
- a ceramic Wär ⁇ medämm harsh be present and consists for example of ZrÜ2, Y203-ZrÜ2, ie it is not, partially or fully ⁇ dig stabilized by yttrium and / or calcium oxide and / or magnesium oxide.
- Electron beam evaporation produces stalk-shaped grains in the thermal barrier coating.
- the heat insulating layer can comprise porous, micro- or macro-cracked compatible grains for better thermal shock resistance.
- Reprocessing means that turbines ⁇ blades 120, 130, heat shield elements have to be removed from 155, after ⁇ A set of protective layers (for example by sandblasting). This is followed by removal of the corrosion and / or oxidation layers or products.
- cracks in the turbine blade 120, 130 or the heat shield element 155 are also repaired. This is followed by a re-coating of the turbine blades 120, 130, heat shield elements 155 and a renewed use of the turbine blades 120, 130 or the heat shield elements 155.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Plasma & Fusion (AREA)
- General Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Coating By Spraying Or Casting (AREA)
- Turbine Rotor Nozzle Sealing (AREA)
- Physical Vapour Deposition (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
Abstract
Description
Claims
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP11724167.9A EP2576853B1 (de) | 2010-06-02 | 2011-05-31 | Legierung, schutzschicht und bauteil |
KR1020147019333A KR20140094659A (ko) | 2010-06-02 | 2011-05-31 | 합금, 보호층 및 부품 |
US13/701,155 US20130136948A1 (en) | 2010-06-02 | 2011-05-31 | Alloy, protective layer and component |
RU2013151464/02A RU2562656C2 (ru) | 2010-06-02 | 2011-05-31 | Сплав, защитное покрытие и конструкционная деталь |
CN201180027460.8A CN102933734B (zh) | 2010-06-02 | 2011-05-31 | 合金、保护层和构件 |
KR1020127031403A KR20130018906A (ko) | 2010-06-02 | 2011-05-31 | 합금, 보호층 및 부품 |
JP2013512872A JP2013530309A (ja) | 2010-06-02 | 2011-05-31 | 合金、保護層、及び部品 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP10005771.0 | 2010-06-02 | ||
EP10005771A EP2392684A1 (de) | 2010-06-02 | 2010-06-02 | Legierung, Schutzchicht und Bauteil |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2011151334A1 true WO2011151334A1 (de) | 2011-12-08 |
Family
ID=42806005
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2011/058965 WO2011151334A1 (de) | 2010-06-02 | 2011-05-31 | Legierung, schutzschicht und bauteil |
Country Status (7)
Country | Link |
---|---|
US (1) | US20130136948A1 (de) |
EP (4) | EP2392684A1 (de) |
JP (1) | JP2013530309A (de) |
KR (2) | KR20140094659A (de) |
CN (1) | CN102933734B (de) |
RU (1) | RU2562656C2 (de) |
WO (1) | WO2011151334A1 (de) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2012255196A (ja) * | 2011-06-10 | 2012-12-27 | Hitachi Ltd | Ni基超合金と、それを用いたガスタービンのタービン動・静翼 |
EP2637863A1 (de) * | 2011-01-06 | 2013-09-18 | Siemens Aktiengesellschaft | Legierung, schutzschicht und bauteil |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2474414A1 (de) * | 2011-01-06 | 2012-07-11 | Siemens Aktiengesellschaft | Legierung, Schutzschicht und Bauteil |
EP2557201A1 (de) | 2011-08-09 | 2013-02-13 | Siemens Aktiengesellschaft | Legierung, Schutzschicht und Bauteil |
US20150275677A1 (en) * | 2014-03-27 | 2015-10-01 | General Electric Company | Article for use in high stress environments having multiple grain structures |
ES2682362T3 (es) | 2015-05-05 | 2018-09-20 | MTU Aero Engines AG | Superaleación a base de níquel exenta de renio con baja densidad |
KR20190052053A (ko) * | 2016-09-12 | 2019-05-15 | 지멘스 악티엔게젤샤프트 | Nicocraly-합금, 분말 및 층 시스템 |
CN106987755A (zh) * | 2017-06-05 | 2017-07-28 | 北京普瑞新材科技有限公司 | 一种MCrAlY合金及其制备方法 |
US11819913B2 (en) | 2017-10-31 | 2023-11-21 | Oerlikon Metco (Us) Inc. | Wear resistant layer |
CN108915871B (zh) * | 2018-07-04 | 2021-05-25 | 智腾机械设备(上海)有限公司 | 一种发电式燃气轮机 |
CN108915872B (zh) * | 2018-07-04 | 2021-04-13 | 贵溪发电有限责任公司 | 一种提高火力发电厂发电效率的方法 |
Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4005989A (en) | 1976-01-13 | 1977-02-01 | United Technologies Corporation | Coated superalloy article |
US4034142A (en) | 1975-12-31 | 1977-07-05 | United Technologies Corporation | Superalloy base having a coating containing silicon for corrosion/oxidation protection |
WO1991001433A1 (en) | 1989-07-25 | 1991-02-07 | Allied-Signal Inc. | Dual alloy turbine blade |
EP0892090A1 (de) | 1997-02-24 | 1999-01-20 | Sulzer Innotec Ag | Verfahren zum Herstellen von einkristallinen Strukturen |
WO1999067435A1 (en) | 1998-06-23 | 1999-12-29 | Siemens Aktiengesellschaft | Directionally solidified casting with improved transverse stress rupture strength |
US6024792A (en) | 1997-02-24 | 2000-02-15 | Sulzer Innotec Ag | Method for producing monocrystalline structures |
WO2000044949A1 (en) | 1999-01-28 | 2000-08-03 | Siemens Aktiengesellschaft | Nickel base superalloy with good machinability |
EP1306454A1 (de) | 2001-10-24 | 2003-05-02 | Siemens Aktiengesellschaft | Rhenium enthaltende Schutzschicht zum Schutz eines Bauteils gegen Korrosion und Oxidation bei hohen Temperaturen |
EP1319729A1 (de) | 2001-12-13 | 2003-06-18 | Siemens Aktiengesellschaft | Hochtemperaturbeständiges Bauteil aus einkristalliner oder polykristalliner Nickel-Basis-Superlegierung |
EP1380672A1 (de) * | 2002-07-09 | 2004-01-14 | Siemens Aktiengesellschaft | Hochoxidationsbeständige Komponente |
EP1204776B1 (de) | 1999-07-29 | 2004-06-02 | Siemens Aktiengesellschaft | Hochtemperaturbeständiges bauteil und verfahren zur herstellung des hochtemperaturbeständigen bauteils |
EP0948667B1 (de) * | 1997-10-30 | 2004-12-22 | Alstom | Schutzbeschichtung für hochtemperatur |
EP1790743A1 (de) * | 2005-11-24 | 2007-05-30 | Siemens Aktiengesellschaft | Legierung, Schutzschicht und Bauteil |
EP1806418A1 (de) * | 2006-01-10 | 2007-07-11 | Siemens Aktiengesellschaft | Legierung, Schutzschicht zum Schutz eines Bauteils gegen Korrosion und Oxidation bei hohen Temperaturen und Bauteil |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS55161041A (en) * | 1979-05-29 | 1980-12-15 | Howmet Turbine Components | Covering material |
US4326011A (en) * | 1980-02-11 | 1982-04-20 | United Technologies Corporation | Hot corrosion resistant coatings |
JPS57155338A (en) * | 1981-03-23 | 1982-09-25 | Hitachi Ltd | Metallic body with alloy coating resistant to corrosion and thermal shock |
JPH0432546A (ja) * | 1990-05-28 | 1992-02-04 | Mitsubishi Heavy Ind Ltd | ガスタービン動翼補修方法 |
EP0786017B1 (de) * | 1994-10-14 | 1999-03-24 | Siemens Aktiengesellschaft | Schutzschicht zum schutz eines bauteils gegen korrosion, oxidation und thermische überbeanspruchung sowie verfahren zu ihrer herstellung |
CN1198964C (zh) * | 1997-10-30 | 2005-04-27 | 阿尔斯通公司 | 高温保护涂料 |
US20040180233A1 (en) * | 1998-04-29 | 2004-09-16 | Siemens Aktiengesellschaft | Product having a layer which protects against corrosion. and process for producing a layer which protects against corrosion |
RU2165475C2 (ru) * | 1999-05-27 | 2001-04-20 | Всероссийский научно-исследовательский институт авиационных материалов | Способ защиты стальных деталей машин от солевой коррозии |
DE60041951D1 (de) * | 1999-12-20 | 2009-05-20 | United Technologies Corp | Verwendung einer Kathode zur Vakuumbogenverdampfung |
EP1411210A1 (de) * | 2002-10-15 | 2004-04-21 | ALSTOM Technology Ltd | Verfahren zur Abscheidung einer ermüdungs- und oxydationsbeständigen MCrAlY-Beschichtung |
US7846243B2 (en) * | 2007-01-09 | 2010-12-07 | General Electric Company | Metal alloy compositions and articles comprising the same |
-
2010
- 2010-06-02 EP EP10005771A patent/EP2392684A1/de not_active Ceased
-
2011
- 2011-05-31 KR KR1020147019333A patent/KR20140094659A/ko not_active Application Discontinuation
- 2011-05-31 CN CN201180027460.8A patent/CN102933734B/zh active Active
- 2011-05-31 WO PCT/EP2011/058965 patent/WO2011151334A1/de active Application Filing
- 2011-05-31 KR KR1020127031403A patent/KR20130018906A/ko not_active Application Discontinuation
- 2011-05-31 JP JP2013512872A patent/JP2013530309A/ja active Pending
- 2011-05-31 RU RU2013151464/02A patent/RU2562656C2/ru active
- 2011-05-31 EP EP13000305.6A patent/EP2612949B1/de not_active Not-in-force
- 2011-05-31 US US13/701,155 patent/US20130136948A1/en not_active Abandoned
- 2011-05-31 EP EP13000306.4A patent/EP2612950A3/de not_active Withdrawn
- 2011-05-31 EP EP11724167.9A patent/EP2576853B1/de active Active
Patent Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4034142A (en) | 1975-12-31 | 1977-07-05 | United Technologies Corporation | Superalloy base having a coating containing silicon for corrosion/oxidation protection |
US4005989A (en) | 1976-01-13 | 1977-02-01 | United Technologies Corporation | Coated superalloy article |
WO1991001433A1 (en) | 1989-07-25 | 1991-02-07 | Allied-Signal Inc. | Dual alloy turbine blade |
EP0892090A1 (de) | 1997-02-24 | 1999-01-20 | Sulzer Innotec Ag | Verfahren zum Herstellen von einkristallinen Strukturen |
US6024792A (en) | 1997-02-24 | 2000-02-15 | Sulzer Innotec Ag | Method for producing monocrystalline structures |
EP0948667B1 (de) * | 1997-10-30 | 2004-12-22 | Alstom | Schutzbeschichtung für hochtemperatur |
WO1999067435A1 (en) | 1998-06-23 | 1999-12-29 | Siemens Aktiengesellschaft | Directionally solidified casting with improved transverse stress rupture strength |
WO2000044949A1 (en) | 1999-01-28 | 2000-08-03 | Siemens Aktiengesellschaft | Nickel base superalloy with good machinability |
EP1204776B1 (de) | 1999-07-29 | 2004-06-02 | Siemens Aktiengesellschaft | Hochtemperaturbeständiges bauteil und verfahren zur herstellung des hochtemperaturbeständigen bauteils |
EP1306454A1 (de) | 2001-10-24 | 2003-05-02 | Siemens Aktiengesellschaft | Rhenium enthaltende Schutzschicht zum Schutz eines Bauteils gegen Korrosion und Oxidation bei hohen Temperaturen |
EP1319729A1 (de) | 2001-12-13 | 2003-06-18 | Siemens Aktiengesellschaft | Hochtemperaturbeständiges Bauteil aus einkristalliner oder polykristalliner Nickel-Basis-Superlegierung |
EP1380672A1 (de) * | 2002-07-09 | 2004-01-14 | Siemens Aktiengesellschaft | Hochoxidationsbeständige Komponente |
EP1790743A1 (de) * | 2005-11-24 | 2007-05-30 | Siemens Aktiengesellschaft | Legierung, Schutzschicht und Bauteil |
EP1806418A1 (de) * | 2006-01-10 | 2007-07-11 | Siemens Aktiengesellschaft | Legierung, Schutzschicht zum Schutz eines Bauteils gegen Korrosion und Oxidation bei hohen Temperaturen und Bauteil |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2637863A1 (de) * | 2011-01-06 | 2013-09-18 | Siemens Aktiengesellschaft | Legierung, schutzschicht und bauteil |
JP2012255196A (ja) * | 2011-06-10 | 2012-12-27 | Hitachi Ltd | Ni基超合金と、それを用いたガスタービンのタービン動・静翼 |
Also Published As
Publication number | Publication date |
---|---|
EP2576853B1 (de) | 2014-10-29 |
EP2576853A1 (de) | 2013-04-10 |
KR20140094659A (ko) | 2014-07-30 |
RU2013151464A (ru) | 2015-05-27 |
JP2013530309A (ja) | 2013-07-25 |
EP2612949B1 (de) | 2014-12-24 |
CN102933734B (zh) | 2016-05-18 |
EP2612950A2 (de) | 2013-07-10 |
RU2562656C2 (ru) | 2015-09-10 |
EP2612949A2 (de) | 2013-07-10 |
EP2612949A3 (de) | 2014-02-19 |
EP2612950A3 (de) | 2014-02-19 |
KR20130018906A (ko) | 2013-02-25 |
EP2392684A1 (de) | 2011-12-07 |
CN102933734A (zh) | 2013-02-13 |
US20130136948A1 (en) | 2013-05-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2576853B1 (de) | Legierung, schutzschicht und bauteil | |
EP2458025B1 (de) | Legierung, Schutzschicht und Bauteil | |
EP2729302A1 (de) | Schichtsystem mit zweilagiger mcralx metallischer schicht | |
EP1834004A1 (de) | Legierung, schutzschicht zum schutz eines bauteils gegen korrosion und oxidation bei hohen temperaturen und bauteil | |
EP1798299B1 (de) | Legierung, Schutzschicht und Bauteil | |
EP1806418A1 (de) | Legierung, Schutzschicht zum Schutz eines Bauteils gegen Korrosion und Oxidation bei hohen Temperaturen und Bauteil | |
EP2710167B1 (de) | Legierung, schutzschicht und bauteil | |
EP1820883A1 (de) | Legierung, Schutzschicht und Bauteil | |
EP2474413A1 (de) | Legierung, Schutzschicht und Bauteil | |
WO2013007281A1 (de) | Schichtsystem mit zweilagiger metallischen schicht | |
EP2661370B1 (de) | Legierung, schutzschicht und bauteil | |
EP2611949B1 (de) | Nickel basis legierung, schutzschicht und bauteil | |
EP1790746B1 (de) | Legierung, Schutzschicht und Bauteil | |
EP2756107B1 (de) | Legierung, schutzschicht und bauteil | |
EP1806419B1 (de) | Legierung, Schutzschicht zum Schutz eines Bauteils gegen Korrosion und Oxidation bei hohen Temperaturen und Bauteil | |
WO2011086046A2 (de) | Legierung, schutzschicht und bauteil | |
EP2524063A1 (de) | Legierung, schutzschicht und bauteil | |
EP1818419A1 (de) | Legierung, Schutzschicht und Bauteil | |
EP1798300A1 (de) | Legierung, Schutzschicht zum Schutz eines Bauteils gegen Korrosion und/oder Oxidation bei hohen Temperaturen und Bauteil |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 201180027460.8 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 11724167 Country of ref document: EP Kind code of ref document: A1 |
|
DPE1 | Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101) | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2011724167 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 2013512872 Country of ref document: JP Kind code of ref document: A Ref document number: 20127031403 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 13701155 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1201006058 Country of ref document: TH |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 2013151464 Country of ref document: RU Kind code of ref document: A |