EP1734145A1 - Coating system for a component having a thermal barrier coating and an erosion resistant coating, method for manufacturing and method for using said component - Google Patents

Abstract

Gas- or steam-turbine component has a substrate layer (4) under a metal bonding layer (10), a ceramic heat insulation layer (7) and an upper anti-erosion layer (13). The materials making up the bonding layer and anti-erosion layer are the same or of nearly the same composition. Metal bonding layer and anti-erosion layer are an MCrAIX alloy. The bonding layer has 29-31% wt. Nickel, 27-29% wt. Chromium, 7-8% wt. Aluminum, 0.5-0.7% wt. Yttrium and 0.3-0.7% wt. Silicon; the residue is cobalt. The anti-erosion layer consists of 11-13% wt cobalt, 20-22% wt. Chromium, 10.5-11.5% aluminum, 0.3-0.5% Yttrium and 1.5-2.5% Wt. Rhenium; the residue is Nickel. Also claimed is a process to operate a commensurate steam turbine.

Description

The invention relates to a component with a thermal barrier coating and a metal erosion control layer according to claim 1, a method for the production according to claim 31 and a method for operating a steam turbine according to claim 32.

Thermal barrier coatings, which are applied to components, are known from the field of gas turbines, such as in the EP 1 029 115 are described.

Thermal barrier coatings allow components to be used at higher temperatures than the base material allows, or to extend service life.
Known base materials (substrates) for gas turbines allow operating temperatures of a maximum of 1000 ° C to 1100 ° C, whereas a coating with a thermal barrier coating allows operating temperatures of up to 1350 ° C.

The operating temperatures of components in a steam turbine are significantly lower, so that such demands are not made there.

From the EP 1 029 104 A It is known to apply a ceramic erosion protective layer on a ceramic thermal barrier coating of a gas turbine blade.

From the DE 195 35 227 A1 It is known to provide a heat-insulating layer in a steam turbine in order to be able to use materials with poorer mechanical properties, but which are more cost-effective, for the substrate to which the thermal barrier coating is applied.

The U.S. Patent 5,350,599 discloses an erosion resistant ceramic thermal barrier coating.

The US 2003/0152814 A1 discloses a thermal barrier coating system comprising a superalloy substrate, an aluminum oxide layer on the substrate, and a ceramic outer ceramic thermal barrier coating.

The EP 0 783 043 A1 discloses an erosion control layer consisting of aluminum oxide or silicon carbide on a ceramic thermal barrier coating.

The U.S. Patent 5,683,226 discloses a component of a steam turbine whose erosion resistance is improved.

The US 4,405,284 discloses an outer metallic layer that is significantly more porous than the underlying ceramic thermal barrier coating.

The EP 0 783 043 Al discloses in the discussion of the prior art that an erosion-resistant coating is constructed in two layers, namely an inner metallic layer and an outer ceramic layer.

The US 5,740,515 discloses a ceramic thermal barrier coating on which an outer hard ceramic silicide coating is applied.

The WO 00/70190 discloses a component in which an outer metal layer is applied, which has aluminum, which serves to increase the oxidation resistance of the component.

Due to impurities in a medium and / or high flow velocities of the flowing medium, which flows past components with a thermal barrier coating, a strong erosion of the thermal barrier coating occurs,

It is therefore an object of the invention to provide a component, a method for producing the component and a meaningful use of the layer system, which overcomes this problem.

The object is achieved by a component according to claim 1, by a method according to claim 31 and by a method according to claim 32.

In the subclaims further advantageous embodiments of the components according to the invention are listed.
The measures listed in the subclaims can be combined with each other in an advantageous manner.

In particular, in components of turbines, which are exposed to hot fluids, it often comes through scaling to a mechanical impact of detached scale particles on a brittle ceramic layer, which could lead to breakage of material, ie erosion. Although the ceramic layer is designed to survive thermal shocks, it is susceptible to localized mechanical stress because thermal shock affects the entire layer more globally.
Therefore, a metallic erosion control layer is of particular advantage because it is elastically and plastically deformable due to its ductility.

The thermal barrier coating is not necessarily used only for the purpose of shifting the range of use temperatures upwards, but the thermal expansion due to the temperature differences generated on the component is advantageously evened out and / or reduced. Thus, thermo-mechanical stresses can be avoided or at least reduced.

Embodiments are shown in the figures.

Figur 1

Anordnungsmöglichkeiten einer erfindungsgemäßen Wärmedämmschicht eines Bauteils,

Figur 2, 3

einen Gradienten der Porosität innerhalb der Wärmedämmschicht eines erfindungsgemäß ausgebildeten Bauteils,

Figur 4, 5

eine Dampfturbine,

Figur 6, 7, 8

weitere Ausführungsbeispiele eines erfindungsgemäßen ausgebildeten Bauteils.

Show it

FIG. 1

Possible arrangements of a thermal barrier coating of a component according to the invention,

FIG. 2, 3

a gradient of porosity within the thermal barrier coating of a component designed according to the invention,

FIG. 4, 5

a steam turbine,

FIGS. 6, 7, 8

Further embodiments of a trained component according to the invention.

FIG. 1 shows a first exemplary embodiment of a layer system 1 designed according to the invention for a component. In the following, the terms layer system 1 and component are used interchangeably when the component has the layer system 1.
The component 1 is preferably a component of a gas or steam turbine 300, 303 (FIG. 4), in particular a steam inflow region 333 of a steam turbine 300, a turbine blade 342, 354, 357 (FIG. 4) or a housing part 334, 335, 366 (FIGS. 4, 5) and consists of a substrate 4 (support structure) and a thermal insulation layer 7 applied thereto and an outer metallic erosion protection layer 13 on the thermal insulation layer 7.
Between the substrate 4 and the thermal barrier coating 7 at least one metallic bonding layer 10 is arranged.
The bonding layer 10 serves to protect against corrosion and / or oxidation of the substrate 4 and / or for better bonding of the thermal barrier coating 7 to the substrate 4. This is particularly the case when the thermal barrier coating 7 made of ceramic and the substrate 4 consists of a metal.
The erosion protection layer 13 consists of a metal or a metal alloy and protects the component from erosion and / or wear, as is the case in particular with steam turbines 300, 303 (Figure 4), which are subject to scaling, which is the case, and in which average flow velocities of about 50 m / s (ie 20 m / s - 100 m / s) and pressures of 350 to 400 bar occur.

The outer metallic erosion protection layer 13 (= outermost layer) is preferably formed denser than the thermal barrier coating 7.
Denser in this context means that the porosity of the outer metallic erosion protection layer 13 is absolutely higher by at least 1%, in particular at least 3% higher than that of the thermal barrier coating 7 (for example ρ (7) = 90%, ie ρ (13) ≥ 91%. , in particular ≥ 93%).
The density of the thermal barrier coating 7 is preferably 80% - 95% of the theoretical density, wherein the density ρ of the metallic erosion control layer 13 is preferably at least 96%, preferably 98% of the theoretical density.

By metal is meant not only elemental metals, but also alloys, mixed crystals or intermetallic compounds.

The bonding layer 10 and the erosion protection layer 13 according to the invention have the same or similar composition.
Same composition means that both layers 10, 13 have the same elements with the same proportions (identity), preferably of a MCrAlX alloy or of SC 21, SC 23 or SC 24. By preferably using the same composition for the erosion control layer 13, the Procurement simplified and also the corrosion behavior of the substrate 4 significantly improved.

Similar composition means that both layers 10, 13 have the same elements, but with slightly different proportions, ie differences of at most 3% per element (for example, layer 10 has chromium content of 30%, the layer 13 can have chromium contents of at least 27% (30-3) or at most 33% (30 + 3) and up to 1% by weight at least one further element can be present.

The SC 21 consists of (in wt%) 29% - 31% nickel, 27% - 29% chromium, 7% - 8% aluminum, 0.5% - 0.7% yttrium, 0.3% - 0.7 % Silicon and balance cobalt.

The SC 23 consists of (in wt%) 11% - 13% cobalt, 20% - 22% chromium, 10.5% - 11.5% aluminum, 0.3% - 0.5% yttrium, 1.5% - 2.5% rhenium and the rest nickel.

The SC 24 consists of (in wt%) 24% - 26% cobalt, 16% - 18% chromium, 9.5% - 11% aluminum, 0.3% - 0.5% yttrium, 1.0% - 1 , 8% rhenium and the rest nickel.

The wear / erosion protection layer 13 preferably consists of alloys based on iron, chromium, nickel and / or cobalt or, for example, NiCr 80/20 or NiCrSiB with admixtures of boron (B) and silicon (Si) or NiAl (for example: Ni: 95wt%, Al 5wt%).

In particular, a metallic erosion protection layer 13 can be used in steam turbines 300, 303, since the operating temperatures in steam turbines in the steam inflow region 333 are a maximum of 450 ° C., 550 ° C., 650 ° C., 750 ° C. or B 50 ° C.

Preferably, a temperature of 750 ° C is used.

For such temperature ranges, there are enough metallic layers that have a sufficiently large necessary erosion protection over the service life of the component 1 with good oxidation resistance.

Metallic erosion protection layers 13 in gas turbines on a ceramic thermal barrier coating 7 within the first stage of the turbine or within the combustion chamber will not executed, since metallic erosion protection layers 13 as an outer layer, the operating temperatures of up to 1350 ° C can not stand.

• 11,5% bis 20,0% Chrom,
• 0,3% bis 1,5% Silizium,
• 0,0% bis 1,0% Aluminium,
• 0,0% bis 0,7% Yttrium und/oder zumindest ein äquivalentes Metall aus der Gruppe umfassend Scandium und die Elemente der Seltenen Erden,
• Rest Eisen, Kobalt und/oder Nickel sowie herstellungsbedingte Verunreinigungen.

The bonding layer 10 for protecting a substrate 4 against corrosion and oxidation at a high temperature has, for example, substantially the following elements (indication of the parts in wt% wt%):

• 11.5% to 20.0% chromium,
• 0.3% to 1.5% silicon,
• 0.0% to 1.0% aluminum,
• From 0.0% to 0.7% yttrium and / or at least one equivalent metal from the group comprising scandium and the rare earth elements,
• Remainder iron, cobalt and / or nickel as well as production-related impurities.

• 0,5% bis 1,0% Silizium,
• 0,1% bis 0,5% Aluminium,
• 0,0% bis 0,7% Yttrium und/oder zumindest ein äquivalentes Metall aus der Gruppe umfassend Scandium und die Elemente der Seltenen Erden,
• Rest Eisen und/oder Kobalt und/oder Nickel sowie herstellungsbedingte Verunreinigungen.

In particular, the metallic bonding layer 10 consists of 12, 5% to 14.0% chromium,

• 0.5% to 1.0% silicon,
• 0.1% to 0.5% aluminum,
• From 0.0% to 0.7% yttrium and / or at least one equivalent metal from the group comprising scandium and the rare earth elements,
• Remainder iron and / or cobalt and / or nickel as well as production-related impurities.

It is preferred if the remainder of these two bonding layers 10 is only iron.

The composition of the iron-based attachment layer 10 exhibits particularly good properties, so that the attachment layer 10 is outstandingly suitable for application to ferritic substrates 4.
The coefficients of thermal expansion of substrate 4 and bonding layer 10 can be very well matched to each other (only up to 10% difference) or even equal, so there is no thermally induced stress build-up between substrate 4 and bonding layer 10 comes (thermal mismatch), which could cause a spalling of the bonding layer 10.
This is particularly important because in ferritic materials often no heat treatment for diffusion bonding is performed, but the bonding layer 10 (ferritic) largely or only by adhesion to the substrate 4 adheres.

The composition of the outer erosion control layer 13 is selected to have a high ductility. High ductility in this context means that elongation at break of 5% (an elongation of 5% leads to the formation of cracks) at the service temperature.

Such an erosion protection layer 13 with such a ductility can be present directly on a substrate 4 or on a ceramic thermal barrier coating 7, wherein the composition of the bonding layer 10 then no longer plays a role.

The heat-insulating layer 7 is in particular a ceramic layer, which consists for example at least partially of zirconium oxide (partially stabilized or fully stabilized by yttrium oxide and / or magnesium oxide) and / or at least partially of titanium oxide and is for example thicker than 0.1 mm. Thus, thermal barrier coatings 7 consisting of 100% of either zirconia or titanium oxide can be used.

The ceramic layer 7 can be applied by known coating methods such as atmospheric plasma spraying (APS), vacuum plasma spraying (VPS), low-pressure plasma spraying (LPPS) and by chemical or physical coating methods (CVD, PVD).

The substrate 4 is preferably a steel or other iron-based alloy (for example 1% CrMoV or 10-12% chromium steels) or a nickel- or cobalt-based superalloy.

In particular, the substrate 4 is a ferritic base alloy, a steel or a nickel or cobalt-based superalloy, in particular a 1% CrMoV steel or a 10 to 12 percent chromium steel.

• 1% bis 2%Cr Stahl für Wellen (309, Fig. 4):
  wie z.B. 30CrMoNiV5-11 oder 23CrMoNiWV8-8 oder
• 1% bis 2%Cr Stahl für Gehäuse (Fig. 4, bspw. 335):
  G17CrMoV5-10 oder G17CrMo9-10 oder
• 10% Cr-Stahl für wellen (309, Fig. 4):
  X12CrMoWVNbN10-1-1 ,
• 10% Cr-Stahl für Gehäuse (Fig. 4, bspw. 335):
  GX12CrMoWVNbN10-1-1 oder GX12CrMoVNbN9-1.

Further advantageous ferritic substrates 4 of the layer system 1 consist of a

• 1% to 2% Cr Steel for Shafts (309, Fig. 4):
  such as 30CrMoNiV5-11 or 23CrMoNiWV8-8 or
• 1% to 2% Cr steel for housing (Fig. 4, eg 335):
  G17CrMoV5-10 or G17CrMo9-10 or
• 10% Cr steel for shafts (309, Fig. 4):
  X12CrMoWVNbN10-1-1,
• 10% Cr-steel for housing (Fig. 4, eg 335):
  GX12CrMoWVNbN10-1-1 or GX12CrMoVNbN9-1.

For the best possible mode of action of the thermal barrier coating 7, the thermal barrier coating 7 at least partially has a certain open and / or closed porosity.

The erosion protection layer 13 preferably has a higher density than the thermal barrier coating 7, so that it 13 has a higher erosion resistance.

The metallic erosion protection layer 13 has a very low porosity and in particular has a lower roughness, so that a good resistance to erosive erosion is achieved.

1. 1. Verwendung eines Spritzpulvers beim thermischen Spritzen der Erosionsschutzschicht 13, das eine möglichst geringe Korngröße aufweist,
2. 2. Verdichtung der äußeren metallischen Erosionsschutzschicht 13 nach dem Spritzen durch einen Strahlvorgang, beispielsweise durch Bestrahlen mit Glasperlen oder Stahlkies oder anderen mechanischen Verdichtungs- oder Glättungsverfahren (rollieren, gleitschleifen),
3. 3. Verschließen der offenen Poren durch Penetrationsmittel,
4. 4. Wärmebehandlung des gesamten Systems,
5. 5. Aufschmelzen oder Umschmelzen der obersten Lage oder der kompletten metallischen Erosionsschutzschicht.

The lower porosity and roughness of the metallic erosion control layer can be achieved by various techniques:

1. 1. Use of a spray powder during thermal spraying of the erosion protection layer 13, which has the smallest possible grain size,
2. 2. densification of the outer metallic erosion protection layer 13 after spraying by a blasting process, for example by irradiation with glass beads or steel gravel or other mechanical compacting or smoothing processes (rolling, sliding),
3. 3. closing of the open pores by penetration means,
4. 4. heat treatment of the entire system,
5. 5. melting or remelting the uppermost layer or the complete metallic erosion protection layer.

In contrast, the bonding layer 10 located between the substrate and the thermal barrier coating is made to have sufficiently high roughness with undercuts to achieve good adhesion of the thermal barrier coating to the tie layer 10 13 a much coarser powder can be used during the injection process.

FIG. 2 shows a porous thermal barrier coating 7 with a gradient of porosity.
In the thermal barrier coating 7 pores 16 are present. In the direction of an outer surface, the density ρ of the thermal barrier coating 7 increases.
Thus, the layer 7 can be used in the region of greater porosity for thermal insulation and, where appropriate, for erosion protection in the area of lower porosity.

Thus, there is preferably a greater porosity towards the bonding layer 10 than in the region of an outer surface or the contact surface with the erosion protection layer 13.

In FIG. 3, the gradient in the density ρ of the thermal barrier coating 7 runs opposite to that in FIG. 2.

The erosion protection layer 13 is preferably applied only locally, and preferably there on the component 1, where the angle of impact of eroding particles on the component 1 between 60 ° and 120 °, preferably between 70 ° and 110 ° or preferably by 80 ° and 100 ° , It is particularly useful to coat the sites which have an angle of incidence of 90 ° +/- 2 ° of the eroding particles. In this almost vertical impact of eroding particles on the surface of a component 1, a metallic erosion protection layer 13 offers the best erosion protection.

FIG. 4 shows by way of example a steam turbine 300, 303 with a turbine shaft 309 extending along a rotation axis 306.

The steam turbine has a high-pressure turbine section 300 and a medium-pressure turbine section 303, each having an inner housing 312 and an outer housing 315 enclosing this. The high-pressure turbine part 300 is designed, for example, in Topfbauart. The medium-pressure turbine section 303 is double-flow. It is also possible for the medium-pressure turbine section 303 to be single-flow. Along the axis of rotation 306, a bearing 318 is arranged between the high-pressure turbine section 300 and the medium-pressure turbine section 303, the turbine shaft 309 having a bearing region 321 in the bearing 318. The turbine shaft 309 is on another bearing 324 adjacent to the high pressure turbine section 300. In the area of this bearing 324, the high-pressure turbine section 300 has a shaft seal 345. The turbine shaft 309 is sealed from the outer housing 315 of the medium-pressure turbine section 303 by two further shaft seals 345. Between a high-pressure steam inflow region 348 and a steam outlet region 351, the turbine shaft 309 in the high-pressure turbine section 300 has the high-pressure impeller blade 354, 357. This high-pressure bladed runner 354, 357, together with the associated blades, not shown, represents a first blading region 360. The middle-pressure blast turbine 303 has a central steam inflow region 333. Associated with the steam inflow region 333, the turbine shaft 309 has a radially symmetrical wave shield 363, a cover plate, on the one hand for dividing the steam flow into the two flows of the medium-pressure turbine section 303 and for preventing direct contact of the hot steam with the turbine shaft 309. The turbine shaft 309 has in the medium-pressure turbine section 303 a second blading area 366 with the medium-pressure blades 354, 342. The hot steam flowing through the second blading area 366 flows out of the medium-pressure turbine section 303 from a discharge connection 369 to a downstream low-pressure turbine, not shown.

The turbine shaft 309 is composed of two sub-turbine shafts 309a and 309b, which are fixedly connected to one another in the region of the bearing 318.

In particular, the steam inflow region 333 has a heat insulation layer 7 and an erosion protection layer 13.

FIG. 5 shows an enlarged view of a region of the steam turbine 300, 303.
In the region of the inflow region 333, the steam turbine 300, 303 consists of an outer housing 334, against which temperatures between 250 ° and 350 ° C. are applied.
Temperatures of 450 ° to 800 ° C. prevail at the inflow region 333 as part of an inner housing 335.
This results in a temperature difference of at least 200 ° C.
On the inner housing 335, which abut the high temperatures, the thermal barrier coating 7 is applied to the erosion protection layer 13 on the inside 336 (on the outside 337, for example, not).
The thermal barrier coating 7 is present locally only on the inner housing 335 (and not in the blading area 366, for example).
By the application of a thermal barrier coating 7 with the erosion protection layer 13, the heat input into the inner housing 335 is reduced, so that the thermal expansion behavior is influenced. As a result, the entire deformation behavior of the inner housing 335 and the Dampfeinströmbereichs 333 can be controlled. This can be done by a variation of the thickness of the thermal barrier coating 7 or the application of different materials at different locations of the surface of the inner housing 335th
Likewise, the porosity at different locations of the inner housing 335 may be different.
The thermal barrier coating 7 may be applied locally, for example in the inner housing 335 in the region of the inflow region 333.
Likewise, the thermal barrier coating 7 can be applied locally only in the blading area 366 (FIG. 6).
Especially in the inflow region 333, the use of an erosion protection layer 13 is required.

If the thermal barrier coating 7 (TBC) with erosion protection layer 13 is present in the inflow region 333, a Thermal insulation layer 7 without erosion protection layer in the blading area 366 and / or the turbine blades be present. inflow blading turbine blade TBC Yes + 13 No No TBC Yes + 13 Yes No TBC Yes + 13 No Yes TBC Yes + 13 Yes + 13 No TBC Yes Yes + 13 No TBC Yes No Yes + 13

FIG. 7 shows a further exemplary embodiment of a component 1 according to the invention.
Here, the thickness of the thermal barrier coating 7 in the inflow region 333 is made thicker than in the blading region 366 of the steam turbine 300, 303.
Due to the locally different thickness of the thermal barrier coating 7, the heat input and thus the thermal expansion and thus the expansion behavior of the inner housing 334, consisting of the inflow region 333 and the blading region 366, controlled.
Since higher temperatures prevail in the inflow region 333 than in the blading region 366, the thicker heat-insulating layer 7 in the inflow region 333 reduces the heat input into the substrate 4 more than in the blading region 366, where lower temperatures prevail. Thus, the heat input in both the inflow region 333 and subsequent blading region 366 can be kept approximately equal, so that the thermal expansion is approximately equal,

Likewise, in the region of the inflow region 333, a different material may be present than in the blading region 366. The thermal barrier coating 7 is applied here in the entire hot region, ie globally, and has the erosion protection layer 13.

FIG. 8 shows a further example of application for the use of a thermal barrier coating 7.
The component 1, in particular a housing part, is here a valve housing 31, into which a hot steam flows through an inlet channel 46.
The inflow passage 46 causes a mechanical weakening of the valve housing.
The valve housing 31 consists for example of a cup-shaped housing part 34 and a lid 37th
Within the housing part 31, a valve consisting of a valve plug 40 and a spindle 43 is present.
As a result of component creeping, a non-uniform axial deformation of the housing 31 and cover 37 occurs. The valve housing 31 would expand axially more strongly in the region of the channel 46, so that tilting of the cover with the spindle 43 occurs, as indicated by dashed lines. As a result, the valve cone 34 no longer sits properly, so that the tightness of the valve is reduced.
By applying a thermal barrier coating 7 on an inner side 49 of the housing 31, a homogenization of the deformation behavior is achieved, so that both ends 52, 55 of the housing 31 and the cover 37 expand uniformly.

Overall, the application of the thermal barrier coating 7 serves to control the deformation behavior and thus to ensure the tightness of the valve.
The thermal barrier coating 7 in turn has the erosion protective layer 13.

Claims (34)

Layer system for a component (1, 31, 334, 335, 342, 354, 357, 366)
in particular for a steam turbine (300, 303),
at least consisting of
a substrate (4),
a metallic bonding layer (10),
a thermal barrier coating (7) on the metallic bonding layer (10),
in particular a ceramic thermal barrier coating (7),
and an outer metallic erosion protection layer (13) on the thermal barrier coating (7),
characterized in that
the bonding layer (10) and the erosion control layer (13) have the same or similar composition. Layer system according to claim 1,
characterized in that
the material of the bonding layer (10) and the erosion control layer (13) is an MCrAlX alloy. Layer system according to claim 1 or 2,
characterized in that
the material of the bonding layer (10) (in wt%), in particular also the material of the erosion protection layer (13),
out 29% - 31% Nickel, 27% - 29% Chrome, 7% - 8th% Aluminum, 0.5% - 0.7% Yttrium, 0.3% - 0.7% silicon and balance cobalt exists. Layer system according to claim 1 or 2,
characterized in that
the material of the bonding layer (10) (in wt%), in particular also the material of the erosion protection layer (13),
out 11% - 13% Cobalt, 20% - 22% Chrome, 10.5% - 11.5% Aluminum, 0.3% - 0.5% Yttrium, 1.5% - 2.5% rhenium and the rest is nickel. Layer system according to claim 1 or 2,
characterized in that
the material of the bonding layer (10) (in wt%), in particular also the material of the erosion protection layer (13),
out 24% - 26% Cobalt, 16% - 18% Chrome, 9.5% - 11% Aluminum, 0.3% - 0.5% Yttrium, 1.0% - 1.8% rhenium and the rest is nickel. Layer system according to claim 1 or 2,
characterized in that
the material of the bonding layer (10) (in wt%), in particular also the material of the erosion protection layer (13),
out 11.5% - 20% Chrome, 0.3% - 1.5% Silicon, 0% - 1% Aluminum, 0% - 4% yttrium as well as remainder iron exists. Layer system according to claim 6,
characterized in that
the material of the bonding layer (10) (in wt%), in particular also the material of the erosion protection layer (13),
out 12.5% - 14% chromium, 0.5% - 1.0% silicon, 0.1% - 0.5% aluminum, 0% - 4% yttrium, as well as remainder iron exists. Layer system according to claim 1 or 2,
characterized in that
the erosion protection layer (13) and the bonding layer (10) made of an iron, nickel, chromium or cobalt-based alloy,
especially NiCr80 / 20. Layer system according to claim 1,
characterized in that
the erosion protection layer (13) and the bonding layer (10) consist of a nickel-chromium alloy with admixtures of silicon (Si) and / or boron (B) (NiCrSiB). Layer system according to claim 1,
characterized in that
the erosion protection layer (13) and the bonding layer (10) consist of a nickel-aluminum alloy. Layer system according to one of claims 1 to 10,
characterized in that
the bonding layer (10) and the erosion control layer (13) have the same composition. Layer system according to claim 1,
characterized,
that the erosion protection layer (13) has a lower porosity than the thermal barrier coating (7), that in particular the difference in density is at least 1%, in particular at least 3%. Layer system according to claim 1 or 12,
characterized in that
the erosion control layer (13) has a density of at least 96%,
especially 98%,
the theoretical density of the erosion control layer (13). Layer system according to claim 1, 12 or 13,
characterized in that
the density of the thermal barrier coating (7) is 80% - 95% of the theoretical density of the thermal barrier coating (13). Layer system according to claim 1, 12 or 14,
characterized in that
the thermal barrier coating (7) is at least partially porous. Layer system according to claim 12, 14 or 15,
characterized in that
the thermal barrier coating (7) has a gradient in porosity. Layer system according to claim 16,
characterized in that
the porosity of the thermal barrier coating (7) in the outer region of the thermal barrier coating (7) is greatest. Layer system according to claim 16,
characterized in that
the porosity of the thermal barrier coating (7) in the outer region of the thermal barrier coating (7) is smallest. Layer system according to claim 1, 2, 8, 9 or 10,
characterized in that
the material of the metallic erosion protection layer (13) has a high ductility,
in particular has an elongation at break of 5%. Layer system according to claim 1,
characterized in that
the layer system (1) is a housing part (31, 334, 335, 366) of a gas or steam turbine (300, 303). Layer system according to claim 20,
characterized in that
the layer system (1) is a turbine housing (366) or a valve housing (31). Layer system according to claim 1,
characterized in that
the layer system (1) is a turbine blade (342, 354, 357). Layer system according to claim 1, 19, 20, 21 or 22,
characterized in that
the erosion protection layer (13) there,
especially only there,
is present on the component (1),
where an angle of impact of eroding particles on the component (1) is between 60 ° -120 °,
in particular between 70 ° and 110 °. Layer system according to one of claims 1 or 20 to 23,
characterized,
that the layer system (1) consists of a substrate (4) on which (4) the thermal barrier coating (7) is present, and
that the substrate (4) is formed from a nickel, cobalt or, especially, iron-based alloy. Layer system according to claim 1, 12, 14 or 24,
characterized in that
the thermal barrier coating (7) consists at least partially, in particular entirely of zirconium oxide (ZrO ₂ ). Layer system according to claim 1, 12, 14, 24 or 25,
characterized in that
the thermal barrier coating (7) consists at least partially, in particular entirely of titanium oxide (TiO ₂ ). Layer system according to claim 1,
characterized in that
the layer system (1) is applied in the inflow region (333) and in the blading region (366) of a steam turbine (300, 303). Layer system according to claim 1,
characterized in that
the layer system (1) is applied only in the inflow region (333) of a steam turbine (300, 303). Layer system according to claim 1,
characterized in that
the layer system (1) is applied only in the blading area (366) of a steam turbine (300, 303). Layer system according to claim 1,
characterized in that
the bonding layer (10) the thermal barrier coating (7) and
the erosion protection layer (13) is applied to refurbished components (1). Method for producing a component according to one of claims 1 to 30,
characterized in that
the Erosionsschutzachicht (13) after application to the thermal barrier coating (17) is compressed. Method for operating a steam turbine (300, 303)
wherein steam with eroding particles flows in the steam turbine (300, 303),
which hit inner surfaces of the steam turbine (303, 303),
wherein at least the inner surfaces of the steam turbine (300, 303) are provided with a layer system (1),
in particular according to one or more of claims 1 to 31,
on which the particles impinge at an angle of 60 ° - 120 °, in particular 70 ° - 110 °. Method according to claim 32,
characterized in that
the inner surfaces of the steam turbine (300, 303) being provided with a layer system (1),
in particular according to one or more of claims 1 to 31,
on which the particles impinge at an angle of 80 ° - 100 °, in particular by 90 °. A method according to claim 32 or 33,
characterized in that
only the inner surfaces of the steam turbine (300, 303) with a layer system (1),
in particular according to one or more of claims 1 to 31,
on which the particles impinge at an angle of 80 ° - 100 °, in particular by 90 °.

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