WO2015169513A1

WO2015169513A1 - Arrangement and method for constructing a coating layer in layers

Info

Publication number: WO2015169513A1
Application number: PCT/EP2015/057063
Authority: WO
Inventors: Bernd Burbaum
Original assignee: Siemens Aktiengesellschaft
Priority date: 2014-05-06
Filing date: 2015-03-31
Publication date: 2015-11-12
Also published as: DE102014208435A1

Abstract

The invention relates to an arrangement for constructing a coating layer in layers from a highly temperature-resistant superalloy, comprising a substrate (3). A building material (8) which contains the highly temperature-resistant superalloy is deposited on the substrate (3). Multiple individual energy sources which point in the direction of the building material (8) are arranged in an annularly symmetrical manner about at least one energy source which points in the direction of the building material in order to produce a molten bath (7) in the building material (8) section by section. All the energy sources can be controlled separately. The invention further relates to a method for constructing a coating layer in layers.

Description

description

Arrangement and method for layering a job layer

The invention relates to an arrangement and method for the layered creation of a coating layer of highly heat-resistant superalloy comprising a substrate, wherein a high heat resistant superalloy-containing building material is applied to the substrate.

Blades of gas turbines are exposed to high temperatures and heavy mechanical loads during operation. For such components, therefore, preference is given to using highly heat-resistant nickel-base superalloys which can be strengthened by precipitating a γ 'phase. However, over time, cracks can occur in the blades that continue to expand over time. Such cracks can arise, for example, due to the extreme mechanical stress during the operation of a gas turbine, but they can also already occur during the production process. Since the production of turbine blades and other workpieces from such superalloys is expensive and expensive, it is endeavored to produce as little waste as possible in the production and to ensure a long life of the products produced.

Gas turbine blades in operation are regularly serviced and, if necessary, exchanged if due to operational stress proper functioning can no longer be readily ensured. In order to enable a further use of exchanged turbine blades, they are worked up again as far as possible. They can then be used again in a gas turbine. In the context of such a reprocessing a cladding of a building material onto the damaged ^¬-like workpiece in the damaged areas can for example be necessary to restore the original wall thickness or shape of the workpiece again manufacture. This can optionally be done after removal of the damaged area, for example by milling.

Turbine blades that have already cracked during the manufacturing process can also be used in this way

Cladding be made ready for use, so that the Committee can be reduced during manufacture.

However, many high-temperature superalloys are difficult to weld using conventional welding techniques. The building materials produced often have unsatisfactory material properties, which can be attributed to the formation of a columnar solidification front during the solidification of the material melted during the build-up welding.

One solution offers a pendulum motion of the laser beam. To implement this technology pendulum lateral acceleration Be ^¬ machine technology (machine tool) is neces- dig. Due to the acceleration holding the used

Machine tool, the possibilities of a pendulum Techno logy can ^¬ (frequency / amplitude) are severely limited.

It is therefore a first and a second object of the invention to provide an arrangement and a method which solve the above-mentioned problem.

The first object is achieved by specifying a Anord ^¬ voltage for layerwise create a coating layer made of highly heat-resistant superalloy article comprising a substrate with a highly heat-resistant superalloy containing structure Mate ^¬ rial is applied to the substrate, applied to the portion ^¬ comprise generating a molten bath in the Building material a plurality of individual pointing in the direction of the applied building material energy sources are annular symmet ^¬ rically arranged around at least one pointing in the direction of the applied building material energy source, all energy sources are separately controlled. The second object is achieved by specifying a procedural ^¬ proceedings for layerwise create a coating layer made of highly heat-resistant super alloy on a substrate, wherein a highly heat-resistant superalloy containing build material is applied to the substrate, by several, a ^¬ zelne in the direction of the applied building material a ring-shaped bath in the applied build-up material is generated in sections, with all Energiequel ^¬ len are driven separately, so that there is a ^{kreisförmi ¬} ge processing ^zone for the molten bath. A plurality of individual energy sources are arranged in an annular symmetrical manner around at least one energy source pointing in the direction of the applied build-up material, resulting in a circular processing zone for a molten bath.

Of course, the annular energy sources may also be arranged to provide a first annular array of above ^¬ be written energy source. The energy sources can emit laser radiation, which overlap coaxially. The advantages of this arrangement or this method are that each individual energy source, which is hereinafter referred to as La ^¬ serquelle with laser radiation, separately

can be controlled (laser power), so that locally to the intensity distribution at the interaction zone of the laser radiation can be influenced with the applied building material.

Advantageously, the power sources are evenly ^¬ ring-shaped symmetrically arranged one facing in the direction of the listed attached build material source of energy to at least. The energy sources can also be arranged in an annular symmetrical manner about at least one energy source pointing in the direction of the applied build-up material, wherein the annular ones symmetrical about at least one oriented in the direction of the applied building material energy source arranged energy ^¬ sources may have a uniform distance to this at least one energy source.

Advantageously, thus, a pendant overall strategy is samtbearbeitungszone possible by the individual control of the La ^¬ serstrahlquellen, whereby lateral movement of the machine tool is unnecessary. By Pendelbewe ^¬ supply a constantly changing solidification function is generated, whereby the grain growth is interrupted during the solidification of the melt and the microstructure solidifies fine grained. The fine graininess of the microstructure distributes the remaining residual welding stresses to the grain boundaries so that cracks in the weld or in the weld metal are avoided. The invention can now be dispensed with a lateral acceleration of the machine technology (machine tool), which is a prerequisite for the implementation of a Pendeltechnolo- technology. The strong limitation of the possibilities Mög ^¬ a pendulum technology in terms of frequency and / or amplitude are thus canceled. Due to the annular arrangement of the individual laser beams, a direction-independent material processing is advantageously made possible, since, for example, the individual beam sources can be regulated by means of a change of travel.

The subclaims list further advantageous measures which can be combined with one another as desired in order to achieve further advantages.

Preferably, the energy sources, in particular the laser beam sources ^¬, pointing in the direction of the applied laser beams on the building material, wherein the energy sources are arranged so reasonable that mutually coaxial energy rays arise. The energy beams may overlap. Advantageously, the energy sources Laserstrahlquel ^¬ len. These preferably have a maximum laser power of 50-100 W. Laser beam sources with a maximum laser power of 50-100 W, which are particularly cost-effective, are used.

Preferably, a controller for controlling the Energiequel ^¬ len is provided. The energy sources comprise energy beams pointing in the direction of the applied build-up material, with a propagation center axis and a diameter, the diameter being variable. For example, a controller for controlling the individual energy sources and / or for modulating the power of the individual energy sources may be provided. The diameter of the individual energy sources can be adjustable, for example, by means of the zoom telescope.

Preferably, the energy sources in the direction of the applied building material comprise energy beams pointing with a propagation center axis. In addition, a material supply treadmill is intended, wherein the material feed is arranged coaxially to Ausbreitungsmit ^¬ center axis. In a further preferred Substituted ^¬ staltung the energy beams are guided through the material feed coaxial. Preferably, the material supply is a Pul ^¬ verdüse. The jets are therefore coupled coaxially through a powder nozzle into the molten bath. This has a compact design to the advantage.

In an exemplary embodiment, the energy sources comprise energy beams pointing in the direction of the applied build-up material, the energy beams at least partially overlapping at least on the applied build-up material. This means that the intensity distributions can overlap area ^¬ pen. As a result, different intensity distributions can be produced.

Alternatively, the energy sources in the direction of the applied building material include facing energy beams, wherein do not overlap the energy beams on the applied build material.

Preferably, nickel- or cobalt-based superalloys are used as the substrate. This is particularly well suited for use in power plants, especially turbines.

The welding process can be remelting or build-up welding. There is one for both methods

Melt and a solidification front.

Preferably, a separate control of the individual energy sources nen ^¬ a local heat treatment, in particular a preheating and / or reheating of the building material allows. In general, when laser beam deposition welding by the control of the individual laser beam sources, a local heat treatment, in particular with regard to

Preheating / reheating possible. By preheating / reheating, for example, a structure formation with application-specific properties can be secured.

Preferably is influenced by a separate control of the individual energy sources and pointing in the direction of the applied building material energy beam locally the intensity ^¬ distribution at the zone of interaction of the energy beams with the applied building material.

The inventive method is particularly suitable for the machining ^¬ processing of gas turbine components such as guide vanes or blades. Therefore, the substrate is preferably a gas turbine blade, wherein the applied building material is applied to a tip of the gas turbine blade or on an upper or Sei ^¬ tenfläche a blade platform of the gas turbine blade. The tip of a gas turbine blade and the blade platform are exposed to the greatest wear during operation of a gas turbine.

Further features, properties and advantages of the present invention will become apparent from the following description. With reference to the accompanying figures. In it show schematically:

1 shows a plan view of an inventive arrangement, Figure 2 shows a cross section of an inventive arrangement.

Figures 1 and 2 show an arrangement of a welding process, in particular a laser welding process, by means of which the invention is explained in a non-limited way.

The arrangement and the method are therefore not restricted to laser welding methods, but also apply to electron welding methods and other plasma welding methods with corresponding energy sources.

In order to implement an oscillation technology a lateral acceleration Be ^¬ machine technology (machine tool) is necessary. Due to the acceleration of the machine tool holding the opportunities used a pendulum Techno logy ^¬ (frequency / amplitude) can be greatly limited. 1 shows a coating technology according to the invention. 1 shows an arrangement for a layer-wise to create a plating layer 6 (Figure 2) of highly heat-resistant superalloy comprising a substrate 3 (FIG 2), applying a high temperature resistant Superle ^¬ Government containing building material (FIG 2) on the substrate 3 (FIG 2) , Several individual Laserstrahlquel ^¬ len 1 (FIG 2) are arranged into the annular symmetrical laser beams 2, which at at least one point in the direction of the applied building material 8 laser beam 2 are grouped, so that a circular machining ^¬ zone 4 gives a molten bath. The laser beam sources 1 have in the direction of the applied build material 8 facing laser beams 2, wherein the laser beam sources 1 are arranged so as to give each other coaxial laser beams 2. The energy beams may overlap. Of course, the laser beams 2 can not overlap. Low-cost laser Radiation sources 1 (FIG 2) with a maximum laser power of 50-100 W.

According to the invention, each individual laser steel source 1 (FIG. 2) and thus each laser power can be controlled separately, so that lo ^¬ cal influence on the intensity distribution at the interaction zone laser radiation / applied build material 8 (FIG. 2) can be influenced. Due to the annular arrangement of the individual laser beams 2, a direction-independent material processing is made possible. A pendulum strategy of the total machining zone is made possible by the individual control of the laser beam sources 1 (FIG. 2); Thus, a la ^¬ terale movement of the machine tool is unnecessary. In general, the laser beam deposition welding by the control of the individual laser beam sources, a local heat treatment, in particular a preheating and / or reheating possible. This can for example be better

Create structural properties.

2 shows a cross section through an arrangement according to the invention. On a substrate 3 with a substrate surface 5, the turbine blades in a nickel or cobalt-based superalloy with high Y ^x content and therefore generally represents a difficult to weld alloy, material 8 is carried ^¬ .

A weld bead 6 as part of the build-up weld has already been produced.

In the case of a remelting process, the welding bead represents the remelted area.

The material 8 is supplied in the form of powder, but can also be supplied as a wire. The laser beams 2 are in particular pulsed. Preferably, a powder nozzle 14 with egg ^¬ ner powder nozzle feeder 10 as a material supply leads to powder 8, wherein the powder 8 is melted.

Where the laser beams 2 are directed to the substrate 3, a molten bath 7 is present. The laser beams 2 are arranged symmetrically annular. The laser beams 2 can be generated, for example, by means of a laser beam source 1 and deflecting mirrors 9. Low-cost laser beam sources with a maximum laser power of 50-100 W are used. In addition, the beams 2 are coupled coaxially through the powder nozzle 14 into the molten bath 7. The ^{advantages of} this arrangement are that each individual laser ^beam source 1 can be driven separately. The surface to be welded is built up from several side by side and optionally superimposed weld beads.

A pendulum strategy of the overall processing zone is made possible ^¬ light by the individual control of the laser beam sources, whereby a lateral movement of the machine tool is unnecessary.

In addition, improved material properties are achieved by this approach because of the OF INVENTION ^¬ dung. Although the invention has been illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples ^¬ limits. Variations thereof may be derived by those skilled in the art without departing from the scope of the invention as defined by the appended claims.

Claims

claims

1. Arrangement for the layered creation of a

Coating layer of highly heat-resistant superalloy comprising a substrate (3), wherein a highly heat-resistant superalloy containing building material (8) on the substrate (3) is placed ^¬ introduced,

d a d u r c h e s e n c i n e s, d a s s

for the partial production of a molten bath (7) in the applied building material (8) a plurality of individual in the direction of the applied building material (8) facing energy sources are arranged annularly symmetrical about at least one pointing in the direction of the applied building material energy source, all energy sources are separately controlled.

2. Arrangement according to claim 1,

d a d u r c h e s e n c i n e s, d a s s

the energy sources in the direction of the applied building material (8) have pointing energy beams, the energy beams are coaxial with each other.

3. Arrangement according to claim 1 or 2,

d a d u r c h e s e n c i n e s, d a s s

the energy sources are laser beam sources (1).

4. Arrangement according to claim 3,

d a d u r c h e s e n c i n e s, d a s s

the laser beam sources (1) a maximum laser power of

50-100 W have.

5. Arrangement according to one of the preceding claims, d a d u r c h e c e n e c e n e, d a s s

a control for controlling the energy sources and / or for modulating the power of the individual energy sources is provided.

6. Arrangement according to one of the preceding claims, characterized in that comprise energy sources in the direction of the applied building material facing (8) energy rays having a Ausbreitungsmit ^¬ center axis and a diameter, and wherein the

Diameter is changeable.

7. Arrangement according to one of the preceding claims, d a d u r c h e c e n e c e n e, d a s s

the energy sources in the direction of the applied build-up material (8) comprise energy beams pointing with a propagation center axis and also a material supply is provided, and wherein the material ^supply is arranged coaxially to the propagation ^central axis.

8. Arrangement according to claim 7,

d a d u r c h e s e n c i n e s, d a s s

the energy beams are coaxial feasible by the supply of material.

9. Arrangement according to claim 7 or 8,

d a d u r c h e s e n c i n e s, d a s s

the material supply is a powder nozzle (14).

10. Arrangement according to one of the preceding claims, d a d u r c h e c e n e c e n e, d a s s

the energy sources in the direction of the applied building material (8) comprise facing energy beams and at least partially overlap the energy beams at least on the applied building material (8).

11. Arrangement according to one of the preceding claims 1-9, d a d u r c h e c e n e c i n e t, d a s s

the energy sources in the direction of the applied building material (8) comprise energy rays pointing and the energy beams on the applied building material (8) do not overlap.

12. Arrangement according to one or more of the preceding claims, characterized in that

nickel- or cobalt-based superalloys can be used as the substrate (3).

13. Arrangement according to one or more of the preceding claims,

d a d u r c h e s e n c i n e s, d a s s

the energy sources are arranged uniformly annularly symmetrical about at least one energy source pointing in the direction of the applied build-up material.

14. Arrangement according to one or more of the preceding claims,

d a d u r c h e s e n c i n e s, d a s s

energy sources symmetrical about at least one facing in the direction of the applied building material energy source are arranged in a ring and wherein the ring symmet ^¬ driven by at least one facing in the direction of the applied building material energy source arranged energy sources has at least one uniform distance therefrom a source of energy.

15. Method for layering a

Coating layer of highly heat-resistant superalloy on a substrate (3), in which a highly heat-resistant superalloy containing building material (8) on the substrate (3) positioned ^¬ is introduced,

d a d u r c h e s e n c i n e s, d a s s

a plurality of individual, in the direction of the applied construction ^¬ material (8) facing annularly symmetrically arranged around at least one in the direction of the applied building material energy source energy sources a molten bath (7) in the applied building material (8) is generated in sections, all energy sources be controlled separately, so that there is a circular processing zone for the molten bath (7).

16. The method according to claim 15,

d a d u r c h e s e n c i n e s, d a s s

the energy sources in the direction of the applied building material (8) have pointing energy beams, wherein the energy sources are arranged so as to give each other coaxial energy beams.

17. The method according to claim 15 or 16,

d a d u r c h e s e n c i n e s, d a s s

a remelting takes place.

18. The method according to claim 15 or 16,

d a d u r c h e s e n c i n e s, d a s s

an overlay welding takes place.

19. Method for layering a

A coating layer according to any one of claims 15-18

d a d u r c h e s e n c i n e s, d a s s

by a separate control of the individual energy sources, a local heat treatment, in particular a preheating and / or a reheating of the applied building material (8) is made possible.

20. Method for layering a

A coating layer according to any one of claims 15-19,

d a d u r c h e s e n c i n e s, d a s s

is affected locally the intensity distribution by means of a separate control of the individual energy sources and in the direction of the applied building material facing (8) of energy beams at the interaction zone of the energy beam with the set ^¬ brought building material (8).

21. The method according to any one of the preceding claims 15-20, wherein the substrate (3) is a gas turbine blade and wherein the applied building material (8) is applied to a tip of the gas turbine blade or on a side surface of a Schau ^¬ felplattform the gas turbine blade.