EP3242765A1

EP3242765A1 - Shaft element, method for producing a shaft element composed of two different materials, and corresponding turbomachine

Info

Publication number: EP3242765A1
Application number: EP16710163.3A
Authority: EP
Inventors: Torsten-Ulf Kern; Stefan Brussk; Karsten Niepold
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2015-03-23
Filing date: 2016-03-16
Publication date: 2017-11-15
Also published as: WO2016150782A1; KR20170129845A; RU2017134831A; JP2018515707A; RU2689294C2; RU2017134831A3; EP3072624A1; CN107427949A; US20180073550A1

Abstract

The invention relates to a shaft element (1) of a turbomachine (2), in particular of a combined steam turbine (4), comprising at least two shaft subsegments (15, 16) integrally joined to each other by means of a weld (23), wherein different chemical and mechanical properties are inherent to said shaft subsegments (15, 16), wherein the weld (23) has a ratio of welding layer height to weld width of 1:14 to 1:2. The invention further relates to a method for producing a shaft element (1) composed of two different materials.

Description

description

WAVE ELEMENT, METHOD FOR PRODUCING A WAVEEL COMPONENT COMPOSED OF TWO DIFFERENT MATERIALS, AND CORRESPONDING FLOW MACHINE

The invention relates to a shaft element of a flow ^¬ machine, in particular a combined steam turbine, with at least two by means of a weld material together ^¬ conclusively joined shaft sections, in which these shaft sections inherent different chemical and mechanical properties.

The invention relates to a method for producing a composite of two different materials wave element, wherein two of different materials existing wave segments together by means of a weld cohesively to the shaft element together ^{¬ be} added.

The invention also relates to a turbomachine, in particular ^¬ sondere a combined steam turbine, with a a Axi ^¬ alachse rotating shaft member having two Wellenteilab ^¬ sections made of different materials which are connected by a weld material engagement with each other.

Generic shaft elements carry in turbomachines concentrically arranged around an axis of rotation axis run ^¬ blades or formed therefrom blade rings. Here, a plurality of rotor acting ^¬ felreihen may be arranged one behind the other on such shaft member.

Such a shaft element may extend axially through different ^¬ Liche portions of the flow machine and be exposed ^¬ here with different thermal and mechanical influences. Am example of a combined steam turbine, which, for example ^¬ adhesive comprises a medium-pressure turbine part and a nachge this ^¬ switched low pressure turbine section, the structure of the shaft member is to be explained in more detail.

Typically, this shaft member extends axially through both the mid-pressure turbine section and the low-pressure turbine section of the combined steam turbine. Beispiels- example, the shaft member extends with a first Wel ^¬ lenteilabschnitt in the intermediate-pressure turbine part and a further shaft section in the low pressure turbine portion.

Both a higher working pressure and a higher working temperature of the working medium prevail in the medium-pressure turbine part with regard to a working medium flowing through the combined steam turbine than is the case in the low-pressure turbine part of the combined steam turbine. For example, the working temperature of the working medium in the region of the medium-pressure turbine part is more than 400 ° C.

In this respect, the first shaft section of the shaft ^¬ elements in this medium-pressure turbine section is charged thermally higher when it interacts there with the working fluid.

Although the further shaft section of the shaft element in the downstream low-pressure turbine part is less thermally stressed, it is subjected to greater mechanical load.

In this respect, it is desirable if the differently loaded shaft sections of the shaft element have correspondingly adapted material properties. It is favorable when the first shaft part section in the area of the Be ^¬ intermediate-pressure turbine part consists of a more heat-resistant material, whereas the further shaft Part should be formed in the low-pressure turbine part of a rather cold ^¬ tough material.

Specifically on a turbomachine, such as just such a combined steam turbine with a medium-pressure turbine part and with a low-pressure turbine part adjoining thereto, an optimal property ^profile with respect to a shaft element at least partially extending in the axial direction through the turbomachine and produced in monoblock construction can not always be realized. This is mainly because the desired material properties are combined in the monobloc construction, which, however, disadvantageous compromises must be gone ^¬ which bind the optimal operation of the turbomachine or the combined steam turbine under ^¬.

Therefore, such elements by means of a shaft geeig ^¬ Neten welding process are often thermally assembled from a plurality of borrowed equipped with different properties shaft segments.

Such shaft joint welding provides a viable alternative for thermally joining together materials with different chemical compositions and with different mechanical properties, in particular "heat-resistant" and "cold-tough".

In this case, however, the problem often arises that the different material properties of these wave segments require a special welded construction with a buffer weld, by means of which, for example, a heat-resistant shaft segment of a later first Wellenteilabab ^{¬ section of} the shaft member with a cold-tough shaft segment of a later further wave section of Wellenele ^¬ can be welded. Here, the Pufferschwei- is preferably applied to the high heat resistant material of warmfes ^¬ th wave segment Ssung. For example, a procedure with a buffer weld from US 4,962,586 is known. Such a procedure also works so well to provide a shaft element, such as a combined steam turbine, with different shaft sections having inherent different properties. However, it also appears to be time-consuming and thus expensive.

In order to avoid the disadvantages with regard to such additional buffer welding, another method is disclosed in WO 2004/051056 AI, in which dispenses with such a buffer welding by a ge ^¬ targeted choice of materials with respect to the thermally to be joined together wave segments and an adapted heat treatment ^¬ can be .

It is an object of the invention to further develop generic shaft elements which are intended for use on a turbomachine, as well as, in particular, related manufacturing processes known for avoiding buffer welding.

The object of the present invention is a shaft element of a turbomachine, in particular a kombi ^¬ ned steam turbine, with at least two by means of a

Weld seam together wel ^¬ lenteilabschnitten cohesively joined together, in which these shaft sections different chemical and mechanical Eigen ^¬ properties inherent, the weld has a Schweißlagenhehen- to weld seam width ratio of 1:14 to 1: 2 up.

In particular, the present invention relates to an inert gas controlled inert gas arc in a narrow gap on steep flanks with targeted material property influencing in the actual welded joint or weld seam. The shaft member of a turbo machine is ^¬ portion as often thermally and mechanically loaded differently, be it in a compressor area or in a turbine area of the flow machine. In particular, a shaft element of a combined steam turbine is affected when a high-pressure turbine part, a medium-pressure turbine part and / or a low-pressure turbine part have a continuous shaft element, which is flowed around by a working medium flowing through the combined steam turbine.

Such combined steam turbines have a Einströ ^¬ mungsbereich and two or more formed with blades and vanes, successively connected turbine parts.

Here, for example, the first shaft portion of the shaft member in the high-pressure turbine section or the Mitteldruckturbinenteils thermally loaded higher than about the other shaft section of the shaft member in the low pressure turbine section, etc.

For this reason, it is advantageous for For make this first wave ^¬ part in sections using a hot firmer material ^¬.

By contrast, the further shaft section of the Wel ^¬ lenelements subject in the area of the low pressure turbine portion of a hö ^¬ heren mechanical load than the first shaft section of the shaft element in the region of the high-pressure or medium-pressure turbine part.

In this respect, it is advantageous if the further Wellenteilab ^{¬ section is} made of a cold-strength material. The same applies with regard to the shaft sections of the intermediate pressure turbine portion of the combined steam turbine in Be ^¬ train to the low pressure turbine portion of the combined steam turbine.

In any case, in the present case, the weld joint of shaft sections of different materials can be designed much better than before.

The object of the invention is thus also achieved by a method for producing a shaft element composed of two different materials, wherein wel ^¬ chem two wellen of different materials Wel- lensegmente be joined together by means of a weld cohesively mitein ^¬ other to the shaft element, wherein the weld is produced with a weld height / weld width ratio of 1:14 to 1: 2. The invention is characterized in that the first of the at least two shaft sections of a heat-resistant material lCrMoV; 2CrMoNiWV; 1 OCrMoWVNbN; lOCrMoVNbN or 9CrMoCoBNbN or 9Cr3CoWNbBN. The present invention particularly relates to a producible ^{information model} of a corresponding shaft member with the aid of a protective atmosphere in a teilmartensitischen range of 70% to 80% martensite transformation mix for the cohesive joining of two materials with different chemical and / or mechanical properties while avoiding the use of a buffer weld ,

It is understood that the welded connection in the present narrow gap between the shaft segments which are to be joined together materially to the shaft element can be further developed in particular by the following features. Thus, especially in the present narrow gap welding process, by means of a further development of the process control, monitoring and control, a targeted control of the welded joint or weld seam with regard to the adjustment of properties in the materials to be fused together, in the heat affected zone of the welding flanks and / or or in the weld itself possible.

The shaft element can be designed manifold. For example, the shaft element is ausgestal ^¬ tet as a rotor part.

A further embodiment variant provides, for example, that the weld seam comprises a plurality of weld layers, each of which is produced by a single weld bead, in order to achieve, via the set geometry of the respective weld bead, a weld layer compensation, in particular an intermediate layer compensation, of the respectively underlying weld layer. This also makes it possible to significantly improve the welded joint or weld produced between two different materials. Alone through this structure of

Welding the weld, a generic wave ^¬ element can be further developed advantageous, so that this feature is advantageous without the other features of the invention.

To this extent, a method for producing a corresponding shaft element corresponding to thereby develop who the that the welding positions of the weld seam is produced by only a single weld bead ^¬ to achieve a welding position compensation on the set geometry of the respective bead, in particular an intermediate layer fee, the welding layer underlying each , As already indicated above, the weld will be formed in a narrow gap ^¬ vorzugt, whereby the easily it can be generated ^¬ welding ^¬ were in each case by a single weld bead. Both the present Schweißlagenhöhen- / Schweißnahtbreiten- ratio and regardless of the structure of the welding ^{¬ in} terms of the number of required Schweißrau- pen can be achieved structurally and procedurally well, especially in the narrow gap.

For that reason alone, a further advantageous execution ^¬ variant provides that the weld comprises two joint edges axially countertransference lying steep, which each have a vertical of <1 °, which in relation ^¬ an opening angle of <1.5 °, preferably to To control a depth effect of an introduced heat energy particularly well. Here ^¬ by a local material influence in the respective gen edge areas can be particularly advantageously achieved.

In addition, it was found that an excellent

Welded joint or weld in connection with selected materials can be achieved.

The quality of the weld or to be formed of the weld seam can further be significantly improved if the other of the at least two shaft portions from egg ^¬ nem cryogenic material 2, 0-4, ONiCrMoV; 2, 0-4, ONiCrMoV Super Clean or 2CrNiMo is made.

In particular, the method on which the invention is based can be advantageously formed if a shaft segment is preheated to a preheating temperature between 100 ° C. and 350 ° C., preferably between 150 ° C. and 300 ° C., at least in one region of a welding flank prior to welding to improve heat flow distribution. This allows specifically a reduction of the Ansprunghärte in both Werkstof ^¬ fen the cohesively joined together Wellenseg- elements can be achieved.

Further, it is also advantageous regardless of the other features of the invention, when the weld, in particular the individual weld beads of the weld layers, by means of a

Welding speed of 30 mm / min to 450 mm / min, preferably ^¬ from 40 mm / min to 350 mm / min, is generated. Insbeson ^¬ particular, the above-mentioned heat-resistant and cold-resistant tool materials can thereby be particularly advantageously combined.

Cumulatively or alternatively, it is particularly expedient if the weld, in particular the individual weld beads of the welds, by means of a track energy of 5 kJ / cm to 30 kJ / cm is generated, since alone thereby independent of the other features of the invention positively to the two different welds connecting weld can be ^¬ acts.

On the welded joint or the weld can be further favorably acted when the weld, in particular the individual weld beads of the welding layers, a local heat treatment is subjected. In this case, the difference in different quality heat after-treatments of the materials to be joined plays a negligible role for the properties of the present weld with an additional application of a temperature of up to 20K below the tempering temperature of the higher alloyed base material, during a targeted property setting.

Through the invention described here is a manufacturing process with respect to a shaft member particularly well ^¬ it enables that adjusts by inert gas shielded with targeted control in compliance with defined parameters, the properties in the weld joint of a heat-resistant and of a cryogenic material without buffer weld.

To that extent in the execution of a Wellenschweißverbin- can dung from a heat resistant material on the one hand and a cryogenic material on the other hand omitted for different material combinations ^¬ in such a buffer weld. The object of the invention is also achieved by a flow ^¬ machine, in particular combined steam turbine, with a rotating around an axial axis shaft element having two shaft sections of different materials, which are connected by a weld cohesively mitein ^¬ other, the turbomachine by a Shaft element according to one of the features described herein and / or wherein the shaft member is made by a method according to one of the features described herein.

An equipped by the present wave element Strö ^¬ tion machine can be produced more cheaply.

Further features, effects and advantages of the present invention will be explained with reference to the appended drawing and the following description, in which an exemplary embodied in the context of the invention wave element of an exemplary Strömungsmaschine is shown and described.

In the drawing show:

Figure 1 shows schematically a partial view of a shaft member of a steam turbine in a transition region between a Mitteldruckturbinenteil and Nie ^¬ derdruckturbinenteil with two made of different materials Wellenteilabschnitten which are joined together by a weld material fit together; and

Figure 2 schematically shows the weld joint in an edge region of a first wave segment of a warm ^¬ solid material and another wave segment of a cold-tough material of the shaft element shown in Figure 1, wherein the first wave ^¬ segment the shaft section on the medium-pressure ^¬ turbine part and the other wave segment the world Lenteilabschnitt forms at the low-pressure turbine part.

The shaft member 1 shown in Figure 1 is used (not shown) of the on ^¬ acquisition a plurality of blades and it is so installed that it rotates about a Axialrotationsachse 3 during operation of the turbomachine 2 in a not shown in detail Strömungsma ^¬ machine. 2

In this embodiment, it is in the Strö ^¬ mung machine 2 by a not shown in detail combined steam turbine 4, which extends through a Mitteldruckturbinen- part (not shown) (not shown) is distinguished and a downstream subsequent low-pressure turbine part.

The shaft element 1 extends in the axial direction 5 ent ^¬ long the Axialrotationsachse 3 of an input portion 6 of the combined steam turbine 4 through a Mitteldruck- area 7 of the combined steam turbine 4 on a

Low pressure range 8 of the combined steam turbine 4 to an output range 10 of the combined steam turbine. 4

In this case, a first shaft section 15 is located substantially in the medium-pressure region 7 and a further shaft section 16 is arranged substantially in the low-pressure region 8, so that these shaft sections 15 and 16 with a combined steam turbine 4 from the input ^¬ area 6 to the Output area 10 flowing through working medium, mainly superheated steam, interact.

In this case, the working medium in the medium-pressure region 7 in particular still has a higher operating temperature than in Nie ^¬ derdruckbereich 8, so that the first shaft portion 15 is thermally loaded higher than the other Wellenteilab ^{¬ section} 16 of the shaft member. 1 However, the other shaft member portion 16 mechanically hö ^¬ forth is loaded as the first shaft member portion 15 of the Wel ^¬ lenelements 1. This implies that the first shaft portion 15 of the shaft ^¬ elements 1 made of a heat-resistant material (not separately numbered) is to be produced as the more Wellenab ^{¬ section} 16 of the shaft element 1. The heat-resistant material used here is lCrMoV.

Alternatively it can be replaced by another of the heat-resistant materials 2CrMoNiWV, lOCrMoWVNbN, lOCrMoVNbN or 9CrMoCoBNbN or 9Cr3Co3WNbBN.

Consequently, the further shaft portion 16 of the Wellenele ^¬ element 1 of a cold-strength material (not separately be ^¬ ziffert) to be made as the first shaft portion 15 of the shaft member. 1

The cold-tough material used here is 2.0 NiCrMoV.

Alternatively, it can be replaced with another of the cold-tough materials 2, 0-4, ONiCrMoV, 2, 0-4, ONiCrMoV Super Clean or 2CrNiMo.

In any case, the shaft member 1 of a first wave ^¬ segment 20 (heat-resistant material) and another wave segment 21 (cold-tough material) composed, the two different wave segments by means of a

Welded joint 22 thermally joined, that is, materially joined together, are.

FIG. 2 shows the structure of a weld seam 23 of FIG

Welded connection 22 schematically and partially on the basis of an edge region cutout 24 of the shaft element 1. The weld 22 or the weld 23 is a narrow gap 25 between the first shaft segment 20 and the white ^¬ direct wave segment 21 basis, which axially face each other and designing ^¬ a weld joint 26th

At the weld joint 26 there are two joint flanks 29 and 30, which are formed by the wave segments 20 and 21, each of the joint flanks 29 and 30 having only an opening angle 32 of <1 ° (only exemplarily numbered) relative to the vertical 31. As a result, the effects of undesired heat input into the adjacent material ^regions can be reduced. The opening angle 32 and thus the employment of the joint flanks or the welding flanks 29 and 30 are here shown exaggerated.

At the thus prepared weld joint 26, the weld seam 23 formed in the sense of the invention can now be further advantageously formed. The weld 23 is characterized in particular by a

Schweißlagenhöhen- / Schweißnahtbreiten ratio 35 from 1:14 to 1: 2, wherein in the present case the weld ^levels 36 by the thickness 37 of a single weld bead 38 and the weld seam ^¬ width 39 by the width 40 of the respective individual weld bead 38 is formulated.

The Schweißlagenhöhen- / weld seam width ratio 35 is in this embodiment also dependent on the changing in the direction of the vertical 31 joint width.

Here, the thickness 37 of the weld layer height 36 is aligned in the direction of the vertical 31 and the width 40 of the weld ^¬ width 39 extends transversely to this vertical 31. Another particularity of the present weld 22 and the weld 23 results from the fact that each of the weld layers 41 only a single bead 38 has. As a result, it is particularly easy to influence the welding layer compensation.

Each of the weld beads 38 is here, for example at a welding speed of 100 mm / min at a Streckenener ^¬ energy of 15 kJ / cm was generated.

In this case, the welding flanks 29 and 30 have previously been preheated by way of example to a preheating temperature of 200 ° C. in order to achieve an improved heat flux distribution.

Although the invention has been further illustrated and described in detail by the preferred embodiment, the invention is not limited by this disclosed Ausführungsbei- game, and other variations can be derived from the ^{expert ¬} man from this, without departing from the scope of the invention.

Claims

claims

1. shaft element (1) of a turbomachine (2),

in particular a combined steam turbine (4),

with at least two means of a weld (23) mitein ^¬ other cohesively joined together shaft sections (15, 16), wherein these shaft sections (15, 16) inherent to different chemical and mechanical properties,

wherein the weld seam (23) has a weld height / weld seam width ratio of 1:14 to 1: 2,

wherein the first of the at least two shaft sections (15, 16) made of a heat-resistant material lCrMoV; 2CrMoV, 2CrMoNiWV; 1 OCrMoWVNbN; lOCrMoVNbN; 9CrMoCoBNbN or

9Cr3Co3WNbBN is made.

2. shaft element (1) according to claim 1,

wherein the weld (23) a plurality of weld layers (41) includes fully, which is generated in each case by a single weld bead (38) over the selected geometry of the jewei ^¬ time weld bead (38) is a welding pass compensation, in particular an intermediate layer fee, each including lying welding position (41) to achieve.

3. shaft element (1) according to claim 1 or 2,

wherein the weld seam (23) has two axially gegenüberlie ^¬ constricting, steep joint edges (29, 30), each relative to a vertical (31) an opening angle (32) of <1.5 °, preferably <1 °, having, to control a Tie ^¬ fen effect of an introduced heat energy particularly well.

4. shaft element (1) according to one of claims 1 to 3, wherein the further of the at least two shaft sections (15, 16) made of a cold-tough material 2, 0-4, ONiCrMoV; 2,0- 4,0NiCrMoV Super Clean or 2CrNiMo is made.

5. shaft element (1) according to one of claims 1 to 3, wherein the further of the at least two shaft sections (15, 16) made of a low-alloy, heat-resistant material lCrMoV; 2CrMoV; or 2CrMoNiWV and the second material of type 1 OCrMoWVNbN; 10CrMoVNbN;

9CrMoCoBNbN or 9Cr3Co3WNbBN is.

Method for producing a shaft element (1) composed of two different materials,

in particular, the shaft member (1) according to one of the standing before ^¬ claims,

in which two shaft segments (20, 21) made of different materials are joined together in a material-locking manner to the shaft element (1) by means of a weld seam (23),

wherein the weld seam (23) is produced with a weld ply height to weld width ratio (35) of 1:14 to 1: 2,

wherein the first of the at least two shaft sections (15, 16) made of a heat-resistant material lCrMoV; 2CrMoV, 2CrMoNiWV; 1 OCrMoWVNbN; 10CrMoVNbN; 9CrMoCoBNbN or

9Cr3Co3WNbBN is made. 7. The method according to claim 6,

wherein welding layers (41) of the weld seam (23) by only ^¬ single weld bead (38) is generated to the set geometry of the respective weld bead (38) a Schweißlagenvergütung, in particular an intermediate layer compensation, the underlying each welding position

(41). Method according to claim 6 or 7,

wherein a shaft segment (20, 21) is preheated to a preheating temperature between 100 ° C and 350 ° C, preferably between 150 ° C and 300 ° C, at least in a region of a welding flank (29, 30) prior to welding, to generate heat ^¬ flow distribution to improve.

Method according to one of claims 6 to 7,

wherein the weld (23), in particular the individual weld beads (38) of the weld layers (41), by means of a welding speed of 30 mm / min to 450 mm / min, preferably ^¬ before 40 mm / min to 350 mm / min, is generated ,

Method according to one of claims 6 to 9,

wherein the weld seam (23), in particular the individual weld beads (38) of the weld layers (41), is produced by means of a line energy of 5 kJ / cm to 30 kJ / cm.

Method according to one of claims 6 to 10,

wherein the weld (23), in particular the individual weld beads (38) of the weld layers (41), is subjected to a local heat treatment.

Turbomachine (2),

in particular combined steam turbine (4),

rotating a to a axial axis (3) shaft element (1) comprising two shaft sections (15, 16) of which under ^¬ different union materials which by a weld seam (23) are bonded to each other, wherein the turbomachine (2) extending through a Wellenele ^¬ ment (1) according to one of claims 1 to 5 and / or

wherein the shaft member (1) is made by a method according to any one of claims 6 to 11.