JP2003172150A - Softening heat treatment method for gas turbine blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a softening heat treatment method for a gas turbine blade capable of performing softening heat treatment in a short time by using a simple heat treatment means when the softening heat treatment is performed for a blade. <P>SOLUTION: The blade 1 for heat treatment and a dummy blade 2 are assembled so that distal ends may be closely contacted with each other. A heating coil C is arranged to be close to the blades 1 and 2. The heating coil C is connected to a high frequency inverter 3 as a power source device for high frequency induction heating. High frequency current is supplied from the high frequency inverter 3 to the heating coil C to heat a region including the distal end of the blade 1 up to a solution treatment temperature. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a softening heat treatment method for a gas turbine blade, in which a gas turbine blade whose material has been hardened for a long period of time is subjected to a softening heat treatment using a simple heat treatment means.

[0002]

2. Description of the Related Art The maintenance of gas turbines for electric power generation has become more important as the capacity and temperature of gas turbines have increased. In particular, the gas turbine blades that have been in operation for a long time as the gas turbine inlet temperature rises are prone to quality deterioration such as material hardening, deformation, damage, and abrasion, and careful planned maintenance is essential. .

By the way, in maintenance of a gas turbine blade, it is too wasteful to replace an expensive moving blade with a new moving blade for a short period of time. Or, it is desired to repair a moving blade whose material is deteriorated and to use it again. When a blade that requires such repair is removed from the rotor and then immediately repaired, the material exposed to the high temperature gas for a long time often has hardened material, and It causes cracks and other problems.

[0004] Before starting repair in anticipation of the occurrence of such a defect, the moving blade is subjected to a softening heat treatment in advance so as to be easily processed. In this softening heat treatment, it is necessary to heat the entire moving blade to a temperature close to where recrystallization of the material occurs, and conventionally, for example, a vacuum furnace 21 as shown in FIG. 11 has been used. Here, the moving blades 22 are arranged side by side on the parts table 23, and a method of carrying them together with the parts table 23 into the vacuum furnace 21 is used.

[0005]

In the method of loading the moving blades 22 to be treated into the vacuum furnace 21 and heating them, it takes a certain amount of time to heat all the moving blades 22 to a desired target temperature. However, there is a drawback that a great amount of time must be spent until the heat treatment is completed.

On the other hand, in many cases, such a rotor blade 22 is
For example, since the final solution heat treatment and aging heat treatment must be carried out after repairing minor damage, it is preferable that this softening heat treatment performed before repair is performed without waste of time and effort and without waste. However, no method has been found for performing such softening heat treatment without spending a great deal of time.

Therefore, an object of the present invention is to provide a softening heat treatment method for a gas turbine blade, which enables the softening heat treatment to be performed in a short time by using a simple heat treatment means when performing the softening heat treatment on the blade. It is in.

[0008]

In the softening heat treatment method for a gas turbine blade according to the present invention, when the softening heat treatment is applied to the region including the tip of the blade, the region including the tip of the blade is locally melted by a high frequency induction heating operation. It is heated to the reaction temperature.

In such a softening heat treatment method, when the softening heat treatment is applied to the gas turbine blade, it is heated to a desired heat treatment temperature in a very short time using a simple device without using a large-sized device. It will be possible
A softening heat treatment can be performed.

In the method of the present invention, it is desirable that a blade and a dummy blade are prepared, the tip of the dummy blade is brought into contact with the tip of the blade, and the tip is heated to a predetermined temperature by high-frequency induction heating operation.

According to such a heat treatment method, the region including the tip of the blade can be softened without carrying it into a vacuum furnace for batch processing. Further, since the dummy blade is brought into contact with the tip of the blade, it is possible to prevent the vicinity of the edge from falling into an overheated state, which is likely to occur when the high frequency output is increased.

In the method of the present invention, a first blade and a second blade are prepared, and the tip of the first blade is brought into contact with the tip of the second blade.
You may heat to a predetermined temperature by a high frequency induction heating operation.

According to such a heat treatment method, since the tips of the first blade and the second blade are brought into contact with each other, the two turbine blades can be softened by one heating operation.
Furthermore, since the tips of the blades are brought into contact with each other, it is possible to prevent the vicinity of the edge from falling into an overheated state.

In the method of the present invention, the region including the tip of the blade may be heated under an inert gas atmosphere.

According to such a heat treatment method, only the heat treatment target portion of the work can be placed in the inert gas atmosphere, and the region including the blade tip can be prevented from oxidizing with a small gas consumption amount. it can.

According to the method of the present invention, when there is a temperature difference between the region including the blade tip and the dummy blade, the high frequency induction heating coil is moved from the high temperature side blade to the low temperature side blade for heating. Good.

According to such a heat treatment method, even when the member contact surface between the blade and the dummy blade is distorted and the thermal equilibrium cannot be easily maintained, the high frequency induction heating coil is moved freely. The thermal equilibrium between the members can be maintained within a short time, and the softening heat treatment can be performed at a desired temperature.

According to the method of the present invention, the blade and the dummy blade are prepared, and the tip of the dummy blade is brought into contact with the tip of the blade via the intermediate member and heated to a predetermined temperature by the high frequency induction heating operation. Good.

According to such a heat treatment method, since the intermediate member is made of a material that is well suited to the contact surfaces of the blade and the dummy blade, there is a gap in the member contact surface due to deformation or the like. It is also possible to bury it and maintain good contact with the respective abutting surfaces, which makes it possible to heat the region including the tip of the blade more uniformly.

According to the method of the present invention, at least three blades are prepared, the tips of the blades are brought into contact with each other, and the contacted portions of the respective blades can be heated individually or simultaneously by a high frequency induction heating operation. .

According to such a heat treatment method, at least three blades are brought into contact with each other for heat treatment, so that the treatment time can be greatly shortened when they are simultaneously heated. On the other hand, also in the case of individually heating, since the blade to be heat-treated next is preheated, the processing time can be shortened.

According to the method of the present invention, a blade and a dummy blade made of a material having a heat generation characteristic superior to that of the blade by a high frequency induction heating operation are prepared, and the tip of the dummy blade is brought into contact with the tip of the blade to perform high frequency induction heating. Can be heated to a predetermined temperature.

According to such a heat treatment method, since the material having excellent heat generation characteristics by the induction heating operation is used for the dummy blade, the time required for heating to the predetermined temperature can be shortened.

According to the method of the present invention, a diffusion barrier is formed at the tip of the dummy blade, and the tip of the dummy blade is brought into contact with the tip of the blade so that the tip surface of the blade and the diffusion barrier are in contact with each other and heated to a predetermined temperature. You may

According to such a heat treatment method, since the diffusion barrier is formed at the tip of the dummy blade, it is possible to prevent undesired components from diffusing into the structure of the blade during the heat treatment.

In the method of the present invention described above, a blade is prepared in which the implanting portion is fixed to the rotor disk and the chips are in contact with each other in the circumferential direction, and the region including the chips is heated to a predetermined temperature by a high frequency induction heating operation. May be.

According to such a heat treatment method, since the softening heat treatment is performed before the blade is disassembled from the rotor, it is not necessary to attach a dummy blade to each blade, and the preparatory work before the heat treatment can be omitted. The working time can be greatly reduced.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A first embodiment of the present invention will be described with reference to the drawings. The method of the present invention uses a high frequency induction heating coil to heat the workpiece. That is, in FIG. 1, a blade 1 to be heat-treated and a dummy blade 2 having a shape similar to that are prepared. The blade 1 and the dummy blade 2 are pre-assembled so that the tips are in close contact with each other, and then the heating coil C is sent from the dummy blade 2 side toward the member contact surface and arranged close to the blades 1 and 2. To be done. The dummy wing 2 is finished so that the contact surface contacting the wing 1 is preferably capable of maintaining the meshing. The heating coil C is connected to a power supply device for high frequency induction heating, for example, a high frequency inverter 3.

Next, the softening heat treatment method will be described. A high frequency current is supplied from the high frequency inverter 3 to the heating coil C. The blade 1 and the dummy blade 2 are heated by the high frequency current flowing in the heating coil C, and the temperature rises. further,
While adjusting the output of the high frequency inverter 3, the region including the tip of the blade 1 is heated to the target temperature. The state is maintained for a predetermined time while maintaining the target temperature. This heat treatment softens the region including the tip of the blade 1 hardened by the high temperature gas. After that, the output of the high frequency inverter 3 is stopped, and the dummy blade 2 is removed from the blade 1.

The target temperature in the above process is preferably the solution temperature of the blade 1. In the normal solution heat treatment, the target temperature is maintained and the state is maintained for several hours, but in the heat treatment method of the present embodiment, the solution is softened to the extent that cracks do not occur in the subsequent repair. Therefore, the holding time is set shorter than the normal holding time. This holding time varies depending on the blade material, but it is sufficient to take about several minutes to several tens of minutes.

In the present embodiment, the region including the tip of the blade 1 can be softened without carrying it into a vacuum furnace for batch processing. Furthermore, since the dummy blade 2 is brought into contact with the tip of the blade 1, it is possible to prevent the vicinity of the edge from falling into an overheated state, which is likely to occur when the high frequency output is increased. Further, due to a change in the output of the high-frequency inverter 3 that holds the target temperature, the vicinity of the edge is more likely to be overheated than other portions or the temperature is likely to drop in advance, but since the dummy blade 2 is brought into contact with the tip of the blade 1, Occurrence of such a problem can be suppressed.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIG. First blade 1 and second blade 4 to be heat treated are prepared. The first blade 1 and the second blade 4 are preassembled so that their tips are in close contact with each other, and then the heating coil C is on the side of the second blade 4 (may be on the side of the first blade 1 in some cases). Is sent toward the member abutting surface and is arranged close to the wings 1 and 4. The heating coil C is connected to the high frequency inverter 3.

Next, the softening heat treatment method will be described. A high frequency current is supplied from the high frequency inverter 3 to the heating coil C. The first and second blades 1 and 4 are heated by the high frequency current flowing in the heating coil C, and the temperature rises. Further, while adjusting the output of the high frequency inverter 3, the regions including the tips of the first and second blades 1 and 4 are heated to the target temperature. The state is maintained for a predetermined time while maintaining the target temperature. This heat treatment softens the regions including the tips of the first and second blades 1 and 4 hardened by the high temperature gas. After that, the output of the high frequency inverter 3 is stopped.

Also in this heat treatment method, the first and second
The blades 1 and 4 are softened to the extent that cracks do not occur. That is, the holding time is about several minutes to several tens of minutes.

In the present embodiment, since the tips of the first and second blades 1 and 4 are brought into contact with each other, the two turbine blades can be softened by one heating operation. Furthermore, since the tips of the first and second blades 1 and 4 are brought into contact with each other, it is possible to prevent the vicinity of the edge from falling into an overheated state. Further, since the second blade 2 is brought into contact with the tip of the first blade 1, it is possible to prevent the vicinity of the edge from overheating or lowering the temperature in advance than the other portions.

(Third Embodiment) A third embodiment of the present invention will be described with reference to FIG. It is the same as in the first embodiment that the blade 1 to be heat-treated and the dummy blade 2 are prepared and the heating coil C is arranged close to it. In the present embodiment, the thermocouple 5 for temperature measurement is arranged at the contact portion of both members. This thermocouple 5 has an extremely thin temperature measuring contact, and it is sandwiched between the tip of the wing 1 and the tip of the dummy wing 2, and the + leg and the − leg are pulled out from each, and the compensating lead wire is used. Connect to transducer and instrument (neither shown).

The heat treatment procedure of this embodiment is the same as that of the first embodiment. During this heat treatment, the temperature of the region including the tip of the blade 1 is measured by the thermocouple 5. Thereby, during the softening heat treatment, the temperature of the region including the tip of the blade 1 can be read by the measuring instrument and it can be confirmed that the temperature does not deviate from the target temperature.

Desirably, the temperature measuring contact is arranged apart from the heating coil C so as not to be influenced by the high frequency current.
This may be arranged in a hole drilled in the dummy blade 2 in order to maintain the measurement accuracy. Further, instead of the thermocouple 5 of the present embodiment, a non-contact type radiation thermometer may be used.

In the present embodiment, in particular, since the thermocouple 5 is arranged at the member contact portion at the tip of the blade 1, the blade 1
It is possible to more accurately measure the temperature of the region including the tip of the, and it is possible to prevent a measurement error from occurring in maintaining the target temperature of the heat treatment.

(Fourth Embodiment) A fourth embodiment of the present invention will be described with reference to FIG. A blade 1 to be heat-treated and a dummy blade 2 are prepared. The blade 1 and the dummy blade 2 are preassembled so that their tips are in close contact with each other. Further, the heating coil C is sent from the dummy blade 2 side toward the member contact surface and is arranged close to the blades 1 and 2.
The heating coil C is connected to the high frequency inverter 3.

In this embodiment, the shield box 6 surrounding the heat treatment target portion of the work is used. The shield box 6 has a seal portion formed at each of the contact points with the blade 1 and the dummy blade 2 in order to keep the heat treatment target portion in an inert gas atmosphere, and is configured so that ambient air does not flow into the inside. It This seal part is connected to a cooling device (not shown) through which cold water circulates. The shield box 6 is connected to an inert gas source, for example, a cylinder (not shown) filled with argon gas.

The heat treatment procedure of this embodiment is the same as that of the first embodiment. During this heat treatment, the heat treatment target portion of the work is placed under an argon gas atmosphere. This makes it possible to prevent the region including the tip of the blade 1 from being oxidized.

In the present embodiment, the shield box 6 allows only the heat treatment target portion of the work to be kept in the inert gas atmosphere, and the region including the tip of the blade 1 is prevented from oxidizing with a small gas consumption. It will be possible. In addition, since the relatively small shield box 6 that surrounds only the heat treatment target portion is used, the softening heat treatment can be performed without taking time and effort for setup.

(Fifth Embodiment) A fifth embodiment of the present invention will be described with reference to FIG. A blade 1 to be heat-treated and a dummy blade 2 are prepared. The blade 1 and the dummy blade 2 are preassembled so that their tips are in close contact with each other. Further, the heating coil C is sent from the dummy blade 2 side toward the member contact surface and is arranged close to the blades 1 and 2.
The heating coil C is connected to the high frequency inverter 3.

Further, in this embodiment, the guide mechanism 7 for guiding the heating coil C is provided. The heating coil C can move in the blade axis direction along the guide mechanism 7.

The heat treatment procedure of this embodiment is the same as that of the first embodiment. When a certain temperature difference occurs between the blade 1 and the dummy blade 2 during this heat treatment, the heating coil C is moved to the blade side having a lower temperature. That is, when the temperature of the region including the tip of the blade 1 is high, the heating coil C is moved in the direction of the dummy blade 2 along the guide mechanism 7, and when the temperature of the region including the tip of the dummy blade 2 is high, the blade 1 The heating coil C is moved along the guide mechanism 7 in the direction of. In this way, the blade 1 and the dummy blade 2 which are brought into contact with each other are heated so that thermal equilibrium is maintained.

In the present embodiment, blade 1 and dummy blade 2
Even when the member contact surface is deformed due to deformation or the like between them and the thermal equilibrium cannot be easily maintained, the thermal equilibrium between the members is quickly moved while freely moving the heating coil C. Can be held, and the softening heat treatment can be performed at a desired temperature.

(Sixth Embodiment) A sixth embodiment of the present invention will be described with reference to FIG. A blade 1 to be heat-treated and a dummy blade 2 are prepared, and in addition to this, an intermediate member 8 to be inserted between the two blades 1 and 2 is prepared. The blade 1 and the dummy blade 2 are preassembled such that the intermediate member 8 is sandwiched and the tips are in close contact with each other. This intermediate member 8
In particular, the contact surface is made of a fibrous material, a porous material, or the like that is well suited to the contact surfaces of the blades 1 and 2. Further, the heating coil C is sent from the dummy blade 2 side toward the member contact surface and is arranged close to the blades 1 and 2. The heating coil C is connected to the high frequency inverter 3.

On the other hand, a thermocouple 5 for temperature measurement is arranged inside the intermediate member 8. Then, from the temperature measuring contact, + leg and-
Each leg is withdrawn and connected to a transducer and instrument (both not shown) via compensating leads.

The heat treatment procedure of this embodiment is the same as that of the first embodiment. During this heat treatment, the temperature of the region including the tip of the blade 1 is measured by the thermocouple 5 incorporated in the intermediate member 8. The temperature of the region including the tip of the blade 1 is read by a measuring device and it is confirmed that the temperature does not deviate from the target temperature.

In the present embodiment, the intermediate member 8 is the blade 1
Also, since it is made of a material that is well-fitted to the contact surface of the dummy blade 2, even if there is a gap in the member contact surface due to deformation or the like, it is filled and good contact with each contact surface Can be held at. Thereby, the region including the tip of the blade 1 can be heated more uniformly, and the softening heat treatment can be performed at a desired temperature.

Further, it is not necessary to bring the temperature measuring means into contact with or sandwich the work itself by the thermocouple 5 in the intermediate member 8, and the softening heat treatment can be performed without troublesome setup.

(Seventh Embodiment) A seventh embodiment of the present invention will be described with reference to FIG. A dummy blade 2 having a shape similar to that of the blade 1 to be heat treated is prepared. This dummy blade 2 is assembled in advance with the heating coil to form an integrated heating coil 9. An electric insulation is completely maintained between the dummy blade 2 and the heating coil with an insulating material. In the softening heat treatment, the blade 1 and the dummy blade 2 in the integrated heating coil 9 are assembled so that their tips are in close contact with each other. Further, in the present embodiment, the integrated heating coil 9
A guide mechanism 7 for guiding the.

The heat treatment procedure of this embodiment is the same as that of the first embodiment. That is, a high frequency current is supplied from the high frequency inverter 3 to the heating coil of the integrated heating coil 9. The blade 1 and the dummy blade 2 are heated by the high-frequency current flowing in the heating coil, and the temperature rises. Further, while adjusting the output of the high frequency inverter 3, the region including the tip of the blade 1 is heated to the target temperature. The state is maintained for a predetermined time while maintaining the target temperature. As a result, the region including the tip of the blade 1 hardened by the high temperature gas is softened.

In this embodiment, since the heating coil and the dummy blade 2 are integrated, the heating coil can be arranged at an optimum position simply by bringing it into contact with the work.
It becomes possible to shorten the working time.

(Eighth Embodiment) An eighth embodiment of the present invention will be described with reference to FIG. First blade 1, second blade 4 and third blade 10 to be heat treated are prepared. The first wing 1 and the second wing 4 are preassembled so that their tips are in close contact with each other, and the second wing 4 and the third wing 4 are
And the blades 10 are assembled in advance so that the tips are in close contact with each other. Further, the first heating coil C1 and the second
Heating coil C2 is sent toward the member contact surface of each blade and is arranged close to blades 1, 4 and blades 4, 10. The heating coil C1 and the heating coil C2 are individually connected to the high frequency inverter 3.

Next, the softening heat treatment method will be described. A high frequency current is supplied from the high frequency inverter 3 to the heating coil C1. Similarly, a high frequency current is supplied from the high frequency inverter 3 to the heating coil C2. The first blade 1 and the second blade 4 are heated by the high frequency current flowing in the heating coil C1, and the temperature rises. Further, the second blade 4 and the third blade 10 are heated by the high frequency current flowing in the heating coil C2, and the temperature rises.

Further, while adjusting the output of the high frequency inverter 3, a region including the tips of the first and second blades 1 and 4 up to the target temperature, and the tips of the second and third blades 4 and 10 are included. Each area is heated. While maintaining the target temperature, the state is maintained for a predetermined time. This heat treatment softens the regions including the tips of the first and second blades 1 and 4 and the regions including the tips of the second and third blades 4 and 10 which are hardened by the high temperature gas.

In the above heat treatment method, four or more blades may be heat-treated at the same time. Alternatively, instead of performing the softening heat treatment on all the blades at the same time, the blades may be heated one by one. You may Further, the heating coil C1 and the heating coil C2 may be connected in series by using one high-frequency inverter having a higher output.

In the present embodiment, at least three blades 1, 4 and 10 are brought into contact with each other for heat treatment, so that the processing time can be greatly shortened when heating each blade simultaneously. On the other hand, even when the blades are individually heated, the processing time can be shortened because the blades to be heat treated next are preheated.

(Ninth Embodiment) A ninth embodiment of the present invention will be described with reference to FIG. A blade 1 to be heat-treated and a dummy blade 2 are prepared. This dummy wing 2
In particular, it is made of a material containing carbon or the like which is excellent in induction heating.
Further, a diffusion barrier 11 is formed at the tip of the dummy blade 2 that is in contact with the blade 1. The diffusion barrier 11 is intended to prevent components such as carbon contained in the dummy blade 2 from diffusing into the blade 1 during heat treatment, and is composed of, for example, a ceramic sprayed layer or a heat resistant alloy sprayed layer. As a result, wing 1
And the tip of the dummy blade 2 are in contact with each other via the diffusion barrier 11.

The heat treatment procedure of this embodiment is the same as that of the first embodiment. During the softening heat treatment, carbon contained in the dummy blades 2 heated to a high temperature tries to diffuse into the blades 1 in contact with the dummy blades 2, but is blocked by the diffusion barrier 11 of the dummy blades 2 and enters the blades 1. Does not spread.

In this embodiment, since the dummy blade 2 is made of a material having excellent heat generation characteristics due to the induction heating operation,
The time required for heating to a predetermined temperature can be shortened. Further, since the diffusion barrier 11 is formed at the tip of the dummy blade 2, the undesirable component during the heat treatment is the blade 1.
It is possible to prevent it from spreading to other tissues.

(Tenth Embodiment) A tenth embodiment of the present invention will be described with reference to FIG. The gas turbine blade is a moving blade 1 before it is removed from the rotor shaft.
Prepare 2. The blades of each rotor blade 12 are fixed to the entire circumference of the rotor disk 13 so that the blade tip, that is, the tip 1
4 are spliced in the circumferential direction so as to contact the front edge of the chip and the rear edge of the adjacent chip 14, and the rear edge of the chip and the front edge of the adjacent chip 14.

The heating coil C for softening heat treatment is arranged close to the outer peripheral area of the tip 14 of the moving blade 12.
During the softening heat treatment, the rotor itself rotates in the direction of the arrow shown in the drawing by a driving device (not shown). The moving blades 12 are sequentially sent to the heating coil C one by one by an indexing device (not shown) and heated. The heating coil C is connected to the high frequency inverter 3.

The heat treatment procedure of this embodiment is the same as that of the first embodiment. The softening heat treatment conditions are basically the same as those using the dummy blade. When the region including the tip 14 of the rotor blade 12 is similarly hardened, the heat treatment is carried out under the same conditions. However, when the degree of hardening is different, the heat treatment conditions are changed according to the measured hardness. You can change it. Also, the blade 1 which is not so hardened
Regarding No. 2, it may be excluded from the target of heat treatment.
In the present embodiment, the heating coil C may be mounted on, for example, a truck running on a guide rail, and the rotor blade 12 in a fixed state may be subjected to heat treatment.

In this embodiment, since the softening heat treatment is performed before the rotor blades 12 are disassembled from the rotor, the individual rotor blades 1
Since it is not necessary to attach dummy blades to 2, the preparatory work before heat treatment can be omitted, and the working time can be greatly shortened.

In the present invention, the following method can be used instead of the high frequency induction heating method. As a typical high energy beam, laser light is used to heat the area including the tip of the turbine blade. However, since the laser beam has a high energy density, the beam focus should be removed from the region including the tip of the blade to be heated. Since this method provides more localized heating than the induction heating operation, it is desirable to irradiate a relatively small blade or, when applied to a large blade, irradiate a small area to work efficiently.

Further, in the present invention, instead of the laser light, an electron beam may be used for the same heating.

[0070]

According to the present invention, when the softening heat treatment is applied to the gas turbine blade, it is heated to a desired heat treatment temperature in a very short time by using a simple device without using a large device. Therefore, the softening heat treatment can be performed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a heat treatment method according to the present invention.

FIG. 2 is a schematic configuration diagram showing a second embodiment of a heat treatment method according to the present invention.

FIG. 3 is a schematic configuration diagram showing a third embodiment of a heat treatment method according to the present invention.

FIG. 4 is a schematic configuration diagram showing a fourth embodiment of a heat treatment method according to the present invention.

FIG. 5 is a schematic configuration diagram showing a fifth embodiment of a heat treatment method according to the present invention.

FIG. 6 is a schematic configuration diagram showing a sixth embodiment of the heat treatment method according to the present invention.

FIG. 7 is a schematic configuration diagram showing a seventh embodiment of a heat treatment method according to the present invention.

FIG. 8 is a schematic configuration diagram showing an eighth embodiment of a heat treatment method according to the present invention.

FIG. 9 is a schematic configuration diagram showing a ninth embodiment of a heat treatment method according to the present invention.

FIG. 10 is a schematic configuration diagram showing a tenth embodiment of a heat treatment method according to the present invention.

FIG. 11 is a configuration diagram showing an example of a conventional softening heat treatment method for a gas turbine blade.

[Explanation of symbols]

1 ... Blade, 2 ... Dummy blade, 3 ... High frequency inverter, 4 ... Second blade, 5 ... Thermocouple, 6 ... Shield box, 7 ... Guide mechanism, 8 ... Intermediate member,
9 ... Integrated heating coil, 10 ... Third blade, 11
... diffusion barrier, 12 ... moving blade, 13 ..., rotor disk 14 ... chip, C, C1, C2 ... heating coil 21 ... vacuum furnace, 22 ... moving blade, 23 ... parts stand

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Junichiro Maedoma             2-4 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa               Toshiba Keihin Office F-term (reference) 4K042 AA25 BA13 DA03 DB01 DC04                       DC05

Claims (10)

[Claims] 1. A softening heat treatment method for a gas turbine blade, in which a region including a tip of a blade is locally heated to a solution temperature by a high frequency induction heating operation when the region including a tip of the blade is subjected to a softening heat treatment. . 2. The blade and the dummy blade are prepared, the tip of the dummy blade is brought into contact with the tip of the blade, and heated to a predetermined temperature by a high frequency induction heating operation. Method for softening heat treatment of gas turbine blade. 3. A first blade and a second blade are prepared, the tip of the second blade is brought into contact with the tip of the first blade, and heated to a predetermined temperature by a high frequency induction heating operation. The softening heat treatment method for a gas turbine blade according to claim 1, wherein 4. The softening heat treatment method for a gas turbine blade according to claim 2, wherein a region including the tip of the blade is heated in an inert gas atmosphere. 5. When there is a temperature difference between a region including the tip of the blade and the dummy blade, the high frequency induction heating coil is moved from the blade on the high temperature side to the blade on the low temperature side for heating. The softening heat treatment method for a gas turbine blade according to claim 2 or claim 3, characterized in that. 6. A blade and a dummy blade are prepared, the tip of the dummy blade is brought into contact with the tip of the blade via an intermediate member, and the blade is heated to a predetermined temperature by a high frequency induction heating operation. Item 2. A softening heat treatment method for a gas turbine blade according to Item 1. 7. At least three blades are prepared, the tips of the blades are brought into contact with each other, and the contacted portions of the blades are individually or simultaneously heated by a high frequency induction heating operation. The softening heat treatment method for a gas turbine blade according to claim 1. 8. A blade and a dummy blade made of a material having a heat generation characteristic superior to that of the blade by a high-frequency induction heating operation are prepared, and the tip of the dummy blade is brought into contact with the tip of the blade to perform high-frequency induction heating. The method for softening heat treatment of a gas turbine blade according to claim 1, wherein heating is performed to a predetermined temperature. 9. A diffusion barrier is formed at the tip of the dummy blade, and the tip of the dummy blade is brought into contact with the tip of the blade so that the tip surface of the blade comes into contact with the diffusion barrier and heated to a predetermined temperature. The softening heat treatment method for a gas turbine blade according to claim 8, wherein 10. A blade having an implant portion fixed to a rotor disk and having chips in contact with each other in a circumferential direction is prepared, and a region including the chips is heated to a predetermined temperature by a high frequency induction heating operation. The softening heat treatment method for a gas turbine blade according to claim 1.