JP2003315252A - Life evaluating method for heat shield coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a life evaluating method for heat shield coating that accurately and properly estimates the falling-off and the separation of the heat shield coating to be able to ponder well plans for repair or replacement in advance, to a next periodical inspection. <P>SOLUTION: When predicting the falling-off area of the heat shield coating until the next periodical inspection thereby, where high temperature parts are coated with the heat shield coating consisting of anticorrosion alloy and ceramics, the life evaluating method for the heat shield coating measures the falling- off area of the heat shield coating (ST1), collates the data of the measured falling-off area of the heat shield coating with data from a master curve based on temperature stress (ST2) and data from heat shield coating damage data base (ST3), calculates the falling-off progress speed of the heat shield coating (ST4), multiplies by an operating time based on the falling-off progress speed of the heat shield coating (ST5), compensates based on the thickness of an oxide layer generated between the anticorrosion alloy and the ceramics (ST6), and calculates the falling-off area of the heat shield coating until the next periodical inspection to predict (ST7). <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for evaluating the life of a thermal barrier coating used in a high temperature oxidizing or corrosive atmosphere such as a gas turbine for power generation or a jet engine for aviation.

[0002]

2. Description of the Related Art For example, in the field of prime movers such as gas turbines for power generation and jet engines for aeronautics, research and development are being pursued in order to further improve thermal efficiency, and gas turbines are one means for improving thermal efficiency. There is an even higher temperature of the driving combustion gas.

One of the means for achieving a higher temperature of combustion gas is to coat a high temperature member used for a high temperature component of a gas turbine such as a gas turbine stationary blade, a gas turbine moving blade or a gas turbine combustor. There is development of the coating member to do.

The coating of the high temperature parts is a means for improving the heat resistance by coating the base material of the parts with the thermal barrier coating member without changing the metal composition structure. Here, thermal barrier coating (abbreviated as TB)
C) is for coating the surface of the base material of the component with a low heat conductive member such as ceramics, and suppressing the temperature rise of the base material of the component via the heat conductive member.

Thermal barrier coatings have already been applied to some of the high temperature components of gas turbines, such as gas turbines for power generation and jet engines for aviation.

Recently, MCrAl having excellent adhesion, corrosion resistance, and oxidation resistance on the surface of a superalloy substrate.
A combination of an alloy underlayer and a thermal barrier coating composed of an oxide-based ceramics layer such as zirconia having low thermal conductivity is also used.

By the way, since the thermal barrier coating has the function of suppressing the temperature rise of the base material of the component, it should not be peeled or dropped from the base material of the component, but it has been used for many years. As a result of use, it may be peeled off or fallen off due to the influence of oxidation.

Several inspection methods have been implemented for the peeling or dropping of the thermal barrier coating member from the substrate of the component.

In these inspection methods carried out, the difference in the surface condition between the position where the coating film is removed and the position where it is not removed is observed and recorded, or a video is taken using a CCD camera or the like. There are visual inspections and penetrant inspections for inspecting cracks that occur directly on the coating film.

In addition, recently, Japanese Patent Laid-Open No. 11-16691
As can be seen in Japanese Patent Publication No. 0, there are some which are inspected using an infrared camera.

Further, recently, the degree of deterioration of the coating film before it is removed is evaluated not only in the inspection of the coating film, but also as shown in, for example, Japanese Unexamined Patent Publication No. 7-310501 and 2000-206100. Things have been proposed.

[0012]

The above-mentioned coating film drop-out inspection method is used properly according to the degree of inspection difficulty such as the shape and position of the object to be inspected and the degree of progress of deterioration, but there are still some problems. Was included.

First, the visual inspection cannot be detected until the coating film comes off. At the position where the coating film has fallen off, the thermal barrier properties and oxidation resistance of the coating film are completely impaired. Therefore, it is necessary to detect peeling, which is a precursor of the coating film falling off, but it is difficult to detect peeling by visual inspection.

Further, the penetrant flaw detection method for inspecting cracks generated in the coating film can detect cracks opened on the surface of the coating film, but cannot detect detachment of the coating film. In the case of a gas turbine, since the thermal barrier coating has many pores in the coating, it is difficult to detect only cracks because the permeate penetrates into the pores.

On the other hand, the inspection method using an infrared camera disclosed in Japanese Patent Application Laid-Open No. 11-166910 can detect the peeling of the coating film. Moreover, for example, it is possible to inspect with an inspected object having a complicated shape such as a turbine blade.

However, it is necessary to carry the object to be inspected onto the inspection device, and the turbine blade cannot be inspected if it remains implanted in the turbine rotor (turbine shaft).

Further, since the structure is such that the object to be inspected is installed on an inclined or rotary table, it is necessary to increase the withstand load of the stage in order to inspect heavy objects such as turbine blades of a large turbine. Manufacturing and operating costs are high.

Further, since the position of the heating device cannot be controlled, it takes a lot of time to set the heating conditions suitable for the inspection.

On the other hand, in Japanese Patent Laid-Open No. 7-310501, ultrasonic waves are used for the third degree of deterioration diagnosis.

In the gas turbine, the interface between the thermal barrier coating and the substrate is 0.2 to 0.5 m from the surface of the thermal barrier coating.
Since the thermal barrier coating has a very shallow depth of about m and unevenness is present on the surface of the thermal barrier coating, it is difficult to directly detect peeling by ultrasonic waves.

A method has also been proposed in which an echo that passes through the interface between the thermal barrier coating and the base material and is reflected on the bottom surface of the base material is captured. However, in the case of a gas turbine component, a cooling passage groove is provided inside. Since it is formed, the thickness up to the bottom surface of the base material varies from place to place, which complicates ultrasonic inspection.

Further, since the gas turbine rotor blade and the like have a complicated curved surface shape, a complicated mechanism for scanning the probe along the blade surface is required, which is not suitable for on-site inspection.

Further, Japanese Patent Laid-Open No. 2000-20610 also uses ultrasonic waves for destructive inspection of the peeling damage condition.
As above, it is not suitable for on-site inspection.

As described above, the conventional methods for evaluating the life of thermal barrier coatings have some problems, and new improvements have been demanded.

The present invention has been made under such circumstances, and accurately grasps the thermal barrier coating from falling off and peeling off accurately, and at the time of the next periodic inspection, a repair or replacement plan is made in advance. It is an object of the present invention to provide a method for evaluating the life of a thermal barrier coating that enables sufficient kneading.

[0026]

A method for evaluating the life of a thermal barrier coating according to the present invention is as described in claim 1.
When predicting the falling area of the thermal barrier coating including each layer made of corrosion-resistant alloy and ceramics, the step of measuring the falling area of the thermal barrier coating, and the data of the measured thermal barrier coating falling area, the master curve based on the temperature stress Calculating the drop-off rate of the thermal barrier coating by comparing the data from the above and the data from the thermal barrier coating damage database, multiplying the calculated drop-off rate of the thermal barrier coating by the operating time, and And a step of correcting the speed based on the thickness of an oxide layer formed between the alloy and the ceramics.

According to the method of evaluating the life of a thermal barrier coating according to the present invention, as described in claim 2, when predicting the peeled area of the thermal barrier coating provided with each layer consisting of a corrosion resistant alloy and ceramics, Compare the peeling area of the thermal barrier coating with the process of measuring the peeling area and the measured thermal barrier coating peeling area data against the data from the master curve based on temperature stress and the data from the thermal barrier coating damage database. A step of calculating, a step of multiplying the calculated delamination progress rate of the thermal barrier coating by an operating time, and a step of correcting the rate based on the thickness of an oxide layer formed between the corrosion resistant alloy and the ceramics. It is characterized by including.

In the method for evaluating the life of a thermal barrier coating according to the present invention, as described in claim 3, the thermal barrier coating damage database stores the actual damage state obtained by the inspection,
It is characterized by using the data stored in the thermomechanical fatigue test using the test piece with the thermal barrier coating.

In the method for evaluating the life of a thermal barrier coating according to the present invention, as described in claim 4, the master curve based on the temperature stress is prepared in advance by calculating the stress based on the temperature. Claim 1 or 2 characterized by the above-mentioned.
A method for evaluating the life of the thermal barrier coating described.

In the method for evaluating the life of a thermal barrier coating according to the present invention, as described in claim 5, the correction based on the thickness of the oxide layer formed between the corrosion resistant alloy and the ceramic is:
It is characterized in that it is calculated from the exfoliation peeling master curve based on the thickness of the oxide layer which is created in advance.

In the method for evaluating the life of a thermal barrier coating according to the present invention, as described in claim 6, an infrared camera is used to measure the peeled area of the thermal barrier coating.

In the method for evaluating the life of a thermal barrier coating according to the present invention, as described in claim 7, the thickness of the oxide layer formed between the corrosion-resistant alloy and the ceramics is the AC current applied to the coil mounted on the ceramics. Is energized and measured based on the amount of impedance change.

In the method for evaluating the life of a thermal barrier coating according to the present invention, as described in claim 8, the coil is provided with a pair for excitation and a pair for detection for detecting a change in impedance. Characterize.

The method for evaluating the life of a thermal barrier coating according to the present invention is characterized in that, as described in claim 9, the thickness of the oxide layer formed between the corrosion resistant alloy and the ceramic is not covered with the thermal barrier coating. Apply a current to the exposed part,
The feature is that the change in impedance is detected by the probe.

According to a tenth aspect of the present invention, there is provided a method for evaluating the life of a thermal barrier coating, wherein either one of the falling area and the peeled area of the thermal barrier coating provided with each layer consisting of a corrosion resistant alloy and ceramics is used. When predicting, the method is characterized by including a step of measuring the residual stress on the surface of the thermal barrier coating and a step of calculating the internal stress between the corrosion resistant alloy and the ceramic layer interface from the measured residual stress.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the method for evaluating the life of a thermal barrier coating according to the present invention will be described below with reference to the drawings and the reference numerals attached to the drawings.

FIG. 1 is a flow chart for explaining the first embodiment of the method for evaluating the life of a thermal barrier coating according to the present invention.

Life of the thermal barrier coating according to the present embodiment
The evaluation method is the heat shield dropped from the base material (base material) of the high temperature parts.
Thermal barrier coating removal to measure the coating loss area
Drop area measurement process (ST1) and measured thermal barrier coating
The data of the stress dropout area (ST2) can be
Data from the Star Curve and damage data for the thermal barrier coating
Check the data from the database process (ST3)
The thermal barrier coating that calculates the rate of dropout development of the thermal barrier coating
Calculated with the Ting drop-off rate calculation step (ST4)
Multiply the operating time etc. based on the dropout speed (ST5).
In addition, the thickness of the oxide layer is taken into consideration for correction (ST6), and the next
Insulation that predicts the area where the thermal barrier coating will fall off during regular inspections
Equipped with a thermal coating falling area prediction step (ST7)
It is configured.

Thermal barrier coating falling area measurement step (ST
Although 1) is mainly performed by visual inspection, a magnifying glass or the like may be used.

In the stress calculation step (ST2), the stress is calculated in advance based on the temperature of the high temperature component, and the calculated stress is graphed and summarized. For example, as shown in FIG. It is used as a speed master curve.

In the thermal barrier coating drop-off rate calculating step (ST4), the thermal barrier coating drop-off area developing rate master curve previously created in the stress calculating step (ST2) is used. As shown, the temperature and the rate at which the thermal barrier coating falls are calculated.

In obtaining the thermal barrier coating falling area development rate, the data from the thermal barrier coating damage database step (ST3) is referred to.

In the thermal barrier coating damage database step (ST3), the damage state of the actual machine obtained from the past periodical inspection, the data of the thermomechanical fatigue test using the test piece with the thermal barrier coating, etc. are stored. There is.

The damage state of the actual machine is data for grasping the damage state under the actual plant operating environment. Further, the data obtained by the thermomechanical fatigue test is data for grasping the damage behavior of the thermal barrier coating under a predetermined temperature stress condition.

Therefore, in the thermal barrier coating falling-off rate calculating step (ST4), the thermal barrier coating falling-off area developing rate obtained from the thermal barrier coating falling-off area developing rate master curve is calculated from the thermal barrier coating damage database step (ST3). Since the final thermal barrier coating falling area development speed is set with reference to the data of 1, the more accurate thermal barrier coating falling development speed can be set.

The thermal barrier coating loss rate value calculated in the thermal barrier coating loss rate calculation step (ST4) is
In the next periodical inspection dropout prediction step (ST5), the running time or the number of start / stop times is multiplied, and as shown in FIG. 6, for example, the heat shield coating dropout area is calculated from the dropoff area estimation master curve created in advance. presume.

FIG. 2 and FIG. 3 are schematic diagrams in which the degree of progress of the exfoliation area A and the exfoliation area B of the thermal barrier coating are compared with each other by taking the turbine blade 1 as an example. Note that FIG.
FIG. 3 is a schematic diagram showing a peeling area A and a falling area B of the thermal barrier coating at the present time. Further, FIG. 3 is a schematic diagram showing a peeling area A and a falling area B of the thermal barrier coating in the next regular inspection.

2 and 3 are compared with each other, it can be seen that peeling and dropping of the thermal barrier coating are progressing. The progress of these is shown in the next regular dropping prediction process (ST).
It is calculated from 5).

On the other hand, the thermal barrier coating loss area calculated in the next regular loss estimation step (ST5) is corrected in the thermal coating loss amount correction step (ST6).

Generally, for example, ceramics is used as the thermal barrier coating, and the base material (base material) of the turbine blade 1 is used.
As an example, when using a corrosion-resistant alloy, the oxide layer of the corrosion-resistant alloy has a close correlation with the damage of the thermal barrier coating, and when the thickness of the oxide layer becomes a constant value, the falling probability and the peeling probability of the thermal barrier coating are It is known to rise sharply.

The amount of oxidation of the corrosion resistant alloy is expressed by a function of the test temperature of the sample and the operating time, and can be calculated. However, considering that damage such as dropping of the thermal barrier coating may occur, It is desirable to measure directly with a sample.

To measure the thickness of the oxide layer of the corrosion resistant alloy, the overcurrent method is used as shown in FIG. The thermal barrier coating covers, for example, the base material 2 of the turbine blade 1 with the corrosion-resistant alloy layer 3 and the ceramics layer 4. Then, due to the high temperature environment during operation, the oxide layer 5 is generated in the corrosion resistant alloy layer 3.

When the oxide layer 5 is formed in the corrosion resistant alloy layer 3, the coil 6 is attached to the ceramic layer 4 and an alternating current is passed through the coil 6. Since the ceramics layer 4 is non-conductive, an overcurrent is generated only in the corrosion resistant alloy layer 3 and the base material 2. When the overcurrent occurs, the impedance of the coil 6 changes. Since the oxide layer 5 has some conductivity, the thickness of the oxide layer 5 can be easily measured by measuring the amount of change in impedance.

When measuring the thickness of the oxide layer 5 by using the overcurrent method, as shown in FIG. 8, the exciting coil 7 and the detecting coil 8 for detecting a change in impedance are paired to form a ceramic. It may be mounted on the layer 4, or, as shown in FIG. 9, the probe 9 having a built-in coil is directly energized through the lead wire 10 to the subject 9 of the exposed metal portion which is not covered with the thermal barrier coating. The thickness of the oxide layer 12 may be measured by measuring the change in impedance with the probe 11.

The former is effective in that the excitation coil 7 and the detection coil 8 are separately attached, and therefore the information of the subject 9 can be detected more accurately, and the latter is effective in exposing the base material 2. In this case, it is effective in that it can be easily measured.

When the thickness of the corrosion-resistant alloy layer 3 is measured in this manner, the thermal barrier coating falling area correction step (ST6) is prepared in advance based on this data as shown by the broken line in FIG. A correction value is calculated from the falling peeling master curve based on the oxide layer thickness.

When the correction value is calculated, the thermal barrier coating falling area predicting step (ST7) is carried out in the thermal barrier coating falling rate calculating step (ST4) and the next regular falling rate predicting step (ST5). Estimate the exfoliation and peeling area of the thermal barrier coating by correcting it by adding the correction to the exfoliation area obtained from the master curve.

As described above, in this embodiment, the thermal barrier coating drop-off progress rate is calculated by utilizing the temperature and stress diagram and the data in the thermal barrier coating damage database for the measured thermal barrier coating drop-off area. By multiplying the calculated thermal barrier coating drop-off rate by the operating time until the next regular inspection, calculate the drop-off area from the master curve, and then make a correction based on the thickness of the oxide layer generated in the corrosion-resistant alloy layer. Since the area where the thermal barrier coating is lost during the next regular inspection is predicted, it is possible to accurately predict the area where the thermal barrier coating is lost, and it is possible to formulate a repair or replacement plan for the next regular inspection in advance. The time can be further shortened.

In this embodiment, the thermal barrier coating falling area has been described, but the present invention is not limited to this example, and the thermal barrier coating peeling area can be calculated using the same method as described above.

For convenience of explanation, the method for calculating the peeled area of the thermal barrier coating will be described again with reference to FIG.

The thermal barrier coating peeling area calculation method according to the present embodiment comprises a thermal barrier coating peeling area measuring step (ST8) for measuring the peeling area of the thermal barrier coating peeled from the base material of the high temperature component, and the measured thermal barrier coating area. The data from the stress calculation step (ST2) and the thermal barrier coating damage database step (ST3) are used as the data of the coating peeling area.
The thermal barrier coating peeling progress rate calculation step (ST9) for calculating the peeling progress rate of the thermal barrier coating on the basis of the data from and the operating time based on the calculated peeling progress rate. As shown in the figure, the peeling area is calculated in advance from the falling peeling area master curve (S
T5), and further correction is performed in consideration of the thickness of the oxide layer (ST
6), the thermal barrier coating peeling area prediction step (ST10) of calculating and predicting the peeling area of the thermal barrier coating in the next regular inspection.

Thermal barrier coating peeling area measuring step (ST
8) is the above-mentioned thermal barrier coating falling area measurement step (S
Unlike T1), the infrared method is used.

In the infrared method, the object is heated by a heater such as a halogen lamp, and the temperature distribution on the surface of the thermal barrier coating during heating is measured by an infrared camera. At this time, in the healthy part of the subject, heat is transferred to the base material through the thermal barrier coating, but in the peeling part, the heat conduction is poor, so the heat stays on the surface of the thermal barrier coating. That is, there is peeling of the thermal barrier coating where it is detected as a high temperature portion by the infrared camera. By measuring the area of this high temperature portion on the image, the peeled area of the thermal barrier coating can be measured.

When the peeled area is measured, a temperature / stress diagram created in advance in the stress calculation step (ST2),
In comparison with the data from the thermal barrier coating damage database step (ST3), the thermal barrier coating peeling progress rate calculating step (ST9) calculates the peeling area developing rate of the subject.

In the case where both the thermal barrier coating is removed and peeled off in the same portion of the object, the thermal barrier coating peeling progress rate calculation step (ST9) is performed to separate the thermal barrier coating from the removed area. To calculate. Note that the other steps are the same as the method of the steps shown in the first embodiment, and thus their duplicate description will be omitted.

As described above, in this embodiment, the thermal barrier coating peeling progress rate is calculated by utilizing the temperature and stress diagram and the data of the thermal barrier coating damage database in the measured thermal barrier coating peeling area. , The calculated thermal barrier coating peeling speed is multiplied by the operating time until the next regular inspection, and correction is performed based on the thickness of the oxide layer formed in the corrosion-resistant alloy layer to remove the thermal barrier coating for the next regular inspection. Since the area is calculated and predicted, the peeling area of the thermal barrier coating can be accurately predicted, and the repair or replacement plan at the next regular inspection can be planned in advance, further shortening the regular inspection work time. be able to. In particular,
The present embodiment is effective in that it is possible to calculate the removal and peeling of the thermal barrier coating from the base material in parallel at the same time.

FIG. 10 is a flow chart for explaining the third embodiment of the thermal barrier coating life evaluation method according to the present invention.

The method of evaluating the life of a thermal barrier coating according to the present embodiment comprises a thermal barrier coating surface residual stress measurement step (step 1), a stress estimation calculation step (step 2) between the corrosion resistant alloy layer and the ceramics layer interface, It is configured to include a thermal barrier coating removal life calculation step (step 3).

In the thermal barrier coating surface residual stress measuring step (step 1), the residual stress on the thermal barrier coating surface is measured by using, for example, X-rays.

Although the tensile stress at the time of manufacture remains on the surface of the thermal barrier coating, stress relaxation tends to occur due to thermal history due to operation, and the stress value tends to gradually decrease.

The oxide layer formed on the corrosion resistant alloy layer also reduces the residual stress on the surface of the thermal barrier coating.

Therefore, the residual stress on the surface of the thermal barrier coating decreases with the increase of the operating time or the number of times of starting and stopping, but it is based on that the residual stress still remains.

Next, in the stress estimation calculation step (step 2) between the corrosion resistant alloy layer and the ceramics layer interface, the internal stress between the corrosion resistant alloy layer and the ceramics layer interface is calculated from the measured residual stress value on the surface of the thermal barrier coating. Predict.

The residual stress in the thermal barrier coating is highest at the surface and lowest at the interface of the corrosion resistant alloy layer. If this stress gradient is analyzed and obtained in advance by experiments and manufacturing simulations, the internal stress between the ceramic layer and the corrosion resistant alloy layer interface can be estimated from the residual stress on the surface of the thermal barrier coating.

Finally, in the thermal barrier coating dropout life calculation step (step 3), the lifetime until the thermal barrier coating falls out is predicted from the calculated internal stress between the corrosion-resistant alloy layer and the ceramics layer. Since the internal stress at the interface between the ceramics layer and the corrosion resistant alloy layer has a close correlation with the loss of the thermal barrier coating, the loss life of the thermal barrier coating can be predicted if the internal stress is known.

The peeling life of the thermal barrier coating can be easily calculated using the same method as described above.

As described above, in this embodiment, the residual stress of the thermal barrier coating is measured, the internal stress between the corrosion resistant alloy layer and the ceramics layer interface is calculated from the measured residual stress, and the thermal barrier coating is calculated from the calculated internal stress. Since either one of the falling life and the peeling life of the thermal barrier coating is predicted, it is possible to easily predict the falling life and the peeling life of the thermal barrier coating by a simple method.

In this embodiment, the life of the thermal barrier coating falling off the base material was estimated, but if this data is applied to, for example, the above-described first embodiment, the area of the thermal barrier coating falling off, etc. Can be calculated more accurately.

[0079]

As described above, the method for evaluating the life of a thermal barrier coating according to the present invention is applied to the thermal barrier coating for covering high temperature parts, including the dropout area, peeling area and dropout life until the next regular inspection. Since either of them is calculated using the measurement data, the diagram, and the database, the repair or replacement plan for the next regular inspection can be planned in advance, and the regular inspection work time can be further shortened.

[Brief description of drawings]

FIG. 1 is a flow diagram illustrating a first embodiment and a second embodiment of a method for evaluating the life of a thermal barrier coating according to the present invention.

FIG. 2 is a schematic view showing a peeling area and a falling area of the thermal barrier coating at the present time.

FIG. 3 is a schematic diagram showing a peeling area and a falling area of the thermal barrier coating in the next regular inspection.

FIG. 4 is a master curve of thermal barrier coating drop-off area development rate applied to the thermal barrier coating life evaluation method according to the present invention.

FIG. 5 is a falling-off peeling area master curve for calculating a correction value based on the thickness of an oxide layer applied to the life evaluation method for a thermal barrier coating according to the present invention.

FIG. 6 is a falling / peeling area master curve for estimating the falling area and the peeling area based on the operating time and the like applied to the method for evaluating the life of a thermal barrier coating according to the present invention.

FIG. 7 is a schematic diagram for measuring an oxide layer thickness generated at an interface between a ceramic layer and a corrosion resistant alloy layer by an overcurrent method using a single coil, which is applied to a life evaluation method for a thermal barrier coating according to the present invention.

FIG. 8 is an oxide layer thickness generated at an interface between a ceramic layer and a corrosion-resistant alloy layer by an overcurrent method using two coils arranged concentrically, which is applied to a life evaluation method for a thermal barrier coating according to the present invention. Schematic diagram for measuring the height.

FIG. 9 is a schematic diagram for measuring the thickness of an oxide layer formed at the interface between a ceramics layer and a corrosion-resistant alloy layer by an overcurrent method in which a current is applied to a subject.

FIG. 10 is a flow diagram illustrating a third embodiment of the method for evaluating the life of a thermal barrier coating according to the present invention.

[Explanation of symbols]

1 ... Turbine blade, 2 ... Base material (base material), 3 ... Corrosion resistant alloy layer,
4 ... Ceramics layer, 5 ... Oxidation layer, 6 ... Coil, 7 ... Excitation coil, 8 ... Detection coil, 9 ... Subject, 10 ... Lead wire, 11 ... Probe, 12 ... Oxidation layer.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazunari Fujiyama             2-4 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa               Toshiba Keihin Office (72) Inventor Keisuke Takagi             2-4 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa               Toshiba Keihin Office F-term (reference) 2G050 AA02 BA10 BA12 CA02 DA03                       EA01 EA04 EB02 EB07 EC01                 2G053 AA14 AB21 BA19 BB11 BC02                       BC14 CA03 CA17

Claims (10)

[Claims] 1. When predicting the falling area of a thermal barrier coating provided with each layer consisting of a corrosion resistant alloy and ceramics,
The step of measuring the falling area of the thermal barrier coating and the measured thermal barrier coating falling area data are compared with the data from the master curve based on the temperature stress and the data from the thermal barrier coating damage database. The step of calculating the drop-off rate, the step of multiplying the calculated drop-off rate of the thermal barrier coating by the operating time, and the rate based on the thickness of the oxide layer formed between the corrosion-resistant alloy and the ceramics. The method of evaluating the life of a thermal barrier coating, comprising: 2. When predicting the peeling area of a thermal barrier coating comprising layers of corrosion resistant alloy and ceramics,
The step of measuring the peeling area of the thermal barrier coating and the measured thermal barrier coating peeling area data are compared with the data from the master curve based on the temperature stress and the data from the thermal barrier coating damage database. And a step of multiplying the calculated peeling growth rate of the thermal barrier coating by an operating time, and the rate based on the thickness of an oxide layer formed between the corrosion resistant alloy and the ceramics. The method of evaluating the life of a thermal barrier coating, comprising: 3. The thermal barrier coating damage database comprises:
3. The thermal barrier coating according to claim 1, wherein an actual damage state obtained by inspection and data of a thermomechanical fatigue test using a test piece on which a thermal barrier coating is applied are stored. Life evaluation method. 4. The method of evaluating the life of a thermal barrier coating according to claim 1, wherein the master curve based on temperature stress is created in advance by calculating stress based on temperature. 5. The correction based on the thickness of the oxide layer formed between the corrosion-resistant alloy and the ceramics is calculated from a drop-off master curve based on the thickness of the oxide layer that is created in advance. Alternatively, the method for evaluating the life of the thermal barrier coating described in 2 above. 6. The peeled area of the thermal barrier coating is measured by
An infrared camera is used, The lifetime evaluation method of the thermal barrier coating of Claim 2 characterized by the above-mentioned. 7. The thickness of the oxide layer formed between the corrosion resistant alloy and the ceramics is measured based on the amount of impedance change by passing an alternating current through a coil mounted on the ceramics. 1. A method for evaluating the life of a thermal barrier coating according to 1 or 2. 8. The method for evaluating the life of a thermal barrier coating according to claim 1, wherein the coil is provided with a pair for excitation and a pair for detection for detecting a change in impedance. 9. The thickness of the oxide layer formed between the corrosion-resistant alloy and the ceramic is such that a change in impedance can be detected by a probe by passing a current through an exposed metal portion not covered with a thermal barrier coating. Claim 1 or 2 characterized
A method for evaluating the life of the thermal barrier coating described. 10. A step of measuring a residual stress on the surface of the thermal barrier coating when predicting either one of a falling area and a peeling area of the thermal barrier coating including each layer made of a corrosion resistant alloy and ceramics, and measuring the residual stress. Calculating the internal stress between the corrosion resistant alloy and the ceramics layer interface from the residual stress.