JP2002277383A - Method of evaluating coating strength - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily evaluate strength of an executed coating even in an actual component of a complicated shape. SOLUTION: A degree of damage in the coating and adhesive strength of the coating are evaluated by a degree of separation between the coating and a base material or a bond coating generated when impact force is applied under a fixed condition onto a sample executed with the coating supplied for evaluation, and by critical energy generating the separation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the adhesion strength of a coating of a thermal power generation device, particularly a gas turbine component.

[0002]

2. Description of the Related Art In a rotating device, for example, a gas turbine, a rotating force is obtained by a combustion gas flowing at a high temperature and a high speed. .

In general, a gas turbine guides discharge air compressed by a compressor 41 provided coaxially with the gas turbine to a gas turbine combustor 42 as shown in FIG. Then, the combustion gas is guided from the liner to the moving blade 45 via the transition piece 43 and the stationary blade 44, and is driven and exhausted after driving the gas turbine.

[0004] In such a gas turbine, the combustion gas, which has become high temperature and high pressure, applies a rotating force to the rotor via the blades while decreasing the temperature and pressure in each stage of the turbine. In other words, the motive power is transmitted to the rotor shaft via the turbine blades by the above-mentioned fluid. However, in recent years, the efficiency of the power plant has increased, the working fluid amount of the turbine has increased due to the increase in capacity, and the operating conditions due to the high temperature have increased. As a result, various forces acting on the rotor blades during operation have become increasingly severe.

[0005] These forces cause stresses such as centrifugal stress, thermal stress, bending stress and torsion stress in the turbine blade,
These stresses can work together or individually to cause high stresses.

[0006] Further, since the strength of a material generally decreases as the temperature increases, the material becomes increasingly severe under use conditions in which the gas temperature increases. For this reason, a blade or the like exposed to a high-temperature gas is frequently cracked by repeated thermal stress generated on the surface, and is frequently damaged by oxidative corrosion. In order to prevent this, in recent years, coatings have been applied to the surfaces of these high-temperature components to prevent oxidation and reduce thermal stress.

[0007] Particularly in a gas turbine which is heated to a high temperature,
Thermal barrier coatings are being applied to reduce thermal stress and operating temperature. This coating is composed of a top coat of the outermost layer mainly composed of a heat-resistant ceramic such as zirconia and a bond coat for bonding the component base material.

As shown in FIG. 18A, when used at the same gas temperature, if there is no coating, the substrate is directly exposed to a high-temperature gas. Although the temperature difference from the inner wall temperature is small, when the surface is coated as shown in FIG. 18 (b), the base material is directly exposed to the high-temperature gas due to the temperature drop in the coating having low thermal conductivity. Therefore, the temperature difference between the temperature on the gas flow path side and the temperature of the inner wall on the cooling side becomes large, and it is possible to use at a higher temperature.

However, as described above, the thermal barrier coating has a high effect on environmental resistance and reduction of thermal stress, but the coating may peel or fall off due to various damages due to aging.

FIG. 19 shows an example of damage due to oxidation or thermal stress. Since the top coat is made of ceramics and the base material is made of a metal material, when heated and cooled, a difference in linear expansion coefficient causes cracks in the coating in the vertical direction,
Further, minute cracks are generated in the lateral direction due to the unevenness of the coating interface.

[0011] These cracks cause the coating to peel off and fall off due to an external force such as a driving force or a centrifugal force of the oxide layer generated in the bond layer. If the topcoat falls off locally, the bond coat or substrate will be directly exposed to the hot gas, causing the temperature to rise locally, causing damage to the entire part.

For this reason, there has been an important technical problem in that a method of detecting peeling or falling off of the thermal barrier coating in advance and evaluating the degree of damage is important.

Further, it is very important to evaluate the strength of these thermal barrier coatings from the stage of their application and to grasp the adhesion strength and breaking strength in applying these coatings. This is because the top coat of the coating is usually applied by a method such as thermal spraying of ceramics with high heat resistance, considering the oxidizing and corrosive properties of the combustion gas from the usage environment, as well as oxides and the like that fly with the combustion gas. Impact resistance to flying objects should also be fully considered.

In general, a filter for removing foreign matter in the air is provided in an air intake section of a gas turbine. However, if the filter is deteriorated or oxidized scale is generated in the gas turbine downstream of the filter, foreign matter is mixed into the combustion gas and collides with the stationary blade or the moving blade. These foreign substances have a small mass but a high collision velocity. Particularly, as the velocity of the foreign substances decreases, the relative collision velocity increases with respect to the rotor blades, so that a large amount of damage is caused.

[0015] For this reason, it is very important to grasp the damage of the thermal barrier coating due to the foreign matter collision in the selection of the allowable size, material and coating material of the foreign matter.

[0016]

As described above, the thermal barrier coating has a high effect on environmental resistance and reduction of thermal stress, but the coating is peeled off or falls off due to various damages due to aging.

Further, since the top coat is made of ceramics as described above and the base material is a metal material, thermal stress is generated in the coating due to the difference in the coefficient of linear expansion when heated and cooled. Furthermore, because of the unevenness at the interface of the coating, thermal stress is also generated in the direction perpendicular to the interface, and a crack is generated in the direction perpendicular to the coating along with the vertical crack along the coating.

[0018] These cracks act as initial cracks in the cracks that cause the coating to delaminate. At the same time, an oxygen layer is formed in the bond layer by oxygen that has penetrated through the top coat, and the formation of the oxide layer causes a crack to grow due to its body force.

Further, the coating is peeled off and dropped off by an external force such as a centrifugal force acting on the rotor blade itself. If the topcoat falls off locally, the bond coat or substrate will be directly exposed to the hot gas, causing the temperature to rise locally, causing damage to the entire part.

For this reason, an important technical problem is a method of detecting peeling or falling off of the thermal barrier coating in advance and evaluating the degree of thermal fatigue damage. In particular, if the degree of damage can be evaluated at the stage where minute cracks are formed in the coating due to repeated thermal stress, peeling and falling off of the coating can be predicted in advance, so that the effect is large.

Further, it is very important to evaluate the strength of these thermal barrier coatings from the stage of their application and to grasp their adhesion strength and breaking strength in applying these coatings. This is because the top coat of the coating is usually formed by spraying a ceramic having high heat resistance by a method such as thermal spraying, and the impact resistance to flying objects such as oxides flying with the combustion gas must be sufficiently considered.

Generally, foreign matter such as oxide scale flowing into the gas turbine enters the combustion gas and collides with the stationary blades and the moving blades, causing a great deal of damage. These foreign substances have a small mass but a high collision velocity. Particularly, as the velocity of the foreign substances decreases, the relative collision velocity increases with respect to the rotor blades, so that a large amount of damage is caused.

For this reason, it is very important to grasp the damage of the thermal barrier coating due to the foreign matter collision in the selection of the allowable size, material and coating material of the foreign matter.

The present invention has been made in view of the above circumstances, and quantitatively evaluates the degree of damage of a thermal barrier coating due to thermal fatigue and aging of members, and peels off the coating.
An object of the present invention is to provide a method for evaluating coating strength, which can predict dropout in advance.

[0025]

In order to achieve the above object, the present invention evaluates coating strength by the following method.

According to the present invention, the magnitude of the separation between the coating and the substrate or the bond coat generated when an impact force is applied to the sample on which the coating to be evaluated has been applied under a certain condition, and the critical energy at which the coating is separated are determined. It is characterized by evaluating the degree of damage and adhesion strength.

In this case, the impact force is applied several times while changing the impact speed to obtain the relationship between the impact speed or impact energy and the amount of the coating peeled off. Since the peeling of the coating cannot be measured in appearance, it is measured as the peeling area or the maximum length of the peeled portion by nondestructive measurement. From the relationship between the impact energy and the amount of peeling, the degree of damage and adhesion strength of the coating are evaluated.

Therefore, in the method of the present invention, the degree of damage and the adhesion strength of the coating are evaluated by applying an impact force to the coating and destroying the most fragile portion of the coating or the substrate. In other words, the damage that occurs in the coating due to thermal fatigue, etc., is vertical cracks that occur along the coating and horizontal cracks that occur in the direction perpendicular to the coating. The application of a strong external force results in delamination cracks and coating shedding that are clearly detected.

The impact force is given by the impact of the sphere on the coating sample. The force varies depending on the impact speed, and the size of the peeling cracks and falling off also varies. The amount and adhesion strength are evaluated based on the relationship between the impact energy and the peel amount. One index is the limit energy, and the limit energy is determined from data obtained from several tests under the condition that there is no peeling amount. Alternatively, the damage and adhesion strength of the coating are evaluated using the amount of peeling at a constant impact energy as an index.

Further, the present invention is characterized in that when the material properties of the coating are known, the coating is evaluated by finite element analysis corresponding to this experiment.

Therefore, in the present invention, the amount of peeling is evaluated from the strain and stress generated in each part of the coating at the time of collision with a sphere by setting the basic material deformation characteristics and breaking conditions of the coating and the base material. Further, a shear strain is selected as a strain that causes peeling, and a peeling area is determined from the spread of the strain. Further, by providing an element that disappears when a certain strain is reached in a portion where peeling occurs, an analysis simulating a peeling crack can be performed.

As described above, since the coating evaluation method according to the present invention evaluates the coating strength by giving an impact force, it is a destructive test, but can quantitatively evaluate the weakest portions of the coating and the substrate. Further, if the present invention is applied to a coating actually used, the degree of damage of the coating can be evaluated from the amount of peeling of the coating. Furthermore, relative evaluation can be performed by giving a constant impact force to the evaluation of the coating material and the workability.

As a result, the absolute value of the impact resistance of each coating can be obtained, and conversely, the allowable impact force in actual use, that is, the size and speed of the foreign matter in the case of foreign matter collision are regulated. A reference is obtained.

[0034]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram of a processing procedure showing a first embodiment for explaining a coating strength evaluation method according to the present invention.

In this embodiment, first, a coating sample to be evaluated is prepared (S1). Coating samples were partially stabilized zirconia containing 8% (5-15% range) yttria in the top coat, and NiC in the bond coat.
oCrAlY. The coating sample was used for coating or testing in a state where the sample was applied to the gas turbine component, and small balls were caused to collide with these samples under certain collision conditions (S2). This test is preferably performed several times at different collision speeds.

Next, the coating peeling amount of the sample with which the small ball has collided is measured (S3), and the limit energy at which the peeling becomes zero is obtained from the relationship between the peeling amount and the collision energy or the collision speed of the small ball (S4). The degree of damage (S6) and the strength (S7) are evaluated from the change in the limit energy.

Alternatively, the evaluation can be made by comparing the amount of peeling caused by a constant impact energy from the curve itself.

FIG. 2 is a cross-sectional view showing an example of the configuration of a small ball collision test apparatus used in the above-described processing procedure S2.

In FIG. 2, a small ball 3 for colliding with the coating is disposed in front of a carrier called a sabot 2 placed behind the barrel 1, and a mechanism for sending out a certain amount of gas such as air from behind the barrel 1. By this gas pressure, the small ball 3 and the sabo 2 are united to form a barrel 1
Glide inside and accelerate. At the muzzle portion, which is the exit of the barrel 1, a speed detector 4 for optically detecting the speed of the small ball 3 is provided, and the speed of the small ball is measured at this portion. Barrel 1
A stopper 5 for stopping only the sabo 2 is provided at the tip of the.

The stopper 5 is made of a flexible material whose inner diameter is slightly smaller than that of the barrel. When the stopper 5 comes into strong contact with the sabo 2, the sabo 2 stops and only the small ball 3 is coated. This impinges on the sample 6.

In order to perform the test in a high temperature or special atmosphere, only the coating sample 6 is placed in these environmental chambers 7, and the shutter 8 provided between the environmental chamber 7 and the muzzle is opened only at the moment of the test. As a result, a test in the environmental tank 7 becomes possible.

As shown in FIG. 3, the shutter 8 operates in conjunction with a switch for starting the test (S11). When the environmental tank 7 is used, the shutter 8 is opened (S12) before the gas is introduced by opening the valve and its confirmation operation is performed. (S13), and after a certain time after the gas inflow (S14), the shutter 8 is closed (S1).
5) to do so. For this reason, the test can be performed with little disturbance in the test environment in the environment tank.

Next, the amount of peeling of the coating on the sample 6 that has collided is measured in the processing step S3, which is performed nondestructively using infrared rays or ultrasonic waves.

FIG. 4 is a diagram showing a system for measuring the amount of peeling using infrared rays.

Since the peeling of the coating caused by the collision of the small balls occurs between the coating and the substrate or the bond coat as the intermediate layer, it cannot be usually measured by visual observation.

Therefore, in the measuring system using infrared rays shown in FIG. 4, the sample 6 which has been internally peeled is irradiated with infrared rays by using an infrared lamp 11 and an infrared camera 12 to heat the surface, and the peeled part and the peeled part are separated. The amount of peeling is detected from the difference in the temperature rise of the part where no peeling is performed.
That is, when a certain amount of heat is applied to the peeled part, the peeled part becomes a heat insulating layer of air and the amount of heat transmitted to the base material decreases. More heat is transmitted to the material, and the temperature rise is reduced. Therefore, by measuring the temperature distribution at the time of heating and at the time of cooling, the peeling state is visualized. The peel amount is expressed as a peel area or a peel diameter (length) from an image taken by the infrared camera 12.

FIG. 5 is a diagram of a detection system for detecting the amount of peeling using ultrasonic waves.

As shown in FIG. 5, the ultrasonic wave transmitted from the transmitting section 21 is amplified by the transmitting section 22, and the ultrasonic wave is transmitted from the sensor 23 provided in contact with the surface of the coating sample 5. Since the ultrasonic wave is reflected at the discontinuous portion of the material, the difference between the reflected wave of the portion continuous with the base material and the portion of the discontinuous portion due to separation is captured by the receiving unit 24, and this waveform is captured by the amplifying unit 25. Amplify the signal and send it to the transmitting unit 21 at the analyzing unit 26.
By comparing with the transmitted ultrasonic waveform, the magnitude of the separation can be analyzed.

The amount of separation measured in this manner is expressed as shown in FIG. 6 when it is associated with the collision energy or the collision speed of the small ball in the processing procedure S4.

As shown in FIG. 6, when the test is performed several times while changing the collision speed of the small ball to obtain the relationship between the measured value of the amount of separation and the collision energy, a curve on the upper right is obtained.
In this curve, the collision energy at which the separation amount becomes 0 is obtained in the processing procedure S5. Then, in the processing steps S6 and S7, the degree of damage and the strength of the coating are evaluated based on the change in the limit energy.

Alternatively, the degree of damage or the strength of the coating can be evaluated by comparing the amount of peeling caused by a constant impact energy from the curve itself.

Further, the size of the flying object that can be allowed to collide in the environment in which the coating is used can be specified from the limit energy. In this case, the amount of separation is not determined only by the collision energy of the flying object, but the collision cross-sectional area of the flying object is also an important factor. Even if the collision energy is small, the amount of separation increases when the collision cross section is small.

FIG. 7 shows the relationship between the impact energy and the peeling amount using the value obtained by dividing the impact energy by the collision cross-sectional area as a parameter. Since the two have an integral relationship irrespective of the diameter of the flying object, the limit condition, that is, the allowable size of the foreign object can be defined using this relationship.

FIG. 8 is a graph showing the results of a test performed while changing the collision angle. The collision angle can be changed by changing the setting angle of the coating sample. Regarding the collision angle, the condition of a collision accuracy of 90 ° in which the collision is perpendicular to the coating surface has the largest peeling damage. This can be achieved by comparing the limit energy at which separation starts and the amount of separation at the same collision energy. Therefore, in comparison of actual coated parts, it is necessary that the collision angle is always the same.

FIG. 9 is a graph showing a comparison of test results between room temperature and high temperature. Although there is no significant difference between the two, the limit energy is smaller in the room temperature test, and the amount of separation is larger for the same collision energy. For this reason, in the comparison of coated parts, delamination at room temperature, where the ductility of the material decreases, rather than at the high temperature, which is the operating temperature, is clearly apparent.

As described above, the condition at a collision angle of 90 ° at room temperature can be set as a standard test condition for clearing the peeling characteristics.

FIG. 10 is a graph showing a comparison between a material damaged by thermal fatigue and the like and an unused material. Since the damaged coating member has a small crack inside, the amount of peeling for the limit energy and the same impact energy increases.

Accordingly, by obtaining the relationship between the damage amount and the limit energy or the peel amount as a master curve, the damage amount can be evaluated from the limit energy or the peel amount.

FIG. 11 shows an example. When the coating material that has been used over time and has been damaged is evaluated using the critical energy when not used and the peeling amount against the reference collision energy as the initial value, the critical energy and the peeling amount change from the initial values. Can be used to evaluate the degree of damage to the coating member. Further, a future inspection time can be set from the result and the use time, and the remaining life can be estimated.

Further, the size of the projectile that can be allowed to collide in the environment in which the coating is used can be specified from the limit energy. In this case, even when the collision energy is small, the separation amount is large when the collision cross section is small. Therefore, as shown in FIG. Evaluate energy. Since the collision velocity of the flying object foreign matter on the coated part is determined by fluid analysis, the limit condition, that is, the allowable size of the flying object foreign matter can be defined using this relationship as shown in FIG.

As described above, in the first embodiment of the present invention, as a method for evaluating the degree of damage or the strength of the coating, a local destruction test by small ball collision is used. This test can be easily performed on real parts such as coated rotor blades.

In a normal tensile test or an adhesion strength test, a test piece needs to be mounted on a testing machine via a jig, so that the shape in which the test can be performed is considerably limited. Was almost impossible to measure.

However, in this embodiment, the setting is completed only by placing the component to be evaluated at the muzzle portion where the small ball comes out. Evaluation in a high-temperature environment or a special atmosphere can be easily performed by attaching a shutter to an environmental tank and linking it with a tester.

If the impact energy is used as a reference in the test, the adhesion strength and the damage degree of the coating can be evaluated by evaluating the amount of peeling by at least one evaluation test. Further, if the test is performed several times, the evaluation based on the limit energy becomes possible, so that the evaluation accuracy of the strength and the degree of damage can be improved.

In these evaluation tests, the coating of the actual part is peeled off as a result. However, by performing re-coating on this peeled part, it is possible to easily restore the unused state. The parts to be tested can be used in many tests as sampling inspection test pieces representing the whole parts. For this reason, a change in the degree of damage over time can be confirmed on the spot, so that a temporal change in future coating damage can be quickly captured and directly reflected in a future inspection interval or operation form.

Further, an evaluation method necessary for evaluating the adhesion strength and impact resistance of the coating, which is indispensable in the development of the material of the thermal barrier coating and the application method, and a rotating device necessary for operating the gas turbine. The allowable size of the inflowable foreign matter can also be set.

As described above, since the strength and the degree of damage of the coating can be easily evaluated, the blade structure has a great effect in the deterioration of the coating in the actual part and the development of the material of the coating.

In the first embodiment, a collision test, which is a destructive test, is performed to evaluate the amount of peeling. However, the present invention can be evaluated by analysis.

FIG. 13 is a schematic view showing a second embodiment for explaining the method of evaluating the coating strength according to the present invention.

In the second embodiment, as shown in FIG. 13, a model is created by using elements of a base material 31, a bond coat 32, and a top coat 33 which constitute a coating sample.
The small ball 34 is caused to collide with the model at the speed actually performed in the collision test. When the strain generated in the coating is sequentially determined after the collision, a large strain is generated in the boundary layer 35 between the top coat 33 and the bond coat 32 as shown in FIG.

As for this strain, the shear strain has a large ratio, and the relationship between the shear strain and the amount of peeling is small ball 34.
Are constant as shown in FIG.

Therefore, in the present invention, this analysis can be applied as a substitute for the small ball collision test. Furthermore, when a boundary layer 35 element was provided at the boundary between the top coat 33 and the bond coat 32 and this element was given a function of disappearing when a certain critical strain was reached, an actual peel crack was reproduced as shown in FIG. Cracks can occur. At this time, the critical strain can be given under the condition that an analysis corresponding to a collision test is performed and an actual peel amount is generated.

Further, instead of applying an impact force, a coating is generated by applying a static load, and the degree of damage and adhesion strength of the coating can be evaluated from the relationship between the applied load and the amount of peeling. That is, as shown in FIG. 16, an evaluation simulating a collision test can be performed by applying a static load to the coated sample via the small ball 34.

In this case, for the correspondence between the impact energy and the magnitude of the static load, a calibration curve serving as a master curve is created in advance, and the impact energy is evaluated using this. In addition, by performing the finite element analysis corresponding to the static load described above, the magnitude of the shear strain and the separation crack can be reproduced in the same manner as in the impact analysis, so that the evaluation by the static load analysis can be performed. .

As described above, in the evaluation by the analysis of the small ball collision according to the second embodiment of the present invention, the strength and the degree of damage can be evaluated without using any actual parts or test pieces. If the basic strength is known, it is a very effective evaluation method without damaging the actual parts.

Further, in the second embodiment, since the evaluation is made by the strength test under the impact load, the result can be directly reflected in the allowable standard for the collision of the flying object during operation. With respect to this allowable criterion, it is possible to define the result of the small ball collision test by reflecting the impact energy and the size of the flying foreign matter in the actual collision conditions.

As described above, the method for evaluating the strength of a coating according to the present invention can easily evaluate the strength of a coating applied to an actual part having a complicated shape such as a moving blade. In addition, it is possible to improve the estimation accuracy by conducting multiple tests, and to take measures such as replacing parts and re-coating in consideration of the expected regular inspection interval in the damage evaluation of actual parts. .

Further, in the second embodiment of the present invention,
Since the evaluation of the coating by the static load is given instead of the impact load, if the test piece or the static load test can be easily installed, the evaluation can be made by this method. Since the static load can be evaluated by a conventional general-purpose load test apparatus, the test is further facilitated. In this method, the result of the static load test can be reflected to the standard of the allowable flying foreign matter diameter by clarifying the correspondence between the impact energy and the static load.

The present invention is not limited to the above-described embodiment. The method for evaluating the strength of a coating is not limited to a top coat which causes peeling, but also a bond coat or a substrate itself used for bonding with a substrate. It can also be applied to the evaluation of In this method, by selecting a material that needs to be evaluated and manufacturing other parts except for this part with the same material, the degree of influence of the material that needs to be evaluated can be checked.

As described above, by examining the influence of the bond coat and the base material on the peel strength, it is possible to improve the strength of the entire coating and promote the material development.

[0082]

As described above, according to the coating strength evaluation method of the present invention, the strength of the applied coating can be easily evaluated even for an actual part having a complicated shape. By performing multiple tests, the estimation accuracy can be improved, and in the damage evaluation of actual components, measures such as component replacement and re-coating can be formulated in consideration of the expected regular inspection intervals.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a processing procedure showing a first embodiment for explaining a method of evaluating coating strength according to the present invention.

FIG. 2 is a sectional view showing a configuration example of a small ball collision test apparatus used in the embodiment.

FIG. 3 is a flowchart for explaining the operation of the shutter from the start to the end of the test in the small ball collision test apparatus.

FIG. 4 is a system diagram in the case where the amount of peeling of the coating is measured by infrared rays in the embodiment.

FIG. 5 is a system diagram in the case of measuring the amount of peeling of the coating by ultrasonic waves in the embodiment.

FIG. 6 is a graph showing a relationship between a measured value of a peeling amount and collision energy in the embodiment.

FIG. 7 is a graph showing the relationship between the amount of separation and the value obtained by dividing the impact energy by the collision cross-sectional area.

FIG. 8 is a graph showing the results of a test performed by changing the collision angle.

FIG. 9 is a graph showing a comparison of test results between room temperature and high temperature.

FIG. 10 is a graph showing a comparison between a material damaged by thermal fatigue and the like and an unused material.

FIG. 11 is a graph showing an example of evaluating a damage amount from a limit energy and a peel amount in the embodiment.

FIG. 12 is a graph showing a relationship between a flying object foreign matter diameter and a collision measure in the embodiment.

FIG. 13 is a schematic view showing a second embodiment for describing a method for evaluating coating strength according to the present invention.

FIG. 14 is a graph showing a relationship between a shear strain and an amount of peeling in the embodiment.

FIG. 15 is a schematic diagram showing a state in which an actual peeling crack is reproduced in the embodiment.

FIG. 16 is a schematic diagram showing a state in which a collision test is simulated by applying a static load to the coated sample via small balls in the same embodiment.

FIG. 17 is a schematic diagram showing a state in which a large strain is generated in a boundary layer between the top coat and the bond coat in the embodiment.

FIG. 18 is a diagram for explaining a change in temperature depending on the presence or absence of a coating.

FIG. 19 is a diagram for explaining a general coating damage mode.

FIG. 20 is a sectional view showing a configuration of a main part of the gas turbine.

[Explanation of symbols]

 1: Barrel 2: Sabo 3: Small ball 4: Speed detector 5: Stopper 6: Coating sample 7: Environmental tank 8: Shutter 11: Infrared lamp 12: Infrared camera 21: Transmitting unit 22: Transmitting unit 23: Sensor 24: Receiving unit 25: Amplifying unit 26: Analyzing unit 31: Base material 32: Bond coat 33: Top coat 34: Small ball 35: Boundary layer

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takahiro Kubo 2-4, Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture F-term in Toshiba Keihin Works (reference) 2G040 AA07 AB08 BA14 BA26 CA02 CA12 CA23 DA06 DA12 EA06 EB02 HA02 HA14 2G047 AA09 AC06 BA03 BC03 BC09 CA01 EA10 EA11 GG27

Claims (12)

[Claims] 1. A method for evaluating the adhesion strength of a coating applied to a surface of a member, wherein a sphere is made to collide with the coating, and the amount of peeling damage of the coating is measured to evaluate the strength of the coating. Coating strength evaluation method. 2. The coating strength evaluation method according to claim 1, wherein the surface of the member is irradiated with infrared rays when the amount of peeling damage of the coating is non-destructively measured.
A coating strength evaluation method characterized by evaluating a difference in temperature rise between a peeled portion and a non-peeled portion. 3. The coating strength evaluation method according to claim 1, wherein, when non-destructively measuring the amount of peeling damage of the coating, the surface of the member is irradiated with ultrasonic waves, and reflection at the peeled portion and the non-peeled portion is performed. A coating strength evaluation method characterized by evaluating an amount of peeling based on a difference in waves. 4. The coating strength evaluation method according to claim 1, wherein the strength of the coating is evaluated by an amount obtained by dividing the amount of delamination damage by the impact energy of the sphere by the collision sectional area. Method. 5. The coating strength evaluation method according to claim 1, wherein, when measuring the amount of peeling damage of the coating, an environmental tank containing the member in a special atmosphere, a barrel firing the sphere, and A coating strength evaluation method, comprising: a shutter provided between a muzzle part of a barrel and the environmental tank and opened only when the sphere passes, and performing a test without disturbing the atmosphere of the environmental tank. 6. The coating strength evaluation method according to claim 1, wherein the coating strength is determined based on the amount of peeling damage and the collision speed or impact when the coating is impacted a plurality of times with a sphere having the same diameter while changing the impact speed. A coating strength evaluation method characterized in that the evaluation is made by obtaining a limit collision speed that causes damage from the relation of energy. 7. The coating strength evaluation method according to claim 1, wherein the strength of the coating is evaluated based on a limit impact energy for a mechanical damage or a small crack due to thermal fatigue generated at an interface of the coating. Coating strength evaluation method. 8. The coating strength evaluation method according to claim 1, wherein the strength of the coating is evaluated by a mechanical damage due to thermal fatigue generated at an interface of the coating or a peeling amount with respect to an impact energy based on a minute crack. The method for evaluating coating strength according to claim 1, wherein: 9. A method for evaluating the adhesion strength of a coating applied to a surface of a member, wherein the material characteristics of each part of the coating are known, and damage due to collision of a sphere is evaluated by finite element analysis. Evaluation method. 10. The coating strength evaluation method according to claim 9, wherein, when evaluating damage due to collision of a sphere by finite element analysis, a peeling region is obtained from a spread of a fixed amount of shear strain generated at a coating interface. Coating strength evaluation method. 11. The coating strength evaluation method according to claim 9, wherein when the damage due to collision of the sphere is evaluated by finite element analysis, the element disappears when a predetermined amount of strain is reached in a portion of the coating where a peeling crack occurs. And a method of evaluating a coating strength, wherein a peeling crack generated at a coating interface is reproduced. 12. A method for evaluating the adhesion strength of a coating applied to the surface of a member, wherein the material properties of each part of the coating are known, and the amount of peeling damage is determined by a static load test or finite element analysis. A coating strength evaluation method characterized by evaluating the following.