JP3670869B2 - Coating layer thermal resistance measurement method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for measuring a change in thermal resistance due to deterioration of a coating layer applied to a substrate. More specifically, the present invention obtains a thermal resistance in a non-contact manner without destroying a coating layer and a substrate such as an inner wall to which the coating layer is applied, particularly in the interior of a gas turbine combustor. It relates to the improvement of the evaluation method.
[0002]
[Prior art]
In gas turbines where the combustion gas temperature is increasing for higher efficiency, thermal barrier coating (also called TBC for short) that protects the base material of high-temperature components from high-temperature gas is an indispensable technology. For example, it is applied to a gas turbine combustor, a first stage stationary blade, a first stage moving blade, and the like.
[0003]
In the coating layer applied to the base material surface of such high-temperature parts, cracks, thinning, densification, peeling, etc. occur as the operation time becomes longer, and the heat shielding performance gradually increases because heat is easily transmitted. It will decline. For this reason, it is necessary to regularly inspect and maintain the coating layer to prevent it from falling below a predetermined heat shielding performance.
[0004]
Here, since the thermal insulation performance corresponds to the thermal resistance of the coating layer, a non-destructive inspection method for the amount of scale adhering to the inner surface of the boiler tube proposed as a thermal resistance measurement method (Japanese Patent Laid-Open No. 54-107400). And Japanese Patent Application Laid-Open No. 2-126145). However, since these are intended to detect the scale attached to the back side of the measurement surface, they are not necessarily reliable inspection methods, and there is a problem with inspection accuracy.
[0005]
On the other hand, the measurement by the eddy current flaw detection method and the ultrasonic flaw detection method which detect the thickness change accompanying deterioration of a coating layer is also proposed. However, these only capture the thinning state by visually observing cracks on the coating layer surface by penetrant flaw detection, and it is not possible to grasp the thermal insulation performance decline due to densification, so the temperature of the substrate is increased. It does not quantitatively evaluate the thermal degradation that occurs.
[0006]
In order to solve these problems, a coating layer thermal resistance measurement method, which is one of the nondestructive inspections common to all members having a coating layer, has been proposed. This measurement method is particularly effective for measuring the thermal resistance of a coating layer having a large difference in thermal conductivity from the substrate, such as a thermal barrier coating layer.
[0007]
[Problems to be solved by the invention]
However, in the conventional coating layer thermal resistance measurement method, since the measurement is performed by directly contacting the sensor, it is difficult to evaluate the contact thermal resistance, and there is a problem that the measurement can be accurately performed only on a smooth surface.
[0008]
In addition, the conventional thermal resistance measurement takes a long time to perform steady heating, measures the thermal conductivity when the front and back temperatures are stable, and calculates the thermal resistance using the coating layer thickness data. For this reason, there is a problem that an error occurs when there is a non-uniform portion in the shape to be measured when viewed from the center of heating, and it takes time for measurement.
[0009]
Therefore, at present, the TBC surface is only visually observed for cracking and peeling, and there is no appropriate method for quantitatively evaluating the deterioration state with respect to thinning and densification that cause an increase in the base material temperature. It is in.
[0010]
Accordingly, the present invention provides a coating layer thermal resistance measurement method capable of quantitatively measuring and evaluating deterioration in heat shielding performance due to thinning and densification of the coating layer quantitatively and in a short time by nondestructive measurement. For the purpose.
[0011]
[Means for Solving the Problems]
In order to achieve this object, the invention according to claim 1 measures and evaluates the thermal resistance of the coating layer when the thermal properties of the coating layer applied to the substrate are changed from the reference thermal resistance material. In the coating layer thermal resistance measurement method, obtain the correlation between the thermal resistance of the coating layer and the detection temperature under any measurement heating conditions for the reference thermal resistance material. Surface of The surface temperature of the coating layer at that time was continuously measured, and this measured value was compared with the surface temperature change measured under the same conditions of the reference thermal resistance material. From the difference in surface temperature change, the correlation between the thermal resistance of the coating layer and the detected temperature is used to calculate the amount of change in the thermal resistance of this coating layer, and based on the thermal resistance value of the reference thermal resistance material, The thermal resistance is obtained.
[0012]
That is, in the present invention, the deterioration state of the coating layer as an object is regarded as a thermal resistance change from a thermal viewpoint, and this change is detected at the temperature detected on the surface of the coating layer (this is simply detected in this specification). (Referred to as temperature). That is, here, we focus on the fact that the temperature detected on the surface when the coating layer is heated and the thermal resistance at that time can be expressed as a function with a one-to-one correspondence. The correlation between the two in the reference thermal resistance material is obtained in advance under certain conditions, and then the coating layer that has been used and has reduced thermal insulation performance is heated under the same conditions to detect the surface temperature. ing. In this case, since a functional correlation between the surface detection temperature and the thermal resistance has already been obtained, the thermal resistance of the coating layer corresponding to the detected temperature is indirectly measured by using the detected temperature as a parameter. be able to.
[0013]
In short, in the present invention, in measuring the heat shielding performance of the coating layer, once the correlation between the thermal resistance of the new coating layer material and the detected temperature of the surface is obtained, the temperature detected on the surface is the rest. Therefore, the thermal resistance value possessed at that time can be obtained, so that the thermal resistance of the coating layer can be obtained nondestructively without measuring the thickness and thermal conductivity as in the prior art. In addition, in this measurement method, the measurement object is on the same side as the measurement surface, and a more accurate measurement is possible.
[0014]
Further, the invention according to claim 2 corresponds to the correlation between the thermal resistance of the reference thermal resistance material and the detected temperature and the limit thermal resistance value of the reference thermal resistance material in the coating layer thermal resistance measurement method according to claim 1. Obtain the limit detection temperature to be measured, measure the aged material of the coating layer to correct the correlation between the thermal resistance and the detection temperature, and then compare the detection temperature measured by unsteady heating with the limit detection temperature Thus, it is determined whether or not the thermal resistance of the coating layer is less than the limit thermal resistance value.
[0015]
The correlation between the thermal resistance obtained at the time of new coating layer and the detected temperature may cause an error between the actual correlation and the actual use of the coating layer. Prior to the measurement, the correlation between the thermal resistance and the detected temperature is corrected to eliminate the error, so that a more accurate measurement result can be obtained. In addition, if the limit detection temperature is obtained in advance as in the present invention, whether or not the coating layer has a limit thermal resistance value only by comparing the measured detection temperature and the limit detection temperature, in other words, It can easily be determined whether or not the predetermined thermal resistance is still provided.
[0016]
Furthermore, the invention according to claim 3 is the coating layer thermal resistance measurement method according to claim 1 or 2, wherein the coating layer is heated. From the surface side of the coating layer, The temperature is changed so as not to cause a temperature change on the surface opposite to the coating layer of the substrate. In this case, even if the thickness of the substrate is not constant, it does not affect the detection temperature, so accurate measurement is possible, and continuous heating and temperature measurement are fast and simple, and the measurement target Since the surface and the heating / temperature measuring surface are on the same side, more accurate measurement is possible.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the configuration of the present invention will be described in detail based on an example of an embodiment shown in the drawings.
[0018]
1 to 6 show an embodiment of the coating layer thermal resistance measurement method of the present invention. This coating layer thermal resistance measurement method has a thermal characteristic of the coating layer 2 applied to the substrate 1 (that is, a thermal insulation performance that prevents the substrate 1 from exceeding a predetermined temperature) compared to a reference thermal resistance material. The thermal resistance R of the coating layer 2 when it is changing is measured and evaluated.
[0019]
In the coating layer thermal resistance measurement method of the present embodiment, the heat of the coating layer 2 under the heating conditions for measurement based on the heating test data of the reference thermal resistance material and the unsteady thermal conduction numerical analysis of the coating layer 2. Obtaining the correlation between the resistance R and the detected temperature (surface temperature) T, measuring the change in the surface temperature of the coating layer 2 when the coating layer 2 to be measured for thermal resistance is heated from the coating layer 2 side, This measured value is compared with the change in the surface temperature measured under the same conditions of the reference thermal resistance material, and the difference between the surface temperature changes is used to calculate the correlation between the thermal resistance R of the coating layer 2 and the detected temperature T. The thermal resistance change amount of the coating layer 2 is calculated, and the thermal resistance R of the coating layer 2 can be obtained based on the thermal resistance value of the reference thermal resistance material.
[0020]
The coating layer 2 to be measured in the present embodiment is used to protect the base material 1 of the high-temperature component from the high-temperature gas in the gas turbine combustor 3 or the first stage stationary blade or the first stage moving blade as shown in FIG. It is a thermal barrier coating. In this case, the reference thermal resistance material is generally the coating layer 2 itself used at the time of the new material. However, as long as it becomes a standard for how much the thermal characteristics of the coating layer 2 have changed, the same numerical characteristics can be obtained. New material models and thermal data provided can also be used.
[0021]
Here, how to determine the thermal resistance R of the coating layer 2 provided in the gas turbine combustor 3 or the like will be described. When the thickness of the coating layer 2 is δ and the thermal conductivity is λ, the following It can be obtained from Equation 1.
[0022]
[Expression 1]
R = δ / λ
In addition, when the detection temperature detected on the surface of the coating layer 2 is T, the heat resistance R and the detection temperature T are the base material 1 and the coating layer under the heating conditions in which the heating intensity and the heating time are constant. It has a specific correlation determined by a combination of two. And the thermal resistance R of the coating layer 2 at the time of a measurement can be known by measuring the change of the detection temperature T at the time of heating on fixed conditions.
[0023]
Hereinafter, an embodiment of the present invention will be described in order. According to this coating layer thermal resistance measurement method, the thermal resistance R of the coating layer 2 is obtained through three stages: (1) prior examination, (2) calibration line correction with actual machine aged material, and (3) actual machine measurement.
[0024]
First, the prior study (1) is a stage in which the conditions that serve as a reference for measuring the thermal resistance are examined and determined in advance. The reference condition in this case is the detected temperature T of the coating layer 2 when a new material is used. ₀ , Thermal resistance R ₀ And their correlation. Actually, the detected temperature T when the coating layer 2 in the new material state is first heated at a constant heat flux for a certain period of time. ₀ And the thermal resistance R at this time ₀ Is obtained by design data or actual measurement of the coating layer 2. Thermal resistance R ₀ Is obtained by Equation 1 above, and in this embodiment, the thermal conductivity λ at the time of a new material is obtained. ₀ And coating layer 2 thickness δ ₀ Is calculated by applying to Equation (1). Where thermal conductivity λ ₀ And thickness δ ₀ These physical property values are obtained by actually measuring the actual coating layer 2 at the time of a new material. For example, a value obtained by measuring an actual new material using a microscope is a thickness δ of the coating layer 2. ₀ May be adopted as the actual conductivity of the new material, the value obtained as a result of measuring this by a conventional method is the thermal conductivity λ ₀ May be adopted. As described above, instead of the physical property value of the coating layer 2 itself, the thermal resistance R is obtained by using the physical property value such as thermal data already obtained at the time of the new material. ₀ Can also be requested.
[0025]
The detected temperature T thus obtained ₀ , Thermal resistance R ₀ Are shown as coordinates on the graph representing the relationship between the detected temperature T and the thermal resistance R shown in FIG. And this coordinate (T ₀ , R ₀ ) As a reference, the change in the detected temperature T when the thermal resistance R changes is obtained by numerical analysis (unsteady heat conduction calculation) as coordinates of several points, written on the graph, and then connected to the correlation test Line A is obtained. Therefore, this correlation test line A is represented by the thermal resistance R ₀ And detection temperature T ₀ It will be expressed as a function indicating the correlation. In addition, this correlation can also be calculated | required from the test result using the test piece which changed the thermal resistance R other than numerical analysis.
[0026]
Then, the critical thermal resistance value Rcri of the coating layer 2 is obtained. The critical thermal resistance value Rcri is calculated from the thermal resistance R that the thermal barrier coating layer 2 should always hold in the gas turbine combustor 3 and the like based on various conditions such as the design temperature of the base material 1 and actual machine operating conditions. The This critical thermal resistance value Rcri serves as a guideline indicating how far the coating layer 2 may deteriorate within a range in which the base material 1 does not exceed the limit temperature. There are also cases where a certain margin is set as a guideline for the limit. Then, by taking this limit thermal resistance value Rcri on the previous test line A, the corresponding limit detection temperature Tcri is obtained.
[0027]
Next, the process proceeds to the calibration line correction stage (2). Since the verification line A obtained as described above is not an actual measurement of the aged material of the coating layer, there may be an error from the actual line.
[0028]
Therefore, an actual actual machine aged material (coating layer 2 used in the actual machine and aged) is measured, and a calibration line with the error corrected is created. First of all, the detected temperature T in actual machine aged material ₁ Further, the physical properties of the coating layer 2 (thermal conductivity λ ₁ , Thickness δ ₁ ) And the detected temperature T ₁ And thermal resistance R of coating layer 2 ₁ Is represented on the graph as coordinates, and if this is deviated from the previous test line A (shown by a broken line in the figure) as shown in FIG. ₁ , R ₁ The calibration line is corrected so as to pass through the calibration line B (shown by a solid line in the figure) without error. That is, the verification line B eliminates the error between the calculation verification line (or at the time of initial measurement) and the actual verification line. As a result, the initially obtained limit detection temperature Tcri is also corrected to the correct limit detection temperature Tcri ′ (hereinafter, this corrected limit detection temperature is indicated by Tcri) as shown in FIG. Here, the coordinates of one point (T ₁ , R ₁ However, it is needless to say that the accuracy of the correction is further improved if a plurality of different coordinates are used for correction.
[0029]
Here, for example, the thermal resistance R of the coating layer 2 after a certain period of time under high-temperature oxidation conditions ₁ In the case of measuring, the detected temperature T when heated under the same conditions (heat flux, time) as when the thermal resistance R was measured for a new material ₁ And T from the correlation test line between the detected temperature T and the thermal resistance R ₁ Thermal resistance R ₁ To ask.
[0030]
The above is the stage until the actual machine is measured. Next, the process moves to the stage (3) where the actual machine is actually measured. In this actual machine measurement stage, the deterioration state of the heat shielding performance of the coating layer 2 is evaluated based on the temperature response data when the surface of the coating layer 2 is heated from the coating layer 2 side. In this embodiment, the coating layer 2 is applied to the inner peripheral surface of the cylindrical combustor 3, and the laser beam is locally heated from the coating layer 2 side to the coating layer 2 with a constant heat flux. Heated to such an extent that the temperature change of at least the opposite surface in contact with the coating layer 2 of the substrate 1 does not occur (preferably the temperature of the surface in contact with the coating layer 2 of the substrate 1 does not occur). When the surface temperature of the coating layer 2 is measured (when the unsteady heating method described later) is measured, the deterioration of the coating layer 2 is compared with the temperature change when the same heat flux is applied when the coating layer 2 is in a new material state. And the thermal resistance R of the coating layer 2 having a correlation therewith is measured.
[0031]
Here, as a heating method of the base material 1, the heating region is moved at a constant speed depending on the heating mode, and heating is performed to such an extent that temperature change of at least the opposite surface in contact with the coating layer of the base material does not occur. There are two main types: a non-stationary heating method in which temperature measurement is performed in accordance with the moving heating region, and a quasi-stationary heating method in which temperature measurement is performed in a region heated with a heat source fixed. Further, the quasi-stationary heating method can be divided into a quasi-stationary point heating method in which laser is locally used as a heating source and a quasi-stationary surface heating method in which a relatively wide range is heated by using a lamp or the like as a heating source.
[0032]
In the non-stationary heating method, as shown in FIG. 4, heating is performed so as to continuously scan the surface of the coating layer 2 using a heating source 4 such as a laser, and from the change state of the detected temperature T of the coating layer 2, The amount of change in the thermal resistance R of the coating layer 2 as compared with the new material is obtained. The physical quantities involved in this method are the thermal diffusivity, specific heat, density, thickness δ and time of each component, and the heat of the coating layer 2 based on the detected temperature T and each thermophysical value of the component. The resistance R can be calculated. In actual measurement, it is conceivable to apply a laser as the heating source 4 and a radiation thermometer or an infrared camera as the temperature measuring device 5.
[0033]
An example of a configuration when performing such an unsteady heating method will be described. For example, when the combustor 3 has a cylindrical shape as in the present embodiment, the heating source 4 emits light toward the center of the combustor 3. The mirror 6 is arranged on the extension of the cylindrical axis, and on the irradiation axis, the mirror 6 is disposed inside the combustor 3, and the half mirror 7 is disposed between the heating source 4 and the combustor 3. Are inclined by 45 ° with respect to the irradiation axis. In this case, the half mirror 7 is formed so as to transmit the irradiation light from the heating source 4 side while reflecting the temperature information from the combustor 3 side. Therefore, the light irradiated from the heating source 4 toward the combustor 3 passes through the half mirror 7 and reaches the mirror 6, where it is reflected in a right angle direction and is applied to the coating layer 2 on the inner peripheral surface of the combustor 3. It is vertical. The temperature information of the heated coating layer 2 travels in the reverse direction so far and is reflected by the mirror 6 and further reflected by the half mirror 7 in a right angle direction. At this point, a temperature measuring device 5 is provided, and the surface temperature information of the coating layer 2 finally enters the temperature measuring device 5 and is detected as the temperature of the surface of the coating layer 2.
[0034]
When performing such an unsteady heating method, during the heating, the detected temperature T of the coating layer 2 is measured by continuously heating the combustor 3 while rotating it in the circumferential direction. The measurement is performed while shifting in the direction and rotating in the circumferential direction again. In order to rotate in this way, the combustor 3 is provided with a rotation / movement means (not shown) for rotating the combustor 3 in the circumferential direction and further moving it in the axial direction. In this case, the combustor 3 repeats the movement of making one round in the circumferential direction, moving once in the axial direction and then making another round after moving in the axial direction. For this reason, as the combustor 3 moves, the coating layer 2 on the inner peripheral surface of the combustor 3 is continuously irradiated and heated uniformly, and the irradiation at this time is in contact with at least the coating layer 2 of the substrate 1. Since it is a short time that does not cause a temperature change of the opposite surface, it is hardly affected by the thickness and shape of the substrate 1. In addition, measurement is fast because of continuous heating and temperature measurement. Since the rotation in the circumferential direction and the movement in the axial direction during measurement are caused by a change in the relative position between the combustor 3 and the mirror 6, either or both of the combustor 3 and the mirror 6 are pivoted. For example, a method of heating the mirror 6 while moving the mirror 6 may be employed.
[0035]
The quasi-steady heating method is a method for obtaining the thermal resistance R of the coating layer 2 from the detected temperature T of the coating layer 2 after heating for a certain time with the heating source 4 fixed. The physical quantities involved in this method are the thermal conductivity λ, thickness δ, and time of each component. The configuration for heating by the quasi-stationary heating method is not greatly different from the configuration for irradiation by the above-mentioned non-stationary heating method, and is as shown in FIG. 4, but only one point was measured here. There is a feature in that the measurement is performed while rotating the combustor 3 stepwise, such that the next point is measured by moving in the circumferential direction later. This quasi-stationary heating method can be classified into a quasi-stationary point heating method and a quasi-stationary surface heating method depending on the heating conditions and the heating region. That is, if the light from the heating source 4 is irradiated point by point in the same manner as the above-described unsteady heating method, a quasi-unsteady point heating method as shown in FIG. 4 is obtained, and a larger area is heated at a time for each surface. For example, it becomes a quasi-unsteady surface heating method.
[0036]
Here, the quasi-stationary surface heating method, as shown in FIG. 5, heats the coating layer 2 for each region of a certain area by using a lamp or the like inside the combustor 3 as a heating source 4. Large area information can be captured at once. In this quasi-unsteady surface heating method, the next region is heated and measured by rotating in the circumferential direction or moving in the axial direction after measuring one region. Here, the irradiated region is inclined with respect to the cylindrical axis. The thermal resistance R is measured by reading with the provided infrared camera 5.
[0037]
The above is the classification of the heating conditions when the detection temperature T of the coating layer 2 is obtained. When the actual machine measurement is performed by any of the methods described so far, the detection temperature T obtained by this measurement and the limit detection temperature Tcri Investigate the size relationship. In FIG. 3, if the detected temperature T is larger than the limit detected temperature Tcri, the thermal resistance R in the coating layer 2 exceeds the limit thermal resistance value Rcri from the correspondence relationship in the test line B, and the minimum thermal resistance R is reduced. You can see that they are still ready. It can also be seen how much margin is provided from the difference between the detected temperature T and the limit detected temperature Tcri. In this way, when no problem is detected, data can be recorded as it is and used as a database.
[0038]
On the other hand, if the detection temperature T is lower than the limit detection temperature Tcri, the thermal resistance R is also lower than the limit thermal resistance value Rcri, and the thermal resistance R of the coating layer 2 may not satisfy the standard. Understand. That is, since the required thermal resistance R has not been maintained for the part, a predetermined repair work is necessary. FIG. 6 shows a flow when comparing the detection temperature T and the limit detection temperature Tcri.
[0039]
In the coating layer thermal resistance measurement method of the present embodiment, as described so far, the thermal resistance R is obtained without obtaining the coating layer thickness δ, and therefore, the fine measurement as in measuring a thin film is performed. Therefore, the thermal resistance R is obtained directly. For this reason, detailed measurement is unnecessary, and the measurement itself is simple.
[0040]
In addition, since the unsteady heating method performs heating in such a short time that the detected temperature T does not cause a temperature change on the opposite surface contacting the coating layer 2 of the base material 1, the thickness of the base material 1 Even if is not constant, it does not affect the detected temperature T, so that accurate measurement is possible. Furthermore, according to this measuring method, since the heating and temperature measurement are continuously performed, the measurement is fast, and the measurement target surface and the heating and temperature measurement surface are on the same side, so that a higher accuracy measurement is possible. However, in consideration of measurement accuracy, convenience during field measurements, etc., it is considered preferable to use the unsteady heating method. However, in terms of measurement accuracy, the quasi-stationary point heating method is superior, so these can be used in combination. Most preferred. The quasi-stationary surface heating method can be used satisfactorily under conditions where the substrate thickness is uniform, but there is a problem that correction is required under non-uniform conditions. However, it is an effective measurement method for detection of peeling.
[0041]
Each of the above-described embodiments is an example of a preferred embodiment of the present invention, but is not limited to this, and various modifications can be made without departing from the scope of the present invention. For example, among the heating methods in the above-described embodiment, the unsteady heating method in particular is such that the influence of the shape of the substrate 1 is not affected by performing irradiation within a short time while changing the measurement points one after another. However, this can be performed by another method such as irradiation for a predetermined time without changing the heating point. In other words, in the above-described unsteady heating method or the like, the irradiation time is prevented from becoming longer by changing the measurement points one after another, so an embodiment in which the irradiation is stopped in a short time without changing the place is also considered. .
[0042]
Moreover, although the coating layer 2 to be measured in the present embodiment has been described as a thermal barrier coating applied to the gas turbine combustor 3 or the like, there is no change in principle even in cases other than these, According to this measurement method, it is possible to measure and evaluate the thermal resistance R of various coating layers provided for heat shielding.
[0043]
【The invention's effect】
As is clear from the above description, according to the coating layer thermal resistance measurement method according to claim 1, once the correlation between the thermal resistance of the reference thermal resistance material and the surface detection temperature is obtained, the surface Since the thermal resistance value at that time is obtained from the detected temperature, the change in thermal resistance of the coating layer due to thinning and densification is not destroyed without measuring its thickness and thermal conductivity. Thermal insulation performance can be evaluated by measuring with
[0044]
In addition, in this measurement method, the measurement target surface and the heating / temperature measurement surface are on the same side, so the thermal resistance measurement is quantitative and accurate, and sufficient measurement is possible with a short heating time. Measurement is possible.
[0045]
Further, in the coating layer thermal resistance measurement method according to claim 2, since the coating layer is actually measured after correcting the correlation between the thermal resistance and the detected temperature to eliminate the error, a more accurate measurement result is obtained. be able to. Further, by comparing the detection temperature with the limit detection temperature, it can be immediately determined whether the thermal resistance of the coating layer is greater than the limit thermal resistance value.
[0046]
Furthermore, according to the coating layer thermal resistance measurement method according to claim 3, accurate measurement is possible even if the thickness of the base material is not constant, so that accurate measurement is possible and continuous heating / temperature measurement. Therefore, the measurement is quick and simple, and the measurement target surface and the heating / temperature measurement surface are on the same side, so that measurement with higher accuracy is possible.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a coating layer thermal resistance measurement method of the present invention, and shows a correlation test line A between a detected temperature T and a thermal resistance R obtained in a preliminary examination stage.
FIG. 2 is a diagram showing how the correlation test line A in FIG. 1 is corrected to B;
FIG. 3 is a diagram showing a relationship between a limit thermal resistance value Rcri and a limit detection temperature Tcri on a correlation test line B.
FIG. 4 is a diagram showing an embodiment of a non-stationary heating method and a quasi-unsteady point heating method when carrying out the present invention.
FIG. 5 is a diagram showing an embodiment of a quasi-unsteady surface heating method when carrying out the present invention.
FIG. 6 is a flowchart showing a flow when a detected temperature T is compared with a limit detected temperature Tcri.
[Explanation of symbols]
1 Base material
2 Coating layer
R Thermal resistance
Rcri limit thermal resistance
T Detection temperature
Tcri limit detection temperature

Claims (3)

In the coating layer thermal resistance measurement method for measuring and evaluating the thermal resistance of the coating layer when the thermal properties of the coating layer applied to the substrate are changed from the reference thermal resistance material, the reference thermal resistance material is arbitrarily selected. Correlation between the thermal resistance of the coating layer and the detection temperature under the measurement heating conditions is measured, the coating layer is continuously heated from the surface side of the coating layer, and the change in the surface temperature of the coating layer at that time Is measured continuously, the change of the surface temperature measured under the same condition of the reference thermal resistance material is compared with this measured value, and the correlation between the thermal resistance of the coating layer and the detected temperature is determined from the difference in the temperature change. The amount of change in the thermal resistance of the coating layer is calculated using a coating layer, and the thermal resistance of the coating layer is obtained based on the thermal resistance value of the reference thermal resistance material Resistance measurement method.   A correlation between the thermal resistance of the reference thermal resistance material and the detected temperature and a limit detection temperature corresponding to the limit thermal resistance value of the reference thermal resistance material are obtained, and the aging material of the coating layer is measured to measure the thermal resistance. Whether or not the thermal resistance of the coating layer is less than the critical thermal resistance value by correcting the correlation between the thermal detection temperature and the detected temperature and then comparing the detected temperature measured by unsteady heating with the critical detected temperature. The coating layer thermal resistance measurement method according to claim 1, wherein: 3. The coating according to claim 1, wherein the coating layer is heated to such an extent that a temperature change does not occur from a surface side of the coating layer to an opposite side surface of the substrate in contact with the coating layer. Layer thermal resistance measurement method.

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