JPH0127378B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a method and apparatus for diagnosing damage to structural members used at high temperatures, and relates to a method and apparatus for diagnosing damage to structural members used at high temperatures. The present invention relates to a method and device for diagnosing damage by focusing on deterioration.

[Technical background and problems of the invention]

In general, the various types of equipment that make up power plants and chemical plants are often used at high temperatures for long periods of 10 years or more. In the structural members that make up these thermal devices, slip lines increase and form in the crystal grains of the metal crystals that make up the members due to repeated unsteady operation such as starting and stopping the equipment and load fluctuations, and then slip bands are formed. It is known that microcracks with dimensions on the order of metal grains occur along slip zones. On the other hand, during steady operation, pores are generated at the grain boundaries of the metal crystals that make up the component due to creep, and as these pores connect with each other, microcracks occur, and the damage to the material accumulates. . It is thought that the material is damaged until microcracks occur in this way, and the amount of damage is accumulated within the material. Furthermore, heat-resistant steel with excellent high-temperature strength is used for structural members of equipment used at high temperatures.
The various material properties of heat-resistant steel related to fatigue and creep gradually change simply by being exposed to high temperatures for a long time, and the initial strength properties are gradually lost.

For structural members that are used at high temperatures, the operating conditions of the equipment and the material properties of the members are related.
Until microcracks occur, various types of damage accumulate within the material, and if this damage accumulation is left untreated, cracks will develop and propagate in the component, resulting in fatal and devastating damage to the component. It leads to a big situation. Originally, these high-temperature components were designed and manufactured with a certain margin, but in recent years, for example, those used in thermal power plants that have been in use for a long time have frequently been subjected to unsteady operation such as starting and stopping in response to power demand. The amount of damage may accumulate faster than initially expected. In particular, there is a strong desire to develop a technology that can accurately assess the amount of damage accumulated in structural members of equipment such as thermal power plants that are used at high temperatures for long periods of time, and predict and diagnose the period during which they can be used without any problems. In particular, technology for predicting and diagnosing crack occurrence is extremely important for preventive maintenance of equipment.

However, conventional methods for diagnosing damage to structural members are
It merely predicts the degree of damage and lifespan of structural members from the state quantities of temperature and pressure, which represent the operating conditions of equipment used at high temperatures, and states that express the unique characteristics of the materials that make up structural members and their changes. No consideration was given to quantity. In addition, for thermal equipment that has already been installed and has been in operation for several years, the material properties must have changed from the initial state depending on the past operating mode and history, so it is likely that the material properties will change from the initial state. It is not possible to predict the exact degree of damage or service life of structural members unless the changes in the structural components are quantitatively calculated and corrected.

[Purpose of the invention]

Therefore, the purpose of the present invention is to solve these conventionally unresolved problems, and to develop a usage state quantity that represents the usage state of structural members used at high temperatures, and the hardness of the materials that make up the structural members and their changes. Damage to structural members used at high temperatures that allows for accurate understanding of the amount of damage accumulated until cracks occur in structural members, taking into account the state of the material and the operating history of the equipment that uses the structural members. The object of the present invention is to provide a diagnostic method and a device for the same.

[Summary of the invention]

In order to achieve the above object, the present invention detects usage state quantities representing the usage state of a structural member used at high temperatures, calculates the temperature and acting stress of the structural member, and also calculates the hardness and stress of the structural member. The material properties related to damage accumulation are calculated by measuring the material state quantities that represent changes, and the accumulation of damage amounts due to the operating history and operating conditions during the period from the start of equipment operation until the installation of this device is performed. Set all the parameters necessary for the calculation, calculate the amount of damage by adding the amount of damage sustained by the structural member as a correction amount according to the operating history of the equipment, and compare the result with the allowable value to determine the amount of damage to the structural member. It is possible to predict and diagnose the period until cracks occur inside.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a method and apparatus for diagnosing damage to structural members used at high temperatures according to the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the principle of the method for diagnosing damage to structural members according to the present invention. Reference numeral 1 indicates a detection device, and this detection device 1 detects the high-temperature fluid temperature, which is a state quantity in use of the high-temperature member. , is a detection device for high temperature fluid pressure, member temperature, rotation speed, load, and vibration, and is actually one of thermocouples, pressure gauges, and tachometers.
One or more are used. Code 2 is temperature.
A stress calculator is shown, which calculates the temperature and acting stress of the member to be diagnosed for damage from the usage state quantities detected by the detection device 1.

Reference numeral 3 indicates a hardness measuring device, and a required number of hardness measuring devices are set at the measurement location of the device.

Reference numeral 4 indicates a material property calculator, which calculates the material properties at the time of measurement based on the above hardness measurement results.The material properties include tensile properties (tensile strength, yield strength), low cycle fatigue properties. (strain-failure frequency relational expression) and creep-rupture characteristics (stress-temperature rupture time parameter relational expression).

The outputs of the temperature stress calculator 2 and material property calculator 4 are applied to a damage calculator 5, which calculates the amount of fatigue damage due to repeated unsteady operation and the amount of creep damage due to continued steady operation. Calculate.

The outputs of the temperature stress calculator 2 and material property calculator 4 are also applied to a tolerance calculator 6, which calculates tolerances for the accumulation of applied stress and damage amount. The allowable stress value, which is the allowable value for the applied stress, is calculated by setting an appropriate safety factor based on the tensile strength, yield strength, creep rupture strength, and fatigue strength among the outputs of the material property calculator 4. A crack initiation limit damage value, which is a tolerance value for the accumulation of fatigue/creep damage amount and fatigue creep combined damage amount, is set in advance in the tolerance value calculator 6.

Reference numeral 7 indicates a diagnostic device, and the diagnostic device 7 is a device that compares the outputs of the damage calculator 5 and the allowable value calculator 6 to perform predictive diagnosis of the period until a crack occurs in the structural member. The results are transmitted to the display/warning device 8, which displays the diagnostic results or issues a necessary warning depending on the output of the diagnostic device 7.

By the way, if each of the devices from the detection device 1 to the display/alarm device 8 described above is installed on a structural member of a thermal device that has already been installed and is in operation, it is of course possible to collect data after installation, but it is possible to collect data from before installation. Data cannot be collected. For this reason, highly accurate damage diagnosis will not be possible unless the accumulated amount of damage inflicted on the structural member before installation remains unknown and corrections are made accordingly. Therefore, in the present invention, a condition setting device 9 is provided to accurately grasp the amount of accumulated damage by correcting the accumulated amount of damage before installation of the equipment. This condition setter 9 is used to calculate the operating history of the equipment before installation of the device of the present invention, the temperature stress state in typical operating patterns, the number of unsteady operations, the amount of damage accumulated such as steady operation time, etc. This is for setting all parameters. In addition, the condition setter 9 also stores parameters necessary for calculating the amount of damage, such as expected operating history, temperature and stress conditions in typical operating patterns, the number of unsteady operations, and steady operation time. damage calculator 5 through these parameters.
It is possible to calculate all of the damage amount accumulation state before the installation of the device of the present invention, the damage amount accumulation state during actual operation after installation, and the damage amount accumulation state in the operation history expected in the future. Therefore, the diagnostic device 7 can appropriately predict and diagnose the period during which the structural member can be used without any trouble.

In order to accurately calculate the temperature and stress in the actual operating state, it is desirable to use the detector 1 to detect the usage state, but depending on the structure, it may be difficult to install the detector 1 due to the complexity of the shape, etc. Alternatively, there is a concern that the installation may have an adverse effect on structural members, such as stress concentration. Therefore,
In such a case, the condition setting unit 9, which sets all the parameters necessary for calculating the accumulation of damage amount, may be used instead.

Next, a description will be given of an embodiment in which the present invention is applied to a damage diagnosis device for a high temperature part casing of a steam turbine.

Figure 2 shows a cross-sectional view of a high and intermediate pressure steam turbine.
Inside the outer casing 11 is a first inner casing 1.
2 and a second inner casing 13 are spaced apart from each other in the axial direction. In addition, both inner casings 1
A rotor 14 is inserted into the insides of the rotors 2 and 13, and gland packing heads 15 and 16 provided at both ends of the outer casing 11 and the first inner casing 1
Gland packing head 1 provided at one end of 2
7 to prevent steam leakage along the rotor 14.

Thus, high-temperature, high-pressure steam is supplied from the steam supply port 18 to the nozzle box 20 within the first inner casing 12 via the expandable and retractable communication pipe 19. From there, the steam becomes a high-speed flow and hits the blade 21 installed in the rotor 14, imparting kinetic energy to the rotor 14, and then passes through the nozzle in the nozzle diaphragm 22 again, becoming a high-speed flow and hitting the next blade. In this way, the pressure and temperature of the steam decrease each time it passes successively through the blades and nozzles, and it reaches the high-pressure turbine outlet 23, where it reaches 1/2 of the steam supply port 18.
The pressure will be about 4 to 1/8. High pressure turbine outlet 2
The steam No. 3 is once led outside from the steam turbine outlet 23, is reheated through a reheater (not shown) of the boiler, becomes high-temperature steam again, and is supplied to the intermediate pressure turbine inlet section 24. Then, the steam supplied to the intermediate pressure turbine inlet section 24 passes through the nozzle and blades again, imparts rotational energy to the rotor 14, and is discharged from the intermediate pressure turbine outlet section 25.

During operation of the turbine, the outer casing 11, the first
Inner casing 12 and second inner casing 1
3 is turned into high-temperature steam by high-temperature, high-pressure steam and is subjected to internal pressure stress. In addition, during unsteady operation such as starting and stopping the turbine, unsteady thermal stress occurs due to the temperature difference between the inner and outer surfaces of each casing 11, 12, 13, and during steady operation, steady thermal stress occurs due to the temperature difference in the longitudinal direction of the casing. occurs. In particular, high stress is likely to occur in parts with complicated shapes, such as the main steam pipe root 29. As described above, damage due to creep and fatigue accumulates in the high-medium pressure casing due to continuous steady operation and repeated unsteady operation. At the same time, during long-term use at high temperatures, material properties change, accelerating the accumulation of the damage described above.

When the present invention is applied to the diagnosis of the turbine high-temperature part casing configured as described above, the detection of the usage state quantity of the casing and the measurement of the material state quantity, which are the basis of the predictive diagnosis, are performed as follows. The operating state quantities of the casing are main steam temperature, main steam pressure, and casing inner surface temperature, and these are continuously measured by a pressure gauge 30 and a thermometer 31 embedded in the casing as shown in Fig. 2. These detection results are used to calculate the casing temperature and stress.

On the other hand, the material state quantity of the casing is hardness, which is measured when the turbine is stopped. Specifically, as shown in Fig. 3, it is measured by inserting a hardness meter 34 into the part to be measured. and measure it. The measurement position is the casing flange 32, which is a high-temperature, low-stress area, and the flange 32 of the internal casing 12 is particularly selected. The hardness gauge 34 is inserted through the measurement hole 33 provided in the outer casing 11, and the hardness gauge 34 transmits the pressure 35 to the hydraulic pipe 36.
It is configured so that it can be pressed against the measurement surface with a constant pressure, and the displacement at this time can be converted into an electric signal 38 by a differential transformer 37, and further converted into hardness by a calculation device 39. Note that during turbine operation, the measurement hole 33 may be sealed with a plug. Based on the hardness measurement results, material properties and tolerances required for damage calculation are calculated as described later.

Next, a fourth method and device for predicting the period during which the casing can be used without any trouble will be described based on the detection results of the usage state quantities and the measurement results of the hardness.
This will be explained with reference to the figures.

In FIG. 4, the main steam pressure 40, which is the operating state quantity detected by the pressure gauge 30, is expressed by the internal pressure stress calculator 4.
1, it is converted into internal pressure stress. The stress distribution of a structure with a complex shape such as a casing can be determined by photoelasticity or the finite element method, and the internal pressure stress calculator 41 calculates coefficients of stress in each part relative to the reference pressure based on the calculation results. is memorized. Therefore, by multiplying the detected value of the main steam pressure 40 by a coefficient, the internal pressure stress of each part can be immediately calculated.

Next, the main steam temperature or casing inner and outer metal temperatures 42, which are operating state quantities detected by the thermometer (thermocouple) 31, are input to the temperature calculator 43 and the thermal stress calculator 43', and the thermal stress is calculated. used for. The main steam temperature 42 is used together with the main steam pressure 40 to estimate the inner surface metal temperature of the inner casing 12, but this estimation is not necessary if the metal temperature near the inner surface can be directly measured.

From these temperature detection results, the casing temperature,
The stress is calculated by the temperature calculator 43 and the thermal stress calculator 43'.
is calculated as follows.

First, assuming that the casing is a hollow cylinder, the temperature distribution is calculated by solving the differential equation of heat conduction shown in equation (1) based on the time change of the metal temperature 42 on the inner and outer surfaces of the casing.

∂θ/∂ _t =λ(∂ ² θ/∂ _r ² +1/r ∂θ/∂ _r )
...(1) Here, λ: thermal conductivity, θ: temperature, t: time, r: radius Equation (1) can be solved by numerical calculation using the difference method. This results in the volume average temperature Tave, the inner surface temperature
The Ti and outer surface temperatures To are determined, and the thermal stresses σ _i and σ _p on the inner and outer surfaces are determined from equations (2) and (3).

σ _i = Eα/1−ν (Tave−T _i ) …(2) σ _p = Eα/1−ν (Tave−T _p ) …(3) where, E: Young’s modulus, ν: Poisson’s ratio , α: Linear expansion coefficient σ _i and σ _p determined in this way are converted into local stress according to the shape of the casing based on the finite element method analysis. In the predetermined element method, the thermal stress of each part is calculated under a constant temperature increase condition that serves as a standard, and the stress concentration coefficient K _t is determined. The thermal stress calculator 43' calculates the local stress by multiplying the inner and outer surface stresses σ _i and σ _p by the stress concentration coefficient K _T .

The stress adder 44 adds the output of the internal pressure stress calculator 41 and the output of the thermal stress calculator 43' to calculate the combined stress of each part of the inner and outer surfaces of the casing.

Next, the material property calculator 46 calculates the casing using the hardness 45 of high-temperature, low-stress areas, such as the flange portion 32, which is the material state quantity of the casing measured by the hardness meter 34, which is the most important feature of the present invention. Tensile properties during hardness measurement, low cycle fatigue properties,
We will explain the calculation of material properties for calculating the amount of damage accumulated in response to crack occurrence, such as creep rapture characteristics, and the allowable value of acting stress.

FIG. 5 shows the functional procedure of the material property calculator 46 for the tensile property calculation part, and the relationship between hardness and yield strength σ _ys or tensile strength σ _B is expressed by the following equation with temperature as a parameter. There is a relationship.

σ _ys = f ₁ (temperature, hardness) ……(4) σ _B = f ₂ (temperature, hardness) ……(5) Equations (4) and (5) take hardness as Bitkers hardness H _v , When temperature is T, it can be written in the following form.

σ _ys = C _p1 (T) H _v + D _p1 (T) ...(6) σ _B = C _p2 (T) H _v + D _p2 (T) ... (7) Delay, C _p1 (T), C _p2 (T), D _p1 (T), D _p2 (T
)
is expressed as a linear expression or a polynomial of higher order regarding the temperature T. 2 in Fig. 5 is an illustration of equations (6) and (7), and in Fig. 1 the relationship between σ, σ _B , σ _ys and H _v in Fig. 5, when temperature T ₁ < T ₂ < T ₃ It shows that the temperature is higher in order.

The material property calculator 46 gives proof stress σ _ys and tensile strength σ _B as a function of temperature from the hardness measurement results and equations (6) and (7).

Next, FIG. 6 shows the functional procedure of the material property calculator 46 for the low cycle fatigue property calculation part, and as shown in 1 in FIG. 6, the elastic strain range △
There is a relationship between ε _e and hardness expressed by the following equation with the number of repeated failures as a parameter.

△ε _e = f ₃ (hardness, N _f )...(8) Equation (8) can be written in the following form, taking the hardness as the Bitkers hardness H _v .

△ε _e = C _f1 (H _v ) N _f ^Df1(Hv) ……(9) However, C _f1 (H _v ) and D _f1 (H _v ) are the first or higher orders regarding the hardness H _v . Represented by a polynomial.
2 in Figure 6 shows the H _v dependence of C _f1 and D _f1 . Furthermore, the sixth
The relationship between Δε _e and H _v in Figure 1 shows that the number of repeated failures increases in the order of N _f1 < N _f2 < N _f3 .

Furthermore, there is a relationship between the plastic strain range Δε _p and the number of repeated failures N _f as expressed by the following equation: Δε _p = f ₄ (N _f ) = C _f2 N _f ^Df2 (10). C _f2 and D _f2 are constants selected depending on the material.

Combining equations (9) and (10) obtained as above, we get
The relationship between the total strain range △ε _p and the number of repeated failures N _f is (11)
It is expressed by the formula.

△ε _t = △ε _e + △ε _p = C _f1 (H _v ) N _f ^Df1(Hv) + C _f2 N _f ^Df2 ...(11) The material property calculator 46 calculates the formula (11) and the hardness measurement results. From this, calculate the low cycle fatigue characteristics N _f = f ₅ (△ε _t )...(12).

FIG. 7 shows the functional procedure of the material property calculator 46 for calculating the creep rapture properties, and as shown in 1 in FIG. 7, the hardness and absolute temperature T
Larson-Miller parameter P that expresses the relationship between rupture time T _r and rupture time T r P = T (C + log T _r ) (13) Here, C has a relationship with the material constant expressed by the following equation.

P=g ₁ (Hardness) ...(14) Equation (14) takes hardness as Bitkers hardness H _v ,
It can be written in the following form.

P=C _g1 (σ) H _v +D _g1 (σ) ...(15) Here, C _g1 and D _g1 are quadratic polynomials or polynomials of higher order regarding stress σ, as shown by 2 in Figure 7. It is expressed as Note that the relationship diagram 1 between P and _Hv in FIG. 7 shows that the stress increases in the order of σ ₁ <σ ₂ <σ ₃ .

The material property calculator 46 calculates the relationship among temperature, stress, and rupture time from equation (15) and the hardness measurement results.

Based on the measurement of the material state quantities mentioned above, the tensile properties,
By calculating low-cycle fatigue properties and creep-rapture properties, it is possible to quantitatively calculate changes in material properties due to high-temperature long-term use of casings, which had previously been unresolved, and to calculate the amount of accumulated damage with high accuracy. I can do it.

Next, with reference to FIG. 4, calculation of the amount of damage accumulated leading to crack generation will be explained.

The accumulation of fatigue damage, which is one type of damage accumulation due to crack initiation, is due to the repetition of unsteady operation in which stress fluctuates, but the amount of fatigue damage △φ _f accumulated per unsteady operation is Calculated using equation (16).

Δφ _f =1/N _f (16) Here, N _f is the number of repetitions of failure due to repeated stress at the temperature during unsteady operation (low cycle fatigue). Therefore, the amount of fatigue damage Δφ _f accumulated per unsteady operation can be determined by determining the number of repeated failures N _f and calculating the equation (16). In FIG. 4, material property calculator 4
6, as mentioned above, the low cycle fatigue characteristics are calculated from the hardness measurement of the casing flange portion 32 using equation (12), which takes into account changes in characteristics due to long-term use of the casing at high temperatures. 47
Using the outputs of the temperature calculator 43 and the stress adder 44, calculate the number of repeated failures N _f from the above equation (12), and execute the calculation of equation (16) to calculate the number of failures per unsteady operation. Calculate the accumulated fatigue damage amount △φ _f . The damage amount adder 48 is connected to the damage amount calculator 4 for each unsteady operation.
This is to add the outputs of 7. FIG. 8 shows the functional procedure of the damage amount calculator 47 and damage amount adder 48 of FIG. 4 described above for the fatigue damage amount accumulation calculation section.

Next, the accumulation of creep damage, which is another type of damage accumulation due to crack initiation, is due to continued steady operation at high temperature and constant stress.
The amount of creep damage △φ _c accumulated per unit time during continuous steady operation is calculated using equation (17).

Δφ _c =1/T _r (17) Here, T _r is the temperature during steady operation and the creep failure time due to the action of stress at that time.
Therefore, the amount of creep damage Δφ _c accumulated per unit time of steady operation can be determined by determining the creep rupture time T _r and executing the calculation of equation (17). In FIG. 4, the material property calculator 46 calculates the creep ramp characteristics from the hardness of the casing flange portion 32, taking into account the change in properties due to long-term use of the casing at high temperatures, so the damage amount calculator 47 uses the output of the stress adder 44 during steady operation to calculate the Larson Miller parameter P from equation (15), and then uses the output of the temperature thermal stress calculator 43 during steady operation to calculate ( 13) From the relationship between the Larson-Miller parameter P, temperature T, and creep failure time T _r in equation Perform the calculation to calculate the creep failure time T _r ,
The amount of creep damage △φ _c accumulated per unit time during steady operation is calculated by executing the calculation of equation (17).
The damage amount adder 48 sequentially adds the output of the damage amount calculator 47 during steady operation. FIG. 9 shows the functional procedure of the damage amount calculator 47 and the damage amount adder 48 for the creep damage amount accumulation calculation section.

Therefore, the damage accumulation amount calculated based on the material properties as described above is sequentially transferred to the diagnostic device 49, and the diagnostic device 49 combines the output result of the tolerance value calculator 50 and the output result of the damage amount adder 48. Diagnose by comparing.

Next, calculation and diagnosis of allowable values will be explained.

Tolerable values for structural members such as casings used at high temperatures are determined based on various material properties that are the high temperature strength characteristics of the member. Their material properties are tensile strength, yield strength, and creep rapture properties. Tolerances are usually set by setting a safety factor to the median or lower limit of the data band in the unused state of material properties, but as mentioned above, these material properties change due to long-term use at high temperatures, so it is not acceptable. Both the value and its changes need to be considered. The internal tensile strength, yield strength, and creep rapture properties of the material properties can be calculated by measuring the hardness of the member as described above.

In FIG. 4, the allowable value calculator 50 combines the output from the temperature calculator 43 with the tensile strength, yield strength, and creep rapture properties calculated by the material property calculator 56 based on the measured hardness values. Determine the allowable value for the applied stress by providing the necessary safety factor. Furthermore, tolerance values with necessary safety factors are built in for each of fatigue damage amount, creep damage amount, and their combination.

Next, the diagnostic device 49 will be explained. The diagnostic device 49 includes a stress adder 44 and a damage amount adder 48.
While comparing the output of and the output of the allowable value calculator 50, the state of the applied stress and damage accumulation amount of the member used for a long time at high temperature is determined, and the output is given to the display/warning device 51 as necessary. . Display alarm device 5
1. In accordance with the output result based on the diagnosis result of the diagnosis device 40, the state of the applied stress and damage accumulation amount of the high-temperature member is displayed. Furthermore, based on the future operation plan, the output results of the damage calculator 47 and the damage amount adder 48 are calculated based on the expected future operation history inputted from the condition setter 52. Diagnostic results are displayed by the diagnostic device 48, and an alarm is also generated if necessary.

Finally, the function of the condition setter 51 will be explained.

When the above-described device according to the present invention is installed in an existing thermal equipment, the amount of damage accumulated due to operation before installation remains unknown, and even if the amount of damage accumulated after that is calculated, highly accurate damage diagnosis is not possible. Can not. Therefore, in order to solve this problem, we installed the device of the present invention, including the temperature and stress conditions in typical operation patterns in the operating history before installing the device of the present invention, the number of unsteady operations, and the steady operation time. It is also possible to set all the parameters necessary to calculate the accumulated amount of damage based on the previous driving history. Therefore, even if the device of the present invention is installed in an existing thermal device, it is possible to grasp the amount of damage accumulated from the start of operation of the device and to perform predictive diagnosis of the period during which the device can be used without any problems.

Another way to use the condition setter 51 is to set in advance all the parameters necessary to calculate the accumulation and progression of damage based on the expected operation history, and set the actual equipment usage state quantities and material state quantities. Accumulation and progression of damage can be calculated without actually measuring damage.

In addition, although the above-mentioned example explained the case where it was applied to the rotor of a steam turbine, the present invention is not limited to this and can be applied to a portion of equipment used at high temperatures.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, temperature and stress are calculated from the usage state quantities of structural members used at high temperatures, material properties are calculated from the hardness of the structural members, and conditions are further set. The system calculates the amount of damage accumulated in structural members by making adjustments according to the operating history, and compares it with the allowable value, making it possible to accurately predict when cracks will occur in structural members. be able to.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the device of the present invention, Fig. 2 is a half sectional view showing a high temperature section of a steam turbine which is an example of equipment applicable to damage diagnosis of the present invention, and Fig. 3 is a block diagram showing the device of the present invention. FIG. 4 is a cross-sectional view showing how a hardness tester is installed in the casing of a steam turbine high temperature section, FIG. , in the block diagram of Fig. 4, a flowchart showing the functional procedure of the material property calculator, Fig. 6 a flowchart also showing the low cycle fatigue characteristics, and Fig. 7 a flowchart also showing the creep burst characteristics. Figure 8 is a flowchart showing the functional procedure of the damage amount calculation unit and damage amount adder in the block diagram of Figure 4, and Figure 9 is a flowchart showing the creep damage amount accumulation calculation unit. be. 1...Detection device, 2...Temperature-stress calculator, 3
...Measuring device, 4...Material property calculator, 5...Damage calculator, 6...Tolerance value calculator, 7...Diagnostic device, 8...Display alarm device.

Claims (1)

[Claims] 1. Detecting a usage state quantity, which is a physical quantity representing the usage environment of a high-temperature structural member, and calculating the temperature and stress acting on the structural member based on this, while measuring the hardness of the structural member. Based on this, the tensile strength, yield strength, low cycle fatigue properties, and creep collapse properties are calculated, and based on these calculated values, the structural members are tested for repeated unsteady operation of the equipment in which the structural members are used. Calculate the amount of damage to a structural member until a crack occurs, which is the amount of accumulated fatigue damage and the amount of creep damage accumulated due to continued steady operation, and compare it with the allowable value to calculate the amount of damage until a crack occurs. 1. A method for diagnosing damage to structural members used at high temperatures, the method being characterized by being able to predict and diagnose the period of . 2. The damage diagnosis method according to claim 1, wherein the tensile strength and yield strength are calculated using a linear formula of Vickers hardness that includes two coefficients that are a function of temperature. 3 The low cycle fatigue characteristics are determined by the relationship between the elastic strain range and the number of failure cycles, including coefficients and indexes that are a function of the Vickers hardness, and the plastic strain range and the number of failure cycles, including coefficients and indexes that are not dependent on the Vickers hardness. 2. The damage diagnosis method according to claim 1, wherein the damage diagnosis method is calculated from a relational expression. 4. The creep burst characteristic is calculated by expressing the Larson-Miller parameter, which indicates the relationship between temperature and rupture time, by a linear equation of Vickers hardness that includes two coefficients that are a function of stress. A method for diagnosing damage according to claim 1. 5. A patent characterized in that the allowable value is the tensile strength calculated from the hardness of the material, the allowable stress value calculated from the creep rapture property, and the crack initiation limit damage value of a combination of fatigue and creep. A damage diagnosis method according to claim 1. 6. A detection device that detects the state of use of a structural member used at high temperatures, a hardness measurement device that measures the hardness of the material of the structural member, and a hardness measurement device that detects the state of use of a structural member used at high temperatures. a temperature stress calculator that calculates the temperature and stress of the material; a material property calculator that calculates mechanical material properties from the hardness of the material measured by the hardness measuring device; The amount of accumulated damage is determined based on the output from the temperature stress calculator and material property calculator and the set values set by the condition setter. a damage calculator that calculates the temperature stress calculator and the material property calculator, a tolerance calculator that calculates the allowable value of the structural member from the outputs of the temperature stress calculator and the material property calculator, and a comparison of the outputs of the damage calculator and the allowable value calculator. Damage diagnosis for structural members, comprising: a diagnostic device that predicts and diagnoses the period until a crack occurs in a structural member; and a display/warning device that displays diagnostic data and issues an alarm when an abnormality is predicted to occur. Device.