JP2001124763A - Method and system for diagnosing remaining life of gas turbine high-temperature part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a system for diagnosing a remaining life of a gas turbine high-temperature part whereby the remaining life can be highly accurately obtained with using precipitation of a degraded phase of a moving blade and a stationary blade of the gas turbine formed of an Ni group single crystal alloy containing Re as a parameter. SOLUTION: A relationship of a precipitation amount, a temperature and a time of a degraded phase is obtained for the gas turbine high-temperature part formed of the Ni group single crystal alloy containing Re. A use temperature is estimated from a particle size or a precipitation amount of a γ' phase of a surface of the high-temperature part of an actual apparatus. The remaining life is diagnosed by calculating a time when the degraded phase of a predetermined precipitation amount is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to Re (rhenium)
The present invention relates to a method and a system for diagnosing the remaining life of a gas turbine high-temperature component that is made of a Ni (nickel) -based single crystal alloy and that constitutes a moving blade and a stationary blade of a gas turbine.

[0002]

2. Description of the Related Art Heretofore, the design life of a gas turbine has not been taken into account by the influence of material deterioration during operation, but has been calculated based on a simplified model using a material database of materials used. For this reason, the material life is set to a safe side with respect to the actual life in consideration of a considerable safety factor at the time of design. In addition, the effects of the operating conditions of the gas turbine on the service life are roughly classified, and from this point too, the safety level is set to be overestimated.

As described above, the high-temperature components of a gas turbine are designed to have a design life that is considerably shorter than the actual life, and the frequency of replacement of the high-temperature components in use is high. It has been an efficiency issue.

[0004] Therefore, based on the creep or fatigue life determined at the design stage and the life (set life) set by the environmental conditions of the operation and location of the actual machine, the gas turbines of the same model and the same operation form are prioritized. Material deterioration diagnosis formula is created in a gas turbine that is operating in a typical manner, and the deterioration diagnosis formula is applied to the models that start operation thereafter,
Maintenance techniques have been developed and used to extend blade life by correcting the design life during use. As the life evaluation parameter, for example, a surface crack disclosed in JP-A-9-273978 or JP-A-8-160035, a γ ′ particle size disclosed in JP-A-4-25745, and the like are used. is there.

[0005]

As a high temperature component of a gas turbine, a single crystal alloy is used in place of a conventional ordinary cast alloy or a directionally solidified alloy due to an increase in combustion gas temperature for improving the efficiency of the gas turbine. It is becoming. CMS without adding Re even in single crystal alloy
X-2 (trade name of Canon Muskegon) or PWA-1
480 (product name of United Technology)
A second-generation single crystal alloy containing about 3 wt% of Re from a single crystal alloy of the generation, a CM containing 5 wt% or more of Re
Third such as SX-10 (trade name of Canon Muskegon)
Generational single crystal alloys are being adopted.

In such a single crystal alloy to which Re is added, a deteriorated phase called a sigma phase or an R phase is precipitated during use, and a surface crack which has been a problem in conventional ordinary cast alloys and directionally solidified alloys. Crack generation starting from the deteriorated phase and crack propagation progressing through the deteriorated phase are the life governing factors instead of parameters such as coarsening and γ 'phase coarsening. It is becoming difficult to do.

Accordingly, the present invention provides a gas turbine high-temperature component capable of accurately determining the remaining life of a rotor blade and a stationary blade of a gas turbine made of a Ni-based single crystal alloy containing Re, using precipitation of a deteriorated phase as a parameter. An object of the present invention is to provide a life diagnosis method and a remaining life diagnosis system.

[0008]

According to the first aspect of the present invention, there is provided a semiconductor device comprising:
The relationship between the precipitation amount of the deteriorated phase, the temperature and the time for gas turbine high-temperature components made of a Ni-based single crystal alloy containing Is calculated by calculating a time at which a predetermined amount of precipitation occurs.

The second aspect of the present invention is the most degraded by measuring the surface temperature distribution of the gas turbine high-temperature component in advance and measuring the particle size of the γ ′ phase in a portion where no coating is applied in the first aspect of the present invention. It is characterized in that the remaining life of a portion where the degree of phase precipitation is large is calculated in a non-destructive manner.

According to a third aspect of the present invention, the relationship between the amount of the deteriorated phase, the temperature, and the time is determined in advance for the high-temperature components of a gas turbine made of a Ni-based single crystal alloy containing Re, and the relationship has already been found on the surface of the actual high-temperature components. It is characterized in that it is performed by calculating the time during which the deteriorated phase has a predetermined amount of precipitation.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the most deteriorated state is obtained by measuring the surface temperature distribution of the surface of the gas turbine high-temperature component in advance and measuring the deposition amount of the degraded phase at the portion where the coating is not applied. It is characterized in that the remaining life of a portion where the amount of phase precipitation is large is calculated nondestructively.

A fifth aspect of the present invention is characterized in that, in the first or third aspect of the present invention, the remaining life diagnostic formula is calculated using an Nv value which is an index indicating the phase stability of the alloy. A sixth aspect of the present invention is characterized in that, in the first or third aspect of the present invention, the remaining life diagnostic expression is calculated using an Mdγ value which is an index indicating the phase stability of the alloy.

According to a seventh aspect of the present invention, there is provided a relational expression calculating means for calculating a relational expression between the precipitation phase of the alloy constituting the high temperature component of the gas turbine, the temperature, and the time, and the temperature distribution and the surface temperature of the actual machine part in the relational expression. And a remaining life calculating means for calculating the remaining life by substituting.

As described above, according to the present invention, N
The relationship between the precipitation amount of the degraded phase, the temperature and the time for the i-based single crystal alloy is obtained in advance, and the surface temperature is estimated from the particle size of the γ 'phase on the surface of the high-temperature component to calculate the deposition time of the degraded phase. Predict the life expectancy. For Ni-based single crystal alloys in which a small amount of the deteriorated phase is precipitated, the relationship between the amount of the deteriorated phase, temperature, and time is determined in advance, and the time required for the deteriorated phase, which has already been deposited on the surface of the high-temperature component, to reach the specified amount. Is calculated and the remaining life is predicted. In addition, analytically determine the surface temperature of high-temperature components such as gas turbine rotor blades in advance, and after polishing the metal structure to a mirror surface where the coating etc. does not cover the metal surface, transfer the metal structure with a replica film, By measuring the particle size of the γ 'phase and the amount of precipitated deteriorated phase, the amount of precipitated deteriorated phase at the portion where the deteriorated phase is considered to be most deposited is estimated, and the remaining life is estimated.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below. In the present embodiment, a case will be described in which the remaining life of a third-generation Ni-based single crystal alloy containing 5 wt% of Re as an additional element, in which the precipitation of a deteriorated phase is a life controlling factor, is estimated.

FIG. 1 is a flowchart showing a method of diagnosing remaining life of the present embodiment. That is, a high-temperature aging test of a material equivalent to an actual machine is performed in advance in a laboratory (step S1).
1) Measure the γ 'particle size of the aged test specimen and the amount of precipitated deteriorated phase. In addition, mechanical properties such as a creep test and a low cycle fatigue test are evaluated using the aging test material (step S12).
Subsequently, an equation for predicting the precipitation of the deteriorated phase is created from the aging time, the aging temperature, the precipitation start time of the deteriorated phase, and the coarsening rate of the deteriorated phase and the γ 'phase (step S13). Furthermore, a standardized life prediction formula was created taking into account the material criteria obtained from the evaluation of the mechanical properties, the variation in the material, and the safety factor in the design, and the horizontal axis indicates the material surface temperature and the vertical axis indicates the standardized life. A damage master curve is created (step S14).

Separately, a metal structure of a high-temperature component of an actual gas turbine is collected using a replica film (step S1).
5) Measure the γ 'particle size of the high-temperature component of the actual machine, and if the deteriorated phase is precipitated, measure the amount of the precipitated deteriorated phase (step S).
16). Next, the surface temperature of the high-temperature component of the actual machine is estimated from the γ ′ grain size and the precipitation amount of the deteriorated phase (step S17), and the remaining life is estimated by comparing with the damage master curve obtained in step S14 (step S14). Step S18).

FIG. 2 shows a procedure for creating a damaged master curve. This preparation procedure is roughly divided into a procedure for preparing a deteriorated phase precipitation prediction equation and a procedure for preparing a deteriorated phase precipitation rate dependent equation of mechanical properties.

Assuming that the creep characteristics and low cycle fatigue characteristics of the alloy of the high temperature component are the life controlling factors, a creep test and a low cycle fatigue test are performed as a mechanical characteristic evaluation test for preparing a master curve. First, test conditions are determined in consideration of the surface temperature of step (step S).
twenty one). Subsequently, based on the determined test conditions, a high-temperature aging test is performed using temperature and time as parameters (step S22). From this, using the temperature (T ') as a parameter, a prediction formula F = f (T') for the precipitation start time of the deteriorated phase is calculated (step S23).

Here, it has been found that this deteriorated phase has a relationship as shown in FIGS. 3 and 4 with respect to temperature and time with respect to Nv or Mdγ conventionally used for evaluating phase stability. Here, Nv and Mdγ in FIG.
The values do not include the effects of the elements. Mdγ is γ
It is an Md value calculated using the element concentration in the phase. FIG.
FIG. 4 shows that the Nv value or the Mdγ value is on the X axis and the time is Y
The axis of abscissa indicates the Re content on the Z axis, and the precipitation region of the deteriorated phase is hatched. From these figures, the Nv value is
When the Re content is in the range of 1.0 to 2.5 and the Re content is 2.5 wt% or less, and when the Mdγ value is 0.86 or more and 0.94 or less, the Re content is
It can be said that the deterioration phase can be predicted in the region of 2.5 wt% or less.

Subsequently, a prediction formula G = g (T ″) for calculating the time required to reach the amount of deposition of the deteriorated phase that determines the life of the mechanical characteristics described later is calculated (step S23). Then, in the next step S24, the deterioration phase precipitation start time F and the time G at which the predetermined precipitation rate is reached are added, and the deterioration phase precipitation prediction formula LP is added.
= F (T ′) + g (T ″).

Separately, the conditions of the low cycle fatigue test and the creep test are selected with reference to the stress and temperature of the high temperature parts of the actual machine obtained analytically at the time of design (step S25). Further, a test piece in which the precipitation amount of the deteriorated phase was changed was prepared in advance by a high-temperature aging test, and a creep test and a low cycle fatigue test were performed under the conditions determined in (Step S21) (Step S26). A prediction formula H = h (P, C, T) for estimating the time required to reach the deposition limit of the deteriorated phase is determined from the amount of precipitation and the results of the creep test and the low cycle fatigue test (step S27). Here, P indicates the applied stress in the creep test, C indicates the entire strain range in the low cycle fatigue test, and T indicates the temperature.

Next, in step S28, a consumption life formula (LP × safety factor) is created in consideration of the variation in material and the safety factor in the predicted deterioration phase precipitation time, and standardized together with the critical life H obtained from the mechanical characteristics. A life formula L is created.

FIG. 5 shows a comparison between the results of creep tests performed on the test pieces cut out from the test blades by determining the remaining life of the rotor blades subjected to the actual machine operation test by the above-described method. From this, it can be said that the remaining life obtained by the remaining life prediction method of the present invention has a high correlation with the remaining life obtained by the creep test.

FIG. 6 shows a comparison between the results of the low-cycle test performed on the test pieces cut out from the test blades by obtaining the remaining life of the stationary blades subjected to the actual operation test. From this, it can be said that the remaining life obtained by the remaining life prediction method of the present invention has a high correlation with the remaining life obtained by the low cycle test.

FIG. 7 shows the temperature distribution on the blade surface by analysis at the time of design and the precipitation distribution of the deteriorated phase by an operation test. There is a high correlation between the temperature distribution on the rotor blade surface and the amount of precipitated degraded phase, and by transferring the metal structure of the uncoated part to a replica film and measuring the γ 'grain size and the amount of precipitated degraded phase. It can be said that the remaining life can be estimated.

FIG. 8 shows the temperature distribution on the surface of the stationary blade by the analysis at the time of design and the precipitation distribution of the deteriorated phase by the operation test. There is a high correlation between the temperature distribution on the stator blade surface and the amount of the degraded phase deposited, and by transferring the metal structure of the uncoated portion to a replica film and measuring the γ 'grain size and the amount of the degraded phase deposited It can be said that the remaining life can be estimated.

[0028]

According to the method and system for diagnosing the remaining life of a gas turbine high-temperature component according to the present invention, the generation of a crack due to the precipitation of a deteriorated phase and the propagation of the crack are factors that govern the life of the second generation and high temperature parts. The remaining life of a turbine high-temperature component made of a third-generation Ni-based single crystal alloy can be nondestructively and quantitatively estimated.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a method of diagnosing remaining life of a turbine high-temperature component according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a procedure for obtaining a damage master curve in the embodiment.

FIG. 3 is a graph showing the relationship between the Re content, the phase stability evaluation index Nv value, and the deposition time and temperature of the deteriorated phase.

FIG. 4 is a graph showing the relationship among the Re content, the phase stability evaluation index Mdγ value, and the deposition time and temperature of the deteriorated phase.

FIG. 5 is a graph showing the relationship between the creep life of a deteriorated test piece cut out from a rotor blade and the remaining life estimated by the method of the present invention.

FIG. 6 is a graph showing a relationship between a low cycle fatigue life of a deteriorated test piece cut out from a stationary blade and a remaining life estimated by the method of the present invention.

FIG. 7 is a diagram showing a surface temperature distribution and a deposition distribution of a deteriorated phase of a test rotor blade.

FIG. 8 is a view showing a surface temperature distribution of a test vane and a precipitation distribution of a deteriorated phase.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroaki Yoshioka 2-4, Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture F-term in Toshiba Keihin Works (reference) 2G024 AD07 AD24 BA12 CA11 DA03 FA02 2G055 AA05 BA05 BA11 BA14 CA01 CA11 EA08 FA01 FA02

Claims (7)

[Claims] 1. The relationship between the amount of degraded phase deposited, the temperature, and the time for a gas turbine high-temperature component made of a Ni-based single crystal alloy containing Re is determined in advance, and the working temperature is determined from the particle size of the γ 'phase on the surface of the actual high-temperature component. A method of diagnosing the remaining life of a high temperature component of a gas turbine, wherein the method is performed by estimating a time when a deteriorated phase reaches a predetermined deposition amount. 2. Preliminarily measuring the surface temperature distribution of a gas turbine high-temperature component and measuring the particle size of the γ 'phase in a place where no coating is applied to reduce the remaining life of the place where the degree of precipitation of the deteriorated phase is large. 2. The method for diagnosing remaining life of a high temperature component of a gas turbine according to claim 1, wherein the calculation is performed nondestructively. 3. The relationship between the amount of the deteriorated phase, the temperature, and the time for a high-temperature component of a gas turbine made of a Ni-based single crystal alloy containing Re is determined in advance, and the deteriorated phase that has already precipitated on the surface of the actual high-temperature component is determined to be a predetermined value. A method for diagnosing remaining life of a gas turbine high-temperature component, wherein the method is performed by calculating a time at which the amount of precipitation is obtained. 4. Preliminarily measuring the surface temperature distribution of the surface of the gas turbine high-temperature component, and measuring the amount of the degraded phase deposited at a place where the coating is not applied, thereby increasing the remaining life of the location where the degraded phase is deposited most. 4. The method for diagnosing remaining life of a high-temperature component of a gas turbine according to claim 3, wherein the calculation is performed non-destructively. 5. A method for diagnosing a remaining life of a high temperature component of a gas turbine according to claim 1, wherein a remaining life diagnosing equation is calculated using an Nv value which is an index indicating phase stability of the alloy. 6. Mdγ which is an index indicating the phase stability of an alloy
4. The method for diagnosing a remaining life of a high temperature component of a gas turbine according to claim 1, wherein the remaining life diagnosing equation is calculated using the value. 7. A relational expression calculating means for calculating a relational expression between the precipitation phase of the alloy forming the high temperature parts of the gas turbine and the temperature and time, and substituting the temperature distribution and the surface temperature of the actual machine parts into the relational expression. And a remaining life calculating means for calculating a remaining life of the gas turbine high-temperature component.