JP2007192781A - Evaluation method and device for evaluating material deterioration behavior by tracer hydrogen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an evaluation method and device for measuring/evaluating precisely and easily a deteriorated/damaged state inside a material, by releasing hydrogen in a practical material by temperature elevation release analysis to analyze the released hydrogen obtained therein. <P>SOLUTION: The hydrogen captured or solid-dissolved in the material is released to an outside of the material by temperature elevation, and a material deterioration behavior is evaluated based on information obtained by the temperature elevation released hydrogen. The evaluation method/device include with a heating means for eliminating/releasing the hydrogen captured or solid-dissolved in the material, a collection means for collecting the eliminated/released hydrogen, a hydrogen information acquisition means for acquiring information as to the temperature elevation released hydrogen, and an information analytical means. The deteriorated/damaged behavior inside the material is investigated based on an elimination characteristic of the hydrogen captured in a deteriorated texture. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for degrading hydrogen trapped or dissolved in a metal material by temperature programmed desorption, and evaluating degradation / damage properties in the material based on the information of the temperature desorbed hydrogen, and the evaluation of the actual plant The present invention relates to a material degradation property evaluation apparatus including a measurement mechanism for an actual machine necessary for non-destructive implementation of the material.

  More than 70% of the thermal power plants in Japan are aged plants that operate 100,000 hours or more, and because of environmental problems, the life of the aged facilities is extended, maintenance costs are reduced, and steam is heated to high temperature and pressure to improve power generation efficiency. Etc., and is in a more severe driving situation. For this reason, it is necessary to ensure transparency and certainty for maintenance inspections of plant equipment, and in particular, quantitative and simple evaluation of material deterioration and damage over time using non-destructive methods, and remaining life There is a demand for a technique for predicting the above with high accuracy.

In general plant equipment maintenance inspection, nondestructive inspection methods such as ultrasonic inspection, radiation inspection, magnetic particle inspection, penetration inspection, and overcurrent inspection are frequently used. The detection target of such a method is mainly “damage”, that is, an effective method when a macro change such as thinning or cracking occurs in the material. However, this "damage" is caused by changes in the mechanical properties of the material due to micro- or nanometer-level micro changes in the metal structure, that is, as a result of the accumulated "deterioration" of the material, or from these "deterioration" parts. Therefore, at the stage where “damage” actually occurs, the deterioration of the material is in a considerably advanced state, and most of the material has already reached the middle to the end of its life. On the other hand, in the maintenance inspection of actual plant equipment, it is important how to detect the secular change of materials at an early stage. Since the damage treatment (repair) may be minor, it is advantageous in terms of economy. Therefore, the development of a method for quantitatively evaluating the material “deterioration” as early as possible is required, and various research and development have been conducted so far.

  For example, in the “method for evaluating the degree of sensitization of stainless steel” described in Patent Document 1, a gas such as hydrogen is added to a replica film to which the metal structure of the austenitic stainless steel surface is transferred, and the transfer on the film is performed. A method for measuring the degree of sensitization of the material surface by measuring hydrogen trapped in the tissue by a temperature programmed desorption analysis method is disclosed.

  Further, in the “Method and apparatus for predicting the life of plant structure” described in Patent Document 2, the same metal test piece as the material to be evaluated is exposed to the actual corrosive environment where the plant equipment is exposed, and the test is performed. There is disclosed a method for predicting the lifetime due to environmental cracking damage by comparing information on the amount of hydrogen permeating through the piece and the permeation speed information with a known master curve.

  The “defect detection device and its measurement method” described in Patent Document 3 uses an analysis device based on the principle of ionizing and desorbing atoms from the material surface, and introduces deuterium into various tissue factors in the material. A technique for detecting and visualizing defects in a material at an atomic level by detecting hydrogen ionized together with atoms constituting a tissue factor by trapping is disclosed.

The hydrogen thermal desorption analysis method is an analysis method that has been applied in the field of delayed fracture (hydrogen embrittlement), and there are many academic literatures. In a recent study shown in Non-Patent Document 1, there is a report example that the release profile of temperature-programmed desorption hydrogen is separated into profiles derived from each tissue factor.
Japanese Patent Laid-Open No. 7-113801 JP-A-8-68731 JP-A-9-152410 T.A. Yokota and Shiraga: “Evaluation of Hydrogen Content Trapped by Vanadium Precipitates in a Steel”, ISIJ International, Vol. 43, 2003, pp, 534-538.

  However, among the conventional material property evaluation methods, the method described in Patent Document 1 is a deterioration property evaluation method specialized for stress corrosion cracking susceptibility evaluation on the surface of austenitic stainless steel. A method for evaluating the properties is not disclosed. In addition, this method does not directly evaluate hydrogen and other gases that have been desorbed from the surface of the stainless steel, which is the object to be inspected, but indirectly using the gas released from the transfer tissue on the replica film. Since this is a typical evaluation method, there is a concern that the evaluation accuracy may be reduced compared to the direct evaluation method. Further, although it is conceivable that the amount of hydrogen trap increases or decreases depending on the etching level of the surface of the object to be inspected, which is a variable factor, that is, the quality of the replica, the solution has not been clarified. Furthermore, in this method, details of methods for performing “hydrogen trap processing” and “hydrogen thermal desorption analysis”, which are steps after the replica collection operation, are not clarified.

  The technique described in Patent Document 2 is specialized in life prediction regarding damage to a metal material mainly caused by stress corrosion cracking in a corrosive environment, and a method for evaluating the deterioration property of the material has not been clarified. In addition, this method measures hydrogen in the actual corrosive environment that has permeated through the sensor and predicts the life of stress corrosion cracking, and does not use thermal desorption hydrogen. Furthermore, in this method, it is necessary to install a metal material to be used as a sensor inside the actual machine. Therefore, it is conceivable that there are positional restrictions related to sensor installation when performing the evaluation.

  The technique described in Patent Document 3 is a method in which the deuterium is trapped at a defect, dislocation, grain boundary, or interface of a material, and the deuterium is detected together with atoms constituting the material to detect the defect, dislocation, or grain boundary. A defect detection method characterized by visualizing an interface. This method analyzes ionized hydrogen and does not use temperature-programmed desorption hydrogen. The purpose of the method is to detect the defect position, and although the visualization of the defect position is described, the method for evaluating the deterioration property of the material is not specified. Furthermore, since this method requires an analyzer for ionizing atoms, it is difficult to perform non-destructively on large members such as constituent parts of an actual plant.

  In Non-Patent Document 1, an attempt is made to separate the release profile of temperature-programmed desorbed hydrogen into a profile derived from tissue factor. The purpose is to correlate malignant hydrogen involved in delayed destruction of metal material and tissue factor. Hydrogen itself is not intended to be used as a tracer for evaluating material deterioration and damage characteristics. Therefore, this document does not specify a method for evaluating material deterioration / damage properties.

  The present invention has been made against the background described above. Hydrogen in a material is released by temperature-programmed desorption, and the degradation / damage state in the material is determined based on the temperature-programmed desorption hydrogen information obtained at that time. It is something to be evaluated.

  That is, in the invention of the material degradation property evaluation method using tracer hydrogen according to the present invention, the invention according to claim 1 is characterized in that hydrogen trapped or dissolved in a metal material as an object to be inspected is released to the outside of the material by raising the temperature. The deterioration / damage property in the material is evaluated based on the information obtained from the temperature-programmed desorption hydrogen.

  According to a second aspect of the invention of the material degradation property evaluation method using tracer hydrogen according to the second aspect, in the first aspect of the present invention, the temperature-programmed desorption derived from the tissue factor related to the material degradation / damage from the information on the temperature-programmed desorption hydrogen The evaluation is performed by separating information on hydrogen separation. In addition, the said tissue factor intends what is generally recognized as an observation object by an optical microscope and an electron microscope in a metal material structure | tissue.

According to a third aspect of the invention of the material degradation property evaluation method using the tracer hydrogen according to the first aspect, the hydrogen is released from the material in which hydrogen is trapped or dissolved by active addition of hydrogen. The evaluation is performed by temperature-programmed desorption hydrogen.

The invention of the material degradation property evaluation method using tracer hydrogen according to claim 4 is characterized in that, in the invention according to any one of claims 1 to 3, the evaluation is performed by changing the release profile of the temperature-programmed desorption hydrogen. And

  The invention of the material deterioration property evaluation method using tracer hydrogen according to claim 5 is the invention according to any one of claims 1 to 4, wherein the evaluation is performed by a change in peak height in the temperature release desorption hydrogen release profile. It is characterized by performing.

  The material deterioration property evaluation method using tracer hydrogen according to claim 6 is characterized in that, in the invention according to any one of claims 1 to 5, the evaluation is performed based on the amount of released hydrogen of the temperature-programmed desorption hydrogen.

The invention of the material degradation property evaluation method using tracer hydrogen according to claim 7 is the invention according to any one of claims 1 to 8, wherein the high Cr ferrite system in which hydrogen is captured or dissolved by active addition of hydrogen. The heat-resistant steel is characterized in that the evaluation is performed on the heat-resistant steel on the basis of information on the temperature-programmed desorbed hydrogen released when the temperature is raised at a heating rate of 100 ° C./hour.

  The invention of the material degradation property evaluation method using tracer hydrogen according to claim 8 is the invention according to any one of claims 1 to 7, wherein the material is a constituent part in an actual plant, and an arbitrary region of the constituent part is targeted. Thus, the evaluation is performed non-destructively.

  The invention of the material degradation property evaluation apparatus using tracer hydrogen according to claim 9 includes a heating means for desorbing / releasing hydrogen trapped or dissolved in the metal material to the outside of the material by heating, and desorbed / released It is characterized by comprising a collecting means for collecting the hydrogen, a hydrogen information obtaining means for obtaining information on the temperature-programmed desorption hydrogen, and an analysis information analyzing means.

According to the invention of the material degradation property evaluation apparatus using tracer hydrogen according to claim 10, in the invention according to claim 9, hydrogen can be actively added to trap or dissolve hydrogen into the material. It is characterized by that.

  The invention of the material degradation property evaluation apparatus using tracer hydrogen according to claim 11 is the invention according to any one of claims 9 and 10, wherein the heating means has a uniform area or volume at any part of the material. It is characterized in that the temperature of the heating can be increased under continuous or stepwise control.

  The invention of the material deterioration property evaluation apparatus using tracer hydrogen according to claim 12 is the invention according to any one of claims 9 to 11, wherein the heating means supplies energy used for heating and heating to a certain region of the material surface. It is characterized by being concentrated.

The invention of the material property evaluation apparatus using tracer hydrogen according to claim 13 is the invention according to any one of claims 9 to 12, wherein an inner layer cell that covers the material by exposing a measurement surface of the material, and the inner layer cell A carrier gas supply pipe having one end connected to a carrier gas supply source and a hydrogen capture supply pipe having one end connected to the hydrogen information acquisition means are airtightly connected to the inner layer cell. Further, the heating means for heating the measurement surface of the material is arranged outside the outer layer cell, and at least a part of the outer layer cell and the inner layer cell is heated by the heating means toward the measurement surface. It is possible to pass.

  The invention for a material property evaluation apparatus using tracer hydrogen according to claim 14 is characterized in that, in the invention according to claim 13, the inside of the outer layer can be evacuated.

The invention of the material property evaluation apparatus using tracer hydrogen according to claim 15 is the invention according to any one of claims 11 to 14, wherein the material is an arbitrary component in an actual plant. .

  So far, research on hydrogen and metal materials has been advanced from the viewpoint of elucidating the mechanism of delayed fracture, that is, harmful mechanical property changes caused by hydrogen in metal materials, and developing a suppression method. Is also applied as one of the evaluation methods. The temperature programmed desorption analysis method simulates the state of delayed fracture by adding hydrogen to the test piece, and then uses the temperature desorbed hydrogen released from the test piece to delay the metal material. It is for investigating the correlation between malignant hydrogen involved and tissue factor, and hydrogen is used as a material for simulating a delayed fracture state.

On the other hand, the present invention similarly uses the temperature programmed desorption analysis method, but actively utilizes the properties of hydrogen having the smallest atomic size, and this hydrogen, which is malignant against delayed fracture, is used only as a tissue. It is actively used as a property tracer to evaluate deterioration and damage in materials rather than thermal desorption hydrogen, and the method of using hydrogen is significantly different from the analysis method applied to delayed fracture. ing. From this fact, it can be said that the present invention is a novel invention based on an unconventional idea / concept.

It is known that deterioration of metallic materials is accompanied by various organizational changes. On the other hand, since the existence state of hydrogen in the material and the subsequent desorption characteristics change depending on the properties of various tissues, by measuring the temperature-programmed desorption hydrogen released from the metal material and capturing the change, Information on tissue factors involved in material degradation and damage resulting therefrom can be obtained. In addition, in the present invention, by directly devising a measurement device for actual equipment, direct and non-destructive hydrogen thermal desorption analysis for heavy and long members such as actual plant structural materials, which was impossible until now, However, it can be implemented, and can be used as a non-destructive material degradation property evaluation method for actual plant structural materials.

The present invention pays attention to the following problems and solves them, and thus has achieved an unprecedented original function, application, and effect.

(1) The hydrogen release characteristics obtained from thermal desorption analysis vary greatly depending on the material, specimen shape, hydrogen charge conditions, measurement conditions, etc. In conducting the evaluation, it is essential to elucidate various measurement suitable conditions and elucidate the relationship between the temperature-programmed desorption hydrogen and the corresponding tissue factor. This necessary solution is hereinafter referred to as “problems relating to a material deterioration evaluation method by temperature-programmed desorption hydrogen analysis”.

(2) The conventional hydrogen temperature programmed desorption analysis method is performed by a stationary measuring device installed in a laboratory, and a small test piece inserted in an airtight chamber provided in the device is fixed. Heating is performed at a rate of temperature increase, and information on the temperature-programmed desorbed hydrogen released from the sample at that time is obtained. Therefore, it is impossible to apply hydrogen thermal desorption analysis directly and non-destructively to large members such as actual plant structural materials with the above-mentioned conventional apparatus. It is difficult to obtain a necessary function for performing nondestructive evaluation in an actual machine required by the present invention only by applying the improvement. Therefore, in the present invention, a means for heating a certain region on an arbitrary member under uniform conditions while controlling the rate of temperature rise, a means for collecting released hydrogen, and information on the released hydrogen are obtained. In addition, it is necessary to develop a new device equipped with means for performing analysis. The above necessary solution problems are hereinafter referred to as “problems relating to an actual machine measuring apparatus”.

(1) Issues related to material degradation evaluation methods by temperature-programmed desorption hydrogen analysis [1] “Elucidation of suitable measurement conditions” and [2] “temperature-programmed desorption hydrogen and various material structures corresponding to them” Elucidation of the relationship.

  [1] “Elucidation of suitable conditions” is positioned as a necessary precondition for accurately performing material deterioration / damage evaluation based on information of temperature-programmed desorption hydrogen. Therefore, we examined the shape, weight, hydrogen storage capacity, diffusion rate, etc. of the object to be inspected, as well as the active hydrogen addition method and time, and hydrogen thermal desorption after hydrogen was actively added. By conducting theoretical / experimental analysis on the time required for heating, the rate of temperature rise, the temperature rise temperature range, etc., and reflecting the various preferred conditions obtained in the experiment / examination in the present invention, the material can be accurately obtained. It became possible to perform deterioration evaluation.

As an example of the preferred conditions, a preferred example obtained for the temperature rise is shown. In the temperature programmed desorption analysis of hydrogen, it is necessary to obtain a sufficient amount of hydrogen and an appropriate amount of change over time of hydrogen release for evaluating material properties. As a result of experiments and examinations, when the rate of temperature rise is too slow, the hydrogen release rate changes sensitively depending on the temperature, so it is possible to evaluate the change over time of the temperature-programmed desorption hydrogen in detail. It has been clarified that the amount of hydrogen released is reduced. On the other hand, if the rate of temperature rise is too fast, the amount of hydrogen released per unit time increases, which is an advantage in analyzing and comparing the amount of hydrogen. It became clear that it was not possible. In addition, in order to make the temperature-desorbed hydrogen measurement conditions constant, it is also effective to uniformly capture or dissolve hydrogen in the material that is the object to be inspected. It has been found that this can be achieved by actively adding hydrogen.

As a result of the above examination, in a specific measurement system system, the deterioration property of the material is improved by raising the temperature of the material to which hydrogen is actively added at a rate of temperature rise of 100 ° C./hour. It has been clarified that the information on the temperature-programmed desorption hydrogen necessary for the evaluation can be obtained in a form that contributes to the improvement of the evaluation accuracy.

The preferred conditions presented here are effective for a specific material and measurement system. However, by using the same concept and method, the preferred conditions can be provided for other materials and measurement systems. I can do it.

  [2] A method and concept for “elucidation of relationship between temperature-programmed desorption hydrogen and various material structures corresponding to it” will be described. In addition, the content shown below does not limit the range of this invention, but shows as an example. For example, to reproduce the deterioration state such as creep damage and aging, which are typical deterioration phenomena in a high temperature operation plant, for a specific material system, systematic aging deterioration simulation was applied by applying various temperature, time and load stress. Make the material. While investigating the structural properties of the simulated deterioration material using various conventionally used analysis / evaluation techniques, the correlation with the degree of deterioration (eg, aging conditions, creep life ratio, degree of load stress) Quantify. Furthermore, the temperature-programmed desorption hydrogen of these deterioration simulation materials is measured under suitable conditions using a gas chromatograph with a temperature-heating mechanism, and the release profile is made into a database. The device for hydrogen analysis is not limited to gas chromatograph, but the release profile (hydrogen release amount, release rate, profile peak temperature, peak half-value width with respect to temperature and time) such as a quadrupole gas analyzer. Any other means can be used as long as the information can be obtained. By passing through such a method, it is possible to obtain a relationship (master curve) between any degree of material degradation and temperature-programmed desorption hydrogen, so that temperature-programmed desorption hydrogen obtained from the evaluation material and its master curve From this comparison, material deterioration can be evaluated.

  Meanwhile, some peaks and inflection points that reflect hydrogen release from the material appear on the release profile of hydrogen desorption hydrogen measured from alloy steel having a complex structure. This is because the measured release profile itself does not correspond to the release from a single tissue factor (trap site) but is formed to include hydrogen released from multiple tissue factors. . By separating and examining these, changes in the properties of individual tissue factors involved in material degradation can be accurately evaluated. The tissue factor is intended to be a metal material structure that is generally recognized as an object to be observed by an optical microscope and an electron microscope. Examples thereof include dislocations, lattice defects, voids, and solid solutions. Examples include elements, precipitates, carbides, crystal grain sizes, grain boundary structures, depletion / segregation regions, and various interfaces such as old γ grain boundaries, packet boundaries, block boundaries, and precipitate / matrix boundaries.

In order to identify peaks corresponding to individual structure factors, temperature-programmed desorption hydrogen data for basic steel types with a simple chemical composition and structure are accumulated, and furthermore, a test material that expresses only specific structure factors. Or, conversely, the temperature-programmed desorption hydrogen data of the test material (knockout mouse in genetic research) lacking a specific tissue factor is made into a database. For example, the influence of carbides on temperature-programmed desorption hydrogen data is separated by measuring the profile of steel that does not contain carbides and comparing the temperature-programmed desorption hydrogen data with the steel containing carbides. As a result, it can be seen at what temperature the hydrogen release from various carbides has a peak. Furthermore, by measuring and comparing the temperature-programmed desorption hydrogen data of steels with varying amounts of carbide, the temperature-programmed desorption hydrogen involved in the carbide (including changes in the emission profile, its peak height and the amount of hydrogen released) The influence of the amount of carbide on Further, from the temperature-programmed desorption hydrogen data of the cold-worked specimen, the influence of dislocation structures or lattice defects (atomic vacancies) on the temperature-programmed desorption hydrogen can be evaluated. Furthermore, the influence of grain boundaries can be extracted from a comparison between a polycrystalline material (coarse grain material, fine grain material) and a single crystal material. Through such means, the temperature-programmed desorption hydrogen derived from each tissue factor is clarified, and the shape of the release profile, the appearance temperature of the release peak, the peak of the release profile derived from the change in the properties of the tissue factor It is possible to grasp fluctuations in the value and the amount of released hydrogen. Changes in the characteristics of individual tissue factors by creating a database of the above-mentioned changes in various profile information accompanying changes in the amount of tissue factor, and further using the release profile separation method described below as needed. Can be evaluated with high accuracy.

  In order to separate the release profile corresponding to each tissue factor from the measured release profile of temperature-programmed desorbed hydrogen, there is a method of proceeding the calculation assuming that each separation profile can be approximated by a Gaussian distribution function. The peak temperature of the separation release profile derived from each tissue factor is extracted and set from the release profile as measured, the characteristics of the material to be evaluated, and comparison with the constructed database. Furthermore, by adjusting the parameters on the Gaussian distribution function related to the height and width of the separation profile so that the superposition of the individual separation profiles is approximately equal to the emission profile shape as measured (before separation). , Separation of the release profile can be achieved.

  As another release profile separation method, the difference between the release profiles measured from the respective materials (for example, the healthy material and the deteriorated material) to be compared in evaluating the material deterioration property is taken. Individual profiles derived from specific tissue factors that were included in the profile as measured by can also be separated and revealed.

In addition, the separation / release profile of temperature-programmed desorption hydrogen derived from each tissue factor is verified by calculating the activation energy of hydrogen desorption from the tissue factor using the peak appearance temperature of the separation / release profile. be able to. That is, theoretical calculations are performed based on the binding energy of hydrogen and each tissue factor (for example, dislocations), its density (dislocation density), activation energy of intra-lattice diffusion, etc. The validity of the appearance temperature of the temperature-programmed desorbed hydrogen can be evaluated.

(2) Issues related to actual machine measuring device The solution target of this problem is the development of a new device capable of directly measuring the hydrogen release profile for non-destructive actual plant structural members. Considering the method of using the apparatus and the conditions, etc., the mechanism to be provided in this apparatus is [1] “temperature raising and heating mechanism for raising the temperature of a certain region of the test surface under controlled conditions” and [2 ] "Cell mechanism for collecting released hydrogen" and [3] "Mounting and holding mechanism for fixing to material". In order to provide these mechanisms, the technologies devised and developed by the present invention are as follows.

[1] An infrared condensing method has been devised as an example of providing a “temperature raising and heating mechanism for raising the temperature of a certain region of a test surface under controlled conditions”. As a result of investigating using a condensing heater that uses infrared rays as heating energy, even on the surface of a large member where heat escapes to the surroundings, the working distance and output are well balanced, By using a reflector for converging infrared rays to the target region as necessary, it is possible to create a minute region with a uniform temperature distribution. By attaching a commercially available temperature raising program device to this infrared condensing heater, the temperature can be raised while being controlled continuously or stepwise under uniform conditions. This temperature rise region has a three-dimensional spread in the evaluation target portion, but the spread can be predicted by general-purpose heat transfer calculation. When the temperature of the large member is increased, heat is relieved to the surroundings by applying the residual heat while taking into consideration that the large member is not affected by the hydrogen added to the material in advance. Since the situation can be avoided, the temperature rise temperature control can be carried out without difficulty.

[2] As an example of providing “a cell mechanism for collecting released hydrogen” and [3] “an attachment holding mechanism for attaching and fixing to a material”, an actual hydrogen collection cell was conceived. The cell is a container for closely adhering to the material surface and collecting hydrogen released during heating, but as shown in [1], the target is infrared rays used as heating and heating energy. Since it is necessary to permeate the inside of the cell in order to reach the surface of the material, most of the cell body preferably has transparency such as quartz glass (hereinafter, explanation will be made assuming that quartz glass is used). In addition, assuming that a small amount of hydrogen is released and considering the sensitivity of the analyzer used for hydrogen analysis, it is desirable to make the cell volume as small as possible. However, the cell body must be equipped with a mechanism for fixing the cell to the surface of the material, a temperature raising mechanism, and the like, and must have both space and strength. Therefore, it is one method to separate the cell into an inner layer cell that collects hydrogen with a double structure and an outer layer cell for attaching various cell structure members. A double-wall structure consisting of an outer layer mainly composed of stainless steel + quartz glass and an inner layer mainly composed of quartz glass, and if the space between the two layers is evacuated, the cell body is brought into close contact with the actual member surface. Can also be achieved. Hydrogen released from the material is stored in the inner layer covering the temperature rising and soaking region, and is supplied to the hydrogen measuring device together with the carrier gas. In order to prevent leakage of released hydrogen gas, the method for adhering the cell to the surface of the material uses a sealing material having a performance capable of withstanding a high temperature state formed by temperature rise, and the method for adhering in the vacuum atmosphere described above If the material to be heated is a magnetic material, it is possible to form strong adhesion by using a magnet base together.

  It should be noted that the “means for solving the problems” described above in various ways have been described using one application example in the concept of means, and do not limit the present invention. Various changes and modifications are easily assumed within the scope of the technical concept related to the claimed items, and it is understood that these are also included in the technical scope of the present invention. For example, in the description of [1] “Temperature raising and heating mechanism for raising the temperature of a test surface under a certain area under controlled conditions”, infrared rays are used as a heating energy source. It is possible to use induction heating, a heating furnace with other heating elements, or the like. Assuming that these heating sources can supply effective heating energy required for measurement, the concept of supplying energy is exactly the same, and it is common sense that it is included in the technical scope of the present invention. Can understand.

  High-temperature structural materials such as high Cr ferritic heat-resistant steels exhibit excellent high-temperature properties through precise and complex structure control. It is necessary to evaluate various structure factors such as dislocation structures, precipitates, solid solution element concentrations, and grain boundary structures. However, in order to evaluate these tissue factors according to the conventional technique, it is necessary to perform a method using various analyzers such as TEM, SEM, SIMS, AES, and XRD suitable for the evaluation of each tissue factor. A lot of effort and time has been spent.

On the other hand, the present invention examines the degradation characteristics of the material from the temperature desorption characteristics of hydrogen trapped by the tissue factor that has undergone a property change due to degradation, and therefore can obtain the following effects.
(1) Degradation properties of a wide variety of tissue factors can be evaluated by a single measurement method, and the labor and time required for evaluating material degradation / damage can be greatly reduced.
(2) Improve the accuracy of material deterioration evaluation because it is a technique for acquiring a hydrogen release profile that contains information on material deterioration / damage properties directly from the metal material that is the object to be inspected rather than via a replica. Can also be fulfilled.
(3) It is possible to evaluate nondestructive material deterioration properties even for large materials to be evaluated.
(4) It is possible to evaluate the non-destructive material deterioration property without affecting the actual plant equipment in service without damage (sampling).
(5) Since initial material deterioration can be evaluated with high sensitivity, early detection of deteriorated equipment becomes possible, and the risk of damage to plant equipment can be reduced.
(6) At present, it can greatly contribute to the improvement of “plant safety and soundness”, which is widely regarded as a social need, and is a high demand from plant users. It is possible to provide a solution for “maintenance and maintenance with a good balance between reliability and economy”.

  Although the effects of the present invention have been described using a high-temperature structural material as the background technology, the scope of the present invention is not limited to this, and is for nondestructive evaluation of the deterioration properties of the material. It is possible to apply to various uses. For example, nondestructive evaluation of soundness and deterioration of structural metal materials used for hydrogen production, transportation, storage, filling, etc. in energy systems using hydrogen, including hydrogen storage alloys and hydrogen fuel cells Providing a technique for this is also considered as one application.

Hereinafter, representative embodiments of the present invention will be described.
First, the form of material deterioration property evaluation by hydrogen thermal desorption analysis will be described.

  FIG. 1 shows an example of a thermal desorption hydrogen release profile obtained from steels having different structures under the preferred measurement conditions studied. The X axis is the temperature rise, and the Y axis is the hydrogen release rate. It can be seen that there is a change in the shape of the release profile of the temperature-programmed desorption hydrogen (including the peak appearance temperature and peak height of the release profile) in each steel type. Here, in consideration of the structure factor of each steel type, the peak height increases for the release profile of high Cr ferritic heat resistant steel (10% Cr steel in the figure) having a large Cr content compared to pure iron and carbon steel. It can also be seen that the width of the peak is also widened. By utilizing this change, it is possible to evaluate the variation in the amount of the solid solution element from the temperature release desorption hydrogen release profile. Similarly, it was confirmed that the metal structure (ferrite / bainite / martensite, etc.), the precipitation form of precipitates, the dislocation density, and the like are also reflected in the hydrogen release profile.

  FIG. 2 shows an example of a temperature release desorption hydrogen release profile in a deterioration simulation material of a high Cr ferritic heat resistant steel. The X axis is the temperature rise, and the Y axis is the hydrogen release rate. This figure shows that hydrogen is actively added to unused materials and aging degradation materials (materials that consume 20% of the creep life) based on suitable measurement conditions studied in advance, and then the measured temperature rise It is a release profile of desorbed hydrogen. The peak appearance temperature of the deterioration simulation material is shifted somewhat to the low temperature side compared to the unused material, and the peak height is reduced to about one third. As described above, since the peak appearance temperature and the peak height of the release profile change as the deterioration of the material progresses, it is possible to evaluate the degree of deterioration of the material by using these information. Similarly, it has been clarified that the deterioration degree of the material is evaluated from the change in the shape of the release profile of the temperature-programmed desorbed hydrogen even in the deterioration simulated material subjected to the heat aging.

FIG. 3 shows an example of material deterioration evaluation based on the amount of hydrogen released from temperature-programmed desorption hydrogen. After actively adding hydrogen to unused high Cr ferritic heat-resisting steel and simulated deterioration material (material consuming 0.5, 5, 20, 40, 60, 86, 100% of the creep life) FIG. 3 shows the amount of released hydrogen (C _H ) calculated from the measured hydrogen release profile and plotted against the lifetime consumption rate. The X axis indicates the lifetime consumption rate, and the Y axis indicates the amount of hydrogen. In the process of changing the lifetime consumption rate from 0% to about 20%, the amount of released hydrogen (C _H ) decreases rapidly, and the subsequent decrease becomes relatively moderate. A decrease in creep life than the decrease of such release hydrogen content C _H can be evaluated. Further, as a similar example, it has been clarified that the amount of released hydrogen (C _H ) changes with deterioration of the material even in the deterioration simulated material subjected to heat aging.

An example of the analysis result of the structure factor for the high Cr ferritic heat resistant steel is shown in FIG. The schematic diagram shows the relationship between the content of the solid solution element in the matrix and C _H , and the X axis is the solid solution strengthening element (Mo, W) dissolved in the matrix of the test material, The Y axis shows the amount of released hydrogen (C _H ). In high Cr ferritic heat-resisting steels, it has been clarified in academic papers that depletion of solid solution strengthening elements (Mo, W) is involved in deterioration. From the figure, there is a clear correlation between the content of the solid solution element and the amount of released hydrogen (C _H ), and the amount of released hydrogen (C _H ) is a powerful index for evaluating material deterioration damage. I understand that Such assessment can of change of tissue factor, i.e. the reduction of solid solution strengthening element due to material deterioration is because it is reflected in the amount of hydrogen C _H.

In this way, it is possible to evaluate the degree of material degradation by using the shape of the emission profile including information such as peak height and peak appearance temperature and parameters such as the amount of released hydrogen calculated using it as indicators. As is clear from FIG. 3, it has excellent detectability with respect to deterioration at an early stage (for example, creep life consumption rate of 20% or less), which was difficult to detect with the conventional nondestructive inspection technology. You can see that

  Next, the concept of material deterioration property evaluation by separating the hydrogen release profile will be shown. FIGS. 5A and 5B show examples of hydrogen release profiles of new and deteriorated alloy steel. From the comparison of (a) and (b), the temperature-released hydrogen release behavior measured with material deterioration varies, that is, the overall release profile differs in shape, peak height, and hydrogen release amount. It can be seen that As shown in the figure, the measured profile includes hydrogen release peaks (P1, P2, P3) from a plurality of various tissue factors. In order to evaluate, it is necessary to separate the entire profile for each tissue factor. The profile separation can be calculated, for example, assuming that the separation profile exhibits a Gaussian distribution.

In addition, taking a difference between release profiles to be arbitrarily evaluated is also an effective method for separating release profiles. For example, in FIGS. 6 (a) and 6 (b), it is possible to reveal a plurality of peaks by taking the difference between the release profiles obtained from the new material and the deteriorated material.

For the separated release profiles, as shown in FIGS. 7 (a), (b) and (C), the information obtained from each separated release profile (here, the amount of released hydrogen) should be compared with a known master curve. Thus, the tissue factor can be evaluated. In the figure, as an example, the relationship between the amount of released hydrogen obtained from the separated release profile and the derived tissue factors A, B, and C related to deterioration is shown. From the graph of FIG. 7, the amount of released hydrogen decreases as the material progresses, and the increase in the derived tissue factor A, the decrease in the derived tissue factor B, and the decrease in the derived tissue factor C are quantitatively evaluated in association with the degree of deterioration. It becomes possible to do.

  FIG. 8 illustrates the concept of the correspondence between the separated release profile and the tissue. As shown in FIGS. 5 and 7, changes in the separated release profiles P1, P2, and P3 are considered to be caused by changes in the derived tissue factors (A, B, and C) related to deterioration. As described above, since the separation and release profile also fluctuates greatly together with the derived tissue factor that has changed due to deterioration, it can be understood that each separation and release profile is a useful index for evaluation of deterioration properties. The relationship between each release profile shown here and its derived tissue factor is shown as an example to help understanding of the concept of this patent. The appearance of the release profile, its changing tendency, and the profile It is easily assumed that the form of separation and the name of the derived tissue corresponding to each peak differ depending on the type of material and its properties. However, by using the method for identifying and separating the release profile as described above, each separated release profile can be used as a useful index for tissue factor evaluation associated with material deterioration / damage.

  Next, FIG. 9 shows an example of a material property evaluation apparatus for actual machine measurement as a schematic diagram. In the following, a temperature-programmed desorption analysis method is applied to actual equipment (actual plant material) to obtain a material. An apparatus configuration example when performing property evaluation will be described. This material property evaluation apparatus 1 includes a hydrogen charging apparatus 10 for actively adding hydrogen to a material, and a hydrogen collection cell 20 with a temperature raising and heating mechanism that raises the temperature of the material after hydrogen addition and collects hydrogen. And have. The cell 20 is connected to a carrier gas supply source 20 via an air supply pipe 21 on the gas introduction side, and a hydrogen analyzer 40 as hydrogen information acquisition means is connected to the gas discharge side via an air supply pipe 22. ing.

  Details of a hydrogen charging apparatus for actively adding hydrogen will be described with reference to FIG. The example presented here is based on an electrochemical technique. In this embodiment, an arbitrary charge surface (sample electrode) 2a having a predetermined area is exposed and covered outside in the material 2 which is a constituent part of an actual machine. A masking material 11 made of a paint or film having chemical resistance and non-conductivity, a cylindrical cell container 12 disposed on the masking material 11, and a counter electrode 13 disposed in the cell container 12; Conductive wires 14 are electrically connected to the material 2 side. In the arrangement of the cell container 12, a filler 16 having adhesiveness or sealing property may be used in order to secure the material 2 and the adhesion to the masking material 11. An electrolytic solution 15 is accommodated in the cell container 12. As a result, the electrolytic solution 15 stored in the cell container 12 and the predetermined charge surface 2a are in direct contact with each other, so that the hydrogen electrolysis charging operation equivalent to the beaker test in the laboratory can be performed. The liquid temperature may be maintained by installing a heater or the like inside or outside the cell container 2.

  After the above installation and preparation, an appropriate current is passed between the charge surface (sample electrode) 2a and the counter electrode 13 to charge the hydrogen generated in the charge surface (sample electrode) 2a into the material 2. By combining this cell with a constant current / constant voltage device, it is possible to perform hydrogen electrolysis charging under suitable conditions for a predetermined portion. After charging, the charge surface (sample electrode) 2a is immediately washed and dried, and subjected to hydrogen temperature rising analysis. In order to make the spontaneous release amount of hydrogen before the start of temperature rise constant, it is desirable to manage the time until the start of temperature rise to be constant.

  The electrochemical method described above is only one of the methods for actively adding hydrogen, and various physical and chemical methods such as a method of directly exposing gas phase hydrogen to the evaluation target site should be adopted. The purpose can also be achieved.

  Next, an example of the hydrogen collection cell 30 with a temperature raising and heating mechanism that performs temperature rise heating and hydrogen collection for the evaluation target portion will be described with reference to FIG. The cell 30 corresponds to the heating means and the hydrogen collecting means of the present invention, and includes a cylindrical cap-shaped inner layer cell 32 that covers the charge surface 2a exposed as a measurement surface, and an inner cell 32 of the inner layer cell 32. A cylindrical outer layer cell 33 arranged concentrically at a distance from the outer peripheral side is provided. The inner layer cell 32 is made of transparent heat-resistant glass, and a transparent top plate 34 made of transparent heat-resistant glass is fixed to the outer layer cell 33. The inner layer cell 32 collects the released hydrogen and sends the hydrogen to the hydrogen analyzer 40. One side wall of the inner layer cell 32 is connected to an external carrier gas supply source 20 (not shown). A trachea 21 is connected, and an air supply pipe 22 connected to an external hydrogen analyzer 40 is connected to the other side wall. The outer layer cell 33 has a structure for fixing an infrared reflection furnace and a cell 30 described later as an example of a heating energy source to the surface of the actual machine. Further, an exhaust pipe 35 for evacuating the outer layer cell 33 is connected to the outer layer cell 33, and the exhaust pipe 35 is connected to a vacuum pump (not shown).

  Further, on the transparent top plate 34 of the outer layer cell 33, a condensing infrared reflection in which an infrared lamp 37, which is an example of a heating energy source, is disposed in an elliptical mirror 36 corresponding to an energy concentrating means toward the measurement surface. A furnace is installed, and the infrared reflection furnace is attached to the outer layer cell 33. Further, below the ellipsoidal mirror 36, an auxiliary condensing mirror 38 arranged in a cylindrical shape is installed.

  Next, the operation of the above apparatus will be described. The inner layer cell 32 is placed on the surface of the material 2 so as to cover the charge surface (sample electrode) 2 a of the material 2, and the outer layer cell 33 is arranged on the outer peripheral side thereof, and the inner layer cell 32 and outer layer cell are sealed by the sealing material 31. The space between the material 33 and the material 2 is hermetically sealed. Next, the outer layer cell 33 is evacuated through the exhaust pipe 35 by a vacuum pump (not shown). By vacuuming between the inner layer cell 32 and the outer layer cell 33, it is possible to prevent hydrogen existing in the external environment from being mixed into the inner layer cell 32 and to fix the cell 30 to the actual machine surface by a pressure difference. . Further, by using a magnet 39, a suction cup, an adhesive, etc., it is possible to attach firmly to the actual machine surface.

  Next, infrared rays irradiated from the infrared lamp 37 are irradiated to the evaluation target portion using the ellipsoidal mirror 36 and the auxiliary condensing mirror 38 to raise the temperature. The irradiation energy passes through the transparent top plate 34 and the inner layer cell 32 of the outer layer cell 33 and is irradiated to the charge surface (sample electrode) 2a. The actually measured temperature of the charge surface (sample electrode) 2a is measured by a thermocouple 39-1. At this time, by using a general-purpose temperature controller for controlling the output of the infrared lamp, a certain controlled temperature adjustment can be performed. In order to prevent the infrared rays from being irradiated to the peripheral portion other than the evaluation target, it is effective to use a heat shielding coating or a heat insulating material for a region other than the predetermined region as necessary. When the mass of the material to be evaluated is large and the dissipation of irradiation heat is remarkably hindered by the specified temperature rise control, an auxiliary heating device such as a rubber heater is applied to the material to be evaluated, and the hydrogen charged in the material is charged. This can be avoided by applying preheat in advance so as not to affect the process.

  During the heating, a carrier gas such as Ar is simultaneously supplied from the carrier gas supply source into the inner layer cell 32 through the air supply tube 21. Then, the temperature-released hydrogen is sent together with the carrier medium (carrier gas) to the hydrogen analyzer 40 through the air feed tube 22 and is subjected to analysis.

Next, the hydrogen analyzer will be described.
As shown in FIG. 12, the hydrogen analyzer 40 includes a gas chromatograph 41 for analyzing the gas sent from the air supply pipe 22, and measurement by a timer 42 is possible at regular intervals. The measurement result of the gas chromatograph 41 is configured to be output to the analysis unit 43 corresponding to the information analysis unit of the present invention. The analysis means 43 can be comprised by CPU and the program which operates this, for example. The analysis means 43 is connected to a storage device 44 made of an HDD, a flash memory or the like and capable of storing data, and a display means 45 such as a CRT for displaying the analysis result. The storage device 44 stores temperature-programmed desorption hydrogen release data of the standard sample, hydrogen amount peak value changes corresponding to changes in the derived tissue factor, deterioration degree evaluation data corresponding to hydrogen amount peak value changes, and the like. be able to.

  The hydrogen analyzer 40 can measure the amount of hydrogen released from the material 2 at a temperature set in the timer 42 (for example, every 5 minutes). At this time, the temperature with respect to the elapsed time can be known by managing the temperature increase rate in the heating means. The analysis means 43 can obtain a temperature-programmed desorption hydrogen release profile as shown in FIG. 6 from the measured hydrogen amount from the gas chromatograph 41, the measurement interval from the timer 42, the temperature rise data, and the like. In the analysis means 43, if necessary, a change in the peak amount of hydrogen corresponding to a change in one or more derived tissue factors is obtained by calculating the difference in the profile of the standard sample or separating the profile based on the Gaussian distribution. be able to. The analysis means 43 may store the hydrogen amount measurement data and the acquired profile in the storage device 44 or display them on the display means 45 without performing the difference or profile separation as described above. Good. In addition, in the analysis means 43, when acquiring the hydrogen amount peak value change corresponding to the change of the derived tissue factor, it is also possible to acquire the deterioration degree corresponding to the change amount from the data stored in the storage device. .

In other words, the properties of the actual material 2 can be grasped accurately and easily by these analyzes, and the deterioration can be evaluated with high accuracy. Although the present invention has been described based on the above embodiment, the present invention is not limited to the above description, and can naturally be modified without departing from the scope of the present invention.

It is a graph which shows the relationship between the discharge | release profile of temperature-programmed desorption hydrogen, and various materials corresponding to it in this invention. Similarly, it is a graph showing an example of a hydrogen release profile obtained from a temperature programmed desorption analysis for an unused material and a deterioration simulation material. Similarly, it is a graph which shows the example of material deterioration evaluation by the amount of hydrogen. Similarly, it is a graph which shows the relationship between the reduction | decrease of hydrogen amount, and the fall of content of a solid solution strengthening element. Similarly, it is a graph which shows an example of the discharge | release profile of temperature rising desorption hydrogen. Similarly, it is a figure which shows the relationship of the difference with the standard material in a hydrogen discharge | release profile. Similarly, it is a graph showing an example (concept) of the relationship between the release profile of separated thermal desorption hydrogen and the evaluation of tissue properties. Similarly, it is a figure which shows the example of correspondence (concept) with the discharge | release profile of the separated thermal desorption hydrogen, and a structure | tissue. It is a schematic diagram which shows the apparatus for real machine measurement in one Embodiment of this invention. Similarly, it is sectional drawing which shows a hydrogen charging device. Similarly, it is sectional drawing which shows a hydrogen collection cell with a heating-up heating mechanism. Similarly, it is a block diagram showing a hydrogen analyzer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Material property evaluation apparatus 2 Material 2a Charge surface (sample electrode)
DESCRIPTION OF SYMBOLS 10 Hydrogen charging apparatus 12 Cell container 13 Counter electrode 14 Conductor 15 Electrolytic solution 16 Filler 20 Carrier gas supply source 21 Air supply pipe 22 Air supply pipe 30 Hydrogen collection cell 32 with temperature rising heating mechanism Inner layer cell 33 Outer layer cell 34 Transparent top plate 35 Exhaust Tube 36 Ellipsoidal mirror 37 Infrared lamp 38 Auxiliary condensing mirror 39 Magnet 39-1 Thermocouple 40 Hydrogen analyzer 41 Gas chromatograph 42 Timer 43 Analyzing means 44 Storage device

Claims (15)

  The hydrogen trapped or dissolved in the metal material to be inspected is released to the outside of the material by raising the temperature, and the deterioration / damage properties in the material are evaluated based on the information obtained from the temperature-desorbed hydrogen. A material deterioration property evaluation method using tracer hydrogen.   The tracer hydrogen according to claim 1, wherein the evaluation is performed by separating information on the temperature-programmed desorption hydrogen derived from a tissue factor involved in material degradation / damage from the information on the temperature-programmed desorption hydrogen. Material degradation property evaluation method.   3. The material using tracer hydrogen according to claim 1, wherein the evaluation is performed by temperature-programmed desorption hydrogen released from the material in which hydrogen is captured or dissolved by active addition of hydrogen. Degradation property evaluation method.   The material degradation property evaluation method using tracer hydrogen according to any one of claims 1 to 3, wherein the evaluation is performed by changing a release profile of the temperature-programmed desorption hydrogen.   The material degradation property evaluation method using tracer hydrogen according to any one of claims 1 to 4, wherein the evaluation is performed based on a change in peak height in the release profile of the temperature-programmed desorption hydrogen.   The material degradation property evaluation method using tracer hydrogen according to any one of claims 1 to 5, wherein the evaluation is performed based on a released hydrogen amount of the temperature-programmed desorption hydrogen. For high Cr ferritic heat resistant steel in which hydrogen is trapped or dissolved by active addition of hydrogen, the temperature of desorbed hydrogen released when the temperature is raised at a rate of 100 ° C./hour The material degradation property evaluation method using tracer hydrogen according to any one of claims 1 to 6, wherein the evaluation of the heat-resistant steel is performed based on information.   The material deterioration due to tracer hydrogen according to any one of claims 1 to 7, wherein the material is a constituent part in an actual plant, and the evaluation is performed nondestructively for an arbitrary region of the constituent part. Property evaluation method.   Heating means for desorbing and releasing hydrogen trapped or dissolved in the metal material to the outside of the material by raising the temperature, collection means for collecting the desorbed and released hydrogen, and the temperature-desorbed hydrogen An apparatus for evaluating material deterioration properties by tracer hydrogen, comprising: hydrogen information acquisition means for acquiring information on information and information analysis means.   The material deterioration property evaluation apparatus using tracer hydrogen according to claim 9, wherein hydrogen can be actively added to the material to capture or dissolve hydrogen.   The heating means can heat and raise a temperature while controlling a constant region in an arbitrary part of the material under uniform conditions continuously or stepwise. Material degradation property evaluation equipment by tracer hydrogen.   The material deterioration property evaluation apparatus using tracer hydrogen according to any one of claims 9 to 11, wherein the heating means concentrates energy used for heating and heating in a certain region of the material surface.   The hydrogen collecting means has an inner layer cell for covering the exposed measurement surface of the material and collecting released hydrogen, and an outer layer cell for covering the inner layer cell. One end of the carrier gas supply source is provided in the inner layer cell. The heating means for heating the measurement surface of the material to the outside of the outer layer cell, wherein the connected carrier gas supply pipe and the collected hydrogen supply pipe having one end connected to the hydrogen information acquisition means are hermetically connected 13, and at least a part of the outer layer cell and the inner layer cell is configured such that heating temperature rise energy by the heating means can pass toward the measurement surface. The material deterioration property evaluation apparatus by tracer hydrogen described in 1.   The material deterioration property evaluation apparatus using tracer hydrogen according to claim 13, wherein the inside of the outer layer can be evacuated. The material deterioration property evaluation apparatus using tracer hydrogen according to any one of claims 9 to 14, wherein the material is an arbitrary component in an actual plant.

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