Pressure-bearing equipment embrittlement evaluation method and related device

Abstract

The invention discloses a pressure-bearing equipment embrittlement evaluation method and a related device, and relates to the technical field of material embrittlement evaluation, and the method comprises the following steps: fitting ductile-brittle transition temperatures under a Charpy impact test in different embrittlement states and ductile-brittle transition temperatures under a small punch test in different embrittlement states; obtaining a fitting relational expression between the ductile-brittle transition temperature under the Charpy impact test and the ductile-brittle transition temperature under the small punch test, and during actual evaluation, taking the ductile-brittle transition temperature under the small punch test at the evaluation moment as input, and determining the material embrittlement degree of the to-be-evaluated pressure-bearing equipment by utilizing the fitting relational expression. According to the method, the fitting relational expression is constructed in advance, and during actual evaluation, since the size of the sample used by the small punch test is smaller than that of the sample used by the Charpy impact test, sampling can be directly carried out from the body of the pressure-bearing equipment, and the material embrittlement degree of the pressure-bearing equipment can be accurately determined without a hanging block, so that the material embrittlement degree of the pressure-bearing equipment can be accurately determined. And the embrittlement evaluation of the pressure-bearing equipment is completed.

Description

Technical Field

[0001] The present application relates to the technical field of material embrittlement assessment, and in particular to a method for assessing the embrittlement of pressure-bearing equipment based on micro-damage testing and related devices. Background Art

[0002] At present, more and more pressure-bearing equipment has entered or is about to enter the end of its design life. How to inspect and continue to use the pressure-bearing equipment that has exceeded its service life has become the focus of common concern of regulatory authorities, inspection and testing institutions and enterprises. Material embrittlement caused by temper embrittlement and hydrogen embrittlement is one of the main damages of pressure-bearing equipment after long-term service. From the production point of view, controlling the temper embrittlement sensitivity coefficients such as X coefficient and J coefficient and step cooling test can only ensure its initial toughness and anti-temper embrittlement performance. In order to obtain the actual embrittlement performance of the material, it is still necessary to supervise and evaluate the embrittlement performance of the material through regular inspection.

[0003] The most commonly used method in engineering is to regularly measure the ductile-brittle transition temperature of hanging block specimens to evaluate the degree of material embrittlement. However, as the service time of pressure-bearing equipment increases, there will be a dilemma of no hanging block specimens available. Summary of the invention

[0004] The purpose of this application is to provide a pressure equipment embrittlement assessment method and related devices, which can accurately determine the material embrittlement degree of the pressure equipment without a hanging block and complete the embrittlement assessment of the pressure equipment.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a method for assessing the embrittlement of pressure-bearing equipment, the method comprising:

[0007] Obtaining first test data at each temperature corresponding to the first sample in different brittle states and second test data at each temperature corresponding to the second sample in different brittle states; the first sample is a sample sampled from a hanging block of the pressure-bearing equipment to be evaluated, and the first test data is test data obtained after a Charpy impact test is performed on the first sample in the brittle state at the temperature, and the first test data includes impact absorption energy and crystalline section rate; the second sample is a sample sampled from the first sample that has completed the test, and the second test data is test data obtained after a small punch test is performed on the second sample in the brittle state at the temperature, and the second test data includes a load-displacement curve and a minimum thickness of the sample;

[0008] For each brittle state, based on the first test data at each temperature corresponding to the first sample in the brittle state, determine the ductile-brittle transition temperature under the Charpy impact test corresponding to the brittle state; based on the second test data at each temperature corresponding to the second sample in the brittle state, determine the ductile-brittle transition temperature under the small punch test corresponding to the brittle state;

[0009] The ductile-brittle transition temperature under the Charpy impact test of different brittle states and the ductile-brittle transition temperature under the small punch test of different brittle states are fitted, and the fitting relationship between the ductile-brittle transition temperature under the Charpy impact test and the ductile-brittle transition temperature under the small punch test is obtained;

[0010] Obtaining third test data at each temperature corresponding to the third sample at the evaluation time, and determining the ductile-brittle transition temperature under the small punch test at the evaluation time based on the third test data at each temperature corresponding to the third sample; the third sample is a sample sampled from a hanging block or a body of the pressure-bearing equipment to be evaluated; the third test data includes a load-displacement curve and a minimum thickness of the sample;

[0011] The ductile-brittle transition temperature under the small punch test at the evaluation time is used as input, and the material embrittlement degree of the pressure-bearing equipment to be evaluated is determined using the fitting relationship.

[0012] In a second aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-mentioned pressure equipment embrittlement assessment method.

[0013] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned pressure equipment embrittlement assessment method.

[0014] In a fourth aspect, the present application provides a computer program product, including a computer program, which implements the above-mentioned pressure equipment embrittlement assessment method when executed by a processor.

[0015] According to the specific embodiments provided in this application, this application has the following technical effects:

[0016] The present application provides a pressure equipment embrittlement assessment method and related devices, which obtain first test data at each temperature corresponding to a first sample in different embrittlement states and second test data at each temperature corresponding to a second sample in different embrittlement states. For each embrittlement state, based on the first test data at each temperature corresponding to the first sample in the embrittlement state, the ductile-brittle transition temperature under the Charpy impact test corresponding to the embrittlement state is determined. Based on the second test data at each temperature corresponding to the second sample in the embrittlement state, the ductile-brittle transition temperature under the small punch test corresponding to the embrittlement state is determined. The ductile-brittle transition temperatures under the Charpy impact test of different embrittlement states and the ductile-brittle transition temperatures under the small punch test of different embrittlement states are fitted to obtain a fitting relationship between the ductile-brittle transition temperature under the Charpy impact test and the ductile-brittle transition temperature under the small punch test. During actual assessment, the third test data at each temperature corresponding to the third sample at the assessment moment is obtained, and based on the third test data at each temperature corresponding to the third sample, the ductile-brittle transition temperature under the small punch test at the assessment moment is determined. The ductile-brittle transition temperature under the small punch test at the assessment moment is used as input, and the material embrittlement of the pressure equipment to be assessed is determined using the fitting relationship. The present application constructs a fitting relationship in advance. During the actual evaluation, since the sample size used in the small punch test is smaller than the sample size used in the Charpy impact test, sampling can be performed directly from the main body of the pressure-bearing equipment. The material embrittlement degree of the pressure-bearing equipment can be accurately determined without a hanging block, thereby completing the embrittlement evaluation of the pressure-bearing equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is an application environment diagram of a pressure equipment embrittlement assessment method provided in Example 1 of the present application.

[0019] Figure 2 A schematic flow chart of a method for assessing embrittlement of pressure-bearing equipment provided in Example 1 of the present application.

[0020] Figure 3 This is a schematic diagram of the relationship curve provided in Example 1 of the present application.

[0021] Figure 4 A schematic diagram of the structure of a computer device provided in Example 2 of the present application. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0023] Example 1

[0024] The pressure equipment embrittlement assessment method provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown, the terminal communicates with the server through the network. The data storage system can store the data that the server needs to process. The data storage system can be set up separately, integrated on the server, or placed on the cloud or other servers. The terminal can send the test data to be processed (including the first test data at each temperature corresponding to the first sample in different brittle states, the second test data at each temperature corresponding to the second sample in different brittle states, and the third test data at each temperature corresponding to the third sample at the evaluation time) to the server. After the server receives the test data to be processed, for each brittle state, the server determines the ductile-brittle transition temperature under the Charpy impact test corresponding to the brittle state based on the first test data at each temperature corresponding to the first sample in the brittle state, and determines the ductile-brittle transition temperature under the small punch test corresponding to the brittle state based on the second test data at each temperature corresponding to the second sample in the brittle state; fits the ductile-brittle transition temperature under the Charpy impact test in different brittle states and the ductile-brittle transition temperature under the small punch test in different brittle states to obtain a fitting relationship between the ductile-brittle transition temperature under the Charpy impact test and the ductile-brittle transition temperature under the small punch test; determines the ductile-brittle transition temperature under the small punch test at the evaluation time based on the third test data at each temperature corresponding to the third sample at the evaluation time; takes the ductile-brittle transition temperature under the small punch test at the evaluation time as input, and determines the material brittleness of the pressure-bearing equipment to be evaluated using the fitting relationship. The server can feed back the obtained material embrittlement degree to the terminal.

[0025] In addition, in some embodiments, the pressure equipment embrittlement assessment method can also be implemented independently by a server or a terminal. For example, the terminal can directly process the test data to be processed, or the server can obtain the test data to be processed from the data storage system and process the test data to be processed.

[0026] The terminals may be, but are not limited to, various desktop computers, laptops, smart phones, tablet computers, IoT devices and portable wearable devices. IoT devices may be smart speakers, smart TVs, smart air conditioners, smart car-mounted devices, etc. Portable wearable devices may be smart watches, smart bracelets, head-mounted devices, etc. The server may be implemented as an independent server or a server cluster consisting of multiple servers, or a cloud server.

[0027] In an exemplary embodiment, Figure 2 As shown, a pressure equipment embrittlement assessment method is provided. The method is executed by a computer device, and can be executed by a computer device such as a terminal or a server alone, or by a terminal and a server together. In the embodiment of the present application, the method is applied to Figure 1 The following steps are used to illustrate the server in the example.

[0028] Step S1, obtaining first test data at each temperature corresponding to a first sample in different brittle states and second test data at each temperature corresponding to a second sample in different brittle states; the first sample is a sample sampled from a hanging block of a pressure-bearing device to be evaluated, and the first test data is test data obtained after a Charpy impact test is performed on the first sample in the brittle state at the temperature, and the first test data includes impact absorption energy and crystalline section rate; the second sample is a sample sampled from a first sample that has completed the test, and the second test data is test data obtained after a small punch test is performed on the second sample in the brittle state at the temperature, and the second test data includes a load-displacement curve and a minimum thickness of the sample.

[0029] Step S2, for each brittle state, based on the first test data at each temperature corresponding to the first sample in the brittle state, determine the ductile-brittle transition temperature under the Charpy impact test corresponding to the brittle state; based on the second test data at each temperature corresponding to the second sample in the brittle state, determine the ductile-brittle transition temperature under the small punch test corresponding to the brittle state.

[0030] Step S3, fitting the ductile-brittle transition temperature under the Charpy impact test in different brittle states and the ductile-brittle transition temperature under the small punch test in different brittle states, and obtaining a fitting relationship between the ductile-brittle transition temperature under the Charpy impact test and the ductile-brittle transition temperature under the small punch test.

[0031] Step S4, obtaining the third test data at each temperature corresponding to the third sample at the evaluation moment, and determining the ductile-brittle transition temperature under the small punch test at the evaluation moment based on the third test data at each temperature corresponding to the third sample; the third sample is a sample sampled from the hanging block or the body of the pressure-bearing equipment to be evaluated; the third test data includes a load-displacement curve and a minimum thickness of the sample.

[0032] Step S5, taking the ductile-brittle transition temperature under the small punch test at the evaluation time as input, and using the fitting relationship to determine the embrittlement degree of the material of the pressure-bearing equipment to be evaluated.

[0033] By implementing the above-mentioned steps S1 to S5, the present embodiment pre-constructs a fitting relationship between the ductile-brittle transition temperature under the Charpy impact test and the ductile-brittle transition temperature under the small punch test. When performing an actual evaluation, a third sample can be sampled from the body of the pressure-bearing equipment to be evaluated to obtain a third sample. Based on the third test data at each temperature corresponding to the third sample, the ductile-brittle transition temperature under the small punch test at the evaluation moment is determined, and the material embrittlement degree of the pressure-bearing equipment to be evaluated is further determined using the fitting relationship. Since the sample size used in the small punch test is small and the damage to the pressure-bearing equipment is small, it belongs to a micro-destructive testing technology, and samples can be directly taken from the body of the pressure-bearing equipment, and the embrittlement of the pressure-bearing equipment can be accurately evaluated without a hanging block.

[0034] As long as the pressure-bearing equipment involves hydrogen embrittlement and temper embrittlement, the pressure-bearing equipment embrittlement assessment method of this embodiment can be used for assessment. For example, the pressure-bearing equipment includes hydrogenation reactors and boilers, etc., to achieve comprehensive characterization of embrittlement damage based on micro-damage testing technology.

[0035] As far as hydrogenation reactors are concerned, since the first hydrogenation reactor was put into operation in the 1980s, more and more hydrogenation reactors have entered or are about to enter the end of their design life. How to inspect and continue to use hydrogenation reactors that have exceeded their service life has become a common focus of regulatory authorities, inspection and testing institutions, and enterprises. Material embrittlement caused by temper embrittlement and hydrogen embrittlement is one of the main damages of hydrogenation reactors after long-term service. From the production point of view, by controlling the temper embrittlement sensitivity coefficients such as the X coefficient and the J coefficient and the step cooling test, only its initial toughness and anti-temper embrittlement performance can be guaranteed. In order to obtain the actual embrittlement performance of the material, it is still necessary to supervise and evaluate the embrittlement performance of the material through regular inspection. The most commonly used method in engineering is to regularly measure the tough-to-brittle transition temperature of the hanging block sample to evaluate the embrittlement degree of the material. As the service time of the hydrogenation reactor increases, it will face the dilemma of no hanging block sample available. In this context, micro-damage testing technology has become the best means to obtain the embrittlement properties of hydrogenation reactor materials. In particular, the small punch test technology (SPT) has made certain progress in the study of mechanical properties such as yield strength, tensile strength, fracture toughness, creep performance, and tough-to-brittle transition temperature of materials. Some research results have also been extended to engineering applications. Based on this, in this embodiment, when there are not enough hanging blocks for in-service pressure-bearing equipment that has exceeded its service life, the small punch test is used to predict the tough-to-brittle transition temperature of the material, and then the embrittlement of the material is evaluated. It is suitable for the evaluation of suitability for use under damage modes such as embrittlement of chromium-molybdenum steel in hydrogenation reactors. Other pressure-bearing equipment with the same embrittlement mechanism can also be used as a reference, such as boilers.

[0036] Among them, the ductile-brittle transition temperature means: when the test temperature is lower than a certain transition temperature, the fracture mode of body-centered cubic structure and some close-packed hexagonal metals and their alloy materials changes from ductile fracture to brittle fracture, that is, low-temperature brittle phenomenon occurs. The transition temperature at this time is called the ductile-brittle transition temperature, also known as the cold brittle transition temperature.

[0037] In this embodiment, constructing the fitting relationship includes the following steps:

[0038] (1) Obtaining first test data at each temperature corresponding to a first sample in a different brittle state and second test data at each temperature corresponding to a second sample in a different brittle state.

[0039] Among them, the embrittled state may include: taken-out state, de-embrittled state, step-cooling state, etc.

[0040] In order to obtain the first specimens in different embrittlement states, during each overhaul of the pressure-bearing equipment, random samples are taken from the hanging blocks of the pressure-bearing equipment to obtain the first specimens. The first specimens during different overhauls are the first specimens in different embrittlement states. Of course, different embrittlement states can also be artificially prefabricated, and random samples are taken from the hanging blocks of the pressure-bearing equipment to obtain specimens, and then the specimens are processed to obtain the first specimens in different embrittlement states, wherein a debrittle state is obtained by using a debrittle state treatment process, and the debrittle state is obtained by raising the temperature from room temperature to 650°C within 1 hour, keeping the temperature at 650°C for 2 hours, and then taking out and air cooling, and a step cooling process is used to obtain a step cooling state. The step cooling process can be based on S63.2 in ASME SA-542 / SA-542M to rapidly embrittle the material in a short time. Of course, the above two methods can also be combined to obtain the first specimens in different embrittlement states.

[0041] In order to obtain a second specimen in a different brittle state, a thin slice is cut from the first specimen that has completed the test and processed into a small punch rod specimen to obtain a second specimen in a different brittle state, wherein the first specimen that has completed the test refers to the first specimen that has completed tests such as the Charpy impact test, the tensile test or the fracture toughness test. Of course, a sample can also be taken from the hanging block of the pressure-bearing equipment to obtain a specimen, and then the specimen is processed to obtain a second specimen in a different brittle state. Of course, the above two methods can also be combined to obtain a second specimen in a different brittle state.

[0042] When preparing the second sample, the sample was processed into a 10mm×10mm columnar block, and then processed into a thin slice of about 0.75mm by wire cutting. The size of the slice was 10mm×10mm×0.75mm. A double-sided grinder was used to grind the slice to 0.6mm to eliminate the surface processing lines. Finally, the slice was manually fine-ground to 0.5mm±0.005mm with 1000# or higher sandpaper. The slice at this time was the second sample.

[0043] The temperature range of the Charpy impact test and the small punch test is -196°C to room temperature. At least 7 temperature points are selected within this temperature range. Each temperature point can correspond to 3 specimens (the first specimen and the second specimen). It is recommended that the selected temperature points be located in the low temperature zone as much as possible to determine multiple different temperatures.

[0044] For each temperature, a Charpy impact test is carried out at the temperature. For each first sample in a brittle state, a first sample with a certain shape and size is specifically prepared so that it has a U-shaped notch or a V-shaped notch. It is in a simply supported beam state on a Charpy impact tester. The pendulum lifted by the Charpy impact tester is used to make an impact so that the first sample is broken along the notch. The first test data is measured and obtained. The first test data includes impact absorption energy and crystalline section rate.

[0045] For each temperature, a small punch test is performed at that temperature. For each second sample in a brittle state, the edge of the second sample is fixed, and the spherical punch at the top of the punch is used to load the center of the second sample. During the test, the loading rate is controlled within the range of 0.2mm / min to 0.5mm / min. When a 20% stress drop occurs after the load exceeds the peak value, the test can be stopped. The second test data is measured and obtained. The second test data includes the duration of the test, the load-displacement curve and the minimum thickness of the sample. The load is the mechanical force applied by the punch to the sample, the displacement is the displacement value of the punch, the load-displacement curve is the relationship curve between the load and the displacement formed in the small punch test, and the minimum thickness of the sample is the minimum value of the thickness of the second sample when the test is stopped. The specific test procedure of the small punch test can refer to GB / T 29459.2-2012 Small punch test method for metal materials of in-service pressure equipment Part 2: Test method for tensile properties at room temperature.

[0046] Through the above process, this embodiment can perform Charpy impact test and small punch test at different temperatures for each brittle state, and obtain first test data at each temperature corresponding to the first sample in different brittle states and second test data at each temperature corresponding to the second sample in different brittle states.

[0047] (2) For each brittle state, the ductile-brittle transition temperature under the Charpy impact test corresponding to the brittle state is determined based on the first test data at each temperature corresponding to the first specimen in the brittle state; and the ductile-brittle transition temperature under the small punch test corresponding to the brittle state is determined based on the second test data at each temperature corresponding to the second specimen in the brittle state.

[0048] Based on the first test data at each temperature corresponding to the first sample in the brittle state, determining the ductile-brittle transition temperature under the Charpy impact test corresponding to the brittle state specifically includes:

[0049] 1) The impact absorption energy at each temperature corresponding to the first sample in the brittle state is fitted to obtain a first relationship curve between the impact absorption energy and temperature, and the temperature corresponding to the impact absorption energy of 54 J and the temperature corresponding to the average of the upper and lower platforms of the impact absorption energy are determined based on the first relationship curve. The first relationship curve uses temperature as the abscissa and the impact absorption energy as the ordinate.

[0050] 2) Fit the crystalline cross-section ratio at each temperature corresponding to the first sample in the brittle state to obtain a second relationship curve between the crystalline cross-section ratio and temperature, and determine the temperature corresponding to the crystalline cross-section ratio of 50% based on the second relationship curve. The second relationship curve uses temperature as the horizontal coordinate and the crystalline cross-section ratio as the vertical coordinate.

[0051] 3) At least one of the temperature corresponding to an impact absorption energy of 54 J, the temperature corresponding to the average of the upper and lower platforms of the impact absorption energy, and the temperature corresponding to a crystalline section ratio of 50% is selected to constitute the ductile-brittle transition temperature under the Charpy impact test.

[0052] In this embodiment, a Charpy impact test is performed on first samples in different brittle states, and the first test data obtained are processed to obtain the ductile-brittle transition temperatures VTr54, FATT and DBTT of the first samples in different brittle states, where VTr54 represents the temperature corresponding to an impact absorption energy of 54 J, FATT represents the temperature corresponding to a crystalline section rate of 50%, and DBTT represents the temperature corresponding to the average of the upper and lower platforms of the impact absorption energy.

[0053] Each second sample in the brittle state includes second samples in different notched states, that is, the second test data at each temperature corresponding to the second sample in the brittle state includes the second test data at each temperature corresponding to the second sample in each notched state in the brittle state. The notched state includes notch types when there is no notch and notch, and the notch types include circular, cross and linear shapes. For the second sample with notch, a laser marking machine can be used to process notches of different shapes with constant parameters, for example, a notch with a diameter of A circular notch with a depth of 0.2mm, a cross-shaped notch of 4×4mm and a depth of 0.2mm, a linear notch with a width of 0.5mm and a depth of 0.2mm, etc.

[0054] At this time, based on the second test data at each temperature corresponding to the second sample in the brittle state, the ductile-brittle transition temperature under the small punch test corresponding to the brittle state is determined, specifically including:

[0055] 1) For each notch state, based on the second test data at each temperature corresponding to the second specimen in the notch state in the brittle state, each fracture characterization parameter at each temperature corresponding to the second specimen in the notch state in the brittle state is calculated, and the fracture characterization parameters are fracture energy, normalized fracture energy, equivalent fracture strain and thickness reduction rate.

[0056] 2) For each fracture characterization parameter corresponding to each notch state, the fracture characterization parameter at each temperature corresponding to the second sample in the notch state of the brittle state is fitted to obtain a third relationship curve between the fracture characterization parameter and temperature, and the ductile-brittle transition temperature under the small punch test is determined based on the third relationship curve. The third relationship curve uses temperature as the horizontal coordinate and the fracture characterization parameter as the vertical coordinate.

[0057] In this embodiment, a small punch test is performed on the second specimens in different brittle states, and the obtained second test data is processed to obtain the ductile-brittle transition temperature of the second specimen in different brittle states corresponding to each notch state and each fracture characterization parameter. The ductile-brittle transition temperature of the second specimen can be selected as the temperature corresponding to the average of the upper and lower platforms of the fracture characterization parameter. If the notch state includes 4 types and the fracture characterization parameter includes 8 types, then the ductile-brittle transition temperature of the second specimen in different brittle states corresponding to each notch state and each fracture characterization parameter includes 32 types.

[0058] The calculation of fracture characterization parameters is as follows:

[0059] 1) Fracture energy

[0060] The calculation formula of fracture energy is:

[0061]

[0062] Among them, E sp is the fracture energy; u f is the displacement at the end of the small punch test, that is, the displacement when a 20% stress drop occurs after the load reaches the peak value, which can be called the fracture displacement; F is the load; u is the displacement.

[0063] 2) Normalization of fracture energy

[0064] When normalizing the fracture energy, the influence of factors such as the original thickness of the sample, peak load, peak deflection, and minimum thickness of the sample are comprehensively considered. Combined with dimensional analysis, the fracture energy is normalized. The calculation formula of the normalized fracture energy is:

[0065]

[0066] in, is the first normalized fracture energy; F m is the peak load.

[0067]

[0068] in, is the second normalized fracture energy; h 0 is the original thickness of the specimen.

[0069]

[0070] in, is the third normalized fracture energy.

[0071]

[0072] in, is the fourth normalized fracture energy; um It is the peak deflection, that is, the deflection corresponding to the peak load, which can be read directly from the testing machine for the small punch test.

[0073]

[0074] in, is the fifth normalized fracture energy.

[0075] The first normalized fracture energy, the second normalized fracture energy, the third normalized fracture energy, the fourth normalized fracture energy and the fifth normalized fracture energy constitute the normalized fracture energy.

[0076] 3) Equivalent fracture strain

[0077] The calculation formula of equivalent fracture strain is:

[0078] ε q =ln(h 0 / h f );

[0079] Among them, ε q is the equivalent fracture strain; h f It is the minimum thickness of the specimen, that is, the thickness of the specimen at the maximum thinning point at the end of the small punch test.

[0080] 4)Thickness reduction rate

[0081] The calculation formula of thickness reduction rate is:

[0082]

[0083] Where n is the thickness reduction rate.

[0084] When determining the ductile-brittle transition temperature, this embodiment performs relationship curve fitting, and determines the ductile-brittle transition temperature through the relationship curve obtained by fitting.

[0085] Fitting the impact absorption energy at each temperature corresponding to the first sample in the brittle state specifically includes: fitting the impact absorption energy at each temperature corresponding to the first sample in the brittle state based on a preset function.

[0086] The crystalline cross-section ratio at each temperature corresponding to the first sample in the brittle state is fitted, specifically comprising: fitting the crystalline cross-section ratio at each temperature corresponding to the first sample in the brittle state based on a preset function.

[0087] The fracture characterization parameters at each temperature corresponding to the second sample in the notched state in the brittle state are fitted, specifically including: fitting the fracture characterization parameters at each temperature corresponding to the second sample in the notched state in the brittle state based on a preset function.

[0088] Among them, the preset function is the Boltzmann function, the hyperbolic tangent function or the Logistic function.

[0089] When the Boltzmann function form is used for fitting, the first relationship curve, the second relationship curve and the third relationship curve obtained by fitting are all as follows Figure 3 As shown, the overall shape is "S", with four parameters: upper platform (the ordinate corresponding to the straight line with a larger ordinate), lower platform (the ordinate corresponding to the straight line with a smaller ordinate), the half-width CR of the ductile-brittle transition zone (determine the tangent line on the relationship curve passing through the ductile-brittle transition temperature point, the distance from the intersection of the straight line where the lower platform is located and the tangent line to the ductile-brittle transition temperature point is the half-width of the ductile-brittle transition zone, or the distance from the intersection of the straight line where the upper platform is located and the tangent line to the ductile-brittle transition temperature point is the half-width of the ductile-brittle transition zone) and the ductile-brittle transition temperature T 0 , which can be specifically fitted through commercial statistical analysis software, such as origin. When fitting with the Boltzmann function, given that the relationship curve has obvious upper and lower platforms, it is recommended to first fix the upper and lower platforms during fitting, and then iterate until convergence to obtain the relationship curve, and further determine the ductile-brittle transition temperature. Among them, the straight line refers to a straight line composed of data points with the same ordinate.

[0090] (3) The ductile-brittle transition temperature under the Charpy impact test with different brittle states and the ductile-brittle transition temperature under the small punch test with different brittle states were fitted to obtain the fitting relationship between the ductile-brittle transition temperature under the Charpy impact test and the ductile-brittle transition temperature under the small punch test.

[0091] In this example, the ductile-brittle transition temperature T sp(i) Regression with VTr54, FATT, and DBTT, with T sp(i) As the horizontal coordinate, VTr54, FATT, and DBTT are used as the vertical coordinates, and linear fitting is performed according to the least squares method to establish the following initial relationship:

[0092] Vtr54=R 1(i) T sp(i) +b 1(i) ;

[0093] FATT=R 2(i) T sp(i) +b 2(i) ;

[0094] DBTT=R 3(i) T sp(i) +b 3(i) ;

[0095] Among them, i represents different notch states and different fracture characterization parameters; R 1(i) 、b 1(i) , R 2(i) 、b 2(i) , R 3(i) and b 3(i) are fitting parameters.

[0096] According to the fitting results, the initial relationship with a Pearson correlation coefficient ≥ 0.7 and only one Boltzmann function fitting is required, and the screened relationship with the highest correlation coefficient is selected as the fitting relationship for estimating the ductile-brittle transition temperature of the pressure-bearing equipment material. At the same time, the optimal sample form and the optimal fracture characterization parameters are determined. The notch state corresponding to the fitting relationship is the optimal sample form, and the fracture characterization parameters corresponding to the fitting relationship are the optimal fracture characterization parameters.

[0097] Through the above process, the correlation between the ductile-brittle transition temperature under the small punch test and the ductile-brittle transition temperature under the Charpy impact test is established, and then the conventional ductile-brittle transition temperature of the material (i.e., the ductile-brittle transition temperature under the Charpy impact test) can be estimated based on the test results of the small punch test.

[0098] At this time, the ductile-brittle transition temperature under the Charpy impact test in different brittle states and the ductile-brittle transition temperature under the small punch test in different brittle states are fitted to obtain the fitting relationship between the ductile-brittle transition temperature under the Charpy impact test and the ductile-brittle transition temperature under the small punch test, which specifically includes:

[0099] 1) For each fracture characterization parameter corresponding to each notch state, the ductile-brittle transition temperature under the Charpy impact test with different brittle states and the ductile-brittle transition temperature under the small punch test with different brittle states corresponding to the notch state and fracture characterization parameter are fitted to obtain the initial relationship between the ductile-brittle transition temperature under the Charpy impact test and the ductile-brittle transition temperature under the small punch test.

[0100] For each fracture characterization parameter corresponding to each notch state, the ductile-brittle transition temperature under the Charpy impact test and the ductile-brittle transition temperature under the small punch test in the same brittle state are taken as a data point, the ductile-brittle transition temperature under the small punch test is taken as the horizontal coordinate, and the ductile-brittle transition temperature under the Charpy impact test is taken as the vertical coordinate. All data points are fitted to obtain the initial relationship.

[0101] The ductile-brittle transition temperature under the Charpy impact test in different brittle states and the ductile-brittle transition temperature under the small punch test in different brittle states corresponding to the notch state and fracture characterization parameters are fitted, specifically including: using the least squares method to linearly fit the ductile-brittle transition temperature under the Charpy impact test in different brittle states and the ductile-brittle transition temperature under the small punch test in different brittle states corresponding to the notch state and fracture characterization parameters.

[0102] 2) Screen all initial relationship equations and determine the fitting relationship equation.

[0103] Screening all initial relationship equations to determine a fitting relationship equation, specifically including: screening all initial relationship equations according to a preset principle to obtain a screened relationship equation, the preset principle being that the correlation coefficient is greater than or equal to a preset value, and the third relationship curve corresponding to the ductile-brittle transition temperature under the small punch test in the initial relationship equation is obtained by fitting only once; selecting the screened relationship equation with the highest correlation coefficient as the fitting relationship equation.

[0104] Only one fitting is required means that an S-shaped curve with an upper platform and a lower platform can be obtained by only one fitting. If segmented fitting is required, or the data points are distributed irregularly and the relationship curve cannot be fitted, then only one fitting is no longer required.

[0105] After constructing the fitting relationship, since the fitting relationship characterizes the correlation between the ductile-brittle transition temperature under the small punch test and the ductile-brittle transition temperature under the Charpy impact test, this embodiment can use the test results of the small punch test to estimate the ductile-brittle transition temperature of the pressure-bearing equipment after long-term service. The difference between the ductile-brittle transition temperatures of two adjacent evaluations is the material brittleness, thereby completing the material brittleness calculation.

[0106] In this embodiment, the evaluation process specifically includes the following steps:

[0107] (1) Obtaining third test data at each temperature corresponding to the third sample at the evaluation time, and determining the ductile-brittle transition temperature under the small punch test at the evaluation time based on the third test data at each temperature corresponding to the third sample.

[0108] When sampling, the third sample can be sampled from the hanging block of the pressure-bearing equipment. If the hanging block has been used up, the third sample can also be sampled directly from the body of the pressure-bearing equipment using an electric spark sampler or a mechanical sampler, and then the body of the pressure-bearing equipment is welded. The sampling depth is determined according to user needs.

[0109] Preferably, the third sample selects the best sample form, that is, the notch state of the third sample adopts the notch state corresponding to the fitting relationship. The preparation method of the third sample is the same as the preparation method of the second sample.

[0110] At different temperatures, a small punch test is performed on the third sample to obtain third test data, which includes a load-displacement curve and a minimum thickness of the sample.

[0111] Based on the third test data at each temperature corresponding to the third sample, the ductile-brittle transition temperature under the small punch test at the evaluation time is determined, specifically including:

[0112] 1) Based on the third test data at each temperature corresponding to the third sample, the fracture characterization parameter for evaluation at each temperature corresponding to the third sample is calculated, and the fracture characterization parameter for evaluation adopts the fracture characterization parameter corresponding to the fitting relationship.

[0113] 2) Fitting the fracture characterization parameters for evaluation at each temperature corresponding to the third sample to obtain a fourth relationship curve between the fracture characterization parameters for evaluation and temperature, and determining the ductile-brittle transition temperature under the small punch test at the evaluation moment based on the fourth relationship curve.

[0114] (2) The ductile-brittle transition temperature under the small punch test at the evaluation time is used as input, and the brittleness of the material of the pressure-bearing equipment to be evaluated is determined using the fitting relationship.

[0115] The pressure equipment embrittlement assessment method of this embodiment has the following advantages:

[0116] (1) Micro-damage. Compared with the ductile-brittle transition temperature determined by the conventional Charpy impact test, this method only needs to take samples from the Charpy impact specimens, tensile specimens or fracture toughness specimens that have completed the test, or take a small amount of samples from the hanging block of the pressure-bearing equipment, to construct a fitting relationship. Subsequently, a small amount of samples are taken from the hanging block of the pressure-bearing equipment or a small amount of samples are taken from the body of the pressure-bearing equipment, and the ductile-brittle transition temperature can be obtained using the fitting relationship.

[0117] (2) High precision. This method comprehensively considers factors such as peak load, peak deflection, original thickness of the specimen, and minimum thickness of the specimen. Through normalization processing, it can obtain the ductile-brittle transition temperature under the small punch test with only one curve fitting, avoiding the interference of human factors caused by traditional segmented fitting and improving the fitting accuracy. The correlation between the ductile-brittle transition temperature of the small punch with different notch states and different fracture characterization parameters and the conventional ductile-brittle transition temperature is compared and analyzed, and the one with the highest correlation coefficient is selected as the fitting relationship for estimating the conventional ductile-brittle transition temperature of the pressure-bearing equipment material, and the optimal specimen form and the optimal fracture characterization parameters are determined, thereby improving the fitting accuracy.

[0118] The present application also provides an application scenario, which applies the above-mentioned pressure equipment embrittlement assessment method. Specifically, the pressure equipment embrittlement assessment method provided in this embodiment can be applied in the embrittlement assessment scenario. The embrittlement assessment scenario includes a data acquisition link, a data processing link and a result display link. The data acquisition link is used to acquire test data, the data processing link is used to process the test data to obtain the material embrittlement degree, and the result display link is used to display the material embrittlement degree. The pressure equipment embrittlement assessment method provided in this embodiment belongs to the data processing link.

[0119] Example 2

[0120] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Figure 4 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for assessing the embrittlement of pressure-bearing equipment is implemented.

[0121] Those skilled in the art will understand that Figure 4 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0122] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the pressure equipment embrittlement assessment method in Example 1 when executing the computer program.

[0123] Example 3

[0124] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, which implements the pressure equipment embrittlement assessment method in Example 1 when executed by a processor.

[0125] Example 4

[0126] In an exemplary embodiment, a computer program product is provided, including a computer program, which implements the pressure equipment embrittlement assessment method in Example 1 when executed by a processor.

[0127] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0128] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0129] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for assessing embrittlement of pressure equipment, characterized in that: The pressure equipment embrittlement assessment method comprises: Obtaining first test data at each temperature corresponding to the first sample in different brittle states and second test data at each temperature corresponding to the second sample in different brittle states; the first sample is a sample sampled from a hanging block of the pressure-bearing equipment to be evaluated, and the first test data is test data obtained after a Charpy impact test is performed on the first sample in the brittle state at the temperature, and the first test data includes impact absorption energy and crystalline section rate; the second sample is a sample sampled from the first sample that has completed the test, and the second test data is test data obtained after a small punch test is performed on the second sample in the brittle state at the temperature, and the second test data includes a load-displacement curve and a minimum thickness of the sample; For each brittle state, based on the first test data at each temperature corresponding to the first sample in the brittle state, determine the ductile-brittle transition temperature under the Charpy impact test corresponding to the brittle state; based on the second test data at each temperature corresponding to the second sample in the brittle state, determine the ductile-brittle transition temperature under the small punch test corresponding to the brittle state; The ductile-brittle transition temperature under the Charpy impact test of different brittle states and the ductile-brittle transition temperature under the small punch test of different brittle states are fitted, and the fitting relationship between the ductile-brittle transition temperature under the Charpy impact test and the ductile-brittle transition temperature under the small punch test is obtained; Obtaining third test data at each temperature corresponding to the third sample at the evaluation time, and determining the ductile-brittle transition temperature under the small punch test at the evaluation time based on the third test data at each temperature corresponding to the third sample; the third sample is a sample sampled from a hanging block or a body of the pressure-bearing equipment to be evaluated; the third test data includes a load-displacement curve and a minimum thickness of the sample; The ductile-brittle transition temperature under the small punch test at the evaluation time is used as input, and the material embrittlement degree of the pressure-bearing equipment to be evaluated is determined using the fitting relationship.

2. The pressure equipment embrittlement assessment method according to claim 1, characterized in that: Based on the first test data at each temperature corresponding to the first sample in the brittle state, determining the ductile-brittle transition temperature under the Charpy impact test corresponding to the brittle state specifically includes: The impact absorption energy at each temperature corresponding to the first sample in the brittle state is fitted to obtain a first relationship curve between the impact absorption energy and the temperature, and based on the first relationship curve, the temperature corresponding to the impact absorption energy of 54 J and the temperature corresponding to the average of the upper and lower platforms of the impact absorption energy are determined; the first relationship curve uses the temperature as the abscissa and the impact absorption energy as the ordinate; Fitting the crystalline cross-section ratio at each temperature corresponding to the first sample in the brittle state to obtain a second relationship curve between the crystalline cross-section ratio and the temperature, and determining the temperature corresponding to the crystalline cross-section ratio of 50% based on the second relationship curve; the second relationship curve takes the temperature as the abscissa and the crystalline cross-section ratio as the ordinate; At least one of the temperature corresponding to an impact absorption energy of 54 J, the temperature corresponding to the average of the upper and lower platforms of the impact absorption energy, and the temperature corresponding to a crystalline section rate of 50% is selected to constitute the ductile-brittle transition temperature under the Charpy impact test.

3. The pressure equipment embrittlement assessment method according to claim 2, characterized in that: The second test data at each temperature corresponding to the second sample in the brittle state includes the second test data at each temperature corresponding to the second sample in each notched state in the brittle state. At this time, based on the second test data at each temperature corresponding to the second sample in the brittle state, the ductile-brittle transition temperature under the small punch test corresponding to the brittle state is determined, specifically including: For each notch state, based on the second test data at each temperature corresponding to the second sample in the notch state in the brittle state, each fracture characterization parameter at each temperature corresponding to the second sample in the notch state in the brittle state is calculated; the fracture characterization parameters are fracture energy, normalized fracture energy, equivalent fracture strain and thickness reduction rate; For each fracture characterization parameter corresponding to each notch state, the fracture characterization parameter at each temperature corresponding to the second sample in the notch state in the brittle state is fitted to obtain a third relationship curve between the fracture characterization parameter and temperature, and the ductile-brittle transition temperature under the small punch test is determined based on the third relationship curve; the third relationship curve uses temperature as the horizontal coordinate and the fracture characterization parameter as the vertical coordinate.

4. The pressure equipment embrittlement assessment method according to claim 3, characterized in that: The calculation formula of fracture energy is: Among them, E sp is the fracture energy; u f is the displacement at the end of the small punch test; F is the load; u is the displacement; The calculation formula of normalized fracture energy is: in, is the first normalized fracture energy; F m is the peak load; in, is the second normalized fracture energy; h0 is the original thickness of the sample; in, is the third normalized fracture energy; in, is the fourth normalized fracture energy; u m is the peak deflection; in, is the fifth normalized fracture energy; The first normalized fracture energy, the second normalized fracture energy, the third normalized fracture energy, the fourth normalized fracture energy and the fifth normalized fracture energy constitute the normalized fracture energy; The calculation formula of equivalent fracture strain is: e q =ln(h0 / h f ); Among them, ε q is the equivalent fracture strain; h f is the minimum thickness of the specimen; The calculation formula of thickness reduction rate is: Where n is the thickness reduction rate.

5. The pressure equipment embrittlement assessment method according to claim 3, characterized in that: Fitting the impact absorption energy at each temperature corresponding to the first sample in the brittle state, specifically comprising: fitting the impact absorption energy at each temperature corresponding to the first sample in the brittle state based on a preset function; Fitting the crystalline cross-section ratio at each temperature corresponding to the first sample in the brittle state, specifically comprising: fitting the crystalline cross-section ratio at each temperature corresponding to the first sample in the brittle state based on a preset function; Fitting the fracture characterization parameter at each temperature corresponding to the second sample in the notched state in the brittle state, specifically comprising: fitting the fracture characterization parameter at each temperature corresponding to the second sample in the notched state in the brittle state based on a preset function; Wherein, the preset function is a Boltzmann function, a hyperbolic tangent function or a Logistic function.

6. The pressure equipment embrittlement assessment method according to claim 3, characterized in that: The ductile-brittle transition temperature under the Charpy impact test in different brittle states and the ductile-brittle transition temperature under the small punch test in different brittle states are fitted to obtain the fitting relationship between the ductile-brittle transition temperature under the Charpy impact test and the ductile-brittle transition temperature under the small punch test, including: For each fracture characterization parameter corresponding to each notch state, the ductile-brittle transition temperature under the Charpy impact test in different brittle states and the ductile-brittle transition temperature under the small punch test in different brittle states corresponding to the notch state and the fracture characterization parameter are fitted to obtain an initial relationship between the ductile-brittle transition temperature under the Charpy impact test and the ductile-brittle transition temperature under the small punch test; Screening all the initial relational expressions to determine a fitting relational expression; Among them, the ductile-brittle transition temperature under the Charpy impact test in different brittle states and the ductile-brittle transition temperature under the small punch test in different brittle states corresponding to the notch state and the fracture characterization parameter are fitted, specifically including: using the least squares method to linearly fit the ductile-brittle transition temperature under the Charpy impact test in different brittle states and the ductile-brittle transition temperature under the small punch test in different brittle states corresponding to the notch state and the fracture characterization parameter; Among them, screening all the initial relationship equations to determine the fitting relationship equation specifically includes: All the initial relational expressions are screened according to a preset principle to obtain a screened relational expression; the preset principle is that the correlation coefficient is greater than or equal to a preset value, and the third relational curve corresponding to the ductile-brittle transition temperature under the small punch test in the initial relational expression is obtained by fitting only once; The screening relationship with the highest correlation coefficient is selected as the fitting relationship.

7. The pressure equipment embrittlement assessment method according to claim 6, characterized in that: The notch state of the third sample adopts the notch state corresponding to the fitting relationship. At this time, based on the third test data at each temperature corresponding to the third sample, the ductile-brittle transition temperature under the small punch test at the evaluation time is determined, specifically including: Based on the third test data at each temperature corresponding to the third sample, the fracture characterization parameter for evaluation at each temperature corresponding to the third sample is calculated; the fracture characterization parameter for evaluation adopts the fracture characterization parameter corresponding to the fitting relationship; The fracture characterization parameters for evaluation at each temperature corresponding to the third sample are fitted to obtain a fourth relationship curve between the fracture characterization parameters for evaluation and temperature, and the ductile-brittle transition temperature under the small punch test at the evaluation moment is determined based on the fourth relationship curve.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the pressure equipment embrittlement assessment method according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for assessing the embrittlement of pressure-bearing equipment described in any one of claims 1 to 7 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for assessing the embrittlement of pressure-bearing equipment described in any one of claims 1 to 7 is implemented.

Images