Methods for determining loss parameters and metal material processing systems

Abstract

This application discloses a method for determining fracture parameters and a metal material processing system, belonging to the field of metal material technology. The method includes: preparing a metal material sample; conducting a room temperature fatigue crack propagation test on the metal material sample until the sample fractures; using a scanning electron microscope in secondary electron imaging mode to photograph the fatigue fracture surface of the metal material sample, obtaining a fracture surface image; determining the fracture length and corresponding stress intensity factor at multiple marked locations in the fracture surface image; identifying the target location exhibiting complete intergranular fracture characteristics from the fracture surface image, and determining the stress intensity factor corresponding to the target location as the inflection point stress intensity factor; determining the fracture parameters of the metal material sample, wherein the fracture parameters are positively correlated with the inflection point stress intensity factor, material parameters, and initial stress intensity factor. This method is simple in principle, provides high accuracy in evaluation results, and is convenient and easy to implement.

Description

Technical Field

[0001] This application relates to the field of metal materials technology, and in particular to a method for determining breakage parameters and a metal material processing system. Background Technology

[0002] Damage to metallic materials is a slow, cumulative process. Once the damage accumulates to a certain extent, it leads to the initiation and gradual propagation of micropores or microcracks, ultimately causing the metallic material to fracture and fail. If the extent of accumulated damage cannot be predicted in time, it poses a significant threat to the safe operation of equipment. Therefore, assessing the degree of damage and remaining life of metallic materials is of paramount importance.

[0003] Metal fatigue fracture is a common failure mode in engineering. Currently, empirical formulas or computational simulations are often used to predict the remaining life of metallic materials. However, due to the complex and variable service environment and working load, the solution accuracy of fatigue prediction models is difficult to guarantee, resulting in inaccurate prediction results. Summary of the Invention

[0004] This application provides a method for determining breakage parameters and a metal material processing system, offering a method for accurately evaluating the breakage parameters of metal materials. The method is simple in principle and provides highly accurate evaluation results. The technical solution is as follows:

[0005] On the one hand, a method for determining loss parameters is provided, the method comprising:

[0006] Prepare a metal material sample and conduct a room temperature fatigue crack propagation test on the metal material sample until the metal material sample fractures.

[0007] The fatigue fracture surface of the metal material sample was photographed using a scanning electron microscope in secondary electron imaging mode to obtain fracture surface images.

[0008] Determine the fracture length and corresponding stress intensity factor at multiple marked locations in the fracture image;

[0009] From the fracture image, determine the target location that exhibits complete intergranular fracture characteristics, and determine the stress intensity factor corresponding to the target location as the inflection point stress intensity factor;

[0010] Based on the inflection point stress intensity factor, the material parameters, and the initial stress intensity factor of the metal material sample, the breakage parameter of the metal material sample is determined. The breakage parameter is positively correlated with the inflection point stress intensity factor, the material parameters, and the initial stress intensity factor.

[0011] In another possible implementation, the step of using a scanning electron microscope in a secondary electron imaging mode to photograph the fatigue fracture surface of the metallic material sample to obtain a fracture surface image includes:

[0012] Using the scanning electron microscope and the secondary electron imaging mode, images are taken from the starting position of the fatigue fracture along the crack propagation direction until the end position of the fatigue fracture, resulting in multiple fracture images.

[0013] Multiple fracture images captured are stitched together to obtain a stitched fracture image.

[0014] In another possible implementation, the step of using a scanning electron microscope in a secondary electron imaging mode to photograph the fatigue fracture surface of the metallic material sample to obtain a fracture surface image includes:

[0015] Using the scanning electron microscope and the secondary electron imaging mode, the fatigue fracture surface of the metal material sample is photographed from at least two fields of view to obtain at least two fracture surface images.

[0016] In another possible implementation, the method further includes:

[0017] After determining the inflection point stress intensity factor corresponding to the at least two fracture images, the average value of the inflection point stress intensity factor corresponding to the at least two fracture images is determined as the inflection point stress intensity factor of the metallic material sample.

[0018] In another possible implementation, determining the breakage parameter of the metal material specimen based on the inflection point stress intensity factor, the material parameters of the metal material specimen, and the initial stress intensity factor, wherein the breakage parameter is positively correlated with the inflection point stress intensity factor, the material parameters, and the initial stress intensity factor, includes:

[0019] The loss parameter is determined using the following formula, based on the inflection point stress intensity factor, the material parameters, and the initial stress intensity factor:

[0020]

[0021] Where δ is the loss parameter, ΔK T Let ΔK be the stress intensity factor at the inflection point. i denoted as the initial stress intensity factor, and m as the material parameter.

[0022] In another possible implementation, the fabrication of the metallic material sample includes:

[0023] A metal material sample is longitudinally cut from the root of the turbine blade, and pre-made cracks are made transversely on the metal material sample.

[0024] On the other hand, a metal material processing system is provided, the system including a sample preparation device, a fatigue crack propagation testing machine, a scanning electron microscope and a computer device;

[0025] The sample preparation device is used to prepare metallic material samples;

[0026] The fatigue crack propagation testing machine is used to perform room temperature fatigue crack propagation tests on the metal material specimen until the metal material specimen fractures.

[0027] The scanning electron microscope is used to photograph the fatigue fracture surface of the metal material sample using a secondary electron imaging mode to obtain a fracture surface image.

[0028] The computer device is used to determine the fracture length and corresponding stress intensity factor at multiple marked locations in the fracture image; to determine the target location exhibiting complete intergranular fracture characteristics from the fracture image, and to determine the stress intensity factor corresponding to the target location as the inflection point stress intensity factor; and to determine the breakage parameter of the metal material sample based on the inflection point stress intensity factor, the material parameters of the metal material sample, and the initial stress intensity factor, wherein the breakage parameter is positively correlated with the inflection point stress intensity factor, the material parameters, and the initial stress intensity factor.

[0029] In one possible implementation, the scanning electron microscope is used to take pictures from the starting position of the fatigue fracture along the crack propagation direction using the secondary electron imaging mode until the ending position of the fatigue fracture, thereby obtaining multiple fracture images.

[0030] The computer device is used to stitch together multiple captured fracture images to obtain a stitched fracture image.

[0031] In another possible implementation, the scanning electron microscope is used to take pictures of the fatigue fracture surface of the metallic material sample from at least two fields of view using the secondary electron imaging mode, thereby obtaining at least two fracture surface images.

[0032] In another possible implementation, the sample preparation device is used to longitudinally cut a metal material sample from the root of the turbine blade and to transversely cut pre-made cracks on the metal material sample.

[0033] The beneficial effects of the technical solutions provided in this application include at least the following:

[0034] In this embodiment, the stress intensity factor at the inflection point where the fatigue fracture surface exhibits complete intergranular fracture characteristics accurately reflects the degree of damage accumulation in the metallic material during service. Therefore, the stress intensity factor at the inflection point is used as the evaluation basis. Based on the stress intensity factor at the inflection point of the metallic material sample, the material parameters of the metallic material sample, and the initial stress intensity factor, the breakage parameter of the metallic material sample is determined. The breakage parameter is positively correlated with the stress intensity factor at the inflection point, the material parameters, and the initial stress intensity factor, thus using the breakage parameter to represent the degree of life loss of the metallic material. Compared with the methods of predicting remaining life using empirical formulas or computational simulations in related technologies, this embodiment can obtain the data required to evaluate the accumulated damage in the metallic material, without requiring a crack propagation monitoring process. The evaluation method is simple in principle, has high accuracy in evaluation results, and is convenient and easy to implement, facilitating engineering application and promotion. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a flowchart of a method for determining loss parameters provided in an embodiment of this application;

[0037] Figure 2 This is a schematic diagram of cutting a metal material sample according to an embodiment of this application;

[0038] Figure 3 This is a schematic diagram of a sample size provided in an embodiment of this application;

[0039] Figure 4 This is a schematic diagram showing the stress intensity factor and fracture length calibrated in a fracture image provided in an embodiment of this application;

[0040] Figure 5 This is a schematic diagram showing the stress intensity factor and fracture length calibrated in another fracture image provided in this application embodiment. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0042] As used in this application, the terms "multiple" and "each" are used, with "multiple" including two or more, and "each" referring to each of the corresponding multiples. For example, multiple positions include 7 positions, and "each" refers to each of those 7 positions.

[0043] Figure 1 This is a flowchart of a method for determining loss parameters provided in an embodiment of this application, such as... Figure 1 As shown, the method includes:

[0044] 101. Prepare a metal material sample and conduct a room temperature fatigue crack propagation test on the metal material sample until the metal material sample breaks.

[0045] The metal material sample can be any type of metal material, such as a high-temperature alloy.

[0046] In this embodiment of the application, a sample can be cut from the metal material to be evaluated to make a metal material sample. Then, a room temperature fatigue crack propagation test is performed on the metal material sample until the metal material sample fractures. The evaluation can then be based on the fatigue fracture surface of the metal material sample.

[0047] Optionally, the embodiments of this application can be applied to scenarios where the breakage parameters of flue gas turbine blades are evaluated. The metal material being evaluated is the flue gas turbine blade. Before conducting the evaluation, a metal material sample must first be prepared. Therefore, see... Figure 2 The square at the lower left corner of the blade root of the flue gas turbine is the metal material sample to be cut. The metal material sample is cut longitudinally from the blade root of the flue gas turbine and pre-cut transversely on the metal material sample so that the metal material sample can break from the crack when the room temperature fatigue crack propagation test is carried out laterally.

[0048] When cutting the specimens, CT (Compact Tension) fatigue specimens can be used. The specimens should be prepared according to JB / T8189-1999 and with reference to ASTM standard E647-81. Specimen dimensions are shown below. Figure 3 a0 represents the initial crack length, B represents the specimen thickness, W ranges from 20 to 40 mm, and the surface roughness of the machined specimen is Ra 3.2. Furthermore, if multiple specimens are to be prepared, all specimens must be of identical dimensions.

[0049] Optionally, room temperature fatigue crack propagation tests are conducted on a high-precision fatigue crack propagation testing machine. The test method refers to ASTM (American Society for Testing and Materials) standard E647-81, using CT fatigue specimens, and constant amplitude load fatigue crack propagation tests are carried out under room temperature and fatigue loading conditions until fracture.

[0050] 102. Using a scanning electron microscope and employing secondary electron imaging mode, the fatigue fracture surface of the metallic material sample is photographed to obtain the fracture surface image.

[0051] Optionally, using a scanning electron microscope and a secondary electron imaging mode, images are taken from the starting position of the fatigue fracture along the crack propagation direction until the end position of the fatigue fracture, resulting in multiple fracture images; the multiple fracture images are then stitched together to obtain a stitched fracture image.

[0052] The scanning electron microscope uses a secondary electron imaging mode, which is more sensitive to the sample surface and can reflect the morphological characteristics of the sample surface, making it convenient to assess the damage of the sample.

[0053] The starting and ending positions can be any locations selected along the width of the fatigue fracture surface. For example, both the starting and ending positions can be located in the middle region along the width of the fatigue fracture surface. Furthermore, the distance between the starting and ending positions can be arbitrary and can be determined based on the size of the fracture image used. For example, the distance between the starting and ending positions can be greater than 50% of the total distance of the fatigue fracture surface along its width, thus ensuring that the area of ​​the fracture surface used for analysis in the fracture image accounts for more than 50% of the total area of ​​the fatigue fracture surface, thereby guaranteeing the accuracy of the analysis results.

[0054] Furthermore, considering that the scanning electron microscope has a limited imaging range in a single shot and cannot capture all fracture images, multiple shots are taken starting from the beginning of the fatigue fracture and along the crack propagation direction. Each shot only captures a portion of the fatigue fracture area, resulting in one fracture image. Each fracture image contains only a portion of the fatigue fracture area. After multiple shots, multiple fracture images can be obtained. These multiple fracture images are then stitched together in the order they were captured to obtain a stitched fracture image, which can then be used for subsequent analysis.

[0055] Optionally, using a scanning electron microscope in secondary electron imaging mode, the fatigue fracture surface of the metallic material sample can be photographed from at least two fields of view to obtain at least two fracture surface images. This is because photographing the fatigue fracture surface from only one field of view yields too little information and the evaluation results are not accurate enough. Therefore, photographing the fatigue fracture surface from at least two fields of view can obtain at least two fracture surface images, enriching the information and improving the accuracy of the evaluation results.

[0056] Optionally, using a scanning electron microscope in secondary electron imaging mode, images are taken in each field of view, starting from the beginning of the fatigue fracture and proceeding along the crack propagation direction until the end of the fatigue fracture, resulting in multiple fracture images. These multiple fracture images are then stitched together to obtain the stitched fracture image corresponding to that field of view. This process is repeated for other fields of view, using the same method to obtain fracture images for those other fields of view, until at least two fracture images are obtained after all images have been captured.

[0057] 103. Determine the fracture length and corresponding stress intensity factor at multiple marked locations in the fracture image.

[0058] After obtaining the fracture surface image, the fracture length and corresponding stress intensity factor are calibrated. Fracture length calibration involves starting from the initial position and proceeding along the fracture direction to determine the fracture length at each marked position until the final position is determined. For example, the fracture length at the initial position is set to 0 mm, and the fracture length at the final position is set to 10 mm; the fracture lengths at multiple marked positions at the initial and final positions are then calibrated.

[0059] The stress intensity factor calibration is based on ASTM standard E647-81, calculating the stress intensity factor ΔK (unit: MPa·m) at fractures of different lengths. 1 / 2 Add a stress intensity factor to the fracture surface image.

[0060] 104. From the fracture surface image, determine the target location that exhibits complete intergranular fracture characteristics, and determine the stress intensity factor corresponding to the target location as the inflection point stress intensity factor.

[0061] After calibration, the target location that clearly shows the characteristics of complete intergranular fracture is determined from the calibrated fracture image. The stress intensity factor corresponding to the target location is then determined. This stress intensity factor is the inflection point of intergranular fracture of the metallic material sample. Therefore, the stress intensity factor corresponding to the target location is determined as the inflection point stress intensity factor.

[0062] Optionally, if the above step 102 involves taking pictures from at least two fields of view, steps 103 and 104 can be performed for the fracture images corresponding to each field of view, thereby determining the inflection point stress intensity factor corresponding to at least two fracture images respectively. Then, the average value of the inflection point stress intensity factor corresponding to at least two fracture images is determined as the inflection point stress intensity factor of the metallic material sample.

[0063] 105. Based on the inflection point stress intensity factor, material parameters, and initial stress intensity factor of the metallic material specimen, determine the breakage parameter of the metallic material specimen. The breakage parameter is positively correlated with the inflection point stress intensity factor, material parameters, and initial stress intensity factor.

[0064] Optionally, the loss parameters can be determined using the following formula, based on the inflection point stress intensity factor, material parameters, and initial stress intensity factor:

[0065]

[0066] Where δ is the loss parameter, ΔK T ΔK is the stress intensity factor at the inflection point. i denoted as the initial stress intensity factor, and m as a material parameter.

[0067] Optionally, in this application embodiment, the wear parameter δ is used for quantitative characterization. The wear parameter δ = 0 for new blade material that has not yet entered service, and the wear parameter δ after entering service is between 0 and 1. The larger the value, the greater the degree of wear of the blade material, that is, the shorter the remaining life.

[0068] In this embodiment, the stress intensity factor at the inflection point where the fatigue fracture surface exhibits complete intergranular fracture characteristics accurately reflects the degree of damage accumulation in the metallic material during service. Therefore, the stress intensity factor at the inflection point is used as the evaluation basis. Based on the stress intensity factor at the inflection point of the metallic material sample, the material parameters of the metallic material sample, and the initial stress intensity factor, the breakage parameter of the metallic material sample is determined. The breakage parameter is positively correlated with the stress intensity factor at the inflection point, the material parameters, and the initial stress intensity factor, thus using the breakage parameter to represent the degree of life loss of the metallic material. Compared with the methods of predicting remaining life using empirical formulas or computational simulations in related technologies, this embodiment can obtain the data required to evaluate the accumulated damage in the metallic material, without requiring a crack propagation monitoring process. The evaluation method is simple in principle, has high accuracy in evaluation results, and is convenient and easy to implement, facilitating engineering application and promotion.

[0069] It should be noted that before starting the assessment, a preliminary judgment can be made on the degree of damage to the blade material in service. The blade material should be tested for its microstructure and properties according to the flue gas turbine technical standard HG / T 3650-2012. If the reinforcing phase of the blade material has become significantly coarser and its performance has declined significantly, it indicates that the blade material has suffered significant damage. The blade material failure should be determined according to the degree of microstructure and performance decline in the technical standard, or an assessment and analysis of the breakage parameters as shown in the above embodiments should be performed. If the reinforcing phase of the blade material is not abnormal and the performance decline is not significant, then an assessment and analysis of the breakage parameters as shown in the above embodiments can be performed.

[0070] This application uses a metallic material as an example to evaluate the wear parameters of a flue gas turbine blade. First, using unused new blade material, the blades were serviced in a muffle furnace at 730°C for 500, 1000, and 1500 hours respectively, then removed and air-cooled to room temperature. Microstructural observation and room temperature fatigue crack propagation tests were then performed. Finally, the fatigue fracture surface quantitative analysis method provided in the above embodiment was used to evaluate the blade's lifespan loss.

[0071] The evaluation method specifically includes the following steps:

[0072] (1) Preliminary assessment of tissue damage after high-temperature heat exposure

[0073] The γ' strengthening phase and grain boundary carbides of the new blade material that has not yet entered service and the blade material aged at 730℃ were observed. The results showed that compared with the new blade material that has not yet entered service, the size and morphology of the γ' phase of the blade material aged at various times did not change significantly. The grain boundary carbides were stable and still distributed in a necklace-like pattern without any signs of connecting into a film.

[0074] (2) Sample preparation and testing

[0075] CT fatigue specimens were cut from new blade materials that have never been put into service and blade materials that have aged. The CT specimens were subjected to constant amplitude load fatigue crack propagation test at room temperature until they broke.

[0076] (3) Observation and calibration of fatigue fracture surface

[0077] Using a scanning electron microscope in secondary electron imaging mode, images were taken from the initiation point of the fatigue fracture along the crack propagation direction to the end of the fatigue fracture. To ensure accuracy, two fields of view were selected in the middle region along the width of the fatigue fracture for imaging from beginning to end. The morphology of the fatigue fracture in one field of view is shown below. Figure 4 As shown.

[0078] Fracture surface images were processed using image processing software to obtain the complete fatigue fracture surface image. The fracture length and corresponding stress intensity factor were then calibrated for each image. Figure 4 The left side shows the calibrated stress intensity factor, and the right side shows the calibrated fracture length.

[0079] (4) Determination of loss parameters

[0080] Identify the locations in the fracture image that clearly exhibit complete intergranular fracture characteristics, and draw lines at these locations, such as... Figure 4As shown by the black line, the stress intensity factor corresponding to this line is the intergranular fracture inflection point in that field of view. Considering both fields of view under the same fracture surface, their average value is the stress intensity factor of the intergranular fracture inflection point of the blade material. The breakage parameters of the blade material can then be obtained using formulas, as shown in Table 1.

[0081] Table 1

[0082]

[0083] The evaluation results of the damage parameters show that all materials aged at 730℃ exhibited varying degrees of lifespan reduction, with the damage parameters increasing with prolonged aging time. Extended aging time leads to more severe damage accumulation at the grain boundaries within the alloy, resulting in earlier intergranular fracture under room temperature fatigue conditions. Therefore, assessing the lifespan reduction of the alloy after exposure to high-temperature environments based on the inflection point of the intergranular fracture mode on the room temperature fatigue fracture surface is feasible.

[0084] This application also collected three in-service flue gas turbine motor blades from different refining and chemical enterprises: in-service blade 1, in-service blade 2, and in-service blade 3, and evaluated the wear parameters of these flue gas turbine motor blades. The service lives of the three in-service flue gas turbine motor blades were 0.8 years, 2 years, and 3 years, respectively. The evaluation method specifically included the following steps:

[0085] (1) Microstructure and performance tests were conducted on the in-service flue gas turbine blades 1-3 respectively. The results showed that compared with the new blades that were not in service, the γ' strengthening of the in-service blades was the same and there was no significant change, and the performance decline was not significant.

[0086] (2) CT fatigue specimens were cut from blades 1-3 of the in-service flue gas turbine. The dimensions are shown in the figure. Figure 1 A constant amplitude load fatigue crack propagation test was conducted at room temperature until the crack broke.

[0087] (3) Using the method described in the above embodiments, fracture images and scales of each service blade are obtained. The morphology of the fracture image in one field of view is as follows: Figure 5 As shown.

[0088] (4) Identify the location in the fracture image where the characteristics of complete intergranular fracture clearly appear, and draw a line at this location, such as... Figure 5 As shown by the black line, the stress intensity factor corresponding to this line is the intergranular fracture inflection point in that field of view. Considering both fields of view under the same fracture surface, their average value is the stress intensity factor of the intergranular fracture inflection point of the in-service blade, as shown in Table 2. The breakage parameters of the in-service blade can then be obtained using formulas. The service life and breakage parameters of the in-service blade are shown in Table 3.

[0089] Table 2

[0090]

[0091] Table 3

[0092]

[0093] The assessment results of the damage parameters show that the remaining service life of all flue gas turbine blades has been reduced to varying degrees after service. However, the damage parameter δ is not significantly proportional to the service duration. This is because the service environments of the flue gas turbine blades collected from various refineries differ, and therefore the damage parameter is not strictly related to the service duration. Therefore, the theoretical basis of this assessment method is that the lifespan reduction of blades in normal service depends on the cumulative damage caused by their actual service history, rather than on the accumulation of service time.

[0094] Therefore, in this embodiment of the application, the method for evaluating the deterioration parameters of metallic materials within the normal service temperature range based on the inflection point of intergranular fracture mode on the room temperature fatigue fracture surface is operable and the evaluation results are relatively accurate. It can provide a new method for evaluating the life deterioration of metallic materials that have been in long-term service at high temperatures.

[0095] Based on the above method embodiments, this application also provides an architecture diagram of a metal material processing system, which includes: a sample preparation device, a fatigue crack propagation testing machine, a scanning electron microscope, and a computer device;

[0096] Sample preparation apparatus for preparing metallic material samples;

[0097] The fatigue crack propagation tester is used to perform room temperature fatigue crack propagation tests on metallic material specimens until the metallic material specimens fracture.

[0098] A scanning electron microscope is used to photograph the fatigue fracture surface of a metallic material sample using a secondary electron imaging mode to obtain fracture images.

[0099] Computer equipment is used to determine the fracture length and corresponding stress intensity factor at multiple marked locations in a fracture image; from the fracture image, the target location exhibiting complete intergranular fracture characteristics is identified, and the stress intensity factor corresponding to the target location is determined as the inflection point stress intensity factor; based on the inflection point stress intensity factor, material parameters, and initial stress intensity factor of the metallic material specimen, the breakage parameter of the metallic material specimen is determined, and the breakage parameter is positively correlated with the inflection point stress intensity factor, material parameters, and initial stress intensity factor.

[0100] The computer device can be a mobile phone, a personal computer, or a server.

[0101] The system provided in this application can accurately reflect the degree of damage accumulation in metallic materials during service by utilizing the stress intensity factor at the inflection point where the fatigue fracture surface exhibits complete intergranular fracture characteristics. Therefore, the stress intensity factor at the inflection point is used as the evaluation basis. Based on the stress intensity factor at the inflection point of the metallic material sample, the material parameters of the metallic material sample, and the initial stress intensity factor, the breakage parameter of the metallic material sample is determined. The breakage parameter is positively correlated with the stress intensity factor at the inflection point, the material parameters, and the initial stress intensity factor, thus using the breakage parameter to represent the degree of life loss of the metallic material. Compared with the methods of predicting remaining life using empirical formulas or computational simulations in related technologies, the system provided in this application can obtain the data required to evaluate the accumulated damage in metallic materials, without requiring a crack propagation monitoring process. The evaluation method is simple in principle, has high accuracy in evaluation results, and is convenient and easy to implement, facilitating engineering application and promotion.

[0102] Optionally, a scanning electron microscope is used to take multiple fracture images from the beginning of the fatigue fracture along the crack propagation direction using a secondary electron imaging mode, up to the end of the fatigue fracture.

[0103] Computer equipment used to stitch together multiple captured fracture images to obtain a stitched fracture image.

[0104] Optionally, a scanning electron microscope is used to capture images of the fatigue fracture surface of a metallic material specimen from at least two fields of view using a secondary electron imaging mode, thereby obtaining at least two fracture surface images.

[0105] Optionally, the sample preparation device is used to longitudinally cut a metal material sample from the root of the turbine blade and to transversely cut pre-made cracks on the metal material sample.

[0106] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0107] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present application should be included within the protection scope of the present application.

Claims

1. A method for determining loss parameters, characterized in that, The method includes: Prepare a metal material sample and conduct a room temperature fatigue crack propagation test on the metal material sample until the metal material sample fractures. The fatigue fracture surface of the metal material sample was photographed using a scanning electron microscope in secondary electron imaging mode to obtain fracture surface images. Determine the fracture length and corresponding stress intensity factor at multiple marked locations in the fracture image; From the fracture image, determine the target location that exhibits complete intergranular fracture characteristics, and determine the stress intensity factor corresponding to the target location as the inflection point stress intensity factor; The breakage parameters of the metal material sample are determined based on the inflection point stress intensity factor, the material parameters of the metal material sample, and the initial stress intensity factor. The step of determining the breakage parameters of the metal material sample based on the inflection point stress intensity factor, the material parameters of the metal material sample, and the initial stress intensity factor includes: The loss parameter is determined using the following formula, based on the inflection point stress intensity factor, the material parameters, and the initial stress intensity factor: Where δ is the loss parameter, ΔK T Let ΔK be the stress intensity factor at the inflection point. i denoted as the initial stress intensity factor, and m as the material parameter.

2. The method according to claim 1, characterized in that, The process of using a scanning electron microscope in secondary electron imaging mode to photograph the fatigue fracture surface of the metallic material sample to obtain fracture images includes: Using the scanning electron microscope and the secondary electron imaging mode, images are taken from the starting position of the fatigue fracture along the crack propagation direction until the end position of the fatigue fracture, resulting in multiple fracture images. Multiple fracture images captured are stitched together to obtain a stitched fracture image.

3. The method according to claim 1, characterized in that, The process of using a scanning electron microscope in secondary electron imaging mode to photograph the fatigue fracture surface of the metallic material sample to obtain fracture images includes: Using the scanning electron microscope and the secondary electron imaging mode, the fatigue fracture surface of the metal material sample is photographed from at least two fields of view to obtain at least two fracture surface images.

4. The method according to claim 3, characterized in that, The method further includes: After determining the inflection point stress intensity factor corresponding to the at least two fracture images, the average value of the inflection point stress intensity factor corresponding to the at least two fracture images is determined as the inflection point stress intensity factor of the metallic material sample.

5. The method according to claim 1, characterized in that, The preparation of the metallic material sample includes: A metal material sample is longitudinally cut from the root of the turbine blade, and pre-made cracks are made transversely on the metal material sample.

6. A metal material processing system, characterized in that, The system includes a sample preparation device, a fatigue crack propagation testing machine, a scanning electron microscope, and computer equipment. The sample preparation device is used to prepare metallic material samples; The fatigue crack propagation testing machine is used to perform room temperature fatigue crack propagation tests on the metal material specimen until the metal material specimen fractures. The scanning electron microscope is used to photograph the fatigue fracture surface of the metal material sample using a secondary electron imaging mode to obtain a fracture surface image. The computer device is used to determine the fracture length and corresponding stress intensity factor at multiple marked locations in the fracture image; From the fracture image, the target location exhibiting complete intergranular fracture characteristics is determined, and the stress intensity factor corresponding to the target location is determined as the inflection point stress intensity factor; based on the inflection point stress intensity factor of the metal material sample, the material parameters of the metal material sample, and the initial stress intensity factor, the breakage parameters of the metal material sample are determined. The computer device is configured to determine the breakage parameter using the following formula, based on the inflection point stress intensity factor, the material parameter, and the initial stress intensity factor: Where δ is the loss parameter, ΔK T Let ΔK be the stress intensity factor at the inflection point. i denoted as the initial stress intensity factor, and m as the material parameter.

7. The system according to claim 6, characterized in that, The scanning electron microscope is used to take pictures from the starting position of the fatigue fracture along the crack propagation direction using the secondary electron imaging mode, until the end position of the fatigue fracture, to obtain multiple fracture images. The computer device is used to stitch together multiple captured fracture images to obtain a stitched fracture image.

8. The system according to claim 6, characterized in that, The scanning electron microscope is used to take pictures of the fatigue fracture surface of the metal material sample from at least two fields of view using the secondary electron imaging mode, so as to obtain at least two fracture surface images.

9. The system according to claim 6, characterized in that, The sample preparation device is used to longitudinally cut a metal material sample from the root of the turbine blade and to transversely cut a pre-made crack on the metal material sample.

Images