A method of testing the yield point of a high temperature material

Abstract

The application discloses a high-temperature material yield point testing method and relates to the technical field of high-temperature material testing. The technical problem that the stress parameter of the high-temperature material changes at different temperature states and the stress test result is not accurate, and the abnormal high-temperature material is directly removed without analyzing whether the abnormal high-temperature material affects normal use, thereby reducing quantitative loss is solved. According to the established two-dimensional coordinate change curve, the stress parameter of the high-temperature material at different residence temperature states is confirmed, and according to the confirmed stress parameter, it is analyzed and determined whether the corresponding high-temperature material stress test is normal. If abnormal, limit testing is performed to analyze whether the abnormal high-temperature material affects normal use, the practicability of the system is improved, the high-temperature material is not used due to stress abnormality, and production loss is reduced to a certain extent.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature material testing technology, specifically a method for testing the yield point of high-temperature materials. Background Technology

[0002] Materials that can withstand certain stress and have the ability to resist oxidation and hot corrosion at temperatures above 550℃ are suitable for manufacturing important load-bearing structural components for aero engines and rocket engines. High-temperature materials include high-temperature alloys, dispersion-strengthened alloys, refractory alloys, metal fiber-reinforced high-temperature composite materials, and ceramic materials.

[0003] Patent publication number CN111855434A discloses a method for testing the yield point of high-temperature materials. It includes the following steps: Step 1, loading the sample: loading the sample onto the testing device; Step 2, applying stress: applying a certain preload to the sample; Step 3, simulating the service environment of the test material; Step 4, testing the axial deformation of the sample under applied stress; Step 5, establishing a two-dimensional coordinate graph of temperature and axial deformation, marking the coordinates of the highest temperature point and the axial deformation during heating and cooling, fitting two corresponding relationship curves, and determining the starting point of separation between the two curves, which is the temperature at which the material sample yields under applied stress. The advantages of this invention are: reducing the time and cost of the highest temperature environment during the test process, obtaining accurate and reliable test results, and ensuring the safety of high-temperature materials in use.

[0004] In the process of yield point testing of high-temperature materials, stress load is generally applied to the high-temperature material, and the stress parameters of the yield are recorded to determine whether the high-temperature material passes the test. However, this method does not take into account that the stress parameters of the high-temperature material will change under different temperature conditions, which can easily lead to inaccurate stress test results. Furthermore, abnormal high-temperature materials are directly rejected without analyzing whether the abnormal high-temperature materials will affect normal use, thus failing to reduce quantitative losses. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art; to this end, the present invention proposes a method for testing the yield point of high-temperature materials, which is used to solve the technical problem that the stress parameters of high-temperature materials will change under different temperature conditions, which easily leads to inaccurate stress test results, and abnormal high-temperature materials are directly rejected without analyzing whether the abnormal high-temperature materials will affect normal use, thereby reducing quantitative loss.

[0006] To achieve the above objectives, an embodiment of the first aspect of the present invention provides a method for testing the yield point of high-temperature materials, comprising the following steps:

[0007] S1. Acquire the surface image of the high-temperature material to be tested, perform modeling processing based on the acquired surface image to obtain the volume parameters of this high-temperature material, and label the acquired surface image as the image to be compared.

[0008] S2. Place the high-temperature material to be tested in a sealed environment, gradually adjust the temperature parameters of this sealed environment, determine the temperature change period during the adjustment process, confirm the volume change of the high-temperature material, and establish a temperature-volume change curve. The specific method is as follows:

[0009] S21. The temperature parameters of the closed environment are gradually changed, with a change period of T. During the temperature change, there are corresponding dwell temperatures. The dwell time between each set of dwell temperatures is the change period T.

[0010] S22. Acquire surface images of high-temperature materials at different residence temperatures in a sealed environment. Analyze and compare the acquired surface images with the comparison images identified in step S1 to determine abnormal areas. Based on the determined abnormal areas, obtain the expansion volume parameters of the high-temperature material after expansion. The specific method is as follows:

[0011] S221. Using the correct image acquisition method, acquire surface images of high-temperature materials, compare the acquired surface images with the images to be compared, and identify abnormal areas.

[0012] S222. Determine the first region image of the abnormal area, and then acquire the image of the opposite side of the abnormal area of ​​the high-temperature material. The acquired image is designated as the second region image. Determine whether the abnormal area is attached to the edge line of the high-temperature material. If it is attached, acquire the image of the attached area between the first region image and the second region image, and mark it as the third region image. Model the abnormal area based on the first region image, the second region image, and the third region image to obtain the volume parameters of the abnormal area. If they are not attached, model the abnormal area directly through the first region image and the second region image. Obtain the volume parameters of the abnormal area based on the width value of the internal parameters of the high-temperature material.

[0013] S223. Based on the determined volume parameters of the abnormal region, confirm the expansion volume parameters of the high-temperature material after expansion;

[0014] S23. Confirm the expansion volume parameters under different residence temperature conditions in sequence, and establish a two-dimensional coordinate change curve between different residence temperatures and expansion volume parameters;

[0015] S3. Based on the established two-dimensional coordinate variation curve, confirm the stress parameters of this high-temperature material under different holding temperatures. Then, based on the confirmed stress parameters, analyze and determine whether the stress test of the corresponding high-temperature material is normal. The specific method is as follows:

[0016] S31. Label different residence temperatures as TL. i Where i represents different residence temperatures, i = 1, 2, ..., n, and the expansion volume at different residence temperatures is denoted as PZ. k , where k represents different expansion volumes, and k = 1, 2, ..., m, the volume parameter of this high-temperature material is denoted as TJ;

[0017] S32, Adopt The coefficient of thermal expansion PX of this high-temperature material at the corresponding residence temperature was obtained. i , where YS is the external ambient temperature parameter;

[0018] S33, then use YL i =PX i ×(TL i -YS)×elastic modulus, to obtain the stress parameter YL of this high-temperature material at the corresponding residence temperature. i The elastic modulus is a preset value;

[0019] S34. Obtain the preset stress range for the corresponding residence temperature state, where the preset stress range is a standard value. When the obtained stress parameters YL for different residence temperature states... i When the value is within the preset stress range corresponding to the holding temperature state, it means that the stress test of the corresponding high-temperature material is normal; otherwise, it means that the stress test of the corresponding high-temperature material is abnormal.

[0020] S4. Confirm the high-temperature material with abnormal stress, extract the two-dimensional coordinate change curve of the corresponding high-temperature material, and then obtain the volume change trend of the corresponding high-temperature material based on the two-dimensional coordinate change curve. Obtain the volume change trend range of this high-temperature material, and conduct limit tests on the high-temperature material with abnormal stress based on this volume change trend range to determine whether the corresponding high-temperature material affects normal use. The specific method is as follows:

[0021] S41. Obtain the expansion volume PZ at different residence temperatures. k And simultaneously obtain different residence temperatures TL i ,use The volume trend parameter QS at different residence temperatures was obtained. i Where j∈k, t∈i, from several sets of volume trend parameters QS i Extract the maximum and minimum values ​​within the range, and determine the volume change trend range based on the extracted maximum and minimum values;

[0022] S42. Compare the determined volume change trend range with the preset volume parameter range. The preset volume parameter range is a preset range, and its specific value is determined by the operator based on experience. When the volume change trend range ∈ the preset volume parameter range, a limit test signal is generated; otherwise, an abnormal signal is generated and transmitted to the external display terminal for display.

[0023] S43. Based on the limit test signal, perform a limit test on the high-temperature material with abnormal stress. Apply a specified stress value to the high-temperature material, where the specified stress value is a preset value, and obtain the yield strength of the high-temperature material. Mark the obtained yield strength as QF. p , where p represents high-temperature materials with different stress anomalies;

[0024] S44. The obtained yield strength QF p Compare with the preset parameter Y1, when QF p When ≥Y1, it indicates that the high-temperature material limit test for this stress anomaly is normal, and a normal signal is generated and transmitted to the external display terminal. When QF p When the value is less than Y1, it indicates an abnormality in the high-temperature material limit test due to this stress anomaly, and an abnormality signal is generated and transmitted to the external display terminal.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: the volume parameters of the high-temperature material are obtained and confirmed in advance based on the surface image of the high-temperature material, and then the abnormal area generated on the surface of the high-temperature material is determined by the temperature change. The corresponding expansion volume is then confirmed through the abnormal area. Subsequently, stress test is performed on the high-temperature material based on the expansion volume, and the stress parameters under different temperature conditions are then confirmed. The method of confirming the expansion volume through the abnormal area makes the determined volume parameters more accurate and the acquisition method is faster, thus improving the accuracy of stress test to a certain extent.

[0026] Subsequently, based on the established two-dimensional coordinate change curve, the stress parameters of this high-temperature material under different holding temperatures are confirmed. Then, based on the confirmed stress parameters, it is analyzed and determined whether the stress test of the corresponding high-temperature material is normal. If abnormal, an extreme test is conducted to analyze whether the abnormal high-temperature material will affect normal use, improve the practicality of this system, and prevent the high-temperature material from being discontinued due to stress abnormalities, thereby reducing production losses to a certain extent. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1

[0030] Please see Figure 1 This application provides a method for testing the yield point of high-temperature materials, comprising the following steps:

[0031] S1. Acquire surface images of the high-temperature material to be tested, perform modeling processing based on the acquired surface images to obtain the volume parameters of this high-temperature material, and label the acquired surface images as comparison images. The specific method for obtaining the volume parameters of this high-temperature material is as follows:

[0032] S11. A set of reference planes is established in advance using a set of surface images of high-temperature materials, and the reference body is obtained by extending based on these reference planes;

[0033] S12. Subsequently, the other surface images of the high-temperature material are filled into the corresponding surfaces of the reference body to obtain the model body belonging to this high-temperature material.

[0034] S13. Obtain the volume parameters of this model directly through the internal volume acquisition command;

[0035] S2. Place the high-temperature material to be tested in a sealed environment, gradually adjust the temperature parameters of this sealed environment, determine the temperature change period during the adjustment process, confirm the volume change of the high-temperature material, and establish a temperature-volume change curve. The specific method for confirmation is as follows:

[0036] S21. The temperature parameters of the closed environment are gradually changed, with a change cycle of T, where T is a preset value. The specific value is determined by the operator based on experience, and T is generally set to 5 minutes. During the temperature change process, there are corresponding dwell temperatures, with an interval of 50°C between each group of dwell temperatures. The reason for carrying out this in a closed environment is to avoid the influence of the external ambient temperature. The dwell time between each group of dwell temperatures is the change cycle T.

[0037] S22. Acquire surface images of high-temperature materials at different residence temperatures in a sealed environment. Analyze and compare the acquired surface images with the comparison images confirmed in step S1 to identify abnormal areas. Based on the identified abnormal areas, obtain the expansion volume parameters of the high-temperature material after expansion. The specific method for obtaining the expansion volume parameters is as follows:

[0038] S221. Use the correct image acquisition posture. Specifically, when acquiring images, confirm the image acquisition posture according to the preset image placement posture to avoid misjudgment caused by the difference in the overall comparison posture between the acquired image and the image to be compared. Acquire the surface image of the high-temperature material, compare the acquired surface image with the image to be compared, and determine the abnormal area.

[0039] S222. Determine the first region image of the abnormal region, and then acquire the opposite image of the abnormal region of the high-temperature material. The acquired image is designated as the second region image. Determine whether the abnormal region is attached to the edge line of the high-temperature material. If it is attached, acquire the image of the attachment area between the first region image and the second region image, and mark it as the third region image. Model the abnormal region based on the first region image, the second region image, and the third region image to obtain the volume parameters of the abnormal region. If they are not attached, model the abnormal region directly through the first region image and the second region image. Obtain the volume parameters of the abnormal region based on the width value of the internal parameters of the high-temperature material. Specifically, the model body of the original high-temperature material has been established, so the internal parameters can be directly obtained. By changing the corresponding region and combining it with the original model body, the volume parameters of the corresponding abnormal region can be obtained. The abnormal region is the expansion region. During the process of confirming the abnormal region, the image on its surface may expand. The region image generated by the expansion is different from the actual comparison image. Therefore, the corresponding region image generated is directly acquired as the image of the abnormal region.

[0040] S223. Based on the determined volume parameters of the abnormal region, confirm the expansion volume parameters of the high-temperature material after expansion. Specifically, obtain the corresponding volume difference value by comparing the volume parameters of the abnormal region with the original volume parameters of the original region, and then confirm the expansion volume parameters based on the volume difference value and the original volume parameters of the high-temperature material.

[0041] S23. Confirm the expansion volume parameters under different residence temperature conditions in sequence, and establish a two-dimensional coordinate change curve between different residence temperatures and expansion volume parameters;

[0042] S3. Based on the established two-dimensional coordinate change curve, confirm the stress parameters of this high-temperature material under different holding temperatures. Then, based on the confirmed stress parameters, analyze and determine whether the stress test of the corresponding high-temperature material is normal. The specific method of analysis and determination is as follows:

[0043] S31. Label different residence temperatures as TL. i Where i represents different residence temperatures, i = 1, 2, ..., n, and the expansion volume at different residence temperatures is denoted as PZ. k, where k represents different expansion volumes, and k = 1, 2, ..., m, the volume parameter of this high-temperature material is denoted as TJ;

[0044] S32, Adopt The coefficient of thermal expansion PX of this high-temperature material at the corresponding residence temperature was obtained. i Where YS is the external ambient temperature parameter, and specifically, the formula for calculating the coefficient of thermal expansion of high-temperature materials is: Volume after change - Volume before change / Volume before change × Temperature difference.

[0045] S33, then use YL i =PX i ×(TL i -YS)×elastic modulus, to obtain the stress parameter YL of this high-temperature material at the corresponding residence temperature. i The elastic modulus is given by the operator based on the specific high-temperature material, and the elastic modulus is a preset value. Specifically, the elastic modulus parameters given are different for different high-temperature materials. Specifically, the stress calculation formula for high-temperature materials is: stress parameter = expansion coefficient × temperature difference × elastic modulus.

[0046] S34. Obtain the preset stress range for the corresponding dwell temperature state, where the preset stress range is a standard value, and the interval parameters within the preset stress range are determined by the operator based on experience. When the obtained stress parameters YL for different dwell temperature states... i When the stress value is within the preset stress range corresponding to the holding temperature state, it means that the stress test of the corresponding high-temperature material is normal; otherwise, it means that the stress test of the corresponding high-temperature material is abnormal. Specifically, during the testing process of high-temperature materials, if the stress test of the high-temperature material is qualified under a certain set of holding temperature states, the stress under other holding temperature states will generally also be qualified. Conversely, if the stress test is abnormal under a certain set of holding temperature states, then the stress under other holding temperature states will generally also be in an abnormal state.

[0047] S4. Confirm the high-temperature material with abnormal stress, extract the two-dimensional coordinate change curve of the corresponding high-temperature material, and then obtain the volume change trend of the corresponding high-temperature material based on the two-dimensional coordinate change curve. Obtain the volume change trend range of this high-temperature material, and perform limit tests on the high-temperature material with abnormal stress based on this volume change trend range to determine whether the corresponding high-temperature material affects normal use. The specific method of determination is as follows:

[0048] S41. Obtain the expansion volume PZ at different residence temperatures. k And simultaneously obtain different residence temperatures TL i ,use The volume trend parameter QS at different residence temperatures was obtained. iWhere j∈k, t∈i, from several sets of volume trend parameters QS i Extract the maximum and minimum values ​​within the range, and determine the volume change trend range based on the extracted maximum and minimum values;

[0049] S42. Compare the determined volume change trend range with the preset volume parameter range. The preset volume parameter range is a preset range, and its specific value is determined by the operator based on experience. When the volume change trend range is ∈ the preset volume parameter range, a limit test signal is generated. Otherwise, an abnormal signal is generated and transmitted to the external display terminal for display by the external operator.

[0050] S43. Based on the limit test signal, perform a limit test on the high-temperature material with abnormal stress. Apply a specified stress value to the high-temperature material, where the specified stress value is a preset value, and its specific value is determined by the operator based on experience. Obtain the yield strength of the high-temperature material and mark the obtained yield strength as QF. p Where p represents high-temperature materials with different stress anomalies, specifically, the yield strength obtained is related to the yield degree of the corresponding high-temperature material, and can be obtained through the yield degree and the corresponding conversion parameters. The yield degree can be understood as the deformation parameter generated by the corresponding high-temperature material during the test.

[0051] S44. The obtained yield strength QF p Compare with the preset parameter Y1, when QF p When ≥Y1, it means that the extreme test of the high-temperature material with abnormal stress is normal, and a normal signal is generated and transmitted to the external display terminal. This means that although the stress test of the high-temperature material is abnormal, it can be used normally in actual use. Conversely, it means that the extreme test of the high-temperature material with abnormal stress is abnormal, and an abnormal signal is generated and transmitted to the external display terminal. This means that the high-temperature material with abnormal stress cannot be used normally.

[0052] Example 2

[0053] In this embodiment, compared to Embodiment 1, the change period T is generally set to 10 minutes, and the interval between each group of dwell temperatures is 100°C.

[0054] The data in the above formula are all calculated by removing the dimensions and taking the numerical values. The formula is the closest to the real situation obtained by software simulation of a large amount of collected data. The preset parameters and preset thresholds in the formula are set by those skilled in the art according to the actual situation or obtained through simulation of a large amount of data.

[0055] The working principle of this invention is as follows: Based on the surface image of the high-temperature material, the volume parameters of the high-temperature material are obtained and confirmed in advance. Then, by changing the temperature, the abnormal areas generated on the surface of the high-temperature material are determined, and the corresponding expansion volume is confirmed through the abnormal areas. Subsequently, stress tests are performed on the high-temperature material based on the expansion volume, and the stress parameters under different temperature conditions are confirmed. By using the method of confirming the expansion volume through abnormal areas, the determined volume parameters are more accurate and the acquisition method is faster, which improves the accuracy of stress testing to a certain extent.

[0056] Subsequently, based on the established two-dimensional coordinate change curve, the stress parameters of this high-temperature material under different holding temperatures are confirmed. Then, based on the confirmed stress parameters, it is analyzed and determined whether the stress test of the corresponding high-temperature material is normal. If abnormal, an extreme test is conducted to analyze whether the abnormal high-temperature material will affect normal use, improve the practicality of this system, and prevent the high-temperature material from being discontinued due to stress abnormalities, thereby reducing production losses to a certain extent.

[0057] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A method for testing the yield point of high-temperature materials, characterized in that, Includes the following steps: S1. Acquire the surface image of the high-temperature material to be tested, perform modeling processing based on the acquired surface image to obtain the volume parameters of this high-temperature material, and label the acquired surface image as the image to be compared. S2. Place the high-temperature material to be tested in a sealed environment, gradually adjust the temperature parameters of this sealed environment, determine the temperature change period during the adjustment process, confirm the volume change of the high-temperature material, and establish a temperature-volume change curve. The specific method is as follows: S21. The temperature parameters of the closed environment are gradually changed, with a change period of T. During the temperature change, there are corresponding dwell temperatures. The dwell time between each set of dwell temperatures is the change period T. S22. Acquire surface images of high-temperature materials at different residence temperatures in a sealed environment. Analyze and compare the acquired surface images with the comparison images identified in step S1 to determine abnormal areas. Based on the determined abnormal areas, obtain the expansion volume parameters of the high-temperature material after expansion. The specific method is as follows: S221. Using the correct image acquisition method, acquire surface images of high-temperature materials, compare the acquired surface images with the images to be compared, and identify abnormal areas. S222. Determine the first region image of the abnormal area, and then acquire the image of the opposite side of the abnormal area of ​​the high-temperature material. The acquired image is designated as the second region image. Determine whether the abnormal area is attached to the edge line of the high-temperature material. If it is attached, acquire the image of the attached area between the first region image and the second region image, and mark it as the third region image. Model the abnormal area based on the first region image, the second region image, and the third region image to obtain the volume parameters of the abnormal area. If they are not attached, model the abnormal area directly through the first region image and the second region image. Obtain the volume parameters of the abnormal area based on the width value of the internal parameters of the high-temperature material. S223. Based on the determined volume parameters of the abnormal region, confirm the expansion volume parameters of the high-temperature material after expansion; S23. Confirm the expansion volume parameters under different residence temperature conditions in sequence, and establish a two-dimensional coordinate change curve between different residence temperatures and expansion volume parameters; S3. Based on the established two-dimensional coordinate change curve, confirm the stress parameters of this high-temperature material under different holding temperature conditions, and then analyze and determine whether the stress test of the corresponding high-temperature material is normal based on the confirmed stress parameters. S4. Confirm the high-temperature material with abnormal stress, extract the two-dimensional coordinate change curve of the corresponding high-temperature material, and then obtain the volume change trend of the corresponding high-temperature material based on the two-dimensional coordinate change curve. Obtain the volume change trend range of this high-temperature material, and conduct limit tests on the high-temperature material with abnormal stress based on this volume change trend range to determine whether the corresponding high-temperature material affects normal use. The specific method is as follows: S41. Obtain the expansion volume PZ at different residence temperatures. k And simultaneously obtain different residence temperatures TL i ,use The volume trend parameter QS at different residence temperatures was obtained. i Where j∈k, t∈i, from several sets of volume trend parameters QS i Extract the maximum and minimum values ​​within the range, and determine the volume change trend range based on the extracted maximum and minimum values; S42. Compare the determined volume change trend range with the preset volume parameter range. The preset volume parameter range is a preset range, and its specific value is determined by the operator based on experience. When the volume change trend range ∈ the preset volume parameter range, a limit test signal is generated; otherwise, an abnormal signal is generated and transmitted to the external display terminal for display. S43. Based on the limit test signal, perform a limit test on the high-temperature material with abnormal stress. Apply a specified stress value to the high-temperature material, where the specified stress value is a preset value, and obtain the yield strength of the high-temperature material. Mark the obtained yield strength as QF. p , where p represents high-temperature materials with different stress anomalies; S44. The obtained yield strength QF p Compare with the preset parameter Y1, when QF p When ≥Y1, it indicates that the high-temperature material limit test for this stress anomaly is normal, and a normal signal is generated and transmitted to the external display terminal.

2. The method for testing the yield point of high-temperature materials according to claim 1, characterized in that, In step S3, the specific method for determining whether the high-temperature material stress test is normal is as follows: S31. Label different residence temperatures as TL. i Where i represents different residence temperatures, i = 1, 2, ..., n, and the expansion volume at different residence temperatures is denoted as PZ. k , where k represents different expansion volumes, and k = 1, 2, ..., m, the volume parameter of this high-temperature material is denoted as TJ; S32, Adopt The coefficient of thermal expansion PX of this high-temperature material at the corresponding residence temperature was obtained. i , where YS is the external ambient temperature parameter; S33, then use YL i =PX i ×(TL i -YS) × elastic modulus, yielding the stress parameter YL of this high-temperature material at the corresponding residence temperature. i The elastic modulus is a preset value; S34. Obtain the preset stress range for the corresponding residence temperature state, where the preset stress range is a standard value. When the obtained stress parameters YL for different residence temperature states... i When the value is within the preset stress range corresponding to the holding temperature state, it indicates that the stress test of the corresponding high-temperature material is normal; otherwise, it indicates that the stress test of the corresponding high-temperature material is abnormal.

3. The method for testing the yield point of high-temperature materials according to claim 1, characterized in that, In step S44, when QF p When the value is less than Y1, it indicates an abnormality in the high-temperature material limit test due to this stress anomaly, and an abnormality signal is generated and transmitted to the external display terminal.

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