Tiny equivalent ultrasonic flaw detection method for rotor forging
Through the method of fitting dense defect equivalent and defect size, combined with cold processing material collection and macro-structure detection, the accuracy of micro-intensive defect detection and non-metallic inclusion interference of ultra-large and super-thick rotor forgings is solved, and the high level of ultra-large rotor forgings is achieved. Reduced accuracy detection and misjudgment rate.
Patent Information
- Application Number
- CN202411372402.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2024-12-13
AI Technical Summary
The prior art detects tiny dense defects of ultra-large and thick rotor forgings, and is unable to effectively deal with the interference of irregular surfaces of non-metallic inclusions on ultrasonic waves, resulting in misjudgment and scrapping of forgings.
Using the method of fitting the dense defect equivalent and defect size, the dense defect equivalent of the defect is obtained through ultrasonic detection, and combined with the defect information of the forgings of alternative data sources, cold processing material collection and macro-structure detection are used to establish the correspondence between the defect size and the dense defect equivalent. Relationship, improve detection accuracy and scope of application.
Effective detection of ultra-large and super-thick rotor forgings with diameters exceeding 2800mm is achieved, the detection accuracy of dense defects less than 0.1mm is improved, the resolution of interference with non-metallic inclusions is enhanced, and the misjudgment rate is reduced.
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Figure CN119125327A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of composite material forming, and in particular to a method for detecting a rotor forging with a micro-equivalent ultrasonic flaw detection. Background Art
[0002] Rotor forgings have harsh operating conditions and complex stress states. The ultrasonic flaw detection acceptance is extremely strict, and some standards even have no lower acceptance limit. It is necessary to record all displays and conduct forging availability assessment. Ultrasonic flaw detection mainly achieves the purpose of detection through grain boundary reflection echo. The ultrasonic flaw detection display signal, especially the micro-equivalent display signal, is affected by multiple factors: the degree of grain refinement or homogenization of the forging, the organizational state, the distribution of inclusions, the surface processing state, etc., all of which interfere with whether the micro-equivalent display signal reflects the true state of the forging.
[0003] The manufacturing process of rotor forgings, especially those for 600MW-1000MW steam turbine units, is complicated. They go through smelting-forging-preparatory heat treatment-rough machining-quenching and tempering heat treatment-various testing stages in the manufacturing plant, with high manufacturing costs and long manufacturing cycles. During the ultrasonic testing process after quenching and tempering, once a tiny equivalent ultrasonic flaw detection display signal appears, the safety and reliability of the forgings cannot be assessed. If a misjudgment occurs, the forgings will be scrapped, which will lead to a waste of initial time and economic costs.
[0004] On the one hand, the existing technology has developed an ultrasonic scattering method to detect tiny defects (less than 0.1mm) in metal materials. There is also a method that uses the principle of ultrasonic interference to study the interference law between the incident wave and the scattered wave of tiny defects, and uses the amplitude of the interference wave train at the tail of the bottom wave as the imaging parameter to obtain a grayscale image of tiny defects. However, these technologies are limited by their own detection principles and are only limited to the detection of thin-walled parts with an ultrasonic propagation path of ≤80mm. They cannot be applied to ultra-large and ultra-thick rotor forgings with a diameter of more than 2800mm. On the other hand, this method has worse detection accuracy and precision for dense tiny defects than for single independent defects due to the mutual interference of reflected waves between dense defects or irregular echoes of defects. Dense defects are an important reason for misjudgment and scrapping of forgings.
[0005] On the other hand, the correspondence between defect size and flaw detection equivalent established by the prior art uses an artificially manufactured circular flat-bottom hole to characterize the size of the actual defect, adjusts the sound path during the measurement process to be consistent, and adjusts the probe angle to make the sound beam perpendicular to the surface of the sample to obtain a proportional relationship between the reflected wave amplitude and the defect area. However, the detection results are less than ideal, the scattering resolution and accuracy are low, and it is impossible to simulate the degree of interference of the irregular surface of the actual non-metallic inclusions on the scattered wave. Therefore, it is easily affected by the irregular surface of the non-metallic inclusions and has a low resolution. Summary of the invention
[0006] In view of the above analysis and in response to the deficiencies in the prior art, the present invention aims to provide a method for detecting rotor forgings using micro-equivalent ultrasonic flaw detection to solve at least one of the problems of low accuracy in detecting tiny dense defects, low resolution of interference from irregular surfaces of non-metallic inclusions, and difficulty in detecting ultra-large and ultra-thick rotor forgings.
[0007] The purpose of the present invention is mainly achieved through the following technical solutions:
[0008] The present invention discloses a rotor forging micro-equivalent ultrasonic flaw detection method, comprising:
[0009] S1: Obtain the dense defect equivalent of the defects of the rotor forging to be tested based on ultrasonic testing;
[0010] S2: obtaining the defect position size of the rotor forging to be tested based on the corresponding relationship between the defect size of the rotor forging to be tested and the dense defect equivalent;
[0011] S3: Determine the defect level of the rotor forging to be tested based on the number of potential defect locations and defect location sizes of the rotor forging to be tested.
[0012] Preferably, the dense defect equivalent is a quantity determined by the AVG method.
[0013] Preferably, the corresponding relationship between the defect size y and the dense defect equivalent x of the rotor forging to be tested in S2 satisfies: y=A1×exp(-x / t1)+y0, wherein: y0, A1, t1 are constants.
[0014] Preferably, y0=-7.115±0.35.
[0015] Preferably, A1 = 11.49422 ± 0.12.
[0016] Preferably, t1 = -0.65584±0.02.
[0017] Preferably, obtaining the corresponding relationship between the defect size y and the dense defect equivalent x of the rotor forging to be tested in S2 includes:
[0018] S201: Select a rotor forging having the same volume, shape and material as the rotor forging to be tested as a candidate data source rotor forging;
[0019] S202: obtaining defect position information and defect equivalent information of the candidate data source rotor forging based on ultrasonic testing, selecting the candidate data source rotor forging with dense defects as the data source rotor forging, and recording the dense defect position information and dense defect equivalent of the data source rotor forging;
[0020] S203: Based on the dense defect position information of the rotor forging of the data source, processing is performed to the depth plane where the defect is located, and dense defect size information corresponding to the dense defect position information is collected;
[0021] S204: Based on the dense defect size information corresponding to the dense defect equivalent, obtain the corresponding relationship between the defect size y and the dense defect equivalent x of the rotor forging to be tested.
[0022] Preferably, the method for collecting dense defect size information corresponding to dense defect position information in S203 includes:
[0023] S2031, performing cold working and material extraction at the dense defect depth position based on the dense defect position information of the rotor forging of the data source;
[0024] S2032. Perform macroscopic structural inspection and inclusion analysis on the depth position of dense defects, and count the number and average size of inclusions in each layer.
[0025] Preferably, the cold working material removal in S2031 includes grinding the data source rotor forging layer by layer.
[0026] Preferably, the macroscopic structure detection and inclusion analysis performed in S2032 include scanning electron microscope analysis and optical microscope analysis.
[0027] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:
[0028] (1) The present invention adopts the dense defect equivalent to fit the defect size of the rotor forging to be tested. Since the dense defect equivalent includes the material attenuation coefficient, defect depth, dB difference between the bottom wave and the defect echo, and the sound path, it is a comprehensive measurement parameter. On the one hand, unlike the ultrasonic scattering and ultrasonic interference methods in the prior art, the present invention is not limited by ultrasonic scattering and interference depth. The method is not limited to the detection of thin-walled parts with an ultrasonic propagation path of ≤80mm, and is also applicable to ultra-large and ultra-thick rotor forgings with a diameter of more than 2800mm. On the other hand, compared with the corresponding relationship between defect size and flaw detection equivalent established in the prior art, an artificially manufactured circular flat-bottom hole is used to characterize the actual defect size, and the sound path of the measurement process is adjusted to be consistent. The probe angle is adjusted to make the sound beam perpendicular to the surface of the sample to obtain a proportional relationship between the reflected wave amplitude and the defect area. The present invention simplifies the condition restrictions, expands the scope of application, and considers more factors and variables at the same time, thereby improving the detection accuracy of dense defects less than 0.1mm, especially less than 0.05mm.
[0029] (2) The defect size fitting relationship of the present invention with the dense equivalent as the variable, in the chromium-molybdenum alloy system for rotor forgings, the constants of the corresponding relationship between the defect size y and the dense defect equivalent x obtained by fitting the data source rotor forgings of different volumes, shapes and materials fluctuate reasonably within a small range, and the confidence level R 2 ≥0.99565, with good accuracy and reliability, and good applicability to chromium-molybdenum alloy systems for rotor forgings of different sizes and models.
[0030] (3) The present invention grinds and polishes the data source rotor forging layer by layer through cold processing, which can retain the real defect information of the original rotor forging as much as possible, and helps to improve the accuracy of the fitting relationship. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.
[0032] Figure 1a It is a schematic diagram of a dense defect in ultrasonic flaw detection according to the present invention.
[0033] Figure 1b It is a schematic diagram of a single defect in ultrasonic flaw detection according to the present invention.
[0034] Figure 2 This is the corresponding relationship between the defect size and the dense defect equivalent fitted in Example 1 of the present invention.
[0035] Figure 3 This is the corresponding relationship between the defect size and the dense defect equivalent fitted in Example 2 of the present invention.
[0036] Reference numerals:
[0037] Single wave peak 001; reflection wave from the forging and air interface 002; dense defect detection wave 003. DETAILED DESCRIPTION
[0038] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0039] The present invention discloses a method for detecting a rotor forging by using a micro-equivalent ultrasonic flaw detection method, comprising:
[0040] S1: Obtain the dense defect equivalent of the defects of the rotor forging to be tested based on ultrasonic testing;
[0041] S2: obtaining the defect position size of the rotor forging to be tested based on the corresponding relationship between the defect size of the rotor forging to be tested and the dense defect equivalent;
[0042] S3: Determine the defect level of the rotor forging to be tested based on the number of potential defect locations and defect location sizes of the rotor forging to be tested.
[0043] It should be noted that the dense defect equivalent Φ in S1 fSpecifically, the dense defect equivalent of the potential defects of the rotor forging to be tested obtained based on ultrasonic testing in S1 satisfies:
[0044]
[0045] in:
[0046] α——Material attenuation coefficient, unit: dB / mm;
[0047] x f ——defect depth, in mm;
[0048] Φ f ——equivalent diameter of defect, in mm;
[0049] B / B f ——dB difference between the bottom wave and the defect echo, in dB;
[0050] S——sound path, in mm, can be measured by ultrasonic testing equipment;
[0051] λ is the wavelength of sound waves in the medium.
[0052] Specifically, Figure 1a As shown, the dense defect equivalent in step S1 and step S2 refers to the dense defect detection wave 003 with multiple peaks, corresponding to the impurity defects with complex shapes; Figure 1b The single defect with a single peak 001 shown in the figure and the dense defect equivalent with multiple peaks can be distinguished from the ultrasonic detection image. Figure 1a-1b Figure 002 is the reflected wave from the interface between the forging and the air.
[0053] Specifically, the present invention refers to the definition of dense defects in the large casting and forging industry standard JB / T5000.15-2007 "General Technical Conditions for Heavy Machinery Part 15: Non-destructive Testing of Forged Steel Parts": There are five or more defect reflection signals at the same time within the range of 50mm sound path of the fluorescent screen scanning line; or there are five or more defect reflection signals within the same depth on the 50mm×50mm detection surface.
[0054] It should be noted that ultrasonic testing based on the existing technology can obtain all defect information (defect equivalent, defect depth, defect coordinate position information, etc.) of the rotor forging to be tested, and based on the above-mentioned dense defect judgment method, dense defects can be screened out from the defects and their dense defect equivalents can be recorded.
[0055] It can be understood that the defect depth, defect coordinate position information, etc. obtained simultaneously by ultrasonic testing can be used as defect identity information to mark the above-mentioned dense defects, so as to facilitate subsequent data processing.
[0056] Compared with the prior art, the dense defect equivalent is used to fit the defect size of the rotor forging to be tested. Since the dense defect equivalent includes the material attenuation coefficient, defect depth, dB difference between the bottom wave and the defect echo, and the sound path, it is a comprehensive measurement parameter: on the one hand, different from the ultrasonic scattering and ultrasonic interference methods in the prior art, the present invention is not limited by ultrasonic scattering and interference depth. The method is not limited to the detection of thin-walled parts with an ultrasonic propagation path of ≤80mm, and is also applicable to ultra-large and ultra-thick rotor forgings with a diameter of more than 2800mm; on the other hand, relative to the correspondence between defect size and flaw detection equivalent established in the prior art, an artificially manufactured circular flat-bottom hole is used to characterize the size of the actual defect, and the sound path of the measurement process is adjusted to be consistent, and the probe angle is adjusted to make the sound beam perpendicular to the surface of the sample, so as to obtain a proportional relationship between the reflected wave amplitude and the defect area. The present invention simplifies the condition restrictions, expands the scope of application, and considers more factors and variables at the same time, thereby improving the detection accuracy of less than 0.1mm, especially less than 0.05mm.
[0057] Specifically, the method for obtaining the corresponding relationship between the dense defect size y and the dense defect equivalent x of the rotor forging to be tested in S2 includes:
[0058] S201: Select a rotor forging having the same volume, shape and material as the rotor forging to be tested as a candidate data source rotor forging;
[0059] S202: obtaining defect position information and defect equivalent information of the candidate data source rotor forging based on ultrasonic testing, selecting the candidate data source rotor forging with dense defects as the data source rotor forging, and recording the dense defect position information (defect depth information) and dense defect equivalent of the data source rotor forging;
[0060] S203: Based on the dense defect position information of the rotor forging of the data source, processing is performed to the depth plane where the defect is located, and dense defect size information corresponding to the dense defect position information is collected;
[0061] S204: Based on the dense defect size information corresponding to the dense defect equivalent, obtain the corresponding relationship between the dense defect size y and the dense defect equivalent x of the rotor forging to be tested.
[0062] It should be noted that in S201, a rotor forging having the same volume, shape and material as the rotor forging to be tested is selected as the alternative data source rotor forging to avoid the influence of different forging volumes, shapes and materials on the corresponding relationship between defect size y and dense defect equivalent x.
[0063] It should be noted that in S202, the existing ultrasonic flaw detection equipment can be used to perform flaw detection on the alternative data source rotor forgings, and the alternative data source rotor forgings with dense defects can be screened out as the data source rotor forgings; multiple data source rotor forgings can be screened out, and their own real dense defect size y and dense defect equivalent x are used as the source data set for obtaining the fitting relationship between y and x.
[0064] Specifically, the method for collecting dense defect size information corresponding to dense defect position information in S203 includes:
[0065] S2031, performing cold working and material extraction at the dense defect depth position based on the dense defect position information of the rotor forging of the data source;
[0066] S2032. Perform macroscopic structural inspection and inclusion analysis on the depth position of dense defects, and count the number and average size of inclusions in each layer.
[0067] Specifically, the cold working material extraction in S2031 includes grinding and polishing the data source rotor forging layer by layer.
[0068] Compared with the prior art, the present invention grinds and polishes the data source rotor forging layer by layer through cold working, which can retain the real defect information of the original rotor forging as much as possible and help improve the accuracy of the fitting relationship.
[0069] It should be noted that existing technologies, such as ultrasonic flaw detection technology, do not have sufficient accuracy and precision in detecting the true size of defects in rotor forgings, especially the size of dense defects, but can provide approximate defect depth information as a reference; therefore, in order to obtain the true size information of dense defects in S203, a cold working material collection method is adopted to expose the dense defects at the target depth to the visible field of view, and more objective and accurate technical means can be used to perform macroscopic structure detection and inclusion analysis to obtain the true size of dense defects; at the same time, combined with the dense defect equivalent information of the data source rotor forging obtained in S202, a source data set of the fitting relationship between the dense defect size y and the dense defect equivalent x can be constructed.
[0070] Specifically, in S204, existing analysis software may be used to fit the dense defect size y and the dense defect equivalent x to the source data set to obtain a fitting relationship between the two.
[0071] Specifically, the fitting relationship between the dense defect size y and the dense defect equivalent x of the rotor forging satisfies:
[0072] y=A1×exp(-x / t1)+y0;
[0073] Among them: y0, A1, t1 are constants;
[0074] y0=-7.115±0.35;
[0075] A1=11.49422±0.12;
[0076] t1=-0.65584±0.02; its confidence level R 2 ≥0.99565.
[0077] It should be noted that although the volume, shape and material of the selected data source rotor forgings are different, in the chromium-molybdenum alloy system for rotor forgings, the constants of the corresponding relationship between the defect size y and the dense defect equivalent x obtained by fitting the data source rotor forgings of different volumes, shapes and materials fluctuate reasonably within a small range, and the confidence level R 2 ≥0.99565, which shows that the above relationship has good accuracy and credibility, and has good applicability to the chromium-molybdenum alloy system for rotor forgings of different sizes and models.
[0078] Specifically, the macroscopic structure detection and inclusion analysis performed in S2032 include scanning electron microscope analysis and optical microscope analysis.
[0079] Example 1
[0080] This embodiment discloses a method for detecting a rotor forging with a micro-equivalent ultrasonic flaw detection, wherein a 25Cr2Ni2Mo1V generator rotor with a diameter of 2900 mm is selected as the rotor forging to be tested, comprising:
[0081] S1: Detecting the rotor forging to be tested using ultrasonic flaw detection equipment to obtain all defect positions (defect position depth) and defect equivalents of the defect in the rotor forging to be tested;
[0082] According to the definition of dense defects in JB / T5000.15-2007 "General Technical Requirements for Heavy Machinery Part 15: Nondestructive Testing of Forged Steel Parts", dense defects are screened out from all defects;
[0083] Specifically, dense defects are defined as five or more defect reflection signals occurring simultaneously within a 50mm sound path range on the fluorescent screen scanning line; or five or more defect reflection signals occurring within the same depth on a 50mm×50mm detection surface.
[0084] S2: obtaining a predicted dense defect size of the rotor forging to be tested based on the corresponding relationship between the defect size of the rotor forging to be tested and the dense defect equivalent;
[0085] S2 includes the step of obtaining the corresponding relationship between the dense defect size y and the dense defect equivalent x of the rotor forging to be tested, and the obtaining step includes:
[0086] S201: Select a rotor forging having the same volume, shape and material as the rotor forging to be tested as a candidate data source rotor forging;
[0087] S202: Use existing ultrasonic flaw detection equipment to perform flaw detection on the candidate data source rotor forging, obtain defect position information and defect equivalent information of the candidate data source rotor forging, select the candidate data source rotor forging with dense defects as the data source rotor forging, select the candidate data source rotor forging with dense defects as the data source rotor forging, and record the dense defect position information (defect depth information) and dense defect equivalent of the data source rotor forging;
[0088] S203: Based on the dense defect position information of the rotor forging of the data source, processing is performed to the depth plane where the defect is located, and dense defect size information corresponding to the dense defect position information is collected;
[0089] S2031, grinding and polishing the data source rotor forging layer by layer at the dense defect depth position based on the dense defect position information of the data source rotor forging;
[0090] S2032. Perform macroscopic structural inspection and inclusion analysis on the depth position of dense defects, and count the number and average size of inclusions in each layer.
[0091] S204: Using existing analysis software to fit the dense defect size y and the dense defect equivalent x to the source data set, and obtaining a fitting relationship between the two.
[0092] like Figure 2 As shown, the corresponding relationship between the defect size y and the dense defect equivalent x of the rotor forging to be tested obtained by the above method satisfies:
[0093] y=A1×exp(-x / t1)+y0
[0094] Among them: y0, A1, t1 are constants;
[0095] y0=-7.115;
[0096] A1=11.49422;
[0097] t1=-0.65584.
[0098] S3: Determine the defect level of the rotor forging to be tested based on the predicted dense defect size.
[0099] S4: In order to obtain the real dense defect size of the rotor forging to be tested, the rotor forging to be tested is subjected to ultrasonic flaw detection and the real dense defect size information of the rotor forging to be tested is obtained by following the steps below:
[0100] Based on the acquired information on the depth position of the dense defects of the rotor forging to be tested, the material is cold processed to different dense defect depth positions by grinding and polishing layer by layer;
[0101] Perform macroscopic structural inspection and inclusion analysis at the depth of dense defects, and count the number and average size of inclusions in each layer.
[0102] The actual size of the dense defects of the rotor forging to be tested obtained by S4 and the predicted size of the dense defects to be tested obtained by S2 are compared in the following Table 1:
[0103] Table 1 Prediction results of actual size of dense defects in rotor forgings to be tested and size of dense defects to be tested in Example 1
[0104]
[0105] Example 2
[0106] This embodiment discloses a method for detecting a rotor forging with a micro-equivalent ultrasonic flaw detection. The difference from the first embodiment is that the rotor forging to be tested has different sizes and materials. A 30Cr1Mo1V high-medium pressure rotor with a diameter of 700 mm is selected as the rotor forging to be tested, including:
[0107] S1: Detecting the rotor forging to be tested using ultrasonic flaw detection equipment to obtain all defect positions (defect position depth) and defect equivalents of the defect in the rotor forging to be tested;
[0108] According to the definition of dense defects in JB / T5000.15-2007 "General Technical Requirements for Heavy Machinery Part 15: Nondestructive Testing of Forged Steel Parts", dense defects are screened out from all defects;
[0109] Specifically, dense defects are defined as five or more defect reflection signals occurring simultaneously within a 50mm sound path range on the fluorescent screen scanning line; or five or more defect reflection signals occurring within the same depth on a 50mm×50mm detection surface.
[0110] S2: obtaining a predicted dense defect size of the rotor forging to be tested based on the corresponding relationship between the defect size of the rotor forging to be tested and the dense defect equivalent;
[0111] S2 includes the step of obtaining the corresponding relationship between the dense defect size y and the dense defect equivalent x of the rotor forging to be tested, and the obtaining step includes:
[0112] S201: Select a rotor forging having the same volume, shape and material as the rotor forging to be tested as a candidate data source rotor forging;
[0113] S202: Use existing ultrasonic flaw detection equipment to perform flaw detection on the candidate data source rotor forging, obtain defect position information and defect equivalent information of the candidate data source rotor forging, select the candidate data source rotor forging with dense defects as the data source rotor forging, select the candidate data source rotor forging with dense defects as the data source rotor forging, and record the dense defect position information (defect depth information) and dense defect equivalent of the data source rotor forging;
[0114] S203: Based on the dense defect position information of the rotor forging of the data source, processing is performed to the depth plane where the defect is located, and dense defect size information corresponding to the dense defect position information is collected;
[0115] S2031, grinding and polishing the data source rotor forging layer by layer at the dense defect depth position based on the dense defect position information of the data source rotor forging;
[0116] S2032. Perform macroscopic structural inspection and inclusion analysis on the depth position of dense defects, and count the number and average size of inclusions in each layer.
[0117] S204: Using existing analysis software to fit the dense defect size y and the dense defect equivalent x to the source data set, and obtaining a fitting relationship between the two.
[0118] like Figure 3 As shown, the corresponding relationship between the defect size y and the dense defect equivalent x of the rotor forging to be tested obtained by the above method satisfies:
[0119] y=A1×exp(-x / t1)+y0
[0120] Among them: y0, A1, t1 are constants;
[0121] y0=-7.442;
[0122] A1=11.58475;
[0123] t1=-0.66959.
[0124] S3: Determine the defect level of the rotor forging to be tested based on the predicted dense defect size.
[0125] S4: In order to obtain the real dense defect size of the rotor forging to be tested, the rotor forging to be tested is subjected to ultrasonic flaw detection and the real dense defect size information of the rotor forging to be tested is obtained by following the steps below:
[0126] Based on the acquired information on the depth position of the dense defects of the rotor forging to be tested, the material is cold processed to different dense defect depth positions by grinding and polishing layer by layer;
[0127] Perform macroscopic structural inspection and inclusion analysis at the depth of dense defects, and count the number and average size of inclusions in each layer.
[0128] The actual size of the dense defects of the rotor forging to be tested obtained by S4 and the predicted size of the dense defects to be tested obtained by S2 are compared in the following Table 2:
[0129] Table 2 Prediction results of actual size of dense defects in rotor forgings to be tested and size of dense defects to be tested in Example 2
[0130]
[0131]
[0132] It can be seen from the above that the rotor forging micro-equivalent ultrasonic flaw detection method of the present invention is applicable to rotor forgings with a diameter range of 700mm to 2900mm and different materials, and has good detection accuracy for micro-intensive defects less than 0.1mm, especially less than 0.05mm.
[0133] Comparative Example 1
[0134] This comparative example discloses a method for detecting a rotor forging with a micro-equivalent ultrasonic flaw detection. A 25Cr2Ni2Mo1V generator rotor with a diameter of 2900 mm is selected as the rotor forging to be tested. The difference from Example 1 is that the fitting relationship between the dense defect size y and the dense defect equivalent x is different, and satisfies:
[0135] y=A1×exp(-x / t1)+y0;
[0136] Among them: y0, A1, t1 are constants;
[0137] y0=-7.115;
[0138] A1=11.49422;
[0139] t1=-1.5.
[0140] The actual size of the dense defects of the rotor forging to be tested and the predicted results of the dense defect size are compared in the following Table 3:
[0141] Table 3 Comparative Example 1 The actual size of the dense defects in the rotor forging to be tested and the predicted size of the dense defects
[0142]
[0143]
[0144] Comparative Example 2
[0145] This comparative example discloses a method for detecting a rotor forging with a micro-equivalent ultrasonic flaw detection. A 25Cr2Ni2Mo1V generator rotor with a diameter of 2900 mm is selected as the rotor forging to be tested. The difference from Example 1 is that the fitting relationship between the dense defect size y and the dense defect equivalent x is different, and satisfies:
[0146] y=A1×exp(-x / t1)+y0;
[0147] Among them: y0, A1, t1 are constants;
[0148] y0=-7.115;
[0149] A1=15;
[0150] t1=-0.65584.
[0151] The actual size of the dense defects of the rotor forging to be tested and the predicted results of the dense defect size are compared in the following Table 4:
[0152] Table 4 Comparative Example 2 The actual size of the dense defects in the rotor forging to be tested and the predicted size of the dense defects
[0153]
[0154]
[0155] The results show that the maximum deviation between the predicted value and the actual value of the flaw detection method in Example 1-2 is 0.4-0.7 μm, which is much smaller than the maximum deviation between the predicted value and the actual value of Comparative Example 1 and Comparative Example 2, which is 8.4-13.3.
[0156] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.
Claims
1. A method for detecting rotor forgings by micro-equivalent ultrasonic flaw detection, characterized in that: include: S1: Obtain the dense defect equivalent of the defects of the rotor forging to be tested based on ultrasonic testing; S2: obtaining the defect position size of the rotor forging to be tested based on the corresponding relationship between the defect size of the rotor forging to be tested and the dense defect equivalent; S3: Determine the defect level of the rotor forging to be tested based on the number of potential defect locations and defect location sizes of the rotor forging to be tested.
2. The rotor forging micro-equivalent ultrasonic flaw detection method according to claim 1 is characterized in that: In the step S1, the dense defect equivalent is quantified by the AVG method.
3. The rotor forging micro-equivalent ultrasonic flaw detection method according to claim 2 is characterized in that: In the step S2, the corresponding relationship between the defect size y and the dense defect equivalent x of the rotor forging to be tested satisfies: y=A1×exp(-x / t1)+y0, wherein: y0, A1, t1 are constants.
4. The rotor forging micro-equivalent ultrasonic flaw detection method according to claim 3 is characterized in that: The y0=-7.115±0.
35.
5. The rotor forging micro-equivalent ultrasonic flaw detection method according to claim 4 is characterized in that: The A1=11.49422±0.
12.
6. The rotor forging micro-equivalent ultrasonic flaw detection method according to claim 5, characterized in that: The t1 = -0.65584 ± 0.
02.
7. The rotor forging micro-equivalent ultrasonic flaw detection method according to claim 1 or 2, characterized in that: Obtain the corresponding relationship between the defect size y and the dense defect equivalent x of the rotor forging to be tested in S2, including: S201: Select a rotor forging having the same volume, shape and material as the rotor forging to be tested as a candidate data source rotor forging; S202: obtaining defect position information and defect equivalent information of the candidate data source rotor forging based on ultrasonic testing, selecting the candidate data source rotor forging with dense defects as the data source rotor forging, and recording the dense defect position information and dense defect equivalent of the data source rotor forging; S203: Based on the dense defect position information of the rotor forging of the data source, processing is performed to the depth plane where the defect is located, and dense defect size information corresponding to the dense defect position information is collected; S204: Based on the dense defect size information corresponding to the dense defect equivalent, obtain the corresponding relationship between the defect size y and the dense defect equivalent x of the rotor forging to be tested.
8. The rotor forging micro-equivalent ultrasonic flaw detection method according to claim 7, characterized in that: The method for collecting dense defect size information corresponding to dense defect position information in step S203 includes: S2031, performing cold working and material extraction at the dense defect depth position based on the dense defect position information of the rotor forging of the data source; S2032. Perform macroscopic structural inspection and inclusion analysis on the depth position of dense defects, and count the number and average size of inclusions in each layer.
9. The rotor forging micro-equivalent ultrasonic flaw detection method according to claim 8, characterized in that: The cold processing material removal in the step S2031 includes grinding the data source rotor forging layer by layer.
10. The rotor forging micro-equivalent ultrasonic flaw detection method according to claim 8, characterized in that: The macroscopic structure detection and inclusion analysis performed in step S2032 include scanning electron microscope analysis and optical microscopic analysis.