Method for judging grinding burns of large and oversize bearings based on Barkhausen noise technology

Abstract

The invention discloses a method for judging grinding burn of a bearing based on a Barkhausen noise technology, which comprises the following steps of: adjusting Barkhausen noise equipment according to material characteristics, so that an optimal magnetization voltage ensures that a magnetoelastic value is in an optimal interval; selecting a bearing sample piece with the same material, heat treatment mode and grinding process as the to-be-tested workpiece; measuring the magnetoelastic values of the five sample pieces by using Barkhausen noise equipment, marking the positions of the burnt sample pieces with abnormal magnetoelastic values, then carrying out X-ray diffraction stress test on the positions, and carrying out threshold correlation on the measured magnetoelastic values and stress values to obtain a correlation threshold; the magnetoelastic value MP is compared to an associated threshold. The method has the advantages that the efficient and accurate method for judging the grinding burns of the large and super-large bearings is provided, the Barkhausen noise technology and the X-ray diffraction stress test are combined, rapid detection and accurate threshold value association are achieved, and the detection efficiency and reliability are improved.

Description

Technical Field

[0001] This invention relates to the field of bearing quality inspection technology, and more specifically to a method for determining grinding burns in large and extra-large bearings based on Barkhausen noise technology. Background Technology

[0002] Currently, the traditional method for quality inspection of large or extra-large bearings is a combination of pickling and Barkhausen testing. Pickling, primarily used to inspect grinding burn defects on raceway surfaces, requires chemical etching, posing environmental pollution risks and potentially causing surface wear. Barkhausen testing, as an electromagnetic non-destructive testing method, suffers from limitations in practical applications due to its reliance on expert experience in traditional signal processing methods, resulting in weak generalization capabilities and a tendency to miss or misdetect bearings, especially under complex conditions. The combined use of these two methods not only prolongs the inspection cycle but also further reduces efficiency due to the complexity of the operational process, failing to meet the demands of modern industry for rapid and accurate inspection of large bearings. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a method for determining grinding burns in large and extra-large bearings based on Barkhausen noise technology. By optimizing the adjustment mode of the Barkhausen noise equipment and establishing a correlation threshold between magnetoelastic value and residual stress, the method can quickly and accurately determine grinding burns in bearings without relying on acid pickling, thus solving the problems of environmental pollution, low efficiency, and reliance on expert experience in traditional detection methods.

[0004] To achieve the above objectives, the present invention provides the following technical solution, comprising the following steps: Step 1, adjusting the Barkhausen noise equipment according to the material characteristics, ensuring that the optimal magnetization voltage of the Barkhausen noise equipment guarantees that the magnetoelastic value falls within the optimal range; Step 2, selecting bearing samples with the same material, heat treatment method, and grinding process as the workpiece to be tested, selecting two "acceptable" samples, two "edge" samples, and one "defect" sample; Step 3, using the Barkhausen noise equipment to measure the magnetoelastic values ​​of the five samples in Step 2, marking the abnormal magnetoelastic value locations of the samples with burns, and then performing X-ray diffraction stress testing on these locations, and correlating the measured magnetoelastic values ​​with the stress values ​​to obtain a correlation threshold; Step 4, comparing the magnetoelastic value MP with the correlation threshold obtained in Step 3, if the magnetoelastic value MP ≥ the correlation threshold, then the workpiece to be tested is determined to have burns; if the magnetoelastic value MP < the correlation threshold, then the workpiece to be tested is determined to have no burns.

[0005] As a further improvement of the present invention, the specific steps for adjusting the Barkhausen noise device in step one are as follows: Step one-one, take two workpieces to be tested, and perform high-temperature tempering on one of them so that the hardness difference between the two is about 20 HRC; Step one-two, place both samples in the device at the same time, start the "magnetization voltage scanning mode", and let the device automatically cover different magnetization voltage levels; Step one-three, the device software will record the magnetization voltage change values ​​of the two samples under each voltage in real time, and record the voltage level with the largest difference between the two; Step one-four, set the magnetization voltage corresponding to the largest difference as the final working parameter of the device, and complete the adjustment.

[0006] As a further improvement of the present invention, in step three, the magnetoelastic values ​​of the five samples in step two are measured using a Barkhausen noise instrument. Abnormal magnetoelastic values ​​are marked on the samples with burns. X-ray diffraction stress testing is then performed on these locations. The measured magnetoelastic values ​​and stress values ​​are correlated with a threshold to obtain the correlation threshold. The specific steps are as follows: Step three-one: The magnetoelastic values ​​of the five samples in step two are measured using a Barkhausen noise instrument. Locations with abnormal magnetoelastic values ​​in "defective" and "edge" samples are marked, and the magnetoelastic values ​​at the abnormal locations are recorded. Step three-two: X-ray diffraction stress testing is performed on the abnormal locations to measure the residual stress values ​​of the "defective" and "edge" samples. Residual stress is then measured on the "acceptable" samples as well, yielding three sets of magnetoelastic and residual stress values ​​for different degrees of burns. The data are plotted to obtain the correlation between the magnetoelastic values ​​and the residual stress measured by X-ray diffraction. Combined with the residual stress limits set in the manufacturing process, the correlation threshold is obtained.

[0007] The beneficial effects of this invention are that, compared to the traditional combination of acid pickling and Barkhausen testing, this invention achieves pure electromagnetic non-destructive testing by establishing a correlation threshold between magnetoelastic values ​​and residual stress, eliminating the need for chemical reagents and fundamentally eliminating environmental pollution risks and surface wear problems. Simultaneously, by replacing expert experience judgment with standardized threshold determination logic, the consistency and reliability of test results are significantly improved, with testing efficiency increased by more than 50% compared to traditional methods. Further improved equipment adjustment steps ensure optimal setting of magnetization voltage parameters, improving the stability of magnetoelastic value measurement; the refined threshold correlation steps enhance the accuracy of determining different degrees of burns, providing an efficient and environmentally friendly technical solution for the quality control of large bearings. Attached Figure Description

[0008] Figure 1 A diagram for quickly determining the optimal magnetization voltage; Figure 2 This is a schematic diagram showing the correlation between the magnetoelastic value and the residual stress measured by X-ray diffraction. Detailed Implementation

[0009] The present invention will now be described in further detail with reference to the embodiments shown in the accompanying drawings.

[0010] Reference Figure 1 As shown in this embodiment, a method for determining grinding burns in large and extra-large bearings based on Barkhausen noise technology includes the following steps: Step 1, adjusting the Barkhausen noise equipment according to material characteristics to ensure that the optimal magnetization voltage of the Barkhausen noise equipment ensures that the magnetoelastic value falls within the optimal range; Step 2, selecting bearing samples with the same material, heat treatment method, and grinding process as the workpiece to be tested, selecting two "acceptable" samples, two "edge" samples, and one "defect" sample; Step 3, using the Barkhausen noise equipment to measure the magnetoelastic values ​​of the five samples in Step 2, marking the abnormal magnetoelastic value locations of the samples with burns, and then performing X-ray diffraction stress testing on these locations, and correlating the measured magnetoelastic values ​​with the stress values ​​to obtain a correlation threshold; Step 4, comparing the magnetoelastic value MP with the correlation threshold obtained in Step 3, if the magnetoelastic value MP ≥ the correlation threshold, the workpiece to be tested is determined to have burns; if the magnetoelastic value MP < the correlation threshold, the workpiece to be tested is determined to have no burns. Step one involves adjusting the equipment to ensure signal stability; step two involves selecting multiple sample types to cover different burn conditions; and step three involves establishing a correlation threshold based on X-ray diffraction stress testing (e.g., ...). Figure 1 The residual stress limit corresponds to the magnetoelastic value, allowing the judgment process in step four to be completed without relying on acid pickling corrosion. This process eliminates the chemical treatment time of the acid pickling step, avoids missed or incorrect detections caused by differences in the judgment of corrosion effect in traditional methods, and achieves standardized detection through objective data correlation, solving the problems of environmental pollution, low efficiency, and reliance on expert experience in the background technology.

[0011] Furthermore, refer to Figure 1 As shown, the specific steps for adjusting the Barkhausen noise analyzer in Step 1 are as follows: Step 11: Take two workpieces to be tested, and perform high-temperature tempering on one of them to make the hardness difference between the two approximately 20 HRC; Step 12: Place both samples in the analyzer simultaneously and start the "magnetization voltage scanning mode" to allow the analyzer to automatically cover different magnetization voltage levels; Step 13: The analyzer software will record the changes in magnetization voltage of the two samples under each voltage in real time, and record the voltage level with the largest difference in changes; Step 14: Set the magnetization voltage corresponding to the largest difference as the final operating parameter of the analyzer, completing the adjustment. By manufacturing comparative samples with significant differences in hardness, the analyzer can quickly locate the magnetization voltage most sensitive to changes in material properties, solving the problem of traditional analyzer parameter adjustment relying on manual trial and error, and improving the efficiency of analyzer calibration and detection sensitivity.

[0012] Furthermore, refer to Figure 2As shown, the specific steps for obtaining the correlation threshold in step three are as follows: Step three-one: Use a Barkhausen noise meter to measure the magnetoelastic values ​​of the five samples from step two, mark the locations where the magnetoelastic values ​​of "defective" and "edge" samples are abnormal, and record the magnetoelastic values ​​at the abnormal locations; Step three-two: Perform X-ray diffraction stress testing on the abnormal locations to measure the residual stress values ​​of the "defective" and "edge" samples. Subsequently, residual stress is also measured on the "acceptable" samples to obtain three sets of magnetoelastic and residual stress value data for different burn degrees. Plot the data to obtain the correlation between the magnetoelastic value and the residual stress measured by X-ray diffraction. Combined with the residual stress limit set in the production process, the correlation threshold is obtained. By introducing X-ray diffraction stress testing as a benchmark, a quantitative relationship between the magnetoelastic value and the actual stress state is established, upgrading the Barkhausen test results from relative value judgment to absolute value judgment, enhancing the universality of testing different batches and different materials of workpieces, and solving the technical bottleneck of weak generalization ability of traditional Barkhausen testing.

[0013] The following example is provided in this embodiment: The selected sample was a GCr15 bearing ring of a certain model. The magnetoelastic and residual stress values ​​of the bearing ring were measured for three groups of different burn levels (no burn, slight burn, and severe burn), as shown in Table 1. Combined with the residual stress limit of -200MPa set in the manufacturing process, the residual stress values ​​and magnetoelastic values ​​were correlated with threshold values, as shown in Table 1. Figure 2 As shown, a residual stress value of -200MPa corresponds to a magnetoelastic value of 150. When the magnetoelastic value of the produced ring sample is greater than 150, it is a sample with burns ("defective" sample, "edge" sample), and when it is less than 150, it is a sample without burns ("acceptable" sample). Therefore, a magnetoelastic value of 150 for GCr15 rings is the judgment threshold, which is also the correlation threshold.

[0014] Table 1 Measurement results of magnetoelasticity and residual stress values In summary, this invention employs a three-stage detection scheme: "equipment parameter optimization - multi-state sample testing - stress correlation threshold establishment." By adjusting the optimal magnetization voltage of the Barkhausen noise equipment and selecting characteristic samples to establish a correlation threshold between magnetoelastic values ​​and residual stress, purely electromagnetic non-destructive testing of grinding burns in large and extra-large bearings is achieved. This scheme completely eliminates the acid pickling method, solving the problems of environmental pollution, low efficiency, and reliance on expert experience in traditional testing. Furthermore, through automated equipment adjustment and data-driven threshold determination, it significantly improves detection accuracy and stability, meeting the needs of modern industry for rapid quality screening of large bearings.

[0015] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for determining grinding burns in large and extra-large bearings based on Barkhausen noise technology, characterized in that: Includes the following steps: Step 1: Adjust the Barkhausen noise equipment according to the material properties so that the optimal magnetization voltage of the Barkhausen noise equipment ensures that the magnetoelastic value falls within the optimal range. Step 2: Select bearing samples with the same material, heat treatment method, and grinding process as the workpiece to be tested. Select two "acceptable" samples, two "edge" samples, and one "defect" sample. Step 3: Use a Barkhausen noise instrument to measure the magnetoelastic values ​​of the five samples from Step 2, mark the abnormal magnetoelastic values ​​of the samples with burns, and then perform X-ray diffraction stress testing at the location. Correlate the measured magnetoelastic values ​​with the stress values ​​to obtain the correlation threshold. Step 4: Compare the magnetoelastic value MP with the correlation threshold obtained in Step 3. If the magnetoelastic value MP ≥ the correlation threshold, the workpiece to be tested is determined to have burns; if the magnetoelastic value MP < the correlation threshold, the workpiece to be tested is determined to have no burns.

2. The method for determining grinding burns in large and extra-large bearings based on Barkhausen noise technology according to claim 1, characterized in that: The specific steps for adjusting the Barkhausen noise equipment in step one are as follows: Step 1: Take two workpieces to be tested, and temper one of them at high temperature so that the hardness difference between the two is about 20 HRC. Steps 1 and 2: Place both samples in the device simultaneously and start the "magnetization voltage scanning mode" to allow the device to automatically cover different magnetization voltage levels; Step 1 and Step 3: The equipment software will record the changes in magnetization voltage of the two samples under various voltages in real time, and record the voltage level with the largest difference in the changes between the two samples. Step 14: Set the magnetization voltage corresponding to the largest difference as the final operating parameter of the device to complete the adjustment.

3. The method for determining grinding burns in large and extra-large bearings based on Barkhausen noise technology according to claim 1 or 2, characterized in that: In step three, the magnetoelastic values ​​of the five samples from step two are measured using a Barkhausen noise meter. Locations with abnormal magnetoelastic values ​​in samples showing burns are marked. X-ray diffraction stress testing is then performed at these locations. The measured magnetoelastic values ​​are then correlated with stress values ​​to obtain the correlation threshold. The specific steps for obtaining the correlation threshold are as follows: Step 31: Use the Barkhausen noise instrument to measure the magnetoelastic values ​​of the five samples from Step 2, mark the locations where the magnetoelastic values ​​of the "defective" and "edge" samples are abnormal, and record the magnetoelastic values ​​at the abnormal locations. Step 32: Perform X-ray diffraction stress testing on abnormal locations to measure the residual stress values ​​of "defective" and "edge" samples. Then, perform residual stress measurement on "acceptable" samples as well to obtain three sets of magnetoelastic values ​​and residual stress values ​​for different degrees of burns. Plot the data into a graph to obtain the correlation between the magnetoelastic value and the residual stress measured by X-ray diffraction. Combined with the residual stress limit set in the manufacturing process, obtain the correlation threshold.

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