High-sensitivity test block for magnetic particle detection of high-iron carbon alloy structural steel bearing ring

Abstract

The invention provides a high-sensitivity test block for magnetic particle detection of a high-iron carbon alloy structural steel bearing ring, which comprises a base material A for simulating defects of an inner ring of a detected bearing and a base material B for simulating defects of an outer ring of the detected bearing, the base material A and the base material B are respectively provided with an outer cylindrical surface, and four circumferential small holes are formed in the outer cylindrical surfaces of the base material A and the base material B at intervals; the outer cylindrical surface is provided with four circumferential small holes, the hole diameters and the depths of the four circumferential small holes are equal, the outer cylindrical surface corresponding to the four circumferential small holes is provided with a cutting plane, the four cutting planes are the same in boundary dimension, the four circumferential small holes are parallel to the corresponding cutting planes, and the distances between the four circumferential small holes and the vertical lines of the corresponding cutting planes are different; and four axial small holes are sequentially formed in one end face of the base material A and one end face of the base material B at intervals in the anticlockwise direction. The test block provided by the invention can detect four flaw detection sensitivities of railway and high-speed rail bearing magnetic powder flaw detection, is visual in display, and solves the problem that an artificial defect on a traditional sensitivity test block does not correspond to an actual defect to be detected.

Description

Technical Field

[0001] This invention relates to bearing testing technology, specifically a high-sensitivity test block for magnetic particle testing of high-speed iron carbon alloy structural steel bearing rings. Background Technology

[0002] Magnetic particle testing is an important non-destructive testing method for detecting surface and near-surface defects in bearings. In the magnetic particle testing of high-speed railway rolling bearing parts, sensitivity test pieces are commonly used to determine the sensitivity of the magnetic particle testing, thereby obtaining the accuracy of the test.

[0003] Because the maximum magnetic permeability of the sensitivity test piece and the part differs, the applied magnetic field strength required to reach magnetic saturation also differs. Magnetic markings on the test piece do not fully represent magnetic saturation on the part, nor can they determine the depth at which defects can be detected. Based on these factors, existing magnetic particle testing sensitivity test blocks for high-speed rail carbon alloy structural steel bearings have the following problems: 1. Insufficient simulated defect types; 2. When verifying sensitivity in two directions on the part, only one simulated defect is present in each direction, requiring highly experienced personnel to make correct judgments. These two points result in a high probability of missed and false detections in existing magnetic particle testing of high-speed rail carbon alloy structural steel bearings.

[0004] Therefore, developing a high-sensitivity test block for magnetic particle testing of high-speed railway bearings to improve the sensitivity, detection accuracy, and detection rate of magnetic particle testing of high-speed railway bearings has become an urgent task. Summary of the Invention

[0005] To address the problems raised in the background art, the purpose of this invention is to provide a high-sensitivity test block for magnetic particle testing of high-speed railway carbon alloy structural steel bearing rings. This block can detect four magnetic particle testing sensitivities on the inner and outer rings of high-speed railway bearings, and the display is intuitive, overcoming the shortcomings of traditional sensitivity test pieces, such as incomplete detection and low detection efficiency. During the magnetization process, there are no human factors affecting the display of magnetic traces, resulting in high reliability and improved detection rate of near-surface defects, effectively ensuring the reliability of railway bearing quality.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A high-sensitivity magnetic particle testing block for high-speed railway carbon alloy structural steel bearing rings includes a test block A simulating an inner ring defect and a test block B simulating an outer ring defect. Both test blocks A and B have an outer cylindrical surface. Four circumferential holes are spaced apart on the outer cylindrical surface of both test blocks A and B. The diameter and depth of the four circumferential holes are equal. A cutting plane is provided at the corresponding outer cylindrical surface of each of the four circumferential holes. The four cutting planes have the same external dimensions. The four circumferential holes are parallel to their respective cutting planes, and the perpendicular distances between the four circumferential holes and their respective cutting planes are different. Four axial holes are spaced apart in a counter-clockwise direction on one end face of both test blocks A and B. The diameter and depth of the four axial holes are equal, and the perpendicular distances between the four axial holes and their respective outer cylindrical surfaces are different.

[0007] The test block A is a frustum-shaped structure with an internal axial through hole. The large-diameter end of the conical surface of the test block A has a coaxial first annular boss, and the small-diameter end of the conical surface of the test block A has a coaxial second annular boss. The four circumferential holes of the test block A are arranged in a counterclockwise direction at intervals in the outer cylindrical surface of the first annular boss. The four axial holes of the test block A are all located on the end face of the first annular boss. The diameters of the four circumferential holes and the four axial holes of the test block A are all equal.

[0008] The four circumferential holes of the test block A include holes A, B, C, and D. Holes A, B, C, and D are all flat-bottomed cylindrical blind holes, and the perpendicular distances between the midpoints of the axes of holes A, B, C, and D and the corresponding cutting planes increase sequentially. The four axial holes of the test block A include holes E, F, G, and H. Holes E, F, G, and H are all flat-bottomed cylindrical through holes, and the shortest perpendicular distances between holes E, F, G, and H and the outer cylindrical surface of the first annular boss increase sequentially.

[0009] The shortest perpendicular distances from the midpoints of the axes of holes A, B, C, and D to the outer cylindrical surface of the first annular boss are 0.8+R1mm, 1.2+R1mm, 1.6+R1mm, and 2.0+R1mm, respectively. The openings of holes A, B, C, and D are all provided with right-angled process grooves. The shortest perpendicular distances from the axes of holes E, F, G, and H to the outer cylindrical surface of the first annular boss are 0.8+R1mm, 1.2+R1mm, 1.6+R1mm, and 2.0+R1mm, respectively. R1 is the radius of holes A, B, C, D, E, F, G, and H.

[0010] The diameter of holes A, B, C, D, E, F, G, and H is 1.1 mm. With the center of test block A as the center, holes A, B, C, and D are spaced 30° apart, and holes E, F, G, and H are spaced 10° apart. The depth of holes A, B, C, and D is 15 mm.

[0011] The test block B is a circular ring structure. The four circumferential holes of the test block B are arranged sequentially and spaced apart along the axial direction in the outer cylindrical surface of the test block B. The four axial holes of the test block B are all located on one end face of the test block B. The diameter and depth of the four circumferential holes and the four axial holes of the test block B are equal.

[0012] The four circumferential holes of the test block B include holes I, J, K, and L. Holes I, J, K, and L are all flat-bottomed cylindrical blind holes, and the perpendicular distances from the midpoints of the axes of holes I, J, K, and L to the corresponding cutting planes increase sequentially. The four axial holes of the test block B include holes M, N, O, and P. Holes M, N, O, and P are all flat-bottomed cylindrical blind holes, and the shortest perpendicular distances from holes M, N, O, and P to the outer cylindrical surface of the test block B increase sequentially.

[0013] The shortest perpendicular distances between the midpoints of the axes of holes I, J, K, and L and the outer cylindrical surface of test block B are 0.8+R2mm, 1.2+R2mm, 1.6+R2mm, and 2.0+R2mm, respectively. The openings of holes I, J, K, and L are all provided with right-angled process grooves. The shortest perpendicular distances between the axes of holes M, N, O, and P and the outer cylindrical surface of test block B are 0.8+R2mm, 1.2+R2mm, 1.6+R2mm, and 2.0+R2mm, respectively. R2 is the radius of holes I, J, K, L, M, N, O, and P.

[0014] The diameter of holes I, J, K, L, M, N, O, and P is 1.1 mm, and the depth is 15 mm. Holes I, J, K, and L are spaced 13 mm apart. Holes E, F, G, and H are spaced 10° apart, with the center of test block B as the center.

[0015] The innovation and contribution of this invention lie in the following: The test block proposed in this invention can detect four flaw detection sensitivities in magnetic particle testing of railway high-speed rail bearing rings, and the display is intuitive, overcoming the problem of discrepancies between artificial defects and actual defects to be detected in traditional sensitivity test pieces. During the magnetization process, there are no human factors affecting the display of magnetic traces, resulting in high reliability and improved detection rate of near-surface defects, ensuring the reliability of railway high-speed rail bearing quality. By analyzing the depth of the holes displaying magnetic traces from the surface, the depth detectable by magnetic particle testing can be determined. Furthermore, the invention has a relatively simple structure and low cost, making it suitable for widespread use. Attached Figure Description

[0016] Figure 1 This is the front view of test block A.

[0017] Figure 2 for Figure 1The left-side view.

[0018] Figure 3 This is the front view of test block B.

[0019] Figure 4 for Figure 3 The left-side view.

[0020] Figure 5 This is a simulation method for existing artificial hole defects in the outer ring of high-speed rail bearings; Figure 6 This invention provides a method for simulating artificial hole defects in the outer ring of a high-speed rail bearing.

[0021] In the figure, 1. Hole A, 2. Hole B, 3. Hole C, 4. Hole D, 5. Hole E, 6. Hole F, 7. Hole G, 8. Hole H, 9. Hole I, 10. Hole J, 11. Hole K, 12. Hole L, 13. Hole M, 14. Hole N, 15. Hole O, 16. Hole P, 17. Test block B, 18. Test block A, 19. Cutting plane, 20. First annular boss. Detailed Implementation

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0023] like Figure 1-6 As shown, this invention provides a high-sensitivity test block for magnetic particle testing of high-speed railway carbon alloy structural steel bearing rings, including a test block A corresponding to simulate inner ring defects. In one embodiment of this invention, test block A has four circumferential holes and four axial holes. A cutting plane is provided on the outer cylindrical surface corresponding to each of the four circumferential holes. The maximum outer diameter of test block A is 260.5 mm, and the diameters of the four circumferential holes and four axial holes are all 1.1 mm. Test block A is a frustum-shaped structure with an internal axial through hole. The large-diameter end of the conical surface of test block A has a coaxial first annular boss, and the small-diameter end of the conical surface of test block A has a coaxial second annular boss. The four circumferential holes of test block A are all located within the outer cylindrical surface of the first annular boss, and the four axial holes of test block A are all located on the end face of the first annular boss. The diameters of the four circumferential holes and the four axial holes of test block A are all equal. The axes of the four circumferential holes on test block A are perpendicular to the axis of the first annular boss on test block A.

[0024] The four circumferential holes of the test block A include holes A, B, C, and D. Holes A, B, C, and D are all flat-bottomed cylindrical blind holes, and the perpendicular distances between the midpoints of the axes of holes A, B, C, and D and the corresponding cutting planes increase sequentially. The four axial holes of the test block A include holes E, F, G, and H. Holes E, F, G, and H are all flat-bottomed cylindrical through holes, and the shortest perpendicular distances between holes E, F, G, and H and the outer cylindrical surface of the first annular boss increase sequentially.

[0025] The shortest perpendicular distances from the midpoints of the axes of holes A, B, C, and D to the outer cylindrical surface of the first annular boss are 0.8+0.55mm, 1.2+0.55mm, 1.6+0.55mm, and 2.0+0.55mm, respectively. The openings of holes A, B, C, and D are all provided with right-angled process grooves. The shortest perpendicular distances from the axes of holes E, F, G, and H to the outer cylindrical surface of the first annular boss are 0.8+0.55mm, 1.2+0.55mm, 1.6+0.55mm, and 2.0+0.55mm, respectively. R1 is the radius of holes A, B, C, D, E, F, G, and H.

[0026] Centered on the center of test block A, holes A, B, C and D are spaced 30° apart, and holes E, F, G and H are spaced 10° apart; the depth of holes A, B, C and D is 15 mm.

[0027] The high-sensitivity magnetic particle testing block for high-speed rail carbon alloy structural steel bearing rings also includes a test block B corresponding to simulate outer ring defects. In one embodiment of the invention, test block B is an overall annular structure with an outer diameter of 310 mm. Test block B has four circumferential holes and four axial holes, all with equal diameters. A cutting plane is provided on the outer cylindrical surface corresponding to each of the four circumferential holes. The four circumferential holes of test block B are all located within the outer cylindrical surface of test block B, and the four axial holes of test block B are all located on one end face of test block B. The diameter and depth of the four circumferential holes and the four axial holes of test block B are equal. The axes of the four circumferential holes on test block B are perpendicular to the axis of test block B.

[0028] The four circumferential holes of the test block B include holes I, J, K, and L. Holes I, J, K, and L are all flat-bottomed cylindrical blind holes, and the perpendicular distances from the midpoints of the axes of holes I, J, K, and L to the corresponding cutting planes increase sequentially. The four axial holes of the test block B include holes M, N, O, and P. Holes M, N, O, and P are all flat-bottomed cylindrical blind holes, and the shortest perpendicular distances from holes M, N, O, and P to the outer cylindrical surface of the test block B increase sequentially.

[0029] The shortest perpendicular distances between the midpoints of the axes of holes I, J, K, and L and the outer cylindrical surface of test block B are 0.8+R2mm, 1.2+R2mm, 1.6+R2mm, and 2.0+R2mm, respectively. The openings of holes I, J, K, and L are all provided with right-angled process grooves. The shortest perpendicular distances between the axes of holes M, N, O, and P and the outer cylindrical surface of test block B are 0.8+R2mm, 1.2+R2mm, 1.6+R2mm, and 2.0+R2mm, respectively. R2 is the radius of holes I, J, K, L, M, N, O, and P.

[0030] The diameter of holes I, J, K, L, M, N, O, and P is 1.1 mm, and the depth is 15 mm. Holes I, J, K, and L are also axially spaced on the outer cylindrical surface of test block B, with a 13 mm interval between them. Hole I is 16 mm from the end face of test block B. Holes M, N, O, and P are spaced 10° apart.

[0031] Since the inner and outer rings of the high-speed rail bearings are made of G20CrNi2MoA, a high-quality low-carbon alloy structural steel, both test blocks A and B were made of G20CrNi2MoA. After carburizing and heat treatment, the test block surfaces have high hardness and wear resistance. After quenching, the surfaces are under compressive stress, exhibiting high contact fatigue strength.

[0032] like Figure 5 As shown, after machining artificial holes on the surface of a traditional bearing outer ring test block, the distance between the left side of the artificial hole and the upper surface is greater than that on the right side due to the surface curvature. Under the same magnetization state, the leakage magnetic field generated on the right side will also be larger, resulting in a clearer magnetic trace. This can affect the operator's judgment and the debugging of the equipment.

[0033] like Figure 6 As shown, in the test block of the present invention, test block B is cut on the side of the simulated defect artificial hole, so that the distance of the artificial hole from the upper surface 19 is consistent along the entire axial direction. In the magnetized state, a uniform magnetic trace can be formed, which is beneficial for the operator's observation and adjustment.

[0034] Method of using this invention: The magnetic particle testing equipment is a specialized device that utilizes the principle of electromagnetic induction. When an electric current is applied to the central conductor and the yoke, a magnetic field is generated, magnetizing the ferromagnetic workpiece. When defects are present on or near the surface of the workpiece, leakage magnetic field is generated at the defect location. This leakage magnetic field attracts magnetic powder, forming magnetic traces at the defect. For ease of observation, fluorescent magnetic powder is used, producing easily observable magnetic traces under ultraviolet light. Test blocks A and B are identical in material, size, and condition to the part being tested.

[0035] Before testing the parts, select either test block A or test block B to verify the magnetization process and current and magnetic potential parameters according to the model of the parts to be tested (if the model of the parts to be tested and test block A are the same, test block A is used and test block B is not used; if the model of the parts to be tested and test block B are the same, test block B is used and test block A is not used; if the bearing products are being tested, test block A and test block B can be combined to form the structure of the corresponding bearing products and used simultaneously).

[0036] Taking test block A as an example, during use, test block A is placed on the test station of the professional magnetic particle testing equipment. Test block A can be rotated at a uniform speed by rollers to facilitate the uniform spraying of magnetic suspension liquid onto the surface of test block A. The range of circumferential current and axial magnetomotive force parameters is obtained through calculation, and the current and magnetomotive force values ​​within the calculation range are set. After starting the equipment, the magnetic rod passes through the axial through hole of test block A. After being energized, a circumferential magnetic field is generated to detect axial defects perpendicular to the magnetic field. The axial small hole simulates axial defects. When the magnetic yoke located outside test block A is energized, an axial magnetic field is generated to detect circumferential defects perpendicular to the magnetic field. The circumferential small hole simulates circumferential defects. After being energized, a circular or elliptical composite magnetic field generated by the magnetic rod and magnetic yoke, whose size and direction change periodically with the current frequency, completes the magnetization of test block A. The magnetic suspension liquid spray switch and the test block rotation switch are turned on. Under ultraviolet light, after the magnetic suspension liquid is uniformly covered on the surface of the test block, the magnetization and magnetic trace observation of test block A are completed according to the testing process. When the simulated defects are sprayed with magnetic suspension, the small holes attract magnetic powder, forming easily observable magnetic traces. The clarity of these magnetic traces verifies the sensitivity of the magnetic particle detection and confirms the detection process and parameters. If the magnetic trace at a specific location on the surface of a small hole in test block A is continuous and clear, the detection sensitivity of the corresponding process can be confirmed. The depth and detectable range of the defect can be determined by observing the magnetic traces corresponding to the hole locations. For example, when using test block A, observe the magnetic traces on the surfaces corresponding to holes A, B, C, and D in sequence. If the magnetic traces in holes A and B are continuous and clear, while those in hole C are unclear and those in hole D are discontinuous, the detection sensitivity can be determined to be the same as that corresponding to hole B, i.e., the circumferential detection sensitivity is 1.2 mm from the surface.

[0037] This invention reduces the influence of human factors in the magnetic particle testing process by drilling holes in the test block. The holes make the magnetic traces more intuitive, overcoming the problem of mismatch between the test piece display and the defect being tested in traditional testing, resulting in higher reliability. It also reduces the amount of test piece consumables used, saving an estimated 3-5 sets of dedicated test pieces per year. Four circumferential holes and four axial holes can simultaneously verify the detection sensitivity of eight defects in two vertical directions. Holes at different depths from the surface can simultaneously verify the sensitivity of defects at four depths, solving the problem of verifying the sensitivity of a single test piece. In use, the detection sensitivity of the magnetic particle test can be judged by changing the excitation current density and the magnetic flux inside the test block, based on the clarity of the magnetic traces displayed in different holes. Setting multiple defect simulation holes shortens the number of parameter settings required for magnetic particle testing, improving detection efficiency and accuracy. This invention increases the detection sensitivity for near-surface defects, improving their detection rate. The detection of near-surface defects can help improve processes, reduce scrap rates, and better ensure the reliability of railway and high-speed rail bearings, with an estimated annual reduction in scrap rates due to near-surface defects of approximately one ten-thousandth.

[0038] The innovation and contribution of this invention lies in: adjusting the material thickness of the outer portion of the artificial hole location, so that even on a circumferential surface, the simulated inner surface defect is consistent in distance from the outer surface; the test block provided by this invention can determine four detection sensitivities at distances of 0.8mm, 1.2mm, 1.6mm, and 2mm from the surface in both circumferential and axial directions during magnetic particle testing of high-speed rail carbon alloy structural steel bearings, and the display is intuitive, overcoming the problem of discrepancies between artificial defects and actual defects in traditional sensitivity test pieces. During the magnetization process, there are no human factors affecting the display of magnetic traces, resulting in high reliability. Furthermore, the structure of this invention is relatively simple and inexpensive, making it suitable for widespread use.

[0039] The parts of this invention not described in detail are prior art.

Claims

1. A high sensitivity test block for magnetic particle testing of high carbon ferrous alloy structural steel bearing ring, comprising a test block A simulating defects of the inner ring of the bearing under test and a test block B simulating defects of the outer ring of the bearing under test, characterized in that: Both test blocks A and B have an outer cylindrical surface. Four circumferential holes are spaced apart within the outer cylindrical surface of both test blocks A and B. The diameter and depth of the four circumferential holes are equal. A cutting plane is provided at the corresponding location on the outer cylindrical surface of each of the four circumferential holes. The four cutting planes have the same external dimensions. The four circumferential holes are parallel to their respective cutting planes, and the perpendicular distances between the four circumferential holes and their corresponding cutting planes are all different. Four axial holes are spaced apart in a counter-clockwise direction on one end face of both test blocks A and B. The diameter and depth of the four axial holes are equal, and the perpendicular distances between the four axial holes and their respective outer cylindrical surfaces are all different.

2. The high-sensitivity test block for magnetic particle testing of high-speed railway carbon alloy structural steel bearing rings according to claim 1, characterized in that: The test block A is a frustum-shaped structure with an internal axial through hole. The large-diameter end of the conical surface of the test block A has a coaxial first annular boss, and the small-diameter end of the conical surface of the test block A has a coaxial second annular boss. The four circumferential holes of the test block A are arranged in a counterclockwise direction at intervals in the outer cylindrical surface of the first annular boss. The four axial holes of the test block A are all located on the end face of the first annular boss. The diameters of the four circumferential holes and the four axial holes of the test block A are all equal.

3. The high-sensitivity test block for magnetic particle testing of high-speed railway carbon alloy structural steel bearing rings according to claim 2, characterized in that: The four circumferential holes of the test block A include holes A, B, C, and D. Holes A, B, C, and D are all flat-bottomed cylindrical blind holes, and the perpendicular distances between the midpoints of the axes of holes A, B, C, and D and the corresponding cutting planes increase sequentially. The four axial holes of the test block A include holes E, F, G, and H. Holes E, F, G, and H are all flat-bottomed cylindrical through holes, and the shortest perpendicular distances between holes E, F, G, and H and the outer cylindrical surface of the first annular boss increase sequentially.

4. The high-sensitivity test block for magnetic particle testing of high-speed railway carbon alloy structural steel bearing rings according to claim 3, characterized in that: The shortest perpendicular distances from the midpoints of the axes of holes A, B, C, and D to the outer cylindrical surface of the first annular boss are 0.8+R1mm, 1.2+R1mm, 1.6+R1mm, and 2.0+R1mm, respectively. The openings of holes A, B, C, and D are all provided with right-angled process grooves. The shortest perpendicular distances from the axes of holes E, F, G, and H to the outer cylindrical surface of the first annular boss are 0.8+R1mm, 1.2+R1mm, 1.6+R1mm, and 2.0+R1mm, respectively. R1 is the radius of holes A, B, C, D, E, F, G, and H.

5. The high-sensitivity test block for magnetic particle testing of high-speed railway carbon alloy structural steel bearing rings according to claim 3, characterized in that: The diameter of holes A, B, C, D, E, F, G, and H is 1.1 mm. With the center of test block A as the center, holes A, B, C, and D are spaced 30° apart, and holes E, F, G, and H are spaced 10° apart. The depth of holes A, B, C, and D is 15 mm.

6. The high-sensitivity test block for magnetic particle testing of high-speed railway carbon alloy structural steel bearing rings according to claim 1, characterized in that: The test block B is a circular ring structure. The four circumferential holes of the test block B are arranged sequentially and spaced apart along the axial direction in the outer cylindrical surface of the test block B. The four axial holes of the test block B are all located on one end face of the test block B. The diameter and depth of the four circumferential holes and the four axial holes of the test block B are equal.

7. The high-sensitivity test block for magnetic particle testing of high-speed railway carbon alloy structural steel bearing rings according to claim 6, characterized in that: The four circumferential holes of the test block B include holes I, J, K, and L. Holes I, J, K, and L are all flat-bottomed cylindrical blind holes, and the perpendicular distances from the midpoints of the axes of holes I, J, K, and L to the corresponding cutting planes increase sequentially. The four axial holes of the test block B include holes M, N, O, and P. Holes M, N, O, and P are all flat-bottomed cylindrical blind holes, and the shortest perpendicular distances from holes M, N, O, and P to the outer cylindrical surface of the test block B increase sequentially.

8. The high-sensitivity test block for magnetic particle testing of high-speed railway carbon alloy structural steel bearing rings according to claim 6, characterized in that: The shortest perpendicular distances between the midpoints of the axes of holes I, J, K, and L and the outer cylindrical surface of test block B are 0.8+R2mm, 1.2+R2mm, 1.6+R2mm, and 2.0+R2mm, respectively. The openings of holes I, J, K, and L are all provided with right-angled process grooves. The shortest perpendicular distances between the axes of holes M, N, O, and P and the outer cylindrical surface of test block B are 0.8+R2mm, 1.2+R2mm, 1.6+R2mm, and 2.0+R2mm, respectively. R2 is the radius of holes I, J, K, L, M, N, O, and P.

9. A high-sensitivity test block for magnetic particle testing of high-speed railway carbon alloy structural steel bearing rings according to claim 7, characterized in that: The diameter of holes I, J, K, L, M, N, O, and P is 1.1 mm, and the depth is 15 mm. Holes I, J, K, and L are spaced 13 mm apart. Holes E, F, G, and H are spaced 10° apart, with the center of test block B as the center.

Images