Railway axle variable-diameter area defect detection sample shaft

Abstract

The utility model provides a railway axle variable diameter area defect detection sample shaft which comprises a sample shaft body, and the sample shaft body comprises a plurality of artificial defect grooves arranged on a first variable diameter section body and artificial defect holes arranged on a second variable diameter section body and a third variable diameter section body. The railway axle variable diameter area defect detection device can realize comprehensive, specific and rapid determination of the railway axle variable diameter area defect detection effect, solves the problem of variable diameter area detection effect verification, and guarantees the overall quality of an axle.

Description

Technical Field

[0001] The utility model belongs to the field of nondestructive testing, and in particular relates to a sample shaft for detecting defects in a variable diameter area of ​​a railway axle. Background Art

[0002] The variable diameter area of ​​railway axles is prone to processing or raw material defects, which can easily lead to axle failure. Magnetic particle testing is usually used to detect surface and near-surface defects of axles, or ultrasonic testing is used to detect axle defects. However, due to the complex structure of the variable diameter area of ​​the axle and the forming process of this area is usually forging and then machining, the orientation of defects in this area is complex. Therefore, the defect detection effect of the variable diameter area of ​​the axle is difficult to verify. Utility Model Content

[0003] The utility model aims to provide a railway axle variable diameter region defect detection sample axle to solve the technical problem that the defect detection effect of the axle variable diameter region is difficult to verify.

[0004] In order to solve the above technical problems, the specific technical solutions of the utility model are as follows:

[0005] A railway axle variable diameter area defect detection sample shaft, the detection sample shaft comprises a sample shaft body, the sample shaft body comprises a first cylindrical section body, a third cylindrical section body and a second cylindrical section body arranged between the first cylindrical section body and the third cylindrical section body, a first variable diameter section body is installed on one side of the first cylindrical section body, a second variable diameter section body is installed on the other side of the first cylindrical section body, one side of the second cylindrical section body is connected to the second variable diameter section body, a third variable diameter section body is installed on one side of the third cylindrical section body, and the other side of the second cylindrical section body is connected to the third variable diameter section body, a plurality of artificial defect grooves are opened on the first variable diameter section body, and artificial defect holes are opened on the second variable diameter section body and the third variable diameter section body.

[0006] Therefore, the utility model designs a test sample shaft for the area according to the variable diameter area of ​​the axle, and designs artificial defects on the first cylindrical section, the second variable diameter section and the third variable diameter section. By designing such known artificial defects, the ultrasonic detection system can be verified or debugged before the formal inspection of the axle. If the ultrasonic detection system can accurately identify the artificial defect grooves and artificial defect holes during the verification process and can achieve the required signal-to-noise ratio and gain margin, it means that the ultrasonic detection system and the detection parameter settings can meet the detection requirements of typical orientation defects, which provides convenience and guarantee for the accuracy of subsequent axle inspection.

[0007] Furthermore, the length of the cross section of the artificial defect groove is 0.5 mm to 3 mm, and the width of the cross section of the artificial defect groove is 0.1 mm to 0.3 mm.

[0008] Furthermore, the artificial defect grooves are arranged circumferentially along the end surface of the first variable diameter cross-section body, and the artificial defect grooves include a first groove, a second groove, a third groove and a fourth groove.

[0009] Furthermore, the angle θ1 between the extension direction of the first groove and the axis of the sample shaft body is 0.5° to 5°, and the distance between the first groove and the outer circle boundary of the end surface of the first variable diameter section body is in the range of 1 mm to 30 mm;

[0010] The angle θ2 between the extension direction of the second groove and the axis of the sample shaft body is 5.5° to 10°, and the distance L2 between the second groove and the outer circular boundary of the end surface of the first variable diameter section body is 1mm to 30mm;

[0011] The angle θ3 between the extension direction of the third groove and the axis of the sample shaft body is 10.5° to 15°, and the distance L3 between the third groove and the outer circle boundary of the end surface of the first variable diameter section body is 1mm to 30mm;

[0012] The included angle θ4 between the extension direction of the fourth groove and the axis of the sample shaft body is 15.5° to 20°, and the distance L2 between the fourth groove and the outer circular boundary of the end surface of the first variable diameter section body is 1 mm to 30 mm.

[0013] The utility model provides a railway axle variable diameter area defect detection sample shaft with the following advantages: the utility model can achieve a comprehensive, specific and rapid determination of the variable diameter area defect detection effect of the railway axle, solve the problem of variable diameter area detection effect verification, and ensure the overall quality of the axle. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the structure of the sample shaft body of the utility model;

[0015] Figure 2 for Figure 1 Left view of

[0016] Figure 3 This is a schematic diagram of the structure of the artificial defect groove of the utility model;

[0017] Figure 4 It is a schematic diagram of the signal-to-noise ratio of the utility model;

[0018] Figure 5 This is a flow chart of the test verification method of the utility model.

[0019] Explanation of the markings in the figure: 1. First variable diameter section; 2. First cylindrical section; 3. Second variable diameter section; 4. Second cylindrical section; 5. Third variable diameter section; 6. Third cylindrical section; 7. Artificial defect groove; 8. Artificial defect hole; 9. Sample shaft body; 1-1. First groove; 1-2. Second groove; 1-3. Third groove; 1-4. Fourth groove. DETAILED DESCRIPTION

[0020] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings.

[0021] like Figure 1 As shown, a railway axle variable diameter area defect detection sample shaft of the present embodiment includes a sample shaft body 9, and the sample shaft body 9 includes a first cylindrical section body 2, a third cylindrical section body 6 and a second cylindrical section body 4 arranged between the first cylindrical section body 2 and the third cylindrical section body 6, a first variable diameter section body 1 is installed on one side of the first cylindrical section body 2, a second variable diameter section body 3 is installed on the other side of the first cylindrical section body 2, one side of the second cylindrical section body 4 is connected to the second variable diameter section body 3, one side of the third cylindrical section body 6 is installed with a third variable diameter section body 5, and the other side of the second cylindrical section body 4 is connected to the third variable diameter section body 5, a plurality of artificial defect grooves 7 are opened on the first variable diameter section body 1, and artificial defect holes 8 are opened on the second variable diameter section body 3 and the third variable diameter section body 5.

[0022] Specifically, Figures 1 to 3As shown, the length of the cross section of the artificial defect groove 7 is 0.5mm to 3mm, and the width of the cross section of the artificial defect groove 7 is 0.1mm to 0.3mm. The artificial defect grooves 7 are arranged circumferentially along the end surface of the first variable diameter section body 1, and the artificial defect grooves 7 include a first groove 1-1, a second groove 1-2, a third groove 1-3 and a fourth groove 1-4. The angle θ1 between the extension direction of the first groove 1-1 and the axis of the sample shaft body 9 is 0.5° to 5°, and the distance between the first groove 1-1 and the outer circular boundary of the end surface of the first variable diameter section body 1 ranges from 1mm to 30mm. The angle θ2 between the extension direction of the second groove 1-2 and the axis of the sample shaft body 9 is 5.5° to 10°, and the distance L2 between the second groove 1-2 and the outer circular boundary of the end surface of the first variable diameter section body 1 is 1mm to 30mm. The included angle θ3 between the extension direction of the third groove 1-3 and the axis of the sample shaft body 9 is 10.5° to 15°, and the distance L3 between the third groove 1-3 and the outer circular boundary of the end face of the first variable diameter section body 1 is 1mm to 30mm. The included angle θ4 between the extension direction of the fourth groove 1-4 and the axis of the sample shaft body 9 is 15.5° to 20°, and the distance L2 between the fourth groove 1-4 and the outer circular boundary of the end face of the first variable diameter section body 1 is 1mm to 30mm.

[0023] The machining process of the variable diameter area of ​​the railway axle is usually to forge into an inclined platform first and then locally machine it. According to the relative relationship between the orientation of the forging defect and the direction of the metal streamline, the defect orientation close to the variable diameter area surface is usually similar to the outer surface, that is, it is inclined at a certain angle to the axis of the axle. The inclination angle is related to the outer diameter of the straight area of ​​the axle and the outer diameter of the variable diameter area. Therefore, the angle between the artificial defect groove 7 and the axis of the sample shaft body 9 is determined to be in the range of 0° to 20°.

[0024] For defects at a certain depth or deeper below the surface of the variable diameter area of ​​the railway axle, the change of metal streamlines is not obvious, so the defect orientation may be parallel to the axis. At the same time, considering that defects close to the surface may not be inclined at a certain angle to the axle axis, the lower limit of the depth range of the artificial defect hole 8 from the bottom surface or surface is designed to be 5mm.

[0025] If the rectangular cross-section grooves and flat-bottom holes can be accurately identified during the verification process, and the required signal-to-noise ratio and gain margin can be achieved, it means that the ultrasonic detection system and the detection parameter settings can meet the detection needs of defects with typical orientations. The basic requirement for the signal-to-noise ratio is not less than 6dB, which is only applicable to cases where the defect orientation is unfavorable and the defect reflection surface is small. For cases where the sound beam is basically perpendicular or approximately perpendicular to the main reflection surface of the defect, the signal-to-noise ratio should not be less than 12dB. The gain margin is also related to the defect reflection surface and the defect orientation. When the defect reflection surface is small and the defect orientation is unfavorable, the gain margin is usually small.

[0026] like Figure 5 As shown, this embodiment also provides a test verification method for a railway axle variable diameter area defect detection sample shaft, comprising the following steps:

[0027] Step 1: Place the sample shaft body 9 on the roller or other roller mechanism of the ultrasonic detection system, and use partial immersion coupling or full immersion coupling to make the central axis of the sample shaft body 9 coaxial with the ultrasonic probe beam axis of the test system, and make the beam enter the first variable diameter section body 1, and the direction of the beam is the preset direction during actual detection. As a preferred method, the position of the probe should be adjusted according to the diameter of the variable diameter area of ​​the axle and the interface reflection, so that the second water / steel interface reflection signal is located after the first axle bottom surface reflection signal.

[0028] Use a probe connection line to connect the ultrasonic probe and the ultrasonic flaw detector, set the detection parameters, and make initial adjustments to the detection system. The ultrasonic probe is a conventional pulse reflection probe or a phased array probe or other types of ultrasonic probes, and the ultrasonic flaw detector is a type A, type B, type C, type D or comprehensive scanning display type flaw detector, or a phased array ultrasonic flaw detector. As a preferred method, the detection parameters should be set according to the actual ultrasonic detection parameters of the axle, and the initial adjustment of the detection system should also be adjusted according to the actual ultrasonic detection of the axle.

[0029] Step 2: Rotate the sample shaft body 9 so that the sound beam is incident on the artificial defect groove 7 in turn, and save the display signal and image of the artificial defect groove 7 in the ultrasonic detection system. Specifically, the maximum linear velocity vmax of the rotation should not be greater than DB·PRF / n, and DB is the -6dB sound beam width. Among them, PRF is the pulse repetition frequency, n is the number of continuous signals that trigger the alarm, the value of n is at least 3, and DB is the actual measured value. As a preferred method, start the roller rotation and drive the sample shaft body 9 to rotate at a linear speed of 20mm / s. During the detection process, the display signal and image can be recorded in the form of a strip chart, C scan combined with A scan, and ensure that the recorded signal and image can be extracted.

[0030] Step three, move the ultrasonic probe to make the sound beam incident on the artificial defect hole 8 of the second variable diameter cross-section body 3 and the third variable diameter cross-section body 5 respectively, and save the display signal and image of the artificial defect hole 8 in the ultrasonic detection system.

[0031] Step 4: Figure 4As shown in Table 1 below, the signal-to-noise ratio X1 of the sample shaft body 9 and the dB value (gain margin) X2 at which the system can continue to gain are obtained through the display signals and images of the artificial defect groove 7 and the artificial defect hole 8. X1 and X2 are compared with the standard signal-to-noise ratio parameter N1 and the gain margin parameter N2. If X1≥N1 and X2≥N2, proceed to step five, otherwise return to step one.

[0032] Specifically, the specific acceptance schemes for the signal-to-noise ratio and gain margin of rectangular cross-section grooves of different sizes and angles, and flat-bottom holes of different diameters and burial depths are different. The following are typical corresponding situations. For example, if N1=12dB and N2=20dB, if the signal-to-noise ratio X1 of the artificial defect groove 7 and the artificial defect hole 8 is 9dB and the gain margin X2 is 10dB, the verification fails. At this time, it is necessary to return to step 1 to re-debug the ultrasonic detection system by re-adjusting the ultrasonic detection technology, replacing the ultrasonic probe, replacing the ultrasonic flaw detector, or adjusting the detection parameters.

[0033] Step 5: Test the axle to be tested.

[0034] After adopting the above scheme, it is possible to achieve a comprehensive, specific and rapid determination of the defect detection effect in the variable diameter area of ​​the railway axle, solve the problem of verifying the detection effect in the variable diameter area, and ensure the overall quality of the axle.

[0035] Table 1 Railway axle variable diameter area defect test verification table

[0036]

[0037] It is understood that the present invention is described by some embodiments, and those skilled in the art are aware that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A railway axle variable diameter area defect detection sample shaft, characterized in that: The invention comprises a specimen shaft body (9), wherein the specimen shaft body (9) comprises a first cylindrical section body (2), a third cylindrical section body (6), and a second cylindrical section body (4) arranged between the first cylindrical section body (2) and the third cylindrical section body (6); a first variable diameter section body (1) is installed on one side of the first cylindrical section body (2); a second variable diameter section body (3) is installed on the other side of the first cylindrical section body (2); one side of the second cylindrical section body (4) is connected to the second variable diameter section body (3); a third variable diameter section body (5) is installed on one side of the third cylindrical section body (6); the other side of the second cylindrical section body (4) is connected to the third variable diameter section body (5); a plurality of artificial defect grooves (7) are provided on the first variable diameter section body (1); and artificial defect holes (8) are provided on the second variable diameter section body (3) and the third variable diameter section body (5).

2. The railway axle variable diameter area defect detection sample shaft according to claim 1, characterized in that: The length of the cross section of the artificial defect groove (7) is 0.5 mm to 3 mm, and the width of the cross section of the artificial defect groove (7) is 0.1 mm to 0.3 mm.

3. The railway axle variable diameter area defect detection sample shaft according to claim 1, characterized in that: The artificial defect grooves (7) are arranged circumferentially along the end surface of the first variable diameter cross-section body (1), and the artificial defect grooves (7) comprise a first groove (1-1), a second groove (1-2), a third groove (1-3) and a fourth groove (1-4).

4. The railway axle variable diameter area defect detection sample shaft according to claim 3, characterized in that: The included angle θ1 between the extension direction of the first groove (1-1) and the axis of the sample shaft body (9) is 0.5° to 5°, and the distance between the first groove (1-1) and the outer circular boundary of the end surface of the first variable diameter cross-section body (1) is in the range of 1 mm to 30 mm; The included angle θ2 between the extension direction of the second groove (1-2) and the axis of the sample shaft body (9) is 5.5° to 10°, and the distance L2 between the second groove (1-2) and the outer circular boundary of the end surface of the first variable diameter cross-section body (1) is 1 mm to 30 mm; The included angle θ3 between the extension direction of the third groove (1-3) and the axis of the sample shaft body (9) is 10.5° to 15°, and the distance L3 between the third groove (1-3) and the outer circular boundary of the end face of the first variable diameter cross-section body (1) is 1 mm to 30 mm; The angle θ4 between the extension direction of the fourth groove (1-4) and the axis of the sample shaft body (9) is 15.5° to 20°, and the distance L2 between the fourth groove (1-4) and the outer circular boundary of the end face of the first variable diameter cross-section body (1) is 1mm to 30mm.

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