Train wheel flaw detection method

Abstract

The invention discloses a train wheel flaw detection method. The method comprises the following steps: S1, providing a sample wheel; s2, ultrasonic flaw detection equipment is used for conducting radial ultrasonic flaw detection on the sample wheel, the size of a blind area of each part of the wheel tread is measured, and blind area data are obtained and comprise the maximum value of the blind area; s3, according to the blind area data, the wheel rolling allowance is formulated; s4, wheel rolling and heat treatment machining are conducted, and it is ensured that the tread allowance is not smaller than the maximum value of the blind area; s5, after the wheel is qualified through ultrasonic flaw detection, the tread of the wheel is subjected to finish machining treatment, and the allowance of the tread is removed; wherein a flat-bottomed hole extending in the radial direction is formed in a rim of the sample wheel, and a set distance is formed between the flat-bottomed hole and a tread of the sample wheel. According to the train wheel flaw detection method, no blind area of train wheel tread full-area ultrasonic flaw detection can be achieved, all internal manufacturing defects in a new wheel rail contact alternating stress action area can be found as far as possible, the wheel manufacturing level and service performance are improved, and the safety of the wheel in the running process is further improved; and the high-speed and heavy-load development requirements of a railway system can be better met.

Description

Technical Field

[0001] The present invention belongs to the technical field of railway wheel production methods. Specifically, the present invention relates to a method for detecting flaws in train wheels. Background Art

[0002] Trains rely on the rolling of wheel sets on rails to achieve parallel operation. Cracks in the wheel rim of a wheel set are one of the more common faults in integral rolled steel wheel sets. After a wheel set has been in use for a period of time or traveled a certain mileage, due to the influence of many factors during operation, various faults such as wear, abrasion, peeling, and cracks on the tread surface of the wheel set will occur, posing a great safety hazard to railway vehicles. Rim fracture (commonly known as "rim crack") is the most harmful fault among the common faults in wheel operation and may lead to train derailment. With the increase in load and operating speed, the risk of rim crack shows an increasing trend.

[0003] In the prior art, the detection means for manufacturing defects inside the wheel rim mainly rely on ultrasonic flaw detection, which can detect most manufacturing defects inside the wheel rim. However, due to the influence of the emission pulse of the ultrasonic flaw detector, the oscillation of the wafer, and the interface wave, the ultrasonic waves reflected by defects near the surface close to the probe are affected by the above factors and cannot be correctly identified, that is, a blind area of ultrasonic flaw detection is formed.

[0004] Generally, ultrasonic flaw detection of the rim part is usually carried out from the inner rim surface and the tread surface, and the probe arrangement is as Figure 4 shown. It can be seen that when performing axial ultrasonic flaw detection from the inner rim surface, the blind area is close to the inner rim surface. Therefore, the area of alternating contact stress between the wheel and the rail is far from the blind area of axial ultrasonic flaw detection, and axial flaw detection can effectively detect internal defects parallel to the inner rim surface; but when performing radial ultrasonic flaw detection from the tread surface, the blind area coincides with the area of alternating contact stress between the wheel and the rail, and it is very difficult to detect manufacturing defects parallel to the tread surface existing in the blind area of radial ultrasonic flaw detection.

[0005] Currently, the blind area during ultrasonic flaw detection is usually measured using a CSK-IA test block or a stepped test block method. However, there are the following problems with the blind area of ultrasonic flaw detection measured using the above two test blocks:

[0006] 1. Whether it is the CSK-IA test block or the stepped test block method, their detection surfaces are flat and can be in complete contact with the probe of ultrasonic flaw detection. Therefore, the blind areas measured by these two methods are smaller than the blind area during actual radial ultrasonic flaw detection of the wheel.

[0007] 2. Whether it is the CSK-IA test block or the stepped test block method, their detection sensitivity is lower than the sensitivity during ultrasonic flaw detection of the train wheel rim. Generally speaking, the higher the detection sensitivity of ultrasonic flaw detection, the larger the flaw detection blind area. Therefore, the blind areas measured by these two methods are smaller than the blind area during actual radial ultrasonic flaw detection of the wheel. Summary of the Invention

[0008] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for detecting flaws in train wheels, aiming to achieve non-blind-zone ultrasonic flaw detection in the entire area of the tread of train wheels.

[0009] To achieve the above object, the technical solution adopted by the present invention is as follows: A method for detecting flaws in train wheels, comprising the steps of:

[0010] S1. Provide a sample wheel;

[0011] S2. Use ultrasonic flaw detection equipment to perform radial ultrasonic flaw detection on the sample wheel, measure the size of the blind zones at various parts of the wheel tread, and obtain blind zone data, including the maximum value of the blind zones;

[0012] S3. According to the blind zone data, formulate the rolling allowance for the wheels;

[0013] S4. Perform wheel rolling and heat treatment processes to ensure that the tread allowance is not less than the maximum value of the blind zones;

[0014] S5. After the wheels pass the ultrasonic flaw detection, perform finish machining on the wheel tread to remove the tread allowance;

[0015] Wherein, a flat-bottomed hole extending radially is arranged inside the rim of the sample wheel, and there is a set distance between the flat-bottomed hole and the tread of the sample wheel.

[0016] The set distance is 1 - 20 mm.

[0017] The flat-bottomed hole extends radially from the inner circular surface of the rim towards the inside of the rim, and multiple flat-bottomed holes are provided.

[0018] The flat-bottomed holes are arranged in multiple circles, and each circle has multiple flat-bottomed holes. All the flat-bottomed holes in the same circle are evenly distributed circumferentially with the axis of the sample wheel as the center line.

[0019] In the longitudinal section of the rim, multiple flat-bottomed holes are arranged between the tread and the inner circular surface of the rim, and all the flat-bottomed holes are arranged in sequence along the axial direction of the sample wheel.

[0020] Multiple arrangement regions are arranged along the axial direction of the sample wheel, and multiple flat-bottomed holes are arranged in each arrangement region. The lengths of the flat-bottomed holes in different arrangement regions are different.

[0021] The distance between two adjacent flat-bottomed holes arranged between the tread and the inner circular surface of the rim is 4 - 7 mm.

[0022] The distance between two adjacent flat-bottomed holes arranged between the tread and the inner circular surface of the rim is 5 mm.

[0023] The diameter of the flat-bottomed hole is 1 - 3 mm.

[0024] The method for detecting flaws in train wheels of the present invention can achieve full - area ultrasonic flaw detection of the tread of train wheels without blind spots, discover as many internal manufacturing defects as possible in the area of the alternating stress of the wheel - rail contact of newly - manufactured wheels, improve the manufacturing level and service performance of wheels, further enhance the safety of wheels during the driving process, and better meet the development needs of the high - speed and heavy - load railway system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] This specification includes the following drawings, and the shown contents are respectively:

[0026] Figure 1 is a flowchart of the method for detecting flaws in train wheels of the present invention;

[0027] Figure 2 is a schematic structural diagram of a sample wheel;

[0028] Figure 3 is a schematic diagram of the influence of the tread shape on the ultrasonic beam;

[0029] Figure 4 is a schematic diagram of the arrangement of ultrasonic flaw - detection probes;

[0030] Figure 5 is a schematic diagram of the axial and radial ultrasonic flaw - detection blind spots;

[0031] The labels in the figure are: 1, tread; 2, flat - bottomed hole; 3, inner circular surface; 4, inner rim surface; 5, outer rim surface; 6, ultrasonic flaw - detection probe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The following is a more detailed description of the specific embodiments of the present invention with reference to the drawings, aiming to help those skilled in the art have a more complete, accurate, and in - depth understanding of the concept and technical solution of the present invention and facilitate its implementation.

[0033] As Figure 1 shown, the present invention provides a method for detecting flaws in train wheels, including the following steps:

[0034] S1. Provide a sample wheel;

[0035] S2. Use ultrasonic flaw - detection equipment to perform radial ultrasonic flaw detection on the sample wheel, measure the size of the blind spots at each part of the wheel tread, and obtain blind - spot data, including the maximum value of the blind spots;

[0036] S3. Determine the rolling allowance of the wheel according to the blind - spot data;

[0037] S4. Perform wheel rolling and heat - treatment processing to ensure that the tread allowance is not less than the maximum value of the blind spots;

[0038] After the wheels pass ultrasonic flaw detection, finish machining is performed on the treads of the wheels to remove the surplus on the treads.

[0039] Specifically, in the present invention, a sample wheel for measuring the blind zone of radial ultrasonic flaw detection of the wheel rim designed by the present invention is used to measure the size of the blind zone of each part of the tread during radial ultrasonic flaw detection of the wheel rim. Then, during the hot rolling design of the wheel, a reasonable rolling allowance for the wheel is formulated. After ultrasonic flaw detection, according to the size of the blind zone of ultrasonic flaw detection, the blind zone part of ultrasonic flaw detection is machined off, and finally, non-blind-zone full-area ultrasonic flaw detection of the tread is achieved.

[0040] The purpose of the present invention is to provide a method for eliminating the blind zone of radial ultrasonic flaw detection of train wheel rims, so as to discover as many internal manufacturing defects as possible in the area of the alternating stress of wheel-rail contact of newly manufactured wheels. And through the guidance of the present invention, the formulation of the wheel production rolling process and the machining process is carried out, further improving the safety of the wheels during driving and better meeting the development needs of the railway system for speed increase and heavy haul.

[0041] Therefore, by quantitatively detecting the blind zone of radial ultrasonic flaw detection, the blind zone existing in the radial ultrasonic flaw detection of the wheel rim is eliminated, the detection ability of ultrasonic flaw detection is improved, the internal manufacturing defects in the area of the alternating stress of wheel-rail contact of the wheel rim are discovered in time, the quality of the wheel products is improved, and the vehicle operation failures and even accidents caused by product quality problems are reduced, which plays an important role in improving the quality of wheel products. The timely discovery of the wheel rim crack defects reduces the harm brought by defects such as wheel rim cracks during train operation.

[0042] The tread of a train wheel, that is, the part in contact with the rail, is not a straight line but consists of multiple arcs and straight lines. Therefore, the sound beam emitted by the ultrasonic probe will be refracted when passing through the arc surface of the tread. When it enters the wheel rim again, the path of the sound beam changes, resulting in the unevenness of the sound beam incident on the wheel rim and not being perpendicular to the tread, as Figure 3 shown. The detection surface of the CSK-IA test block or the stepped test block method recommended in the existing conventional standards for measuring the blind zone of ultrasonic flaw detection is a straight line, so it can fit well with the surface of the ultrasonic flaw detection probe. Therefore, the blind zone measured by the test block does not have a complete guiding role for the radial ultrasonic flaw detection of the wheel, and a special sample wheel needs to be made according to the actual tread shape of the wheel to be detected to measure the actual size of the blind zone of radial ultrasonic flaw detection.

[0043] Internationally, the rejection criteria for ultrasonic flaw detection of train wheel rims generally are divided into three levels, namely the equivalent of a flat-bottomed hole with a diameter of φ1mm, the equivalent of a flat-bottomed hole with a diameter of φ2mm, and the equivalent of a flat-bottomed hole with a diameter of φ3mm. Also, since the blind zone of ultrasonic flaw detection is affected by the detection sensitivity of ultrasonic flaw detection, when the ultrasonic flaw detection rejection criteria are different, the sensitivity during the implementation of ultrasonic flaw detection will also change. Therefore, the blind zone of ultrasonic detection measured using a standard and general CSK-IA test block or the stepped test block method is usually larger than the actual radial ultrasonic flaw detection of the wheel.

[0044] Therefore, it is necessary to make a corresponding blind zone sample wheel for each part of the tread of the rim radial ultrasonic flaw detection according to the actual tread shape of the wheel to be inspected and the flaw detection sensitivity. In the above step S1, the structure of the sample wheel used is as Figure 2 shown. A flat-bottomed hole extending radially is provided inside the rim of the sample wheel, and there is a set distance h between the flat-bottomed hole and the tread of the sample wheel. This sample wheel has the greatest guiding effect on the detection results of the blind zone sample wheel for each part of the tread of the rim radial ultrasonic flaw detection, and the detection results are the most true and reliable.

[0045] As Figure 2 shown, the sample wheel includes a rim. The flat-bottomed hole extends radially from the inner circular surface of the rim towards the inside of the rim. Multiple flat-bottomed holes are provided. The axis of the flat-bottomed hole is perpendicular to the axis of the inner circular surface of the rim (i.e., the axis of the sample wheel and the rim). The inner circular surface of the rim is a cylindrical surface, which is the inner surface of the rim. The tread and the inner circular surface are located between the inner rim surface and the outer rim surface of the rim. The flat-bottomed hole does not extend to the tread. The starting point of the flat-bottomed hole is located on the inner circular surface, and the vertical distance between the end point of the flat-bottomed hole and the tread is the set distance. The set distance h is 1 - 20mm, and the diameter of the flat-bottomed hole is 1 - 3mm. Exemplarily, the diameter of the flat-bottomed hole can be 1mm, 2mm, or 3mm, as shown in Table 1.

[0046] Table 1 Flat-bottomed hole setting parameter table

[0047]

[0048] As Figure 2 shown, multiple circles of flat-bottomed holes are provided, and each circle has multiple flat-bottomed holes. All the flat-bottomed holes in the same circle are evenly distributed circumferentially with the axis of the sample wheel as the center line. In the longitudinal section of the rim (the section where the radial line of the rim and the axis are located), multiple flat-bottomed holes are arranged between the tread and the inner circular surface of the rim. These flat-bottomed holes are arranged axially in sequence along the sample wheel and are equally spaced. The distance a between two adjacent flat-bottomed holes arranged between the tread and the inner circular surface of the rim is 4 - 7mm. Exemplarily, the distance a between two adjacent flat-bottomed holes arranged between the tread and the inner circular surface of the rim can be 5mm.

[0049] As Figure 2As shown in the figure, a plurality of arrangement regions are arranged along the axial direction of the sample wheel. A plurality of flat-bottomed holes are arranged in each arrangement region. The lengths of the flat-bottomed holes in different arrangement regions are different, and the lengths of all the flat-bottomed holes in the same arrangement region are the same.

[0050] In the above step S2, a radial ultrasonic flaw detection is performed on the sample wheel using an ultrasonic flaw detection device. The ultrasonic flaw detection device includes an ultrasonic flaw detection probe. The ultrasonic flaw detection probe is arranged opposite to the tread surface of the sample wheel. The blind zone sizes of various parts of the wheel tread are measured by the ultrasonic flaw detection probe to obtain the maximum value of the tread blind zone.

[0051] In the above step S3, according to the obtained blind zone data, a hot rolling process for the wheel is designed, and a reasonable rolling allowance for the wheel is formulated. The rolling allowance of the wheel is greater than the maximum value of the blind zone; the rolling allowance should be large enough to ensure that the blind zone part can be machined off after ultrasonic flaw detection, while avoiding excessive material waste and increased processing costs. For example, when the maximum value of the blind zone of each part of the tread surface detected is 3 mm, a sufficient rolling allowance can be considered during rolling. For example, the rolling allowance of the wheel is set to 5 mm.

[0052] In the above step S4, when manufacturing the wheel, the formed blank is successively subjected to rolling and heat treatment processes. During the processing, it is ensured that the tread allowance of the wheel is not less than the maximum value of the blind zone. For example, the tread allowance is reserved ≥ 3 mm to ensure that ultrasonic flaw detection can be performed on the entire tread area.

[0053] In the above step S5, after the ultrasonic flaw detection is completed, the 3 mm tread allowance is machined off, then a radial full-area blind zone-free ultrasonic flaw detection can be ensured for the train wheel.

[0054] After the treatment of the above steps, a radial full-area blind zone-free ultrasonic flaw detection will be achieved for the wheel tread. This can not only improve the accuracy of the quality inspection of the wheel, but also reduce the safety risks caused by missed detection of defects.

[0055] Example 1:

[0056] In this embodiment, the diameter of the flat-bottomed hole is 1 mm. Using the sample wheel as shown in Figure 2 the maximum value of the blind zone of the tread ultrasonic flaw detection is measured to be 5 mm under the detection sensitivity of φ1 mm. Therefore, the tread rolling allowance of the same type of wheel is designed to be 10 mm. After rolling and heat treatment, after pre-processing the surface oxide scale, it is ensured that the tread allowance is still more than 5 mm for ultrasonic flaw detection. After the ultrasonic flaw detection is qualified, a further finish machining of 5 mm is performed, then it can be ensured that the tread area of the wheel has undergone a radial full-area ultrasonic flaw detection.

[0057] The present invention has been described by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above methods. As long as various non-substantive improvements are made by adopting the method concept and technical solution of the present invention; or without improvement, the above concept and technical solution of the present invention are directly applied to other occasions, they are all within the protection scope of the present invention.

Claims

1. A method for detecting flaws in railway wheels, characterized in that: Includes steps: S1. Provide sample rounds; S2. Use ultrasonic flaw detection equipment to perform radial ultrasonic flaw detection on the sample wheel, measure the size of the blind area of ​​each part of the wheel tread, and obtain the blind area data, including the maximum value of the blind area; S3. Formulate wheel rolling allowance according to blind area data; S4. Perform wheel rolling and heat treatment to ensure that the tread margin is not less than the maximum value of the blind area; S5. After the wheel passes the ultrasonic flaw detection, the wheel tread is finely processed to remove the tread excess; A flat-bottomed hole extending in the radial direction is arranged inside the rim of the sample wheel, and a set distance is provided between the flat-bottomed hole and the tread of the sample wheel.

2. The train wheel flaw detection method according to claim 1, characterized in that: The set distance is 1-20 mm.

3. The train wheel flaw detection method according to claim 1, characterized in that: The flat bottom hole starts from the inner circumferential surface of the rim and extends radially toward the inside of the rim, and a plurality of flat bottom holes are provided.

4. The train wheel flaw detection method according to claim 3, characterized in that: The flat-bottom holes are arranged in a plurality of circles, and each circle has a plurality of flat-bottom holes. All the flat-bottom holes in the same circle are evenly distributed along the circumferential direction with the axis of the sample wheel as the center line.

5. The train wheel flaw detection method according to claim 3, characterized in that: On the longitudinal section of the rim, a plurality of flat-bottom holes are arranged between the tread and the inner circumferential surface of the rim, and all the flat-bottom holes are arranged in sequence along the axial direction of the wheel.

6. The train wheel flaw detection method according to claim 5, characterized in that: A plurality of arrangement areas are arranged along the axial direction of the sample wheel, and a plurality of the flat-bottom holes are arranged in each arrangement area. The lengths of the flat-bottom holes in different arrangement areas are different.

7. The train wheel flaw detection method according to claim 5, characterized in that: The distance between two adjacent flat-bottom holes arranged between the tread and the inner circumferential surface of the rim is 4-7 mm.

8. The train wheel flaw detection method according to claim 5, characterized in that: The distance between two adjacent flat-bottom holes arranged between the tread and the inner circular surface of the rim is 5 mm.

9. The train wheel flaw detection method according to any one of claims 1 to 8, characterized in that: The diameter of the flat bottom hole is 1-3 mm.

Images