ULTRASONIC MACHINING METHOD FOR IMPROVING ABRADABILITY OF WHEEL OF LOCOMOTIVE, AND APPLICATIONS

Abstract

An ultrasonic machining method to improve the wear resistance of locomotive wheels includes ultrasonic machining by ultrasonic machining tool head on the wheel rim and/or surface of the tread that is rotated along the main axis. The ultrasonic machining method mentioned in the invention can not only process the locomotive wheel just after leaving factory, but also repair the worn locomotive wheel. After machining the rim and/or tread of the locomotive wheel with ultrasonic machining, the surface tensile stress of the rim and/or the tread surface will become compressive stress, the surface roughness will be greatly reduced, and the ideal compressive stress will be preset on the surface.

Claims

1. An ultrasonic machining method for improving the wear resistance of locomotive wheels, wherein the method includes of locomotive wheel rim ultrasonic machining, that is using the ultrasonic machining tool head to process the surface of the rim rotating along the main axis.

2. The ultrasonic machining method for improving the wear resistance of locomotive wheels according to claim 1, its characteristics is that while ultrasonic processing is performed on the rim of the locomotive wheel, the tread of the locomotive wheel is also subjected to ultrasonic machining, that is, ultrasonic processing is performed on the surface of the tread rotating along the main spindle by using an ultrasonic machining tool head.

3. The ultrasonic machining method for improving the wear resistance of locomotive wheels according to claim 1, its characteristics is that the locomotive wheel is a new locomotive wheel or a worn locomotive wheel.

4. The ultrasonic machining method for improving the wear resistance of locomotive wheels according to claim 1, its characteristic is that when the locomotive wheels are worn, ultrasonic machining of the wheel rim or tread of the locomotive wheels is processed after semi-finishing is performed.

5. The ultrasonic machining method for improving the wear resistance of locomotive wheels according to claim 1, its characteristic is that the wheel rim and/or tread of the locomotive wheels are semi-finished, which means make the surface roughness of the wheel rim or tread surface is 3.2-10 m.

6. The ultrasonic machining method for improving the wear resistance of locomotive wheels according to claim 1, its characteristic is that the parameters of the ultrasonic machining are: the rotation speed of the spindle is 5-45 r/min, the feed rate is 0.03-0.2 mm/r, the pressure of ultrasonic machining tool head on processing surface is 300-3000 N.

7. The ultrasonic machining method for improving the wear resistance of locomotive wheels according to claim 1, its characteristic is that the parameters of the ultrasonic machining are: the rotation speed of the spindle is 19 r/min, the feed rate is 0.1 mm/r, the pressure of ultrasonic machining tool head on processing surface is 1200 N.

8. The ultrasonic machining method for improving the wear resistance of locomotive wheels according to claim 1, its characteristic is that when ultrasonic machining is performed on the surface of the rim rotating along the main shaft and the surface of the tread using an ultrasonic machining tool head, the number of rounds of the ultrasonic machining is 1-3 times.

9. The ultrasonic machining method for improving the wear resistance of locomotive wheels according to claim 1, its characteristic is that when ultrasonic machining is performed on the surface of the rim rotating along the main shaft and the surface of the tread using an ultrasonic machining tool head, the amplitude of the ultrasonic machining is 5-25 m.

10. The application of ultrasonic machining method to improve the wear resistance of locomotive wheels according to claim 1: ultrasonic machining is performed on areas in which the locomotive wheels should be worn out. The parameters of the ultrasonic machining are: the rotation speed of the spindle is 5-45 r/min, the feed amount is 0.03-0.2 mm/r, and the pressure of ultrasonic machining tool head on processing surface is 300-3000N; the choice to get better results is: a semi-finishing process is performed before ultrasonic machining in the worn area, make the surface roughness of area to be processed is 3.2-0 m. The ultrasonic machining parameters are as follows, the rotation speed of the spindle is 19 r/min, the feed rate is 0.1 mm/r, the pressure of ultrasonic machining tool head on processing surface is 1200 N.

Description

DESCRIPTION OF FIGURES

[0023] FIG. 1 is the processing diagram of the locomotive wheel by ultrasonic machining method.

[0024] FIG. 2 shows the schematic diagram of the area to be machined on the locomotive wheels, where the region with dashed lines is the area to be processed.

[0025] FIG. 3a shows the metallographic image after ultrasonic machining of the processing surface by different ultrasonic machining pressure:

[0026] FIG. 3b shows the metallographic image after ultrasonic machining of the processing surface by different ultrasonic machining pressure:

[0027] FIG. 3c shows the metallographic image after ultrasonic machining of the processing surface by different ultrasonic machining pressure;

[0028] FIG. 3d shows the metallographic image after ultrasonic machining of the processing surface by different ultrasonic machining pressure;

[0029] FIG. 3e shows the metallographic image after ultrasonic machining of the processing surface by different ultrasonic machining pressure.

[0030] In FIG. 1 and FIG. 2. Label 1 means ultrasonic machining tool head. Label 2 means rim. Label 3 means read and the dotted line area in Label 4 refers to the area of ultrasonic processing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] The following describes the present invention in detail with reference to the embodiments and the accompanying drawings, but is not limited thereto.

[0032] As shown in FIG. 1-2.

Embodiment 1

[0033] An ultrasonic machining method for improving the wear resistance of locomotive wheels, including: ultrasonic machining of locomotive wheel rim 2, it is ultrasonic machining of the surface of the rim 2 which is rotating along the spindle with an ultrasonic machining tool head 1. The locomotive wheel is the factory-fresh locomotive wheel.

Embodiment 2

[0034] As described in embodiment 1, an ultrasonic machining method to improve the wear resistance of locomotive wheels. The difference is that the ultrasonic machining parameters are: the rotation speed of the spindle is 5-45 r/min, the feed rate is 0.03-0.2 mm/r, the pressure of ultrasonic machining tool head on processing surface is 300-3000 N.

Embodiment 3

[0035] As described in embodiment 1, an ultrasonic machining method to improve the wear resistance of locomotive wheels, the difference is that the locomotive wheel is worn.

[0036] When the locomotive wheels are worn out, the wheel rim 2 of the semi-finished locomotive wheels is processed by ultrasonic machining.

[0037] The wheel rim 2 of the locomotive wheel is semi-finished, make the surface roughness of the wheel rim 2 is 3.2-10 m.

Embodiment 4

[0038] As described in embodiment 1-3, an ultrasonic machining method to improve the wear resistance of locomotive wheels, the difference is that when the surface of the rim 2 rotating along the spindle is machined using an ultrasonic machining tool head 1, the number of ultrasonic machining is 1-3.

Embodiment 5

[0039] As described in embodiment 1-3, an ultrasonic machining method to improve the wear resistance of locomotive wheels, the difference is that when the surface of the rim 2 rotating along the spindle is machined using an ultrasonic machining tool head 1, the amplitude of ultrasonic machining is 5-25 m.

Embodiment 6

[0040] An ultrasonic machining method for improving the wear resistance of locomotive wheels, including: ultrasonic machining of locomotive wheel rim 2 and tread 3, it is ultrasonic machining of the surface of the rim 2 and tread 3 which are rotating along the spindle with an ultrasonic machining tool head 1. The locomotive wheel is the factory-fresh locomotive wheel.

Embodiment 7

[0041] As described in embodiment 6, an ultrasonic machining method to improve the wear resistance of locomotive wheels. The difference is that the ultrasonic machining parameters are: the rotation speed of the spindle is 5-45 r/min, the feed rate is 0.03-0.2 mm/r, the pressure of ultrasonic machining tool head on processing surface is 300-3000 N.

Embodiment 8

[0042] As described in embodiment 1, an ultrasonic machining method to improve the wear resistance of locomotive wheels, the difference is that the locomotive wheel is worn.

[0043] When the locomotive wheels are worn out, the wheel rim 2 and tread 3 of the semi-finished locomotive wheels are processed by ultrasonic machining.

[0044] The wheel rim 2 and tread 3 of the locomotive wheel are semi-finished, make the surface roughness of the wheel rim 2 and tread is 3.2-10 m.

Embodiment 9

[0045] As described in embodiment 1-8, an ultrasonic machining method to improve the wear resistance of locomotive wheels. The difference is that the ultrasonic machining parameters are: the rotation speed of the spindle is 19 r/min, the feed rate is 0.1 mm/r, the pressure of ultrasonic machining tool head 1 on processing surface is 1200 N.

[0046] As the present embodiment, the pressure of ultrasonic machining tool head on processing surface is: 100 N, 300 N, 1200 N, 3000 N and 3500 N respectively. The mean residual stresses of the wheel rim after processing are as follows:

TABLE-US-00001 Average Sample/sample processing parameters residual stress Wheel rim without ultrasonic processing. 17.68 Ultrasonic processing pressure 100 N 55.21 Ultrasonic processing pressure 300 N 98.7 Ultrasonic processing pressure 1200 N 176.07 Ultrasonic processing pressure 3000 N 212.93 Ultrasonic processing pressure 3500 N 277.04

[0047] FIG. 3a is an equilibrium diagram of the rim surface when the ultrasonic processing tool head surface pressure is 100 N.

[0048] FIG. 3b is an equilibrium diagram of the rim surface when the ultrasonic processing tool head surface pressure is 300 N.

[0049] FIG. 3c is an equilibrium diagram of the rim surface when the ultrasonic processing tool head surface pressure is 1200 N.

[0050] FIG. 3d is an equilibrium diagram of the rim surface when the ultrasonic processing tool head surface pressure is 3000 N.

[0051] FIG. 3e is an equilibrium diagram of the rim surface when the ultrasonic processing tool head surface pressure is 3500 N.

Embodiment 10

[0052] An application of the ultrasonic machining method to improve the wear resistance of locomotive wheels using the method describes in embodiment 1-9: Ultrasonic machining is performed on areas in which the locomotive wheels should be worn out. The parameters of the ultrasonic machining are: the rotation speed of the spindle is 5-45 r/min, the feed rate is 0.03-0.2 mm/r, and the pressure of ultrasonic machining tool head on processing surface is 300-3000 N.

Embodiment 11

[0053] As described in embodiment 10, an application of improve the wear resistance of locomotive wheels, the difference is that before the ultrasonic machining of the worn area, turning to semi-finishing, make its surface roughness is 3.2-10 m.

Embodiment 12

[0054] As described in embodiment 10, an application of improve the wear resistance of locomotive wheels, the difference is that the ultrasonic machining parameters are: the rotation speed of the spindle is 19 r/min, the feed rate is 0.1 mm/r, the pressure of ultrasonic machining tool head 1 on processing surface is 1200 N.

Test Comparison Example

[0055] The experimental comparison of the locomotive wheels after processing in the implementation example 9 is as follows:

[0056] In the process of ultrasonic machining on the surface of the locomotive wheels, the factors affecting the machining effects include spindle speed, feed rate, and pressure. The above three factors are used as test factors in this test and are denoted as A (corresponding to spindle speed), B (corresponding feed rate) and C (corresponding pressure). In this experiment, each factor has three levels, namely:

[0057] The corresponding three criteria for A (corresponding spindle speed) include: A.sub.1=5 r/min, A.sub.2=19 r/min. A.sub.3=45 r/min.

[0058] The corresponding three criteria for B (corresponding feed rate) include: B.sub.1=0.03 mm/r. B.sub.2=0.1 mm/r, B.sub.3=0.2 mm/r.

[0059] The corresponding three criteria for C (corresponding pressure) include: C.sub.1=300 N, C.sub.2=1200 N, C.sub.3=3000 N.

TABLE-US-00002 TABLE 1 test parameters of ultrasonic machining which is applied to abrasion resistance of locomotive wheels. Surface Hard- Spindle Feed rough- Hard- ness speed rate Pressure ness ness increase No. (r/min) (mm/r) (N) (m) (HL) (HL) Remark 1 5 0.03 300 0.07 461 101 2 5 0.03 1200 0.05 482 122 3 5 0.03 3000 0.08 498 138 4 5 0.1 300 0.09 452 92 5 5 0.1 1200 0.06 495 135 6 5 0.1 3000 0.09 505 145 7 5 0.2 300 0.12 433 73 8 5 0.2 1200 0.11 481 121 9 5 0.2 3000 0.13 494 134 10 19 0.03 300 0.06 460 100 11 19 0.03 1200 0.05 485 125 12 19 0.03 3000 0.06 495 135 13 19 0.1 300 0.09 450 90 14 19 0.1 1200 0.05 490 130 Optimum 15 19 0.1 3000 0.07 510 150 16 19 0.2 300 0.12 435 75 17 19 0.2 1200 0.09 485 125 18 19 0.2 3000 0.10 499 139 19 45 0.03 300 0.1 428 68 20 45 0.03 1200 0.06 498 138 21 45 0.03 3000 0.09 507 147 22 45 0.1 300 0.1 456 96 23 45 0.1 1200 0.06 485 125 24 45 0.1 3000 0.08 492 132 25 45 0.2 300 0.13 432 72 26 45 0.2 1200 0.12 488 128 27 45 0.2 3000 0.15 499 139

[0060] The test data of table 1 shows that when A (corresponding spindle speed) is selected as A.sub.2=19 r/min, B (corresponding feed rate) is selected as B.sub.2=0.1 mm/r, and C (corresponding pressure) is selected as C.sub.2=1200 N, the best surface roughness is obtained, hardness and the increase of hardness are also the highest value.

[0061] Combining the orthogonal test to analyze the above data to verify whether A (corresponding spindle speed) is selected as A.sub.2=19 r/min, B (corresponding feed rate) is selected as B.sub.2=0.1 mm/r, and C (corresponding pressure) is selected as C.sub.2=1200 N, will obtain the best surface roughness, and hardness and the increase of hardness are also the highest value.

[0062] Orthogonal Test Data Analysis:

[0063] A.sub.1=5 r/min, A.sub.2=19 r/min, A.sub.3=45 r/min.

[0064] The corresponding three criteria of B (corresponding feed rate) include: B.sub.1=0.03 mm/r, B.sub.2=0.1 mm/r, B.sub.3=0.2 mm/r.

[0065] The corresponding three criteria of C (corresponding pressure) include: C.sub.1=300 N, C.sub.2=1200 N, C.sub.3=3000 N.

TABLE-US-00003 TABLE 2 table of three test factors Experimental factors Level Spindle speed (r/min) A Feed rate (mm/r) B Pressure (N) C 1 A.sub.1 = 5 r/min B.sub.1 = 0.03 mm/r C.sub.1 = 300 N 2 A.sub.2 = 19 r/min B.sub.2 = 0.1 mm/r C.sub.2 = 1200 N 3 A.sub.3 = 45 r/min B.sub.3 = 0.2 mm/r C.sub.3 = 3000 N

[0066] According to the orthogonal test data method, L.sub.9(3.sup.4) or L.sub.27(3.sup.13) can be used. Because the test only considers the influence of three factors on the machining effect of the wheel surface and does not consider the interaction between the factors, therefore. L.sub.9 (3.sup.4) orthogonal table was selected.

[0067] The orthogonal test scheme (table 3) was formed by filling the horizontal values of each factor in the orthogonal table of L.sub.9 (3.sup.4).

TABLE-US-00004 TABLE 3 orthogonal test scheme Experimental result The total wear rate of Factors rail and wheel (%) Spindle Feed rate Pressure Sliding No. speed (r/min) (mm/r) (N) wear Rolling wear 1 5 0.03 300 1.23 1.20 2 5 0.1 1200 0.83 0.85 3 5 0.2 3000 0.99 1.02 4 19 0.03 1200 1.04 1.02 5 19 0.1 3000 0.83 0.81 6 19 0.2 300 1.02 0.99 7 50 0.03 3000 1.14 1.12 8 50 0.1 300 1.03 1.09 9 50 0.2 1200 0.96 1.01

[0068] It can be seen from table 3 that the total wear rate of the rail and wheel is the smallest when spindle speed is 19 r/min. feed rate is 0.1 mm/r and pressure is 1200 N. In this case the horizontal combination is A.sub.2B.sub.2C.sub.2.

[0069] Analyze the Results of the Experiment

[0070] 1. Analysis of the total wear rate of sliding wear, table 4.

TABLE-US-00005 Factors Calculated Spindle speed Feed rate Pressure value (r/min) A (mm/r) B (N) C K.sub.1 3.07 3.34 3.28 K.sub.2 2.82 2.75 2.83 K.sub.3 3.22 3.02 2.96 k.sub.1 1.02 1.11 1.09 k.sub.2 0.94 0.92 0.94 k.sub.3 1.07 1.01 0.99 Range R 0.13 0.19 0.15

[0071] For the spindle speed A, it can be seen that k.sub.3>k.sub.1>k.sub.2. Since the result index is the wear rate, the minimum value of the wear rate is expected, so it can be judged that A.sub.2 is the excellent level of factor A.

[0072] In the same way, the excellent levels of factor B and factor C are B.sub.2 and C.sub.2 respectively. So the optimal combination is A.sub.2B.sub.2C.sub.2. In addition, it can be seen from the value of the range R that factor B has the greatest influence on the sliding wear rate among the three experimental factors.

[0073] 2. Analysis of the total wear rate of rolling wear, table 5.

TABLE-US-00006 Factors Calculated Spindle speed Feed rate value (r/min) A (mm/r) B Pressure (N) C K.sub.1 3.05 3.41 3.28 K.sub.2 2.89 2.69 2.88 K.sub.3 3.03 2.97 2.95 k.sub.1 1.02 1.12 1.09 k.sub.2 0.96 0.90 0.96 k.sub.3 1.01 0.99 0.98 Range R 0.06 0.22 0.13

[0074] For the spindle speed A, it can be seen that k.sub.3>k.sub.1>k.sub.2. Since the result index is the wear rate, the minimum value of the wear rate is expected, so it can be judged that A.sub.2 is the excellent level of factor A.

[0075] In the same way, the excellent levels of factor B and factor C are B.sub.2 and C.sub.2 respectively. So the optimal combination is A.sub.2B.sub.2C.sub.2. In addition, it can be seen from the value of the range R that factor B has the greatest influence on the rolling wear rate among the three experimental factors.

[0076] According to the analysis results of sliding wear rate and the results of rolling wear rate, the optimal combination is A.sub.2B.sub.2C.sub.2, therefore, the workpiece processed by A.sub.2B.sub.2C.sub.2 corresponding parameters was selected for the friction and wear test. The test results show that after surface treatment, the wear resistance of wheels sample in both the rolling wear and sliding wear test are improved by more than 50%. At the same time, the wear rate of rail specimens after surface treatment with wheel specimens is also significantly reduced.