Ultrasonic detection method for rolled and forged high-manganese alloy steel rail

Abstract

The invention relates to the technical field of ultrasonic detection of steel rails, in particular to an ultrasonic detection method for rolled and forged high-manganese alloy steel rails, which comprises the following steps: preparing two sections of rolled and forged high-manganese alloy steel rails, and respectively marking the two sections of rolled and forged high-manganese alloy steel rails as a first test block and a second test block; processing a plurality of flat-bottom holes with different depths in corresponding positions of the first test block and the second test block; selecting a probe for ultrasonic detection; performing time base calibration and sensitivity setting on the selected probe; the probe is used for scanning the position, represented by sensitivity setting, of the rolled and forged high-manganese alloy steel rail to be detected so as to obtain a detection result; and carrying out transmission correction on the detected defects exceeding the scanning sensitivity according to a comparison method, and then evaluating whether the defects are qualified or not. The ultrasonic detection method is used for detecting the internal defects of the rolled and forged high-manganese alloy steel rail, and the problem that no nondestructive detection means is used for effectively controlling the internal quality of the rolled and forged high-manganese alloy steel rail at present is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic testing of steel rails, and particularly to an ultrasonic testing method for rolled and forged high manganese alloy steel rails. Background Art

[0002] Rolled and forged alloy steel rails are a special type of frog processing material that combines new materials (referring to a relatively high manganese content) and new processes (referring to the rolling and forging process, while existing manganese alloy steels usually adopt the casting process). Currently, there is no precedent for using non-destructive testing methods for internal quality control at home and abroad. Therefore, there is an urgent need to provide a new solution. Summary of the Invention

[0003] The purpose of the present invention is to overcome the defects of the prior art and provide an ultrasonic testing method for rolled and forged high manganese alloy steel rails, so as to solve the problem that there is no non-destructive testing method for quality control of rolled and forged alloy steel rails in the prior art.

[0004] The technical solution for achieving the above purpose is as follows:

[0005] The present invention provides an ultrasonic testing method for rolled and forged high manganese alloy steel rails, including the following steps:

[0006] Prepare two sections of rolled and forged high manganese alloy steel rails, which are respectively marked as the first test block and the second test block;

[0007] Process a plurality of flat-bottomed holes with different depths at corresponding positions on the first test block and the second test block;

[0008] Select a probe for ultrasonic testing;

[0009] Perform time-base calibration and set the evaluation sensitivity for the ultrasonic testing system of the selected probe;

[0010] Use the probe to scan the detection surface represented by the set evaluation sensitivity of the rolled and forged high manganese alloy steel rail to be detected to obtain the detection result;

[0011] Evaluate the detection results that exceed the set scanning sensitivity after transmission correction using the comparison method.

[0012] The further improvement of the ultrasonic testing method for rolled and forged high manganese alloy steel rails of the present invention lies in that processing a plurality of flat-bottomed holes with different depths at corresponding positions on the first test block and the second test block includes the following steps:

[0013] Process 10 T-type flat-bottomed holes on the side surface of the rail head of the first test block, marked as T1 to T10, and the depths of the 10 processed T-type flat-bottomed holes are different;

[0014] Five Y-type flat-bottom holes are machined on the web side surface of the first test block, marked as Y1 to Y5, and the depths of the five machined Y-type flat-bottom holes are different;

[0015] Three Da-type flat-bottom holes are machined on the bottom surface of the rail of the first test block, marked as D1 to D3. The axes of the three machined Da-type flat-bottom holes are perpendicular to the corresponding upper surface of the rail bottom on the first test block, and the depths of the three machined Da-type flat-bottom holes are different;

[0016] Twelve Db-type flat-bottom holes are machined on the bottom surface of the rail of the second test block, marked as D4 to D15. The axes of the twelve machined Db-type flat-bottom holes are perpendicular to the tread surface of the rail head, and the depths of the twelve machined Db-type flat-bottom holes are different.

[0017] A further improvement of the ultrasonic testing method for rolled and forged high manganese alloy steel rails of the present invention lies in that the steps for selecting the probe for ultrasonic testing include:

[0018] Select single crystal straight probes and dual crystal straight probes with a probe frequency range of 2 MHz to 3 MHz and a wafer size of 10 mm to 30 mm.

[0019] A further improvement of the ultrasonic testing method for rolled and forged high manganese alloy steel rails of the present invention lies in that the steps for time base calibration and sensitivity setting of the ultrasonic testing system of the selected probe include:

[0020] Place the single crystal straight probe on the rail head side surface of the first test block opposite to the rail head side surface where the T-type flat-bottom hole is machined. Move and scan the single crystal straight probe at the position corresponding to the T-type flat-bottom hole T3 to find the maximum reflected echo of the T-type flat-bottom hole T3 and calibrate the zero point according to the actual depth of the T-type flat-bottom hole T3; Move and scan the single crystal straight probe at the position corresponding to the T-type flat-bottom hole T10 to find the maximum reflected echo of the T-type flat-bottom hole T10 and calibrate the sound velocity according to the actual depth of the T-type flat-bottom hole T10;

[0021] Use the T-type flat-bottom holes T3 to T10 on the first test block to make the first DAC curve for the single crystal straight probe to scan on the rail head side surface. When making the first DAC curve, select at least 5 points. Set the evaluation sensitivity for the single crystal straight probe to scan on the rail head side surface as the first DAC curve, and set the scanning sensitivity for the single crystal straight probe to scan on the rail head side surface as the first DAC curve - 6 dB.

[0022] A further improvement of the ultrasonic testing method for rolled and forged high manganese alloy steel rails of the present invention lies in that the steps for time base calibration and sensitivity setting of the ultrasonic testing system of the selected probe further include:

[0023] Place the single-crystal straight probe on the tread surface of the rail head of the second test block, move and scan the single-crystal straight probe at the position corresponding to the flat-bottomed hole D6 of Class Db, find the maximum reflected echo of the flat-bottomed hole D6 of Class Db and calibrate the zero point according to the actual depth of the flat-bottomed hole D6 of Class Db; move and scan the single-crystal straight probe at the position corresponding to the flat-bottomed hole D15 of Class Db, find the maximum reflected echo of the flat-bottomed hole D15 of Class Db and calibrate the sound velocity according to the actual depth of the flat-bottomed hole D15 of Class Db.

[0024] Use the flat-bottomed holes D6 - D15 of Class Db on the second test block to make the second DAC curve for the side scan of the rail web by the single-crystal straight probe. When making the second DAC curve, select at least 5 points. Set the evaluation sensitivity for the scan on the tread surface of the rail head by the single-crystal straight probe as the second DAC curve, and set the scan sensitivity for the scan on the tread surface of the rail head by the single-crystal straight probe as the second DAC curve - 6dB.

[0025] A further improvement of the ultrasonic testing method for the rolled and forged high manganese alloy steel rail of the present invention is that the time-base calibration and sensitivity setting of the ultrasonic testing system for the selected probe further include the following steps:

[0026] Place the dual-crystal straight probe on the tread surface of the rail head of the second test block, move and scan the dual-crystal straight probe at the position corresponding to the flat-bottomed hole D4 of Class Db, find the maximum reflected echo of the flat-bottomed hole D4 of Class Db and calibrate the zero point according to the actual depth of the hole; move and scan the dual-crystal straight probe at the position corresponding to the flat-bottomed hole D8 of Class Db, find the maximum reflected echo of the flat-bottomed hole D8 of Class Db and calibrate the sound velocity according to the actual depth of the flat-bottomed hole D8 of Class Db.

[0027] Use the flat-bottomed holes D4 - D8 of Class Db on the second test block to make the third DAC curve for the scan on the tread surface of the rail head by the dual-crystal straight probe. Set the evaluation sensitivity for the scan on the tread surface of the rail head by the dual-crystal straight probe as the third DAC curve, and set the scan sensitivity for the scan on the tread surface of the rail head by the dual-crystal straight probe as the third DAC curve - 6dB.

[0028] A further improvement of the ultrasonic testing method for the rolled and forged high manganese alloy steel rail of the present invention is that the time-base calibration and sensitivity setting of the ultrasonic testing system for the selected probe further include the following steps:

[0029] Place the double-crystal straight probe on the web side of the first test block opposite to the web side with flat-bottomed holes of type Y machined, move and scan the double-crystal straight probe at the position corresponding to flat-bottomed hole Y1 of type Y, find the maximum reflected echo of flat-bottomed hole Y1 of type Y and calibrate the zero point according to the actual depth of flat-bottomed hole Y1 of type Y; move and scan the double-crystal straight probe at the position corresponding to flat-bottomed hole Y5 of type Y, find the maximum reflected echo of flat-bottomed hole Y5 of type Y and calibrate the sound velocity according to the actual depth of flat-bottomed hole Y5 of type Y.

[0030] Use flat-bottomed holes Y1 - Y5 of type Y on the first test block to make the fourth DAC curve for the double-crystal straight probe to scan on the web side, set the evaluation sensitivity for the double-crystal straight probe to scan on the web side as the fourth DAC curve, and set the scanning sensitivity for the double-crystal straight probe to scan on the web side as the fourth DAC curve - 6dB.

[0031] A further improvement of the ultrasonic testing method for rolled and forged high manganese alloy steel rails of the present invention lies in that the time-base calibration and sensitivity setting of the ultrasonic testing system for the selected probe further include the following steps:

[0032] Place the double-crystal straight probe on the upper inclined surface of the rail base corresponding to the lower surface of the rail base with flat-bottomed holes of type Da machined on the first test block, move and scan the double-crystal straight probe at the position corresponding to flat-bottomed hole D1 of type Da, find the maximum reflected echo of flat-bottomed hole D1 of type Da and calibrate the zero point according to the actual depth of flat-bottomed hole D1 of type Da; move and scan the double-crystal straight probe at the position corresponding to flat-bottomed hole D3 of type Da, find the maximum reflected echo of flat-bottomed hole D3 of type Da and calibrate the sound velocity according to the actual depth of the flat-bottomed hole.

[0033] Use flat-bottomed holes D1 - D3 of type Da on the first test block to make the fifth DAC curve for the double-crystal straight probe to scan on the upper surface of the rail base, set the evaluation sensitivity for the double-crystal straight probe to scan on the upper surface of the rail base as the fifth DAC curve, and set the scanning sensitivity for the double-crystal straight probe to scan on the upper surface of the rail base as the fifth DAC curve - 6dB.

[0034] A further improvement of the ultrasonic testing method for rolled and forged high manganese alloy steel rails of the present invention lies in that when using the probe to scan the to-be-tested rolled and forged high manganese alloy steel rails on the detection surface represented by the set evaluation sensitivity, the adjacent two scans should overlap 12% of the wafer size, and control the moving speed of the probe not to be greater than 120mm / s.

[0035] A further improvement of the ultrasonic testing method for rolled and forged high manganese alloy steel rails of the present invention lies in that

[0036] The evaluation of the detection results exceeding the set sensitivity after transmission correction using the comparison method includes the following steps:

[0037] The detection results exceeding the set scanning sensitivity are corrected for transmission using the comparison method;

[0038] If the detection results corrected for transmission using the comparison method exceed the corresponding evaluation sensitivity, it is determined to be unqualified;

[0039] If the detection results corrected for transmission using the comparison method do not exceed the corresponding evaluation sensitivity, it is determined to be qualified.

[0040] The beneficial effects of the ultrasonic detection method for rolled and forged high manganese alloy steel rails of the present invention are as follows:

[0041] The present invention uses the ultrasonic detection method to detect internal defects of rolled and forged high manganese alloy steel rails, solving the problem that there is currently no non-destructive detection method for effective internal quality control. The detection method of the present invention has strong operability and can be widely applied to the ultrasonic detection of materials with acoustic anisotropy. Brief Description of the Drawings

[0042] Figure 1 It is a flow chart of an ultrasonic detection method for rolled and forged high manganese alloy steel rails of the present invention.

[0043] Figure 2 It is a longitudinal sectional view of the first test block in the ultrasonic detection method for rolled and forged high manganese alloy steel rails of the present invention.

[0044] Figure 3 It is a transverse sectional view of the first test block in the ultrasonic detection method for rolled and forged high manganese alloy steel rails of the present invention.

[0045] Figure 4 It is a longitudinal sectional view of the second test block in the ultrasonic detection method for rolled and forged high manganese alloy steel rails of the present invention.

[0046] Figure 5 It is a transverse sectional view of the second test block in the ultrasonic detection method for rolled and forged high manganese alloy steel rails of the present invention. Detailed Description of the Invention

[0047] The present invention will be further described below in conjunction with the drawings and specific embodiments.

[0048] Refer to Figure 1 , the present invention provides an ultrasonic detection method for rolled and forged high manganese alloy steel rails, which is used for quality control of alloy steel rails to solve the problem that there is currently no non-destructive detection method for effective internal quality control. The ultrasonic detection method for rolled and forged high manganese alloy steel rails of the present invention will be described below in conjunction with the drawings.

[0049] Refer to Figure 1, showing the flow chart of an ultrasonic testing method for rolled and forged high manganese alloy steel rails of the present invention. The following will be combined with Figure 1 , to describe the ultrasonic testing method for rolled and forged high manganese alloy steel rails of the present invention.

[0050] As Figure 1 shown, an ultrasonic testing method for rolled and forged high manganese alloy steel rails of the present invention includes the following steps:

[0051] Execute step S11 to prepare two sections of rolled and forged high manganese alloy steel rails, respectively marked as the first test block and the second test block; then execute step S12;

[0052] Execute step S12 to machine a plurality of flat-bottomed holes with different depths at corresponding positions on the first test block and the second test block; then execute step S13;

[0053] Execute step S13 to select a probe for ultrasonic testing; then execute step S14;

[0054] Execute step S14 to perform time-base calibration and sensitivity setting on the ultrasonic testing system of the selected probe; then execute step S15;

[0055] Execute step S15 to scan the rolled and forged high manganese alloy steel rail to be tested with the probe on the detection surface represented by the set evaluation sensitivity to obtain a detection result; then execute step S16;

[0056] Execute step S16 to evaluate the detection results that exceed the set scanning sensitivity after transmission correction using the comparison method.

[0057] Furthermore, the detection results and evaluation results are correspondingly recorded and stored.

[0058] In a specific embodiment of the present invention, the preparation process of the first test block and the second test block in step S11 is the same as the preparation process of the rolled and forged high manganese alloy steel rail to be tested.

[0059] Machining a plurality of flat-bottomed holes with different depths at corresponding positions on the first test block and the second test block includes the following steps:

[0060] As Figure 2 and Figure 3As shown, 10 flat-bottomed holes of type T are machined on the side Q of the rail head of the first test block 21, marked as T1 to T10, and the depths of the 10 machined flat-bottomed holes of type T are different; specifically, the diameter of the flat-bottomed hole of type T is φ2, and the displayed depths H1 from the bottom of the flat-bottomed holes T1 to T10 to the side P of the rail head are 10mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, and 100mm respectively. The central axes of the flat-bottomed holes T1 to T10 are perpendicular to the side Q and the side P of the rail head, and the distance from this central axis to the running surface of the rail top is 25.4mm, that is, the flat-bottomed holes T1 to T10 are provided at the center of the side Q of the rail head. The spacing between the flat-bottomed holes T1 to T6 is 40mm, the spacing between the flat-bottomed holes T6 to T10 is 50mm, the length of the first test block 21 is 500mm, and the distances from the flat-bottomed hole T1 and the flat-bottomed hole T10 to the corresponding end faces are 50mm.

[0061] 5 flat-bottomed holes of type Y are machined on the side of the rail web of the first test block 21, marked as Y1 to Y5, and the depths of the 5 machined flat-bottomed holes of type Y are different; specifically, the diameter of the flat-bottomed holes Y1 to Y5 of type Y is φ2, and they are located in the middle of the rail web in the vertical direction. The displayed depths H2 from the bottom of the flat-bottomed holes Y1 to Y5 to the side M of the rail web are 5mm, 10mm, 20mm, 30mm, and 35mm respectively. The spacing between the flat-bottomed holes Y1 to Y5 is 40mm, and the distance from the flat-bottomed hole Y1 to the corresponding end face is 50mm.

[0062] 3 flat-bottomed holes of type Da are machined on the bottom surface of the rail base of the first test block 21, marked as D1 to D3. The axes of the 3 machined flat-bottomed holes of type Da are perpendicular to the corresponding upper surface of the rail base on the first test block, and the depths of the 3 machined flat-bottomed holes of type Da are different. The diameter of the flat-bottomed holes D1 to D3 of type Da is φ2, the bottom surfaces of the flat-bottomed holes D1 to D3 are parallel to the upper surface N of the rail base, the centers of the flat-bottomed holes of type Da are directly opposite to the center of the upper surface N of the rail base, and the displayed depths H3 from the bottom of the flat-bottomed holes D1 to D3 to the upper surface N of the rail base are 5mm, 15mm, and 20mm respectively. The spacing between the flat-bottomed holes D1 to D3 is 100mm, and the distance from the flat-bottomed hole D1 to the corresponding end face is 100mm. In Figure 2 the flat-bottomed holes of type Da are indicated by dotted lines;

[0063] As Figure 4 and Figure 5As shown in the figure, 12 Db-class flat-bottom holes are machined on the bottom surface of the rail of the second test block 22, marked as D4 to D15. The axes of the 12 machined Db-class flat-bottom holes are perpendicular to the tread R of the rail head, and the depths of the 12 machined Db-class flat-bottom holes are different. Specifically, the aperture of the Db-class flat-bottom holes D4 to D15 is φ2. The central axes of the Db-class flat-bottom holes D4 to D15 are located on the center line of the bottom surface of the rail. The displayed depths H4 from the bottom of the Db-class flat-bottom holes D4 to D15 to the tread R of the rail head are 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 90 mm, 120 mm, 150 mm, 160 mm, and 170 mm respectively. The spacing between the Db-class flat-bottom holes D4 and D9 is 40 mm, the spacing between the Db-class flat-bottom holes D9 and D15 is 50 mm, the distances from the Db-class flat-bottom holes D4 and D15 to the corresponding end faces are 50 mm. The height of the second test block 22 is 180 mm, and the length of the second test block 22 is 600 mm.

[0064] In a specific embodiment of the present invention, the steps for selecting a probe for ultrasonic testing include the following:

[0065] Select a single-crystal straight probe and a double-crystal straight probe with a probe frequency range of 2 MHz to 3 MHz and a wafer size of 10 mm to 30 mm.

[0066] In a specific embodiment of the present invention, the steps for time-base calibration and sensitivity setting of the ultrasonic testing system for the selected probe include the following:

[0067] Connect the ultrasonic testing instrument and the single-crystal straight probe, set the corresponding parameters, and then scan the single-crystal straight probe on the side surface P of the rail head of the first test block 21, and use the T-class flat-bottom holes T3 and T10 to calibrate the zero point and the sound velocity: As Figure 2 shown, place the single-crystal straight probe on the side surface P of the rail head of the first test block 21 opposite to the side surface Q of the rail head where the T-class flat-bottom holes are machined. Move and scan the single-crystal straight probe at the position corresponding to the T-class flat-bottom hole T3. Specifically, it can be moved and scanned back and forth and left and right at the position of the T-class flat-bottom hole T3 to find the maximum reflected echo of the T-class flat-bottom hole T3 and calibrate the zero point according to the actual depth of the T-class flat-bottom hole T3; move and scan the single-crystal straight probe at the position corresponding to the T-class flat-bottom hole T10. Specifically, it can be moved and scanned back and forth and left and right at the position of the T-class flat-bottom hole T10 to find the maximum reflected echo of the T-class flat-bottom hole T10 and calibrate the sound velocity according to the actual depth of the T-class flat-bottom hole T10;

[0068] After completing the time-base calibration for the side scan of the rail head, a DAC curve is made and the sensitivity for the scan of the single-crystal straight probe on the side of the rail head is set. The set sensitivity includes setting the evaluation sensitivity and the scan sensitivity for the scan of the single-crystal straight probe on the side of the rail head. The made DAC curve is set as the evaluation sensitivity, and the DAC curve - 6dB (that is, moving the whole made DAC curve downward by 6 dB to achieve strict control of the quality of the rail) is set as the scan sensitivity. When making the DAC curve, avoid using flat-bottom holes that cause a trend deviation of the DAC curve due to uneven material structure. Specifically: Use the T-type flat-bottom holes T3 - T10 on the first test block to make the first DAC curve for the scan of the single-crystal straight probe on the side of the rail head. When making the first DAC curve, select at least 5 points. Set the evaluation sensitivity for the scan of the single-crystal straight probe on the side of the rail head as the first DAC curve, and set the scan sensitivity for the scan of the single-crystal straight probe on the side of the rail head as the first DAC curve - 6dB. When making the first DAC curve, first place the single-crystal straight probe on the side P of the rail head of the first test block 21, and perform forward, backward, left, and right movement scans at the position corresponding to the T-type flat-bottom hole T3. Find the maximum reflected echo of the T-type flat-bottom hole T3 and set it as the first point of the first DAC curve. Then, in turn, use the T-type flat-bottom holes T4 - T10 to complete the production of the first DAC curve for the entire side scan of the rail head according to the above method.

[0069] After completing the sensitivity setting for the side of the rail head, use the single-crystal straight probe to scan on both sides of the rail head of the to-be-detected rolled and forged high manganese alloy steel rail (both sides of the rail head need to be fully scanned). When scanning, control that the adjacent two scans should overlap 12% of the wafer size with each other, and control the moving speed of the probe not to be greater than 120 mm / s.

[0070] Perform display evaluation on the results of the scan of the side of the rail head of the to-be-detected rolled and forged high manganese alloy steel rail by the single-crystal straight probe:

[0071] Evaluate the detection results that exceed the set scan sensitivity after performing transmission correction using the comparison method.

[0072] Furthermore, during the process of scanning and detecting using the single-crystal straight probe, if a detection result that exceeds the scan sensitivity is found, measure the difference in sound energy transmission loss according to the comparison method and perform transmission correction. After correction, perform display evaluation. If it exceeds the corresponding acceptance rule, it is judged as unqualified; if it does not exceed the corresponding acceptance rule, it is judged as qualified.

[0073] Specifically, if the detection result of performing transmission correction using the comparison method exceeds the corresponding evaluation sensitivity, it is judged as unqualified;

[0074] If the detection result of performing transmission correction using the comparison method does not exceed the corresponding evaluation sensitivity, it is judged as qualified.

[0075] In a specific embodiment of the present invention, the time-base calibration and sensitivity setting of the ultrasonic detection system for the selected probe further include the following steps:

[0076] Connect the ultrasonic detection instrument and the single-crystal straight probe, set the corresponding parameters, then scan the single-crystal straight probe on the running surface R of the rail head of the second test block 22, and use the flat-bottom holes D6 of Db type and the flat-bottom holes D15 of Db type to calibrate the zero point and the sound velocity: As Figure 4 shown, place the single-crystal straight probe on the running surface R of the rail head of the second test block 22, move and scan the single-crystal straight probe at the position corresponding to the flat-bottom hole D6 of Db type. Specifically, it can be moved and scanned back and forth, left and right at the position of the flat-bottom hole D6 of Db type to find the maximum reflected echo of the flat-bottom hole D6 of Db type and calibrate the zero point according to the actual depth of the flat-bottom hole D6 of Db type; move and scan the single-crystal straight probe at the position corresponding to the flat-bottom hole D15 of Db type. Specifically, it can be moved and scanned back and forth, left and right at the position of the flat-bottom hole D15 of Db type to find the maximum reflected echo of the flat-bottom hole D15 of Db type and calibrate the sound velocity according to the actual depth of the flat-bottom hole D15 of Db type;

[0077] After completing the time-base calibration of the single-crystal straight probe scanning on the running surface of the rail head, set the sensitivity of the single-crystal straight probe. Set the DAC curve as the evaluation sensitivity, and set the DAC curve - 6dB as the scanning sensitivity. When making the DAC curve, avoid using the flat-bottom holes that cause a trend deviation of the DAC curve due to uneven material structure; specifically: use the flat-bottom holes D6 - D15 of Db type on the second test block to make the second DAC curve for the single-crystal straight probe scanning on the running surface of the rail head. When making the second DAC curve, select at least 5 points. Set the evaluation sensitivity for the single-crystal straight probe scanning on the running surface of the rail head as the second DAC curve, and set the scanning sensitivity for the single-crystal straight probe scanning on the running surface of the rail head as the second DAC curve - 6dB. When making the second DAC curve, first place the single-crystal straight probe on the running surface R of the rail head of the second test block 22, move and scan back and forth, left and right at the position corresponding to the flat-bottom hole D6 of Db type to find the maximum reflected echo of the flat-bottom hole D6 of Db type and set it as the first point of the DAC curve, and then complete the production of the second DAC curve for the single-crystal straight probe scanning on the running surface of the rail head in sequence by the above method using the flat-bottom holes D7 - D15 of Db type.

[0078] After completing the sensitivity setting of the running surface of the rail head, use the single-crystal straight probe to scan the running surface of the rail head of the to-be-detected rolled and forged high manganese alloy steel rail. During the scanning, make the adjacent two scans overlap 12% of the wafer size, and control the moving speed of the probe not to be greater than 120 mm / s.

[0079] The results of scanning the tread of the rail head of the rolled and forged high manganese alloy steel rail to be detected with a single crystal straight probe are displayed and evaluated:

[0080] The detection results exceeding the set scanning sensitivity are evaluated after transmission correction using the comparison method.

[0081] Furthermore, during the process of scanning and detecting with a single crystal straight probe, if a detection result exceeding the scanning sensitivity is found, the difference in acoustic energy transmission loss is measured according to the comparison method and transmission correction is performed. After correction, the display evaluation is carried out. If it exceeds the corresponding acceptance rule, it is judged as unqualified; if it does not exceed the corresponding acceptance rule, it is judged as qualified.

[0082] Specifically, if the detection result of transmission correction using the comparison method exceeds the corresponding evaluation sensitivity, it is judged as unqualified;

[0083] if the detection result of transmission correction using the comparison method does not exceed the corresponding evaluation sensitivity, it is judged as qualified.

[0084] In a specific embodiment of the present invention, the time base calibration and sensitivity setting of the ultrasonic detection system for the selected probe further include the following steps:

[0085] Connect the ultrasonic detection instrument and the double crystal straight probe, set the corresponding parameters, and then scan the double crystal straight probe on the tread R of the rail head of the second test block 22, and calibrate the zero point and sound velocity using the Db type flat bottom hole D4 and the Db type flat bottom hole D8: As Figure 4 shown, place the double crystal straight probe on the tread R of the second test block 22, move and scan the double crystal straight probe at the position corresponding to the Db type flat bottom hole D4. Specifically, it can be moved and scanned back and forth, left and right at the position of the Db type flat bottom hole D4 to find the maximum reflected echo of the Db type flat bottom hole D4 and calibrate the zero point according to the actual depth of the hole; move and scan the double crystal straight probe at the position corresponding to the Db type flat bottom hole D8. Specifically, it can be moved and scanned back and forth, left and right at the position of the Db type flat bottom hole D8 to find the maximum reflected echo of the Db type flat bottom hole D8 and calibrate the sound velocity according to the actual depth of the Db type flat bottom hole D8;

[0086] After completing the time-base calibration of the double-crystal straight probe during the inspection of the rail head tread, set the sensitivity of the double-crystal straight probe. Set the DAC curve as the evaluation sensitivity, and set the DAC curve - 6dB as the inspection sensitivity. When making the DAC curve, avoid using flat-bottom holes that cause a trend deviation in the DAC curve due to uneven material structure; specifically: use the Db type flat-bottom holes D4 - D8 on the second test block 22 to make the third DAC curve for the inspection of the double-crystal straight probe on the rail head tread. Set the evaluation sensitivity for the inspection of the double-crystal straight probe on the rail head tread as the third DAC curve, and set the inspection sensitivity for the inspection of the double-crystal straight probe on the rail head tread as the third DAC curve - 6dB. When making the third DAC curve, first place the double-crystal straight probe on the rail head tread of the first test block 21, and perform scanning with front-back, left-right movement at the position corresponding to the Db type flat-bottom hole D4. Find the maximum reflected echo of the Db type flat-bottom hole D4 and set it as the first point of the third DAC curve. Then, sequentially complete the production of the third DAC curve for the inspection of the double-crystal straight probe on the rail head tread using the Db type flat-bottom holes D5 - D8 according to the above method.

[0087] After completing the sensitivity setting of the double-crystal straight probe during the inspection of the rail head tread, use the double-crystal straight probe to scan the rail head tread of the to-be-inspected rolled-forged high manganese alloy steel rail. The moving direction of the double-crystal straight probe should be perpendicular to its sound insulation layer. During scanning, make the adjacent two scans overlap by 12% of the wafer size, and control the moving speed of the probe not to exceed 120 mm / s.

[0088] For the result of the double-crystal straight probe scanning the rail head tread of the to-be-inspected rolled-forged high manganese alloy steel rail, perform display and evaluation:

[0089] Evaluate the inspection results that exceed the set inspection sensitivity after performing transmission correction using the comparison method.

[0090] Furthermore, during the process of using the double-crystal straight probe for scanning and inspection, if a detection result exceeding the inspection sensitivity is found, measure the difference in sound energy transmission loss according to the comparison method and perform transmission correction. After correction, perform display and evaluation. If it exceeds the corresponding acceptance rule, it is judged as unqualified; if it does not exceed the corresponding acceptance rule, it is judged as qualified.

[0091] Specifically, if the inspection result of the transmission correction using the comparison method exceeds the corresponding evaluation sensitivity, it is judged as unqualified;

[0092] If the inspection result of the transmission correction using the comparison method does not exceed the corresponding evaluation sensitivity, it is judged as qualified.

[0093] In a specific embodiment of the present invention, the time-base calibration and sensitivity setting of the ultrasonic detection system for the selected probe further include the following steps:

[0094] Connect the ultrasonic testing instrument to the dual-crystal straight probe, set the corresponding parameters, then scan the dual-crystal straight probe on the web side M of the first test block 21, and use the type Y flat-bottom hole Y1 and the type Y flat-bottom hole Y5 to calibrate the zero point and sound velocity: As Figure 2 shown, place the dual-crystal straight probe on the web side M of the first test block 21 opposite to the web side with the type Y flat-bottom hole processed, move and scan the dual-crystal straight probe at the position corresponding to the type Y flat-bottom hole Y1. Specifically, it can be moved and scanned back and forth, left and right at the position of the type Y flat-bottom hole Y1 to find the maximum reflected echo of the type Y flat-bottom hole Y1 and calibrate the zero point according to the actual depth of the type Y flat-bottom hole Y1; move and scan the dual-crystal straight probe at the position corresponding to the type Y flat-bottom hole Y5. Specifically, it can be moved and scanned back and forth, left and right at the position of the type Y flat-bottom hole Y5 to find the maximum reflected echo of the type Y flat-bottom hole Y5 and calibrate the sound velocity according to the actual depth of the type Y flat-bottom hole Y5;

[0095] After completing the time-base calibration of the web side scan, set the evaluation sensitivity of the dual-crystal straight probe. Set the DAC curve as the evaluation sensitivity, and set the DAC curve - 6dB as the scan sensitivity. When making the DAC curve, avoid using the flat-bottom holes that cause the DAC curve to deviate trendily due to uneven material structure. Specifically: Use the type Y flat-bottom holes Y1 - Y5 on the first test block to make the fourth DAC curve for scanning on the web side of the dual-crystal straight probe. Set the evaluation sensitivity for scanning on the web side of the dual-crystal straight probe as the fourth DAC curve, and set the scan sensitivity for scanning on the web side of the dual-crystal straight probe as the fourth DAC curve - 6dB. When making the fourth DAC curve, first place the dual-crystal straight probe on the web side M of the first test block 21, move and scan back and forth, left and right at the position corresponding to the type Y flat-bottom hole Y1 to find the maximum reflected echo of the type Y flat-bottom hole Y1 and set it as the first point of the fourth DAC curve, and then complete the production of the fourth DAC curve for scanning on the web side in turn using the type Y flat-bottom holes Y2 - Y5 according to the above method.

[0096] After completing the sensitivity setting of the web side, use the dual-crystal straight probe to scan the web side of the to-be-tested rolled and forged high manganese alloy steel rail. The moving direction of the dual-crystal straight probe should be perpendicular to its sound insulation layer. During scanning, make the adjacent two scans overlap 12% of the wafer size, and control the moving speed of the probe not to be greater than 120 mm / s.

[0097] Carry out display and evaluation on the results of scanning the web side of the to-be-tested rolled and forged high manganese alloy steel rail with the dual-crystal straight probe:

[0098] Evaluate the test results that exceed the set scan sensitivity after transmission correction using the comparison method.

[0099] Furthermore, during the process of scanning and detecting with a double-crystal straight probe, if a detection result exceeding the scanning sensitivity is found, the difference in acoustic energy transmission loss is measured by the comparison method and transmission correction is performed. After correction, display evaluation is carried out. If it exceeds the corresponding acceptance rules, it is judged as unqualified; if it does not exceed the corresponding acceptance rules, it is judged as qualified.

[0100] Specifically, if the detection result of transmission correction using the comparison method exceeds the corresponding evaluation sensitivity, it is judged as unqualified;

[0101] if the detection result of transmission correction using the comparison method does not exceed the corresponding evaluation sensitivity, it is judged as qualified.

[0102] In a specific embodiment of the present invention, the time-base calibration and sensitivity setting of the ultrasonic detection system for the selected probe further include the following steps:

[0103] Connect the ultrasonic detection instrument and the double-crystal straight probe, set the corresponding parameters, and then scan the double-crystal straight probe on the upper surface N of the rail bottom of the first test block 21, and use the flat-bottom hole D1 of type Da and the flat-bottom hole D3 of type Da to calibrate the zero point and sound velocity: As Figure 2 shown, place the double-crystal straight probe on the upper surface N of the rail bottom corresponding to the lower surface of the rail with the flat-bottom hole D1 of type Da on the first test block 21, and move and scan the double-crystal straight probe at the position of the corresponding flat-bottom hole D1 of type Da. Specifically, it can be moved and scanned back and forth, left and right at the position of the flat-bottom hole D1 of type Da to find the maximum reflected echo of the flat-bottom hole D1 of type Da and calibrate the zero point according to the actual depth of the flat-bottom hole D1 of type Da; move and scan the double-crystal straight probe at the position of the corresponding flat-bottom hole D3 of type Da. Specifically, it can be moved and scanned back and forth, left and right at the position of the flat-bottom hole D3 of type Da to find the maximum reflected echo of the flat-bottom hole D3 of type Da and calibrate the sound velocity according to the actual depth of the flat-bottom hole of type Da;

[0104] After completing the time-base calibration for the upper surface scan of the rail bottom, set the sensitivity of the double-crystal straight probe. Set the DAC curve as the evaluation sensitivity, and set the DAC curve - 6dB as the scan sensitivity. When making the DAC curve, avoid using flat-bottom holes that cause a trend deviation in the DAC curve due to uneven material structure; specifically: use the flat-bottom holes D1 to D3 of type Da on the first test block to make the fifth DAC curve for the double-crystal straight probe to scan on the upper surface of the rail bottom. Set the evaluation sensitivity for the double-crystal straight probe to scan on the upper surface of the rail bottom as the fifth DAC curve, and set the scan sensitivity for the double-crystal straight probe to scan on the upper surface of the rail bottom as the fifth DAC curve - 6dB. When making the fifth DAC curve, first place the double-crystal straight probe on the upper surface N of the rail bottom of the first test block 21, perform a forward-backward and left-right movement scan at the position corresponding to the flat-bottom hole D1 of type Da, find the maximum echo of the flat-bottom hole D1 of type Da and set it as the first point of the fifth DAC curve. Then, in turn, use the flat-bottom holes D2 to D3 to complete the production of the fifth DAC curve for the upper surface scan of the rail bottom according to the above method.

[0105] After completing the sensitivity setting for the upper surface of the rail bottom, use the double-crystal straight probe to scan the upper surfaces N and S of the rail bottom of the to-be-detected rolled and forged high-manganese alloy steel rail. The moving direction of the double-crystal straight probe should be perpendicular to its sound insulation layer. During the scan, make the adjacent two scans overlap by 12% of the wafer size, and control the moving speed of the probe not to exceed 120 mm / s.

[0106] For the results of the double-crystal straight probe scanning the upper surface of the to-be-detected rolled and forged high-manganese alloy steel rail, perform a display evaluation:

[0107] Evaluate the detection results that exceed the set scan sensitivity after performing transmission correction using the comparison method.

[0108] Furthermore, during the process of scanning and detecting using the double-crystal straight probe, if a detection result exceeding the scan sensitivity is found, measure the difference in sound energy transmission loss by the comparison method and perform transmission correction. After correction, perform a display evaluation. If it exceeds the corresponding acceptance rules, it is judged as unqualified; if it does not exceed the corresponding acceptance rules, it is judged as qualified.

[0109] Specifically, if the detection result of performing transmission correction using the comparison method exceeds the corresponding evaluation sensitivity, it is judged as unqualified;

[0110] If the detection result of performing transmission correction using the comparison method does not exceed the corresponding evaluation sensitivity, it is judged as qualified.

[0111] The present invention has been described in detail with reference to the embodiments accompanied by drawings. Those of ordinary skill in the art can make various variations of the present invention based on the above description. Therefore, certain details in the embodiments should not constitute a limitation to the present invention, and the protection scope of the present invention will be defined by the scope defined in the appended claims.

Claims

1. An ultrasonic detection method for rolled and forged high manganese alloy steel rails, characterized in that: The steps include: Two sections of rolled and forged high manganese alloy steel rails are prepared and marked as a first test block and a second test block respectively; Processing a plurality of flat-bottom holes of different depths at corresponding positions of the first test block and the second test block; Select the probe for ultrasonic testing; Perform time base calibration and sensitivity setting for the ultrasonic detection system of the selected probe; The probe is used to scan the detection surface represented by the sensitivity setting of the rolled and forged high manganese alloy steel rail to be detected to obtain the detection result; Detection results that exceed the set sensitivity are evaluated after transmission correction using the comparison method.

2. The ultrasonic testing method for rolled and forged high manganese alloy steel rail according to claim 1, characterized in that: Machining a plurality of flat-bottom holes of different depths at corresponding positions of the first test block and the second test block comprises the following steps: 10 T-type flat-bottom holes are machined on the side surface of the rail head of the first test block, marked as T1 to T10, and the depths of the machined 10 T-type flat-bottom holes are different; Five Y-type flat-bottom holes are machined on the side surface of the rail waist of the first test block, marked as Y1 to Y5, and the depths of the five Y-type flat-bottom holes are different; Three Da-type flat-bottom holes are processed on the lower surface of the rail bottom of the first test block, marked as D1 to D3, the axes of the processed three Da-type flat-bottom holes are perpendicular to the corresponding upper surface of the rail bottom of the first test block, and the depths of the processed three Da-type flat-bottom holes are different; Twelve Db-type flat-bottom holes are machined on the lower surface of the rail bottom of the second test block, marked as D4 to D15, the axes of the machined 12 Db-type flat-bottom holes are perpendicular to the rail head tread, and the depths of the machined 12 Db-type flat-bottom holes are different.

3. The ultrasonic testing method for rolled and forged high manganese alloy steel rail according to claim 2, characterized in that: Selecting a probe for ultrasonic testing involves the following steps: Select single crystal straight probe and double crystal straight probe with probe frequency range of 2MHz~3MHz and chip size of 10mm~30mm.

4. The ultrasonic testing method for rolled and forged high manganese alloy steel rail according to claim 3, characterized in that: The time base calibration and sensitivity setting of the ultrasonic detection system of the selected probe includes the following steps: The single crystal straight probe is placed on the side of the rail head opposite to the side of the rail head processed with the T-type flat-bottom hole on the first test block, and the single crystal straight probe is moved and scanned at the position corresponding to the T-type flat-bottom hole T3 to find the maximum reflection echo of the T-type flat-bottom hole T3 and calibrate the zero point according to the actual depth of the T-type flat-bottom hole T3; the single crystal straight probe is then moved and scanned at the position corresponding to the T-type flat-bottom hole T10 to find the maximum reflection echo of the T-type flat-bottom hole T10 and calibrate the sound velocity according to the actual depth of the T-type flat-bottom hole T10; The first DAC curve for scanning the side of the rail head with a single crystal straight probe is prepared using the T-type flat-bottom holes T3 to T10 on the first test block. At least five points are selected when preparing the first DAC curve. The evaluation sensitivity of the single crystal straight probe for scanning the side of the rail head is set to the first DAC curve. The scanning sensitivity of the single crystal straight probe for scanning the side of the rail head is set to -6dB of the first DAC curve.

5. The ultrasonic testing method for rolled and forged high manganese alloy steel rail according to claim 3, characterized in that: The time base calibration and sensitivity setting of the ultrasonic detection system of the selected probe also includes the following steps: The single crystal straight probe is placed on the rail head tread of the second test block, and the single crystal straight probe is moved and scanned at a position corresponding to the Db-type flat-bottom hole D6 to find the maximum reflection echo of the Db-type flat-bottom hole D6 and calibrate the zero point according to the actual depth of the Db-type flat-bottom hole D6; the single crystal straight probe is then moved and scanned at a position corresponding to the Db-type flat-bottom hole D15 to find the maximum reflection echo of the Db-type flat-bottom hole D15 and calibrate the sound velocity according to the actual depth of the Db-type flat-bottom hole D15; The Db-type flat-bottom holes D6 to D15 on the second test block are used to make a second DAC curve for scanning the rail head tread with a single crystal straight probe. At least 5 points are selected when making the second DAC curve, and the evaluation sensitivity of the single crystal straight probe for scanning the rail head tread is set to the second DAC curve, and the scanning sensitivity of the single crystal straight probe for scanning the rail head tread is set to -6dB of the second DAC curve.

6. The ultrasonic testing method for rolled and forged high manganese alloy steel rail according to claim 3, characterized in that: The time base calibration and sensitivity setting of the ultrasonic detection system of the selected probe also includes the following steps: The dual crystal straight probe is placed on the rail head tread of the second test block, and the dual crystal straight probe is moved and scanned at a position corresponding to the Db-type flat-bottom hole D4 to find the maximum reflection echo of the Db-type flat-bottom hole D4 and calibrate the zero point according to the actual depth of the hole; the dual crystal straight probe is then moved and scanned at a position corresponding to the Db-type flat-bottom hole D8 to find the maximum reflection echo of the Db-type flat-bottom hole D8 and calibrate the sound velocity according to the actual depth of the Db-type flat-bottom hole D8; The Db-type flat-bottom holes D4 to D8 on the second test block are used to make the third DAC curve for scanning the rail head tread with the twin crystal straight probe, the evaluation sensitivity for scanning the rail head tread with the twin crystal straight probe is set to the third DAC curve, and the scanning sensitivity for scanning the rail head tread with the twin crystal straight probe is set to -6dB of the third DAC curve.

7. The ultrasonic testing method for rolled and forged high manganese alloy steel rail according to claim 3, characterized in that: The time base calibration and sensitivity setting of the ultrasonic detection system of the selected probe also includes the following steps: The dual crystal straight probe is placed on the side of the rail waist opposite to the side of the rail waist processed with the Y-type flat-bottom hole on the first test block, and the dual crystal straight probe is moved and scanned at the position corresponding to the Y-type flat-bottom hole Y1 to find the maximum reflection echo of the Y-type flat-bottom hole Y1 and calibrate the zero point according to the actual depth of the Y-type flat-bottom hole Y1; the dual crystal straight probe is then moved and scanned at the position corresponding to the Y-type flat-bottom hole Y5 to find the maximum reflection echo of the Y-type flat-bottom hole Y5 and calibrate the sound velocity according to the preset depth of the Y-type flat-bottom hole Y5; The fourth DAC curve for scanning the side of the rail waist with the dual crystal straight probe is made by using the Y-type flat-bottom holes Y1 to Y5 on the first test block, the evaluation sensitivity of the dual crystal straight probe for scanning the side of the rail waist is set to the fourth DAC curve, and the scanning sensitivity of the dual crystal straight probe for scanning the side of the rail waist is set to -6dB of the fourth DAC curve.

8. The ultrasonic testing method for rolled and forged high manganese alloy steel rails according to claim 3, characterized in that: The time base calibration and sensitivity setting of the ultrasonic detection system of the selected probe also includes the following steps: The dual crystal straight probe is placed on the upper surface of the rail bottom of the first test block corresponding to the lower surface of the rail bottom processed with the Da-class flat-bottom hole, and the dual crystal straight probe is moved and scanned at the position of the corresponding Da-class flat-bottom hole D1 to find the maximum reflection echo of the Da-class flat-bottom hole D1 and calibrate the zero point according to the actual depth of the Da-class flat-bottom hole D1; the dual crystal straight probe is then moved and scanned at the position of the corresponding Da-class flat-bottom hole D3 to find the maximum reflection echo of the Da-class flat-bottom hole D3 and calibrate the sound velocity according to the actual depth of the Da-class flat-bottom hole; The fifth DAC curve of the dual crystal straight probe scanning on the upper surface of the rail bottom is made by using the Da type flat-bottom holes D1~D3 on the first test block, the evaluation sensitivity of the dual crystal straight probe scanning on the upper surface of the rail bottom is set to the fifth DAC curve, and the scanning sensitivity of the dual crystal straight probe scanning on the upper surface of the rail bottom is set to -6dB of the fifth DAC curve.

9. The ultrasonic testing method for rolled and forged high manganese alloy steel rail according to claim 1, characterized in that: When the probe is used to scan the inspection surface represented by the sensitivity setting for the rolled and forged high manganese alloy steel rail to be inspected, two adjacent scans should overlap each other by 12% of the chip size, and the moving speed of the probe should be controlled to be no more than 120 mm / s.

10. The ultrasonic testing method for rolled and forged high manganese alloy steel rail according to claim 1, characterized in that: The evaluation of the detection results exceeding the set scanning sensitivity after transmission correction using the comparison method includes the following steps: For detection results exceeding the set scanning sensitivity, the comparison method is used to perform transmission correction; If the test result of transmission correction using the comparison method exceeds the corresponding evaluation sensitivity, it is judged as unqualified; If the test result of transmission correction using the comparison method does not exceed the corresponding evaluation sensitivity, it is judged to be qualified.

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