Depth detection and repair method for R-angle arc crack of oil film bearing supporting roller

Abstract

The invention discloses an oil film bearing supporting roll R-angle arc crack depth detection and repair method, and belongs to the field of roll flaw detection and repair, and the method comprises the following steps: placing a K1 angle probe on the surface of a calibration block; sound velocity and reference sensitivity are set for the K1 angle probe; gridding detection is carried out on the roller body of the oil film bearing supporting roller; adjusting the position of the K1 angle probe to determine the circumferential crack depth and the maximum value; and repairing by adopting a V-shaped groove surfacing method according to the maximum value of the crack depth. The method can accurately determine the crack depth and the slotting size, saves the repair cost, maximizes the use value of the roller, and improves the production rate of a steel production line.

Description

Technical Field

[0001] The invention relates to the field of roller flaw detection and repair, in particular to a method for detecting and repairing the depth of an R-angle arc crack of an oil film bearing support roller. Background Art

[0002] In the production process of wide and thick plate rolling lines, oil film bearings are used for support rollers. This type of bearing plays an important role in the wide and thick plate rolling process due to its good load-bearing capacity and lubrication performance. However, the support roller faces relatively special working conditions during actual operation. Its rolling cycle on the machine is quite long, about 30-45 days, which means that the roller is always in a high-intensity working state for a long time. During the rolling process, the R-angle arc position of the roller neck is directly eroded by cooling water for a long time. While the cooling water plays a cooling role, it also continuously scours and chemically acts on this key part. Under long-term erosion, circumferential cracks frequently appear on the roller during use, and the extension direction of these cracks is basically perpendicular to the roller neck surface. Once such cracks appear, the roller cannot be used normally on the machine, which not only seriously affects the production efficiency of the rolling line, but also increases the cost of equipment replacement and maintenance.

[0003] At present, the existence of circumferential cracks can be determined by penetration testing at the R-angle arc position of the support roller. However, this detection method has obvious limitations, and it cannot accurately determine the depth of the crack. The depth of the crack is crucial for subsequent repair work. The unknown depth makes it difficult to formulate a repair plan, which greatly increases the difficulty of repair. In addition, although the conventional roll neck overall surfacing repair method can repair cracks to a certain extent, this method will lead to a significant increase in repair costs. It not only consumes a large amount of welding materials, but also requires more manpower and time costs for processing and testing after the repair, which is extremely unfavorable for the company's production cost control. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for detecting and repairing the depth of the R-angle arc crack of an oil film bearing support roller, aiming to solve the problem that it is difficult to judge the crack depth of the existing support roller and the conventional repair cost is high.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for detecting and repairing the depth of the R-angle arc crack of the support roller of an oil film bearing, and the specific steps are as follows:

[0006] Step 1: Place the K1 angle probe on the surface of the calibration block;

[0007] Step 2: Set the sound velocity and reference sensitivity for the K1 angle probe;

[0008] Step 3: Perform grid inspection on the roller body of the oil film bearing support roller;

[0009] Step 4: Adjust the position of the K1 oblique probe to determine the circumferential crack depth and maximum value;

[0010] Step 5: Repair by using V-groove surfacing method according to the maximum crack depth.

[0011] A further improvement of the technical solution of the present invention is that the calibration block in step 1 is a national standard test block of CSK-1A.

[0012] A further improvement of the technical solution of the present invention is that in step 2, the sound velocity is set to 3250mm / s, the benchmark sensitivity setting method is to set the benchmark sound path to 100mm, place it on the surface of the calibration block for axial pulling, and adjust the highest reflected echo wave height to full screen as the benchmark sensitivity.

[0013] The further improvement of the technical solution of the present invention lies in: the specific steps of step 3 are: setting the sound path according to the size requirements of the support roller drawing, the sound path shall not be lower than the height difference between the roller body and the R-angle arc position, after setting the sound path, the circumferential direction of the oil film bearing support roller body is gridded into 12 grid areas according to an average of 30°, the roller head roller number position is set as 12 o'clock directly above, and the corresponding grid points are detected according to the circumferential crack range displayed by the penetration test.

[0014] The further improvement of the technical solution of the present invention is that the specific steps of step 4 are:

[0015] Step 4.1: Place the K1 oblique probe on the side of the oil film bearing support roller and pull it axially in the range of 0-500mm;

[0016] Step 4.2: Adjust the height of the abnormal wave that appears within the range of 0-500mm from the end surface of the roller body to full screen, and pull the probe axially to make the abnormal wave move to half of the full screen height;

[0017] Step 4.3: The value obtained by the flaw detector gate at this time is the vertical distance from the center of the probe to the crack. The height difference from the roller body to the R corner arc position is subtracted from this value to get the crack depth value;

[0018] Step 4.4: According to the grid area division of the roller body, repeat the detection of steps 4.1 to 4.3 for each grid area to detect the maximum value of the crack depth of the oil film bearing support roller.

[0019] The further improvement of the technical solution of the present invention is that the specific steps of step 5 are as follows:

[0020] Step 5.1: according to the range of the circumferential crack, the R-angle arc position of the oil film bearing support roller is grooved at a value not less than the maximum value of the crack depth of the oil film bearing support roller detected;

[0021] Step 5.2: Make a V-groove;

[0022] Step 5.3: Repair the V-groove by surfacing welding.

[0023] A further improvement of the technical solution of the present invention is that the chip size of the K1 oblique probe is 20×22 mm.

[0024] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is: by adjusting the reference sensitivity and meshing the roller body, the crack depth can be accurately measured in conjunction with the axial measurement, and the maximum depth of the annular crack can be obtained at the same time. With the maximum depth combined with the V-groove surfacing method, the crack removal can be ensured, and frequent penetration testing can be avoided during the grooving process, thereby maximizing the use value of the roller, reducing the repair cost, and improving the production efficiency of the steel production line. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 This is a schematic diagram of the K1 oblique probe detection of the present invention;

[0027] Figure 2 This is a schematic diagram of the gridded detection of the roller body of the present invention;

[0028] Figure 3 It is a schematic diagram of the V-shaped groove of the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with embodiments:

[0030] Step 1: Place the K1 oblique probe (chip size 20×22mm) on the surface of the calibration block for axial pulling; the calibration block is the national standard test block of CSK-1A, that is, the defect position in the calibration block is 100mm;

[0031] Step 2: Set the sound velocity and reference sensitivity for the K1 oblique probe; the sound velocity is set to 3250 mm / s, the sound path is set to 100 mm according to the defect position in the calibration block, and the highest reflected echo wave height is adjusted to full screen as the reference sensitivity.

[0032] Step 3: If Figure 2As shown in the figure, grid inspection is carried out on the roller body of the oil film bearing support roller; the sound path is set according to the size requirements of the support roller drawing, and the sound path must not be lower than the height difference between the roller body and the R corner arc position, which is usually set to 500mm. After setting the sound path, the circumferential direction of the roller body of the oil film bearing support roller is gridded into 12 grid areas at an average of 30°, and the roller head roller number position is set as 12 o'clock directly above. The corresponding grid points are inspected according to the circumferential crack range displayed by the penetration test.

[0033] Step 4: Adjust the position of the K1 oblique probe to determine the circumferential crack depth and maximum value;

[0034] Step 4.1: Figure 1 As shown, the K1 oblique probe is placed on the side of the oil film bearing support roller for axial pulling, with a range of 0-500mm;

[0035] Step 4.2: Adjust the height of the abnormal wave that appears within the range of 0-500mm from the end surface of the roller body to full screen, and pull the probe axially to make the abnormal wave move to half of the full screen height;

[0036] Step 4.3: The value obtained by the flaw detector gate at this time is the vertical distance from the center of the probe to the crack. The height difference from the roller body to the R corner arc position is subtracted from this value to get the crack depth value;

[0037] Step 4.4: According to the grid area division of the roller body, repeat the detection of steps 4.1 to 4.3 for each grid area to detect the maximum value of the crack depth of the oil film bearing support roller.

[0038] Step 5: Figure 3 As shown, the V-groove surfacing method is used for repair according to the maximum crack depth.

[0039] Step 5.1: according to the range of the circumferential crack, the R-angle arc position of the oil film bearing support roller is grooved at a value not less than the maximum value of the crack depth of the oil film bearing support roller detected;

[0040] Step 5.2: Make a V-groove treatment; because the circumferential cracks of the R-angle arc of the support roller may expand at a certain angle, the V-groove treatment can completely remove the internal cracks.

[0041] Step 5.3: Repair the V-groove by surfacing welding.

[0042] Example 1: K1 oblique probe detection is performed on the depth of the circumferential crack of the R-angle arc of the oil film bearing support roller of the wide and thick plate rolling line. The probe is placed on the side of the roller (the sound velocity and the reference sensitivity are completed on the calibration block, the sound velocity is set to 3250mm / s, the sound path is set to 100mm according to the defect position of the calibration block, and the defect reflection wave is adjusted to full screen for the reference sensitivity of 76dB). According to the size requirements of the support roller drawing, the height difference between the roller body and the R-angle arc position is 245mm, so the detection sound path is set to 500mm, and then the probe is pulled axially to move the abnormal wave to half of the full screen wave height. At this time, the reading taken by the flaw detector is 275mm, minus the height difference of 245mm, which is 30mm, that is, the crack depth value of the R-angle arc position. The roller body is gridded according to the circumferential crack area for detection. The detection results show that the circumferential cracks in the 5 o'clock to 7 o'clock area of ​​the roller body are deeper, and the maximum depth is 70mm at 6 o'clock.

[0043] Later, we opened a V-groove for the R-angle arc position of the roller and performed penetration testing on the groove every 10 mm until there was no crack in the groove. The final result showed that the vertical distance from the bottom of the V-groove to the roller neck surface before surfacing was 72 mm, and no cracks were found in the groove during penetration testing, indicating that the crack depth calibration method is accurate and effective.

[0044] The oil film bearing support roller is affected by the long machine cycle, and the cracks at the R angle arc position are irreversible and cannot be eliminated during use. However, through the above detection and repair methods, the crack depth and groove size can be accurately determined, the repair cost can be saved, the use value of the roller can be maximized, and the productivity of the steel production line can be improved.

[0045] The embodiments described above are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for detecting and repairing the depth of the R-angle arc crack of an oil film bearing support roller, characterized in that: The specific steps are as follows: Step 1: Place the K1 angle probe on the surface of the calibration block; Step 2: Set the sound velocity and reference sensitivity for the K1 angle probe; Step 3: Perform grid inspection on the roller body of the oil film bearing support roller; Step 4: Adjust the position of the K1 oblique probe to determine the circumferential crack depth and maximum value; Step 5: Repair by using V-groove surfacing method according to the maximum crack depth.

2. A method for detecting and repairing the depth of R-angle arc cracks in an oil film bearing support roller according to claim 1, characterized in that: The calibration block in step 1 is the national standard test block of CSK-1A.

3. The method for detecting and repairing the depth of the R-angle arc crack of the oil film bearing support roller according to claim 2, characterized in that: In step 2, the sound velocity is set to 3250mm / s. The benchmark sensitivity is set by setting the benchmark sound path to 100mm, placing it on the surface of the calibration block for axial pulling, and adjusting the highest reflected echo wave height to full screen as the benchmark sensitivity.

4. The method for detecting and repairing the depth of the R-angle arc crack of the oil film bearing support roller according to claim 1, characterized in that: The specific steps of step 3 are as follows: set the sound path according to the size requirements of the support roller drawing. The sound path must not be lower than the height difference between the roller body and the R-angle arc position. After setting the sound path, grid the circumferential direction of the oil film bearing support roller body into 12 grid areas at an average of 30°. The roller head and roller number position is set as 12 o'clock directly above. According to the circumferential crack range displayed by the penetration test, the corresponding grid points are tested.

5. The method for detecting and repairing the depth of the R-angle arc crack of the oil film bearing support roller according to claim 1, characterized in that: Step 4 The specific steps are: Step 4.1: Place the K1 oblique probe on the side of the oil film bearing support roller and pull it axially in the range of 0-500mm; Step 4.2: Adjust the height of the abnormal wave that appears within the range of 0-500mm from the end surface of the roller body to full screen, and pull the probe axially to make the abnormal wave move to half of the full screen height; Step 4.3: The value obtained by the flaw detector gate at this time is the vertical distance from the center of the probe to the crack. The height difference from the roller body to the R corner arc position is subtracted from this value to get the crack depth value; Step 4.4: According to the grid area division of the roller body, repeat the detection of steps 4.1 to 4.3 for each grid area to detect the maximum value of the crack depth of the oil film bearing support roller.

6. The method for detecting and repairing the depth of the R-angle arc crack of the support roller of an oil film bearing according to claim 1, characterized in that: Step 5 The specific steps are as follows: Step 5.1: according to the range of the circumferential crack, the R-angle arc position of the oil film bearing support roller is grooved at a value not less than the maximum value of the crack depth of the oil film bearing support roller detected; Step 5.2: Make a V-groove; Step 5.3: Repair the V-groove by surfacing welding.

7. A method for detecting and repairing the depth of R-angle arc cracks in an oil film bearing support roller according to any one of claims 1 to 6, characterized in that: The K1 oblique probe chip size is 20×22mm.

Images