Correction method for abrasion of arc probe

Abstract

The invention belongs to the technical field of ultrasonic nondestructive testing of steel pipes, and relates to a method for correcting abrasion of an arc probe, which comprises the following steps: S1, grinding the arc of the abraded arc probe into a plane; s2, testing an incidence point of the ground plane probe by using a CSK-1A test block, and marking the position of the incidence point on the side surface of the probe; testing a K value by using the comparison sample tube; s3, pasting an organic glass sheet on the ground surface of the probe; s4, grinding the bonded probe into an arc probe matched with the outer diameter of the detected steel pipe; and S5, testing an incidence point and a K value of the arc probe. According to the method, waste caused by the fact that the K value of the arc probe does not meet the requirement can be eradicated by researching the arc probe abrasion correction method and the arc probe incidence point and K value measurement method, the effectiveness of the flaw detection result can be ensured by measuring the incidence point and K value of the arc probe in real time, and the quality of the detected steel pipe is further ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of ultrasonic nondestructive testing of steel pipes, in particular to a method for correcting the wear of an arc probe. Background Art

[0002] The existing portable shear wave contact method for flaw detection usually selects a suitable probe according to the specifications of the steel pipe, and grinds the probe into an arc shape that matches the curvature of the steel pipe. This not only causes waste (one probe corresponds to one specification), but also through the comparison of some probes that have been used for a long time with new probes, it is found that the probes that have been used for a long time are difficult to detect inner wall defects. How to ensure product quality while avoiding the waste of probes is the technical problem to be solved by the present invention. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for correcting the wear of an arc probe, which can repair and correct the worn arc probe, and the corrected probe has the same accuracy as a new probe.

[0004] The technical solution adopted by the present invention to solve the technical problem is:

[0005] The present invention provides a method for correcting arc probe wear, the steps of which are as follows:

[0006] S1 Grinding: Grind the arc of the worn arc probe into a flat surface;

[0007] S2 test: Use CSK-1A test block to test the incident point of the ground plane probe, and mark the position of the incident point on the side of the probe; use the comparison sample tube to test the K value;

[0008] S3 adhesive sheet: stick a plexiglass sheet on the polished probe surface;

[0009] S4 Arc Grinding: Grind the probe after bonding into an arc probe that matches the outer diameter of the steel pipe being probed;

[0010] S5 test: Test the arc probe incident point and K value.

[0011] Furthermore, the specific method of S4 is: when grinding, first fix a piece of coarse sandpaper close to the surface of the inspected pipe. During the grinding process, use the incident main sound beam line marked on the side of the probe as a reference, and try to keep the incident main sound beam line incident from the highest point of the arc surface of the inspected pipe to enter the pipe. When the surface of the organic glass sheet is basically consistent with the arc surface of the pipe, replace it with a piece of water-abrasive fine sandpaper on the surface of the inspected pipe, dip the probe in water and place it on the fine sandpaper for fine grinding until the arc surface of the organic glass is completely consistent with the arc surface of the pipe, the surface of the organic glass block is smooth and bright, and the incident main sound beam line basically enters the surface of the pipe from the highest point on the surface of the pipe.

[0012] Furthermore, the test method for the incident point of the arc probe described in S5 is: place the arc surface of the arc probe on the corner of the Dutch test block, move the probe back and forth so that the corner echo reaches the highest peak, and the point on the probe corresponding to the corner is the actual incident point of the arc probe, and mark the incident point on one side of the probe with a pen.

[0013] Further, the measurement method of the arc probe K value described in S5 is: take a sample tube with artificial trauma, place the probe on the outer surface of the tube, move the probe back and forth to find the maximum reflected wave of the artificial trauma, set the tube marked with the incident point as point A, set the artificial defect point as point B, set point D as the midpoint of line segment AB, OA=OB=R, and the triangle ODA is a right triangle, the line segment OA is the line connecting the tube center point O and point A, the line segment OB is the line connecting the tube center point O and point B, the line segment AB is the line connecting point A and point B, the line segment OD is the line connecting the tube center point O and point D, and point C is the intersection of the line segment OD and the inner wall of the tube; θ is the angle between the line segment OA and the line segment OD, β is the angle between the line segment OA and the line segment AC, γ is the angle between the line segment AC and the line segment OC, r is the inner diameter of the steel pipe, R is the outer diameter of the steel pipe, and the line segment length l of AB,

[0014] The actual K value of the arc probe is equal to tanβ, which is calculated by the following formula:

[0015]

[0016] Further, after step S5, according to Snell's law sinα / C L1 = sinβ / C S2 Calculate its angle of incidence, where α is the angle of incidence, β is the angle of refraction, C L1 is the longitudinal wave speed of ultrasound in organic glass, C S2 is the transverse wave velocity of ultrasound in steel, the calculated α value is consistent with the formula Compare to see whether it meets the incident angle requirements of the steel pipe being probed. If not, it is necessary to select a new probe, re-grind and calibrate it.

[0017] The advantages and positive effects of the present invention are:

[0018] The present invention can eliminate the waste caused by the K value of the arc probe not meeting the requirements by studying a correction method for the wear of the arc probe and a measurement method for the incident point and the K value of the arc probe. Moreover, by measuring the incident point and the K value of the arc probe in real time, the validity of the flaw detection result can be ensured, and the quality of the detected steel pipe can be further guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the measurement diagram of the incident point of the plane probe;

[0020] Figure 2This is the K value measurement diagram of the plane probe (position A);

[0021] Figure 3 This is the K value measurement diagram of the plane probe (positions B and C);

[0022] Figure 4 This is the measurement diagram of the incident point of the arc surface probe;

[0023] Figure 5 This is the K value measurement diagram of the arc surface probe;

[0024] Figure 6 Comparison photos of the wear probe before and after calibration, where (a) is the probe before calibration and (b) is the probe after calibration. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below through specific examples. The following examples are only illustrative and not restrictive, and the protection scope of the present invention cannot be limited thereto.

[0026] A method for correcting arc probe wear, the steps are as follows:

[0027] S1 Grinding: Grind the arc of the worn arc probe into a flat surface;

[0028] S2 test: Use CSK-1A test block to test the incident point of the ground plane probe, and mark the position of the incident point on the side of the probe; use the comparison sample tube to test the K value;

[0029] The method for measuring the incident point is:

[0030] Place the probe in Figure 1 The position of the probe is measured using the reflected wave of the R100 mm arc surface. Then move the probe forward and backward. When the reflected wave is at its highest, the point on the probe wedge pointed by the center mark of the test block R100 is the incident point. Mark the incident point on the side of the probe. It should be noted that the probe should be centered on the test block and should be moved parallel to the side of the test block at a slow speed.

[0031] The measurement method of K value is:

[0032] Place the probe in Figure 2 Position A, use the reflected wave of Φ50mm hole to measure. If the defect echo cannot be found, follow Figure 3 Measure the positions B and C in the figure to find the maximum defect echo. The angle on the test block corresponding to the incident point marked on the probe is the transverse wave refraction angle of the probe. Its tangent value is the K value of the probe.

[0033] It should be noted that in the process of measuring the incident angle and K value, the probe should be centered on the test block and moved parallel to the side of the test block at a slow speed.

[0034] S3 adhesive sheet: stick a plexiglass sheet on the polished probe surface;

[0035] S4 Arc Grinding: Grind the probe after bonding into an arc probe that matches the outer diameter of the steel pipe being probed;

[0036] Glue the pre-prepared plexiglass sheet of the same size as the probe under the probe wafer, and grind out an arc with the same outer diameter as the steel pipe according to the different specifications of the steel pipe. When grinding, first fix a piece of coarse sandpaper close to the surface of the inspected pipe. During the grinding process, use the incident main sound beam line that has been marked on the side of the probe as a reference, and try to keep the incident main sound beam line incident from the highest point of the arc surface of the inspected pipe into the pipe. When the surface of the plexiglass sheet is basically consistent with the arc surface of the pipe, replace it with a piece of water-abrasive fine sandpaper on the surface of the inspected pipe, dip the probe in water and place it on the fine sandpaper for fine grinding until the arc surface of the plexiglass is completely consistent with the arc surface of the pipe, the surface of the plexiglass block is smooth and clean, and the incident main sound beam line basically enters the surface of the pipe from the highest point on the surface of the pipe.

[0037] S5 test: Test the arc probe incident point and K value.

[0038] The method for measuring the incident point is:

[0039] Place the arc surface of the arc probe on the corner of the Dutch test block, such as Figure 4 As shown. Move the probe forward and backward to make the corner echo reach the highest peak. At this time, the point on the probe corresponding to the corner is the actual incident point of the arc probe. Use a pen to mark the incident point on one side of the probe. Measure the length of the front edge of the probe. After comparing it with the new probe, we found that the length of the front edge of the probe is significantly shortened. This shows that the wear of the probe will change the position of the incident point.

[0040] The measurement method of K value is:

[0041] Take a sample tube with artificial trauma (the trauma type is N-shaped or rectangular), place the probe on the outer surface of the tube (coupling agent is applied between the probe and the outer wall of the steel tube to ensure sufficient coupling between the probe and the steel tube), move the probe back and forth to find the maximum reflected wave of the artificial trauma, set the tube marked with the incident point as point A, the artificial defect point as point B, and point D as the midpoint of line segment AB. Figure 5 As shown. From OA=OB=R, we can conclude that triangle ODA is a right triangle.

[0042] Measure the length l of the line segment AB, then in the right triangle ODA we have

[0043] It follows from this

[0044] In triangle AOC, the law of sines gives

[0045] sinβ / r=sinγ / R;(1)

[0046] Again γ = 180° - θ - β; Substituting into (1) we can get

[0047] (where l is the length of line segment AB, r is the inner diameter of the steel pipe, and R is the outer diameter of the steel pipe), then β can be calculated, and the actual K value of the arc probe can be determined, that is, K = tanβ. In actual measurement, multiple measurements should be made in both clockwise and counterclockwise directions of the artificial defect, and the middle value should be taken to ensure the accuracy and effectiveness of the measurement results.

[0048] According to Snell's law sinα / C L1 = sinβ / C S2 Calculate its angle of incidence. Where α is the angle of incidence, β is the angle of refraction, C L1 is the longitudinal wave speed of ultrasound in organic glass, C S2 is the transverse wave velocity of ultrasound in steel. The calculated α value is consistent with the formula Compare to see whether it meets the incident angle requirements of the steel pipe being probed. If not, a new probe needs to be selected for re-grinding and calibration.

[0049] The above description is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept, which all belong to the protection scope of the present invention.

Claims

1. A method for correcting arc probe wear, characterized in that: Here are the steps: S1 Grinding: Grind the arc of the worn arc probe into a flat surface; S2 test: Use CSK-1A test block to test the incident point of the ground plane probe, and mark the position of the incident point on the side of the probe; use the comparison sample tube to test the K value; S3 adhesive sheet: stick a plexiglass sheet on the polished probe surface; S4 Arc Grinding: Grind the probe after bonding into an arc probe that matches the outer diameter of the steel pipe being probed; S5 test: Test the arc probe incident point and K value.

2. The arc probe wear correction method according to claim 1, characterized in that: The specific method of S4 is: when grinding, first fix a piece of coarse sandpaper close to the surface of the inspected pipe. During the grinding process, use the incident main sound beam line marked on the side of the probe as a reference, and try to keep the incident main sound beam line incident from the highest point of the arc surface of the inspected pipe to enter the pipe. When the surface of the organic glass sheet and the arc surface of the pipe are basically consistent, replace it with a piece of water-abrasive fine sandpaper on the surface of the inspected pipe, dip the probe in water and place it on the fine sandpaper for fine grinding until the arc surface of the organic glass and the arc surface of the pipe are completely consistent, the surface of the organic glass block is smooth and bright, and the incident main sound beam line basically enters the surface of the pipe from the highest point on the surface of the pipe.

3. The arc probe wear correction method according to claim 1, characterized in that: The test method for the incident point of the arc probe described in S5 is: place the arc surface of the arc probe on the corner of the Dutch test block, move the probe back and forth to make the corner echo reach the highest peak, then the point on the probe corresponding to the corner is the actual incident point of the arc probe, and mark the incident point on one side of the probe with a pen.

4. The arc probe wear correction method according to claim 3, characterized in that: S5 The measuring method of the arc probe K value is as follows: take a sample tube with artificial trauma, place the probe on the outer surface of the tube, move the probe back and forth to find the maximum reflected wave of the artificial trauma, set the tube where the incident point is marked as point A, set the artificial defect point as point B, set point D as the midpoint of line segment AB, OA=OB=R, and the triangle ODA is a right triangle, line segment OA is the line connecting the tube center point O and point A, line segment OB is the line connecting the tube center point O and point B, line segment AB is the line connecting point A and point B, line segment OD is the line connecting the tube center point O and point D, and point C is the intersection of line segment OD and the inner wall of the tube; θ is the angle between line segment OA and line segment OD, β is the angle between line segment OA and line segment AC, γ is the angle between line segment AC and line segment OC, r is the inner diameter of the steel tube, R is the outer diameter of the steel tube, and the length of the line segment AB is l, The actual K value of the arc probe is equal to tanβ, which is calculated by the following formula:

5. The arc probe wear correction method according to claim 4, characterized in that: After step S5, according to Snell's law sinα / C L1 = sinβ / C S2 Calculate its angle of incidence, where α is the angle of incidence, β is the angle of refraction, C L1 is the longitudinal wave speed of ultrasound in organic glass, C S2 is the transverse wave velocity of ultrasound in steel, the calculated α value is consistent with the formula Compare to see whether it meets the incident angle requirements of the steel pipe being inspected. If not, You need to select a new probe, re-grind and calibrate it.

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