JPH11326296A - Ultrasonic probe calibration method and ultrasonic flaw detector - Google Patents

Abstract

(57) [Summary] [Problem] Off-line calibration and verification of a probe under the same conditions as an actual line using a calibration test piece with a flat bottom hole and a flat bottom slit-shaped artificial flaw processed I do. SOLUTION: Calibration test pieces 4 and 5, each having an artificial flaw of a flat bottom hole 8 and a flat bottom slit 7 formed on the back surface, are attached to the outside of a conveying line of a steel plate 1, and attached to an inside cart and an edge cart of an ultrasonic flaw detector. The probe heads 2, 3 are scanned in the direction perpendicular to the flat bottom slit 8 at the same speed as during online flaw detection, flaw detection is performed on the calibration test piece, and the normality and abnormality are displayed for each probe. To inspect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for calibrating an ultrasonic probe and an ultrasonic flaw detector, and a calibration test piece is mainly provided outside a production line for a thick steel plate, and the same conditions as those of an actual line are used. The present invention relates to a technology that enables off-line probe calibration and verification.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 4-37948 discloses a method for automatically checking the defect detection performance of a probe in an automatic ultrasonic flaw detector for a thick plate. In this probe verification method, a flat-bottomed slit-shaped artificial flaw is processed in a direction parallel to the transport line traveling direction on a calibration test piece for off-line checking installed outside the transport line, and is orthogonal to the flat-bottom slit-shaped artificial flaw. The probe heads, each containing a plurality of probes, arranged in the direction to be scanned, scan in the direction orthogonal to the flat-bottomed slit-shaped artificial flaw, and display the results to show the soundness of all the probes. Confirmation can be performed simultaneously and automatically. However, this transducer verification method
Originally, a flat bottom hole should be replaced with a flat bottom slit flaw to improve the efficiency of the verification work. Therefore, strictly speaking, the reflectance differs between the flat-bottom hole and the flat-bottom slit flaw due to the size and shape of the defect, so that a slight difference occurs in the probe sensitivity and detection performance.

[0003]

On the other hand, there are standards or users who require verification with a flat bottom hole. Therefore, this request cannot be met. According to the customer's request, under the same conditions as the actual line, ・ A defect of a known size must be reliably detected at the correct position ・ A correct evaluation judgment level ・ A defect should not be detected at a defect-free part ・ Scanning direction The defect detection position in the direction perpendicular to the direction is normal.If it is necessary to submit data for the above proof, conventionally, a defect-free thick plate for test certification is prepared and the specified position and dimensions are specified. The data were collected by processing a flat-bottom hole-shaped defect and actually performing flaw detection. However, according to this method, preparation, processing, storage, and transportation of a thick plate for test certification require much labor and cost, and it is difficult to perform it in a short time.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and uses a calibration test piece in which a flat-bottomed hole and a flat-bottomed slit-shaped artificial flaw are machined, under the same conditions as the actual line. An object of the present invention is to provide a method of calibrating an ultrasonic probe and an ultrasonic flaw detector which enable calibration and verification of the probe off-line.

[0005]

According to the present invention, there is provided a method for calibrating an ultrasonic probe, comprising the steps of: providing a plurality of calibration test pieces having flat-bottomed holes and flat-bottomed slit-shaped artificial flaws formed on a back surface thereof; The flat bottom slit-shaped artificial flaws are arranged in the direction of the transport line so as to be in a straight line parallel to the transport line, and all the probe heads are connected to the transport line at the same scanning speed as during online flaw detection of steel sheets. By performing ultrasonic flaw detection on the corresponding calibration test pieces by scanning in the direction at right angles, calibration and verification based on the detection results are performed for all the probes provided in the probe head. It is characterized by the following.

In the ultrasonic flaw detector according to the present invention, a flat-bottomed hole and a flat-bottomed slit-shaped artificial flaw are machined on the back surface, and the flat-bottomed slit-shaped artificial flaw is parallel to the transport line outside the steel sheet transport line. A plurality of calibration test pieces arranged in the transport line direction so as to be linear, and a plurality of probes are arranged in a staggered manner, and a probe head supported so as to be able to move up and down,
A plurality of the probe heads are attached, movable in the width direction of the steel plate, and a carriage means for moving the probe head onto the calibration test piece, and an ultrasonic wave installed on a steel plate transport line. The apparatus includes a flaw detector and display means for displaying a detection result for each of the probes.
The cart means is composed of an inside cart and an edge cart.

In the present invention, a square-shaped calibration test piece having a flat-bottomed hole and a flat-bottomed slit-shaped artificial flaw formed on a back surface at a specific position and size is provided by the same number as the number of probe heads. In the vicinity of the outside of the transfer line, artificial slits having a flat bottom slit shape are arranged in a straight line parallel to the transfer line. The probe head is one in which a plurality of probes are arranged in a staggered manner.A plurality of such probe heads are mounted so that they can be moved up and down and moved in the width direction of the steel plate. When calibrating the probe, scan all probe heads in the direction perpendicular to the flat-bottom slit-shaped artificial flaw on the corresponding calibration test specimen at the same scanning speed as that for online flaw detection of steel plates. To perform ultrasonic flaw detection. At this time, it is possible to inspect whether all the probes of each probe head have detected the flat-bottom slit-shaped artificial flaw at the correct position and size. It can be inspected whether the flaw is detected at the regular position and size, and whether the other probe has not detected the artificial flaw in the flat bottom hole. When an abnormality of the probe is found, the probe is calibrated and verified, the result is displayed, and it is determined whether the probe is appropriate. In this manner, calibration and verification of all the probes can be performed at once under the same conditions as online, and adjustment with high accuracy and efficiency can be performed.

[0008]

FIG. 1 is a diagram showing an outline of a probe calibration method according to the present invention. In FIG. 1, reference numeral 1 denotes a thick steel plate as a material to be inspected, which is intermittently conveyed (shifted) in the direction of arrow a. Reference numeral 2 denotes a plurality of inside probe heads attached to the inside cart of the ultrasonic flaw detector 10 via a lifting shaft, which are movable in the width direction of the steel plate 1 (in the direction of arrow b). The flaw detection is performed on the inner part excluding the edge part of No. 1. Reference numeral 3 denotes an edge probe head for detecting a flaw on an edge portion of the steel plate 1, which is attached to the edge carriage via a lifting shaft. The edge carriage can also move in the direction of arrow b. 4 is a plurality of calibration test pieces arranged by the same number corresponding to each inside probe head 2, 5 is a plurality (2 pieces) arranged by the same number corresponding to each edge probe head 3 These calibration test pieces 4 and 5 are arranged in the vicinity of the outside of the transport line such that flat-bottom slit-shaped artificial flaws described later are linearly parallel to the transport line. . Further, the ultrasonic flaw detector 10 having the inside cart and the edge cart is installed on the conveyance line of the steel plate 1, and the moving distance of the inside cart and the edge cart is determined by the calibration test pieces 4, 5 attached outside the conveyance line. It extends up.

Each of the calibration test pieces 4 and 5 has the same structure. As shown in FIG. 2, one of the test pieces 4 and 5 has a flat bottom surface on a precision-finished square defect-free metal plate 6. The slit-shaped artificial flaw 7 and the artificial flaw 8 of the flat bottom hole have the same hole diameter, hole depth,
One flat bottom slit 7 and one flat bottom hole 8 are precisely machined at a specific position from the origin of the metal plate 6 with a slit width, a slit depth, and a slit length.

Each of the inside probe head 2 and the edge probe head 3 has the same configuration, and a plurality of probes 9 are arranged in a staggered pattern as shown in FIG. In this case, since the flaw detectable range 11 of each probe 9 is determined, each probe 9 is arranged so as to have a continuous flaw detectable range 12 per head as a whole. Therefore, the hatched portion 13 in FIG. 1 indicates the flaw-detected area of the edge portion where the flaw detection has been completed by the probe head 3 of the edge bogie, and 14 indicates the flaw-detected area of the inside portion by each probe head 2 of the inside bogie. Show. The inside probe heads 2 are arranged at equal intervals. However, after moving in the direction b from end to end of the steel plate 1, it is separated from the steel plate 1, and then the steel plate 1 is moved by one pitch by the transfer table. Then, since the probe head 2 returns in the direction b again after the contact, the flaws in the gaps between the probe heads 2 can be detected. Therefore, the entire surface of the steel plate 1 can be detected by the inside probe head 2 and the edge probe head 3.

FIG. 6 is a diagram showing the system configuration of the ultrasonic flaw detector according to the present invention. The scanning speed of the inside cart 15 and the edge cart 16 is controlled by a cart controller 17,
In addition, the ultrasonic signal for each of the inside probe head 2 and each of the edge probe heads 3 of the inside cart 15 and the edge cart 16 is subjected to transmission / reception control and processing for each probe channel by the flaw detection signal processing device 18. By processing the scanning pulse signal from the carriage control device 17 and the defect detection signal from the flaw detection signal processing device 18 by the data processing device 19, the flaw detection result (presence / absence / position / size, etc.) of the steel plate 1 and calibration The calibration results (position, size, etc. of the artificial flaw) for the test pieces 4, 5 are displayed on the CRT 20 for each probe channel.

Next, a probe calibration method according to this embodiment will be described. The calibration test pieces 4 and 5 are arranged and fixed outside the transport line of the steel sheet 1 as shown in FIG.
Since the flat bottom slits 7 as artificial flaws are arranged in a straight line parallel to the transport line, the inside bogie 1
5 and the edge carriage 16 are moved in the direction c outside the transfer line at the same scanning speed as in the online flaw detection, and the calibration probe 4 corresponding to each of the inside probe heads 2 and each edge probe are moved. The calibration test pieces 5 corresponding to the respective heads 3 are subjected to ultrasonic flaw detection. FIG.
, The S-side calibration test piece 5a is for the edge probe head 3a attached to the S-side edge carriage, and the N-side calibration test piece 5b is the edge attached to the N-side edge carriage. This is for the probe head 3b.

For convenience of explanation, taking one probe head 2 as an example, the flaw detection with the corresponding calibration test piece 4 will be described. As shown in FIG. 2, when the probe head 2 moves the calibration test piece 4 in the direction c, the scanning direction is a direction orthogonal to the flat bottom slit 7, and thus the probe head 2 is provided on the probe head 2. Each probe 9 must detect the flat bottom slit 7 under the same conditions. That is, it is required to detect the flat bottom slit 7 at the same position and the same size. The detection result is displayed on the CRT 20 of FIG. 6 for each probe, whereby it is determined whether the probe is normal or abnormal.
If the probe is determined to be abnormal, of course, appropriate measures, calibration, etc. (for example, the mounting state of the probe,
Wiring check, etc.), and verify the calibration results. Next, the probe head 2 is continuously moved in the direction c to detect a flaw in the flat bottom hole 8. Since one flat bottom hole 8 is provided at a predetermined position, only a specific probe 9 passing over the flat bottom hole 8 detects the flat bottom hole 8 and no other probes 9 are detected. Is required. If a detection result contrary to this is displayed, the probe 9 is naturally determined to be abnormal. The same calibration as above is performed on the probe determined to be abnormal. In this way, all the probes 9 of all the probe heads 2 and 3 can be inspected, and calibration and verification can be performed at one time off-line. Moreover, it is possible to submit certification data not only to the flat bottom slit 7 but also to the flat bottom hole 8 under the same conditions as in the online flaw detection. Then, after the calibration is completed, flaw detection for the actual steel plate 1 can be performed online.

[0014]

As described above, according to the present invention,
Using a calibration test piece with a flat-bottomed hole and a flat-bottom slit-shaped artificial flaw, ultrasonic testing was performed on the calibration test piece at the same scanning speed as during online flaw detection, and all probe heads were scanned. By displaying the detection result for each probe, the probe can be inspected, and calibration and verification can be performed at once off-line. In addition, it is possible to submit certification data for flat bottom holes.Furthermore, under the same conditions as the actual line, defects of known dimensions must be reliably detected at the correct position and at the correct evaluation judgment level. It is possible to easily respond to a request for submission of proof data that no defect is detected and that the defect detection position in the direction orthogonal to the scanning direction is normal.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a probe calibration method of the present invention.

FIG. 2 is a plan view of a test piece for calibration.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a sectional view taken along line BB of FIG. 2;

FIG. 5 is an explanatory diagram of a probe head.

FIG. 6 is a system configuration diagram of the ultrasonic flaw detector according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel plate 2 Inside probe head 3 Edge probe head 4 Calibration test piece 5 Calibration test piece 6 Metal plate 7 Flat bottom slit-shaped artificial flaw 8 Flat bottom hole artificial flaw 9 Probe 10 Ultrasonic flaw detector 11 Probe Child flaw detectable range 12 Probe head flaw detectable range 13 Edge flaw-detected area 14 Inside flaw-detected area 15 Inside bogie 16 Edge bogie 17 Bogie controller 18 Flaw detection signal processor 19 Data processor 20 CRT

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yu Nakajima 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Inside Nihon Kokan Co., Ltd. (72) Inventor Yuki Iizuka 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (72) Inventor Shigeyuki Ohno 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Yukio Mitani 2-3-2 Marunouchi, Chiyoda-ku, Tokyo 3 Rishi Electric Co., Ltd. Inside the corporation

Claims (3)

[Claims] 1. A plurality of test pieces for calibration having a flat-bottomed hole and a flat-bottomed slit-shaped artificial flaw machined on the back side, and a flat-bottomed slit-shaped artificial flaw is formed in a straight line parallel to the transfer line outside the steel sheet transfer line. Are arranged in the direction of the transport line so that all the probe heads are scanned in the direction perpendicular to the transport line at the same scanning speed as during the online flaw detection of the steel sheet, and the corresponding probe for the calibration test specimen is scanned. A method of calibrating an ultrasonic probe, comprising: performing ultrasonic wave testing to perform calibration and verification based on detection results for all probes provided in the probe head. 2. A flat-bottomed hole and a flat-bottomed slit-shaped artificial flaw are machined on the back surface, and the flat-bottomed slit-shaped artificial flaw is formed on the outer side of the steel sheet conveying line in a direction parallel to the conveying line. A plurality of test pieces for calibration arranged, a plurality of probes are arranged in a staggered manner, a probe head supported so as to be able to move up and down, and a plurality of the probe heads are attached, in the width direction of the steel plate. An ultrasonic flaw detector which is movable and has a carriage means for moving the probe head on the calibration test piece, and which is installed on a steel sheet conveying line; and And a display means for displaying a detection result. 3. The ultrasonic flaw detector according to claim 2, wherein said bogie means comprises an inside bogie and an edge bogie.