JPH07128304A - Oblique angle probe for socket welding joint ultrasonic flaw inspection - Google Patents

Abstract

PURPOSE:To provide an oblique angle probe for socket welding joint ultrasonic flaw inspection which can inspect flaw over a wide range while enhancing SN. CONSTITUTION:A transmitting section 15 and a receiving section 16 are disposed in front and rear in the flaw detecting direction. The plane 19a for fixing a receiving oscillator 20 of a wedge 19 on the receiving side is inclined slightly against the plane 17a for fixing a transmission oscillator 18 of a wedge 17 on the transmitting side and the focal point for transmitting/receiving ultrasonic wave is located at the flaw part 12a of an object 12 to be inspected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bevel probe for ultrasonic flaw detection of a socket weld joint, and more particularly to a socket weld joint super joint capable of performing a flaw detection inspection over a wide range and further improving a flaw detection sensitivity. The present invention relates to a bevel probe for ultrasonic flaw detection.

[0002]

2. Description of the Related Art For example, in various pipes used in a nuclear power generator, contents such as cooling water of a nuclear reactor may flow out if a welded portion has a defect. However, non-destructive inspection of welds using a radiation transmission test is performed. By the way, since it is difficult to inspect a raised weld such as a socket weld while applying a probe, a bevel angle probe is used to inspect from a partial flaw detection surface (hereinafter referred to as flaw detection surface) slightly apart from the weld. It is inspected using a tentacle. Next, a conventional bevel probe for ultrasonic flaw detection will be described with reference to FIGS.

As shown in FIG. 4, the bevel probe 100 is
In the casing 101, an ultrasonic wave transmission section 103 and an ultrasonic wave reception section 104 partitioned by a sound absorbing material 102 are arranged side by side in the lateral direction with respect to the flaw detection direction. The transmitting unit 103 is provided with a transmitting wedge 105 and a flat plate-shaped transmitting oscillator 106 attached to the transmitting wedge 105, and the receiving unit 104 includes a receiving wedge 107 and a receiving wedge 107. Plate-shaped receiving oscillator 108 to be attached
Is provided. Transmitting oscillator 106 and receiving oscillator 108
Is provided in such a manner that the focal point a for transmitting and receiving ultrasonic waves is tilted in a chevron shape so as to have a certain depth obliquely forward from the flaw detection surface of the socket 109. The lower surfaces of the transmitting and receiving wedges 105 and 107 are flat. For example, when ultrasonically inspecting the socket welding portion 111 of the cylindrical pipe 110 as shown in FIG. 5, a contact medium such as grease is applied to the end portion of the socket 109 on the socket welding portion 111 side. While applying the lower surface of the bevel probe 100 to the coating portion, the bevel probe 1
00 in the direction of the arrow in FIG.
The ultrasonic flaw detection test of 1 is performed. That is, ultrasonic waves are generated from the transmission vibrator 106 to which the pulse voltage is applied, and the ultrasonic waves pass through the transmission-side wedge 105 and the socket 109.
It enters the socket 109 from the flaw detection surface and is fired diagonally forward. If the socket weld 111 has a defect, the defect echo reflected by the defect 112 will be
From 0 to the receiving side wedge 107 and the receiving oscillator 108
Vibrate. Thereby, the defect echo is detected.

[0004]

However, in the conventional bevel probe 100 for ultrasonic flaw detection as described above, the transmitter 103 and the receiver 104 are arranged side by side in the lateral direction of the bevel probe 100 as described above. Moreover, since the lower surfaces of the transmitting and receiving wedges 105 and 107 are flat, contacting the surface of the cylindrical socket 109 during flaw detection has no relation to ultrasonic wave transmission / reception. The sound absorbing material 102 is provided at the center of the lower surface of the child 100. For this reason, ultrasonic waves are transmitted and received from the flaw detection surface via the contact medium such as the grease, and as a result, the angle of incidence and reflection with respect to the focal position increases, the efficiency of ultrasonic transmission and reception decreases, and the SN ratio deteriorates. . Further, in this way, the transmission oscillator 106 and the reception oscillator 108 are
However, in the arrangement adjacent to each other with the sound absorbing material 102 interposed, it is difficult to estimate the defect height from the defect echo height because the change rate of the defect echo height due to the change of the defect height is small. It was The present invention has been made in view of such circumstances, and an object of the present invention is to provide a bevel probe for socket welding joint ultrasonic flaw detection that can perform flaw detection over a wide range and further improve the SN ratio. To do.

[0005]

A method according to the above-mentioned object.
An oblique angle probe for ultrasonic flaw detection of a socket welding joint described is a transmitter having a transmitting wedge and a flat plate-shaped transmitting oscillator attached to the transmitting wedge, and a receiving wedge and the receiving wedge. Socket welded joint ultrasonic probe for ultrasonic flaw detection including a receiver having a flat plate-shaped receiver attached thereto, a sound absorbing material separating the transmitter and the receiver, and a casing accommodating these In, while arranging the receiving unit and the transmitting unit before and after the flaw detection direction, the mounting surface of the receiving transducer of the receiving wedge is slightly inclined with respect to the mounting surface of the transmitting transducer of the transmitting wedge, The focus of the transmission and reception is arranged at the flaw detection portion of the inspection object.

[0006]

In the case of performing ultrasonic flaw detection using the bevel probe for ultrasonic flaw detection of the socket welded joint according to claim 1,
For example, if necessary, apply a contact medium such as grease to the flaw detection surface on the front side of the welded portion of the inspection object, and perform ultrasonic flaw detection inspection of the welded portion while applying the lower surface of the bevel probe to this application portion. Then, an ultrasonic wave is emitted into the inspection object from a transmitter arranged, for example, behind the probe, and if there is a defect, it is reflected from the defect and becomes a defect echo, for example, in front of the probe. It will be returned to the receiver placed in. In this case, since the ultrasonic waves are efficiently transmitted and received from the bevel probe, the SN ratio can be improved. Further, it is possible to increase the rate of change in the defect echo height associated with the change in defect height, and improve the accuracy of estimating the defect height.

[0007]

Embodiments of the present invention will now be described with reference to the accompanying drawings to provide an understanding of the present invention. Here, FIG. 1 is an enlarged sectional view in a flaw detection direction of a bevel probe for ultrasonic flaw detection of a socket welded joint according to an embodiment of the present invention, FIG. 2 is a sectional view in the same width direction, and FIG. It is a side view shown.

As shown in FIG. 3, a bevel probe 10 for ultrasonic flaw detection of a socket weld joint according to an embodiment of the present invention.
Is for performing a flaw detection inspection of a socket welded portion 12a in which a pipe 11 and a socket 12 are welded, which is an example of an inspection object. As shown in FIGS. 1 and 2, a socket welding joint ultrasonic flaw detection probe 10 for ultrasonic flaw detection is divided into a casing 13 made of horizontally long stainless steel having a short front-rear direction by a sound absorbing material 14 inclined obliquely forward and downward. Ultrasonic wave transmitting unit 15
The receiver 16 and the receiver 16 are arranged so that the transmitter 15 is located behind the bevel probe 10 and the receiver 16 is located in front of the bevel probe 10. The sound absorbing material 14, the transmitting unit 15, and the receiving unit 16 have a length substantially equal to the width of the casing 13.

The transmitting portion 15 is made of synthetic resin and has a plate-shaped transmitting oscillator 18 attached to a rearwardly inclined surface 17a of the transmitting wedge 17 which is inclined downward.
In addition, the reception unit 16 has a reception-side wedge 19 made of synthetic resin, and a flat-plate reception oscillator 20 attached to a rearwardly inclined surface 19a of the reception-side wedge 19. ing. The transmitter and receiver transducers 18, 20 are
Both are well-known vibrators in which electrodes are fixed to both surfaces of a vibration plate made of, for example, lead zirconate titanate. Further, the lower surfaces of the transmitting wedge 17 and the receiving wedge 19 are flat surfaces, but the present invention is not limited to this, and they may be curved surfaces along the outer peripheral surface of the socket 12, for example. Here, as shown in FIG. 1, the inclination angles θ of the respective rear inclined surfaces 17a and 19a.
1 and θ2 are angles for inclining the transmission oscillator 18 and the reception oscillator 20 so that the transmission / reception focus a can be located at the flaw detection portion or slightly ahead of the flaw detection portion. Specifically, the inclination angle θ1 of the rear inclined surface 17a of the transmitting wedge 17 is 29.5.
The inclination angle θ2 of the rear inclined surface 19a of the reception-side wedge 19 is 35.3 degrees, and longitudinal waves are positively used as ultrasonic waves. The inclination angle θ3 of the front inclined surface 19b of the reception-side wedge 19 which is the inclination angle of the sound absorbing material 14 is 60.5 degrees.

Next, the operation of the bevel probe 10 for ultrasonic flaw detection of a socket weld joint according to the present invention will be described. When ultrasonically inspecting the socket welding portion 12a of the cylindrical pipe 11 as shown in FIG. 3, a contact medium such as grease is applied to the end portion of the socket 12 on the socket welding portion 12a side, and this application portion While the lower surface of the bevel probe 10 is being applied to the bevel probe 10, the bevel probe 10 is moved in the direction of the arrow in the figure to perform an ultrasonic flaw inspection of the socket weld 12a. That is, as shown in FIG. 1, ultrasonic waves are periodically generated from the transmission oscillator 18 to which the pulse voltage is applied, the ultrasonic waves pass through the transmission wedge 17, and are detected from the flaw detection surface of the socket 12 by the socket 12. It enters inside and is fired toward the flaw detection part diagonally forward. When the socket weld 12a has a defect, the defect echo reflected by the defect 12b passes from the pipe 11 through the receiving wedge 19 and is transmitted to the receiving oscillator 20 where it is converted into an electric signal and the defect echo height is detected. To be done.

As described above, ultrasonic waves are directly emitted from the transmitting portion 15 arranged behind the bevel probe 10 toward the flaw detection portion in the socket welding portion 12a, and when there is a defect, a defect echo is generated. Then, since it directly returns to the receiving unit 16 arranged in front of the bevel probe 10, the transmitting unit 15 and the receiving unit 16 as in the conventional means are arranged in the lateral direction of the bevel probe 10. Compared with the object, the direct contact with the inspection object through the thin contact medium enables efficient transmission / reception, so that the flaw detection sensitivity does not decrease.

The present invention is not limited to this embodiment, and any change in design within the scope of the invention is included in the present invention. For example, in the embodiment, the bevel probe for ultrasonic flaw detection of the socket weld joint was used for flaw detection of the socket weld portion of the pipe, but the invention is not limited to this, but butt welding of elbow, cheese or pipe etc. It may also be used for flaw detection inspection of parts.

[0013]

According to the bevel probe for ultrasonic flaw detection of a socket welded joint according to the first aspect of the invention, as described above, for example, from the transmitting portion arranged behind the bevel probe to the flaw detection portion in the weld portion. Ultrasonic waves are emitted toward the receiver, and if there is a defect, it will be returned as a defect echo to the reception unit arranged in front of, for example, the bevel probe. The rate of change in depth became large, and it became easier to estimate the defect height from the defect echo height. Also,
Since the receiving part and the transmitting part are arranged in front of and behind the bevel probe, even if the inspection object has a rounded shape, the central part of the wedge of the probe can directly contact the inspection object for inspection. The SN ratio can be significantly improved.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view in a flaw detection direction of a bevel probe for ultrasonic flaw detection in a socket welded joint according to an embodiment of the present invention.

FIG. 2 is a sectional view in the same width direction.

FIG. 3 is a side view showing the same usage state.

FIG. 4 is a schematic enlarged front view showing a usage state of a bevel probe for ultrasonic flaw detection in a socket welded joint according to a conventional means.

FIG. 5 is a side view showing the same usage state.

[Explanation of symbols]

 10 Socket Weld Joint Bevel Probe for Ultrasonic Testing 11 Pipe 12 Socket 12a Socket Weld 12b Defective 13 Casing 14 Sound Absorbing Material 15 Transmitter 16 Receiver 17 Transmit Side Wedge 17a Backward Slope 18 Transmitter 19 Receive Side wedge 19a Rear inclined surface 20 Receiving transducer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masago Kawamura Inventor Masataka Kawamura 4-10-13 Ibori, Kokurakita-ku, Kitakyushu City, Fukuoka Prefecture (72) Inventor Masayuki Imabashi, Kokurakita-ku, Kitakyushu, Fukuoka Ibori 4-chome 10-13 New Japan Non-Destructive Inspection Co., Ltd. (72) Inventor Kunimichi Watanabe 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Stock Company Toshiba Yokohama Office (72) Inventor Kunio Kawamata Tokyo 3-7-1, Nishi-Shimbashi, Minato-ku, Toshiba Plant Construction Co., Ltd.

Claims (1)

[Claims] 1. A receiver having a transmitter wedge and a plate-shaped transmitter vibrator attached to the transmitter wedge, and a receiver having a receiver wedge and a plate-shaped receiver vibrator attached to the receiver wedge. In a bevel probe for ultrasonic welding flaw detection of a socket welding joint provided with a sound absorbing material that partitions the transmitting section and the receiving section, and a casing that houses these, flaw detection is performed on the receiving section and the transmitting section. In addition to the front and rear directions, the mounting surface of the receiving oscillator of the receiving wedge is slightly inclined with respect to the mounting surface of the transmitting oscillator of the transmitting wedge, and the focus of ultrasonic transmission and reception is located at the flaw detection part of the inspection object. Socket welded joint ultrasonic probe for angle flaw detection.