JPH0862188A - Ultrasonic array flaw detection method for shear wave oblique angle and array-type flaw detection equipment used in this flaw detection method - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve accuracy in ultrasonic array flaw detection for transverse wave oblique angles. [Structure] A plurality of transducers 3 in an array probe 1 are driven at the same time, and by controlling the drive timing, only a transverse wave is made incident on a subject and a transverse wave oblique angle is controlled. Ultrasonic array flaw detection method and apparatus therefor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic array flaw detection method for transverse wave bevels for flaw detection in steel and welds using an ultrasonic beam, and an array flaw detection apparatus used in this flaw detection method.

[0002]

2. Description of the Related Art A probe of an ultrasonic array flaw detector which has been conventionally used is, as shown in FIG. 5, a system in which a transducer b is mounted on a plane in a probe a to perform vertical flaw detection, 6 is a longitudinal wave oblique angle flaw detection method. Further, as shown in FIG. 7, the conventional shear wave angle probe generates shear waves by attaching a shoe c of acrylic, for example, to a single oscillator. In FIG. 7, d is a sound absorbing material for reducing ultrasonic reflection inside the shoe.

[0003]

However, the above conventional example has the following problems. a. In the conventional longitudinal wave bevel, a transverse wave is generated at the same time as the longitudinal wave. Further, if the angle of incidence is increased, the spread of the ultrasonic beam becomes large, and both the flaw detection sensitivity and the accuracy decrease. As a result, it is difficult to use when ultrasonic waves must be incident on the subject at a large angle, such as when inspecting thin-walled material welds. b. Angle beam flaw detection with a conventional ultrasonic array probe is performed by controlling the transmission timing of the transducers, but the larger the angle, the larger the deviation in transmission time between the transducers, and the overall accuracy increases. It tends to fall, and it becomes difficult to obtain an ideal transmitted wave. Further, the beam will be emitted in a direction other than the desired direction, and the flaw detection accuracy will be reduced. c. Japanese Examined Patent Publication No. 60-236061 describes a method of performing focusing with a refraction angle by using an array type ultrasonic probe, but this method does not require ordinary focusing. It is difficult to apply for flaw detection. d. A single-transducer transverse-wave oblique-angle probe has a fixed refraction angle, and it is necessary to prepare a plurality of probes according to the sound velocity of an object to be inspected. Although there is a variable angle type for improving it, it is difficult to set an angle and it is difficult to obtain a stable angle. e. Conventionally, two types of methods, manual and automatic, are currently used for scanning the probe, but in any case, it takes a lot of labor and time, and the scanning speed is limited by the viscosity of the contact medium. It An object of the present invention is to propose an ultrasonic array flaw detection method for transverse wave oblique angles and an array type flaw detection apparatus used in this flaw detection method, which solves the above problems a to e.

[0004]

The structure of an ultrasonic array flaw detection method for transverse wave oblique angles and an array type flaw detection apparatus used in this flaw detection method according to the present invention are as follows. 1. By driving multiple transducers at the same time and controlling the drive timing, only transverse waves are incident on the subject, the incident angle and focus position are controlled, and the transducer group to be used is selected. Ultrasonic array flaw detection method for transverse wave bevels that performs scanning by performing the following methods. 2. An array probe having a plurality of vibrators attached to a shoe for setting an angle of inclination, and a vibrator and a delay setting device for setting the drive timing of the vibrator to be driven among the vibrators in the array probe And an ultrasonic flaw detector that drives the oscillator based on the set delay amount of the delay setting device to transmit and receive to the oscillator, and receives the waveform signal from the oscillator that detected the reflected wave and processes this signal And a signal recorder for storing and displaying the signal as necessary,
Ultrasonic array flaw detector for transverse wave bevel. 3. 3. The ultrasonic array flaw detection method for transverse wave oblique angles according to 1 or 2 above, wherein the shoe is made of acrylic, and the array type flaw detection device used in this flaw detection method.

[0005]

Operation: The drive timing of the vibrator is input to the delay setting device in advance, and a plurality of vibrators are driven at the timing based on the setting of the delay setting device. The ultrasonic waves emitted from these transducers are phase-synthesized in the shoe and transmitted from the shoe into the subject at a set angle or at a focal position. The ultrasonic waves reflected and returned by the reflector in the subject are received by the transducer, and the waveform signal is processed. When scanning is performed, ultrasonic waves are transmitted and received in exactly the same manner as described above, except that the transducer is shifted by one. As a result, the transmission position of the ultrasonic beam shifts by one oscillator. In this way, the transducers are sequentially shifted one by one, and while this control is automatically performed using the electronic circuit, the inspection site of the subject is thoroughly scanned.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a transverse wave array flaw detector according to the present invention. In FIG. 1, 1 is an array probe, 2 is a shoe made of acrylic having an oblique angle 2a, and 3 is a vibrator attached to the oblique angle 2a of the shoe 2. In addition, shoe 2
When the angle of refraction 2a is, for example, a refraction angle of 70 degrees in steel, the transverse wave sound velocity is 3230 m / s and the longitudinal wave sound velocity of the shoe 2 is 2730 m.
/ S, the oblique angle of the shoe 2 is 52.5 degrees.
Further, as a method of attaching the vibrator to the shoe, there are screwing and the like in addition to the sticking. However, the sticking, which has been widely used for the conventional single vibrator and the like, is considered to have high reliability and is desirable. Reference numeral 4 is a delay setting device, and the delay setting device 4 sets the drive timing of the vibrator 3. The phased array flaw detector 5 drives each transducer 3 based on the set value of the delay setter 4.

In the above embodiment, the drive timing of the vibrator 3 is input to the delay setting device 4 in advance, and the plurality of vibrators 3 are driven at the timing based on the setting of the delay setting device. (Figure 3). The ultrasonic waves emitted from the transducers 3 are phase-synthesized in the shoe 2 and transmitted from the shoe 2 into the subject at a set angle or at a focal position. The ultrasonic wave reflected and returned by the reflector in the subject is received by the transducer 3 and the waveform signal is processed. When scanning is performed, ultrasonic waves are transmitted and received in exactly the same manner as described above except that the transducer 3 is shifted by one (FIG. 4). As a result, the transmission position of the ultrasonic beam is displaced by one oscillator 3. In this way,
While the transducers 3 are sequentially shifted one by one, and this control is automatically performed by using an electronic circuit, the inspection points of the subject are thoroughly scanned.

[0008]

The effects of the present invention are as follows. a. By using the bevel shoe, only transverse waves can be incident on the subject. b. By controlling the excitation (driving) timing of the array transducer, it is possible to deal with the variation in the sound velocity of the subject only by controlling the timing. c. By electronically scanning, the time required for measurement can be shortened.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an ultrasonic array flaw detection method for shear wave oblique angles and a shear wave array flaw detection apparatus according to the present invention.

FIG. 2 is an explanatory diagram of a probe.

FIG. 3 is an explanatory diagram of a state in which a plurality of vibrators are simultaneously driven among a plurality of vibrators.

FIG. 4 is an explanatory diagram of a situation in which a vibrator is driven by shifting one unit.

FIG. 5 is an explanatory diagram of a conventional probe that generates a longitudinal wave.

FIG. 6 is an explanatory diagram of a conventional probe that generates a transverse wave.

FIG. 7 is an explanatory diagram of a transverse wave bevel angle simple vibration probe.

[Explanation of symbols]

 1 probe 2 shoe 2a bevel 3 transducer 4 delay setting device 5 phased array flaw detector 6 signal processor 7 data recorder

Claims (3)

[Claims] 1. A plurality of transducers are simultaneously driven, and by controlling the drive timing, only transverse waves are incident on a subject, and the angle of incidence and the focal position are controlled and used. Ultrasonic flaw detection method for transverse wave oblique angles, in which scanning is performed by selectively performing a transducer group that performs 2. An array probe having a plurality of transducers attached to a shoe for setting an angle of inclination, and a delay for setting a drive timing of a transducer to be driven among the transducers in the array probe. The setter, an ultrasonic flaw detector that drives the transducer based on the amount of delay set by the delay setter to transmit and receive to the transducer, and a waveform signal from the transducer that detected the reflected wave An ultrasonic array flaw detector for transverse wave oblique angles, which comprises a signal processor for processing and processing the data, and a data recorder for storing and displaying the signal as necessary. 3. The ultrasonic array flaw detection method for transverse wave oblique angles according to claim 1, wherein the shoe is made of acrylic, and the array-type flaw detection device used in this flaw detection method.