JP2009069077A - Device for inspecting pipe welded section - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for inspecting a pipe welded portion capable of improving detection precision of a defect. <P>SOLUTION: The device for inspecting the welded portion 2 of a pipe 1 includes an ultrasonic wave oblique probe 6 located in the outer circumference side of the pipe 1 and for transmitting ultrasonic waves towards the inner circumference side of the pipe 1 at an inclined angle and receiving reflected waved thereof; a flaw detection information storage 19 of a central control unit 10 for recording flaw detection information containing location information of the ultrasonic wave oblique probe 6 and waveform information of the reflected waves received by the ultrasonic wave oblique probe 6; and a display device 11 for converting reflected waves to reflection locations on a cross section in the plate-thickness direction of the pipe 1 based on the flaw detection information recorded in the flaw detection information storage 19, calculating and specifying the border line 28 of the welded portion 2 based on the locations of a plurality of reflected images 26a corresponding to the border of the welded portion 2, and determining a reflected image 26c at a location, which is located nearer to the pipe base material side than the border line 28 of this welded portion 2 and separated a prescribed threshold value or greater from the border line 28 of the welded portion 2, that is equivalent to a defect and then identifying to display it. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pipe welded portion inspection apparatus that inspects a welded portion of a pipe by ultrasonic inspection.

  For example, during in-service inspection of butt welds in nuclear power plant PLR (Primary Loop Recirculation System) pipes, etc., welds from the outer circumference side of the pipes (in detail, weld metal and heat affected zone) ) Must be inspected for defects. Conventionally, an ultrasonic flaw detector for inspecting the welded part of such a pipe has been disclosed (for example, see Patent Document 1).

  An ultrasonic flaw detector described in Patent Literature 1 is disposed on the outer peripheral side of a pipe, and transmits an ultrasonic wave at an angle inclined toward the inner peripheral side of the pipe and receives the reflected wave thereof. A scanner that moves the ultrasonic oblique probe in the axial direction and the circumferential direction of the pipe, and the position of the ultrasonic oblique probe is controlled via the scanner and the ultrasonic oblique probe is used. Controls the transmission of ultrasonic waves, automatically records the position information of the ultrasonic oblique angle probe and the reflected wave waveform information received by the ultrasonic oblique angle probe, on the plane development view and the plate thickness direction sectional view It has a control, recording, and processing device that displays reflected waves as an image. For example, when a reflected wave image corresponding to a defect is displayed and a defect is present, the control / recording / processing device displays the degree of the defect according to the intensity of the reflected wave.

JP 2007-471116 A

However, there are the following problems in the above-described prior art.
That is, although not clearly described in Patent Document 1, the control / recording / processing apparatus includes a reflected wave image and a design drawing (specifically, a design boundary line of a welded portion, etc.) in a cross section in the plate thickness direction. The images are displayed in a superimposed manner, and the presence or absence of defects is determined by visual judgment of the operator. However, when the outer periphery of the pipe is usually smoothed by a grinder or the like and the boundary between the weld and the pipe base material cannot be specified, the position of the weld cannot be accurately grasped. It was difficult to match the positional relationship accurately. In addition, for example, when the pipe base material and the weld metal are formed of austenitic stainless steel or nickel-base alloy, a reflected wave reflected at the boundary of the welded portion or the like is obtained. Therefore, it has not been possible to accurately determine whether the reflected wave image displayed in the vicinity of the boundary of the welded portion in the cross section in the plate thickness direction corresponds to the boundary of the welded portion or to the defect. Therefore, there is room for improvement in terms of defect detection accuracy.

  An object of the present invention is to provide a pipe welded portion inspection apparatus that can improve the detection accuracy of defects.

  In order to achieve the above object, the present invention provides an apparatus for inspecting a welded portion of a pipe by ultrasonic inspection, and is arranged on the outer peripheral side of the pipe and is inclined toward the inner peripheral side of the pipe. An ultrasonic probe that transmits ultrasonic waves at an angle and receives reflected waves thereof, and flaw detection information including positional information of the ultrasonic probes and waveform information of reflected waves received by the ultrasonic probes. Flaw detection information storage means for recording, reflected wave image display means for converting the reflected wave into a reflection position of the cross section in the plate thickness direction of the pipe based on the flaw detection information recorded by the flaw detection information storage means, and the reflection Boundary line setting means for calculating and setting the boundary lines of the welds based on the positions of a plurality of reflected wave images corresponding to the boundaries of the welds displayed by the wave image display means, and displayed by the reflected wave image display means Multiple reflected wave images Among them, the one located on the pipe base material side from the boundary line of the welded portion set by the boundary line calculation means and the position away from the boundary line of the welded portion by a predetermined threshold or more corresponds to a defect. Then, defect determination means for determining and identifying and displaying is provided.

  In the present invention, since the boundary line setting means calculates and sets the boundary line of the welded part based on the position of the reflected wave image corresponding to the boundary of the welded part, the boundary line of the welded part can be accurately specified. it can. Further, the defect determining means determines the presence or absence of a reflected wave image corresponding to the defect with reference to the set boundary line of the welded portion, and for example, if there is a reflected wave image corresponding to the defect, displays it. Therefore, in this invention, compared with the case where the presence or absence of a defect is determined, for example by an operator's visual judgment, the detection accuracy of a defect can be improved.

  According to the present invention, it is possible to improve the detection accuracy of defects.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram illustrating the overall configuration of the pipe welded portion inspection apparatus according to the present embodiment. FIG. 2 is a pipe cross-sectional view showing the ultrasonic oblique angle probe together with the welded part of the pipe.

  In these FIG.1 and FIG.2, the pipe welding part test | inspection apparatus aims at the test | inspection of the welding part 2 of the piping 1 (especially detection of the crack 4 which generate | occur | produces from the internal peripheral surface of the piping base material 3), A guide rail 5 attached to the outer peripheral side of the pipe 1, and a probe moving device 7 provided with an ultrasonic oblique angle probe 6 provided so as to be movable in the circumferential direction of the pipe 1 via the guide rail 5. The probe movement control device 7 is driven and controlled to control the position of the ultrasonic oblique angle probe 6, and the transmission of ultrasonic waves by the ultrasonic oblique angle probe 6 and The ultrasonic flaw detection control device 9 that controls the reception of the reflected wave, the probe position control device 8 and the ultrasonic flaw detection control device 9 are controlled in cooperation with each other, and flaw detection information (in detail, an ultrasonic oblique angle). Includes position information of the probe 3 and waveform information of the reflected wave received by the ultrasonic oblique angle probe 3 , A display device 11 for displaying an image by converting a reflected wave into a reflection position of a cross section in the thickness direction of the pipe 1 based on the flaw detection information recorded in the central control apparatus 10, and the pipe 1 And a design data storage device 12 for storing design data including a design boundary line of the welded portion 2 (a groove line of the piping base material 3).

  The probe moving device 7 includes the ultrasonic oblique probe 6 and an arm that extends in the axial direction of the pipe 1 (left and right in FIGS. 1 and 2) and supports the ultrasonic oblique probe 3. 13, a plurality of wheels 14 that support the arm 13 so as to be movable in the axial direction of the pipe 1, and the arm 13 (in other words, the ultrasonic oblique probe 6) is connected to the pipe 1 by controlling the rotation of the wheels 14. An axial movement control mechanism 15 for moving the axial direction of the apparatus, a gear 16 meshing with the guide rail 5, and rotation of the gear 16 to control the apparatus main body (in other words, the ultrasonic oblique probe 6) of the pipe 1. A circumferential movement control mechanism 17 that moves in the circumferential direction is provided. The guide rail 5 has a divided structure so that it can be attached to the outer peripheral side of the pipe 1.

  The ultrasonic oblique angle probe 6 transmits ultrasonic waves at an angle inclined toward the inner peripheral side of the pipe 1, and at the boundary of the welded part 2 of the pipe 1 (in detail, the weld metal and the pipe base material 3 So as to receive the reflected wave reflected at the boundary between and the weld metal sag and the reflected wave reflected by defects such as cracks 4 generated from the inner peripheral surface of the pipe preform 2. (The ultrasonic path is indicated by a dotted arrow in FIG. 2).

  Ultrasound is reflected at a portion where there is a difference in acoustic impedance (= medium density × sound velocity), and the reflection efficiency increases as the difference in acoustic impedance increases. For example, the weld 2 and the pipe base material 3 formed of austenitic stainless steel have almost no density difference. However, in the pipe base material 3, the direction of the crystal structure is random, so that the sound speed is constant regardless of the propagation direction of the ultrasonic wave, whereas in the welded portion 2, the direction of the crystal structure is aligned, so Has anisotropy. And as shown in FIG. 3, when the incident angle of the ultrasonic wave with respect to the direction of the columnar crystal structure of the welded portion 2 is 0 degree, 45 degrees, and 90 degrees, the sound velocity between the welded part 2 and the pipe base material 3 is obtained. The ratio is increased (in particular, the transverse wave is larger than the longitudinal wave), and the reflection efficiency at the boundary of the welded portion 2 is increased. Also, as shown in FIG. 4, the generation direction of the columnar crystal structure of the welded portion 2 is a normal direction on the boundary. Therefore, when the incident angle of the ultrasonic wave with respect to the boundary line of the welded portion 2 is 45 degrees, Increases efficiency. Moreover, the boundary line of the welding part 2 has the inclination part of the range of 0 degree-25 degree | times with respect to the plate | board thickness direction of the piping 1, for example. From the above, it is preferable that the ultrasonic oblique angle probe 6 transmits a transverse ultrasonic wave and sets the refraction angle θ in a range of 45 degrees to 70 degrees.

  The central controller 10 includes a trigger signal generator 18 that outputs a trigger signal to the probe position controller 8 and the ultrasonic flaw detector 9 and a flaw information storage 19 that records flaw information.

  The probe position controller 8 repeats scanning in the axial direction by changing a preset scanning pattern (for example, changing the circumferential position of the pipe 1 in response to the trigger signal from the trigger signal generator 18 of the central controller 10. Is calculated based on the rectangular scanning pattern), and the generated drive control signal (a signal corresponding to a predetermined movement amount) is sent to the axial movement control mechanism 15 and the circumferential movement control mechanism 17 of the probe moving device 7. The scanning control circuit 20 to output and the movement for calculating the position and position of the ultrasonic oblique probe 6 by calculating the moving direction and moving amount of the ultrasonic oblique probe 6 based on the control information of the scanning control circuit 20 The position information of the amount calculation circuit 21 and the ultrasonic oblique angle probe 6 calculated by the movement amount calculation circuit 21 is converted from an analog signal to a digital signal and output to the flaw detection information storage unit 19 of the central controller 10. A / D change And a circuit 22.

  The ultrasonic flaw detection control device 9 includes a transmission circuit 23 that transmits an ultrasonic wave transmission command to the ultrasonic oblique angle probe 6 in response to a trigger signal from the trigger signal generation unit 18 of the central control device 10, and an ultrasonic oblique signal. A receiving circuit 24 that receives the reflected wave received by the angular probe 6, and converts the waveform information of the reflected wave received by the receiving circuit 24 from an analog signal to a digital signal, so that the flaw detection information storage unit of the central controller 10 19 is provided with an A / D conversion circuit 25 that outputs to A / D converter 19.

  The flaw detection information storage unit 19 of the central control device 10 receives position information of the ultrasonic oblique angle probe 6 from the probe position control device 8 and waveform information of reflected waves from the ultrasonic flaw detection control device 9. These are recorded as flaw detection information, and a trigger signal transmission command is output to the trigger signal generator 18. The trigger signal generator 18 outputs a trigger signal in response to a trigger signal transmission command, and controls the probe moving device 8 and the ultrasonic flaw detection control device in cooperation with each other. In this way, flaw detection information is automatically recorded while the ultrasonic oblique angle probe 6 is scanned on the pipe 1.

  Here, as a major feature of the present embodiment, the flaw detection information storage unit 19 of the central controller 10 stores flaw detection information related to the reflected wave reflected at the boundary of the welded portion 2 of the pipe 1. Then, the display device 11 converts the reflected wave into the reflection position of the cross section in the plate thickness direction of the pipe 1 based on the plurality of flaw detection information recorded in the flaw detection information storage unit 19 of the central control device 10, and displays these images. The boundary line of the welded part 2 is calculated and set based on the positions of the plurality of reflected wave images corresponding to the boundary of the welded part 2 of the pipe 1, and the boundary line of the welded part 2 is superimposed and displayed. Also, the presence or absence of a reflected wave image corresponding to a defect is determined with reference to the boundary line of the welded portion 2, and for example, if there is a reflected image corresponding to a defect, it is identified and displayed. The control procedure of the display device 11 will be described with reference to FIG.

  FIG. 5 is a flowchart showing the contents of control processing of the display device 11.

  In FIG. 5, first, in step 100, the display device 11 reads a plurality of flaw detection information recorded in the flaw detection information storage unit 19 of the central control device 10, and the amplitude is preset in order to remove electrical noise. Extract reflected waves above the threshold. Thereafter, the process proceeds to step 110 where the extracted reflected wave is converted into the position of the cross section in the plate thickness direction of the pipe 1 and displayed as an image (specifically, an image representing the amplitude of the reflected wave with contour lines). Specifically, as shown in FIG. 6, the position of the ultrasonic oblique probe 6 in the axial direction of the pipe 1 is taken as the X axis, and the ultrasonic beam path (specifically, until the ultrasonic wave is reflected and returned). The one-way propagation time is expressed in distance) as the Y axis, and the reflected wave is transmitted in the thickness direction of the pipe 1 using an oblique coordinate system in which the Y axis is inclined by the ultrasonic refraction angle θ. Convert to cross-sectional position. In this embodiment, the operator attaches a virtual center line 27 (see FIGS. 1 and 2 described above) of the welded portion 2 to the outer peripheral surface of the pipe 1 with a pen or the like. By matching the initial position of the acoustic angle probe 6, the position (reference position) of the virtual center line 27 is set as the coordinate origin O. For example, as shown in FIG. 6, a plurality of reflected wave images 26 a corresponding to the boundary between the weld metal and the pipe base material 3, a reflected wave image 26 b corresponding to the inner peripheral surface of the sag of the weld metal, and the pipe A reflected wave image 26c corresponding to the corner of the crack 4 generated from the inner peripheral surface of the base material 3 is displayed.

  In step 120, the display device 11 reads the design boundary line of the welded portion 2 stored in the design data storage device 12 (or may be extracted from the design drawing), and the reflected wave images 26a and 26b described above. , 26c, the position of the design boundary line is calculated. As a specific example, the reflected wave images 26a whose position intervals are equal to or less than the threshold are extracted as those corresponding to the boundary of the welded portion 2, the positions of these reflected wave images 26a are linearly approximated, and the design boundary line is defined as X The position where the correlation is highest is calculated by moving in the axial direction. As a method for obtaining the correlation, there are a maximum likelihood method and a least square method. In this way, the boundary line 28 of the welded portion 2 is set and displayed superimposed on the above-described reflection images 26a to 26c (see FIG. 6).

  Then, the process proceeds to step 130, for example, an inspection range 29 (for example, a boundary, for example) that is set on the pipe base material side (right side in FIG. 6) from the boundary line 28 of the welded portion 2 and includes the inner peripheral surface of the pipe base material. In the range of 10 mm in the axial direction of the pipe 1 from the center position 28a of the line 28), it is determined whether or not there is a reflected wave image separated from the boundary line 28 by a predetermined threshold or more. Then, for example, as shown in FIG. 6, when there is a reflection image 26 c that is separated from the boundary line 28 by a predetermined threshold or more in the inspection range 29, the determination in step 130 is satisfied and the process proceeds to step 140, and the reflection image 26 c Is identified and displayed by color or the like.

  In the above description, the flaw detection information storage unit 19 of the central controller 10 includes flaw detection information including the position information of the ultrasonic probe described in the claims and the waveform information of the reflected wave received by the ultrasonic probe. The flaw detection information storage means to record is comprised. Step 110 performed by the display device 11 constitutes reflected wave image display means for displaying the image by converting the reflected wave into the reflection position of the cross section in the plate thickness direction of the pipe based on the flaw detection information recorded in the flaw detection information storage means. The step 120 performed by the display device 11 is a boundary line setting means for calculating and setting the boundary line of the welded portion based on the positions of a plurality of reflected wave images displayed on the reflected wave image display means and corresponding to the boundary of the welded portion. Configure. Steps 130 and 140 performed by the display device 11 are positioned closer to the pipe base material than the boundary line of the welded portion set by the boundary line calculation means among the plurality of reflected wave images displayed by the reflected wave image display means. In addition, a defect determination unit is configured to identify and display a position at a position separated from the boundary of the weld by a predetermined threshold or more as being equivalent to a defect. Further, the ultrasonic oblique angle probe 6, the probe moving device 7, and the probe position control device 8 constitute an input unit that can input a reference position attached to the outer peripheral surface of the pipe 1.

  In the present embodiment configured as described above, the display device 11 calculates and sets the boundary line of the welded part 2 based on the reflected wave image 26a corresponding to the boundary of the welded part 2 of the pipe 1 and so on. The boundary line of the weld 2 can be accurately specified. Also, the presence or absence of a reflected wave image corresponding to a defect is determined with reference to the set boundary line of the welded portion 2, and for example, if there is a reflected wave image 26c corresponding to a defect, it is identified and displayed. Therefore, compared with the case where the presence or absence of a defect is determined, for example by visual judgment of an operator, the defect detection accuracy can be improved.

  In the above embodiment, the display device 11 calculates and sets the position of the design boundary line of the welded part 2 based on the correlation with the positions of the plurality of reflected wave images 26a and the like as the boundary line setting function. However, the present invention is not limited to this. That is, for example, a reflected wave image 26a in which the mutual position interval is equal to or smaller than a threshold value is extracted as corresponding to the boundary of the welded portion 2, and a regression line (boundary line of the welded portion 2) ) May be calculated and set. In such a case, the same effect as described above can be obtained.

  In the above-described embodiment, the ultrasonic oblique angle probe 3 is used as an ultrasonic probe that transmits ultrasonic waves at an angle inclined toward the inner peripheral side of the pipe 1 and receives the reflected waves. Although the case where it is provided has been described as an example, it is not limited thereto. That is, instead of the ultrasonic oblique angle probe 3, for example, an ultrasonic array sensor may be provided. Such a modification will be described below.

  FIG. 7 is a schematic diagram illustrating the configuration of the ultrasonic array sensor according to the first modification. In the first modification, the description and illustration of the parts equivalent to those of the above embodiment will be omitted as appropriate.

  In the first modification, the arm 13 of the probe moving device 7 is provided with an ultrasonic array sensor 31 having a plurality of (eight in FIG. 7) transducers 30 arranged in the axial direction of the pipe 1. It has been. Further, a vibrator control device 33 (vibrator control means) for controlling the transmission and phase of the spherical ultrasonic waves 32 from the plurality of vibrators 31 is provided. The vibrator control device 33 controls the superposition position of the phases of the spherical ultrasonic waves 32 generated from the vibrator 31 by controlling the voltage application time (in other words, the delay time) to each of the plurality of vibrators 31. Thus, the angle and focusing of the interference wave 34 are variably controlled. As a result, the interference wave 34 is transmitted at an arbitrary focusing target point P (preferably the inner peripheral surface of the pipe base material) and at an arbitrary inclination angle θ.

  Also in the first modified example configured as described above, the defect detection accuracy can be increased as in the above-described embodiment.

  FIG. 8 is a pipe cross-sectional view showing the ultrasonic array sensor according to the second modified example together with the welded part of the pipe. Note that in this second modification, the description of the same parts as in the above embodiment will be omitted as appropriate.

  In the second modification, an ultrasonic array sensor 31A having a large number (20 or more in FIG. 8) of transducers 30 arranged in the axial direction of the pipe 1, and transmission of spherical ultrasonic waves 32 from the transducers 30. And a vibrator control device 33A (vibrator control means, not shown) for controlling the phase respectively. The vibrator control device 33A selects, for example, eight vibrators 30 adjacent to each other among the many vibrators 30, and controls the voltage application time (in other words, delay time) to the selected vibrators 31, respectively. By controlling the superposition position of the phase of the spherical ultrasonic wave 32 generated from the transducer 31, the angle and focusing of the interference wave 34 are variably controlled. Thereby, the interference wave 34 is transmitted at an arbitrary focusing target point (preferably the inner peripheral surface of the pipe base material) and at an arbitrary inclination angle.

  In addition, the vibrator control device 33A appropriately selects eight vibrators 30 to which a voltage is applied in order to move the incident position of the interference wave 34 in the axial direction of the pipe 1 (note that the vibrator 31). The voltage application time pattern, in other words, the delay time pattern is constant). Note that the ultrasonic array sensor 31A is moved in the circumferential direction of the pipe 1 by a circumferential movement control mechanism (not shown).

  Also in the second modified example configured as described above, the detection accuracy of defects can be increased as in the above-described embodiment. In the second modification, the transducer control device 33A moves the incident position of the interference wave 34 by appropriately selecting the transducer 31 to which the voltage is applied. Thereby, compared with the case where the arm 13, the wheel 14, and the axial movement mechanism 15 are provided and the ultrasonic probe is mechanically moved as in the above-described embodiment, the scanning speed in the axial direction of the pipe 1 is increased. Can be increased. Therefore, the inspection time can be shortened.

  In the above description, the case where the welded portion 2 and the pipe base material 3 are formed of austenitic stainless steel has been described as an example. However, the present invention is not limited thereto, and may be formed of, for example, a nickel-based alloy. In this case, the same effect as described above can be obtained.

It is the schematic showing the whole structure of one Embodiment of the piping welding part test | inspection apparatus of this invention. It is a piping sectional view showing the ultrasonic oblique angle probe which constitutes one embodiment of the piping welding part inspection device of the present invention with the welding part of piping. It is a characteristic view for demonstrating the sonic anisotropy in the welding part of piping. It is piping sectional drawing for demonstrating the columnar crystal structure in the welding part of piping. It is a flowchart showing the control processing content of the display apparatus which comprises one Embodiment of the piping welding part test | inspection apparatus of this invention. It is a figure showing the image of the reflected wave processed with the display apparatus which comprises one Embodiment of the piping welding part inspection apparatus of this invention, and the boundary line of a welding part as an example. It is the schematic showing the structure of the ultrasonic array sensor which comprises the 1st modification of the pipe welding part test | inspection apparatus of this invention. It is a piping sectional view showing the ultrasonic array sensor which constitutes the 2nd modification of the piping welding part inspection device of the present invention with the welding part of piping.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piping 2 Welding part 3 Piping base material 4 Crack 6 Ultrasonic oblique angle probe 11 Display apparatus 12 Design data memory | storage device 19 Flaw detection information memory | storage part 26a Reflected wave image 26b Reflected wave image 26c Reflected wave image 28 Boundary line 30 Vibrator 31 Ultrasonic Array Sensor 31A Ultrasonic Array Sensor 32 Spherical Ultrasound 33 Transducer Controller 33A Transducer Controller

Claims (5)

In pipe weld inspection equipment that inspects pipe welds by ultrasonic inspection,
An ultrasonic probe that is disposed on the outer peripheral side of the pipe and transmits an ultrasonic wave at an angle inclined toward the inner peripheral side of the pipe and receives the reflected wave;
Flaw detection information storage means for recording flaw detection information including position information of the ultrasonic probe and waveform information of reflected waves received by the ultrasonic probe;
Reflected wave image display means for converting the reflected wave into the reflection position of the cross section in the plate thickness direction of the pipe based on the flaw detection information recorded in the flaw detection information storage means, and displaying the image.
Boundary line setting means for calculating and setting the boundary line of the welded part based on the position of a plurality of reflected wave images displayed on the reflected wave image display means and corresponding to the boundary of the welded part;
Among the plurality of reflected wave images displayed by the reflected wave image display means, the pipe is located on the pipe base material side from the boundary line of the welded portion set by the boundary line calculating means, and in advance from the boundary line of the welded portion. A pipe welded part inspection apparatus comprising: defect determination means for determining that a position at a distance apart from a set threshold or more is equivalent to a defect and displaying the defect.   2. The pipe welded portion inspection apparatus according to claim 1, further comprising design boundary line storage means for storing a design boundary line of the welded portion, wherein the boundary line setting means includes a plurality of pieces displayed by the reflected wave image display means. An apparatus for inspecting a welded part of a pipe, wherein the position of a design boundary line of the welded part is calculated and set based on a correlation with a position of a reflected wave image.   2. The pipe welded portion inspection apparatus according to claim 1, further comprising an input unit capable of inputting a reference position attached to an outer peripheral surface of the pipe, wherein the reflected wave image display unit displays the reference position input by the input unit. An apparatus for inspecting a welded portion of a pipe, wherein a reflected wave image is displayed as a coordinate origin.   2. The pipe welded portion inspection apparatus according to claim 1, wherein the ultrasonic probe is an ultrasonic array sensor having a plurality of vibrators arranged in an axial direction of the pipe, A pipe welded portion inspection apparatus comprising vibrator control means for controlling the transmission and phase of spherical ultrasonic waves.   2. The pipe weld inspection apparatus according to claim 1, wherein the pipe base material and the weld metal are made of austenitic stainless steel or a nickel base alloy.

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