JP2002148243A - Ultrasonic flaw detecting device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic flaw detecting device capable of substantially improving efficiency and accuracy in scanning including accompanying work and satisfactorily holding detection sensitivity. SOLUTION: A processing device converts scanning distances different according to the size of a rotor of which flaws are to be detected into radians on the basis of detection signals from a sensor for detecting a zero point provided for first and second probe holders. Then data processing is performed on the detection signals from an ultrasonic probe held by the first and second probe holders, and the results are displayed on a display device. By this, it is possible to easily set the zero point of flaw detection data regardless of the size of the rotor of which flaws are to be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic flaw detector and method for inspecting defects such as cracks generated in a blade implant of a rotor wheel of a steam turbine.

[0002]

2. Description of the Related Art In a steam turbine, a strong centrifugal force acts upon the rotation of the rotor during turbine operation, so that excessive stress and vibration are generated at the blade implant portion where the rotor wheel blade is implanted. Cracks may occur. For this reason, the blade implanted portion of the rotor wheel is subjected to a nondestructive inspection method, particularly an ultrasonic inspection method, in a periodic inspection. In this inspection, the scanning of the ultrasonic probe is performed over the entire circumference of the rotor wheel on which the blade is mounted.

FIG. 10 is a perspective view showing an example of a rotor taken out of a turbine casing for inspection. Rotor 1
, A large number of blades 3 are mounted on each rotor wheel 2 in an annular row. The mounting portion is the blade implanting portion 5. The rotor wheel 2 on which one row of blades 3 is implanted and the rotor wheel 2 on which the other row of blades 3 are implanted approach each other, and the inspection by the ultrasonic probe is performed by using the ultrasonic probe for the rotor wheel 2. Perform by contacting the surface. Therefore, the scanning by the ultrasonic probe is hindered by the blades 3 and cannot be performed as expected.

FIG. 11 is a partially cutaway perspective view of a rotor showing an operation of operating an ultrasonic probe by scanning the entire circumference for ultrasonic inspection of the rotor wheel 2. The ultrasonic probe 4 is placed on one side of the rotor wheel 2, from which an ultrasonic beam U is applied to the blade implant 5 of the rotor wheel 2.
Incident toward. This ultrasonic beam U is shown in FIG.
(A) As shown in (b), the blade reaches the blade implantation part 5,
If there is an axial crack 6 there, the ultrasonic beam U is reflected by the axial crack 6, and the reflected wave reaches the ultrasonic probe 4 which has emitted the ultrasonic beam U, Detected as a defect. This scanning is performed over the entire circumference of the rotor wheel 2 and is carried out on the opposite side in a manner similar to the scanning on one side.

When a reflected echo is detected, a transmitting ultrasonic probe 4a and a receiving ultrasonic probe 4b are arranged as shown in FIG. 13 for more detailed inspection. And scan again over the entire circumference. FIG. 14A shows an ultrasonic beam U emitted from the transmitting ultrasonic probe 4a.
As shown in (b), the light reaches the blade implantation part 5, is reflected by the crack 6 in the axial direction, and is detected as a defect when the reflected wave U 'reaches the receiving ultrasonic probe 4b. This method is called a pitch catch method, and can detect internal defects with high sensitivity.

[0006]

However, what is problematic when performing the above-mentioned inspection in an automated manner is control of the flaw detection position. That is, when an indication echo is detected by flaw detection, it is necessary to specify its position, and accurate position control in flaw detection is an issue.

Further, the size of the turbine rotor to be inspected,
Since the shapes are different from each other, and the number of blades differs depending on the paragraph, in order to know the flaw detection position accurately, it must be possible to set it to indicate the exact flaw detection position taking into account those differences. Must.

In the conventional method, the effective beam path is limited to the vicinity of the first hook portion of the blade implantation portion 5 calculated. For this reason, the echo that appears outside the beam path is currently ignored, and the blade implant 5
A wound echo detected by reflecting inside may be overlooked.

Conventionally, it is difficult to discriminate whether the detected indication echo is due to rust, pitting, or a crack, and the evaluation of the size when the crack is a defect is based on the experience of the inspector. However, it is large and difficult. In addition, since the A-scope is used for the evaluation of the inspection and only the peak value of the waveform is evaluated, the judgment is influenced by the skill of the inspector, and the record is left only in a numerical value, so that it is difficult to see visually.

[0010] Ultrasonic flaw detection of the rotor wheel 2 requires, for example, inspection of all three or four rotors 1 during the periodic inspection of the steam turbine. In some cases, all inspections cannot be performed during a limited time, ie, medium time. Therefore, it is demanded that work be efficiently performed without wasting time in scanning.

An object of the present invention is to provide an ultrasonic flaw detection apparatus and method capable of remarkably improving the efficiency and accuracy in scanning, including incidental operations, and maintaining good detection sensitivity.

[0012]

According to a first aspect of the present invention, there is provided an ultrasonic flaw detector which opposes both sides of a rotor wheel of a rotor with the rotor wheel interposed therebetween and extends circumferentially along an outer peripheral portion of the rotor. First and second probe holders that are movably provided, and two defects that are provided in the first and second probe holders and detect a defect occurring in a blade implant portion of the rotor wheel. Ultrasonic probe
The first and second probe holders are provided so as to tie both the first and second probe holders at positions beyond the blades of the rotor wheel, and the first and second probe holders are provided on both side surfaces of the rotor wheel. A link mechanism for operating the first and second probe holders in conjunction with each other, and a zero point detection sensor for detecting a reflector attached to a blade of the turbine wheel that is to be a zero point. A processing device that converts a scanning distance that differs depending on the size of a flaw detection target rotor into radians based on a detection signal from the zero point detection sensor and that performs data processing on a detection signal from the ultrasonic probe; and A display device for displaying a result processed by the device.

[0013] In the ultrasonic flaw detector according to the first aspect of the present invention, before the ultrasonic flaw detection is performed, the processing device may detect the zero point detection sensor provided on the first or second probe holder. A scanning distance that varies depending on the size of the flaw detection target rotor is converted to radians based on the detection signal. Then, the detection signal from the ultrasonic probe held by the first and second probe holders is subjected to data processing, and the result is displayed on the display device. This makes it easy to set the zero point of the flaw detection data regardless of the size of the rotor to be flaw-detected.

According to a second aspect of the present invention, in the ultrasonic flaw detector according to the first aspect, the processing device performs data processing for displaying flaw detection data obtained from the ultrasonic probe on a B scope. After that, the number of blade groups of the paragraph examined in advance, the number of blades in each group, and the number of blades to which the reflecting plate for detecting the zero point is attached are 360 degrees with the total number of blades based on the number of the group and the number of the group. Equally dividing and calculating the group boundary position of the blade and the boundary position of the blade, wherein the display device displays the flaw detection data in association with the group boundary position of the blade and the boundary position of the blade. .

In the ultrasonic flaw detector according to the second aspect of the invention, in addition to the operation of the first aspect of the invention, data processing for displaying flaw detection data obtained from each ultrasonic probe on a B scope is performed. After that, the number of blade groups in the paragraph examined in advance, the number of blades in each group, and the number of blades in the group to which the reflector for zero point detection is attached, the group boundaries of the blades and the boundaries of the blades, respectively. indicate. B of inspection result
Since the lines of the group boundary and the blade boundary are displayed on the scope, when an indication echo is detected, it is possible to easily evaluate which paragraph is located at which position.

In the ultrasonic flaw detector according to a third aspect of the present invention, in the first aspect of the present invention, the processing apparatus may further include a peak of a pointing echo on both B scopes of the ultrasonic probe facing each other across the rotor wheel. The size of the crack-like defect is evaluated based on the position.

In the ultrasonic flaw detector according to a third aspect of the present invention, in addition to the operation of the first aspect of the invention, data processing for displaying flaw detection data obtained from each ultrasonic probe on a B scope is performed. The size of the crack-like defect is evaluated by examining the peak position of the pointing echo in the B scope of the ultrasonic probe facing the rotor wheel. When a crack defect is detected, it can be easily determined whether or not there is a size that penetrates the first hook portion in evaluating the size.

According to a fourth aspect of the present invention, in the ultrasonic inspection apparatus according to the first aspect of the present invention, the processing apparatus includes a data processing for displaying inspection data obtained from each of the ultrasonic probes on a B scope. After setting the effective flaw detection range, a circular graph having the maximum value at each scanning position as a radius is created and displayed on the display device.

In the ultrasonic flaw detector according to a fourth aspect of the present invention, in addition to the operation of the first aspect of the present invention, data processing for displaying flaw detection data obtained from the ultrasonic probe on a B scope is performed. After setting the flaw detection range, the maximum value at each scanning position is displayed on a circular graph. This allows
The display is such that the position of the inspection paragraph in which the defect is present can be understood.

According to a fifth aspect of the present invention, in the ultrasonic flaw detection method, the first and second probe holders are arranged on both sides of the rotor wheel of the rotor so as to face each other with the rotor wheel interposed therebetween. Two ultrasonic probes are provided in each of the first and second probe holders, and the first and second probe holders are moved along the outer peripheral portion of the rotor by rotation of the rotor. In the ultrasonic flaw detection method in which the ultrasonic probe detects a defect generated in the blade implant portion of the rotor wheel by the ultrasonic probe, a reflector is attached to a blade of the turbine wheel which is to be set to a zero point. A zero point detection sensor for detecting the reflection plate is provided on the first or second probe holder, and the rotor is rotated so that the second detection from the first detection of the reflection plate by the zero point detection sensor is performed. Times The traveling distance up to the detection of the reflector is determined, the scanning distance is converted into radians, and the flaw detection data from the ultrasonic probe is associated with the radian-converted traveling distance of one rotation of the rotor. And detecting it.

In the ultrasonic flaw detection method according to the fifth aspect of the present invention, the rotor is rotated, and the reflection plate is detected by the zero point detection sensor moving in the circumferential direction along the outer periphery of the rotor, and the first reflection plate is detected. The scanning distance from the detection of the reflection plate to the detection of the second reflection plate is obtained, the scanning distance is converted into radians, and the flaw detection data from the ultrasonic probe is converted to the radian-converted traveling distance of one rotation of the rotor. Detected in association.

[0022]

Embodiments of the present invention will be described below. FIG. 1 is an explanatory diagram of an ultrasonic flaw detector according to an embodiment of the present invention.

In FIG. 1, the ultrasonic flaw detector is a rotor 1
Probe holders 1 arranged on both sides of the rotor wheel 2 so as to face each other with the rotor wheel 2 interposed therebetween
1a and a second probe holder 11b. The first probe holder 11a is in contact with one surface of the rotor wheel 2 to detect two ultrasonic probes 12a,
12b, and the two ultrasonic probes 12a and 12b
Has a zero point detection sensor 27 at the center.

Further, the two ultrasonic probes 12a,
A brush 13 and a spatula 14 are provided in combination with 12b. The brush 13 applies a couplant to the surface of the rotor wheel 2 to be flaw-detected, and the spatula 14 removes the couplant from the surface of the rotor wheel 2 after flaw detection by the ultrasonic probes 12a and 12b.

That is, the brush 13 and the spatula 14 are arranged on the same circumference as the two ultrasonic probes,
Are located at the top of the two ultrasonic probes 12a and 12b,
The spatula 14 is at the tail and is configured such that the brush 13 applies the couplant first and the spatula 14 later wipes it off.

The first and second probe holders 11
a and 11b are connected to each other by a link mechanism 15 to synchronize their movements during scanning by the ultrasonic probes 12a and 12b on both surfaces of the rotor wheel 2. The link mechanism 15 moves the probe holders 11 at positions beyond the tips of the blades implanted in the rotor wheel 2.
a and 11b are connected.

Further, although not shown, the second probe holder 11b also has two ultrasonic probes 12c and 12d and the same circumference as the two ultrasonic probes 12c and 12d. Has a brush 13 and a spatula 14 arranged at the center. Also,
Blade 3 of blade 3 of turbine wheel 2 to be set to zero point
A reflector is attached to the sensor, and the zero point detection sensor 27
Is for detecting the reflection plate.

The processing device 7 receives the detection signal from the zero point detection sensor 27 and the detection signals from the ultrasonic probes 12a to 12d, and based on the detection signal from the zero point detection sensor 27, detects the rotor to be detected. Is converted to radians depending on the size of. Further, the detection signals from the ultrasonic probes 12a to 12d are subjected to data processing, and the flaw detection data is displayed on the display device 8 together with the detection positions converted into radians.

FIG. 2 is a front view of the vicinity of the first probe holder 11a of the ultrasonic flaw detector shown in FIG. This first
The probe holder 11a has two telescopic supporting legs 16a and 16b, each of which can be extended and contracted, a bridge member 17 connecting the two supporting legs 16a and 16b, and two ultrasonic probes. Arm 18 for holding the child 12a, 12b,
2 and 1 for holding the spatula 14 respectively
9 and 20. A zero point detection sensor 27 is provided on the blade side of the first probe holder 11a.

Each of the two support legs 16a, 16b is provided at its lower end with a roller 22, which is guided by the projection 21 of the rotor 1 and rotates while sliding on the surface of the rotor 1. Further, of the two holders 19 and 20, one of the holders 19 holding the brush 13 positioned at the head is a front support leg 16
a, while the other holder 20 holding the spatula 14 located at the rear tail is fixed to the rear support leg 16b.

Although not shown, the second probe holder 11b also includes two similar support legs, a bridge member, an arm, and two holders.

FIG. 3 is a side view of the first probe holder of the ultrasonic flaw detector shown in FIG. As shown in FIG. 3, a reflection plate 28 is provided on the blade 3 side, and a zero point detection sensor 27 for detecting the position of the reflection plate 28 is provided on the first contact holder 11a. When the first and second contact holders 11a and 11b are guided by the convex portion 21 of the rotor 1 and the surface of the rotor 1 is rotated by the roller 22, a zero point is detected every rotation.

The holder 1 is mounted on the support legs 16a and 16b.
The positions of 9 and 20 can be adjusted. By adjusting these positions, the contact state between the brush 13 (not shown) and the spatula 14 and the surface of the rotor wheel 2 can be kept constant.

In detecting a defect on the rotor wheel 2, first, a scanning distance which varies depending on the size of the rotor to be detected is converted into radians based on a detection signal from the zero point detection sensor 27.

FIG. 4 is a flowchart showing the operation in that case. First, the zero point detecting sensor 27 is mounted on the first probe holder 11a, and the reflecting plate 28 is attached to the vane 3 which becomes the zero point (Step 101). Next, the rotor 1 is rotated (step 102). When the reflection plate 28 is detected for the first time by the zero point detection sensor 27, the processing device 7 starts counting by the encoder (step 10).
3) The second reflection plate 2 by the zero point detection sensor 27
When 8 is detected, the counting of the encoder is stopped (step 104). Thereby, 36 of the rotor 1
0 degrees is set (step 105). As described above, the 360-degree scanning distance different for each rotor 1 is counted by the encoder, the 360-degree setting is performed, and the different scanning distance is converted into radians depending on the size of the rotor 1.

Here, the first probe holder 11a has two ultrasonic probes 12a and 12b, and the second probe holder 11b also has two ultrasonic probes. 12c, 12d
Which are in contact with the surface of the rotor wheel 2. These ultrasonic probes 12 a to 12 d emit an ultrasonic beam toward the blade implant 5 of the rotor wheel 2, and for example, cracks 6 in the blade implant 5.
Receives reflected waves from. Then, the processing device 7 performs data processing for displaying the flaw detection data obtained from the ultrasonic probe 12 on the B scope, and displays the flaw detection data on the display device 8 when the group boundary L1 of the blade 3 and the blade boundary. L
2 is also displayed. Here, the blades are formed by integrating several blades by a connecting member, and the number of blade groups refers to the number of blade groups in this case.

FIG. 5 is an explanatory diagram of a display example of flaw detection data displayed on the display device 8. FIG. 5 shows a flaw detection result by the B scope obtained by one ultrasonic probe 12a.

When displaying the group boundary L1 and the blade boundary L2 of the blade 3 together with the flaw detection data, the number of blade groups in the paragraph, the number of blades in each group, and the reflector 28 for zero point detection are checked in advance. The 360 ° is equally divided by the total number of blades based on the number of the group of the blades to which the affixed is attached, and the group boundary position and the boundary position of the blade 3 are calculated and displayed.

FIG. 6 is a flowchart showing the operation in the case where the group boundary position and the boundary position of the blades are displayed together with the flaw detection data by the B scope.

First, the number of blade groups in the paragraph, the number of blades in each group, and the number of the group of blades 3 serving as a zero point are input (step 111). Next, the entire circumference of 300 degrees is divided by the total number of blades input in step 111 to calculate an angle per blade (step 112). Further, with respect to the flaw detection data of the B scope displayed after the flaw detection, the group boundary L1 and the blade boundary L2 are displayed in different colors (step 113). A number indicating the number of the group is displayed beside the line indicating the group boundary L1. FIG. 5 shows the case of eight groups and nine groups.

By performing such a display, it is possible to easily know in which group of which position the detected detected echo is located.

The flaw detection data shown in FIG. 5 shows a B scope obtained as a result of flaw detection. However, the beam path range can be extended behind the conventional effective beam path range to make the beam path range wider. It is possible. That is, with respect to the beam path range which has been evaluated in the conventional inspection, the range is approximately doubled backward, and the delayed echo appearing from the rotor shape is also evaluated. This makes it possible to reliably detect the indication echo that was missed in the past,
Even small defects can be detected with high accuracy.

FIG. 7 is a flowchart showing a procedure for evaluating the size of a crack defect based on flaw detection data detected by the ultrasonic probe 12. First, it is confirmed whether or not the detected indication echo has a tail behind the beam path (step 121). If no indicating echo having a tail is confirmed, it is determined that the echo is due to rust or pitting (step 122).

On the other hand, when an indication echo having a tail behind the beam path is detected, both of the ultrasonic probes facing each other across the rotor wheel have a peak on the band-like echo indicating the first hook portion. It is determined whether or not there is (step 123).

If there is no peak on the band echo,
As shown in FIG. 8A, it is determined that the defect is a crack having a size that cannot reach the first hook portion of the blade implant portion (step 124). On the other hand, when there is a peak on the band-shaped echo, as shown in FIG. 8B, it is determined that there is a crack defect larger than the size penetrating the first hook portion of the blade implant portion (step 125). .

That is, in the confirmation in step 121, if an indication echo having a tail is confirmed, it indicates that a crack defect exists.
By referring to the scope and confirming whether there is an echo peak on the band-shaped indicating pattern indicating the first hook portion,
It is determined whether or not the crack is larger than the size penetrating the first hook portion.

When the peak of the echo is present on the band-shaped pointing pattern indicating the first hook portion on both of the ultrasonic probes located across the rotor wheel, the defect indicated by the pointing echo is the first. Assess that the hook is penetrated or larger.

On the other hand, one of the ultrasonic probes at the position sandwiching the rotor wheel has an echo peak on a band-shaped indicating pattern indicating the first hook portion, and the other indicates the first hook portion. When there is no peak of the echo on the band-shaped pointing pattern, it is evaluated that the defect indicated by the pointing echo does not reach the first hook penetration. In other words, the first probe is placed on both of the ultrasonic probes at the position sandwiching the rotor wheel.
This defect is smaller than the case where the peak of the echo is on the band-shaped indicating pattern indicating the hook portion.

As described above, the flaw detection data detected by the ultrasonic probes facing each other across the rotor wheel is displayed on the B scope, and the peak position of the pointing echo is examined to evaluate the size of the crack-like defect. Therefore, it can be easily determined whether or not there is a size that penetrates the first hook portion.

Next, when displaying the flaw detection data obtained from the ultrasonic probe 12 on the B scope, after setting the effective flaw detection range, the maximum value at each scanning position can be displayed on a circular graph. is there. FIG. 9 is an explanatory diagram in the case where flaw detection data is displayed in a circular graph, and FIG.
FIG. 9B is an explanatory diagram of a normal display mode of the scope, and FIG. 9B is an explanatory diagram of a display mode of a circular graph.

FIG. 9B shows the result of circularly displaying the flaw detection results. Fig. 9 shows the B scope obtained as a result of flaw detection.
(A), the effective beam path range (effective flaw detection range) H is determined, and the maximum value in the beam path is displayed as the radius of the circular graph. Thereby, it is possible to easily recognize at which position of the paragraph the pointing echo is detected.

[0052]

As described above, according to the present invention, the zero point vane can be detected by the zero point detecting sensor mounted on the probe holder. Settings can be made accurately. Further, by inputting the number of blades of the paragraph in advance, it is possible to know the group of the number of blades in the detected indication echo. Further, by displaying the flaw detection result in a circular shape, it is possible to easily recognize the position of the pointing echo in the paragraph.

Referring to the B scope obtained from the ultrasonic probe at the position sandwiching the rotor wheel, the peak position of the indicating echo indicating the crack defect is on the band-like echo indicating the first hook portion. By determining whether or not the size of the crack defect penetrates the first hook, it can be determined.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an ultrasonic flaw detector according to an embodiment of the present invention.

FIG. 2 is a front view of a first probe holder of the ultrasonic flaw detector shown in FIG. 1;

FIG. 3 is a side view of a first probe holder part of the ultrasonic flaw detector shown in FIG. 1;

FIG. 4 is a flowchart illustrating an operation when converting a scanning distance that differs depending on the size of a flaw detection target rotor into radians based on a detection signal from a zero point detection sensor according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram of a display example of flaw detection data displayed on the display device according to the embodiment of the present invention.

FIG. 6 is a flowchart showing an operation when the flaw detection data displayed on the display device according to the embodiment of the present invention is displayed together with the group boundary position and the boundary position of the blades.

FIG. 7 is a flowchart showing a procedure for evaluating the size of a crack defect in the embodiment of the present invention.

FIGS. 8A and 8B are explanatory diagrams of a defect of the blade implant portion, wherein FIG. 8A is an explanatory diagram of a crack defect having a size that does not allow the first hook portion of the blade implant portion to penetrate, and FIG. FIG. 4 is an explanatory view of a crack defect having a size equal to or larger than a size penetrating the first hook portion.

9A and 9B are explanatory diagrams of a case where flaw detection data is displayed in a circular graph in the embodiment of the present invention. FIG. 9A is an explanatory diagram of a normal display mode of a B scope, and FIG. 9B is a circular graph. Explanatory drawing of the display form of.

FIG. 10 is a perspective view showing an example of a conventional turbine rotor.

FIG. 11 is a partially cutaway perspective view of a rotor showing an example in which an ultrasonic probe is operated by full-circumference scanning for ultrasonic inspection of a conventional rotor wheel.

FIG. 12 is an explanatory diagram of the behavior of an ultrasonic beam in a conventional scanning method.

FIG. 13 is a partially cutaway perspective view of a rotor showing another example of operating a conventional ultrasonic probe by full-circumferential scanning for ultrasonic inspection of a rotor wheel.

FIG. 14 is an explanatory diagram of the behavior of an ultrasonic beam in another conventional scanning method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotor, 2 ... Rotor wheel, 3 ... Blade, 4 ... Ultrasonic probe, 5 ... Blade implantation part, 6 ... Crack, 7 ... Processing device, 8 ... Display device, 11 ... Probe holder, 12 ... Ultrasonic probe, 13 ... Brush, 14 ... Spatula, 15 ... Link mechanism, 16 ... Support leg, 17 ... Bridge material, 18 ... Arm,
19, 20: Holder, 21: Convex part, 22: Roller, 27
… Zero point detection sensor, 28… Reflector

Claims (5)

[Claims] 1. A first and second probe holders provided on both sides of a rotor wheel of a rotor so as to face each other with the rotor wheel interposed therebetween and to be movable in a circumferential direction along an outer peripheral portion of the rotor. An ultrasonic probe provided in each of the first and second probe holders for detecting a defect generated in a blade implant portion of the rotor wheel; and the first and second probes A link mechanism that is provided so as to connect both of the child retainers to each other at a position beyond the blades of the rotor wheel and that operates the first and second probe retainers in an interlocking manner on both side surfaces of the rotor wheel; , The first
Alternatively, based on a detection signal from the zero point detection sensor provided on the second probe holder and detecting a reflection plate attached to a blade to be made a zero point among the blades of the turbine wheel, and a detection signal from the zero point detection sensor. A processing device that converts a scanning distance that varies depending on the size of the rotor to be inspected into radians and performs data processing on a detection signal from the ultrasonic probe, and a display device that displays a result processed by the processing device. Ultrasonic flaw detector equipped with. 2. The processing device, after performing data processing of displaying flaw detection data obtained from the ultrasonic probe on a B scope, and then examining in advance the number of blade groups in the paragraph, 360 ° is equally divided by the total number of blades based on the number of blades and the number of the blades to which the reflecting plate for detecting the zero point is attached, and the group boundary position of the blades and the boundary position of the blades are calculated. The ultrasonic flaw detection apparatus according to claim 1, wherein the display device displays the flaw detection data in association with the group boundary position of the blades and the boundary position of the blades. 3. The processing apparatus evaluates the size of a crack-like defect based on a peak position of a pointing echo on both B scopes of an ultrasonic probe facing each other across the rotor wheel. The ultrasonic flaw detector according to claim 1. 4. The processing apparatus performs data processing for displaying flaw detection data obtained from each of the ultrasonic probes on a B scope, sets an effective flaw detection range, and calculates a maximum value at each scanning position. The ultrasonic flaw detector according to claim 1, wherein a circular graph having a radius is created and displayed on the display device. 5. First and second probe holders are arranged on both side surfaces of a rotor wheel of a rotor so as to face each other with the rotor wheel interposed therebetween, and the first and second probe holders are provided. Are provided with two ultrasonic probes, respectively, and the first and second probe holders are moved in the circumferential direction along the outer periphery of the rotor by rotation of the rotor. In an ultrasonic flaw detection method for detecting a defect generated in a blade implant portion of the rotor wheel by a contactor, a reflector is attached to a blade of the turbine wheel which is to be a zero point, and a zero point detection for detecting the reflector is performed. Providing a sensor on the first or second probe holder;
By rotating the rotor, 1 is detected by the zero point detection sensor.
The travel distance from the first detection of the reflector to the second detection of the reflector is obtained, the scanning distance is converted into radians, and the ultrasonic wave is placed on the radian-converted travel distance of one rotation of the rotor. An ultrasonic flaw detection method characterized by detecting flaw detection data from a probe in association with each other.