JP2007017164A - Ultrasonic flaw detection method and ultrasonic flaw detection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic flaw detection method capable of performing not only flaw detection over a wide area but also the ultrasonic flaw detection of inspection targets having various shapes, and an ultrasonic flaw detection system. <P>SOLUTION: A small-sized array type flaw detection sensor is used to perform ultrasonic flaw detection by converging a longitudinal wave when the incident angle of an ultrasonic wave is -20 to 20° and a transversal wave when the incident angle of an ultrasonic wave is -20° or below or 20° or above using the same sensor. The installation properties of the sensor to a narrow part are enhanced using the small-sized array type flaw detection sensor. Further, since the reflection efficiency of the longitudinal wave is high when the incident angle of the ultrasonic wave is -20 to 20° and the reflection efficiency of the transversal wave is high when the incident angle of the ultrasonic wave is -20° or below or 20° or above, the longitudinal wave and the transversal wave are transmitted and received by the same sensor to enable the ultrasonic flaw detection of the wide area. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultrasonic flaw detection method and an ultrasonic flaw detection system using an array type ultrasonic flaw detection sensor, and more particularly to an ultrasonic flaw detection method and an ultrasonic flaw detection suitable for inspecting a turbine rotor blade implantation portion of a power plant having various shapes. About the system.

  In general, as shown in FIG. 28, the turbine has a structure in which a disk 63 having a male implantation part is provided on the rotor shaft, and a moving blade 62 having a female implantation part is fitted into the disk 63. Since the rotor blades are regularly replaced, this structure is used to improve maintainability. The turbine having this structure is subjected to stress generated by rotation, and fatigue cracks and stress corrosion cracks occur in the implanted portion. For this reason, the implanted part is inspected by ultrasonic flaw detection.

  The ultrasonic flaw detection is a technique for detecting an abnormality by making an ultrasonic wave incident on an inspection object and receiving a reflected wave from the defect. A piezoelectric element is used for the ultrasonic flaw detection sensor, and by applying a high-frequency AC voltage, the volume of the piezoelectric element is expanded and contracted to oscillate ultrasonic waves. Also, ultrasonic waves are received by a piezoelectric element, and the pressure of the reflected wave is converted into a voltage and received. Since the ultrasonic sound velocity is constant within the error range for each material, the distance to the defect is evaluated by dividing the time required from transmission to reception by the sound velocity. The ultrasonic flaw detection sensor includes a single element type and an array type. The single element type is a sensor that transmits and receives ultrasonic waves with one ultrasonic element. The array type is a sensor that forms a sound field by arranging a plurality of ultrasonic elements in parallel and superposing ultrasonic waves oscillated from the ultrasonic elements. By providing the oscillation start time difference between the ultrasonic elements, the sound pressure at the inspection site is increased and the defect detection probability is improved.

  As an ultrasonic flaw detection method for the turbine rotor blade implantation portion, for example, there is a method described in Non-Patent Document 1. In this method, as shown in FIG. 29A, an ultrasonic flaw detection sensor 1 composed of a medium array ultrasonic flaw detection sensor having a total length of about 50 mm is directly brought into contact with a straight line portion on the implanted portion of the moving blade 62. It transmits and receives ultrasonic waves. Since there are various shapes of the moving blade implantation part and there is also a part with the shortest straight line length of 12 mm, in the medium-sized ultrasonic flaw detection sensor, the installation property of the sensor becomes a problem, and it is impossible to ultrasonic flaw detection of all shapes of moving blades There is a problem. Further, when the sensor is miniaturized to be a small ultrasonic flaw detection sensor having a length of, for example, 12 mm or less, the effective incident range of the ultrasonic wave is narrow, so that the flaw detection range is limited as shown in FIG. There is a problem.

"Development of multi-functional phased array flaw detection technology", Inspection Technology August 2002 (Vol. 7, No. 7), pages 37-44

  An object of the present invention is to provide an ultrasonic flaw detection method and an ultrasonic flaw detection system suitable for ultrasonic flaw detection of an inspection object having various shapes.

  The present invention uses the same array-type ultrasonic flaw detection sensor to converge a longitudinal wave within a range of −20 ° to 20 ° between the incident direction of the ultrasonic wave and the normal line of the incident surface, and to −20 °. The ultrasonic flaw detection method is characterized in that the transverse wave is converged below or at 20 ° or more.

  The present invention also includes a detection gain analyzer, an electronic scanning ultrasonic flaw detector, an array type ultrasonic flaw sensor having a length of 12 mm or less, and a sensor position moving mechanism. It is characterized by having a mechanism for converging longitudinal waves in the range of −20 to 20 ° between the incident direction and the normal of the incident surface and converging transverse waves at −20 ° or less or 20 ° or more. In the ultrasonic flaw detection system.

  According to the present invention, it is possible to perform wide-area flaw detection, and an inspection object having various shapes can be subjected to ultrasonic flaw detection.

  As already described, when ultrasonic flaw detection is performed on the turbine blade implantation part, the shortest length of the blade may be as short as 12 mm, so that the installation of the sensor becomes a problem. Further, when the sensor is downsized, there is a problem that the range in which ultrasonic flaw detection is possible becomes narrow. In order to solve these problems, the present invention uses a small array type ultrasonic flaw detection sensor, and uses the same sensor to generate a longitudinal wave at an ultrasonic incident angle of -20 to 20 °, and a transverse wave at −20 ° or less or 20 ° or more. Ultrasonic flaw detection is performed by converging. By using a small array type ultrasonic flaw detection sensor, the installation property of the sensor in a narrow portion is improved. Moreover, since the reflection efficiency of the longitudinal wave is high at an ultrasonic incident angle of -20 to 20 °, and the reflection efficiency of the transverse wave is high at −20 ° or less or 20 ° or more, the longitudinal and transverse waves are transmitted and received by the same sensor. Wide-area ultrasonic flaw detection is possible.

  In the present invention, as the ultrasonic flaw detection sensor, at least one of a small array type ultrasonic flaw detection sensor, a bending array type ultrasonic flaw detection sensor, and a flexible array type ultrasonic flaw detection sensor having a length of 12 mm or less is used. Is preferred. As a result, it is possible to perform a wide-area flaw detection by installing an ultrasonic flaw detection sensor on a moving blade having an arbitrary shape.

  A first embodiment of the present invention will be described with reference to FIGS. 1 to 11, FIGS. 24 to 27 and equations (1) to (3).

  FIG. 1 is a block diagram of an ultrasonic flaw detector in the first embodiment. An electronic scanning ultrasonic flaw detector 2, a sensor holding jig 3, an actuator driver 4, a rotating mechanism 5, an arm 6, a personal computer 7, a personal computer and ultrasonic flaw detection. Signal line 101 between the devices, signal line 102 between the personal computer and the actuator driver, signal line 103 between the ultrasonic flaw detector and the ultrasonic sensor provided on the sensor holding jig, and between the actuator driver and the actuator provided in the sensor holding jig Signal line 105, and a signal line 104 between the actuator driver and the rotating mechanism.

  FIG. 2 is a configuration diagram of the rotating mechanism in the first embodiment, in which the sensor pressing jig 3, the arm 6, the actuator 8, the motor 71, the driving wheel 70, the rotating mechanism driving unit 9 including the container 72 for fixing the motor and the driving wheel, The belt 10 and the roller 11 are used. The belt 10 is wound around the rotor shaft 64 with the roller 11 and the driving wheel 70 of the rotating mechanism driving unit 9 interposed therebetween, and electric power is supplied from the actuator driver to the motor 71 via the signal line, and the driving wheel 70 is moved by moving the belt 10. By rotating, the ultrasonic flaw detection sensor is rotated on the moving blade 62.

  FIG. 3 is a block diagram of the sensor pressing jig 3 in the first embodiment, showing a bottom view and a side view. Three small ultrasonic flaw detection sensors 1 and actuators 8 having the same number of stages as the moving blades are installed on the ultrasonic holding jig body, and the actuator and the actuator driver are connected by signal lines. Electric power is supplied to the actuator via the signal line, and the ultrasonic flaw detection sensor is moved to adjust the position and angle.

  FIGS. 4A and 4B are explanatory views showing a method of pressing the ultrasonic flaw detection sensor to the moving blade in the first embodiment. A suspension mechanism 74 and a joint 73 are provided, and the end of the ultrasonic flaw detection sensor 1 is attached. By using a curved surface, it is possible to overcome the steps of the moving blades arranged in parallel.

  The ultrasonic flaw detection step in the first embodiment is shown below.

  (First step) Enter the blade shape into the personal computer.

  (Second Step) As shown in FIGS. 6A and 6B, the sensor center position and the flaw detection site are connected with a straight line, and the incident angle and propagation distance of the ultrasonic wave are calculated. The blade shape in this calculation is two-dimensionally displayed in the X and Y coordinates with the origin at (0, 0) in FIG. The coordinates of the inflection point on the outer surface of the rotor blade and the frequent occurrence of cracks are shown in the figure. After calculation at a certain sensor installation position, the incident angle and propagation distance when the sensor is moved are calculated successively. FIG. 7 is a calculation example of the ultrasonic incident angle, where curve A is the incident angle at the first-stage crack occurrence site, curve B is the incidence angle at the second-stage crack occurrence site, and curve C is the third-stage crack occurrence site. Represents the incident angle. FIG. 8 shows an example of calculating the ultrasonic propagation distance, where curve D is the propagation distance of the first crack occurrence site, curve E is the propagation distance of the second crack occurrence site, and curve F is the third crack occurrence site. Represents the propagation distance of.

  (Third Step) Calculation results of ultrasonic propagation distance and ultrasonic incident angle, incident angle dependence of longitudinal wave reflection intensity shown in FIG. 24, incident angle dependence of transverse wave reflection intensity shown in FIG. 25, FIG. Using the dependence of the longitudinal wave reflection intensity on the ultrasonic propagation distance and the dependence of the transverse wave reflection intensity on the ultrasonic propagation distance shown in FIG. 27, calculation is performed using the following equations (1) and (2).

Longitudinal wave detection gain = f (θ) + ultrasonic wave propagation distance × longitudinal wave distance attenuation factor (1)
Here, f (θ) represents the incident angle dependence of the longitudinal wave reflection intensity shown in FIG. 24, and θ represents the longitudinal wave incident angle.

Shear wave detection gain = g (θ) + ultrasonic wave propagation distance × lateral wave distance attenuation factor (2)
Here, g (θ) represents the incident angle dependence of the transverse wave reflection intensity shown in FIG. 25, and θ represents the transverse wave incident angle.

  FIG. 9 shows a calculation example of the detection gain (Gain) using the equations (1) and (2). Curve G is the detection gain of the first-stage crack frequent occurrence location, curve H is the detection gain of the second-stage crack frequent occurrence location, curve I is the detection gain of the third-stage crack frequent occurrence location, longitudinal wave detection gain and transverse wave The gains with small values were plotted.

  (Fourth Step) The sensor position and the ultrasonic mode are determined, and the ultrasonic oscillation start time difference (delay time) between the ultrasonic elements constituting the array sensor for converging the ultrasonic wave at the flaw detection point is analyzed. The sensor position is determined so that the detection gain of the crack frequent occurrence point is minimized. As the sensor position is determined, the ultrasonic incident angle is also determined, and the ultrasonic oscillation mode is determined to be longitudinal or transverse according to the incident angle. As shown in FIGS. 24 and 25, the longitudinal wave reflection efficiency is greater than 20 °, and the transverse wave reflection efficiency is greater than 20 °. Therefore, as shown in FIG. 30, flaw detection is performed with longitudinal waves when the ultrasonic incident angle is 20 ° or less, and with transverse waves when the angle of incidence is 20 ° or more.

  FIG. 10 is a diagram for explaining a delay time calculation method, in which the delay time of the ultrasonic element 40 constituting the ultrasonic flaw detection sensor is adjusted so that the ultrasonic waves are intensified by aligning the phases at the convergence point n. The delay time is calculated by equation (3).

Delay time = distance difference between ultrasonic elements ÷ ultrasonic speed of sound (3)
FIG. 11 shows a calculation example of the delay time, where the curve J represents a longitudinal wave and the curve K represents a calculation example of a convergence condition of a transverse wave. Since the longitudinal wave and the transverse wave have different sound speeds, a difference occurs in the delay time. Shoot by using the difference in delay time.

  (Fifth Step) Information on the ultrasonic flaw detection sensor installation position determined in the fourth step is instructed to the actuator driver via a signal line.

  (Sixth Step) Commands the ultrasonic mode, delay time, and detection gain from the personal computer to the ultrasonic flaw detector via the signal line.

  (Seventh step) Based on the information on the ultrasonic flaw detection sensor installation position instructed in the fifth step, the sensor position and angle are adjusted by moving the actuator.

  (Eighth step) Electric power is supplied from the actuator driver to the rotating mechanism via the signal line, the sensor is rotated on the moving blade, and ultrasonic flaw detection is performed.

  (9th step) The ultrasonic flaw detection result is displayed on the monitor of the ultrasonic flaw detector.

  FIG. 5 is a flowchart of signal transmission in the first embodiment. The blade shape data is input from the keyboard 26 of the personal computer or the recording medium 27 constituted by one or more of the magnetic optical recording medium 27 and the magnetic recording medium. To do. Input data is transmitted to the CPU 21 via the I / O port 25. The CPU calculates the ultrasonic incident angle and propagation distance based on the shape data. Further, the detection gain is calculated based on the ultrasonic attenuation data recorded in the hard disk drive (HDD) 22, random access memory (RAM) 23, and read only memory (ROM) 24. Based on the calculation, the ultrasonic flaw detection sensor installation position is determined so as to reduce the detection gain, and is transmitted to the actuator driver via the I / O port. Further, the ultrasonic sound velocity recorded in any of the HDD, ROM, and RAM is calculated in the database, the delay time pattern is calculated by the CPU, and is transmitted to the ultrasonic flaw detector together with the detection gain via the I / O port.

  The actuator driver supplies drive power to the actuator via the D / A converter 30 based on the indication value of the ultrasonic flaw detection sensor position. The voltage and current when driving power is supplied are transmitted to the CPU via the A / D converter 29 and the I / O port, and the actual driving amount is calculated to adjust the supplied power. Further, based on the rotation instruction of the rotating mechanism, the driving power is supplied to the rotating mechanism driving unit via the D / A converter. The voltage and current when driving power is supplied are transmitted to the CPU via the A / D converter and the I / O port, and the actual driving amount is evaluated to adjust the supplied power. The relationship between the driving speed and the supplied power is determined by recording on one or more recording media of HDD, RAM, and ROM to determine the supply voltage value, and the drive amount from the actually supplied current and voltage. Is calculated backward. Further, the drive amount is transmitted to the CPU of the personal computer via the actuator driver and the personal computer I / O port, and is recorded on one or more recording media of the HDD and RAM.

  In the ultrasonic flaw detector, an instruction value for detection gain and an instruction value for delay time are transmitted to the CPU via the I / O port. The CPU oscillates the ultrasonic wave by applying a voltage with a delay time difference to the ultrasonic element via the I / O port and the D / A converter based on the instruction value of the delay time. Further, the CPU instructs the gain of the A / D converter of the input voltage of the reflected wave received by the ultrasonic flaw detection sensor via the I / O port based on the detected gain instruction value. The ultrasonic flaw detection result is transmitted to the CPU via the I / O port and recorded in the RAM or HDD. This result is displayed on the monitor via the I / O port. In addition, the data is transmitted to the CPU of the personal computer via the ultrasonic flaw detector and the I / O port of the personal computer, and recorded in the RAM or HDD of the personal computer.

  Since the present embodiment is configured as described above, ultrasonic flaw detection sensors can be installed on various shapes of moving blades. Further, by using the longitudinal wave and the transverse wave properly according to the ultrasonic incident angle, it is possible to perform flaw detection about twice as wide as the conventional flaw detection using only the longitudinal wave.

  A second embodiment of the present invention will be described with reference to FIGS. 12 to 17, FIGS. 24 to 27 and equations (1) to (3).

  FIG. 12 is an apparatus configuration diagram in the second embodiment. The electronic scanning ultrasonic flaw detector 2, the sensor holding jig 3, the rotating mechanism 5, the arm 6, the rotating mechanism driver 43, and signal lines between the rotating mechanism driver and the rotating mechanism. 104, a signal line 103 between the electronic scanning ultrasonic flaw detector and the ultrasonic sensor provided on the sensor holding jig, and a signal line 106 between the ultrasonic flaw detector and the rotating mechanical driver.

  FIG. 13 is a configuration diagram of the rotating mechanism in the second embodiment. The sensor pressing jig 3, the arm 6, the motor 71 and the driving wheel 70, and the rotating mechanism driving unit 9 including the container for fixing them, the rail 44, and the manual position adjusting mechanism. 45, comprising a rotating mechanical driver and a signal line 104 of the rotating mechanical drive unit. The ultrasonic flaw detection sensor is rotated on the moving blade 62 by supplying electric power from the rotating mechanical driver 43 to the motor 71 via the signal line 104 and rotating the driving wheel 70 sandwiching the rail 44. Further, a manual position adjusting device 45 that adjusts the sensor height by meshing a male spiral and a female spiral provided on the sensor holding jig 3 and manually rotating the male spiral is used to move the spiral. The sensor holding jig 3 is moved onto the wing 62.

  FIG. 14 is a configuration diagram of the sensor pressing jig 3 in the second embodiment, which includes an ultrasonic flaw detection sensor 1, a suspension mechanism 74, a joint 72, and a signal line 103 between the ultrasonic flaw detection apparatus and the ultrasonic sensor. The ultrasonic flaw detection sensor 1 is bent by a hinge-type joint 72, and the bent portion of the moving blade and the bent portion of the ultrasonic flaw detection sensor are matched to ensure installation. Further, as in the first embodiment, the suspension mechanism presses the moving blade against the ultrasonic flaw detection sensor so that the step between the moving blades can be absorbed by the suspension mechanism and the step can be overcome.

  The ultrasonic flaw detection step in 2nd Example is shown.

  (First step) The moving blade shape is input to the ultrasonic flaw detector.

  (Second Step) As shown in FIG. 16, each ultrasonic element and the flaw detection site are connected with a straight line, and the incident angle and propagation distance of the ultrasonic wave are calculated.

  (Third Step) Similar to the first embodiment, the detection gain is calculated using the calculation result of the ultrasonic propagation distance and the ultrasonic incident angle, the ultrasonic attenuation data of FIGS. 24 to 27, and the equations (1) and (2). Calculate FIG. 17 shows an example of detection gain calculation in the second embodiment. This calculation was performed for a moving blade having the shape shown in FIG. A curve L in the figure represents a detection gain at a first-stage crack frequent occurrence location, a curve M represents a second-stage crack frequent occurrence location, and a curve N represents a third-stage crack frequent occurrence location.

  (Fourth Step) Using the expression (3) as in the first embodiment, with the ultrasonic element having the minimum detection gain shown in FIG. Calculate the delay time.

  (Fifth step) The ultrasonic position sensor 45 is moved by moving the manual position adjusting mechanism 45 so that the bent portion of the ultrasonic flaw detection sensor and the bent portion of the moving blade coincide with each other.

  (Sixth Step) Electric power is supplied from the actuator driver to the rotating mechanism via the signal line, the sensor is rotated on the moving blade, and ultrasonic flaw detection is performed.

  (Seventh step) The ultrasonic flaw detection result is displayed on the monitor of the ultrasonic flaw detector.

  FIG. 15 is a flowchart of signal transmission in the second embodiment.

  Rotor blade shape data is input from the keyboard or recording medium of the ultrasonic flaw detector, and transmitted to the CPU via the I / O port. The CPU determines the ultrasonic element to be used by calculating the ultrasonic incident angle, ultrasonic propagation distance, and detection gain based on the shape data and the ultrasonic attenuation data shown in FIGS. The delay time is calculated using sound speed data recorded in the RAM or HDD. After the delay time is calculated, ultrasonic flaw detection is started. After starting the ultrasonic flaw detection, an instruction to start rotation is given to the CPU of the rotating mechanical driver via the ultrasonic flaw detector and the I / O port of the rotating mechanical driver.

  The CPU of the rotating mechanism driver supplies power to the rotating mechanism via the I / O port and the D / A converter in accordance with the rotation start instruction. The supply voltage and current are transmitted to the CPU via the A / D converter and the I / O port. The CPU calculates the drive amount from the relationship between the drive amount recorded in the HDD, RAM, and ROM and the supplied power, and transmits the calculated drive amount to the CPU of the ultrasonic flaw detector via the rotary mechanical driver and the I / O port of the ultrasonic flaw detector. The CPU of the ultrasonic flaw detector records the amount of rotation of the rotating mechanism and the ultrasonic flaw detection result in the HDD or RAM. In addition, the ultrasonic flaw detection result is transmitted to the monitor via the I / O port, and an image is displayed.

  Since the present invention is configured as described above, it is possible to install ultrasonic flaw detection sensors on various shapes of moving blades as in the first embodiment. Further, by using the longitudinal wave and the transverse wave properly according to the ultrasonic incident angle, it is possible to perform flaw detection over a wider area than conventional flaw detection using only the longitudinal wave. Furthermore, the sensor pressing jig can be simplified as compared with the first embodiment.

  A third embodiment of the present invention will be described with reference to FIGS. 18 to 27 and equations (1) to (3).

  FIG. 18 is an apparatus configuration diagram in the third embodiment. An electronic scanning ultrasonic flaw detector 2, a sensor holding jig 3, a rotating mechanism 5, an arm 6, a personal computer 7, a rotating mechanism driver 43, a cylinder 51, an electric pressure reducing valve 52, Gas supply pipe 53, signal line between personal computer and ultrasonic flaw detector, signal line 101 between ultrasonic flaw detector and ultrasonic sensor placed on sensor holding jig, signal line 102 between personal computer and rotary mechanical driver, rotary mechanism A signal line 104 from the driver to the rotating mechanical drive unit and a signal line 107 from the personal computer to the electric pressure reducing valve are configured. The rotating mechanism has the same structure as that of either the first embodiment or the second embodiment.

  FIG. 19 is a configuration diagram of the sensor holding jig 3 in the third embodiment. The flexible array type ultrasonic flaw detection sensor 1 having flexibility and elasticity, a balloon 54 made of rubber and having elasticity, and a gas supply pipe from the gas cylinder to the balloon. 53.

  FIG. 20 is a diagram showing a method of pressing the ultrasonic flaw detection sensor 1 against the moving blade 62 in the third embodiment. Gas is supplied to increase the internal pressure of the balloon 54, and the flexible ultrasonic flaw detection sensor having bending and stretching is moved. Press against the wings. Since the flexible ultrasonic flaw detection sensor and the balloon have flexibility, the ultrasonic flaw detection sensor can be installed on the moving blade following the step between the moving blades.

  The ultrasonic flaw detection step in 3rd Example is shown.

  (First step) The blade shape is input to the personal computer.

  (Second Step) As shown in FIG. 22, a line is drawn from the flaw detection point to the outer surface of the moving blade, and the incident angle dependence of the detection gain at each measurement point is calculated. The ultrasonic propagation distance is calculated for each incident angle, and the detection gain is calculated by applying the ultrasonic attenuation data of FIGS. 24 to 27 to the equations (1) and (2) as in the first embodiment. FIG. 23 shows an example of detection gain calculation in the third embodiment. This calculation was performed for a moving blade having the shape shown in FIG. The curve O in the figure represents the detection gain calculation result of the first-stage crack frequent occurrence location, the curve P represents the second-stage crack frequent occurrence location, and the curve Q represents the third-stage crack frequent occurrence location.

  (Third step) An incident angle at which the detection gains at the respective measurement points coincide is obtained. In this analysis example, since the minimum value of the detection gain at the third stage is 8 dB, which is larger than the other stages, the angles at which the detection gain is 8 dB at the first stage and the second stage are 10 ° and 17 °, respectively. Ultrasonic flaw detection is performed at the incident angle.

  (Fourth step) By determining the incident angle in the third step, the ultrasonic element that gives the incident angle is determined, and the ultrasonic mode is changed to the transverse wave or the longitudinal wave according to the incident angle as in the first embodiment. decide.

  (Fifth Step) The delay time is calculated using the equation (3) shown in the first embodiment.

  (Sixth Step) The ultrasonic mode, delay time, detection gain, and ultrasonic element to be used are instructed from the personal computer to the ultrasonic flaw detector.

  (Seventh step) The ultrasonic flaw detection sensor is moved onto the moving blade, the balloon is pressurized and expanded, and the ultrasonic sensor is pressed against the moving blade.

  (Eighth Step) Electric power is supplied from the actuator driver to the rotating mechanism via the signal line, the sensor is rotated on the moving blade, and ultrasonic flaw detection is performed.

  (9th step) The ultrasonic flaw detection result is displayed on the monitor of the ultrasonic flaw detector.

  FIG. 21 is a flowchart of signal transmission in the third embodiment.

  Shape data is input from a personal computer keyboard or recording media and transmitted to the CPU via the I / O port. The CPU calculates the ultrasonic incident angle dependence of the detection gain based on the shape data and the ultrasonic attenuation data shown in FIGS. 24 to 27 recorded in the RAM or HDD, so that the detection gain at each flaw detection point becomes the same. Determine the angle of incidence. The ultrasonic element to be used and the ultrasonic mode are determined according to the incident angle, and the delay time is calculated using the sound velocity data recorded in the RAM or HDD. The ultrasonic element used, the detection gain, the ultrasonic mode, and the delay time obtained by these calculations are transmitted to the CPU of the ultrasonic flaw detector via the personal computer and the I / O port of the ultrasonic flaw detector.

  The CPU of the ultrasonic flaw detection apparatus applies a voltage to the ultrasonic flaw detection sensor via the I / O port and the DA converter based on the instructed flaw detection conditions. In addition, the voltage of the ultrasonic flaw detection sensor when the reflected wave is received is transmitted to the CPU via the AD converter and I / O port, and the personal computer is transmitted via the I / O port of the ultrasonic flaw detection device and the I / O port of the personal computer. To the CPU. Further, the CPU instructs the gain of the A / D converter of the input voltage of the reflected wave received by the ultrasonic flaw detection sensor through the I / O port based on the detected gain instruction value. The ultrasonic flaw detection result is transmitted to the CPU via the I / O port and displayed on the monitor via the I / O port. The ultrasonic flaw detection result is transmitted to the CPU of the personal computer via the ultrasonic flaw detector and the I / O port of the personal computer, and recorded in the HDD or RAM.

  Rotation mechanism drive command from PC CPU is transmitted to DA converter via PC I / O port and rotation mechanism driver I / O port, power is supplied to rotation mechanism, ultrasonic flaw detection sensor is installed on moving blade Perform ultrasonic testing while rotating. The voltage and current when driving the rotating mechanism are transmitted to the CPU of the personal computer via the AD converter, the rotating mechanical driver and the I / O port of the personal computer, and the driving amount is obtained from the driving voltage and current. The relationship between the drive voltage / current and the drive amount is recorded in the HDD, ROM or RAM, and the drive current and voltage values are converted into the drive amount and recorded in the RAM or HDD.

  Since the present embodiment is configured as described above, an ultrasonic flaw detection sensor can be installed on various types of moving blades as in the above-described two embodiments, and longitudinal waves and transverse waves are converted into ultrasonic incident angles. By using properly according to this, flaw detection over a wider area is possible than conventional flaw detection using only longitudinal waves. Compared with the two embodiments described above, the ultrasonic flaw detection sensor can be easily installed on the moving blade, and the ultrasonic flaw detection conditions can be set in a wide range.

The block diagram of the ultrasonic flaw detector in 1st Example. The block diagram of the rotation mechanism in 1st Example. The block diagram of the sensor pressing jig in 1st Example. Explanatory drawing which showed the pressing method of the ultrasonic sensor in 1st Example. The flowchart of the signal transmission in 1st Example. Explanatory drawing for demonstrating the calculation method of the ultrasonic incident angle and propagation distance in 1st Example. The figure which showed the example of calculation of the ultrasonic incident angle in 1st Example. The figure which showed the example of calculation of the ultrasonic propagation distance in 1st Example. The figure which showed the example of calculation of the detection gain in 1st Example. The figure for demonstrating the delay time calculation method. The figure which showed the example of delay time calculation. The block diagram of the ultrasonic flaw detector in 2nd Example. The block diagram of the rotation mechanism in 2nd Example. The block diagram of the sensor pressing jig in 2nd Example. The flowchart of the signal transmission in 2nd Example. The figure for demonstrating the calculation method of the detection gain in 2nd Example. The figure which showed the example of calculation of the detection gain in 2nd Example. The block diagram of the ultrasonic flaw detector in 3rd Example. The block diagram of the sensor pressing jig in 3rd Example. Explanatory drawing which showed the pressing method of the ultrasonic sensor in 3rd Example. The signal transmission flowchart in 3rd Example. The figure for demonstrating the calculation method of the detection gain in 3rd Example. The figure which showed the example of calculation of the detection gain in 3rd Example. The figure showing the incident angle dependence of longitudinal wave detection intensity. The figure showing the incident angle dependence of a shear wave detection intensity | strength. The figure showing the ultrasonic wave propagation distance dependence of longitudinal wave detection intensity. The figure showing the ultrasonic wave propagation distance dependence of a shear wave detection intensity | strength. The block diagram of a turbine. Explanatory drawing which showed the inspection method of the conventional turbine rotor blade implantation part. The figure which showed the use ultrasonic mode according to an ultrasonic incident angle.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Ultrasonic flaw detection sensor, 2 ... Electronic scanning ultrasonic flaw detector, 3 ... Sensor holding jig, 4 ... Actuator driver, 5 ... Rotation mechanism, 6 ... Arm, 7 ... Personal computer, 8 ... Actuator, 9 ... Rotation mechanism drive , 10 ... belt, 11 ... roller, 21 ... CPU, 22 ... hard disk drive (HDD), 23 ... random access memory (RAW), 24 ... read only memory (ROM), 25 ... I / O port, 26 ... keyboard 27 ... Recording medium, 28 ... Monitor, 29 ... A / D converter, 30 ... D / A converter, 40 ... Ultrasonic element, 43 ... Rotating mechanical driver, 44 ... Rail, 45 ... Manual position adjusting mechanism, 51 ... Cylinder 52 ... Electric pressure reducing valve, 53 ... Gas supply pipe, 54 ... Balloon, 62 ... Rotor blade, 63 ... Disc, 64 ... Rotor shaft, 70 ... A driving wheel, 71 ... motor, a container for fixing a 72 ... motor and drive wheels, 73 ... joint, 74 ... suspension mechanism.

Claims (11)

  Using the same array-type ultrasonic flaw detection sensor, longitudinal waves are converged in the range where the angle between the incident direction of ultrasonic waves and the normal line of the incident surface is -20 to 20 °, and is -20 ° or less or 20 °. An ultrasonic flaw detection method characterized by converging a transverse wave as described above.   The ultrasonic flaw detection method according to claim 1, wherein the ultrasonic flaw detection method is used for inspection of a turbine rotor blade implantation portion of a power plant.   A plurality of array-type ultrasonic flaw detection sensors are brought into contact with the inspection target portion of the inspection object, and the angle between the incident direction of the ultrasonic waves and the normal line of the incident surface is within a range of −20 to 20 ° with each sensor. An ultrasonic flaw detection method characterized by sometimes converging longitudinal waves and converging transverse waves at other angles.   4. The ultrasonic flaw detection method according to claim 1, wherein the array type ultrasonic flaw detection sensor comprises an array type ultrasonic flaw detection sensor that is bent by a hinge.   4. The ultrasonic flaw detection method according to claim 1, wherein the array type ultrasonic flaw detection sensor comprises a flexible array type flaw detection sensor.   A detection gain analyzing device, an electronic scanning ultrasonic flaw detector, an array type ultrasonic flaw detection sensor having a length of 12 mm or less, and a sensor position moving mechanism are provided, and the ultrasonic incident direction and the incident surface of the array type ultrasonic flaw detection sensor are provided. An ultrasonic flaw detection system comprising a mechanism for converging longitudinal waves in the range of −20 to 20 ° with respect to the normal line and converging transverse waves at −20 ° or less or 20 ° or more.   The ultrasonic flaw detection system according to claim 6, comprising a plurality of the array type ultrasonic flaw detection sensors, each of which includes a mechanism for converging longitudinal waves and a mechanism for converging transverse waves.   8. The ultrasonic flaw detection system according to claim 6, wherein the array type ultrasonic flaw detection sensor comprises an array type ultrasonic flaw detection sensor that is bent by a hinge.   8. The ultrasonic flaw detection system according to claim 6, wherein the array type ultrasonic flaw detection sensor comprises a flexible array type flaw detection sensor.   An ultrasonic flaw detection system comprising a detection gain analysis device, an electronic scanning ultrasonic flaw detection device, a bending array type ultrasonic flaw detection sensor, and a sensor position moving mechanism.   An ultrasonic flaw detection system comprising a detection gain analysis device, an electronic scanning ultrasonic flaw detection device, a flexible array type ultrasonic flaw detection sensor, and a sensor position moving mechanism.

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