EP3732477A1

EP3732477A1 - Method and device for testing a component non-destructively

Info

Publication number: EP3732477A1
Application number: EP19702020.9A
Authority: EP
Inventors: Philipp Kahlert; Michael Opheys; Andreas SPERLING
Original assignee: Siemens AG
Current assignee: Siemens Energy Global GmbH and Co KG
Priority date: 2018-02-23
Filing date: 2019-01-17
Publication date: 2020-11-04
Also published as: US11733211B2; US20210041401A1; DE102018202757A1; CA3092172A1; WO2019162003A1

Abstract

The invention relates to a method for testing a component (1) non-destructively, particularly for internal defects (6, 7), comprising the following steps: a) a rotationally symmetrical component (1) having a plurality of preferably cylindrical recesses, which are arranged at one or more hole circles (3, 5) is provided, b) a transmitter probe (12) serving as an ultrasound transmitter and a receiver probe (13) serving as an ultrasound receiver are arranged spaced apart from each other outside the component (1) such that ultrasound waves can be irradiated into a shaded area (11) located behind one of the recesses (2) in the component (1) by means of the transmitter probe (12) and ultrasound waves which are diffracted at least at one defect (7) present in the shaded area (11) can be received by the receiver probe (13), and c) time of flight diffraction is used to determine whether one or more faults (7) are present in the shaded area (7). The invention also relates to an apparatus for carrying out such a method.

Description

Method and device for non-destructive testing of a

component

The invention relates to a method for non-destructive testing of a component. Moreover, the invention relates to a device for carrying out such a method.

To non-destructive components on the presence of

Errors such as cracks to investigate, various methods are known from the prior art. In addition to magnetic powder and eddy current testing, a component can also be tested non-destructively using ultrasonic waves.

For the non-destructive testing of welds, the Time of Flight Diffraction Technique (TOFD) is used, which is standardized in the standards DIN EN 583-6, DIN EN 15617 and DIN EN ISO 10863.

It is also known to use so-called phased array probes for nondestructive testing, which may include both a linear array and a matrix array. Test heads of this type have a plurality of ultrasonic sensors, which are also referred to as individual elements. By means of this, an ultrasonic wave is coupled into a component to be tested or sounded and a reflected ultrasonic signal is received again. In this case, a group of the individual elements as a transmitter and a further group as receiver elements is usually switched using an associated control unit. By way of example, reference is made to DE 10 2011 108 730 A1 in connection with phase-array ultrasonic probes.

The applicant has found that the phased array technology is particularly suitable for non-destructive testing of rotationally symmetric components comprising a plurality of recesses arranged on one or more pitch circles, for example cylindrical bores or the like. not provide reliable data for all component areas. It has been found that, in particular, errors which, viewed from the outside, lie radially under or behind recesses in such a component can not be reliably detected via the phased array technique.

However, in order to be able to make reliable statements, for example about a residual life of components, it is neces sary to be able to carry out a holistic examination of all component sections.

It is therefore an object of the present invention to provide a method for non-destructive testing of components, wel ches the error detection of those areas of components mentioned type allows that are not accessible to the prior art.

This object is achieved by a method for non-destructive testing of a component, in particular internal defects, comprising the following steps:

a) a rotationally symmetrical component which has a plurality of preferably cylindrical recess, in particular bores, which are arranged on one or more hole circles and are preferably at least substantially equidistant from one another, is provided, b) outside the component, an ultrasonic Transmitter serving Sendeprüfköpf and serving as an ultrasonic receiver Empfangsprüfköpf spaced from each other arranged such that with the Sendeprüfköpf in a shadow, which is behind one of the recesses in the component, ultrasonic waves can be irradiated, and ultrasonic waves, at least one in the Schat be bent range available error can be received by the Empfangsprüfköpf, and

c) it is determined, using the diffraction time technique, whether one or more errors exist in the shadow area. The basic idea of the present invention, in other words, is to use the ultrasound test method of the so-called diffraction time-of-flight technique (TOFD), which is already used for the destructive testing of welds, in order to obtain in rotationally symmetrical components with a plurality of recesses also those of the recesses. shaded "areas scan. For ultrasonic diffraction time technology not only a probe is used as transmitter and receiver, but transmitter and receiver are se ready and are arranged at a distance from each other.

This makes it possible, as the Applicant has found, behind recesses, which may be, for example, a plurality of holes on one or more hole circles for a flange-type fitting

A non-destructive check for errors is therefore possible by the procedure according to the invention also in areas which according to the prior art are considered non-testable. As a result, a holistic image can be obtained even if several recesses are present.

The fact that the diffraction time-of-flight technique (TOFD) does not depend on the beam angle or the reflection strength helps to detect errors that are similar to those of the

Phased array technique can not be found.

As a particularly suitable method according to the invention has been found for finding cracks, the detector of the on in the field of screwing (hollow) waves in particular of S-part turbines in nuclear power plants with a so-called "Stub shaft" or cones observed For the screw connection, there are a plurality of axial threaded bores in the hollow shaft which are arranged equidistant from each other on a circle of holes coaxial with the axis of rotation of the hollow shaft. As a result of the loading, cracks are formed in the area of the threaded bores extend both radially outward and radially inward from the respective bore, while the radially outwardly extending cracks or tear This does not apply to the radially inward cracks or sections of cracks due to the phased array technique. These are in the present as "shad tenbereiche" designated areas that are radially behind or below the holes, ie radially further inward than the prepared holes, and in particular connect to the respective hole, and which in the phased array technique be "shadowed" by the holes.

It should be noted that about the diffraction transit time technique

(TOFD) not exclusively behind recesses lying shadow areas tested, but in the context of fiction, contemporary proceedings, of course, in addition to other component areas Kgs be examined by means of this technique NEN.

A preferred embodiment of the procedural inventive method is characterized in that in a bereitgestell th component shadow areas behind multiple recesses are non-destructively checked for errors, what then - per recess, in particular hole - the steps b) and c) are performed. Of course, it is also possible that shadow areas are checked behind all in one component before existing recesses, in particular holes.

In order that a plurality of shadow areas can be checked in a simple manner, a relative movement of the component and the transmitting and receiving probe can be effected during a test procedure. Accordingly, it can be provided in a further development of the method according to the invention that the transmitting and receiving probe and the component are relative to one another be moved before given to the send and the Empfangsprüfköpf and / or the component perform a relative movement in the circumferential direction. Prinzipi ell, it is both possible that sending and Empfangsprüfköpf held at a fixed position in space, ie stationary who the while the component to be tested is moved, and vice versa or both probes and component in particular special in opposite directions to each other. Is it correct? the component about a shaft, such as a hollow shaft, can be used for the rotation of the already provided in the assembled state rotatable bare storage. To cover the entire circumference, a rotation of the shaft can be performed by 360 °. In that case, it is possible, in particular, for an annular region of the component located behind recesses, in particular bores, to be tested via TOFD.

If a relative movement of component and probes, the position of the transmitting and / or receiving test head is preferably detected relative to the component by means of at least one encoder in contact with the component.

A further preferred embodiment of the method according to the invention is characterized in that in step b) the transmitting and Empfangsprüfköpf be arranged such that ultrasonic waves that are radiated from the Sendeprüfköpf in the shadow area propagate to one side of the tenbereich lying in front of the shadow recess , And ultrasonic waves, which are diffracted at least one in the shadow area before existing error and reach the Empfangsprüfköpf he, propagate to the opposite side of the tenbereich lying in front of the shading recess. The transmitting and the Empfangsprüfköpf be arranged in step b), in particular in V-sound transmission.

Another preferred embodiment is characterized in that the component is destructively checked for errors in the mounted state. In particular, in step a) of the method, a cylindrical hollow shaft closed in the mounted state, preferably at both end faces, is provided.

The one or more hole circles on which recesses are arranged in the construction part is or are preferably coaxial with the axis of rotation of the component. In this case, the rotation axis to understand that axis, in relation to the Rotati onssymmetrie is present. In a further particularly advantageous embodiment, it is ensured that the transmitting and the Empfangsprüfköpf on a ge bent, in particular circular ring or circular ring segment-förmi gene rail preferably via a respective Prüfkopfhalter be fastened be provided. A rail of such a shape has proved to be particularly suitable for holding at least two test heads at a predetermined distance from one another on a rotationally symmetrical component, with which the probes are preferably to be brought into contact for a scanning operation, in particular for a V-sound transmission. The

Rail can be kept, for example, by a user by hand of the art that the probes held there are in contact with a component to be tested, even if the component moves during a measurement to cover a size ren test area, in particular rotated.

If a curved rail is used, it is particularly preferably coaxial with the axis of rotation of the component angeord net. Alternatively or additionally, it may be provided that the radius of the rail is selected depending on a radius of the construction part or is. The radius of the

Rail is then preferably selected as a function of the outer radius of the preferably cylindrical member is, for example, such that it slightly exceeds the outer radius.

The transmit and the Empfangsprüfköpf continue to vorgt kept at a predetermined distance from each other and / or with a defined Einschallwinkel on the rail, the predetermined distance and / or defined Einschallwinkel preferably in dependence of a radius of the component and / or the positions and / or Size of recesses in the component is selected. The distance and / or angle is expediently selected for the examination of the shadow areas in such a way that a sonication of ultrasonic waves in the respec conditions shadow area with the Sendeprüfköpf and a detection of diffracted in the shadow area waves with the receiving enable test head. In other words, the distance is preferably chosen such that the transmitting and the receiving test head "look" into the respective shadow area, which is located immediately behind the respective recess, in particular bore. Other distances and / or angles can easily be selected for testing other component areas.

In a further development, it is further provided that, depending on the dimensioning of the component and / or the position and / or size of recesses and / or the position of the transmitting and / or Empfangsprüfköpfes a blind distance to the respective recess is calculated, which defines a blind area, in which errors in the shadow area are not detectable, and the dummy distance is preferably included in a calculation of the magnitude of detected errors. Since the transmitting and the Empfangsprüfköpf "look" obliquely behind the respective recess in particular from both sides, there will usually always be a small area, which is still covered by the respective respective recess, so "shadowed" is. Its extension starting at the recess radially inwardly is referred to herein as blind spacing. If an error in a shadow area, ie behind a recess or radially further inward lying as this detected and it is known that in the component operationally there are cracks extending from the recesses, in particular Boh ments extending radially inward, it can assume that the crack also extends over the blind area, which can then be taken into account in the calculation or estimation of the crack length.

A further, particularly preferred embodiment of the method according to the invention is further distinguished by the fact that the component is additionally examined for errors with at least one phased array ultrasonic testing head. In this case, preferably the pulse-echo method can be used. At least one region of the component, which is located radially further in relation to the axis of rotation of the component, is preferably at least one of the components of the component. and a radially outward lying with respect to the Rotati onsachse range using phased array technique. It may, for example, be ensured that regions which are located in front of recesses in the construction, that is to say radially further outward than recesses, are examined for errors with at least one phased array ultrasonic testing head. The examination of further component areas with this technique can also be provided. Examples may be mentioned areas that lie between adjacent Ausnehmun gene. For a holistic image, at least all areas of a component are particularly preferred by means of

Phased array technology tested, which are not testable via TOFD and / or vice versa. Also, areas can be tested with both TOFD and the phased array technique. Then, a correlation of results of both measurement techniques suc conditions. For example, the results of the TOFD measurement can be used to verify gefun through the phased array method dene errors and possibly their size.

The non-destructive testing with at least one phased array ultrasonic probe can be done, for example, before or after a TOFD test.

Furthermore, it can be provided that an examination of the shading areas at a plurality of different, approximately two different NEN axial positions takes place. Similarly, alter natively or additionally a test on the phased array technique at several different axial positions suc conditions.

Another object of the present invention is a device for carrying out the procedural inventive method, comprising

a transmitter probe serving as an ultrasonic transmitter and adapted to radiate ultrasonic waves,

a receiving test head serving as an ultrasonic receiver, which is designed to detect ultrasonic waves, - A bent, in particular circular ring or circular ring segment-shaped rail on which the Sendeprüfköpf and the Empfangsprüfköpf are held.

The position of the transmitter and / or the Empfangsprüfköpfes may be freely adjustable on the rail, in particular locking means are provided, via which the transmitter and / or the Empfangsprüfköpf can be locked in each case in a selected position. Preferably, the transmitter and / or the Empfangsprüfköpf on the rail winkelverstell bar, held about a pivot axis pivotally to choose the Einschallwinkel comfortable and fast or can change.

It is also possible that the transmitting and / or the receiving test head at predetermined positions on the rail positio nier and lockable. The positions have been determined in particular beforehand for a component of given geometry or also several components of different geometries and can then be chosen comfortably and quickly during a measuring process. For example, it is conceivable that two different predetermined positions and / or Winkelausrich lines are provided on the rail and / or marked for a construction teilyp for the transmitting and / or the Empfangsprüfköpf. A position and / or angle adjustment can then, for example, the investigation of the shadow areas serve and another position and / or angle adjustment of the investigation in example of areas that are radially in front of recesses, so radially outward than this. Also, different set positions and / or angle settings may exist for different component types, so that the device can be adapted very quickly and reliably to another component geometry.

The transmitting and / or receiving test heads are furthermore preferably each held on the rail via a test head holder manufactured in particular by means of a rapid prototyping method. Through generative manufacturing processes can particularly suitable test head holder can be produced, with a maximum of flexibility in terms of shape is made.

The device according to the invention further comprises, in a further development, at least one encoder to be brought into contact in particular with a component to be tested, which is designed to detect the position of the transmitting and / or receiving test head relative to the component. With an encoder can in that case that component and probes perform a Relativbe movement to each other, for example, to scan several areas shadow for error, reliably the respective relative position are detected.

Another embodiment is characterized in that the device comprises at least one phased array ultrasonic probe, so that in addition a non-destructive testing of a component via the phased array method is possible. If such a test head is provided, the device further preferably comprises a phased array encoder which is in particular to be brought into contact with a component to be tested and which is assigned to the phased array ultrasound probe, which is designed to determine the position of the phased array -Ultra- sound-Prüfköpfes relative to the component to capture. For the phased array ultrasonic probe can also be provided a test head holder, which was preferably also manufactured by means of a rapid prototyping method. The test head holder may have a handle over which a user Be the test head brin comfortable to a desired position and can hold in this.

Furthermore, the device may comprise at least one memory and / or evaluation unit, with which measurement signals which are detected by the probes and / or one or more encoders are stored and / or evaluated. The storage and / or evaluation unit, for example, an ultrasound device - optionally in conjunction with a computer - include or be given by such. It should be noted that it is possible in principle that the device according to the invention in addition to the rail held at the transmit and the Empfangsprüfköpf and possibly before existing phased array probe still includes one or more wei tere probes, such as by simultaneous Messun to be able to test more component volumes in less time. This applies correspondingly ren for the procedural invention.

Further features and advantages of the invention will become apparent from the following description of an embodiment of he inventive method and the Vorrich device according to the invention with reference to the accompanying drawings. That's it

FIG. 1 shows a schematic partial view of a "stub shafts" or pin of a hollow shaft of an S sub-turbine of a nuclear power plant,

Figure 2 is a purely schematic partially cut Dar position of a hollow shaft of an S-part turbine of a nuclear power plant, to which the "stub shaft" or Zap fen of Figure 1 is screwed,

3 shows a purely schematic partially cut Dar position to illustrate the examination of the hollow shaft of Figure 2 with the phased array technique,

Figure 4 is an enlarged purely schematic partially ge

2 is a sectional view for illustrating the non-destructive testing of a shadow region of the hollow shaft from FIG. 2 via TOFD,

5 is a purely schematic partial view of the end face of the hollow shaft of Figure 2 with a Ausfüh tion form of a device according to the invention for non-destructive testing, Figure 6 is a perspective view of the hollow shaft and Tei len of the device of Figure 5, and

Figure 7 is a schematic perspective view of a

Phased array probe holder on the hollow shaft of Figure 2.

FIG. 1 shows, in a purely schematic representation, a frontal view of the upper half of a pin 1, also referred to as "stub shaft", which faces the hollow shaft 2, which is not shown in FIGS Kernkraftwer kes is screwed.

As can be seen in Figure 1, a plurality of extending in the axial direction through holes 3 in the pin 1 is provided on the front side, which are arranged on a in Figure 1 for illustrative purposes drawn hole circle LI is. The pin 1 has the front side nor a plurality of zylin derförmigen recesses 4, the circle on a further hole L2 with a slightly larger radius than the bolt circle LI of the through holes. 3 are arranged, and whose diameter clearly falls below those of the through holes 3. The cylindrical recesses 4 are provided for balancing weights. Both hole circles LI, L2 are coaxial with the axis of rotation R of the shaft 1, which is perpendicular to the plane of the drawing in Figures 2 to 5.

In the hollow shaft 2 shown in Figure 2 are the

Through holes 3 corresponding threaded holes 5 are provided, which are also arranged according to the bolt circle LI, and in which in the assembled state in the figures, not shown, screws are screwed, which extend through the through holes 3 and their heads rest on stop surfaces provided there, as it From a flange-like fitting is well known.

As the Applicant could determine in the context of a routine inspection, due to operational reasons in the area of the threaded holes 5 in the hollow shaft 2 for the screw connection with the "stub shaft" or pin 1, in particular in Be rich the bottom of the threaded holes 5, cracks which emanate from the threaded bores 5 and have an orientation in the radial direction both outwardly and inwardly.This is shown by way of example in Figure 2 for three of the threaded bores 5. It should be noted that in Figure 2 only some of the Specifically, only five of the threaded bores 5 are shown by way of example in the shaft 2 provided on the front side of the shaft 2. The cracks extending radially outward from the respective threaded bore 5 are denoted by 6 and extend radially from the respective threaded bore 5 inside extending with 7.

The turbine shaft 2 is a safety-relevant, highly stressed component, which is why a non-destructive examination of the areas around the threaded holes 5 to verify the freedom from cracks is required. It has been found that the radially outwardly extending cracks 6 by means of the ultrasonic phased array technique, in which the crack detection tion based on exploiting reflected Ultraschallallsig nals, are detectable.

3, which shows an enlarged partial view of the Turbi nenwelle 2 in section with only one recognizable tapped hole 5, this is illustrated purely schematically. For the non-destructive testing by means of the phased array technique, an ultrasonic phased array test head 8 is arranged on the surface of the turbine shaft 2, which is shown purely by way of example in FIG. 3 in three different test positions. The ultrasonic phased array test head 8 comprises a plurality of individual elements 9, each of which can be used as ultrasound Transmitter or receiver can serve. In the figure 3 of the majority of the individual elements 9 only three pieces are indicated purely by way of example.

For each of the three test positions, a circular sector 10 is in each case drawn, which is intended to illustrate a sector scan in the circumferential direction. The central circular sector 10 is hatched for better distinction. For a sector scan, ultrasonic signals are sent or received and recorded in a de-defined central angle range by electronic control of several individual elements 9 per probe position. FIG. 3 illustrates a passing over of the test head 8, in which a possible error, which is oriented as a crack 6 of the threaded bore 5 radially to the outer surface of the turbine shaft 1, is detected by sector scan. At the right of the three probe positions, the probe 8 can detect the diffraction signals of the tip of the crack 6 with the outer central ray. At the left test head position, the tip of the crack 6 is detected almost with the vertical right Zentralstrahlschallung. This sector insertion in combination with a movement of the test head 8 in the circumferential direction (and / or a rotation of the shaft 1) made it possible to analyze the dynamics of an error in the circumferential direction. To detect possible fault courses in the axial direction of the Rich Phaser Array 8 can be rotated by 90 ° angeord net and also rotated in the circumferential direction around the shaft (and / or vice versa). For the non-destructive testing, ultrasonic waves with fixed sound-angle ranges are coupled into the shaft 2 by a plurality of individual elements 9 and ultrasonic waves reflected at the radially outwardly extending crack 6 are detected by a plurality of individual elements 9 connected as Emp catcher, so that the latter can be found.

The situation is different for the radially inwardly extending crack 7. This is - from the perspective of the probe 8 - back ter the threaded hole 5, which is reflected with the probe 8 coupled ultrasonic signals and thus prevents that ultrasonic signals can be injected into the area behind it. For this reason, the area lying radially under or behind the threaded bore 5 is referred to as shadow area 11. Due to the shading effect of the threaded hole 5, it is not possible, please include using the phase-array technique to detect the radially inwardly extending crack 7.

This problem is addressed by the present invention so that the non-destructive inspection of the shadow areas 11 behind the threaded holes 5 in the hollow shaft 1, the Ult raschall-Laufzeitbeugungstechnik (Time of Fligth Diffraction Technique, TOFD) is used.

In this not only a test head 8 is used, which serves as a transmitter and receiver, but it is a separate transmitter and receiver are used, which can be combined with stepped Vorke wedges to achieve different ultrasonic impact angle in the shaft 1 , Specifically, as shown purely schematically in Figures 2 and 4, serving as an ultrasonic transmitter Sendeprüfköpf 12 and serving as an ultrasonic receiver Empfangsprüfköpf 13 spaced apart on the outside of the shaft 2 arranged in such a way that with the Sendeprüfköpf 12th in a shadow area 11 behind a threaded hole 5 ultrasonic waves can be irradiated and ultrasonic waves that are diffracted at least one existing in the shadow area 11 crack 7, can be received or detected by the Empfangsprüfköpf 13. In this case, an interaction of insonification angle and test head spacing must be taken into account in order to define a desired depth of focus. In FIG. 2, for purely schematic illustration purposes, an ultrasound signal radiated by the transmit probe 12 is representative of the central line 14 and the central beam of the receiver 15 as the middle line 15 representing the ultrasonic wave diffracted at a crack 7 in the shadow region 11 and propagating to the receive probe 13 , drawn. FIG. 4 shows an enlarged schematic representation for non-destructive testing of the shadow region 11 of the central threaded bore 5 according to the invention via TOFD, wherein a plurality of representative lines 14 and 15 for the transmitting and Empfangsprüfköpf 12, 13 are shown, each representing the 6dB sound pressure drop. Since the central beam 15 of the Empfangsprüfköpfes 13 and the central beam 14 of the transmission probe head 12 intersect the tip of the crack 7, a de tection of the error via TOFD is easily possible. A central threaded bore 5, whose shadow region 11 can be tested in the position of the probes 12, 13 shown in FIG. 4, is also marked in FIG. 4.

Ultrasonic waves, which are sounded by the Sendeprüfköpf 12 in the shad tenbereich 11, propagate to one side of lying in front of the shadow area 11 threaded hole 5 (see the lines 14) and ultrasonic waves, which diffracted at one or more cracks 7 in the shadow area 2 and 4 on the right side of the threaded hole 5 (see line (s) 15). The probes 12, 13 are arranged such that there is a so-called V-sound transmission.

The two probes 12, 13 are part of an embodiment of a device according to the invention for non-destructive testing, which is shown purely schematically in Figures 5 and 6. The device comprises, in addition to the probes 12, 13 a curved, in this case circular segment-shaped rail 17. As can be seen in particular in Figure 5, the belonging to the rail 17 radius is slightly larger than the outer radius r _{A of} the hollow shaft 1, which in the figure 2 and the annular segment-shaped rail 17 extends in the present case over an angle of about 100 °, that is less than one third of a full circle.

On the rail 17, the two probes 12, 13 are each connected to one another by means of a rapid prototyping method. Taken transmit and Empfangsprüfkopfhalter 18, 19 spaced from each other and held in one. Of each of the two test head holder 18, 19 while one of the probes 12, 13 is taken and that at the radially inwardly facing end of the respective probe holder 18, 19, so that the respective test head 12, 13 with the surface of the hollow shaft 1 in Contact comes when the rail 17, as shown in Figures 5 and 6 ge, is arranged. The aufgenomme of the holders 18, 19 NEN probes 12, 13 are not visible in the figure 5.

The device further comprises an encoder 20 which is held on the transmit probe holder 18. The encoder 20 serves to detect the current position of the test head holder received by the transmitting Sendeprüfköpfes 12 relative to the hollow shaft 2, when the probes 12, 13 and the hollow shaft 1 perform a relative movement to each other during a measuring operation, which will be discussed further below.

The two probes 12, 13 and the encoder 20 are connected to a central memory and evaluation unit 21 of the device via cables not shown in the figures.

For a non-destructive examination of the hollow shaft 2 to a TOFD measurement with the device of Figure 5 is carried out, for this purpose, the rail 17 with the ge held therein test head holders 18, 19 and the two probes 12, 13 by hand shell side of the hollow shaft 2 sequentially is arranged at meh er predetermined axial position, as shown for a position in Figures 5 and 6. The multiple axial positions at which the rail 17 with the probes 12, 13 are successively arranged result from fixed turbine blade positions. Generally, per blade row before (steam inlet side) and behind (steam outlet side) the blades an axial posi tion chosen to check the entire axial portion of the recesses, here threaded holes 5, to check. The exact axial positions result from the concrete turbine design. The rail 17 is, when, as shown in Figures 5 and 6 for an axial position, is arranged, coaxial with the axis of rotation R of the shaft 2. It may be provided in the figures, not shown scaffolding side of the shaft 2, which a user can commit to hold the rail 17 accordingly.

The probes 12, 13 are, when the rail 17 is positioned as shown in Figures 5 and 6, activated, so that the Sendeprüfköpf 12 emits ultrasonic waves and the Emp catch test head 13 records, and the hollow shaft 2 is about its axis of rotation R once complete, so 360 ° ro. Due to the relative movement of probes 12, 13 and

Wave 2 in the circumferential direction are successively in all shad tenbereiche 11 behind the threaded holes 5 on the hole circle LI ultrasonic waves with the Sendeprüfköpf 12 and ultrasonic waves, the existing possibly in the respec conditions shadow area 11, radially inward duri fenden cracks. 7 can be diffracted, can be detected with the Empfangsprüf- head 13, so that the shadow areas 11 behind all threaded holes 5 are tested successively nondestructive error. It should be noted that, in particular, a rear area, that is to say radially further inward than the bores 5, is checked via the scanning during a complete rotation of the shaft 2.

It should also be noted that due to the fact that the transmitting and the Empfangsprüfköpf 12, 13 "look" obliquely behind the respective bore 5 from both sides, there is always a small, radially inwardly immediately adjacent to the respective bore, 11 lying in the respective Schattenbe rich lying "blind area", which is still covered by the Ge threaded hole 5, so "shadowed" is. Its extent starting at the respective bore 5 ra dial inward is referred to herein as blind spacing, which in particular depends on the dimensioning of the shaft 2 and / or the position and / or size of the threaded bore. ments 5 and / or the position of the transmitting and / or receiving test head 12, 13 calculated and, if necessary, in a calculation of the size of detected cracks 7 is included.

Following the TOFD measurement of the shadows 11 Kings nen - also via TOFD - other areas are non-destructively checked for errors, such as areas that lie radially in front of the threaded holes 5, so radially outward than this lie. For this purpose, the distance between the two Probes 12, 13 and the two these supporting probe holder 18, 19 at the

Rail 17 changed, about reduced, and / or the insonction angle of both probes 12, 13 is increased by Vorlaufkeile about, whereby the probes 12, 13 "look" on a radially further outward location (the focal depth of the central beam is reduced) and the shaft 2 is again rotated 360 °, while ultrasonic waves are emitted with the transmitting probe 12 and recorded with the receiving probe 13. As a result, an annular portion of the shaft 2 ge checks that surrounds the holes 5. Positions for the transmit and receive probe holder 18, 19 can be defined on the rail 17, which correspond to different test areas, for instance different radial positions.

Following the TOFD measurement of the shadow regions 11 and, if appropriate, further component regions, the shaft 2 can additionally be tested by means of an ultrasonic phased array test head 8, as shown schematically in FIG. In the exemplary embodiment described here, an ultrasonic phased array test head 8 is used which, in analogy to the test heads 12, 13, is produced by a further test head holder 22 produced by a rapid prototyping method, which is located in a schematic perspective view in Figure 7 ge shows is added. The probe holder 22 has a handle 23, over which a user can comfortably and safely position it on the outside of the shaft 2. Via a cable 25, the ultrasound phased array test head 8 received by the test head holder 22 is provided in a well-known manner with a phased array detector not visible in the figures. Storage and evaluation unit connected. Also for the phased array measurement, the shaft 2, in order to cover the entire circumference, rotates. With a phased array probe 8 associated, held on the phased array probe holder 22 phased array encoder 24 while the way is taken. The phase array probe 8 is, so that the measuring points of the phased array measurement can be merged with those of the TOFD measurement, at a predetermined start Posi tion and arranged at the same axial positions as the TOFD test. The results of the TOFD and the phased array measurements can then be correlated.

As a result, the shaft 2 can be reliably checked for errors, especially in the particularly safety-relevant area of the threaded holes 5, and it can be a reliable and safe operation of the turbine and thus of this comprehensive send nuclear power plant can be ensured.

It should be noted that it is of course also possible that the "Stub shaft" or pin 1 is tested non-destructively for errors in the above-described manner, in which case via TOFD are checked in particular radially behind the areas lying through holes 3.

Although the invention has been further illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Claims

claims

1. A method for non-destructive testing of a component (2), in particular internal defects (6, 7), comprising the following steps:

a) a rotationally symmetrical component (2) which has a plurality of preferably cylindrical recesses, in particular holes (5), which are arranged on one or more pits (LI) and are preferably equidistant from each other, at least in essence.

b) outside of the component (2) serving as an ultrasonic transmitter Sendeprüfköpf (12) and serving as an ultrasonic receiver Reception Probe (13) beab beabet each other arranged such that with the Sen deprüfkopf (12) in a shadow area (11 ), which is behind one of the recesses (5) in the component (2), Ult raschallwellen can be irradiated, and ultrasonic waves, which are at least one in the Schattenbe rich (11) existing error (7) diffracted by the Empfangsprüfköpf (13) can be received, and c) it is determined using the diffraction time technique whether one or more errors (7) are present in the shadow area (11).

2. The method according to claim 1,

characterized in that

the shadow areas (11) behind several recesses (5) in the component (2) in each case by performing steps b) and c) non-destructively checked for errors (7).

3. The method according to claim 1 or 2,

characterized in that

in particular for the non-destructive testing of a plurality of shadow areas (11) of the transmitting and receiving inspection heads (12, 13) and the component (2) are moved relative to each other, preferably the transmitting and the Empfangsprüfköpf (12, 13) and / or the component ( 2) perform a relative movement in the circumferential direction,

wherein the position of the transmitting and / or Empfangsprüfköpfes (12, 13) relative to the component (2) is detected in particular by means of at least one with the component (2) in contact encoder (20).

4. The method according to any one of the preceding claims, characterized in that

in step b), the transmitting and Empfangsprüfköpf (12, 13) are arranged such that ultrasonic waves from the probe head (12) in the shadow area (11) are emitted to one side of the front of the shadow area (11) lying recess ( 5) propagate, and ultrasound waves, which are at least one in the shadow area (11) existing error ler (7) are bent and the Empfangsprüfköpf (13) errei surfaces, to the opposite side of the rich before the Schattenbe (11) recess (5 ) propagate.

5. The method according to any one of the preceding claims, characterized in that

the component (2) is checked non-destructively for failure in the mounted state, in particular in step a) in the assembled state, preferably on both end faces verschlos sene cylindrical hollow shaft (2) is provided as a component.

6. The method according to claim 5,

characterized in that

the hole circle or circles (LI) on which the recesses (5) in the provided component (2) are preferably arranged, is or are coaxial with the axis of rotation (R) of the component (2).

7. The method according to any one of the preceding claims, characterized in that

the transmitting and the Empfangsprüfköpf (12, 13) on a geboge nen, in particular circular ring or circular segment-shaped rail (17) preferably via a respective Prüfkopfhalter (18, 19) are provided fixed, and in particular the rail (17) coaxial the rotation axis (R) of the component (2) is arranged, and / or radius of the rail (17) in dependence on a radius (r _A ) of the component (2) is selected.

8. The method according to claim 7,

characterized in that

the transmitting and the Empfangsprüfköpf (12, 13) in a pre-given distance from each other and / or with defined A sound angles to the rail (17) are held,

wherein the predetermined distance and / or defined insonification angle preferably the predetermined distance preferably in depen dence of a radius of the component (2) and / or the positions and / or size of recesses (5) in the component (2) GE is selected.

9. The method according to any one of the preceding claims, characterized in that

depending on the dimensioning of the component (2) and / or the position and / or size of recesses (5) and / or the position of the transmitting and / or Empfangsprüfköpfes (12, 13) calculated a blind distance to the respective recess (5) which defines a blind area in which error (7) is not detectable in the shadow area (11), and the blind pitch is preferably included in a calculation of the magnitude of detected errors (7).

10. The method according to any one of the preceding claims, characterized in that

the component is additionally examined non-destructively for defects (6, 7) by means of at least one phased-array ultrasonic testing head (8).

11. Apparatus for carrying out the method according to one of the preceding claims, comprising

- Serving as an ultrasonic transmitter Sendeprüfköpf

(12), which is designed to emit ultrasonic waves,

a receiving test head (13) serving as an ultrasonic receiver, which is designed to detect ultrasonic waves,

- A curved, in particular circular ring or circular segment-shaped rail (17) on which the (12) and the Empfangsprüfköpf (13) are held.

12. Device according to claim 11,

characterized in that

the position of the transmitting and / or the receiving test head (12, 13) on the rail (17) is freely adjustable,

wherein preferably locking means are provided, via which the transmitter and / or the Empfangsprüfköpf (12, 13) can be locked in each case in a selected position, or that the transmitting and / or the Empfangsprüfköpf (12, 13) to Festge set positions the rail (17) can be positioned and locked.

13. Device according to one of claims 11 or 12,

characterized in that

the transmitting and / or receiving test heads (12, 13) are each held on the rail (17) via a test head holder (18, 19), preferably manufactured by means of a rapid prototyping method.

14. Device according to one of claims 11 to 13,

characterized in that

at least one in particular to be tested with a component to be tested (2) to be brought into contact encoder (20) is provided which is adapted to the position of the transmitting and / or Emp fangsprüfkopfes (12, 13) relative to the component (2) to capture .

15. Device according to one of claims 11 to 14,

characterized in that

the apparatus comprises at least one phased array ultrasound probe (8) and preferably at least one phased array associated with the phased array ultrasound probe (8), in particular to be brought into contact with a component (2) to be tested. Encoder (24) adapted to detect the posi tion of the phased array ultrasonic probe (8) relative to the component (2).