Method and assembly for ultrasonic pipe inspection
The ultrasonic inspection method using multiple probes with specific angles and polarization techniques effectively addresses the challenge of irregular surfaces in pipes, enabling reliable crack detection and sizing within pipes.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- INTERCONTROLE SA
- Filing Date
- 2024-06-24
- Publication Date
- 2026-05-22
AI Technical Summary
Ultrasonic inspection of pipes is complicated by irregularities on both external and internal surfaces, particularly at welds, which disrupt signal emission and interpretation, making it difficult to detect and size cracks reliably.
An ultrasonic inspection method using at least two probes, one for establishing an internal profile and another for detecting indications, with specific angles and polarization methods to form coherent ultrasonic images, accounting for surface irregularities, and optionally a third probe for confirmation and sizing.
Enables reliable detection and sizing of cracks on the internal surface of pipes with irregularities, providing precise positioning and measurement of indications, even when external and internal surfaces are not smooth.
Smart Images
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Abstract
Description
Title of the invention: Method and assembly for ultrasonic inspection of a pipe
[0001] The present invention relates generally to the ultrasonic inspection of a pipe.
[0002] Ultrasonic inspection can be used to detect and size indications within the volume of a pipe and, in particular, cracks on the internal surface of a pipe, including near a weld.
[0003] Ultrasonic probes are typically placed on the external surface of the piping, which is more easily accessible than the internal surface.
[0004] However, at the weld, the external surface has significant irregularities, which can interfere with the acoustic coupling of the ultrasonic probe to the external surface, which disrupts the emission of signals and complicates the interpretation of the signals collected.
[0005] The internal surface of the piping also has irregularities which complicate the interpretation of the signals collected.
[0006] In this context, the invention aims to provide an ultrasonic inspection method which makes it possible to detect indications in the volume and on the internal surface of the piping and in particular to reliably size cracks, even when the piping has irregularities in shape at the external and internal surfaces.
[0007] To this end, the invention relates to an ultrasonic inspection method for piping, based on the use of at least two ultrasonic probes, comprising the following steps:
[0008] - establishment of an internal profile of an internal surface of a section to be inspected The piping, a first ultrasonic probe being moved over an external surface of said section to be inspected at a plurality of regularly spaced, predetermined positions, the step of establishing said internal profile of the internal surface comprising, at each predetermined position, a first operation of determining a first external profile of the external surface of the section to be inspected and a second operation of determining said internal profile of the internal surface, during the first operation a first ultrasonic image consisting of longitudinally polarized waves being formed by the first ultrasonic probe positioned at an angle of incidence between -15° and +15° with respect to a normal to said external surface, the first external profile being determined by analyzing the first ultrasonic image, during the second operation a second ultrasonic image consisting of longitudinally polarized waves being formed by the first probe ultrasonic positioned with an angle of incidence between -15° and +15° relative to a normal to said external surface, the second ultrasonic image (65) being formed taking into account the first external profile, the internal profile being determined by analyzing the second ultrasonic image;
[0009] - detection of possible indications in the volume and on the internal surface of the section to inspect piping, a second ultrasonic probe being moved over an external surface of an adjacent section of said section to be inspected at a plurality of regularly spaced determined positions, the step of detecting possible indications comprising, at each determined position, a third operation of determining a second external profile of the external surface of the adjacent section and a fourth operation of detecting possible indications, during the third operation a third ultrasonic image consisting of longitudinally polarized waves being formed by the second ultrasonic probe positioned with an angle of incidence between 0° and 28° with respect to a normal to said external surface, the second external profile being determined by analyzing the third ultrasonic image,During the fourth operation, a fourth ultrasonic image of the internal surface of the section to be inspected, consisting of transversely polarized waves, is formed by the second ultrasonic probe. This fourth ultrasonic image is formed taking into account the second external profile. Any indications are detected, and their positions on the internal profile of the internal surface of the section to be inspected are determined using the fourth ultrasonic image and the internal profile previously established during the second operation.
[0010] The first ultrasonic probe makes it possible to establish the profile of the internal surface of the inspected section of pipe.
[0011] The second ultrasonic probe makes it possible to detect any indications located within the volume and on the internal surface. In the latter case, knowledge of the internal surface profile allows for reliable detection of indications that would be open, and also allows them to be positioned on the internal surface.
[0012] Indications located within the volume are those located within the metal constituting the thickness of the pipe, without opening onto the internal surface. In other words, they are the indications located within the pipe wall. Indications located on the internal surface are those that open onto the internal surface. The method is particularly well-suited for detecting this latter type of indication, which opens onto the internal surface.
[0013] A third probe may optionally be used to confirm and size any indications of cracking.
[0014] The process may also have one or more of the following characteristics, considered individually or in all technically possible combinations:
[0015] - the first ultrasonic probe is a multi-element probe comprising a plurality of transmitter / receiver elements functioning both as transmitters and receivers;
[0016] - the second ultrasonic image is formed taking into account the first profile external by applying to the emitting elements a set of phase delays corresponding to the first external profile;
[0017] - the first ultrasonic probe is driven to form the first image ultrasonic according to the FMC method, the first external profile being determined by analyzing the first ultrasonic image by the TFM method;
[0018] - the first ultrasonic probe is driven to form the second image ultrasonic according to the FMC method, the internal profile being determined by analyzing the second ultrasonic image by the TFM method;
[0019] - the second ultrasonic probe is a multi-element probe comprising a plurality of transmitting / receiving elements functioning both as transmitters and receivers, or comprising a plurality of transmitting elements and a plurality of receiver elements distinct from the transmitting elements;
[0020] - the fourth ultrasonic image is formed taking into account the second external profile by applying to the receiving elements a set of phase delays corresponding to the second external profile;
[0021] - the second ultrasonic probe is driven for the formation of the third image ultrasonic according to the FMC or PWI method, the second external profile being determined by analyzing the third ultrasonic image by the TFM method;
[0022] - the second ultrasonic probe is driven to form the fourth image ultrasonic according to the PWI method, any indications being detected and their positions on the internal profile of the internal surface of the section to be inspected being determined by analyzing the fourth ultrasonic image by the TFM method;
[0023] - at the stage of detecting possible indications, the indications are detected by corner effect;
[0024] - the method includes a step of determining a height of the or each indication, a third ultrasonic probe being moved to a plurality of regularly spaced determined positions on the external surface of said adjacent section, or on an external surface of another adjacent section of said section to be inspected, the step of determining a height of the or each indication comprising, at each determined position, a fifth operation of determining a third external profile of the external surface of the adjacent section or the other adjacent section and a sixth operation of determining the presence of indication and measurement height, during the fifth operation a fifth ultrasonic image consisting of longitudinally polarized ultrasonic waves being formed by the third ultrasonic probe positioned with an angle of incidence between 0° and 28° relative to a normal to said external surface, the third external profile being determined by analyzing the fifth ultrasonic image, during the sixth operation a sixth ultrasonic image of the internal surface of the section to be inspected consisting of longitudinally polarized waves being formed by the third ultrasonic probe, the sixth ultrasonic image being formed taking into account the third external profile, any indications being detected and the height of the or each indication being determined using the sixth ultrasonic image and possibly the first internal profile previously established during the second operation;
[0025] - the third ultrasonic probe is a multi-element probe comprising a plurality of transmitting / receiving elements functioning both as transmitters and receivers, or comprising a plurality of transmitting elements and a plurality of receiver elements distinct from the transmitting elements;
[0026] - the sixth ultrasonic image is formed taking into account the third profile external by applying to the receiving elements a set of phase delays corresponding to the third external profile;
[0027] - the third ultrasonic probe is driven for the formation of the fifth image ultrasonic according to the FMC or PWI method, the third external profile being determined by analyzing the fifth ultrasonic image by the method;
[0028] - the third ultrasonic probe is driven to form the sixth image ultrasonic according to the TWI method, any indications being detected and the height of the indication or each indication being determined by analyzing the sixth ultrasonic image by the TFM method;
[0029] - a depth of an open end of the or each indication at the level the internal surface of the section to be inspected is determined at the stage of detecting possible indications, a depth of a closed end of the or each indication being determined at the stage of determining a height of the or each indication;
[0030] - during the sixth operation, the third ultrasonic probe forms the sixth ultrasonic image by emission of incident ultrasonic waves having a wavelength chosen to cause diffraction of said incident ultrasonic waves by the or each indication.
[0031] According to a second aspect, the invention relates to an ultrasonic pipe inspection system, the system comprising:
[0032] - a first ultrasonic probe intended for establishing an internal profile of an internal surface of a section of piping to be inspected;
[0033] - a first carrier, adapted to move the first ultrasonic probe to a plurality of regularly spaced determined positions on an external surface of said section to be inspected;
[0034] - a first controller configured to perform, at each determined position, a first operation of determining a first external profile of the external surface of the section to be inspected and a second operation of determining said internal profile of the internal surface, during the first operation a first ultrasonic image consisting of longitudinally polarized waves being formed by the first ultrasonic probe positioned with an angle of incidence between -15° and +15° with respect to a normal to said external surface, the first controller being configured to determine the first external profile by analyzing the first ultrasonic image, during the second operation a second ultrasonic image consisting of longitudinally polarized waves being formed by the first ultrasonic probe positioned with an angle of incidence between -15° and +15° with respect to a normal to said external surface, the second ultrasonic image being formed taking into account the first external profile,the first controller being configured to determine the internal profile by analyzing the second ultrasonic image;
[0035] - a second ultrasonic probe intended for the detection of possible indications in the volume and on the internal surface of the section of piping to be inspected;
[0036] - a second carrier, adapted to move the second ultrasonic probe to a plurality of regularly spaced determined positions on an external surface of an adjacent section of said section to be inspected;
[0037] - a second controller configured to perform, at each determined position, a third operation to determine a second external profile of the external surface of the adjacent section and a fourth operation to detect any indications in the volume and on the internal surface of the section to be inspected, during the third operation a third ultrasonic image consisting of longitudinally polarized waves being formed by the second ultrasonic probe positioned with an angle of incidence between 0° and 28° with respect to a normal to said external surface, the second controller being configured to determine the second external profile by analyzing the third ultrasonic image, during the fourth operation a fourth ultrasonic image of the internal surface of the section to be inspected consisting of transversely polarized waves being formed by the second ultrasonic probe, the fourth ultrasonic image being formed taking into account the second external profile,The second controller is configured to detect any indications and determine their positions on the internal profile of the internal surface of the section to be inspected, using the fourth ultrasonic image and the internal profile previously established during the second operation.
[0038] The assembly may further include:
[0039] - a third ultrasonic probe intended for determining a height of the or each indication;
[0040] - a third carrier, adapted to move the third ultrasonic probe to a plurality of regularly spaced, predetermined positions on the external surface of said adjacent section, or on an external surface of another adjacent section of said section to be inspected,
[0041] - a third controller configured to perform, at each determined position, a fifth operation of determining a third external profile of the external surface of the adjacent section or the other adjacent section and a sixth operation of determining the presence of an indication and height measurement, during the fifth operation a fifth ultrasonic image consisting of longitudinally polarized ultrasonic waves being formed by the third ultrasonic probe positioned with an angle of incidence between 0° and 28° with respect to a normal to said external surface, the third controller being configured to determine the third external profile by analyzing the fifth ultrasonic image, during the sixth operation a sixth ultrasonic image of the internal surface of the section to be inspected consisting of longitudinally polarized waves being formed by the third ultrasonic probe, the sixth ultrasonic image being formed taking into account the third external profile,the third controller configured to detect any indications and determine the height of the indication(s) using the sixth ultrasonic image and the internal profile previously established during the second operation..
[0042] Other features and advantages of the invention will become apparent from the detailed description given below, by way of example and not limitation, with reference to the accompanying figures, among which: - [Fig.1]: [Fig.1] is a step diagram illustrating the inspection process of the invention; - [Fig.2]: [Fig.2] is a simplified schematic representation of the ultrasonic inspection system of the invention; - [Fig. 3]: [Fig. 3] is a schematic illustration of the SU operation of the method of [Fig.1], for establishing the profiles of the external surface of the piping; - [Fig. 4]: [Fig. 4] is a schematic illustration of operation S12 of the process [Fig.1], for establishing the profile of the internal surface of the process of the [Fig.1]; - [Fig.5]: [Fig.5] is a schematic illustration of operation S21 of the process of [Fig.1], for establishing the profiles of the external surface of the piping; - [Fig.6]: The [Fig.6] is a schematic illustration of operation S22 of the process of the [Fig.1], for the detection of possible indications of the process of the [Fig.1]; - [Fig.7]: [Fig.7] is a schematic illustration of the second ultrasonic probe, taken perpendicular to the central axis of the piping; - [Fig.8]: [Fig.8] is a schematic illustration of operation S31 of the process of [Fig.1], for establishing the profiles of the external surface of the piping; - [Fig.9] Fig.9 is a schematic illustration of operation S32 of the process in Fig.1, for determining a height of the or each indication; and - [Fig. 10]: [Fig. 10] is a schematic illustration of the third ultrasonic probe, taken perpendicular to the central axis of the piping.
[0043] The method illustrated in [Fig.1] aims to carry out an ultrasonic inspection of a pipe 1 of the type illustrated in [Fig.2].
[0044] Piping 1 belongs to a nuclear installation such as a nuclear reactor, or to a non-nuclear industrial installation. It is intended for the flow of a liquid, a gas, or may have any other function.
[0045] The piping 1 is delimited on the outside by an external surface 3 and on the inside by an internal surface 5.
[0046] The method is particularly aimed at detecting indications on the internal surface 5 of the piping.
[0047] These indications are typically defects opening onto the internal surface 5. Each indication typically extends in a plane perpendicular to the central axis C of the central piping.
[0048] This method is particularly suitable for inspecting a section 7 of piping which has irregularities 11 at the external surface 3.
[0049] These irregularities can be, for example, an external weld bead that is not flush, a bend, a chamfer, a slope for recovery, depressions or facets in the metal near the weld, etc.
[0050] Section 7 may also have irregularities 9 at the level of the internal surface 5. This is the case in particular when section 7 corresponds to the junction zone between two straight or bent piping sections welded to each other.
[0051] These irregularities can be, for example, an internal weld bead that is not flush, a bend, a chamfer, a hollow created by a tool, etc.
[0052] The inspection procedure comprises the following steps:
[0053] - S10: Establishing an internal profile of an internal surface 5 of the section at inspect 7 of the piping 1;
[0054] - S20: Detection of possible indications in the volume and on the internal surface 5 of the section to be inspected 7 of piping 1.
[0055] Advantageously, the method further comprises a step S30 of determining the height of the or of each indication.
[0056] Here, the internal surface profile is understood to mean the mapping giving the depth of each point of said internal surface, in relation to the external surface 3 taken at the level of the section to be inspected 7, taking into account the irregularities of this external surface.
[0057] The section to be inspected 7 has an axial length between 10mm and 100mm, typically between 20mm and 80mm.
[0058] When the section to be inspected 7 has a peripheral weld, the section to be inspected axially covers the entire width of the weld plus a 20mm strip, for example, on each side of the weld bead.
[0059] During step S10, a first ultrasonic probe 13 is moved over the external surface 3 of the section to be inspected 7 to a plurality of regularly spaced determined positions.
[0060] The first ultrasonic probe 13 is moved circumferentially around the entire periphery of the section 7. It is optionally moved axially if the axial length of the section to be inspected is greater than the length of the first ultrasonic probe 13. The determined positions are distributed so as to be able to control the entire internal surface of the section to be inspected 7.
[0061] The step S10 of establishing the internal profile of the internal surface includes, at each determined position, a first operation SI 1 of determining a first external profile of the external surface 3 of the section to be inspected, and in particular of the irregularities 11 of the section 7, illustrated in [Fig.3].
[0062] This operation aims to determine the profile of the external surface 3 locally, i.e. radially under the first ultrasonic probe 13.
[0063] During this first operation SI 1, a first ultrasonic image 61 is formed by the first ultrasonic probe 13 positioned with an angle of incidence between -15° and +15° relative to a normal to the external surface 3.
[0064] The normal here is the normal to a plane tangent to the external surface at the determined position occupied by the first ultrasonic probe 13. The angle of incidence is preferably between -10° and +10°, and is typically 0°.
[0065] The first ultrasonic image 61 consists of longitudinally polarized ultrasonic waves.
[0066] During the SI 1 operation of determining the first external profile, a first ultrasonic image 61 is formed at each determined position.
[0067] It corresponds to the echoes of the incident ultrasonic signals emitted by the first ultrasonic probe 13, then reflected by the external surface 3 of the section to be inspected 7, in particular by the irregularities 11.
[0068] The first ultrasonic image 61 is recorded for analysis.
[0069] The profile 63 of the external surface 3 is determined by analyzing the first image ultrasonic 61.
[0070] The first external profile 63, which is the result of the analysis of the first ultrasonic image 61, is considered as the local profile of the external surface 3 and includes the irregularities 11 of the section 7.
[0071] Step S10 includes, at each determined position, a second operation S12 for determining the internal profile, illustrated in [Fig.4].
[0072] The result of the analysis of the first ultrasonic image is exploited so that a second ultrasonic image 65 can be formed by the first ultrasonic probe 13 taking into account the actual profile 63, of the external surface 3.
[0073] The second ultrasonic image 65 consists of longitudinally polarized ultrasonic waves.
[0074] During the S12 operation of determining the profile of the internal surface, a second ultrasonic image 65, adapted to the external profile 63, is formed at each determined position. It corresponds to the echoes of the incident ultrasonic signals emitted by the first ultrasonic probe 13, then reflected by the internal surface 5 of the section to be inspected 7, in particular by the irregularities 9.
[0075] The second ultrasonic image 65 is recorded for analysis.
[0076] The internal profile 66 of the internal surface 5 is determined by analyzing the second ultrasonic image 65 thus formed.
[0077] Typically, the first ultrasonic probe 13 is a multi-element probe.
[0078] The multi-element probe, as illustrated in [Fig.3], comprises a plurality of transmitter / receiver elements 15. Each element 15 functions as a transmitter and receiver.
[0079] The first ultrasonic probe 13 is equipped with a conformable sole 14. This conformable sole is typically a pouch, for example, filled with water. It is interposed between the transmitting / receiving elements 15 of the first ultrasonic probe and the external surface 3.
[0080] In other words, the first ultrasonic probe 13 is not directly in contact with the external surface 3, but is in contact with the external surface 3 through the conformable sole 14. The conformable sole 14 transmits the ultrasonic signals generated by the first ultrasonic probe 13 to the external surface 3.
[0081] The first ultrasonic probe 13 is driven for the formation of the first ultrasonic image 61 according to the FMC method (Full Matrix Capture, i.e. complete capture of the signals from the transmitter-receiver pairs of each of the elements of the ultrasonic probe).
[0082] The first external profile 63 is determined by analyzing the first ultrasonic image 61 obtained by the TFM (Total Focusing Method).
[0083] The FMC method and the TFM method are known and will not be described in detail here.
[0084] The analysis of the first ultrasonic image 61, allowing the external profile 63 to be established, is carried out automatically using a filtering method not described here.
[0085] The first ultrasonic probe 13 is driven for the formation of the second ultrasonic image 65 according to the FMC method.
[0086] The internal profile 66 is determined by analyzing the second ultrasonic image 65 by the TFM method.
[0087] During the second operation S12, the second ultrasonic image 65 is formed using the first external profile 63 determined in the first operation SI 1. A phase delay set corresponding to the first external profile 63 is applied to the emitting elements 15, i.e. to the elements 15 operating as emitters, so as to form a second ultrasonic image, which is coherent and usable, representing the internal profile 66.
[0088] We therefore use here the so-called adaptive TFM method, since the profile of the external surface is determined first, then used to adjust the emission parameters so as to take into account them to determine the internal profile.
[0089] The determination of the internal profile 66 makes it possible to know the nature and position of the irregularities 9 located in the internal wall 5 of the section 7. In particular, this information is necessary for the correct positioning of the probes used in the following steps S20 and S30 as well as for the correct interpretation of the ultrasonic images which will be formed in these steps for the detection, confirmation and height measurement.
[0090] Step S20 of detecting possible indications in the volume and on the internal surface 5 of the section to be inspected 7 provides that a second ultrasonic probe 17 is moved on the external surface 3 of a section 19 of the piping, adjacent to the section to be inspected 7, at a plurality of regularly spaced determined positions.
[0091] When section 7 has a weld line, the adjacent section 19 is a section without a weld line but which may possibly have an elbow, a chamfer, a slope for recovery or basins / facets.
[0092] The second ultrasonic probe 17, in a manner analogous to the first ultrasonic probe 13, is moved circumferentially all around the adjacent section 19, and / or axially along the adjacent section.
[0093] It is moved to a plurality of determined positions chosen to sweep the entire external surface of the adjacent section 19.
[0094] The determined positions of the second ultrasonic probe 17 are determined with respect to a common position reference with the first ultrasonic probe 13.
[0095] The step S20 of detecting possible indications includes, at each determined position of the second ultrasonic probe 17, a third operation S21 of determining a second profile of the external surface 3 of the adjacent section 19 (called second external profile), illustrated by [Fig.5].
[0096] This operation aims to determine the profile of the external surface 3 locally, i.e. radially under the second ultrasonic probe 17.
[0097] During this third operation S21, a third ultrasonic image 67 is formed by the second ultrasonic probe 17, positioned with an angle of incidence ai between 0° and 28°, preferably between 18° and 20°, and typically 19° relative to the normal to the external surface 3.
[0098] The normal, as illustrated in [Fig. 5], is taken perpendicular to the plane tangent to the external surface 3 at the determined position of the second ultrasonic probe 17.
[0099] The third ultrasonic image 67 consists of longitudinally polarized ultrasonic waves.
[0100] During the third operation S21, a third ultrasonic image 67 is formed at each determined position. It corresponds to the echoes of the incident ultrasonic signals emitted by the second ultrasonic probe 17, then reflected by the external surface of the section 19 adjacent to the section to be inspected 7. The third ultrasonic image 67 is recorded for analysis.
[0101] The second external profile 69, that is to say the profile of the external surface 3 at the level of the adjacent section 19, is determined by analyzing the third ultrasonic image 67.
[0102] The second external profile 69, which is the result of the analysis of the third ultrasonic image 67, is considered as the local external profile of the external surface 3, with the irregularities of the external surface of the section 19.
[0103] Step S20 includes, at each determined position, a fourth operation S22 of determining the presence of an indication located in the volume and on the internal surface 5 of the section to be inspected 7, in particular in the vicinity of the irregularities 9, illustrated in figures 6 and 7.
[0104] During the fourth operation S22, a fourth ultrasonic image 71 of the internal surface 5 of the section to be inspected 7 consisting of transversely polarized waves is formed by the second ultrasonic probe 17.
[0105] The fourth ultrasonic image 71 is formed taking into account the second external profile 69,
[0106] In other words, the result of the analysis of the third ultrasonic image 67 is exploited so that the fourth ultrasonic image 71 can be formed by the second ultrasonic probe 17 taking into account the actual external profile 69 of the external surface of the adjacent section 19.
[0107] During the fourth operation S22, a fourth ultrasonic image 71 is formed at each determined position. The fourth ultrasonic image 71 corresponds to the echoes of the incident ultrasonic signals emitted by the second ultrasonic probe 17, then reflected by the indications and by the internal surface 5 of the section to be inspected 7, in particular by the irregularities 9 and the indication 25.
[0108] The fourth ultrasonic image 71 is recorded for analysis.
[0109] Possible indications 25 are detected and their positions on the internal profile of the internal surface 5 of the section to be inspected 7 are determined using the fourth ultrasonic image 71 and the internal profile 66 previously established during the second operation S12.
[0110] The second ultrasonic probe 17 is a multi-element probe. The second ultrasonic probe 17 comprises a plurality of emitting and / or receiving elements.
[0111] In the example shown in Figures 6 and 7, the second probe 17 comprises a plurality of emitting elements 21 and a plurality of receiving elements 23 distinct from the emitting elements 21.
[0112] Elements 21 and 23 can function as both transmitters and receivers.
[0113] Elements 21 and 23 are positioned side by side. They are not in the same plane propagation but direct the emission and reception of ultrasonic waves so that the area of interest (the internal surface 5 of the section to be inspected 7, the irregularities 9 and the surroundings where the indications sought are located) is correctly insonified by the crossing of the incident and reflected ultrasonic beams induced by the angle 0.
[0114] The second ultrasonic probe 17 is equipped with a conformable sole 18. This conformable sole is typically a water pouch. It is interposed between, on the one hand, the emitting elements 21 and the receiving elements 23 of the second ultrasonic probe 17 so that these elements are acoustically isolated, and on the other hand, the external surface 3.
[0115] In other words, the second ultrasonic probe 17 is not directly in contact with the external surface 3, but is in contact with the external surface 3 through the conformable sole 18. The conformable sole 18 transmits the ultrasonic signals generated by the second ultrasonic probe 17 to the external surface 3.
[0116] During the third operation S21, the second ultrasonic probe 17 is driven to form the third ultrasonic image 67 indifferently according to the FMC or PWI (Planar Wave Imaging) method.
[0117] For example, the elements 21 are used as emitters and receivers, so that the external surface profile 69 of the section 19 determined by the operation S21 corresponds to that which is locally directly above the elements 21.
[0118] The second external profile 69 is determined by analyzing the third ultrasonic image 67 by the TFM (Total Focusing Method).
[0119] The FMC / PWI methods and the TFM method are known and will not be described in detail here.
[0120] The analysis of the third ultrasonic image 67 of the external profile 3 is carried out automatically using a filtering not described here.
[0121] During the fourth operation S22, the second ultrasonic probe 17 is driven to form the fourth ultrasonic image 71 according to the PWI (Planar Wave Imaging) method.
[0122] Typically, elements 21 are used as emitters and elements 23 as receivers.
[0123] Possible indications 25 are detected and their positions on the internal profile of the internal surface 5 of the section to be inspected 7 are determined by analyzing the fourth ultrasonic image 71 by the TFM (Total Focusing Method).
[0124] The PWI method and the TFM method are known and will not be described in detail here.
[0125] According to the PWI method, the incident ultrasonic emission comprises several ultrasonic waves emitted successively. Each incident ultrasonic wave is emitted jointly by all the emitting elements 21. Each incident ultrasonic wave forms a plane wave.
[0126] This wave extends in a plane perpendicular to the direction of propagation of the DP wave illustrated in [Fig.6].
[0127] The incident ultrasonic waves have different propagation directions from each other, forming with the normal to the external surface 3 propagation angles staggered around the principal angle of refraction ar which is typically 45°.
[0128] The propagation angle corresponds to the angle between the propagation direction DP and the normal to the plane tangent to the external surface 3 at the determined position of the probe 17.
[0129] To constitute the incident ultrasonic wave, each emitting element 21 emits an ultrasonic signal, together forming a plane wave propagating around the direction of propagation DP.
[0130] The propagation angles are regularly distributed between two extreme values, for example ar-45° and ar+45°.
[0131] The propagation angles of the different incident ultrasonic waves are separated for example by increments of 1°.
[0132] All the receiving elements 23 record the echoes of each incident emitted and reflected ultrasonic wave.
[0133] The matrix of elementary time signals corresponding to the echoes of each of the incident ultrasonic waves detected by each receiving element 23 constitutes the fourth ultrasonic image 71.
[0134] The matrix of elementary time signals is a rectangular matrix, the number of rows being equal to the number of incident ultrasonic waves emitted, and the number of columns being equal to the number of receiving elements 23.
[0135] The second external profile 69, determined at the end of operation S21, is used during operation S22 to form the fourth ultrasonic image 71 of the area of interest (the internal surface 5 of the section to be inspected 7 and in particular the area with irregularities 9 and the indications).
[0136] A phase delay set corresponding to the second external profile 69 is applied to the receiving elements 23 so as to form the fourth ultrasonic image 71 of the internal profile which is coherent and usable.
[0137] Advantageously, the fourth ultrasonic image 71 is compared to the second ultrasonic image 65, showing the internal profile 66 collected at operation S12 to properly position the indications 25 along the internal profile 66.
[0138] As illustrated in [Fig.6], during the fourth S22 operation of detecting possible indications, the indications 25 are detected by corner effect.
[0139] This means that the incident ultrasonic signal is first reflected by the internal surface 5 of the section to be inspected 7, then by the crack indication 25, before returning to the second ultrasonic probe 17. This allows obtaining a particularly intense reflected ultrasonic signal when there is an open indication or one very close to the internal surface 5.
[0140] Knowledge of the internal profile of the internal surface 5 of the section to be inspected 7, determined by operation S12, therefore makes it possible to position the indications 25 on the internal surface 5 in a particularly precise manner.
[0141] Analysis of the fourth ultrasonic image 71 also makes it possible to precisely position the open end 27 of each indication 25. The open end 27 corresponds to the end of the indication 25 through which this indication opens at the level of the internal surface 5. This makes it possible to know the depth of the end 27 relative to the external surface 3.
[0142] At step S30 of determining a height of the or each indication, a third ultrasonic probe 28 is moved to a plurality of regularly spaced determined positions on the external surface 3 of the adjacent section 19.
[0143] Alternatively, the third ultrasonic probe 28 is moved to the external surface 3 of another section 29 adjacent to the section to be inspected 7, as illustrated in [Fig. 2]. This other adjacent section 29 is located axially opposite the adjacent section 19 with respect to the section to be inspected 7.
[0144] As before, the third ultrasonic probe 28 is moved circumferentially all around the external surface 3 of the adjacent section 19 or of the other adjacent section 29, and possibly axially.
[0145] It is moved to a plurality of determined positions chosen to sweep the entire external surface of the adjacent section 19 or 29.
[0146] The determined positions of the third ultrasonic probe 28 are determined with respect to a common position reference with the first and / or second ultrasonic probe.
[0147] The step S30 of determining the height of the or each indication includes, at each determined position, a fifth operation S31 of determining a third external profile of the external surface 3 of the adjacent section 19 or 29, illustrated by [Fig.8].
[0148] This operation aims to determine the profile of the external surface 3 locally, i.e. radially under the third ultrasonic probe 28.
[0149] During this fifth operation S31, a fifth ultrasonic image 73 is formed by the third ultrasonic probe 28, positioned with an angle of incidence ai between 0° and 28°, preferably between 10° and 15°, and typically 12° relative to the normal to the external surface 3.
[0150] The normal, as illustrated in [Fig.8], is taken perpendicular to the plane tangent to the external surface 3 at the determined position of the third ultrasonic probe 28.
[0151] The fifth ultrasonic image 73 consists of longitudinally polarized ultrasonic waves.
[0152] During the fifth operation S31, a fifth ultrasonic image 73 is formed at each determined position. It corresponds to the echoes of the incident ultrasonic signals emitted by the third ultrasonic probe, then reflected by the external surface of the section 19 or 29 adjacent to the section to be inspected 7.
[0153] The fifth ultrasonic image 73 is recorded for analysis.
[0154] The third external profile 75, that is to say the profile of the external surface 3 at the level of the adjacent section 19 or 29, is determined by analyzing the fifth ultrasonic image.
[0155] The third external profile 75, which is the result of the analysis of the fifth ultrasonic image 73, is considered as the local external profile of the external surface 3, with the irregularities of the external surface of the section 19 or 29.
[0156] Step S30 includes, at each determined position, a sixth operation S32 of determining the presence of an indication located in the volume and on the internal surface 5, and of measuring the height, illustrated by figures 9 and 10.
[0157] During the sixth operation S32, a sixth ultrasonic image 77 of the internal surface 5 of the section to be inspected 7 consisting of longitudinally polarized waves is formed by the third ultrasonic probe 28, the sixth ultrasonic image 77 being formed taking into account the third external profile 75.
[0158] In other words, the sixth ultrasonic image 77 is formed by the third ultrasonic probe 28 taking into account the actual external profile 75 of the external surface of the adjacent section 19 or 29.
[0159] The second ultrasonic image 77 consists of longitudinally polarized ultrasonic waves.
[0160] During the sixth operation S32, a sixth ultrasonic image 77, adapted to the external profile 75, is formed at each determined position. It corresponds to the echoes of the incident ultrasonic signals emitted by the third ultrasonic probe, then reflected by the indications and by the internal surface 5 of the section to be inspected 7, as well as by diffraction phenomena, in particular diffraction by the irregularities 9 and the or each indication 25.
[0161] The sixth ultrasonic image 77 is recorded for analysis.
[0162] Possible indications 25 are detected and the height of the or each indication 25 is determined using the sixth ultrasonic image 77 and possibly the first internal profile 66 previously established during the second operation S12.
[0163] The presence of the indication and the height measurement are determined by analyzing the sixth ultrasonic image 77 formed.
[0164] The first internal profile 66 can be used to confirm the analysis.
[0165] Typically, the third ultrasonic probe 28 is a multi-element probe. It is of the same type as the second ultrasonic probe 17.
[0166] In other words, it comprises a plurality of emitting and / or receiving elements. For example, the third ultrasonic probe comprises a plurality of emitting elements 31, and a plurality of receiving elements 33 distinct from the emitting elements 31.
[0167] Elements 31 and 33 can function as both transmitters and receivers.
[0168] Elements 31 and 33 are positioned side by side. They are not in the same propagation plane but direct the emission and reception of ultrasonic waves so that the area of interest (the internal surface 5, the irregularities 9 and the surroundings where the indications sought are located) is correctly insonified by the crossing of the incident and reflected ultrasonic beams induced by the angle 0.
[0169] The third ultrasonic probe 28 is equipped with a conformable sole 30. This conformable sole is typically a pouch, for example, filled with water. It is interposed between, on the one hand, the emitting elements 31 and the receiving elements 33 of the third ultrasonic probe 28 so that these elements are acoustically isolated, and on the other hand, the external surface 3.
[0170] In other words, the third ultrasonic probe 28 is not directly in contact with the external surface 3, but is in contact with the external surface 3 through the conformable sole 30. The conformable sole 30 transmits the ultrasonic signals generated by the third ultrasonic probe 28 to the external surface 3.
[0171] During the fifth operation S31, the third ultrasonic probe 28 is driven to form the fifth ultrasonic image 73 indifferently according to the FMC or PWI (Planar Wave Imaging) method.
[0172] For example, the elements 31 are used as emitters and receivers, so that the external surface profile 75 of the section 19 or 29 corresponds to that which is locally directly above the elements 31.
[0173] The third external profile 75 is determined by analyzing the fifth ultrasonic image 73 by the TFM method.
[0174] The FMC / PWI methods and the TFM method are known and will not be described in detail here.
[0175] The analysis of the fifth ultrasonic image 73 is carried out automatically using a filtering method not described here.
[0176] During the sixth operation S32, the third ultrasonic probe 28 is driven to form the sixth ultrasonic image 77 according to the PWI (Planar Wave Imaging) method.
[0177] For example, elements 31 are used as emitters and elements 33 as receivers.
[0178] Possible indications 25 are detected and the height of the or each indication 25 is determined by analyzing the sixth ultrasonic image 71 by the TFM method.
[0179] The PWI method and the TFM method are known and will not be described in detail here.
[0180] According to the PWI method, the incident ultrasonic emission comprises several ultrasonic waves emitted successively. Each incident ultrasonic wave is emitted jointly by all the emitting elements 31. Each incident ultrasonic wave forms a plane wave.
[0181] This wave extends in a plane perpendicular to the direction of propagation of the DP wave illustrated in [Fig.8].
[0182] The incident ultrasonic waves have different propagation directions from each other, forming angles with the normal to the external surface 3 propagation patterns are staggered around the principal angle of refraction ar, which is typically 55°.
[0183] The propagation angle corresponds to the angle between the propagation direction DP and the normal to the plane tangent to the external surface 3 at the determined position of the probe 28.
[0184] To constitute the incident ultrasonic wave, each emitting element 31 emits an ultrasonic signal, together forming a plane wave propagating along the propagation direction DP.
[0185] The propagation angles are regularly distributed between two extreme values, for example ar-55° and ar+35°.
[0186] The propagation angles of the different incident ultrasonic waves are separated, for example, by increments of 1°.
[0187] All the receiving elements 33 record the echoes of each incident emitted and reflected ultrasonic wave.
[0188] The matrix of elementary time signals corresponding to the echoes of each of the incident ultrasonic waves detected by each receiving element 33 constitutes the sixth ultrasonic image 77.
[0189] The matrix of elementary time signals is a rectangular matrix, the number of rows being equal to the number of incident ultrasonic waves emitted, and the number of columns being equal to the number of receiving elements 33.
[0190] The third external profile 75 determined at the end of operation S31 is used during operation S32 to form the sixth ultrasonic image 77 of the area of interest (the internal surface 5 of the section 7 and in particular the surroundings of the area with irregularities 9 and the indications).
[0191] A phase delay set corresponding to the third external profile 75 is applied to the receiving elements 33 so as to form an image 77 of the internal profile which is coherent and usable.
[0192] Possible indications 25 are detected, confirmed, and their position on the profile of the internal surface 5 of the section to be analyzed 7 are determined, by analyzing the sixth ultrasonic image 77.
[0193] Advantageously, the sixth ultrasonic image 77 is compared to the second ultrasonic image 65 showing the internal profile 66, collected at operation S12.
[0194] Typically, the height of each indication 25 is determined at step S30.
[0195] More specifically, the depth at which the closed end 35 of the or each indication 25 is located is determined in the step of determining the height of the or each indication S30. The depth of the open end 27 of the or each indication 25, as explained above, is determined in the step of detecting possible indications S20.
[0196] Knowing the depth of the open end 27 and the depth of the closed end 35, it is possible to determine the height of each indication 25, this being equal to the simple difference between the depth of the open end 27 and the depth of the closed end 35.
[0197] Advantageously, during the sixth operation S32, the third ultrasonic probe 28 forms the sixth ultrasonic image by emission of incident ultrasonic waves having a wavelength chosen to cause diffraction of said incident ultrasonic waves by the or each indication 25.
[0198] Typically, the second ultrasonic probe 17 and the third ultrasonic probe 28 generate ultrasonic waves of the same frequency. The wavelength of the ultrasonic signal incident with the third probe 28 is greater than the wavelength of the ultrasonic signal incident with the second probe 17 due to the use of longitudinal waves rather than transverse waves.
[0199] Due to the wavelength and the incidence of the ultrasonic waves on the indications, a diffraction phenomenon is generated, i.e. a spherical ultrasonic wave is re-emitted by the closed end 35 of the indication 25.
[0200] This diffraction makes it possible to determine precisely the depth of the closed end 35.
[0201] The operation of determining the profile of the external surface 3 of the section to be inspected 7 is made possible for the probe 13 (respectively for probes 17 and 28) in particular due to the use of the conformable sole 14 (respectively for conformable soles 18 and 30), which allows the ultrasonic probe to be moved away from the external surface 3.
[0202] This again allows the delay laws to be adapted to the emission and / or reception. In particular, this allows for a more precise calculation of the time of flight of each reflected ultrasonic wave from the point of reflection to each receiving element 15 (reversely 23 and 33).
[0203] According to an example embodiment, the movements of the probes are organized in the following manner.
[0204] At step S10, a single complete rotation of the pipe is performed. The probe 13 (with combined emission and reception) is positioned on the weld axis directly over the external surface irregularities 11 3. The first ultrasonic image 61 obtained at the measurement point is processed in real time: after filtering, the first resulting external profile 63 is used to adapt the emission delay laws and form the second ultrasonic image 65 of the internal profile, which is corrected for external surface effects. This process is carried out at each measurement point along the displacement around the pipe using this technique called ATFM (TFM / FMC with emission and / or reception adaptation).
[0205] In steps S20 and S30, similarly, only one complete turn is carried out. To inspect both sides of the weld (adjacent sides 19 and 29), the inspection must be carried out on one side and then the other, i.e., two successive rotations are required.
[0206] In certain cases, several rotations are necessary with varying distances from the axis of the section 7 to be inspected.
[0207] The ultrasonic probes 17 and 28 have separate transmitting and receiving mechanisms. As in step S10, an ultrasonic image 67, 73 of the external profile is first acquired, this image being used in real time to form an image of the internal profile corrected for the effects of the external surface.
[0208] The technique differs from that used in step S10. The external profile image is acquired either in TFM / FMC or TFM / PWI from elements 21 and 31 only, and always in longitudinal waves. This image represents the external profile and irregularities seen by one part of the probe (the emission). The external profile and irregularities for the other part of the probe (elements 23 and 33) are considered identical to those measured for elements 21 and 31. Filtering the first image obtained yields the external profile, which is used only to correct the recorded signals to create the ultrasonic image of the internal surface. Therefore, adaptation is performed only at the reception stage. This allows for faster inspection rates. Ultrasound image 71 is obtained in transverse waves (second probe) and ultrasonic image 77 in longitudinal waves (third probe).
[0209] According to one embodiment, the inspection is carried out with second and third probes 17 and 28 equipped with elements functioning both as transmitter and receiver, like the first probe 13. It is possible to use the so-called ATFM functionality on this type of probe, provided that the probe offers sufficient sensitivity.
[0210] Furthermore, it would also be possible for the second probe 17 to carry out the inspection from the other section 29.
[0211] The invention also relates to an ultrasonic inspection assembly 36, shown in [Fig.2].
[0212] The inspection assembly 36 is specially designed to implement the inspection method of the invention. Conversely, the inspection method is specially designed to be implemented by the inspection assembly 36.
[0213] Inspection assembly 36 comprises:
[0214] - a first carrier 37, fixed to the piping 1;
[0215] - a first ultrasonic probe 13 intended for establishing a profile of a internal surface 5 of a section to be inspected 7 of the piping;
[0216] - a first link 39 from the first ultrasonic probe 13 to the first carrier 37, adapted to circumferentially move the first ultrasonic probe 13 to a plurality of regularly spaced determined positions on an external surface 3 of the section to be inspected 7;
[0217] - a first controller 41 configured to perform, at each determined position, a first operation SI 1 of determining a first external profile 63 of the external surface 3 of the section to be inspected 7 and a second operation S12 of determining said internal profile 66 of the internal surface 5, during the first operation SU a first ultrasonic image 61 consisting of longitudinally polarized waves being formed by the first ultrasonic probe 13 positioned with an angle of incidence between -15° and +15° with respect to a normal to said external surface 3, the first controller 41 being configured to determine the first external profile 63 by analyzing the first ultrasonic image 61, during the second operation S12 a second ultrasonic image 65 consisting of longitudinally polarized waves being formed by the first ultrasonic probe 13 positioned with an angle of incidence between -15° and +15° with respect to a normal to said external surface 3,the second ultrasonic image 65 being formed taking into account the first external profile 63, the first controller 41 being configured to determine the internal profile 66 by analyzing the second ultrasonic image 65.
[0218] The first carrier 37 is of any type adapted to ensure the movement of the first ultrasonic probe 13. For example, it comprises a frame 39 rigidly fixed to the piping 1, a carrier structure 42, a link 43 of the carrier structure 42 to the frame 39 configured to allow the movement of the carrier structure 42 circumferentially around the piping, and a link 45 of the first ultrasonic probe 13 to the carrier structure 42 configured to allow the movement of the first ultrasonic probe 13 axially along the carrier structure 42.
[0219] Alternatively, the frame 39 is movable relative to the piping 1.
[0220] The load-bearing structure 42 is, for example, an axially extending beam.
[0221] Inspection set 36 also includes:
[0222] - a second ultrasonic probe 17 intended for the detection of possible indications in the volume and on the internal surface 5 of the section to be inspected 7;
[0223] - a second carrier 47, adapted to move the second ultrasonic probe 17 on the external surface 3 of a section 19 adjacent to the section to be inspected 7;
[0224] - a second controller 49 configured to perform, at each determined position, a third operation S21 to determine a second external profile 69 of the external surface 3 of the adjacent section 19 and a fourth operation S22 to detect any indications in the volume and on the internal surface 5 of the section to be inspected 7, during the third operation S21 a third ultrasonic image 67 consisting of longitudinally polarized waves being formed by the second ultrasonic probe 17 positioned with an angle of incidence between 0° and 28° relative to a normal to said external surface 3, the second controller 49 being configured to determine the second external profile 69 by analyzing the third ultrasonic image 67, during the fourth operation S22 a fourth ultrasonic image 71 of the internal surface 5 of the section to be inspected 7 consisting of transversely polarized waves being formed by the second ultrasonic probe 17, the fourth ultrasonic image 71 being formed taking into account the second external profile 69, the second controller 49 being configured to detect any indications 25 and determine their positions on the internal profile of the internal surface 5 of the section to be inspected 7 using the fourth ultrasonic image 71 and the internal profile 66 previously established during the second operation S12.
[0225] Typically, the inspection assembly 36 further comprises:
[0226] - a third ultrasonic probe 28 intended for determining a height of each indication;
[0227] - a third carrier 50 adapted to move the third ultrasonic probe 28 to a plurality of regularly spaced determined positions on the external surface 3 of the adjacent section 19 or on the external surface of another section 29 adjacent to the section to be inspected 7;
[0228] - a third controller 51 configured to perform, at each determined position, a fifth operation S31 of determining a third external profile 75 of the external surface 3 of the adjacent section 19 or of the other adjacent section 29 and a sixth operation S32 of determining the presence of indication and height measurement, during the fifth operation S31 a fifth ultrasonic image 73 consisting of longitudinally polarized ultrasonic waves being formed by the third ultrasonic probe 28 positioned with an angle of incidence between 0° and 28° with respect to a normal to said external surface 3, the third controller 51 being configured to determine the third external profile 75 by analyzing the fifth ultrasonic image 75, during the sixth operation S32 a sixth ultrasonic image 77 of the internal surface 5 of the section to be inspected 7 consisting of longitudinally polarized waves being formed by the third ultrasonic probe 28,the sixth ultrasonic image 77 being formed taking into account the third external profile 75, the third controller 51 configured to detect any indications 25 and determine the height of the or each indication 25 using the sixth ultrasonic image 77 and the internal profile 66 previously established during the second operation S12. ,
[0229] The first ultrasonic probe 13 is as described above. The conformable insole 14 is interposed between the first ultrasonic probe 13 and the external surface 3.
[0230] The first controller 41 is a computing device. It is configured to drive the first ultrasonic probe 13 in transmission and reception as described above. It is also configured to analyze the first reflected ultrasonic signal as described above.
[0231] Preferably, the first controller 41 is configured to implement, at each determined position of the first ultrasonic probe 13, the SI 1 operation of determining the profile of the external surface of the section to be inspected 7 described above.
[0232] The second ultrasonic probe 17 is as described above. The conformable insole 18 is interposed between the second ultrasonic probe 17 and the external surface 3.
[0233] The second carrier 47 typically consists of the first carrier 37. In other words, the carrier 37 is intended to jointly move the first probe 13 and the second ultrasonic probe 17.
[0234] Alternatively, the second bearer 47 is distinct from the first bearer 37. In this case, it is constituted in the same way as the first bearer 37.
[0235] The second controller 49 is a computing device. It is configured to drive the second ultrasonic probe 17 in transmission and reception as described above. It is also configured to analyze the second reflected ultrasonic signal as described above.
[0236] The second controller 49 is preferably configured to implement, at each determined position of the second ultrasonic probe 17, the operation S12 of determining the profile of the external surface 3 of the adjacent section 19, as described above.
[0237] The third ultrasonic probe 28 is as described above. The conformable insole 30 is interposed between the third ultrasonic probe 28 and the external surface 3.
[0238] The third carrier 50 is typically made up of the first carrier 37. In other words, the carrier 37 is configured to move the third ultrasonic probe 28 jointly with the first ultrasonic probe 13.
[0239] Preferably, the carrier 37 is configured to move the first, second and third ultrasonic probes 13, 17, 28 together.
[0240] Alternatively, the second and third carriers (47 and 50) are separate from the first carrier 37 and are dedicated solely to the second and third ultrasonic probes (17 and 29). In this case, they are constituted like the first carrier 37.
[0241] The third controller 51 is a computing device. It is configured to drive the third ultrasonic probe 28 in transmission and reception as described above. It is also configured to analyze the third reflected and diffracted ultrasonic signal as described above.
[0242] The third controller 51 is preferably configured to implement, at each determined position of the third ultrasonic probe 28, the operation S31 of determining the profile of the external surface 3 of the adjacent section 19 or of the other adjacent section 29 described above.
Claims
1. Demands Ultrasonic inspection method for a pipe (1), the method comprising the following steps: - S10: establishment of an internal profile (66) of an internal surface (5) of a section to be inspected (7) of the piping (1), a first ultrasonic probe (13) being moved on an external surface (3) of said section to be inspected at a plurality of regularly spaced determined positions, the step of establishing said internal profile of the internal surface (5) comprising, at each determined position, a first operation (SI 1) of determining a first external profile (63) of the external surface (3) of the section to be inspected (7) and a second operation (S 12) of determining said internal profile (66) of the internal surface (5), during the first operation (SI 1) a first ultrasonic image (61) consisting of longitudinally polarized waves being formed by the first ultrasonic probe (13) positioned with an angle of incidence between -15° and +15° with respect to a normal to said external surface (3),the first external profile (63) being determined by analyzing the first ultrasonic image (61), during the second operation (S 12) a second ultrasonic image (65) consisting of longitudinally polarized waves being formed by the first ultrasonic probe (13) positioned with an angle of incidence between -15° and +15° with respect to a normal to said external surface (3), the second ultrasonic image (65) being formed taking into account the first external profile (63), the internal profile (66) being determined by analyzing the second ultrasonic image (65); - S20: detection of possible indications (25) in the volume and on the internal surface (5) of the section to be inspected (7) of the piping (1), a second ultrasonic probe (17) being moved on an external surface (3) of a section (19) adjacent to said section to be inspected (7) at a plurality of regularly spaced determined positions, the step of detecting possible indications (25) comprising, at each determined position, a third operation (S21) of determining a second external profile (69) of the external surface (3) of the adjacent section (19) and a fourth operation (S22) of detecting possible indications, during the third operation (S21) a third ultrasonic image (67) consisting of waves longitudinally polarized being formed by the second ultrasonic probe (17) positioned with an angle of incidence between 0° and 28° with respect to a normal to said external surface (3), the second external profile (69) being determined by analyzing the third ultrasonic image (67), during the fourth operation (S22) a fourth ultrasonic image (71) of the internal surface (5) of the section to be inspected (7) consisting of transversely polarized waves being formed by the second ultrasonic probe (17), the fourth ultrasonic image (71) being formed taking into account the second external profile (69), the possible indications (25) being detected and their positions on the internal profile of the internal surface (5) of the section to be inspected (7) being determined using the fourth ultrasonic image (71) and the internal profile (66) previously established during the second operation (S12).
2. An inspection method according to claim 1, wherein the first ultrasonic probe (13) is a multi-element probe comprising a plurality of transmitter / receiver elements (15) operating both as a transmitter and as a receiver.
3. Inspection method according to claim 2, wherein the second ultrasonic image (65) is formed taking into account the first external profile (63) by applying to the emitting elements (15) a set of phase delays corresponding to the first external profile (63).
4. Inspection method according to claim 2 or 3, wherein the first ultrasonic probe (13) is driven for the formation of the first ultrasonic image (61) according to the FMC method, the first external profile (63) being determined by analyzing the first ultrasonic image (61) by the TFM method.
5. An inspection method according to any one of claims 2 to 4, wherein the first ultrasonic probe (13) is driven to form the second ultrasonic image (65) according to the FMC method, the internal profile (66) being determined by analyzing the second ultrasonic image (65) by the TFM method.
6. An inspection method according to claim 1 or 2, wherein the second ultrasonic probe (17) is a multi-element probe comprising a plurality of transmitting / receiving elements (21 / 23) operating both as transmitters and receivers, or comprising a plurality of emitting elements (21) and a plurality of receiving elements (23) distinct from the emitting elements (21).
7. Inspection method according to claim 6, wherein the fourth ultrasonic image (71) is formed taking into account the second external profile (69) by applying to the receiving elements (23) a set of phase delays corresponding to the second external profile (69).
8. Inspection method according to claim 6 or 7, wherein the second ultrasonic probe (17) is driven for the formation of the third ultrasonic image (67) according to the FMC or PWI method, the second external profile (69) being determined by analyzing the third ultrasonic image (67) by the TFM method.
9. An inspection method according to any one of claims 6 to 8, wherein the second ultrasonic probe (17) is driven to form the fourth ultrasonic image (71) according to the PWI method, any indications (25) being detected and their positions on the internal profile of the internal surface (5) of the section to be inspected (7) being determined by analyzing the fourth ultrasonic image (71) by the TFM method.
10. An inspection method according to any one of the preceding claims, wherein at the stage of detecting possible indications (S20), the indications (25) are detected by wedge effect.
11. An inspection method according to any one of the preceding claims, wherein the method comprises a step (S30) of determining a height of the or each indication (25), a third ultrasonic probe (28) being moved to a plurality of regularly spaced determined positions on the external surface (3) of said adjacent section (19), or on an external surface (3) of another adjacent section (29) of said section to be inspected (7), the step (S30) of determining a height of the or each indication (25) comprising, at each determined position, a fifth operation (S31) of determining a third external profile (75) of the external surface (3) of the adjacent section (19) or of the other adjacent section (29) and a sixth operation (S32) of determining the presence of indication and measuring height,during the fifth operation (S31) a fifth ultrasonic image (73) consisting of longitudinally polarized ultrasonic waves being formed by the third ultrasonic probe (28) positioned with, an angle of incidence between 0° and 28° with respect to a normal to said external surface (3), the third external profile (75) being determined by analyzing the fifth ultrasonic image (75), during the sixth operation (S32) a sixth ultrasonic image (77) of the internal surface (5) of the section to be inspected (7) consisting of longitudinally polarized waves being formed by the third ultrasonic probe (28), the sixth ultrasonic image (77) being formed taking into account the third external profile (75), the possible indications (25) being detected and the height of the or each indication (25) being determined using the sixth ultrasonic image (77) and possibly the first internal profile (66) previously established during the second operation (S12).
12. An inspection method according to claim 11, wherein the third ultrasonic probe (28) is a multi-element probe comprising a plurality of transmitting / receiving elements (31 / 33) operating both as a transmitter and a receiver, or comprising a plurality of transmitting elements (31) and a plurality of receiving elements (33) distinct from the transmitting elements (31).
13. Inspection method according to claim 12, wherein the sixth ultrasonic image (77) is formed taking into account the third external profile (75) by applying to the receiving elements (33) a set of phase delays corresponding to the third external profile (75).
14. Inspection method according to claim 12 or 13, wherein the third ultrasonic probe (28) is driven for the formation of the fifth ultrasonic image (73) according to the FMC or PWI method, the third external profile (75) being determined by analyzing the fifth ultrasonic image (73) by the TFM method.
15. An inspection method according to any one of claims 12 to 14, wherein the third ultrasonic probe (28) is driven to form the sixth ultrasonic image (77) according to the TWI method, any indications (25) being detected and the height of the or each indication (25) being determined by analyzing the sixth ultrasonic image (71) by the TFM method.
16. An inspection method according to any one of claims 11 or 15, wherein a depth of an open end (27) of the or each indication (25) at the level of the internal surface (5) of the section to be inspected (7) is determined at the detection step possible indications (S20), a depth of a closed end (35) of the or each indication (25) being determined at the step of determining a height of the or each indication (S30).
17. An inspection method according to any one of claims 11 to 16, wherein during the sixth operation (S32), the third ultrasonic probe (28) forms the sixth ultrasonic image by emitting incident ultrasonic waves having a wavelength chosen to cause diffraction of said incident ultrasonic waves by the or each indication (25).
18. Ultrasonic pipe inspection assembly (36), the assembly comprising: - a first ultrasonic probe (13) intended for establishing an internal profile of an internal surface (5) of a section to be inspected (7) of the pipe (1); - a first carrier (37), adapted to move the first ultrasonic probe (13) to a plurality of regularly spaced determined positions on an external surface (3) of said section to be inspected (7); - a first controller (41) configured to perform, at each determined position, a first operation (SU) of determining a first external profile (63) of the external surface (3) of the section to be inspected (7) and a second operation (S 12) of determining said internal profile (66) of the internal surface (5),During the first operation (SU), a first ultrasonic image (61) consisting of longitudinally polarized waves is formed by the first ultrasonic probe (13) positioned at an angle of incidence between -15° and +15° with respect to a normal to said external surface (3), the first controller (41) being configured to determine the first external profile (63) by analyzing the first ultrasonic image (61); during the second operation (S 12), a second ultrasonic image (65) consisting of longitudinally polarized waves is formed by the first ultrasonic probe (13) positioned at an angle of incidence between -15° and +15° with respect to a normal to said external surface (3), the second ultrasonic image (65) being formed taking into account the first external profile (63), the first controller (41) being configured to determine the internal profile (66) by analyzing the second ultrasonic image (65);
19. - a second ultrasonic probe (17) intended for the detection of possible indications (25) in the volume and on the internal surface (5) of the section to be inspected (7) of the piping (1); - a second carrier (47), adapted to move the second ultrasonic probe (17) to a plurality of regularly spaced determined positions on an external surface (3) of a section (19) adjacent to said section to be inspected (7); - a second controller (49) configured to perform, at each determined position, a third operation (S21) of determining a second external profile (69) of the external surface (3) of the adjacent section (19) and a fourth operation (S22) of detecting possible indications in the volume and on the internal surface (5) of the section to be inspected (7), during the third operation (S21) a third ultrasonic image (67) consisting of longitudinally polarized waves being formed by the second ultrasonic probe (17) positioned with an angle of incidence between 0° and 28° with respect to a normal to said external surface (3), the second controller (49) being configured to determine the second external profile (69) by analyzing the third ultrasonic image (67),During the fourth operation (S22), a fourth ultrasonic image (71) of the internal surface (5) of the section to be inspected (7), consisting of transversely polarized waves, is formed by the second ultrasonic probe (17). The fourth ultrasonic image (71) is formed taking into account the second external profile (69). The second controller (49) is configured to detect any indications (25) and determine their positions on the internal profile of the internal surface (5) of the section to be inspected (7) using the fourth ultrasonic image (71) and the internal profile (66) previously established during the second operation (S12). Inspection assembly according to claim 18, wherein the assembly (36) comprises: - a third ultrasonic probe (28) intended for determining a height of the or each indication (25); - a third carrier (50), adapted to move the third ultrasonic probe (28) to a plurality of regularly spaced determined positions on the external surface (3) of said adjacent section (19), or on an external surface (3) of another adjacent section (29) of said section to be inspected (7), - a third controller (51) configured to perform, at each determined position, a fifth operation (S31) of determining a third external profile (75) of the external surface (3) of the adjacent section (19) or of the other adjacent section (29) and a sixth operation (S32) of determining the presence of an indication and a height measurement, during the fifth operation (S31) a fifth ultrasonic image (73) consisting of longitudinally polarized ultrasonic waves being formed by the third ultrasonic probe (28) positioned with an angle of incidence between 0° and 28° with respect to a normal to said external surface (3), the third controller (51) being configured to determine the third external profile (75) by analyzing the fifth ultrasonic image (75),During the sixth operation (S32), a sixth ultrasonic image (77) of the internal surface (5) of the section to be inspected (7), consisting of longitudinally polarized waves, is formed by the third ultrasonic probe (28). The sixth ultrasonic image (77) is formed taking into account the third external profile (75). The third controller (51) is configured to detect any indications (25) and determine the height of the indication(s) (25) using the sixth ultrasonic image (77) and the internal profile (66) previously established during the second operation (S12).