Method and device for ultrasound inspection of welds, particularly welds of blades on the disk of a bladed disk

1. A method for testing element welds on a body, the body and the elements that are welded to the body forming a single-piece assembly, the method comprising: equipping a free end of a poly-articulated robot with an ultrasound probe, fitted with an ultrasonic multi-element array transducer, the elements of said transducer being arranged in a checkerboard layout; inserting the ultrasound probe into a space between two adjacent elements of the single-piece assembly, facing a welded joint, corresponding to one of the two elements for which a weld is to be tested; moving the ultrasound probe along three-dimensional trajectories along a profile of the element for which the weld is to be tested; performing at least two sectorial electronic scannings in at least two non-parallel testing planes which are approximately orthogonal for each of a plurality of acquisition points along each of the three-dimensional trajectories; processing the resulting sectorial electronic scans to compensate for an effect of deviations of an ultrasound beam output by the ultrasonic multi-element array transducer due to an interaction of the ultrasonic multi-element array transducer with a surface of the welds between the body and the elements; and further processing ultrasound signals output by the transducer in order to test the welds.

2. The method according to claim 1 , wherein the test is a test by transverse ultrasound waves.

3. The method according to claim 2 , wherein testing is made by working in full-skip and in half-skip.

4. The method according to claim 3 , further comprising testing the welded joint of each element by performing a first pass to test the welded joint in half-skip and a second pass to test the welded joint in full-skip.

5. The method according to claim 4 , further comprising using the poly-articulated robot to follow the profile along each element, at a first constant distance from a corresponding joint plane and at a second constant distance from the corresponding joint plane different from the first distance.

6. The method according to claim 1 , wherein the ultrasound probe is a beveled probe, adapted to the space between the two adjacent elements of the single-piece assembly.

7. The method according to claim 1 , further comprising:

using a data acquisition software,

entering characteristics of the transducer, characteristics of the single-piece assembly, and a test configuration in the data acquisition software,

calculating delay laws for the transducer,

making a calibration on a reference part,

adjusting intervals of numeric values of test parameters,

defining a test sequence, and

acquiring signals output by the transducer and analyzing the signals to test the welds.

8. The method according to claim 1 , wherein the elements are composed of blades, and the body includes a disk part of an assembly forming a turbomachine blisk, the test being a test of the welds of the blades on the disk part of the blisk.

9. The method according to claim 1 , wherein the sectorial electronic scanning in at least two approximately orthogonal testing planes is performed in a single pass for each of the plurality of acquisition points.

10. A device for testing welds of elements on a body, the body and the elements welded to the body forming a single-piece assembly, the device comprising: a poly-articulated robot, capable of making three-dimensional trajectories;

an ultrasound probe, fitted with an ultrasonic multi-element array transducer, the elements of said transducer being arranged in a checkerboard layout, the probe being fitted on the poly-articulated robot to make an ultrasound test in a space between two adjacent elements of the single-piece assembly, wherein the ultrasound probe is arranged for performing at least two sectorial electronic scannings in at least two non-parallel testing planes which are approximately orthogonal for each of a plurality of acquisition points along a three-dimensional trajectory; and an electronic signal processing device configured to process the sectorial electronic scans to compensate for an effect of deviations of an ultrasound beam output by the ultrasonic multi-element array transducer due to an interaction of the ultrasonic multi-element array transducer with a surface of the welds between the body and the elements and further configured to process signals output by the ultrasonic multi-element array transducer in order to test the welds.

11. The device according to claim 10 , wherein the poly-articulated robot and the ultrasound probe are arranged for performing the sectorial electronic scanning in at least two approximately orthogonal testing planes in a single pass for each of the plurality of acquisition points.