Développement de sondes courants de Foucault matricielles pour le contrôle de composants nucléaires complexes
Titre du congrès :6th International Conference on NDE in Relation to Structural Integrity for Nuclear and Pressurised Components
Ville du congrès :Budapest
Date du congrès :08/10/2007
The inspection of materials used in nuclear industry is an important issue for the safety of components exposed to stress or/and corrosion. In this context, the CEA LIST has developed two kinds of advanced eddy current probes:
-Flexible array probes, based on micro-coils for the detection of surface or subsurface flaws located in complex shaped components,
-Giant Magneto-Resistance probes for the detection of deeply embedded flaws.
This paper presents recent developments done in the framework of a joined R&D program between CEA and the French Institute for Radiological Protection and Nuclear Safety (IRSN). Three EC probes have been developed for the detection of surface and deeply embedded flaws. The first paragraph deals with the detection of surface flaws. First, a flexible array probe is presented and a comparison with a classical coil reveals the advantages of the probe in terms of spatial resolution. Then a second flexible probe is presented. It gives good results in the detection of subsurface longitudinal and transversal notches located in a planar mock-up representative of the roll-up transition of a steam generator tube. The second paragraph describes the detection of deeply embedded flaws using a Giant Magneto-Resistance sensor. The tested component is made of stainless steel and includes important variations of the ferrite rate. In spite of the intrinsic noise of the material, all flaws are well detected.