ESTUDIO DE RELACIÓN ENTRE MICROESTRUCTURA Y TEXTURA CRISTALOGRÁFICA FINAL EN TRANSFORMACIÓN DE FASE BETA-ALFA EN Zry-4

VICENTE ALVAREZ, M.A.; BARUJ, A.; MOYA RIFFO, A.; LIMANDRI S.; SANTISTEBAN, J.R.; VOGEL, S.C.

Córdoba

Congreso; 16 Congreso Internacional de Metalurgia y Materiales SAM-CONAMET; 2016

Zirconium alloys are widely used in the nuclear industry [1] because it has excellent corrosion response,high mechanical strength and at the same time is almost transparent to neutrons and therefore does not affect the dynamics of the nuclear reaction occurring in the reactor core. Pure Zirconium and its alloys have a low temperature equilibrium phase with a hexagonal closed package crystal structure (hcp), which has a marked anisotropy of properties. The preferential orientation of those crystals is developed on the manufacturing process of the pieces [2]. So, a study of the crystallographic texture is needed to define the final properties of the material. In other situations these parts can experience a phase transformation, as on welding (pod-cap case, containers reflectors), heat-treated sheets, spent fuel rods after an accident of loss of coolant type (LOCA), etc. where the material reach temperatures over ~860ºc to the high temperature phase with a body center cubic structure (bcc). On this work we present a study on Zry-4 samples treated under controlled conditions, at temperatures of 1000ºC with measurement in situ of the texture, using neutron diffraction experiments with the ?HIPPO? (High Pressure Preferred Orientation) instrument on the Neutron Science Center at Los Alamos National Laboratory, USA. and then ex-situ measurement with EBSD orientation maps. To correlate the microstructure with the crystallographic texture, we made experimentswith different cooling rates from different max temperatures, based on information from a previous work of a weld on the same material [3].