INVESTIGADORES
VICENTE ALVAREZ Miguel Angel
artículos
Título:
Typical Zirconium Alloys Microstructures in Nuclear Components
Autor/es:
A.V. FLORES; A.G. GOMEZ; G.A. JUAREZ; N. LOUREIRO; R. I. SAMPER; J. R. SANTISTEBAN; M. A. VICENTE ALVAREZ; A. TOLLEY; A. CONDÓ; R. D. BIANCHI; A. D. BANCHIK; P. VIZCAINO
Revista:
PRAKTISCHE METALLOGRAPHIE
Editorial:
CARL HANSER VERLAG
Referencias:
Lugar: Berlin, Germany; Año: 2014 vol. 51 p. 656 - 674
ISSN:
0032-678X
Resumen:
The different microstructures typically found in nuclear
components made of zirconium alloys are discussed in this paper. These
include material in a variety of thermo-mechanical conditions, e. g.,
cold rolled, stress relieved, recrystallized, welded, biphasic, together
with minority second phases belonging to the original material or
incorporated due to in-service conditions. The anisotropic crystalline
structure of zirconium is exploited in microscopical observations by
means of polarizer filters that enhance the contrast between different
grains, and greatly aid the identification in most microstructures. Most
microstructural variations across a wide range of length-scales, such
as those produced by welding processes, can be effectively resolved by
traditional optical microscopy (OM). However, some finer microstructures
like those found in CANDU1 (CANada Deuterium Uranium) reactor pressure tube material, or some minority second phase particles like the Zr(Fe, Cr)2
precipitates in Zircaloy-4 cannot be completely resolved by this
technique. Thus, scanning electron microscopy (SEM), and transmission
electron microscopy (TEM) are required in such cases. For SEM
observations we show the valuable issue of the scale in specific
microstructural studies, which allows quantifying microstructural
parameters using image analysis. For TEM observations, we have greatly
benefited from the electron diffraction diagrams, which have allowed us
to investigate the crystalline structure of irradiated second phase
particles, which would remain unnoticed to both, OM or SEM observations.