Processing of β-treated Zircaloy-4 by warm compressions along three orthogonal axes

摘要: The purpose of this work is to refine the grains Zircaloy-4 before it processed into cladding tubes containing nuclear fuel. This raises question mechanisms by which Widmanstatten lamellae inherited from β-quenching transform smaller crystallites. With a view accelerate transformation, strain steps compression along three orthogonal axes were performed in upper α-range (i.e. 550–810 °C). effects temperature, size steps, rate and number cycles compressions investigated. All have direct influence on mechanical behavior, global texture microstructural evolution. latter was studied mostly electron backscattering diffraction. best conditions break initial found at high (4 s−1): small recrystallized around 10 μm obtained after one cycle 750 °C. But moderate rates (0.1 s−1), good results also reached two 650 °C. globularization are different both cases: first, germination new prevails while second, progressive evolution subgrains observed. Some consequences heat treatments briefly described, pointing out sensitivity undesirable grain growth. conclusion emphasizes interest multiaxial forging thermomechanical treatment hexagonal alloys.