Mechanical properties of recrystallized and stress-relieved Zircaloy-4 cladding tubes under biaxial stress conditions

Mihara, Takeshi  ; Udagawa, Yutaka  ; Amaya, Masaki  

In order to elucidate the failure behavior of light water reactor fuel cladding tubes caused by the pellet-cladding mechanical interaction loading under pellet-cladding mechanical interaction conditions, the anisotropic deformation characteristics of Zircaloy4 cladding tubes were investigated. Mechanical tests were performed on recrystallized and stress-relieved Zircaloy-4 cladding tubes at nine stress ratios (=axial stress/ circumferential stress). Both RX and SR materials showed anisotropy in their contours of plastic works. The minimums of the equivalent plastic strains at fracture were located at stress ratios of = 1 and 0.75 for RX and SR materials, respectively.