Stress Variation of Zircaloy-4 and Johnson Cook Model for rolled sheets.

Abstract Zircaloy-4, a promising structural alloy in the core of nuclear reactors, need to sustain thermal stresses when it is in the form of cladding tubes, spacer grids in nuclear fuel assembly. Yield stress variations with respect to temperature and strain rates in three orientations of pilgered and rolled sheets are presented in this paper. The stresses have showed very good correlation with an equation of power 3 in three orientations (0 o , 45 o and 90 o to rolling direction). Along with the tensile test results a constitutive Johnson Cook model is developed to observe the effects of strain rates and temperature on the stresses.