Texture development and mechanical behavior of Zircaloy-4 alloy plates fabricated by cold rolling and annealing

Abstract

Abstract The effect of cold rolling and annealing on texture development and mechanical behavior of Zircaloy-4 alloy plates was systematically investigated in the present work. The as-received plates were subjected to cold rolling with thickness reductions of 33% and 66%. Electron back-scatter diffraction and tensile tests were performed to reveal the texture and mechanical properties, respectively. Results showed that a bimodal texture was featured in the as-received plate and the texture was a fiber that spread from 10 1 ‾ 0 > to 11 2 ‾ 0 >. After cold rolling and annealing, a fiber with a continuous distribution from 10 1 ‾ 0 > to 11 2 ‾ 0 > and a fiber with a maximum at the 11 2 ‾ 0 > position were present in the plates with thickness reductions of 33% and 66%. Besides, the existence of { 0001 } basal fiber was noticed, indicating more basal poles oriented toward the normal direction. Tensile tests showed that the recrystallized plate with 66% thickness reduction was more ductile and less strong than that with 33% reduction. Meanwhile, tensile properties were sensitive to strain rate, loading direction and thickness reduction. Moreover, the relationship between texture development and yield strength was discussed based on Schmid theory. Calculated results indicated that prismatic slip was the predominant deformation mode and its Schmid factor values under different loading directions contributed to the anisotropy of yield strength. Due to the texture development during cold rolling and annealing, the averaged SF values for prismatic slip changed with the increased thickness reduction, resulting in the variation of yield strength.