Microstructure evolution and recrystallization behavior of cold-rolled Zr-1Sn-0.3Nb-0.3Fe-0.1Cr alloy during annealing
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Materials, Ministry of Education, Central South University, Changsha 410083, China;
3. Science and Technology on Reactor Fuel and Materials Laboratory, Nuclear Power Institute of China, Chengdu 610213, China)
Abstract: The effects of cold-rolling reduction, annealing temperature, and time on recrystallization behavior and kinetics of cold-rolled Zr-1Sn-0.3Nb-0.3Fe-0.1Cr alloy were investigated using the Vickers hardness test, scanning electronic microscopy (SEM), transmission electron microscopy (TEM) and electron backscatter diffractometry (EBSD). The results show that the rate of the recrystallization increased with increasing annealing temperature and rolling reduction. Recrystallized grains nucleated preferentially at sites with high density dislocation and deformation stored energy and then grew into integral grains. Recrystallization texture changed from //RD to //RD. The grain orientation changed from random orientation to the orientation with the maximum misorientation around 30°. Recrystallization kinetics and maps were constructed based on the Johnson–Mehl– Avrami–Kolmogorov (JMAK) equation to derive parameters sensitive to the microstructure. The activation energies for recrystallization of 30%, 50% and 70% cold-rolling reductions were determined to be 240, 249 and 180 kJ/mol, respectively.
Key words: zirconium alloy; recrystallization; microstructure; texture evolution; kinetics