aSuperalloys Division, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
bCollege of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
Abstract:
The recrystallization behavior in a range of annealing temperature from 1020 to 1280 °C in a directionally solidified cobalt-base superalloy was studied. Local recrystallization first appeared at 1040 °C. The recrystallized volume increased rapidly as increasing the annealing temperature. Pinning effect of all carbides (M23C6, M7C3 and MC) was observed and large amount of twin formed at low annealing temperature. The size of the recrystallized grains increased significantly at high annealing temperatures accompanied with the sharp decrease of twin. The effect of annealing temperature and the role of carbide and twin on the development of the recrystallization were discussed.