Grain Boundary Character Distribution in Ni-Cr-W Superalloy

Grain boundary character distribution in cold-rolled Ni-Cr-W superalloys annealed for different time was investigated. Scanning electron microscope (SEM), electron backscatter diffraction (EBSD) and orientation imaging microscopy (OIM) analyses were carried out. The results show that under the cold reduction of 70%, the samples' recrystallization time is relatively short, and the ratio of special grain boundary increases firstly and then decreases with prolonging the annealing time; under the cold reduction of 10%, the recrystallization driving force is small, the recrystallization time is long, and the ratio of special grain boundary reaches the maximum after long-time annealing. In addition, boundaries have Sigma 3(n) misorientations inside the grains-cluster, while misorientations are random for those outside.