The influence of annealing time on Σ3 boundary and Σ9 boundary evolutions in Hastelloy C-276

Abstract:

Hastelloy C-276 was subjected to low strain deformation and annealed at 1100°C for different times. The Σ3 and Σ9 boundary percentages and grain boundary plane distributions were characterized by electron back-scatter diffraction (EBSD) and the five-parameter analysis method. The results shown that the Σ3 boundary was evolving towards a more exact coincident-site lattice (CSL) misorientation and the Σ3 boundary plane was more close to low surface energy plane {111} with extended annealing time. This is consistent with fine tuning mechanism. While the population of incoherent Σ3 boundary was increasing, the proportion of Σ9 boundary with larger deviations would be increasing. And the distributions of grain boundary density planes forΣ9 boundary were more intensive on the whole [110] zone.