The morphology evolution of lamellar δ phase in Inconel 718 during Delta Processing was characterized by scanning electron microscopy, electron backscatter diffraction, and transmission electron microscopy. A spheroidization mechanism is proposed for transformation of the lamellar δ phase. The results showed that lamellar δ phase hindered the movement of dislocations, which led to a dislocation aggregation zone around the fracture location of the δ phase. Strain in the region thus increased, which promoted the occurrence of dynamic recrystallization and fracture of the lamellar δ phase. A diffusion channel for Nb atoms was simultaneously provided by the high-density dislocations, which led to dissolution and reduction in the amount of δ phase. Under the combined action of deformation, fracture, and dissolution, the lamellar δ phase gradually transformed into granular short rods and spheroids.

通过扫描电子显微镜，电子反向散射衍射和透射电子显微镜表征了Inconel 718 Delta处理过程中层状δ相的形貌演变。提出了一种球化机理，用于层状δ相的转变。结果表明，层状δ相阻碍了位错的运动，从而导致了δ相断裂位置周围的位错聚集区。因此该区域中的应变增加，从而促进了动态再结晶的发生和层状δ相的断裂。高密度位错同时提供了Nb原子的扩散通道，从而导致了δ相的溶解和减少。在变形，断裂和溶解的共同作用下，