Modifying Microstructures and Enhancing Mechanical Properties of Spinning Hastelloy C276 Superalloy Components by Annealing Treatment

The presence of complex microstructures, including deformed grains and high‐density substructures formed during spinning, profoundly impacts the mechanical properties of spinning Hastelloy C‐276 components. This work aims to investigate the microstructural evolution and mechanical property changes of spun Hastelloy C‐276 superalloy components during annealing. Experimental results confirm that subgrain aggregation/coalescence and reconfiguration of dislocation networks/cells through cross‐slip/annihilation occur with a rise in annealing temperature or prolonged time, which also promotes the nucleation/coarsening of static recrystallization (SR) grains. The precipitation of tiny granular μ‐phases is accelerated at higher annealing temperatures or longer durations, but the microstructure undergoes a notable transition for temperatures arriving at 1050°C, where the tiny μ‐phases diminish and give way to coarsened, short‐rod morphologies. In addition, the microstructure consisting of uniformly distributed fine SR grains and dispersed μ‐phases obtained under elevated annealing temperatures or prolonged holding times leads to a simultaneous enhancement in mechanical strength. Meanwhile, it promotes dimple coalescence and the formation of serpentine slip bands and toughness dimples.