The dissolution behavior and kinetics of the (γ + γ′) eutectic microstructure in \(\backepsilon\kappa\) 151 alloy were systematically studied. A Johnson–Mehl–Avrami–Kolmogorov model was established to predict the variation in the (γ + γ′) eutectic volume fraction during homogenization. The results show that the as-cast microstructure exhibits two distinct (γ + γ′) eutectic morphologies: sunflower-like and blocky. Homogenization treatments were conducted at 1080°C, 1110°C, 1140°C, 1150°C, and 1160°C for different durations to observe the dissolution process. The blocky (γ + γ′) eutectic dissolved much faster than the sunflower-like one. Complete dissolution of the blocky (γ + γ′) eutectic occurred at 1140°C/10 h, while the sunflower-like type required 1160°C/45 h. The dissolution process is mainly controlled by the diffusion of Ti. The dissolution of the sunflower-like eutectic is highly temperature-dependent. At 1150–1160°C, influenced by the elastic strain energy between the γ and eutectic γ′ phases, the eutectic γ′ phase underwent splitting, causing the sunflower-like eutectic to fragment into smaller blocks, which subsequently dissolved. The complete elimination of the (γ + γ′) eutectic microstructure significantly improves the mechanical properties of the alloy, providing a theoretical basis for optimizing the hot-working process of \(\backepsilon\kappa\) 151 alloy.
