Effect of cooling rate on solidification behavior and micro-segregation of high-alloyed wrought superalloy GH4975

• Increasing cooling rate refines dendritic structure and reduces secondary dendrite arm spacing, following λ2=216.78·R^-0.42. • Higher cooling rates enlarge the solidification range by raising liquidus and lowering solidus temperatures, affecting micro-segregation. • Cooling rate significantly influences the size and distribution of MC carbides and eutectic (γ+γ′), with higher rates reducing their sizes but increasing eutectic area fraction. • A moderate cooling rate of 30 °C·min-1 is recommended for optimal solidification of GH4975 alloy to balance microstructural refinement and segregation control.