Effect of Cooling Rate on the Solidification Behavior of GH4151

The new nickel-based superalloy GH4151, with a service temperature capability of up to 800°C, is a most promising materials. Due to the high alloying nature of GH4151, severe microsegregation and precipitation occur during the solidification process, affecting alloy uniformity and even leading to hot cracking during solidification, which is unfavorable for alloy casting. This study investigates the phase precipitation patterns during GH4151 solidification, and the influence of cooling rate on the solidification behavior. It elucidates the sequence of phase precipitation during solidification, alloy constants, and the impact of cooling rate on the microstructure and element segregation during solidification. It was observed that, with increasing cooling rate, the degree of segregation of some alloying elements increases within the range of 3–18°C/min, while it decreases outside this range. Properly increasing the cooling rate results in better as-cast microstructures. This work lays the foundation for future research into the hot cracking mechanisms of GH4151.