Effect of melt superheating treatment on the cast structure of K465 nickel-based superalloy

The cast structure of a K465 nickel-based superalloy with different temperatures of melt superheating treatment was studied. It is shown that melt superheating treatment plays a significant role in the grain size and carbide morphology. With increasing melt superheating temperature (below 2023 K), the grain size increases obviously and the carbide morphology is changed from a blocky to a script-like shape. However, when the melt superheating temperature is between 2023 K and 2123 K, the grain size decreases gradually, and the morphology of the MC carbide changes back to the blocky appearance. The content of W is also influenced by melt superheating treatment.