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

Abstract

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.

Creep and oxidation kinetics at 1100°C of nickel-base alloys reinforced by hafnium carbides

“…In the later cases powder metallurgy (PM) or conventional casting must be considered. When high mechanical resistance is required at temperatures higher than 1000°C, the small grains of alloys issued from PM process [10][11][12][13][14][15] are not suitable, unlike the coarser grains resulting from casting [16][17][18][19][20][21].…”

Effect of Melt Superheating Treatment on the Microstructures and Purity of a Directionally Solidified Superalloy

“…Recent studies have shown that MST (melt superheating treatment) can not only optimize the microstructure of the alloy, but also improve the purity of the alloy [10][11][12]. Pei and Tian [10] studied the variation of nitrogen content in a nickel-based alloy after a melt superheat treatment at different temperatures. Under the same casting temperature and mold shell temperature, increasing the MST temperature can promote the denitrification of the alloy.…”