Effect of melt treatment on carbides formation in a cast nickel-base superalloy M963

The microstructures of a cast nickel-base superalloy M963 with both no melt treatment and melt treatment at 1923 K for 5 min were investigated in detail. The results show that the melt treatment has a significant role on the carbides formation in the alloy. The MC carbide tends to have blocky morphology in the alloy with no melt treatment, while it has a Chinese script-like morphology in the alloy with melt treatment at 1923 K for 5 min. During the solution heat treatment at 1248 K for 4 h followed by air-cooling, much more acicular M6C carbide precipitates in the alloy with no melt treatment.