Effects of different C contents on the microstructure, tensile properties and stress-rupture properties of IN792 alloy

IN792 alloy containing different C contents (0.016–0.21%) was refined in vacuum induction melting furnace. The morphology, size and area fractions of γ′ and carbides were investigated with change of C contents in alloys from 0.016% to 0.21%. No variations were observed in morphology and size of γ′ phase, and very small variation of area fraction of γ′ was observed in alloys with different C contents. The area fractions of carbides varied from 1.10% to 2.72% among alloys with different C contents. When C contents were in range of 0.05–0.14%, the small size carbide particles of MC and M23C6 were prone to appear. When C contents were in range of 0.13–0.21%, the large size of carbide particles formed in grain boundary with film and big block. With increasing C content, the stress-rupture lives of specimens increased in the range of 0.016–0.086% and decreased in the range of 0.086–0.14%, but they did not change when the C contents was above 0.14%.