Microstructure Stability and High Temperature Properties of a New Nickel-base Superalloy after Long-term Aging

The microstructure stability and high temperature properties of a new Ni base superalloy after long-term aging at 850 ℃ for 4 000h were investigated by SEM.The results show that the major precipitated phase of the new alloy were γ′ phase ,MC carbides and a little of M23C6 carbides after aging for 4 000 h.The η phase and σ phase were not detected in all samples.It can be concluded that the microstructure of the alloy is stable and the creep rupture strength of the new alloy had been improved greatly.