Microstructure Evolution of IC10 Superalloy at Different Service Temperature

The samples used in the present work were taken from the IC10 superalloy blades discarded due to size deviation or other factors. The effects of service temperature and time on microstructure and microhardness of IC10 superalloy were studied. The results show that the volume fraction of the secondary γ′ decreased gradually with the increase of heat exposure temperature and time. At 1 120 ℃, the secondary γ′ phase was obviously spheroidized, and its volume fraction decreased significantly. At 1 200 ℃, the volume fraction decreased to 12.96% after short-term heat exposure (40 h), which indicates that service temperature-time has a significant effect on IC10 microstructure. After thermal exposure, the micro-hardness of IC10 superalloy ranged from HV 354.57 to HV 407.28. At 1 050 ℃, due to strength weakening of the matrix, the hardness of the sample was lower than the standard heat treatment state. Then the secondary γ′ phase began to re-dissolve. The secondary γ' phase’s redissolution basically finished after 1 200 ℃, so that the microstructure was more uniform, composed of fine third-class γ′ phase, and the hardness increased.