Microstructural Degradation and Creep Property Damage of a Second-Generation Single Crystal Superalloy Caused by High Temperature Overheating

Nickel base superalloys are widely used to manufacture turbine blades, and overheating poses a serious threat to the safe service of turbine blades. In this study, a second-generation nickel base single crystal superalloy was taken as the research object, and we carried out the overheating treatment at 1100 °C and 1300 °C, and then tested the creep properties at 1000 °C/300 MPa and 1100 °C/130 MPa. Through systematic analysis of creep properties, γ/γ' phases, and creep voids, the effects of overheating on the microstructures and creep properties of the experimental superalloy were revealed. The results demonstrate that the effect of overheating at 1100 °C on the microstructure of the experimental superalloy can be ignored, and the effect on the creep property is limited. The degree of γ' dissolution is gradually increased and the creep property is reduced with overheating time extending at the overheating temperature of 1300 °C.