Microstructural stability and tensile properties of a new γ′-hardened Ni-Fe-base superalloy

The microstructure and tensile properties of a new γ′-hardened Ni-Fe-base superalloy HT700T in solutionized state are investigated after thermal exposure at 800 °C for different durations. Within the grain interior, the average size of γ′ precipitates increases from 28.3 to 274.1 nm with increasing aging time from 8 to 10,033 h, but its volume fraction and morphology remain unchanged with time. At grain boundaries, MC carbide and M23C6 carbide...