Microstructure evolution of alloy 709 during static-aging and creep-fatigue testing

Alloy 709 (20Cr–25Ni-1.5Mo–Nb steel), a candidate structural alloy for Gen IV nuclear reactors, is expected to undergo microstructural evolution during long-term service at elevated temperatures, which in turn affects the mechanical behavior through changing contributions from precipitate and solute strengthening. For safe reactor design, it is important to understand how microstructural evolution and mechanical behavior differ between long-term...