Single-step aging treatment for a precipitation-strengthened Ni-based alloy and its influence on high-temperature mechanical behavior

Abstract A simplified aging treatment yielded microstructural features in Ni-based alloy that produced strengthening behavior normally associated with more complex thermal processing. Specifically, a time series of 800 °C heat treatments was used to study the evolution of grain boundary carbides and γ' precipitates and the corresponding hardness, tensile strength, and creep resistance. These analyses and computational thermodynamic calculations revealed that a 4-hour aging treatment produced appropriately sized and uniformly distributed coherent γ' precipitates and the desired Cr-rich carbides like those formed during the conventional two-step heat treatment. Accordingly, the former heat treatment produced targeted typical strength levels for this alloy.