Effects of Heat Treatment Condition on the Microstructure Evolution of Inconel 690

摘要

The effect of heat treatment on the morphologies of precipitates and grain boundaries of Inconel 690 alloy was studied. When the specimens were slowly cooled from the solutionizing temperature, typical discontinuous coarsening of Cr-rich carbides in grain boundaries was observed. As the cooling rate decreased, Cr-rich carbides grew and wider Cr depletion zone was created between the carbide precipitates, which resulted in wavy grain boundaries. The driving force of the wavy grain boundary was explained by the coherent strain energy.