Effects of Aging Time on Microstructure and Oxidation Behavior of Inconel 690 Alloy

Abstract

The microstructure and oxidation behavior of Inconel 690 alloy were investigated after aging at 850 °C for different times in air. Also, the relationship between structural stability and oxidation behavior was analyzed. Cr23C6 precipitated at grain boundaries after aging, and the morphology and size of Cr23C6 changed significantly with aging time. Besides, the hardness and oxidation behavior changed with aging time. The oxidation shedding phenomenon occurred after aging at 504 h. And, there was a porous zone beneath the oxide scale when the aging time reached 720 h. Meanwhile, the structural stability was closely related to the oxidation behavior.

Keywords: microstructure, oxidation behavior, aging time, structural stability