High-Temperature Oxidation and Hot Corrosion Behaviors and Mechanism of One Typical Aero-Engine Material 0Cr18Ni9 by One Novel Superhydrophobic and Oleophobic Ultrafine Dry Powder Extinguishing Agent

The macroscopic and microscopic surface morphology, products, kinetics, and reaction mechanism of one typical aero-engine material 0Cr18Ni9 in the cases of high-temperature oxidation and hot corrosion by a novel superhydrophobic and oleophobic ultrafine dry powder extinguishing agent (SHOU DPEA) are studied in a simulated aircraft engine compartment working environment. The results demonstrate that the oxidation and corrosion products both contain FeCr 2 O 4 , Fe 2 O 3 , and Fe 3 O 4 . However, the presence of SHOU DPEA accelerates the corrosion within the alloy. The 0Cr18Ni9 substrate shows a L-shaped segregation phenomenon and a chromium-poor layer. Furthermore, the oxidation and corrosion kinetic curves of 0Cr18Ni9 are both parabolic. In particular, the high-temperature oxidation behavior of 0Cr18Ni9 can be divided into two stages: a rapid oxidation stage (0-96 hours) and an oxidation equilibrium stage (96-192 hours), and the hot corrosion process can be divided into two stages: an initial slow incubation stage from 0 to 48 hours, and an accelerated corrosion stage from 48 to 192 hours. Additionally, the chemical reaction mechanisms for oxidation/corrosion are illustrated. Graphical Abstract