A Microstructural Investigation of Austenitic Heat Resistant Alloy after 500 h of Steam Oxidation

Alloy 709 was oxidized at 700 degrees C for 500 h in a steam environment. A microstructural analysis of the oxide scale is reported. Modern techniques of advanced electron microscopy were used to characterize the morphology of the oxide scale and recognize its single components. The material developed a complex, multilayered oxide scale. The outermost layer consisting of Fe2O3. Fe2NiO4 tI28 spinel was detected underneath. An internal oxidation zone is present in the innermost layer. High quality SEM-EDS maps give insight into a larger area of the oxide scale at a relatively low magnification.

Automated summary

Alloy 709 was oxidized at 700 degrees C for 500 hours in a steam environment, forming a complex, multilayered oxide scale with an outer layer of Fe2O3 and the detection of Fe2NiO4 tI28 spinel underneath. Advanced electron microscopy techniques were used to characterize the morphology of the oxide scale, revealing an internal oxidation zone in the innermost layer. High-quality SEM-EDS maps provided insight into a larger area of the oxide scale at lower magnifications.