Corrosion Product Characterization of a Nickel-Sodium Sulfate-Air System after Exposure to Temperatures Near 1000 C^⋆

Gas turbine engines are susceptible to high temperature corrosion which is enhanced by marine atmospheres. This high temperature corrosion is also known as sulfidation because it is believed that the formation of metal sulfides from sulfur containing substances is essential. An understanding of the corrosion mechanisms involved is necessary in seeking methods of eliminating the problem, and the initial step in formulating mechanisms is to identify the chemical reactions involved. Corrosion product characterization is essential for this identification. Characterization of the corrosion products from the nickel-sodium sulfate-air system at temperatures near 1000 C (1832 F) suggests that the sodium sulfate acts as a flux rather than as a chemical reactant. Some of the techniques used to characterize the corrosion products are discussed.