Deposit-Induced Corrosion of a Nickel-based Superalloy

Calcium-containing compounds, originating from sand, marine salts, atmospheric pollutants, and/or fuel impurities can deposit on high temperature gas turbine components. These deposits can destroy protective oxide scales on the surface of the alloy and deplete critical alloying elements in the alloy matrix. This phenomenon can consequently lead to reduced performance and longevity and could end in component failure with serious consequences. The objective of this project was to study high temperature corrosion induced by calcium-based deposits on a second generation Ni-based superalloy. Samples were also subjected to a thermal profile that endeavored to capture service performance more closely as well as isothermal conditions. The talk will report on the effect of these test conditions based on post-test coupon characterization.