A nickel-chromium-iron alloy (Inconel 600) was exposed to water at elevated temperatures and pressures (approaching conditions of the critical point of water). This alloy is used in boiler systems and the mechanisms of corrosion and failure are of interest. The water temperatures and pressures were selected to simulate conditions to which this alloy might be exposed during operation. Two coupons were exposed under slightly difference conditions and differences in degree of corrosion were observed. While the alloy composition is well known, the composition of the corrosion layer depends strongly on exposure conditions. Auger electron spectrometry was applied to help investigate the composition of the corrosion layer. The discontinuous nature of the oxidation layer and the proximity to the unoxidized substrate make this a challenging analysis. Auger analysis is complimented with energy dispersive spectrometry, and focused ion beam techniques to solve this complicated analysis problem.