Hot Corrosion Resistance of Nickel‐Chromium‐Aluminum Alloys

The hot corrosion resistance of nickel‐chromium‐aluminum alloys was examined by cyclically oxidizing sodium sulfate‐coated specimens in still air at 900°, 1000°, and 1100°C. The compositions tested were within the ternary region: Ni; Ni‐50 atom percent (a/o) Cr; and Ni‐50 a/o Al. At each temperature the corrosion data were statistically fitted to a third‐order regression equation as a function of chromium and aluminum contents. From these equations corrosion isopleths were prepared. Compositional regions with the best hot corrosion resistance were identified.