IN 939 is designed for industrial gas turbines operating on low-grade fuels where hot corrosion resistance at temperatures up to 900°C is the primary material requirement. Its high chromium and cobalt content provide strong sulfidation and oxidation resistance, while gamma prime precipitation delivers adequate creep strength for stationary vane and rotating blade applications. Qualified under PWA 1495, IN 939 is a well-established alloy for long-interval overhaul industrial power generation applications.