The Department of Energy and Ohio Coal Development Office jointly sponsored research to evaluate materials for advanced ultrasupercritical (A-USC) coal power plants, testing both monolithic tube materials and weld overlay combinations under real operating conditions. Testing was conducted in the highly corrosive, high-sulfur coal environment of Reliant Energy's Niles Plant Unit 1 boiler in Ohio. After 12 months of exposure, researchers evaluated six monolithic tube materials and twelve weld overlay/tube combinations for their high-temperature strength, creep resistance, and corrosion resistance in both steam-side and fire-side environments. Among the monolithic materials, Inconel 740 demonstrated superior corrosion resistance with the lowest wastage rate, while EN72 emerged as the most effective weld overlay material across various substrates, offering consistent protection against corrosion.