17 – Alloy 263

Alloy 263 is an age-hardenable nickel-cobalt-chromium-molybdenum base alloy with excellent strength in the range 540–870°C, and excellent forming and welding characteristics. This alloy was developed for aircraft engine application, but more recently, it was taken into account for new applications like forged, cast, and pipe components for A-USC power plants. Alloy 263 exhibits excellent intermediate temperature tensile ductility, and it is not normally subject to strain age cracking common for the γ′-strengthened alloys. Its oxidation resistance is comparable to that for the other γ′-strengthened superalloys. The long-term creep properties in the temperature range for A-USC power plants have to be validating with assessment.