HAYNES NS-163 Alloy: A Novel Nitride Dispersion-Strengthened CO-Base Alloy
HAYNES® NS-163® alloy was developed by Haynes International Inc., Kokomo, IN, for high-temperature structural applications by pursuing a dual manufacturing approach: the fabrication of components in the readily weldable and formable mill-annealed condition, and their subsequent strengthening by means of a gas nitriding process. The latter process results in dispersion-strengthening by virtue of formation of internal nitrides. Since this process is diffusion-controlled, component section thicknesses are limited to approximately 2.0 mm (0.080 in.). Microstructures and mechanical properties of nitrided sheet samples are presented. Oxidation resistance and the need for coatings at temperatures exceeding 980 °C (1800 °F) are addressed as well.