High-strength and high-ductility ni-base superalloys, parts using them, and method of producing the same

摘要

This invention provides an Ni-base superalloy capable of providing the castings with high high-temperature strength and excellent ductility no matter whether it is used for the directionally solidified castings or conventional castings, and suited for casting of the centrifugal wheels of industrial gas turbines, turbo chargers or microturbines. This Ni-base superalloy contains, in percent by weight, 0.06 to 0.3% of C, 0.01 to 0.05% of B, 0.5 to 3.0% of Hf, 10.2 to 25% of Co, 1 to 12% of Ta, 1.5 to 16% of Cr, 2 to 15% of W, 3.5 to 6.5% of Al, 0.5 to 9% of Re, and 0.2 to 2% of Nb.