Ni-based single crystal alloy and casting

摘要

Disclosed is a single crystal alloy consisting essentially of, by weight, 0.06-0.09% carbon, 0.016-0.035% B, 0.2-0.4% Hf, 0-0.02% Zr, 6.5-8.5% Cr, 0.4-1.0% Mo, 5.5-9.5% W, 1.2-3.1% Re, 8-10% Ta, 0.3-1.0% Nb, 0-0.4% Ti, 4.7-5.4% Al, 0.5-5.0% Co, 0.1-5% Fe, and the balance of Ni and unavoidable impurities. The alloy is free from solidification cracks during casting a large-sized blade of gas turbines, has grain boundary strength sufficient for assuring the reliability during operation, and further has excellent oxidation resistance to a high combustion gas temperature while having excellent high-temperature strength comparable to that of a conventional single crystal alloy.