| 摘要 |
An alloy for use in the form of a single crystal casting comprises 7-13% Cr, 2-15% Co, 0.2-5% Ti, 4.5-6.7% Al, 7-12% W, 0-1% Nb, 0-1% Mo, 1.5-5% Ta, 0-2% Hf, 0.015-0.05% C, 0-0.01% B, 0-0.05% Zr, balance Ni. Prefd. alloys contain 8-10% Cr, 2-11(3-7)% Co, 1.25-1.75% Ti, 5.25-5.75% Al, 9-11% W, 2.25-5% Ta, 0-1.7% Hf, 0.015-0.05% C, 0-0.01% B, 0-0.01% Zr, balance Ni. The alloy may be soln. heat treated at 1300-1320 deg.C for 1 hr. followed by cooling to room temp. and ageing at 870 deg.C for 16 hrs. Typically, the alloy has a stress life at 730 MPa at 760 deg.C of 435 hrs. cf. 187 hrs. for a similar superalloy. The alloy is used to cast gas turbine rotor blades and other turbine components. Life of components cast from alloy is increased. |
