| 摘要 |
PROBLEM TO BE SOLVED: To improve the yield of an allowable heat-treated single crystal casting by forming an Ni superalloy single crystal casting, introducing carbon into the casting and subjecting the casting to heat treatment in the presence of gas seed effective for forming carbide reducing the recrystallization of grains in the casting in the process of the heat treatment. SOLUTION: As the casting concretely capable of heat treating, the one having the following compsn. can be given: it is composed of, by weight, about 6 to 6.8% Cr, about 8 to 10% Co, about 0.5 to 0.7% Mo, about 6.2 to 6.6% W, about 6.3 to 7.0% Ta, about 5.4 to 5.8% Al, about 0.6 to 1.2% Ti, about 0.10 to 0.3% Hf, about <200 ppm B, about <50 ppm Mg and about <200 ppm C, and the balance essential Ni. In this way, casting so as to form a single crystal structure for the vane and blade (airfoil group) of a gas turbine engine in particular is made possible.
|
