Columnar crystalline Ni-base heat-resistant alloy having high resistance to intergranular corrosion at high temperature, method of producing the alloy, large-size article, and method of producing large-size article from the alloy

摘要

An Ni-base heat resistant alloy, has a composition which contains, by weight, Cr: from 12.0 to 14.3 %, Co: from 8.5 to 11.0 %, Mo; from 1.0 to 3.5 %, W: from 3.5 to 6.2 %, Ta: from 3.0 to 5.5 %, Al: from 3.5 to 4.5 %, Ti; from 2.0 to 3.2 %, C; from 0.04 to 0.12 %, B: from 0.005 to 0.05 %, and the balance substantially Ni and inevitable impurities. A large-size casting, as well as a large-size turbine blade, having a columnar crystalline Ni-base heat-resistant alloy formed from the Ni-base heat-resistant alloy, have sound cast surfaces and a sound internal structure.