High strength Ni-base superalloy for directionally solidified castings

摘要

In order to provide a high strength Ni-base superalloy for directionally solidified castings, which is prevented from solidification cracking at the casting, having a sufficient grain boundary strength for ensuring reliability during its operation and a superior high temperature concurrently, a high strength Ni-base superalloy for directionally solidified castings having a superior grain boundary strength, which contains C: 0.05 % to less than 0.1 %, B: 0.015 % to 0.04 %, Hf: 0.01 SIMILAR less than 0.5 %, Zr: less than 0.01 %, Cr: 1.5 % SIMILAR 16 %, Mo: utmost 6 %, W: 2 SIMILAR 12 %, Re: 0.1 SIMILAR 9 %, Ta: 2 SIMILAR 12 %, Nb: utmost 4 %, Al: 4.5 SIMILAR 6.5 %, Ti: less than 0.5 %, Co: less than 9 %, and Ni: at least 60 % in weight, is disclosed. <IMAGE>