| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing a large-sized ingot of excellent quality which includes reduced segregation and is suitable for the production of a large-sized member by reducing the occurrence of streak-shaped segregation upon the production of a stock using an Ni-based superalloy. <P>SOLUTION: An Ni-based superalloy includes a composition comprising 0.005 to 0.15% C, ≤0.3% Si, 8 to 22% Cr, 5 to 30% Co, 1 to 9% Mo, 5 to 20% W, 0.1 to 2.0% Al, 0.3 to 2.5% Ti, ≤0.015% B and ≤0.01% Mg, and, if required, comprising one or more selected from among ≤0.2% Zr, ≤0.8% Hf and Nb+1/2≤1.5%, and the balance Ni with inevitable impurities. By making the distribution coefficient of W remarkably promoting the occurrence of the segregation streak close to 1, the density difference between a base molten steel and a concentrated molten steel is reduced to reduce the appearance of streak-shaped segregation and thus, a large-sized ingot of excellent quality having reduced segregation and suitable for the production of a large-sized member can be produced. <P>COPYRIGHT: (C)2009,JPO&INPIT |
