Rare earth modified corrosion resistant superalloy with enhanced oxidation resistance and coating compatibility

Abstract

The invention concerns a Ni based alloy suitable for single 5 crystalline, directionally solidified or polycrystalline components to be used at high temperatures. The alloy is a′/ alloy and consists of different alloying elements within defined ranges. Among other defined ranges of elements, the alloy contains Pd in a significant amount sufficient to provide the alloy with an improved resistance against hydrogen embrittlement. The invention also concerns a component designed for use as a component in a high temperature environment. Furthermore, the invention concerns a gas turbine arrangement. Moreover, the invention concerns the use of Pd for providing an alloy with improved resistance against hydrogen embrittlement. The inclusion of two or more rare earth elements in the alloy provides enhanced bondcoat compatibility.

1 . A nickel based superalloy consisting essentially of, in weight percent: 
 13.50 to 14.50 Cr;    8.50 to 10.50 Co;    3.50 to 4.50 Mo;    3.50 to 4.50 W;    0.05 to 2.00 Ta;    2.50 to 3.50 Al;    4.50 to 5.50 Ti;    0.05 to 0.75 Hf;    0.05 to 0.25 Si;    0.05 to 5.0 Pd;    0.01 to 0.03 B;    0.005 to 0.15 Zr;    0.05 to 0.2 C;    0 to 8.0 Re;    0 to 8.0 Ru;    0.001 to 0.25 of a mixture of two or more rare earth elements selected from the group of La, Y, Ce, Nb, Sm, Gd, Pr, and Dy;    less than 0.02 S; and    balance formed from Ni.    
     
     
         2 . A nickel based superalloy of  claim 1 , wherein, in weight percents: 
 13.70 to 14.30 Cr;    9.00 to 10.00 Co;    3.70 to 4.30 Mo;    3.70 to 4.30 W;    0.05 to 0.15 Ta;    2.80 to 3.20 Al;    4.80 to 5.20 Ti;    0.05 to 0.5 Hf;    0.05 to 0.2 Si;    0.05 to 2.0 Pd;    0.01 to 0.02 B;    0.005 to 0.10 Zr;    0.15 to 0.19 C;    1.5 to 2.5 Re;    1.5 to 2.5 Ru;    0.001 to 0.1 of a mixture of two or more rare earth elements selected from the group of La, Y, Ce, Nb, Sm, Gd, Pr, and Dy;    less than 0.02 S; and    the balance formed from Ni.    
     
     
         3 . A nickel based superalloy of  claim 1 , wherein, in weight percents: 
 14.0 Cr;    9.5 Co;    4.0 Mo;    4.0 W;    0.10 Ta;    3.00 Al;    5.00 Ti;    0.10 Hf;    0.10 Si;    0.015 B;    0.05 Zr;    0.17 C;    2.0 Re;    2.0 Ru;    1.0 Pd;    0.02 of a mixture of two or more rare earth elements selected from the group of La, Y, Ce, Nb, Sm, Gd, Pr, and Dy;    less than 2 ppm S; and    the balance formed from Ni.