Thermal barrier coating for industrial gas turbine blade, and industrial gas turbine using the same

Abstract

Disclosed is a turbine blade for an industrial gas turbine including a blade substrate; a multilayer alloy coating containing a diffusion barrier layer; a bond coat; and a top coat. The blade substrate being formed of a single crystal alloy which consists essentially of 0.06 to 0.08% of C, 0.016 to 0.035% of B, 0.2 to 0.3% of Hf, 6.9 to 7.3% of Cr, 0.7 to 1.0% of Mo, 7.0 to 9.0% of W, 1.2 to 1.6% of Re, 8.5 to 9.5% of Ta, 0.6 to 1.0% of Nb, 4.9 to 5.2% of Al, 0.8 to 1.2% of Co, and the balance being Ni and incidental impurities by weight. The multilayer alloy coating, the bond coat and the top coat being directly and sequentially laminated on a surface of the blade substrate, in which the diffusion barrier layer is a multilayer and a discontinuous layer.

What is claimed is: 
     
         1 . A turbine blade for an industrial gas turbine comprising:
 a blade substrate;   a multilayer alloy coating containing a diffusion barrier layer;   a bond coat; and   a top coat,   the blade substrate being formed of a single crystal alloy which consists essentially of 0.06 to 0.08% of C, 0.016 to 0.035% of B, 0.2 to 0.3% of Hf, 6.9 to 7.3% of Cr, 0.7 to 1.0% of Mo, 7.0 to 9.0% of W, 1.2 to 1.6% of Re, 8.5 to 9.5% of Ta, 0.6 to 1.0% of Nb, 4.9 to 5.2% of Al, 0.8 to 1.2% of Co, and the balance being Ni and incidental impurities by weight,   the multilayer alloy coating, the bond coat and the top coat being directly and sequentially laminated on a surface of the blade substrate,   wherein the diffusion barrier layer is a multilayer and a discontinuous layer.   
     
     
         2 . The turbine blade according to  claim 1 ,
 wherein the diffusion barrier layer is an alloy which contains Re, Cr, and Ni.   
     
     
         3 . An industrial gas turbine including the turbine blade of  claim 1 .