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

摘要

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. Thus, the thermal barrier coating structure including a diffusion barrier layer can be provided for the single-crystal turbine blade for the industrial gas turbine formed of a single crystal alloy. The thermal barrier coating structure can suppress growth of a secondary reaction zone caused by element diffusion into the substrate, and can provide durability against thermal fatigue due to thermal cycles and durability against mechanical fatigue.