Coated turbine component and its fabrication

A coated gas turbine component, comprising:

• a gas turbine component comprising a base metal, the gas turbine component being selected from the group consisting of a turbine blade and a turbine vane and including
• a platform,
• a shank extending downwardly from the platform, and
• an airfoil extending upwardly from the platform;
• a first coating contacting the base metal of at least a portion of the shank and interdiffused therewith, the first coating comprising a first chromide layer comprising an average of from about 20 to about 30 weight percent chromium;
• and
• a second coating contacting at least a portion of the airfoil, the second coating comprising
• a second chromide layer contacting the base metal of the airfoil and interdiffused therewith, the second chromide layer comprising an average of from about 20 to about 30 weight percent chromium, and
• a protective layer overlying the second chromide layer and interdiffused therewith, the protective layer comprising a material selected from the group consisting of a diffusion aluminide and a diffusion platinum aluminide.

A method for preparing a coated gas turbine component comprising a base metal, the method including the steps of

• furnishing a gas turbine component comprising a platform, a shank extending downwardly from the platform, and an airfoil extending upwardly from the platform;
• first applying a first coating overlying the base metal of at least a portion of the shank and interdiffused therewith, the first coating comprising a first chromide layer;
• and
• second applying a second coating overlying at least a portion of the airfoil, the second coating comprising
• a protective layer selected from the group consisting of a diffusion coating and an overlay coating.