A gas turbine component for use in a gas turbine engine includes a substrate a ceramic-based thermal barrier coating (TBC), and a diffusion chromide bond coat between the base material and the TBC. A thermally grown oxide (TGO) layer can be formed on the bond coat prior to application of the TBC. The TBC and the TGO include a common metal oxide. The oxide can be sacrificially in use and soluble in a molten sulfate salt, make the coating system particularly suitable for use in a marine environment.

A method for coating a metallic substrate includes applying an MCrAlY coating. Machining removes the MCrAlY coating from one or more regions of the substrate. A simultaneous aluminizing and chromizing: aluminizes an interior surface region of the substrate lacking the MCrAlY and at least a portion of a region where the MCrAlY remains; and chromizes an exterior surface region of the substrate lacking the MCrAlY and at least a different portion of the region where the first MCrAlY remains.

Unique and improved chromizing processes are disclosed. The processes involve forming localized chromizing coatings onto selected regions of a substrate. The chromium diffusion coatings are locally applied to selected regions of substrates in a controlled manner, in comparison to conventional chromizing processes, and further in a manner that produces less material waste and does not require diffusion-stop-off masking. Prior to or after a localized slurry chromizing process of the present invention, a layer of a platinum-group-metal (PGM) is applied to produce a PGM-modified chromium diffusion coating onto selected regions of a substrate. A second coating can be selectively applied onto other regions of the substrate.

Unique and improved chromizing processes are disclosed. The processes involve forming localized chromizing coatings onto selected regions of a substrate. The chromium diffusion coatings are locally applied to selected regions of substrates in a controlled manner, in comparison to conventional chromizing processes, and further in a manner that produces less material waste and does not require diffusion-stop-off masking. Prior to or after a localized slurry chromizing process of the present invention, a layer of a platinum-group-metal (PGM) is applied to produce a PGM-modified chromium diffusion coating onto selected regions of a substrate. A second coating can be selectively applied onto other regions of the substrate.

Unique and improved chromizing processes are disclosed. The processes involve forming localized chromizing coatings onto selected regions of a substrate. The chromium diffusion coatings are locally applied to selected regions of substrates in a controlled manner, in comparison to conventional chromizing processes, and further in a manner that produces less material waste and does not require masking. A second coating can be selectively applied onto other regions of the substrate.

Unique and improved chromizing processes are disclosed. The processes involve forming localized chromizing coatings onto selected regions of a substrate. The chromium diffusion coatings are locally applied to selected regions of substrates in a controlled manner, in comparison to conventional chromizing processes, and further in a manner that produces less material waste and does not require masking. A second coating can be selectively applied onto other regions of the substrate.