Methods of applying chromium diffusion coatings onto selective regions of a component

摘要

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.

主权项

1. A method for producing a chromium diffusion coating onto selected regions of a substrate, comprising the steps of:
providing a chromium-containing slurry; applying the chromium-containing slurry onto localized surfaces of the substrate; curing the slurry; heating the slurry in a protective atmosphere to a predetermined temperature for a predetermined duration; generating chromium-containing vapors; diffusing the chromium into said localized surfaces to form the coating, said coating having a microstructure characterized by a substantial reduction in nitride and oxide inclusions and reduced levels of α-Cr phase in comparison to conventional chromizing processes.