Special Aspects of Diffusional Transfer of the Alloying Admixture during Ion Nitriding of the Thermal-Sprayed Coatings

Abstract

The effect of ion-beam nitriding of 09X19H9T austenitic high velocity oxygen fuel coating on phase composition and structure of nitrided layer has been investigated. The distribution of nitrogen atoms in near-surface layer has been studied. It is established that deposited particles with relatively low depth of oxide streaks have higher concentration of alloying element and microhardness. The model connecting inhomogeneous distribution of alloying element in deposited particles with diffusion impermeability of oxide streaks located on the boundaries of the deposited particles has been suggested.

Keywords

• thermal coating
• ion-beam nitriding
• oxide streaks
• concentration discontinuity