  The effects of surface preparations on oxidation kinetics and oxide scale
morphology for the commercially available Ni-based superalloy IN 713C have been
investigated. The ground and polished samples were exposed in air at 800-1100C.
The ground specimens were found to demonstrate lower oxidation kinetics
compared to those after polishing. The grinding also affected the oxide scale
morphology, resulting in a protective alumina scale, while the polished samples
developed Ni-/Cr-rich mixed oxides on the surface. Better oxidation resistance
of the ground surfaces is related to a higher concentration of defects in the
nearsurface region introduced by cold working. These defects facilitate the
outward transport of the scaleforming element Al and thus are beneficial for
protective oxidation. The oxidation mechanism at lower temperatures was
introduced. The model based on the generalized Darken method and multiphase
approximation was proposed.
