Use of Laser Raman Spectroscopy to Study Hot Corrosion of Ni-Cr Alloys.

摘要

Raman scattering has been combined with more conventional surface-analytical techniques to identify corrosion species on Ni-Cr alloys after exposure to molten Na sub 2 SO sub 4 at 1000 exp 0 C in air for 60 minutes. At low Cr contents, NiO is the primary oxidation product, and, at intermediate Cr contents, NiCr sub 2 O sub 4 predominates. Higher Cr contents (15 wt % and greater) produce a coherent Cr sub 2 O sub 3 scale. The sulfidation is severe for Ni-2Cr but mild for the other alloys. The degree of sulfidation for Ni-15Cr and greater is independent of alloy composition. Scanning electron microscopy and energy dispersive x-ray enalysis were used to verify the Raman results. (ERA citation 08:033971)