Laser Raman Microprobe: A New Technique for the Identification of Corrosion Scale Constituents

摘要

The effectiveness of a laser Raman microprobe, with a two micron spot size and 1 to 2 micron probe depth, to provide microcompositional information about corrosion scales has been assessed. The examination was made of 20%Cr/25%Ni/Nb and 20%Ni/Nb + 0.13%Ce stainless steels oxidized in carbon dioxide based gases. For the first time it has proved possible to establish the unidirectional variation in the constituent phases of a thin (approx. less than 1 micron) oxide scale and also to identify precisely the nature of the oxide layers comprising thicker (8 approx. less than 8 micron) scales.