Carbon induced metal dusting of iron–nickel–chromium alloy surfaces: a scanning auger microscopy study

In this work, we present an investigation on metal dusting of iron–nickel–chromium (Fe–Ni–Cr) alloy surfaces using scanning auger microscopy. It is shown that the formation of surface Cr-oxide and the surface finish condition can strongly influence and interrupt this catastrophic phenomenon. The accumulation of C within the metal matrix was not always prevented by the Cr-oxide layer. The formation of Cr-oxide was accompanied by a depleted Cr layer (next to the oxide layer) with a depth of several hundreds of nanometers. The depleted Cr layer was significantly broader if the C diffusion within the metal matrix was prevented, while no preferential enrichment of Ni or Fe close to the alloy surface was observed