Phenomena of metal dusting on iron and nickel (and their alloys) were studied by characterizing bothmicrostructure and nanochemistry of the reaction zones using TEM and AEM techniques. While incase of iron a metastable carbide (cementite) is formed nickel directly disintegrates. In thechromium-rich steel HK40 and the chromium-rich Ni-base alloy Inconel 600 some microstructuralchromium dependent features were observed with protective effects against metal dusting.Independent of these differences, in all groups of materials a fundamental common startingmechanism on the atomic scale could be deduced, which first of all comprises the arrangement ofbasal graphite lattice planes perpendicularly oriented to the carbide (or metal) surface acting as activesites in the disintegration process.
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