M23C6 precipitates induced inhomogeneous distribution of silicon in the oxide formed on a high-silicon ferritic/martensitic steel

The effect of Cr-enriched M23C6 carbides distributed at lath boundaries on the oxidation behavior of a high-silicon 12% Cr ferritic/martensitic (HSiF/M) steel has been investigated. The M23C6 carbides were oxidized during the exposure of HSiF/M in air at 823 K. The oxidation of M23C6 carbides promotes the external oxidation of Si at lath boundaries due to the third-element effect, which induces inhomogeneous distribution of elements at the microscale in the oxidation products.