Anomalous cyclic oxidation behaviour of an Fe-Mn-Si-Cr-Ni alloy - A finite element analysis

High temperature cyclic oxidation behavior of a low manganese Fe12Mn9Cr5Si4Ni-NbC shape memory stainless steels

“…Regarding the mass variation (Figure 1), the behavior observed at 900 °C was reported previously for an Fe-17Mn-5Si-10Cr-4Ni-VC and considered anomalous [13,15] as usually, after the spallation start, the alloy presents continuous mass loss under cyclic oxidation. At 800 °C, it is important noticing that no spallation was observed during oxidation what is a detrimental 9 behavior of some austenitic stainless steels at high temperature [14].…”

“…These voids allow oxygen transport with relatively high partial pressure. The second aspect is concerned to cyclic oxidation, which can promote oxide [13,15,16], and supported by the cracks observed (Figure 6 and 7) and the anomalous behavior of mass variation observed at 900 °C (Figure 1). Thus, these defects can break the continuous spinel layer and expose the Mn-depleted ferrite layer to a high oxygen partial pressure, promoting oxygen inward and forming Mn-rich oxides inside the substrate.…”

“…After some oxide spallation and mass loss, the material returned to gain mass. This uncommon behavior was first related to the roughness increase at the metal/oxide interface, generated by ferrite layer plastic deformation [13,15]. After that, a comparison between isothermal and cyclic oxidation was performed at 950 °C for the Fe-13.58Mn-5.58Si-9.42Cr-3.86Ni-0.18Ce alloy [16], demonstrating that the roughness increasing at metal/oxide interface is derived from a chemical and mechanical combined effect, as the isothermally oxidized samples also presented rough interfaces in a low degree when compared to cyclic oxidized samples.…”