Oxidation of Sanicro 25 (42Fe22Cr25NiWCuNbN) in O2 and O2 + H2O Environments at 600-750°C

Journal article, 2015

The present study investigates the isothermal oxidation behaviour of Sanicro 25 (42Fe22Cr25NiWCuNbN) in dry and wet environments at 600-750 A degrees C. GDOES, SEM, TEM and EDX were used as analytical techniques. The alloy formed a protective oxide when exposed in dry O-2 (600-750 A degrees C). When water vapour was present, the oxide exhibited protective behaviour only at 600 A degrees C with breakaway occurring at 700 and 750 A degrees C. Apparently, the chromium supply from the bulk was not able to counteract the increasing rate of chromium evaporation favoured by water vapour in the latter conditions and thus breakaway oxidation occurs.