Oxidation behaviour of a developmental nickel-based alloy and the role of minor elements

The oxidation kinetics of a chromia forming development nickel-based superalloy over the temperature range of 700–850 °C under isothermal and 100 h thermal cycles are presented. The kinetics compare favourably with similar alloys and this is attributed to the formation of (Ti,Nb,Ta)(N,C,B) precipitates found throughout the alloy. Between 840 and 850 °C an increase in the oxidation kinetics was observed; attributed to the dissolution of the precipitates, releasing titanium, tantalum and niobium into the alloy matrix. The results are discussed in terms of potential effect of the presence of (N,C,B) phases and stability on the oxidation kinetics.