Towards Understanding the Oxide Evolution in Inconel 740H and Haynes 282 in Ambient Pressure Steam Oxidation

Abstract

Advanced ultra-supercritical (AUSC) power plants with the capacity to produce cleaner and efficient energy require materials compatible for operating at temperature and pressure of 750 °C and 350 bar, respectively. Among various structural materials, Inconel 740H and Haynes 282 are two candidate alloys for the AUSC plant. The present study was designed to investigate the ambient pressure steam oxidation of these alloys at 700 °C by exposing them for 100, 250 and 500 h. Quantitative evaluation of both the alloys indicates a comparable and a significantly low parabolic oxidation growth rate (~ 10–8 mg2 cm−4 h−1). The degradation behaviour, in particular, the oxide growth, is dominated by the Cr2O3-rich outer layer and internal oxidation region rich with oxides of Al and Ti.