|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||High Temperature Corrosion of Structural Materials
||Oxide Scale Formation on Cast Ni-base Superalloys in High pO2-environments: Effect of Alloying Additions and Presence of Water Vapor in the Test Gas
||Dmitry Naumenko, Katja Wollgarten, Timur Galiullin, Wojciech Nowak, Willem Josef Quadakkers
|On-Site Speaker (Planned)
Oxide scale formation on cast, model alloys based on Ni-14Cr-9Co (wt.%) with and without additions of Al (3%) as well as Ti, Ta or Ti and Ta (5% of each element) at 950°C was studied in synthetic air and synthetic air with 20 vol.% water vapor up to 100 hours. Analytical characterization of the oxidized specimens involved GD-OES and SEM/EDX.
The presence of water vapor in the test gas had a clear detrimental effect on the ternary NiCoCr alloy, which rapidly failed by breakaway oxidation (Ni-rich oxide formation). The quaternary NiCoCrAl alloy was less affected by water vapor and formed in many areas a rather protective chromia scale. Formation of faster growing chromia scales on the Ti and Ti+Ta containing NiCoCrAl-alloys was hardly affected by water vapor. Ta-containing, Ti-free alloy formed in both environments mainly an alumina scale resulting in the slowest oxidation kinetics in the studied alloy series.
||Planned: Supplemental Proceedings volume