| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
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| Symposium
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Advances in High-Temperature Oxidation and Degradation of Materials for Harsh Environments: A SMD and FMD Symposium Honoring Brian Gleeson
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| Presentation Title |
H-10: Effect of Al Content of β-NiAl on Initial Sulfate Deposit-Induced Corrosion |
| Author(s) |
Taisei Iwasaki, Shigenari Hayashi, Suzue Yoneda, Kotaro Mizushino, Yasuo Matsunaga, Atsushi Tsuru |
| On-Site Speaker (Planned) |
Taisei Iwasaki |
| Abstract Scope |
Ni-based superalloys used in aircraft turbine components are often coated with a β-NiAl to improve oxidation resistance. However, corrosion occurs when alkali sulfates are deposited in the low-temperature region of the coating. In this study, corrosion behavior of β-NiAl alloys with different Al content was investigated with a Na2SO4 deposit at 750°C in N2-20%O2-0.04%SO2-10%H2O (PSO3 = 1.5×10-4). Cross-sectional observations of samples after 15min of corrosion revealed that corrosion products were deeply penetrated into the alloy substrate in the localized areas of low Al alloys. Those regions were confirmed to transition to nodules. The Al depleted γ' phase layer was formed under the Al2O3 layer in the low Al alloy during the early stage of corrosion, which might promote the sulfidation of Ni, leading to deep penetration of corrosion products into the substrate. |