| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Advanced Coatings for Wear and Corrosion Protection
|
| Presentation Title |
Local Hot Corrosion of Aluminizing (NiAl) Coating Deposited by Vapor Phase Aluminizing (VPA) Process on 738LC, MAR 247 and CMSX4 Superalloys Substrates at 900 oC Under Na2SO4 Salt Deposit Films |
| Author(s) |
Ece Canan Karabastik, Batuhan Başbozkurt, Sercan Soyöz, Cevat Sarioglu |
| On-Site Speaker (Planned) |
Cevat Sarioglu |
| Abstract Scope |
In this work, NiAl aluminizing coatings were deposited by Vapor Phase Aluminizing (VPA) process on these superalloys substrates to improve cyclic and hot corrosion resistance. Hot corrosion tests of these alloys were performed under Na2SO4 salt deposit films at 900 oC up to 1008 hours. The characterization results of exposed surface and cross-section by OM, XRD and SEM indicated that the Al2O3 oxide layer formed at the beginning of exposure was attacked locally (resembling pitting corrosion attack) by salt deposits as early as 1 hour exposure regardless of substrate type. The local attacked regions were monitored with help of OM, XRD and SEM-EDS. After continuous alumina layer was destroyed locally completely as a pitting hot corrosion, salt deposits reached the bare NiAl coatings causing extensive hot corrosion of coating for all NiAl coated substrates. The hot corrosion mechanisms were reevaluated with respect to existing mechanisms reported in literature. |