Metal dusting resistance of high chromium alloys
| Autor: | H. P. Martinz, E. M. Müller-Lorenz, Hans Jürgen Grabke |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Materials science
Mechanical Engineering Chromium Alloys Alloy Metallurgy Metals and Alloys chemistry.chemical_element General Medicine Coke engineering.material Chromia Surfaces Coatings and Films Corrosion Chromium chemistry Mechanics of Materials Powder metallurgy Metal dusting Materials Chemistry engineering Environmental Chemistry |
| Zdroj: | Materials and Corrosion. 54:860-863 |
| ISSN: | 1521-4176 0947-5117 |
| Popis: | Samples of 5 high Cr-alloys were discontinuously exposed for 10,000 hours under severe metal dusting conditions, i. e. in flowing 49%CO-49%H 2 -2%H 2 O at 650°C. After each of the 11 exposure periods the mass change was determined and any coke removed and weighed. Metallographic cross sections were prepared after about 4,000 h and 10,000 h. The high Cr-alloys: 1. PM 2000 (Fe-19%Cr-5.5%Al-0.5%Ti-0.5%Y 2 O 3 ), 2. Cr-44%Fe-5%Al-0.4%Ti-0.5%Y 2 O 3 , 3. Cr-50%Ni, 4. Cr-5%Fe-1%Y 2 O 3 and 5. porous chromium showed no or only minute metal dusting attack. Compared to the attack on reference samples of Alloy 601 (Ni-23%Cr-14%Fe-1.4%Al), the metal dusting symptoms were negligible on the 5 high Cr-alloys, minor coking and pitting and no internal carburization was observed. Because of the high Cr-content, carbon solution and ingress should be minute, and in addition are inhibited by the formation of a chromia scale, as confirmed for four of the Cr-rich alloys, and formation of an alumina scale on PM 2000. These alloys could be used for parts exposed to severe metal dusting conditions, and in fact, 50Cr-50Ni has been applied successfully under such conditions. |
| Databáze: | OpenAIRE |
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