Effect of Ce and La additions in low temperature aluminization process by CVD–FBR on 12%Cr ferritic/martensitic steel and behaviour in steam oxidation

• Published in: Corrosion science Vol. 50; no. 8; pp. 2318 - 2326
• Main Authors: Sánchez, L., Bolívar, F.J., Hierro, M.P., Pérez, F.J.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-08-2008; Elsevier
• Subjects: A. Metal coatings; A. Steel; Applied sciences; B. Modelling studies; C. High temperature corrosion; Corrosion; Corrosion environments; Exact sciences and technology; Metallic coatings; Metals. Metallurgy; Production techniques; Surface treatment; C. High temperature corrosion; A. Metal coatings; B. Modelling studies; A. Steel; Ferritic martensitic steel; Temperature; Martensitic steel; Composition effect; High temperature; Water vapor; Chemical vapor deposition; Modeling; Surface treatment; Aluminizing; Metal coating; Ferritic steel; Oxidation; High temperature corrosion; Low temperature
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2008.05.008

Two different coatings based of iron aluminide on 12% Cr ferritic–martensitic steel have been developed by CVD–FBR technique, which is modified by the introduction of Ce and La as powder in the fluidized bed. These elements change the gaseous environment, which composition is predicted by a thermodynamic approximation. Partial pressures of all gaseous precursors are drastically modified; in consequence AlCl has the highest partial pressure in the system leading to an increment of the coating thickness. Coatings are composed by (Fe,
Cr)
2Al
5 or (Fe,
Cr)
2Al
5 and (Fe,
Cr)Al
3 intermetallic phases. On the other hand, steam oxidation test at 650
°C was performed in order to observe improvements in the HCM12A oxidation resistant.